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**Turning radius**
Turning radius:
The turning radius (alternatively, turning diameter or turning circle) of a vehicle defines the minimum dimension (typically the radius or diameter, respectively) of available space required for that vehicle to make a semi-circular U-turn without skidding. The Oxford English Dictionary describes turning circle as "the smallest circle within which a ship, motor vehicle, etc., can be turned round completely". The term thus refers to a theoretical minimal circle in which for example an aeroplane, a ground vehicle or a watercraft can be turned around.
Turning radius:
The terms (radius, diameter, or circle) can have different meanings; refer to the § Alternative nomenclature section.
Definition:
On wheeled vehicles with the common type of front wheel steering (i.e. one, two or even four wheels at the front capable of steering), the vehicle's turning diameter measures the minimum space needed to turn the vehicle around while the steering is set to its maximum displacement from the central 'straight ahead' position - i.e. either extreme left or right. If a marker pen was placed on the point of the vehicle furthest from the center of the turn, the diameter of the circle traced during the turn defines the value of that vehicle's turning diameter. Mathematically, the turning radius would be half of the turning diameter.
Definition:
The curb-to-curb turning radius, which considers the chassis and wheels only without body protrusions, can be expressed as a simplified function of the wheelbase, tire width, and steering angle: sin (steeringangle)+tirewidth2 Aircraft have a similar minimum turning circle concept, generally associated with a standard rate turn, in which an aircraft enters a coordinated turn which changes its heading at a rate of 3° per second, or 180° in one minute. In this case, the turning radius depends on the true airspeed vt (in knots) as: 60 π Turning diameter is sometimes used in everyday language as a generalized term rather than with numerical figures. For example, a wheeled vehicle with a very small turning circle may be described as having a "tight turning radius", meaning that it is easier to turn around very tight corners. Wheeled vehicles with four-wheel steering will have a smaller turning radius than vehicles that steer wheels on one axle.
Definition:
Exceptions Technically, the minimum possible turning circle for a vehicle would be where it does not move either forwards or backwards while turning and simply pivots on its central axis. For a rectangular vehicle capable of doing this, the smallest turning circle would be equal to the diagonal length of the vehicle. As an example, some boats can be turned in this way, generally by using azimuth thrusters.
Definition:
Some wheeled vehicles are designed to spin around their central axis by making all wheels steerable, such as certain lawnmowers and wheelchairs as they do not follow a circular path as they turn. In this case the vehicle is referred to as a "zero turning radius" vehicle. Some camera dollies used in the film industry have a "round" mode which allows them to spin around their z axis by allowing synchronized inverse rotation of their left and right wheel sets, effectively giving them "zero" turning radius.
Definition:
Many conventionally steerable vehicles (only one axle with steerable wheels) can reverse the direction of travel in a space smaller than the stated turning radius by executing a specialized maneuver, such as a J-turn or similar skid, or in a discontinuous motion such as a three-point turn.
Alternative nomenclature:
Other terms are sometimes used synonymously for turning diameter, which can lead to confusion.
Alternative nomenclature:
Turning radius and diameter The automotive term turning radius has been used as equivalent and interchangeable with the turning diameter. For example, the 2017 Audi A4 is specified by the manufacturer as having a turning diameter (curb-to-curb) of 11.6 m (38 ft). Mathematically, the radius of a circle is half the diameter, so the correct turning radius in this example would be 11.6 m/2 = 5.8 m. However, another source lists the turning radius of the same vehicle as also being 11.6 m, which is the turning diameter.
Alternative nomenclature:
In practice, the values of turning diameter tend to be listed more frequently in vehicle specifications, so the term turning diameter will therefore be more correct in most cases. The turning diameter will always give a higher number for a given vehicle, and the turning diameter measurement is usually preferred by automotive manufacturers. Such mixing of terms can lead to confusion among consumers.
Alternative nomenclature:
Turning circle The term turning circle is another term also sometimes used synonymously for the turning diameter. Some argue that turning circle is less ambiguous than turning radius, but "turning circle" may introduce its own ambiguities since the same circle can be defined by multiple measurements, including the radius r , diameter ( d=2⋅r , twice as big), or circumference ( 2πr , about 6.28 times as big). For example, Motor Trend refers to a "curb-to-curb turning circle" of a 2008 Cadillac CTS as 10.82 metres (35.5 ft), but the terminology is not yet settled. AutoChannel.com refers to the "turning radius" of the same car as 10.82 metres (35.5 ft).
Alternative nomenclature:
Turning circle is also sometimes used to refer to the path swept in the manoeuvre, i.e. the arc, or the circle's circumference in the case when the manoeuvre makes a complete turn.
Different measurement methods:
There are two methods for measuring the vehicle turning diameter which will give slightly different results. These two methods are called wall-to-wall and curb-to-curb (US spelling), or alternatively kerb-to-kerb (UK spelling).
Different measurement methods:
The wall-to-wall turning circle is the minimum distance between two walls, both of which exceed the height of the vehicle, in which the vehicle can make a U-turn. The kerb-to-kerb turning circle is the minimum distance between two raised curbs, both of which are lower than the lowest body protrusions, in which the vehicle can make a U-turn. The wall-to-wall turning circle is greater than the kerb-to-kerb measure for the same vehicle because of the front and rear body overhangs. One can find these two ways of measuring the turning circle used in auto specifications, for example, a van might be listed as having a turning circle (in meters) of 12.1 (C) / 12.4 (W).
Different measurement methods:
Curb-to-curb A curb or curb-to-curb turning circle will show the straight-line distance from one side of the circle to the other, through the center. The name "curb-to-curb" indicates that a street would have to be this wide before this car can make a U-turn and not hit a street curb with a wheel. If you took the street curb and built it higher, as high as the car, and tried to make a U-turn in the street, parts of the car (bumper) would hit the wall.
Different measurement methods:
The kerb-to-kerb turning circle can be smaller than the turning circle as it refers to only a partial circle (~180°) with the vehicle alongside one kerb to start with. To perform a U turn in a forward direction only, the centre of the turn is not coincident with the centre of the road - thus a complete circle would not be possible (without driving onto the pavement to complete the manoeuvre). It also does not take into account that part of the vehicle that overhangs the wheels where as 'turning circle' does.
Different measurement methods:
Wall-to-wall The name wall or wall-to-wall turning circle denotes how far apart the two walls would have to be to allow a U-turn without scraping the walls.
Legal requirements for road vehicles:
European Union and SwitzerlandRoad vehicles must be able to carry out a 360 degrees turn on an annulus with an outer radius of 12.5 metres (41 ft) and an inner radius of 5.3 metres (17 ft), measured wall-to-wall. In addition, when entering this annulus, no part of the vehicle can overreach a tangent by more than 80 centimetres (31 in); this tangent is drawn at the outer, 12.5 m limit of the annulus.
Legal requirements for road vehicles:
New ZealandNew Zealand requires that road vehicles can perform a 360 degrees turn on a circle with a 25 metres (82 ft) diameter, measured wall-to-wall. The only part of the vehicle that may reach over this limitation are collapsible mirrors. | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**Anubandha chatushtaya**
Anubandha chatushtaya:
Anubandha chatushtaya (Sanskrit: अनुबन्ध चतुष्टय) literally means four connections, and therefore, it is four-fold in nature and content viz, – a) adhikāri ('the qualified student') who has developed ekāgrata ('single pointed mind'), chitta shuddhi ('purity of the mind') and vikshepa ('freedom from restlessness and impurity') or adhikāra (aptitude); b) vishaya ('subject matter' or 'the theme') pertaining to the Jiva-Brahman identity; c) prayojana or phalasruti ('result' or 'fruit') which is atyantika-dukha-nivritti ('complete cessation of sorrow') and paramānanda-prāpti ('attainment of supreme happiness'), and d) sambandha ('relationship' or 'intertextuality') between adhikāra, vishaya and prayojana.
Methodology:
Sadananda reminds that:- तत्र अनुबन्धो नाम अधिकारिविषयसंबन्धप्रयोजनानि |"The preliminary questions of the Vedanta are the determination of the competency of the student, the subject-matter, its connection with the book and the necessity of for its study." – Vedantasara (sutra I.5)a)- Adhikāra is the capacity to study (adhyana) the subject-matter in which respect there exist doubts (sandigdhata) which is the basis of the intended inquiry into that particular subject-matter for the eventual removal of all doubts and gain of its proper understanding. Madhavacharya speaks about three levels of adhikāra – adhama ('lower'), madhyama ('middle') and uttama ('higher'), the last two levels indicate that the student is of peaceful mind (śanta), is understanding and has non-repressed sense-control (danta), has withdrawn from worldly objects (uparata), indifferent (titikśu) and composed and tranquil (samhita), and knows that he is adequately prepared to meet the truth face to face. The Mimāṃsakas consider adhikāra to be a notion of appropriateness. All things and actions have identifiable adhikāra. Adhikāra indicates the level of preparation necessary for making one skilled for higher gains. The concept of adhikāra also helps describe the relationship between purusha and prakrti and explain the reason for activation of creative power of nature, thus bringing about the experience of the world (darśana bhoga) and liberation from this experience (kaivalya). The eagerness to know incites the obligation (adhikāra) to bring about realization of knowledge. In this direction the student must firstly develop Ekāgratā ('one-pointed'). Ekagrata is the state of determined and continuous concentration obtained by integrating the psycho-mental flux (sarvārthatā i.e. variously directed, discontinuous, diffused attention) which is – योगश्चित्तवृत्तिनिरोधः (Yoga Sutra)- meaning – Yoga is suppression of psycho-mental states i.e. disappearance of all possible misconceptions. In this yogic state of ekagrata the yogi gains genuine will. Upasana brings about ekagrata, and upasana in its own turn is brought about by chitta shuddhi ('the purity of heart'); and controls vikshepa (all forms of mental wanderings or distractions).
Methodology:
In Sanskrit grammar, an adhikara is a 'heading rule' made belonging to it, by the accent of swarita with the object of avoiding a repeated designation.b)- Vishaya is the object of knowledge, here the subject-matter; the universal Self (Brahman) seemingly different from the individual self (Jiva). Knowledge reveals the real to be superimposed by the unreal on account of ignorance. As explained by Sadananda the subject is the one-ness of the individual soul and the universal soul (the Absolute) as explained by the Upanishads; this is the essence of the Vedanta. Consciousness, which is infinite and indivisible, is able to come into contact with objects and is inherent in objects which are thus very many varying phases of consciousness; such objects that are by themselves phases of consciousness are vishaya-caitanya, outside consciousness no object can exist.c)- Prayojana means - the 'purpose', 'end result' or 'resolution of the inquiry'; it is the established result arrived at after practice of devotion conducted with a peaceful mind and body (śānta bhāva). Uddyotakara explains that the basic urges for attainment of happiness and avoidance of sorrow, such as the chaturvarga composed of dharma, artha, kama and moksha, prompt human activity, and such motivations lead to the end results or prayojana. Vedānta Paribhāśa, recognizing this chaturvarga describes prayojana as that which when known is desired as one's own, Prayojana is the realizable purpose, the desired reason or motive which prompts actions but which cannot be indicated separately from sambandha, both being inter-related,d)- Sambandha does not necessarily identify either vishaya or prayojana though it can be factual and reasonable (siddha) or contrary to fact and reason (asiddha). Shankara tells us that the self is bodyless (aśarira) but its relationship (sambandha) with the body is asiddha because the self is unrelated to any activity of the body and unconnected with merit and demerit arising from activity notwithstanding the fact that the jiva erroneously identifies itself with the body. Vedantasara's afore-cited statement as an exposition of these four anubandhas ('connections') and in particular the connection called sambandha to mean – (quote) "the relation of what has to be made known in the Vedantic system, the identity between Brahman and the individual soul" (unquote).
Implication:
In Hindu philosophy, Anubandha chatushtaya is a traditional Indian rhetorical mode connected with the gain of knowledge and supreme perfection, which mode is based on four fundamental aspects of thoughts and actions working in-tandem which are – a) the proposed subject or theme, b) the intended goal and its nature, c) why for that goal is sought in the light of d) the subject opted and the anticipated apprehension of truth. Krishna assures Arjuna:- परं भूयः प्रवक्ष्यामि ज्ञानानां ज्ञानमुत्तमम् | यज्ज्ञात्वा मुनयः सर्वे परां सिद्धिमितो गताः ||"I shall again speak of that highest knowledge which is superior to any other knowledge, knowing which all the sages have attained the supreme perfection." Bhagavad Gita (XIV.1)and thereafter, proceeds to explain how that knowledge can be gained and developed which would eventually free a mumukshu ('seeker') who due to association with the modes of nature (prakrti) is entangled in this material world, and therefore, explains the nature of the three gunas. This particular statement is in the form of an Anubandha chatushtaya the subject-matter of which is Brahma Vidya, the goal is liberation from sorrow, and pryojanam is the knowledge of Brahman which gives spontaneous release. Krishna leads Arjuna to that knowledge of the self which reveals what the subject is, what the "I" is – Tat Tvam Asi , this is the relationship that helps the seeker, possessing basic qualities, to decide whether he should connect or associate with the subject-matter or not. | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**Topocide**
Topocide:
Topocide is the deliberate alteration or destruction of a locale through industrial expansion and change, so that its original landscape and character are destroyed.An alternative term is Domicide (from Latin domus, meaning home or abode, and caedo, meaning deliberate killing) the destruction of home; the two may be viewed as synonyms or they may be opposed, with topocide referring to destruction from the point of view of the perpetrator(s) and domicide from the perspective of those affected.Topocide can be the result of deliberate industrial expansion. When industries form, then the people's center of life revolve around that industry. New jobs are formed and the environmental and cultural landscape is forever changed.Historical examples include the destruction of Dresden at the end of World War II and the Khmer Rouge's destruction in Cambodia. | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**Photo blanket**
Photo blanket:
A photo blanket is a large, rectangular piece of fabric displaying images, pictures, or designs, often with bound edges, used as a blanket or decorative object. Historically photo blanket were made of thick cloth depicting people, objects, and symbols intended to tell a story or reveal historical events.
History:
The photo blanket has a history nearly as long as the history of clothing itself. For thousands of years, people around the world used blankets as a form of communication through storytelling, honoring dead, and a well-respected form of art.
Ancient Egyptians weaved colored threads and sometimes even gold into a fabric (usually linen) or by painting with inks and dyes on papyrus cloth. The cloth (blanket) would often form pictures to tell stories and to honor prominent people or one of the multiple gods of their culture.
History:
Navajo tribes used special indigo dye from Mexico and other vegetal dyes to color multi-ply yarns and weave them into three main types of blankets - a serape (a shoulder covering blanket that is longer than it is wide), a saddle blanket (a blanket that was folded in half under a horse’s saddle for extra cushioning), and a chief's blanket (a shoulder blanket that was made wider than it was long).Nepalese rug makers - one of the most respected jobs in their society - would use luxurious silks, wools, and hemp to create beautiful works or art. Using vertical looms and fibers dyed with natural vegetal dyes, they form several different types of knots together for a soft and evenly tufted finish.For hundreds of years, tribes throughout Indonesia and Africa have used a dye and resist technique called batik to create intricate patterns and pictures. During the past two or three centuries batik has become one of the principal means of expression of the spiritual and cultural values of Southeast Asia. Once again used as a form of storytelling and passing down history, picture fabrics and blankets have been an integral part of their culture.
History:
Asian cultures have used weaving and blankets for the same purposes, using gold and other precious metals woven into their cloths and blankets. As an important artistic form, it conveys the history and myths of a culture through iconography and pictures.
History:
Throughout history, photo blankets have been an ever present and fundamental key to communication, decoration, and tradition. Today’s photo blankets have changed to modern techniques and more efficient manufacturing, but the primary meaning has remained very similar. People display meaningful photos that represent memories and reveal history. Adding text or symbols communicate language and add to the blanket’s storytelling aspect.
Uses:
Photo blankets are used throughout the home for displaying pictures and images as objects of decor, for warmth, or to be given and received as gifts.
Uses in home decor include furniture coverings and as decorative displays of a design or photograph. Photo blankets can be used to cuddle up for warmth either in or outdoors. They are often given as wedding, birthday, Christmas, baby, or anniversary gifts to individuals or couples displaying memorable pictures, dates and quotes on them.
Types:
There are three main types of photo blankets - woven photo blankets, knitted photo blankets, and dyed photo blankets.
Types:
A woven photo blanket is made on a jacquard loom using digital software that scans a picture, creates a pattern and then creates a woven picture blanket using various colored yarns that interlace at 90 degree angles (see weave). Woven photo blankets, comes in two varieties; an afghan photo blanket and a tapestry photo blanket. The yarn used in the weave of an afghan photo blanket is the same thickness in both horizontal and vertical directions while a tapestry photo blanket is manufactured with yarn of two different diameters. In a tapestry photo blanket the thinner of the two yarns; i.e., the warp, actually consists of 6-8 different color strands of yarn which are combined in various ways, based on a photo, to re-create the colors as accurately as possible (even black and white). A knitted photo blanket is made by a machine that uses a similar scanning and pattern process, but instead of weaving the yarns together, knits them together in a looping technique (see knit). Often knitted photo blankets consist of limited colors due to the knitting process and the continuous thread forming loops in the process.
Types:
A dyed photo blanket is the newest type of photo blanket and is made by printing dye onto fabric from a digital image (see dye sublimation). This type allows for unlimited colors and has the sharpest picture clarity of the three. Each process creates a permanent picture, with varying degrees of softness, color and clarity. | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**Distinguishing attack**
Distinguishing attack:
In cryptography, a distinguishing attack is any form of cryptanalysis on data encrypted by a cipher that allows an attacker to distinguish the encrypted data from random data. Modern symmetric-key ciphers are specifically designed to be immune to such an attack. In other words, modern encryption schemes are pseudorandom permutations and are designed to have ciphertext indistinguishability. If an algorithm is found that can distinguish the output from random faster than a brute force search, then that is considered a break of the cipher.
Distinguishing attack:
A similar concept is the known-key distinguishing attack, whereby an attacker knows the key and can find a structural property in cipher, where the transformation from plaintext to ciphertext is not random.
Overview:
To prove that a cryptographic function is safe, it is often compared to a random oracle. If a function would be a random oracle, then an attacker is not able to predict any of the output of the function. If a function is distinguishable from a random oracle, it has non-random properties. That is, there exists a relation between different outputs, or between input and output, which can be used by an attacker for example to find (a part of) the input.
Overview:
Example Let T be a sequence of random bits, generated by a random oracle and S be a sequence generated by a pseudo-random bit generator. Two parties use one encryption system to encrypt a message M of length n as the bitwise XOR of M and the next n bits of T or S respectively. The output of the encryption using T is truly random. Now if the sequence S cannot be distinguished from T, the output of the encryption with S will appear random as well. If the sequence S is distinguishable, then the encryption of M with S may reveal information of M.
Overview:
Two systems S and T are said to be indistinguishable if there exists no algorithm D, connected to either S or T, able to decide whether it is connected to S or T.
Overview:
A distinguishing attack is given by such an algorithm D. It is broadly an attack in which the attacker is given a black box containing either an instance of the system under attack with an unknown key, or a random object in the domain that the system aims to emulate, then if the algorithm is able to tell whether the system or the random object is in the black box, one has an attack. For example, a distinguishing attack on a stream cipher such as RC4 might be one that determines whether a given stream of bytes is random or generated by RC4 with an unknown key.
Examples:
Classic examples of distinguishing attack on a popular stream cipher was by Itsik Mantin and Adi Shamir who showed that the 2nd output byte of RC4 was heavily biased toward zero. In another example, Souradyuti Paul and Bart Preneel of COSIC have shown that the XOR value of the 1st and 2nd outputs of RC4 is also non-uniform. Significantly, both the above theoretical biases can be demonstrable through computer simulation. | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**Entropy (magazine)**
Entropy (magazine):
Entropy is an online magazine that covers literary and related non-literary content. The magazine features personal essays, reviews, experimental literature, poetry, interviews, as well as writings on small press culture, video games, performance, graphic novels, interactive literature, science fiction, fantasy, music, film, art, translation, and other topics. Entropy's website also functions as a place where those within the literary community can interact.Since its launch, the magazine has attracted notable contributors, such as Will Alexander, John Vercher, Seo-Young Chu, Amish Trivedi, Gabino Iglesias, C. Kubasta, Justin Petropoulos, Daniel Borzutzky, Anne Casey, Michael J. Seidlinger, and others. It is widely known for its yearly lists of the best poetry, articles, music, and more. Entropy has also established a reputation as being as safe publishing space for essays written on the subject of #MeToo and related issues.In June 2017, Civil Coping Mechanisms, Entropy, and Writ Large Press created a partnership, known as The Accomplices. In August 2018, they formed The Accomplices LLC and launched their new website and cohesive brand in January 2019. The group publishes books, produces literary workshops and events, creates videos and other media, and runs a literary website and community space. | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**Gary Cziko**
Gary Cziko:
Gary Cziko is an American researcher, and author in the field of educational psychology at the University of Illinois at Urbana–Champaign who has worked on the philosophical model known as perceptual control theory (PCT) – a model whose original developer, William T. Powers, was his mentor. He has written two introductory books on the subject, and in 1995 he introduced the concept of "universal selectionism" into the PCT model.
Education and career:
Cziko received a Bachelor of Arts degree in psychology from Queens College, City University of New York, a Master of Arts degree in psychology from McGill University in Montreal, Quebec, Canada, in 1975, and a Doctor of Philosophy (Ph.D.) from McGill University in 1978.
He was a post-doctoral research fellow for the Quebec Ministry of Education at the University of Montreal during 1978–79. Since 1979, Cziko has been on the faculty of the University of Illinois at Urbana–Champaign. He became an associate professor in 1986 and a full professor in 1998.
Selected publications:
In 1989, Cziko published one of his first academic papers relating to PCT: Cziko, Gary (1989). "Unpredictability and Indeterminism in Human Behavior: Arguments and Implications for Educational Research" (PDF). Educational Researcher. 18 (3): 17–25. doi:10.3102/0013189X018003017. S2CID 17154755. Archived from the original (PDF) on January 24, 2013.He has also authored two introductions to PCT, both published by MIT Press: Cziko, Gary (1995). Without Miracles: Universal Selection Theory and the Second Darwinian Revolution. MIT Press. ISBN 0-262-03232-5. LCCN 95000943.
Selected publications:
Cziko, Gary (2000). The Things We Do : Using The Lessons of Bernard and Darwin to Understand The What, How, and Why of Our Behavior. MIT Press. ISBN 0-262-03277-5. LCCN 99051843.
Awards and recognitions:
In 2008, Cziko was a Fulbright Scholar in Chile. | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**Airstream mechanism**
Airstream mechanism:
In phonetics, the airstream mechanism is the method by which airflow is created in the vocal tract. Along with phonation and articulation, it is one of three main components of speech production. The airstream mechanism is mandatory for most sound production and constitutes the first part of this process, which is called initiation.
Airstream mechanism:
The organ generating the airstream is called the initiator and there are three initiators used phonemically in non-disordered human oral languages: the diaphragm together with the ribs and lungs (pulmonic mechanisms), the glottis (glottalic mechanisms), and the tongue (lingual or "velaric" mechanisms).There are also methods of making sounds that do not require the glottis. These mechanisms are collectively called alaryngeal speech mechanisms (none of these speech mechanisms are used in non-disordered speech): the cheeks (buccal mechanisms, notated {ↀ} in VoQS). See buccal speech.
Airstream mechanism:
after a laryngectomy, the esophagus may be used (notated {Œ} for simple esophageal speech, {Ю} for tracheo-esophageal speech in VoQS, and notated {И} for electrolaryngeal speech). See esophageal speech.
the pharynx, and replacing the glottis using the tongue and the upper alveolus, the palate, or the pharyngeal wall. See pharyngeal speech.Percussive consonants are produced without any airstream mechanism.
Types of airstream mechanism:
Any of the three principal initiators − diaphragm, glottis or tongue − may act by either increasing or decreasing the pressure generating the airstream. These changes in pressure often correspond to outward and inward airflow, and are therefore termed egressive and ingressive respectively.
Of these six resulting airstream mechanisms, four are found lexically around the world: pulmonic egressive, where the air is pushed out of the lungs by the ribs and diaphragm. All human languages employ such sounds (such as vowels), and nearly three out of four use them exclusively.
glottalic egressive, where the air column is compressed as the glottis moves upward. Such consonants are called ejectives. Ejective and ejective-like consonants occur in 16% of the languages.
Types of airstream mechanism:
glottalic ingressive, where the air column is rarefied as the glottis moves downward. Such consonants are called implosives. Implosive and implosive-like consonants occur in 13% of the world's languages. Despite the name, the airstream may not actually flow inward: While the glottis moves downward, pulmonic air passes outward through it, but the reduction in pressure makes an audible difference to the sound.
Types of airstream mechanism:
lingual ingressive, AKA velaric ingressive, where the air in the mouth is rarefied by a downward and sometimes rearward movement of the tongue. These are the click consonants. Clicks are regular sounds in ordinary (i.e. lexical) words in fewer than 2% of the world's languages, all in Africa.These mechanisms may be combined into airstream contours, such as clicks which release into ejectives.
Types of airstream mechanism:
In normal vocabulary, the various Khoisan languages have pulmonic, ejective, and click consonants; the Chadic languages, some Mayan languages, and scattered Nilo-Saharan languages such as Gumuz, Uduk and Meʼen have pulmonic, implosive, and ejective consonants, and the Nguni languages of the Bantu family utilize all four, – pulmonic, click, implosive, and ejective, – as does the Dahalo language of Kenya. Most other languages utilize at most two airstream mechanisms.
Types of airstream mechanism:
In interjections, the other two mechanisms may be employed. For example, in countries as diverse as Sweden, Turkey, and Togo, a pulmonic ingressive ("gasped" or "inhaled") vowel is used for back-channeling or to express agreement, and in France a lingual egressive (a "spurt") is used to express dismissal. The only language where such sounds are known to be contrastive in normal vocabulary is the extinct ritual language Damin (also the only language outside Africa with clicks); however, Damin appears to have been intentionally designed to differ from normal speech.
Pulmonic initiation:
Initiation by means of the lungs (actually the diaphragm and ribs) is called pulmonic initiation. The vast majority of sounds used in human languages are pulmonic egressives. In most languages, including all the languages of Europe (excluding the Caucasus), all phonemes are pulmonic egressives.
Pulmonic initiation:
The only attested use of a phonemic pulmonic ingressive is a lateral fricative in Damin, a ritual language formerly used by speakers of Lardil in Australia. This can be written with the extended version of the International Phonetic Alphabet as [ɬ↓]. !Xóõ has ingression as a phonetic detail in one series of its clicks, which are ingressive voiceless nasals with delayed aspiration, [↓ŋ̊ʘʰ ↓ŋ̊ǀʰ ↓ŋ̊ǁʰ ↓ŋ̊!ʰ ↓ŋ̊ǂʰ]. Peter Ladefoged considers these to be among the most difficult sounds in the world. Other languages, for example in Taiwan, have been claimed to have pulmonic ingressives, but these claims have either proven to be spurious or to be occasional phonetic detail.
Pulmonic initiation:
In interjections, but not in normal words, pulmonic ingressive vowels or words occur on all continents. This is commonly done for back-channeling (as with [ə↓] in Ewe) or affirmation (as with [ɸʷ↓] in Swedish). In English, an audible intake of breath, [hːː↓], or an indrawn consonant such as [tʰ↓] or [p͡t↓] is used in a conversation to indicate that someone is about to speak or is preparing to continue speaking. In some languages, such as Finnish and Amharic, entire phrases may be uttered with an ingressive airstream. (See ingressive sound.)
Glottalic initiation:
It is possible to initiate airflow in the upper vocal tract by means of the vocal cords or glottis. This is known as glottalic initiation.
Glottalic initiation:
For egressive glottalic initiation, one lowers the glottis (as if to sing a low note), closes it as for a glottal stop, and then raises it, building up pressure in the oral cavity and upper trachea. Glottalic egressives are called ejectives. The glottis must be fully closed to form glottalic egressives, or the air column would flow backwards over it; it is therefore impossible to pronounce voiced ejectives. Ejective allophones of voiceless stops occur in many varieties of English at the ends of intonation units.For ingressive glottalic initiation, the sequence of actions performed in glottalic pressure initiation is reversed: one raises the glottis (as if to sing a high note), closes it, and then lowers it to create suction in the upper trachea and oral cavity. Glottalic ingressives are called implosives, although they may involve zero airflow rather than actual inflow. Because the air column would flow forwards over the descending glottis, it is not necessary to fully close it, and implosives may be voiced; indeed, voiceless implosives are exceedingly rare.
Glottalic initiation:
It is usual for implosives to be voiced. Instead of keeping the glottis tightly closed, it is tensed but left slightly open to allow a thin stream of air through. Unlike pulmonic voiced sounds, in which a stream of air passes through a usually-fixed glottis, in voiced implosives a mobile glottis passes over a nearly motionless air column to cause vibration of the vocal cords. Phonations that are more open than modal voice, such as breathy voice, are not conducive to glottalic sounds because in these the glottis is held relatively open, allowing air to readily flow through and preventing a significant pressure difference from building up behind the articulator.
Glottalic initiation:
Because the oral cavity is so much smaller than the lungs, vowels and approximants cannot be pronounced with glottalic initiation. So-called glottalized vowels and other sonorants use the more common pulmonic egressive airstream mechanism.
Glottalic initiation:
There is no clear divide between pulmonic and glottalic sounds. Some languages may have consonants which are intermediate. For example, glottalized consonants in London English, such as the t in rat [ˈɹæʔt], may be weakly ejective. Similarly, fully voiced stops in languages such as Thai, Zulu, and Maidu are weakly implosive. This ambiguity does not occur with the next airstream mechanism, lingual, which is clearly distinct from pulmonic sounds.
Lingual (velaric) initiation:
The third form of initiation in human language is lingual or velaric initiation, where a sound is produced by a closure at two places of articulation, and the airstream is formed by movement of the body of the tongue. Lingual stops are more commonly known as clicks, and are almost universally ingressive. The word lingual is derived from Latin lingua, which means tongue.
Lingual (velaric) initiation:
To produce a lingual ingressive airstream, first close the vocal tract at two places: at the back of the tongue, as in a velar or uvular stop, and simultaneously with the front of the tongue or the lips, as in a coronal or bilabial stop. These holds may be voiceless, voiced, or nasalized. Then lower the body of the tongue to rarefy the air above it. The closure at the front of the tongue is opened first, as the click "release"; then the closure at the back is released for the pulmonic or glottalic click "accompaniment" or "efflux". This may be aspirated, affricated, or even ejective. Even when not ejective, it is not uncommon for the glottis to be closed as well, for a triply articulated consonant, and this third closure is released last to produce a glottalized click. Clicks are found in very few languages, notably the Khoisan languages of southern Africa and some nearby tongues such as Zulu. They are more often found in extra-linguistic contexts, such as the "tsk tsk" sound many Westerners use to express regret or pity (a dental click), or the clucking noise used by many equestrians to urge on their horses (a lateral click).
Lingual (velaric) initiation:
Lingual egressive initiation is performed by reversing the sequence of a lingual ingressive: the front and back of the tongue (or lips and back of the tongue) seal off the vocal cavity, and the cheeks and middle of the tongue move inward and upward to increase oral pressure. The only attested use of a lingual egressive is a bilabial nasal egressive click in Damin. Transcribing this also requires the use of the Extended IPA, [ŋʘ↑].
Lingual (velaric) initiation:
Since the air pocket used to initiate lingual consonants is so small, it is not thought to be possible to produce lingual fricatives, vowels, or other sounds which require continuous airflow.
Clicks may be voiced, but they are more easily nasalized. This may be because the vocal cavity behind the rearmost closure, behind which the air passing through the glottis for voicing must be contained, is so small that clicks cannot be voiced for long. Allowing the airstream to pass through the nose enables a longer production.
Lingual (velaric) initiation:
Nasal clicks involve a combination of lingual and pulmonic mechanisms. The velum is lowered so as to direct pulmonic airflow through the nasal cavity during the lingual initiation. This nasal airflow may itself be egressive or ingressive, independently of the lingual initiation of the click. Nasal clicks may be voiced, but are very commonly unvoiced and even aspirated, which is rare for purely pulmonic nasals.
Airstream contours:
In some treatments, complex clicks are posited to have airstream contours, in which the airstream changes between the front (click) and rear (non-click) release. There are two attested types: Linguo-pulmonic consonants, where the rear release is a uvular obstruent such as [q] or [χ]; and linguo-glottalic consonants, where the rear release is an ejective such as [qʼ] or [qχʼ]. Not only are simultaneous (rather than contour) implosive clicks possible, e.g. velar [ɠ͡ǂ] and uvular [ʛ͡ǂ], but velar implosive clicks are easier to produce than modally voiced clicks. However, they are not attested in any language.
Percussive consonants:
Consonants may be pronounced without any airstream mechanism. These are percussive consonants, where the sound is generated by one organ striking another. Percussive consonants are not phonemic in any known language, though the extensions to the IPA for disordered speech provide symbols for a bilabial percussive [ʬ] (smacking lips) and a bidental percussive [ʭ] (gnashing teeth). The only percussive known to be used in nondisordered speech is a sublingual percussive [¡] (a tongue slap) that appears allophonically in the release of alveolar clicks in the Sandawe language of Tanzania. | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**Special number field sieve**
Special number field sieve:
In number theory, a branch of mathematics, the special number field sieve (SNFS) is a special-purpose integer factorization algorithm. The general number field sieve (GNFS) was derived from it.
The special number field sieve is efficient for integers of the form re ± s, where r and s are small (for instance Mersenne numbers).
Heuristically, its complexity for factoring an integer n is of the form: exp 32 log log log 32 /9)1/3] in O and L-notations.
The SNFS has been used extensively by NFSNet (a volunteer distributed computing effort), NFS@Home and others to factorise numbers of the Cunningham project; for some time the records for integer factorization have been numbers factored by SNFS.
Overview of method:
The SNFS is based on an idea similar to the much simpler rational sieve; in particular, readers may find it helpful to read about the rational sieve first, before tackling the SNFS.
Overview of method:
The SNFS works as follows. Let n be the integer we want to factor. As in the rational sieve, the SNFS can be broken into two steps: First, find a large number of multiplicative relations among a factor base of elements of Z/nZ, such that the number of multiplicative relations is larger than the number of elements in the factor base.
Overview of method:
Second, multiply together subsets of these relations in such a way that all the exponents are even, resulting in congruences of the form a2≡b2 (mod n). These in turn immediately lead to factorizations of n: n=gcd(a+b,n)×gcd(a-b,n). If done right, it is almost certain that at least one such factorization will be nontrivial.The second step is identical to the case of the rational sieve, and is a straightforward linear algebra problem. The first step, however, is done in a different, more efficient way than the rational sieve, by utilizing number fields.
Details of method:
Let n be the integer we want to factor. We pick an irreducible polynomial f with integer coefficients, and an integer m such that f(m)≡0 (mod n) (we will explain how they are chosen in the next section). Let α be a root of f; we can then form the ring Z[α]. There is a unique ring homomorphism φ from Z[α] to Z/nZ that maps α to m. For simplicity, we'll assume that Z[α] is a unique factorization domain; the algorithm can be modified to work when it isn't, but then there are some additional complications.
Details of method:
Next, we set up two parallel factor bases, one in Z[α] and one in Z. The one in Z[α] consists of all the prime ideals in Z[α] whose norm is bounded by a chosen value max . The factor base in Z, as in the rational sieve case, consists of all prime integers up to some other bound.
We then search for relatively prime pairs of integers (a,b) such that: a+bm is smooth with respect to the factor base in Z (i.e., it is a product of elements in the factor base).
a+bα is smooth with respect to the factor base in Z[α]; given how we chose the factor base, this is equivalent to the norm of a+bα being divisible only by primes less than max .These pairs are found through a sieving process, analogous to the Sieve of Eratosthenes; this motivates the name "Number Field Sieve".
Details of method:
For each such pair, we can apply the ring homomorphism φ to the factorization of a+bα, and we can apply the canonical ring homomorphism from Z to Z/nZ to the factorization of a+bm. Setting these equal gives a multiplicative relation among elements of a bigger factor base in Z/nZ, and if we find enough pairs we can proceed to combine the relations and factor n, as described above.
Choice of parameters:
Not every number is an appropriate choice for the SNFS: you need to know in advance a polynomial f of appropriate degree (the optimal degree is conjectured to be log log log N)13 , which is 4, 5, or 6 for the sizes of N currently feasible to factorise) with small coefficients, and a value x such that mod N) where N is the number to factorise. There is an extra condition: x must satisfy mod N) for a and b no bigger than N1/d One set of numbers for which such polynomials exist are the ab±1 numbers from the Cunningham tables; for example, when NFSNET factored 479 +1 , they used the polynomial x6+3 with 80 , since 80 480 +3 , and 480 mod 479 +1) Numbers defined by linear recurrences, such as the Fibonacci and Lucas numbers, also have SNFS polynomials, but these are a little more difficult to construct. For example, 709 has polynomial 10 10 10 n+3 , and the value of x satisfies 142 141 =0 .If you already know some factors of a large SNFS-number, you can do the SNFS calculation modulo the remaining part; for the NFSNET example above, 479 158071 7167757 7759574882776161031 ) times a 197-digit composite number (the small factors were removed by ECM), and the SNFS was performed modulo the 197-digit number. The number of relations required by SNFS still depends on the size of the large number, but the individual calculations are quicker modulo the smaller number.
Limitations of algorithm:
This algorithm, as mentioned above, is very efficient for numbers of the form re±s, for r and s relatively small. It is also efficient for any integers which can be represented as a polynomial with small coefficients. This includes integers of the more general form are±bsf, and also for many integers whose binary representation has low Hamming weight. The reason for this is as follows: The Number Field Sieve performs sieving in two different fields.
Limitations of algorithm:
The first field is usually the rationals. The second is a higher degree field. The efficiency of the algorithm strongly depends on the norms of certain elements in these fields. When an integer can be represented as a polynomial with small coefficients, the norms that arise are much smaller than those that arise when an integer is represented by a general polynomial. The reason is that a general polynomial will have much larger coefficients, and the norms will be correspondingly larger. The algorithm attempts to factor these norms over a fixed set of prime numbers. When the norms are smaller, these numbers are more likely to factor. | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**Tienopramine**
Tienopramine:
Tienopramine is a tricyclic antidepressant (TCA) which was never marketed. It is an analogue of imipramine where one of the benzene rings has been replaced with a thiophene ring. | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**Gender paradox**
Gender paradox:
The gender paradox is a sociolinguistic phenomenon first observed by William Labov, who noted, "Women conform more closely than men to sociolinguistic norms that are overtly prescribed, but conform less than men when they are not." Specifically, the "paradox" arises from sociolinguistic data showing that women are more likely to use prestige forms and avoid stigmatized variants than men for a majority of linguistic variables, but that they are also more likely to lead language change by using innovative forms of variables.
Overview:
William Labov identifies three main principles that in combination, constitute the gender paradox. They illuminate the juxtaposing roles of women, who display both conformist and nonconformist behavior in the treatment of linguistic variables.
Overview:
Stable linguistic variables The first of the three principles states, "For stable sociolinguistic variables, women show a lower rate of stigmatized variants and a higher rate of prestige variants than men." The principle gives the most general understanding of women's treatment of linguistic variables, in that when variables are not undergoing any change, women tend to prefer the standard form of the variable to the non-standard form. It is a commonly occurring phenomenon that sociolinguists have observed in a wide array of societies. Peter Trudgill's study of the (ng) variable in Norwich, England provides evidence to support this principle.
Overview:
In his 1968 study, Trudgill studied the frequency of the (ng) variable among sixty random subjects and calculated the usage of the standard form [ɪŋ] versus that of the non-standard form [ən ~ n̩]. He classified his results into categories of class, style and sex. Women tended to avoid the stigmatized form and would prefer the standard form more than men did, which hold true for nearly all English dialects. Women were even more careful with their choice in variable when they spoke formally, which indicated a high level of linguistic awareness.
Overview:
Changes from above Occasionally considered a corollary to the first principle, the second principle states, "In linguistic change from above, women adopt prestige forms at a higher rate than men." These are language changes that individuals are generally conscious of. People are aware of the prestige associated with formal styles and thus are prone to hypercorrection – a product of linguistic insecurity. Several studies have shown that women are leaders both in eliminating stigmatized forms and adopting incoming prestige forms, and they do so at a notably higher rate than men.
Overview:
This finding is widespread across languages and can be seen in examples such as (r)-pronunciation in New York City, the reversal of the Parisian French chain shift, and entire language shifts, like that from Hungarian to German in Austria.
Overview:
Changes from below The third principle is as follows: "In linguistic change from below, women use higher frequencies of innovative forms than men do." Those changes, which generally occur below the level of social consciousness, are "the primary form of linguistic change that operates within the system." In these cases, women are the initiators and leaders of changes in progress.
Overview:
The Northern Cities Shift (NCS) offers a clear example of women leading change from below. For instance, The Atlas of North American English provides data on the regression analysis of 56 speakers in the Inland North in which the most significant factor regarding sound change advancement is gender, with women being the leading innovators. Women-led sound change from below is particularly salient for new and vigorous changes, like that of the palatalization of /t/ and /d/ in Cairo Arabic.
Explanations:
Researchers in sociolinguistics have attempted to provide a unified account and explanation for the gender paradox, with varying levels of success.
Explanations:
Neurobiological view One proposed explanation from J. K. Chambers is the notion that women lead sound change because of some inherent biological verbal advantage. Under that view, women command a greater range of variants and styles, despite similar gender roles, because of sex differences. That view is contradicted by the varying size of the "gender gap" and the fact that differences have not remained constant over time. Labov asserts that if Chambers's biological explanation were to hold true, it would need to produce a robust effect across generations.
Explanations:
Social capital view Another possible explanation for women's leadership in language change is their greater sensitivity to the social status associated with certain variants. As women have historically been denied access to the standard economic capital available to men through education and job opportunities, that may have motivated the usage of prestige forms to help them gain social capital and advance their social standing, both consciously for cases of change from above and subconsciously for change from below. The notion that women's speech is in fact the "language of powerlessness" is supported by findings that some features of stereotypical women's speech were also used by men when in a position of subverted power.
Explanations:
However, that view fails to address the consistently higher use of prestige forms even in contemporary societies with high levels of gender equality. Studies of language variation in central Sweden show that gender differences in speech have been maintained or even increased since 1967 although recent legislation in Sweden has led to widespread gender equality. Nonetheless, the legislation may be too recent to have any great effect on the power entrenched in language and the inherent sexism that might remain despite various new laws, but that would not explain the increases, and belies the likelihood that 57 years, three or four generations, of legislation is more than enough time to produce an effect.
Explanations:
Network theory view Gendered patterns of speech can also be explained by social network theory, which suggests that speech differences are accounted for by the differences between the social networks of men and women. Men tend to have denser and more local social networks, which are more conservative and resistant to change and result in higher usage of non-standard local variants. On the other hand, women tend to have more open and less local networks, which are more likely to use standard variants and have access to innovative forms because of weak ties to other speech communities. Of course, if the differences are cross-cultural, that would also suggest that biological differences are at play.
Complications:
In addition to the difficulties that arise in reconciling the gender paradox itself, other complications have emerged in the methodology and interpretations that led to its discovery.
Complications:
Ethnocentric data Evidence of the paradox is widespread in sociolinguistic variation studies that use either sex or gender as a variable, but findings that support the principles are not universal. Most data in support of the gender paradox come from studies of Indo-European languages in Europe or North America, but studies done in Asia, Africa, and the Middle East countries often show contradictory patterns. For example, male speakers use the prestigious classical variety of Arabic far more than women even though women lead in the use of locally-prestigious standard variants. Men speaking Malagasy also lead in the use of their ideal speech style, which is characterized by non-confrontational indirectness, but the women are norm-breakers and use the stigmatized direct style that is associated with negative information. Those counterexamples suggest that the gender paradox could be limited to Western cultures or languages.
Complications:
Stylistic differences within women Several sociolinguists question the validity of making generalizations about a group as large as "women," which makes up roughly half the population of the world. Penelope Eckert argues instead that women are not using prestige forms to declare whether or not they are women. A single linguistic variable can be indexical of multiple traits and women (and men) can belong to multiple social groups, each with their own linguistic traits. Language variations that are chosen by their third-order indexical qualities on a personal, rather than gender-wide level, reflected in the fact that no two women speak exactly alike. Those findings challenge the idea that women's use of prestige forms is not necessarily something inherent in their biology but could also be an external third-order indexical quality more highly valued among women than men.
Complications:
Social-constructionist view Social constructionists view the gender paradox as questionable because many of the studies used as evidence fail to take into account the sex and gender distinction. When gender is mentioned at all, it is often used synonymously with sex. Statistics support the fact that women often lead language change, but their motivations for doing so cannot be determined by statistics alone. It is inconclusive whether it is something physiologically inherent that makes women more progressive in their language use or if the trend is instead an effect of the role of the female gender within society.
Complications:
If a tendency towards language change is a product of gender, which is socially constructed, sociolinguistics should instead be focusing on the social aspects of femininity that are indexed by female speech. Tats view would also account for the inconsistency in results between studies done in western cultures supporting the gender paradox and those done in other cultures in where the results are less conclusive.
Complications:
Shifting of standard forms Variation among women could also be caused by shifting standard forms. In a 2003 study of the multilingual community of Palau, Kazuko Matsumoto and David Britain examined the functions of prestige forms among women of various age groups. They found that among Palau women of the parent and grandparent generations, the use of Japanese is considered a conservative behavior since it is used to preserve their ethnic home language. Among young Palau women, however, the use of Japanese is considered an innovative behavior because since they have been raised speaking Palau, Japanese is an prestigious foreign language, which is used to secure a job in the modern employment market. | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**Psychedelic rock**
Psychedelic rock:
Psychedelic rock is a rock music genre that is inspired, influenced, or representative of psychedelic culture, which is centered on perception-altering hallucinogenic drugs. The music incorporated new electronic sound effects and recording techniques, extended instrumental solos, and improvisation. Many psychedelic groups differ in style, and the label is often applied spuriously.Originating in the mid-1960s among British and American musicians, the sound of psychedelic rock invokes three core effects of LSD: depersonalization, dechronicization, and dynamization, all of which detach the user from everyday reality. Musically, the effects may be represented via novelty studio tricks, electronic or non-Western instrumentation, disjunctive song structures, and extended instrumental segments. Some of the earlier 1960s psychedelic rock musicians were based in folk, jazz, and the blues, while others showcased an explicit Indian classical influence called "raga rock". In the 1960s, there existed two main variants of the genre: the more whimsical, surrealist British psychedelia and the harder American West Coast "acid rock". While "acid rock" is sometimes deployed interchangeably with the term "psychedelic rock", it also refers more specifically to the heavier, harder, and more extreme ends of the genre.
Psychedelic rock:
The peak years of psychedelic rock were between 1967 and 1969, with milestone events including the 1967 Summer of Love and the 1969 Woodstock Rock Festival, becoming an international musical movement associated with a widespread counterculture before beginning a decline as changing attitudes, the loss of some key individuals, and a back-to-basics movement led surviving performers to move into new musical areas. The genre bridged the transition from early blues and folk-based rock to progressive rock and hard rock, and as a result contributed to the development of sub-genres such as heavy metal. Since the late 1970s it has been revived in various forms of neo-psychedelia.
Definition:
As a musical style, psychedelic rock incorporated new electronic sound effects and recording effects, extended solos, and improvisation. Features mentioned in relation to the genre include: electric guitars, often used with feedback, wah-wah and fuzzbox effects units; certain studio effects (principally in British psychedelia), such as backwards tapes, panning, phasing, long delay loops, and extreme reverb; elements of Indian music and other Eastern music, including Middle Eastern modalities; non-Western instruments (especially in British psychedelia), specifically those originally used in Indian classical music, such as sitar, tambura and tabla; elements of free-form jazz; a strong keyboard presence, especially electronic organs, harpsichords, or the Mellotron (an early tape-driven sampler); extended instrumental segments, especially guitar solos, or jams; disjunctive song structures, occasional key and time signature changes, modal melodies and drones; droning quality in vocals; electronic instruments such as synthesizers and the theremin; lyrics that made direct or indirect reference to hallucinogenic drugs; surreal, whimsical, esoterically or literary-inspired lyrics with (especially in British psychedelia) references to childhood; Victorian-era antiquation (exclusive to British psychedelia), drawing on items such as music boxes, music hall nostalgia and circus sounds.The term "psychedelic" was coined in 1956 by psychiatrist Humphry Osmond in a letter to LSD exponent Aldous Huxley and used as an alternative descriptor for hallucinogenic drugs in the context of psychedelic psychotherapy. As the countercultural scene developed in San Francisco, the terms acid rock and psychedelic rock were used in 1966 to describe the new drug-influenced music and were being widely used by 1967. The two terms are often used interchangeably, but acid rock may be distinguished as a more extreme variation that was heavier, louder, relied on long jams, focused more directly on LSD, and made greater use of distortion.
Original psychedelic era:
1960–65: Precursors and influences Music critic Richie Unterberger says that attempts to "pin down" the first psychedelic record are "nearly as elusive as trying to name the first rock & roll record". Some of the "far-fetched claims" include the instrumental "Telstar" (produced by Joe Meek for the Tornados in 1962) and the Dave Clark Five's "massively reverb-laden" "Any Way You Want It" (1964). The first mention of LSD on a rock record was the Gamblers' 1960 surf instrumental "LSD 25". A 1962 single by the Ventures, "The 2000 Pound Bee", issued forth the buzz of a distorted, "fuzztone" guitar, and the quest into "the possibilities of heavy, transistorised distortion" and other effects, like improved reverb and echo began in earnest on London's fertile rock 'n' roll scene. By 1964 fuzztone could be heard on singles by P.J. Proby, and the Beatles had employed feedback in "I Feel Fine", their sixth consecutive number 1 hit in the UK.According to AllMusic, the emergence of psychedelic rock in the mid-1960s resulted from British groups who made up the British Invasion of the US market and folk rock bands seeking to broaden "the sonic possibilities of their music". Writing in his 1969 book The Rock Revolution, Arnold Shaw said the genre in its American form represented generational escapism, which he identified as a development of youth culture's "protest against the sexual taboos, racism, violence, hypocrisy and materialism of adult life".American folk singer Bob Dylan's influence was central to the creation of the folk rock movement in 1965, and his lyrics remained a touchstone for the psychedelic songwriters of the late 1960s. Virtuoso sitarist Ravi Shankar had begun in 1956 a mission to bring Indian classical music to the West, inspiring jazz, classical and folk musicians. By the mid-1960s, his influence extended to a generation of young rock musicians who soon made raga rock part of the psychedelic rock aesthetic and one of the many intersecting cultural motifs of the era. In the British folk scene, blues, drugs, jazz and Eastern influences blended in the early 1960s work of Davy Graham, who adopted modal guitar tunings to transpose Indian ragas and Celtic reels. Graham was highly influential on Scottish folk virtuoso Bert Jansch and other pioneering guitarists across a spectrum of styles and genres in the mid-1960s. Jazz saxophonist and composer John Coltrane had a similar impact, as the exotic sounds on his albums My Favorite Things (1960) and A Love Supreme (1965), the latter influenced by the ragas of Shankar, were source material for guitar players and others looking to improvise or "jam".One of the first musical uses of the term "psychedelic" in the folk scene was by the New York-based folk group The Holy Modal Rounders on their version of Lead Belly's 'Hesitation Blues' in 1964. Folk/avant-garde guitarist John Fahey recorded several songs in the early 1960s experimented with unusual recording techniques, including backwards tapes, and novel instrumental accompaniment including flute and sitar. His nineteen-minute "The Great San Bernardino Birthday Party" "anticipated elements of psychedelia with its nervy improvisations and odd guitar tunings". Similarly, folk guitarist Sandy Bull's early work "incorporated elements of folk, jazz, and Indian and Arabic-influenced dronish modes". His 1963 album Fantasias for Guitar and Banjo explores various styles and "could also be accurately described as one of the very first psychedelic records".
Original psychedelic era:
1965: Formative psychedelic scenes and sounds Barry Miles, a leading figure in the 1960s UK underground, says that "Hippies didn't just pop up overnight" and that "1965 was the first year in which a discernible youth movement began to emerge [in the US]. Many of the key 'psychedelic' rock bands formed this year." On the US West Coast, underground chemist Augustus Owsley Stanley III and Ken Kesey (along with his followers known as the Merry Pranksters) helped thousands of people take uncontrolled trips at Kesey's Acid Tests and in the new psychedelic dance halls. In Britain, Michael Hollingshead opened the World Psychedelic Centre and Beat Generation poets Allen Ginsberg, Lawrence Ferlinghetti and Gregory Corso read at the Royal Albert Hall. Miles adds: "The readings acted as a catalyst for underground activity in London, as people suddenly realized just how many like-minded people there were around. This was also the year that London began to blossom into colour with the opening of the Granny Takes a Trip and Hung On You clothes shops." Thanks to media coverage, use of LSD became widespread.According to music critic Jim DeRogatis, writing in his book on psychedelic rock, Turn on Your Mind, the Beatles are seen as the "Acid Apostles of the New Age". Producer George Martin, who was initially known as a specialist in comedy and novelty records, responded to the Beatles' requests by providing a range of studio tricks that ensured the group played a leading role in the development of psychedelic effects. Anticipating their overtly psychedelic work, "Ticket to Ride" (April 1965) introduced a subtle, drug-inspired drone suggestive of India, played on rhythm guitar. Musicologist William Echard writes that the Beatles employed several techniques in the years up to 1965 that soon became elements of psychedelic music, an approach he describes as "cognate" and reflective of how they, like the Yardbirds, were early pioneers in psychedelia. As important aspects the group brought to the genre, Echard cites the Beatles' rhythmic originality and unpredictability; "true" tonal ambiguity; leadership in incorporating elements from Indian music and studio techniques such as vari-speed, tape loops and reverse tape sounds; and their embrace of the avant-garde.
Original psychedelic era:
In Unterberger's opinion, the Byrds, emerging from the Los Angeles folk rock scene, and the Yardbirds, from England's blues scene, were more responsible than the Beatles for "sounding the psychedelic siren". Drug use and attempts at psychedelic music moved out of acoustic folk-based music towards rock soon after the Byrds, inspired by the Beatles' 1964 film A Hard Day's Night, adopted electric instruments to produce a chart-topping version of Dylan's "Mr. Tambourine Man" in the summer of 1965. On the Yardbirds, Unterberger identifies lead guitarist Jeff Beck as having "laid the blueprint for psychedelic guitar", and says that their "ominous minor key melodies, hyperactive instrumental breaks (called rave-ups), unpredictable tempo changes, and use of Gregorian chants" helped to define the "manic eclecticism" typical of early psychedelic rock. The band's "Heart Full of Soul" (June 1965), which includes a distorted guitar riff that replicates the sound of a sitar, peaked at number 2 in the UK and number 9 in the US. In Echard's description, the song "carried the energy of a new scene" as the guitar-hero phenomenon emerged in rock, and it heralded the arrival of new Eastern sounds. The Kinks provided the first example of sustained Indian-style drone in rock when they used open-tuned guitars to mimic the tambura on "See My Friends" (July 1965), which became a top 10 hit in the UK.
Original psychedelic era:
The Beatles' "Norwegian Wood" from the December 1965 album Rubber Soul marked the first released recording on which a member of a Western rock group played the sitar. The song sparked a craze for the sitar and other Indian instrumentation – a trend that fueled the growth of raga rock as the India exotic became part of the essence of psychedelic rock. Music historian George Case recognises Rubber Soul as the first of two Beatles albums that "marked the authentic beginning of the psychedelic era", while music critic Robert Christgau similarly wrote that "Psychedelia starts here". San Francisco historian Charles Perry recalled the album being "the soundtrack of the Haight-Ashbury, Berkeley and the whole circuit", as pre-hippie youths suspected that the songs were inspired by drugs.
Original psychedelic era:
Although psychedelia was introduced in Los Angeles through the Byrds, according to Shaw, San Francisco emerged as the movement's capital on the West Coast. Several California-based folk acts followed the Byrds into folk rock, bringing their psychedelic influences with them, to produce the "San Francisco Sound". Music historian Simon Philo writes that although some commentators would state that the centre of influence had moved from London to California by 1967, it was British acts like the Beatles and the Rolling Stones that helped inspire and "nourish" the new American music in the mid-1960s, especially in the formative San Francisco scene. The music scene there developed in the city's Haight-Ashbury neighborhood in 1965 at basement shows organised by Chet Helms of the Family Dog; and as Jefferson Airplane founder Marty Balin and investors opened The Matrix nightclub that summer and began booking his and other local bands such as the Grateful Dead, the Steve Miller Band and Country Joe & the Fish. Helms and San Francisco Mime Troupe manager Bill Graham in the fall of 1965 organised larger scale multi-media community events/benefits featuring the Airplane, the Diggers and Allen Ginsberg. By early 1966 Graham had secured booking at The Fillmore, and Helms at the Avalon Ballroom, where in-house psychedelic-themed light shows replicated the visual effects of the psychedelic experience. Graham became a major figure in the growth of psychedelic rock, attracting most of the major psychedelic rock bands of the day to The Fillmore.According to author Kevin McEneaney, the Grateful Dead "invented" acid rock in front of a crowd of concertgoers in San Jose, California on 4 December 1965, the date of the second Acid Test held by novelist Ken Kesey and the Merry Pranksters. Their stage performance involved the use of strobe lights to reproduce LSD's "surrealistic fragmenting" or "vivid isolating of caught moments". The Acid Test experiments subsequently launched the entire psychedelic subculture.
Original psychedelic era:
1966: Growth and early popularity Echard writes that in 1966, "the psychedelic implications" advanced by recent rock experiments "became fully explicit and much more widely distributed", and by the end of the year, "most of the key elements of psychedelic topicality had been at least broached." DeRogatis says the start of psychedelic (or acid) rock is "best listed at 1966". Music journalists Pete Prown and Harvey P. Newquist locate the "peak years" of psychedelic rock between 1966 and 1969. In 1966, media coverage of rock music changed considerably as the music became reevaluated as a new form of art in tandem with the growing psychedelic community.
Original psychedelic era:
In February and March, two singles were released that later achieved recognition as the first psychedelic hits: the Yardbirds' "Shapes of Things" and the Byrds' "Eight Miles High". The former reached number 3 in the UK and number 11 in the US, and continued the Yardbirds' exploration of guitar effects, Eastern-sounding scales, and shifting rhythms. By overdubbing guitar parts, Beck layered multiple takes for his solo, which included extensive use of fuzz tone and harmonic feedback. The song's lyrics, which Unterberger describes as "stream-of-consciousness", have been interpreted as pro-environmental or anti-war. The Yardbirds became the first British band to have the term "psychedelic" applied to one of its songs. On "Eight Miles High", Roger McGuinn's 12-string Rickenbacker guitar provided a psychedelic interpretation of free jazz and Indian raga, channelling Coltrane and Shankar, respectively. The song's lyrics were widely taken to refer to drug use, although the Byrds denied it at the time. "Eight Miles High" peaked at number 14 in the US and reached the top 30 in the UK.Contributing to psychedelia's emergence into the pop mainstream was the release of the Beach Boys' Pet Sounds (May 1966) and the Beatles' Revolver (August 1966). Often considered one of the earliest albums in the canon of psychedelic rock, Pet Sounds contained many elements that would be incorporated into psychedelia, with its artful experiments, psychedelic lyrics based on emotional longings and self-doubts, elaborate sound effects and new sounds on both conventional and unconventional instruments. The album track "I Just Wasn't Made for These Times" contained the first use of theremin sounds on a rock record. Scholar Philip Auslander says that even though psychedelic music is not normally associated with the Beach Boys, the "odd directions" and experiments in Pet Sounds "put it all on the map. ... basically that sort of opened the door – not for groups to be formed or to start to make music, but certainly to become as visible as say Jefferson Airplane or somebody like that." DeRogatis views Revolver as another of "the first psychedelic rock masterpieces", along with Pet Sounds. The Beatles' May 1966 B-side "Rain", recorded during the Revolver sessions, was the first pop recording to contain reversed sounds. Together with further studio tricks such as varispeed, the song includes a droning melody that reflected the band's growing interest in non-Western musical form and lyrics conveying the division between an enlightened psychedelic outlook and conformism. Philo cites "Rain" as "the birth of British psychedelic rock" and describes Revolver as "[the] most sustained deployment of Indian instruments, musical form and even religious philosophy" heard in popular music up to that time. Author Steve Turner recognises the Beatles' success in conveying an LSD-inspired worldview on Revolver, particularly with "Tomorrow Never Knows", as having "opened the doors to psychedelic rock (or acid rock)". In author Shawn Levy's description, it was "the first true drug album, not [just] a pop record with some druggy insinuations", while musicologists Russell Reising and Jim LeBlanc credit the Beatles with "set[ting] the stage for an important subgenre of psychedelic music, that of the messianic pronouncement".Echard highlights early records by the 13th Floor Elevators and Love among the key psychedelic releases of 1966, along with "Shapes of Things", "Eight Miles High", "Rain" and Revolver. Originating from Austin, Texas, the first of these new bands came to the genre via the garage scene before releasing their debut album, The Psychedelic Sounds of the 13th Floor Elevators in October that year. It was one of the first rock albums to include the adjective in its title, although the LP was released on an independent label and was little noticed at the time. Two other bands also used the word in titles of LPs released in November 1966: The Blues Magoos' Psychedelic Lollipop, and the Deep's Psychedelic Moods. Having formed in late 1965 with the aim of spreading LSD consciousness, the Elevators commissioned business cards containing an image of the third eye and the caption "Psychedelic rock". Rolling Stone highlights the 13th Floor Elevators as arguably "the most important early progenitors of psychedelic garage rock".Donovan's July 1966 single "Sunshine Superman" became one of the first psychedelic pop/rock singles to top the Billboard charts in the US. Influenced by Aldous Huxley’s The Doors of Perception, and with lyrics referencing LSD, it contributed to bringing psychedelia to the mainstream.The Beach Boys' October 1966 single "Good Vibrations" was another early pop song to incorporate psychedelic lyrics and sounds. The single's success prompted an unexpected revival in theremins and increased the awareness of analog synthesizers. As psychedelia gained prominence, Beach Boys-style harmonies would be ingrained into the newer psychedelic pop.
Original psychedelic era:
1967–69: Continued development Peak era In 1967, psychedelic rock received widespread media attention and a larger audience beyond local psychedelic communities. From 1967 to 1968, it was the prevailing sound of rock music, either in the more whimsical British variant, or the harder American West Coast acid rock. Music historian David Simonelli says the genre's commercial peak lasted "a brief year", with San Francisco and London recognised as the two key cultural centres. Compared with the American form, British psychedelic music was often more arty in its experimentation, and it tended to stick within pop song structures. Music journalist Mark Prendergast writes that it was only in US garage-band psychedelia that the often whimsical traits of UK psychedelic music were found. He says that aside from the work of the Byrds, Love and the Doors, there were three categories of US psychedelia: the "acid jams" of the San Francisco bands, who favoured albums over singles; pop psychedelia typified by groups such as the Beach Boys and Buffalo Springfield; and the "wigged-out" music of bands following in the example of the Beatles and the Yardbirds, such as the Electric Prunes, the Nazz, the Chocolate Watchband and the Seeds.In February 1967, the Beatles released the double A-side single "Strawberry Fields Forever" / "Penny Lane", which Ian MacDonald says launched both the "English pop-pastoral mood" typified by bands such as Pink Floyd, Family, Traffic and Fairport Convention, and English psychedelia's LSD-inspired preoccupation with "nostalgia for the innocent vision of a child". The Mellotron parts on "Strawberry Fields Forever" remain the most celebrated example of the instrument on a pop or rock recording. According to Simonelli, the two songs heralded the Beatles' brand of Romanticism as a central tenet of psychedelic rock.
Original psychedelic era:
Jefferson Airplane's Surrealistic Pillow (February 1967) was one of the first albums to come out of San Francisco that sold well enough to bring national attention to the city's music scene. The LP tracks "White Rabbit" and "Somebody to Love" subsequently became top 10 hits in the US.The Hollies psychedelic B-side "All the World Is Love" (February 1967) was released as the flipside to the hit single "On a Carousel".Pink Floyd's "Arnold Layne" (March 1967) and "See Emily Play" (June 1967), both written by Syd Barrett, helped set the pattern for pop-psychedelia in the UK. There, "underground" venues like the UFO Club, Middle Earth Club, The Roundhouse, the Country Club and the Art Lab drew capacity audiences with psychedelic rock and ground-breaking liquid light shows. A major figure in the development of British psychedelia was the American promoter and record producer Joe Boyd, who moved to London in 1966. He co-founded venues including the UFO Club, produced Pink Floyd's "Arnold Layne", and went on to manage folk and folk rock acts including Nick Drake, the Incredible String Band and Fairport Convention.Psychedelic rock's popularity accelerated following the release of the Beatles' album Sgt. Pepper's Lonely Hearts Club Band (May 1967) and the staging of the Monterey Pop Festival in June. Sgt. Pepper was the first commercially successful work that critics recognised as a landmark aspect of psychedelia, and the Beatles' mass appeal meant that the record was played virtually everywhere. The album was highly influential on bands in the US psychedelic rock scene and its elevation of the LP format benefited the San Francisco bands. Among many changes brought about by its success, artists sought to imitate its psychedelic effects and devoted more time to creating their albums; the counterculture was scrutinised by musicians; and acts adopted its non-conformist sentiments.The 1967 Summer of Love saw a huge number of young people from across America and the world travel to Haight-Ashbury, boosting the area's population from 15,000 to around 100,000. It was prefaced by the Human Be-In event in March and reached its peak at the Monterey Pop Festival in June, the latter helping to make major American stars of Janis Joplin, lead singer of Big Brother and the Holding Company, Jimi Hendrix, and the Who. Several established British acts joined the psychedelic revolution, including Eric Burdon (previously of the Animals) and the Who, whose The Who Sell Out (December 1967) included the psychedelic-influenced "I Can See for Miles" and "Armenia City in the Sky". Other major British Invasion acts who absorbed psychedelia in 1967 include the Hollies with the album Butterfly, and The Rolling Stones album Their Satanic Majesties Request. The Incredible String Band's The 5000 Spirits or the Layers of the Onion (July 1967) developed their folk music into a pastoral form of psychedelia.Many famous established recording artists from the early rock era also fell under psychedelia and recorded psychedelic-inspired tracks, including Del Shannon's "Color Flashing Hair", Bobby Vee's "I May Be Gone", The Four Seasons' "Watch the Flowers Grow", Roy Orbison's "Southbound Jericho Parkway" and The Everly Brothers' "Mary Jane".According to author Edward Macan, there ultimately existed three distinct branches of British psychedelic music. The first, dominated by Cream, the Yardbirds and Hendrix, was founded on a heavy, electric adaptation of the blues played by the Rolling Stones, adding elements such as the Who's power chord style and feedback. The second, considerably more complex form drew strongly from jazz sources and was typified by Traffic, Colosseum, If, and Canterbury scene bands such as Soft Machine and Caravan. The third branch, represented by the Moody Blues, Pink Floyd, Procol Harum and the Nice, was influenced by the later music of the Beatles. Several of the post-Sgt. Pepper English psychedelic groups developed the Beatles' classical influences further than either the Beatles or contemporaneous West Coast psychedelic bands. Among such groups, the Pretty Things abandoned their R&B roots to create S.F. Sorrow (December 1968), the first example of a psychedelic rock opera.
Original psychedelic era:
International variants The US and UK were the major centres of psychedelic music, but in the late 1960s scenes began to develop across the world, including continental Europe, Australasia, Asia and south and Central America. In the later 1960s psychedelic scenes developed in a large number of countries in continental Europe, including the Netherlands with bands like The Outsiders, Denmark where it was pioneered by Steppeulvene, Yugoslavia, with bands like Kameleoni, Dogovor iz 1804., Pop Mašina and Igra Staklenih Perli, and Germany, where musicians began to fuse music of psychedelia and the electronic avant-garde. 1968 saw the first major German rock festival, the Internationale Essener Songtage in Essen, and the foundation of the Zodiak Free Arts Lab in Berlin by Hans-Joachim Roedelius, and Conrad Schnitzler, which helped bands like Tangerine Dream and Amon Düül achieve cult status.A thriving psychedelic music scene in Cambodia, influenced by psychedelic rock and soul broadcast by US forces radio in Vietnam, was pioneered by artists such as Sinn Sisamouth and Ros Serey Sothea. In South Korea, Shin Jung-Hyeon, often considered the godfather of Korean rock, played psychedelic-influenced music for the American soldiers stationed in the country. Following Shin Jung-Hyeon, the band San Ul Lim (Mountain Echo) often combined psychedelic rock with a more folk sound. In Turkey, Anatolian rock artist Erkin Koray blended classic Turkish music and Middle Eastern themes into his psychedelic-driven rock, helping to found the Turkish rock scene with artists such as Cem Karaca, Mogollar, Barış Manço and Erkin Koray. In Brazil, the Tropicalia movement merged Brazilian and African rhythms with psychedelic rock. Musicians who were part of the movement include Caetano Veloso, Gilberto Gil, Os Mutantes, Gal Costa, Tom Zé, and the poet/lyricist Torquato Neto, all of whom participated in the 1968 album Tropicália: ou Panis et Circencis, which served as a musical manifesto.
Original psychedelic era:
1969–71: Decline By the end of the 1960s, psychedelic rock was in retreat. Psychedelic trends climaxed in the 1969 Woodstock festival, which saw performances by most of the major psychedelic acts, including Jimi Hendrix, Jefferson Airplane, and the Grateful Dead. LSD had been made illegal in the UK in September 1966 and in California in October; by 1967, it was outlawed throughout the United States. In 1969, the murders of Sharon Tate and Leno and Rosemary LaBianca by Charles Manson and his cult of followers, claiming to have been inspired by Beatles' songs such as "Helter Skelter", has been seen as contributing to an anti-hippie backlash. At the end of the same year, the Altamont Free Concert in California, headlined by the Rolling Stones, became notorious for the fatal stabbing of black teenager Meredith Hunter by Hells Angel security guards.George Clinton's ensembles Funkadelic and Parliament and their various spin-offs took psychedelia and funk to create their own unique style, producing over forty singles, including three in the US top ten, and three platinum albums.Brian Wilson of the Beach Boys, Brian Jones of the Rolling Stones, Peter Green and Danny Kirwan of Fleetwood Mac and Syd Barrett of Pink Floyd were early "acid casualties", helping to shift the focus of the respective bands of which they had been leading figures. Some groups, such as the Jimi Hendrix Experience and Cream, broke up. Hendrix died in London in September 1970, shortly after recording Band of Gypsys (1970), Janis Joplin died of a heroin overdose in October 1970 and they were closely followed by Jim Morrison of the Doors, who died in Paris in July 1971. By this point, many surviving acts had moved away from psychedelia into either more back-to-basics "roots rock", traditional-based, pastoral or whimsical folk, the wider experimentation of progressive rock, or riff-based heavy rock.
Revivals and successors:
Psychedelic soul Following the lead of Hendrix in rock, psychedelia began to influence African American musicians, particularly the stars of the Motown label. This psychedelic soul was influenced by the civil rights movement, giving it a darker and more political edge than much psychedelic rock. Building on the funk sound of James Brown, it was pioneered from about 1968 by Sly and the Family Stone and The Temptations. Acts that followed them into this territory included Edwin Starr and the Undisputed Truth. George Clinton's interdependent Funkadelic and Parliament ensembles and their various spin-offs took the genre to its most extreme lengths making funk almost a religion in the 1970s, producing over forty singles, including three in the US top ten, and three platinum albums.While psychedelic rock began to waver at the end of the 1960s, psychedelic soul continued into the 1970s, peaking in popularity in the early years of the decade, and only disappearing in the late 1970s as tastes began to change. Songwriter Norman Whitfield wrote psychedelic soul songs for The Temptations and Marvin Gaye.
Revivals and successors:
Prog, heavy metal, and krautrock Many of the British musicians and bands that had embraced psychedelia went on to create progressive rock in the 1970s, including Pink Floyd, Soft Machine and members of Yes. The Moody Blues album In Search of the Lost Chord (1968) which is steeped in psychedelia, including prominent use of Indian instruments, is noted as an early predecessor and influence on the emerging progressive movement. King Crimson's album In the Court of the Crimson King (1969) has been seen as an important link between psychedelia and progressive rock. While bands such as Hawkwind maintained an explicitly psychedelic course into the 1970s, most dropped the psychedelic elements in favour of wider experimentation. The incorporation of jazz into the music of bands like Soft Machine and Can also contributed to the development of the jazz rock of bands like Colosseum. As they moved away from their psychedelic roots and placed increasing emphasis on electronic experimentation, German bands like Kraftwerk, Tangerine Dream, Can, Neu! and Faust developed a distinctive brand of electronic rock, known as kosmische musik, or in the British press as "Kraut rock". The adoption of electronic synthesisers, pioneered by Popol Vuh from 1970, together with the work of figures like Brian Eno (for a time the keyboard player with Roxy Music), would be a major influence on subsequent electronic rock.Psychedelic rock, with its distorted guitar sound, extended solos and adventurous compositions, has been seen as an important bridge between blues-oriented rock and later heavy metal. American bands whose loud, repetitive psychedelic rock emerged as early heavy metal included the Amboy Dukes and Steppenwolf. From England, two former guitarists with the Yardbirds, Jeff Beck and Jimmy Page, moved on to form key acts in the genre, The Jeff Beck Group and Led Zeppelin respectively. Other major pioneers of the genre had begun as blues-based psychedelic bands, including Black Sabbath, Deep Purple, Judas Priest and UFO. Psychedelic music also contributed to the origins of glam rock, with Marc Bolan changing his psychedelic folk duo into rock band T. Rex and becoming the first glam rock star from 1970. From 1971 David Bowie moved on from his early psychedelic work to develop his Ziggy Stardust persona, incorporating elements of professional make up, mime and performance into his act.The jam band movement, which began in the late 1980s, was influenced by the Grateful Dead's improvisational and psychedelic musical style. The Vermont band Phish developed a sizable and devoted fan following during the 1990s, and were described as "heirs" to the Grateful Dead after the death of Jerry Garcia in 1995.Emerging in the 1990s, stoner rock combined elements of psychedelic rock and doom metal. Typically using a slow-to-mid tempo and featuring low-tuned guitars in a bass-heavy sound, with melodic vocals, and 'retro' production, it was pioneered by the Californian bands Kyuss and Sleep. Modern festivals focusing on psychedelic music include Austin Psych Fest in Texas, founded in 2008, Liverpool Psych Fest, and Desert Daze in Southern California.
Revivals and successors:
Neo-psychedelia There were occasional mainstream acts that dabbled in neo-psychedelia, a style of music which emerged in late 1970s post-punk circles. Although it has mainly been an influence on alternative and indie rock bands, neo-psychedelia sometimes updated the approach of 1960s psychedelic rock. Neo-psychedelia may include forays into psychedelic pop, jangly guitar rock, heavily distorted free-form jams, or recording experiments. Some of the scene's bands, including the Soft Boys, the Teardrop Explodes, Wah!, Echo & the Bunnymen, became major figures of neo-psychedelia. In the US in the early 1980s it was joined by the Paisley Underground movement, based in Los Angeles and fronted by acts such as Dream Syndicate, the Bangles and Rain Parade.
Revivals and successors:
In the late 80s in the UK the genre of Madchester emerged in the Manchester area, in which artists merged alternative rock with acid house and dance culture as well as other sources, including psychedelic music and 1960s pop. The label was popularised by the British music press in the early 1990s. Erchard talks about it as being part of a "thread of 80s psychedelic rock" and lists as main bands in it the Stone Roses, Happy Mondays and Inspiral Carpets. The rave-influenced scene is widely seen as heavily influenced by drugs, especially ecstasy (MDMA), and it is seen by Erchard as central to a wider phenomenon of what he calls a "rock rave crossover" in the late 80s and early 90s UK indie scene which also included the Screamadelica album by Scottish band Primal Scream.Later according to Treblezine's Jeff Telrich: "Primal Scream made [neo-psychedelia] dancefloor ready. The Flaming Lips and Spiritualized took it to orchestral realms. And Animal Collective—well, they kinda did their own thing." | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**Glossary of chemistry terms**
Glossary of chemistry terms:
This glossary of chemistry terms is a list of terms and definitions relevant to chemistry, including chemical laws, diagrams and formulae, laboratory tools, glassware, and equipment. Chemistry is a physical science concerned with the composition, structure, and properties of matter, as well as the changes it undergoes during chemical reactions; it features an extensive vocabulary and a significant amount of jargon.
Glossary of chemistry terms:
Note: All periodic table references refer to the IUPAC Style of the Periodic Table.
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absolute zero A theoretical condition concerning a system at the lowest limit of the thermodynamic temperature scale, or zero kelvins, at which the system does not emit or absorb energy (i.e. all atoms are at rest). By extrapolating the ideal gas law, the internationally agreed-upon value for absolute zero has been determined as −273.15 °C (−459.67 °F; 0.00 K).
absorbance absorption 1. The physical or chemical process by which a substance in one state becomes incorporated into and retained by another substance of a different state. Absorption differs from adsorption in that the first substance permeates the entire bulk of the second substance, rather than just adhering to the surface.
2. The process by which matter (typically electrons bound in atoms) takes up the energy of electromagnetic radiation and transforms it into any of various types of internal energy, such as thermal energy. This type of absorption is the principle on which spectrophotometry is based.
abundance accuracy How close a measured value is to the actual or true value. Compare precision.
achiral (of a molecule) Having the geometric symmetry of being indistinguishable from its own mirror image; lacking chirality.
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acid 1. (Brønsted–Lowry acid) Any chemical species or molecular entity that acts as a proton donor when reacting with another species, because it loses at least one proton (H+) which is then transferred or 'donated' to the other species, which by definition is a Brønsted–Lowry base. When dissolved in an aqueous solution, a proton donor which increases the concentration of hydronium ion (H3O+) by transferring protons to water molecules may also be called an Arrhenius acid. The term "acid", when not otherwise qualified, often refers implicitly to a Brønsted–Lowry acid.
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2. (Lewis acid) Any chemical species or molecular entity that acts as an electron pair acceptor when reacting with another species, forming a covalent bond by accepting a lone pair of electrons donated by the other species, which is known as a Lewis base. This definition was intended as a generalization of the Brønsted–Lowry definition by proposing that acid-base reactions are best viewed as reorganizations of electrons rather than transfers of protons, with the acid being a species that accepts electron pairs from another species either directly or by releasing protons (H+) into the solution, which then accept electron pairs from the other species. The Lewis definition is inclusive of many Brønsted–Lowry acids, though not all: most Lewis acids are not Brønsted–Lowry acids, and most Brønsted–Lowry acids are not Lewis acids.
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3. Colloquially, any compound which, when dissolved in water, yields a pH of less than 7.0. The term "acid" is commonly used to refer to the entire aqueous solution, whereas stricter definitions refer only to the acidic solute.
acid anhydride Any chemical compound derived by the removal of water molecules from an acid. Contrast base anhydride.
acid dissociation constant (Ka) Also acid ionization constant or acidity constant.
A quantitative measure of the strength of an acid in solution expressed as an equilibrium constant for a chemical dissociation reaction in the context of acid-base reactions. It is often given as its base-10 cologarithm, pKa.
acid–base extraction A chemical reaction in which chemical species are separated from other acids and bases.
actinides Also actinoids.
The periodic series of metallic elements with atomic numbers 89 to 103, from actinium through lawrencium.
activated complex A structure that forms because of a collision between molecules while new bonds are formed.
activation energy The minimum energy which must be available to a chemical system with potential reactants in order to result in a particular chemical reaction.
activity series See reactivity series.
actual yield acyclic Containing only linear structures of atoms (particularly in hydrocarbons).
addition reaction In organic chemistry, a type of chemical reaction in which two or more molecules combine to make a larger one.
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adduct A distinct chemical species that is the sole product of an addition reaction between two other distinct reactant species, in which all of the atoms comprising the reactants are retained in the single product. Changes in connectivity may occur, but there is no loss of any of the original atoms and no gain of atoms that are not present in the reactant molecules. Stoichiometries other than 1:1 are also possible, e.g. a bis-adduct (2:1).
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adhesion The tendency of dissimilar particles or surfaces to cling to one another as a result of intermolecular forces. Contrast cohesion.
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adsorption The chemical adhesion of atoms, ions, or molecules of one substance (either a gas, liquid, or dissolved solid) to the surface of another substance, resulting in a film of the first substance being weakly bonded to the interface between the two substances. Adsorption differs from absorption in that it is exclusively a surface phenomenon, while absorption involves entire volumes of materials.
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aeration The mixing of air into a liquid or a solid.
alcohol Any organic compound consisting of at least one hydroxyl group attached to a saturated carbon atom.
aldehyde A functional group and a class of organic compounds consisting of a carbonyl group attached to a hydrogen atom and any other R-group. Aldehydes have the general formula R–C(H)=O.
aliphatic alkali metal Any of the metallic elements belonging to Group 1 of the periodic table: lithium (Li), sodium (Na), potassium (K), rubidium (Rb), caesium (Cs), and francium (Fr).
alkaline earth metal Any of the metallic elements belonging to Group 2 of the periodic table: beryllium (Be), magnesium (Mg), calcium (Ca), strontium (Sr), barium (Ba), and radium (Ra).
alkane Also paraffin.
Any fully saturated acyclic hydrocarbon, i.e. one in which all carbon–carbon bonds are single bonds.
alkene Also olefin.
Any unsaturated hydrocarbon containing at least one carbon–carbon double bond.
alkyl group The substituent form of an alkane, i.e. any alkane missing a hydrogen atom. The term may be used to refer to many different functional groups, e.g. a methyl or ethyl group.
alkyne Also acetylene.
Any unsaturated hydrocarbon containing at least one carbon–carbon triple bond.
allomer A substance that differs in chemical composition but has the same crystalline structure as another substance.
allotrope Any of a variety of different structural forms of the same element, as with carbon, whose allotropes include diamonds, graphite, and fullerene.
alloy A mixture of metals or of a metal and another element which in combination exhibit a metallic bonding character. Common examples include bronze, brass, and pewter.
amalgam Any alloy of mercury with another metal.
ambident A molecule or functional group that has two alternative and interacting reaction sites, to either of which a bond may be made during a reaction.
ammoniacal Describing a solution in which the solvent is aqueous ammonia.
amount of substance Also enplethy, chemical amount, or simply amount.
The number of discrete particles (such as molecules, atoms, ions, electrons, or any other atomic-scale entity) in a given sample of matter, divided by the Avogadro constant. The SI unit for amount of substance is the mole (mol).
amphoteric Also amphiprotic.
(of a chemical species) Tending to behave both as an acid and as a base, depending upon the medium in which the species is situated; e.g. sulfuric acid (H2SO4) is a strong acid in water but behaves more like a base in superacids.
amphipathic (of a molecule) Composed of both hydrophilic and hydrophobic groups; e.g. wetting agents and membrane lipids.
amyl A common non-systematic name for a pentyl group.
analyte The specific substance or chemical constituent that is of interest in a chemical analysis.
analytical chemistry The branch of chemistry which studies and makes use of instruments and methods to separate, quantify, and identify chemical substances, both by classical wet chemistry techniques such as precipitation, extraction, distillation, and observational analysis, and by modern instrumental techniques such as chromatography, spectroscopy, and electrochemistry.
anhydrous Having or containing no water molecules, referring especially to water of hydration. Because many processes in chemistry are impeded in the presence of water, it is often of critical importance that water-free reagents and techniques are used. Anhydrous compounds tend to gradually absorb water from the atmosphere. Contrast hydrous.
anion A negatively charged ion; i.e. an atom or molecule with a net negative electric charge caused by an excess of electrons compared to protons.
anode 1. An electrode through which the conventional electric current (the flow of positive charges) enters into a polarized electrical circuit.
2. The wire or plate of an electrochemical cell having an excess positive charge. Negatively charged anions always move toward the anode. Contrast cathode.
anomer Either of a pair of cyclic hemiacetal or hemiketal saccharides that are epimers of each other, differing at only one carbon stereocenter, specifically the carbon that bears the aldehyde or ketone functional group in the compound's acyclic, open-chain configuration, known as the anomeric carbon.
aqua regia A liquid mixture of nitric acid (HNO3) and hydrochloric acid (HCl), optimally in a molar ratio of 1:3, so named by historical alchemists because it is capable of dissolving the noble metals gold and platinum.
aquation The process by which water molecules solvate or form coordination complexes with ions.
aqueous solution A solution in which the solvent is water. It is denoted in chemical equations by appending (aq) to a chemical formula.
aromatic aromaticity A chemical property of conjugated rings of atoms, such as benzene, which results in unusually high stability. Such rings are said to be aromatic.
Arrhenius acid Any substance that, when dissolved in water, increases the concentration of H+ ions, or, more correctly, of hydronium ions (H3O+), in the resulting aqueous solution. The definition is similar to that of a Brønsted–Lowry acid. Contrast Arrhenius base.
Arrhenius base Any substance that, when dissolved in water, increases the concentration of OH− ions, or, alternatively, decreases the concentration of hydronium ions (H3O+), in the resulting aqueous solution. The definition is similar to that of a Brønsted–Lowry base. Contrast Arrhenius acid.
arrow pushing aryl Any functional group or substituent derived from an aromatic ring, such as phenyl or naphthyl. The symbol Ar is often used as a placeholder for a generic aryl group in structural diagrams.
atmolysis The separation of a mixture of gases by exploiting their different rates of diffusion, usually by allowing the gases to diffuse through the walls of a porous partition or membrane.
atom A chemical element in its smallest form, made up of protons and neutrons within the nucleus and electrons circling the nucleus.
atomic mass The mass of an atom, typically expressed in daltons and nearly equivalent to the mass number multiplied by one dalton.
atomic mass unit See dalton.
atomic number (Z) Also proton number.
The number of protons found in the nucleus of an atom of a given chemical element. It is identical to the charge number of the nucleus and is used in the periodic table to uniquely identify each chemical element.
atomic orbital Any region in which one or more electrons may be found in an individual atom (as opposed to that within a molecule).
atomic radius atomic weight See relative atomic mass.
atomicity The total number of atoms present in a single molecule of a given substance; e.g. ozone (O3) has an atomicity of 3, while benzene (C6H6) has an atomicity of 12.
autoignition temperature Also kindling point.
The lowest temperature at which a given substance will spontaneously ignite in a normal atmosphere without an external source of ignition such as a flame or spark, i.e. when the ambient temperature is sufficiently high to provide the activation energy needed for combustion. Substances which spontaneously ignite at naturally occurring temperatures are termed pyrophoric. Compare ignition temperature.
Avogadro's law Avogadro constant (NA) The ratio of the number of discrete constituent particles (such as molecules, atoms, or ions) to the amount of a substance, defined as exactly 6.02214076×1023 mol−1.
Avogadro number The number of discrete constituent particles in one mole of a substance, defined as exactly 6.02214076×1023. This dimensionless number differs from the Avogadro constant in that it has no unit.
azeotrope A mixture of liquids whose chemical composition is unchanged by distillation.
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barometer A device used to measure atmospheric pressure.
base A substance that accepts a proton and has a pH above 7.0. A common example is sodium hydroxide (NaOH).
base anhydride An oxide of a group I or II metal element.
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beaker A cylindrical vessel or container with a flat bottom, most commonly a type of glassware, widely used in laboratories for a variety of purposes, such as preparing, holding, containing, collecting, or volumetrically measuring chemicals, samples, or solutions, or as a chamber in which a chemical reaction occurs. Beakers are distinguished from flasks by having straight rather than sloping sides; most beakers also have a small spout in the rim to aid pouring.
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Beer–Lambert law biochemistry The study of the chemistry of biological systems and organisms.
Bohr model Also Rutherford–Bohr model.
A model of the general structure of the atom proposed by Niels Bohr and Ernest Rutherford in 1913, featuring a small, dense nucleus of positively charged particles surrounded by orbiting electrons, which are attracted to the nucleus by electrostatic forces. This interpretation replaced several earlier hypotheses and quickly became the prevailing standard model for depicting atomic structure.
boiling See vaporization.
boiling point Also vaporization point.
The temperature at which a substance changes state from a liquid to a gas (or vapor). It depends on pressure and is usually specified for a given substance under standard conditions.
boiling-point elevation The process by which a substance's boiling point is elevated by adding another substance.
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bond Any persistent attraction between atoms, ions, or molecules that enables the formation of chemical compounds. Bonds are created as a result of a wide variety of electrochemical forces, whose strengths can vary considerably; they are broken when these forces are overcome by other forces. The types, strengths, and quantities of bonds holding together chemical substances dictate the structure and bulk properties of matter.
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Boyle's law For a given mass of gas at constant temperature, the volume varies inversely with the pressure.
Bragg's law Brønsted–Lowry acid Any chemical species that readily donates a proton.
Brønsted–Lowry acid–base reaction Brønsted–Lowry base Any chemical species that readily accepts a proton.
Brownian motion Büchner flask buffered solution Also simply called a buffer.
An aqueous solution consisting of a weak acid and its conjugate base or a weak base and its conjugate acid that resists changes in pH when strong acids or bases are added.
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bumping A phenomenon in which a homogeneous liquid raised to its boiling point becomes superheated and, upon nucleation, rapidly boils to the gas phase, resulting in a violent expulsion of the liquid from the container; in extreme cases, the container itself may shatter. Frequent stirring, the use of an appropriate container, and the use of boiling chips can help prevent bumping.
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bung burette Also spelled buret.
Glassware used to dispense specific amounts of liquid when precision is necessary (e.g. during titrations and resource-dependent reactions).
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calorific value A measure of the heat per unit mass produced by complete combustion of a given substance, usually expressed in megajoules per kilogram (MJ/kg) or in kilojoules per gram (kJ/g).
calorimeter Any of various devices used to measure thermal properties (i.e. heat), such as calorific values or heats of chemical reactions.
calx A metal oxide formed by heating an ore in air.
carbanion carbocation carbonyl 1. A functional group composed of a carbon atom double-bonded to an oxygen atom, with the formula C=O . Carbonyl groups are common to many classes of organic compounds and are also a part of many larger functional groups.
2. An inorganic or organometallic coordination complex with carbon monoxide as a ligand (e.g. a metal carbonyl).
carboxylic acid A class of organic acids and a functional group consisting of a carboxyl group attached to a substituent group. Carboxylic acids have the general formula COOH (also written as CO 2H ), where R can be an alkyl, alkenyl, aryl, or any other carbon-containing substituent.
CAS Registry Number (CAS RN) Also simply CAS Number.
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A unique numerical identifier assigned by the Chemical Abstracts Service (CAS) to every chemical substance described in the open scientific literature, including more than 182 million organic and inorganic compounds, minerals, isotopes, alloys, polymers, and mixtures, as well as so-called "UVCBs" (substances of unknown or variable composition, complex reaction products, or biological origin). CAS numbers are an internationally recognized standard used by scientists, industries, and regulatory bodies.
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catalyst Any element or compound that facilitates an increase in the speed of a chemical reaction but which is not consumed or destroyed during the reaction. It is considered both a reactant and a product of the reaction.
cathode An electrode from which the conventional electric current (the flow of positive charges) exits a polarized electrical circuit. Positively charged cations always move toward the cathode, though the cathode's polarity can be positive or negative depending on the type of electrical device and how it is being operated. Contrast anode.
cation A positively charged ion.
cell potential The force in a galvanic cell that pulls electrons through a reducing agent to an oxidizing agent.
centrifugation A laboratory technique which involves the application of centrifugal force to separate particles from a solution according to their size, shape, and density. Larger and/or denser substances migrate away from the axis of a centrifuge, while smaller and/or less dense substances migrate towards the axis.
centrifuge A device used to separate substances based on size, shape, and density by centrifugation, or the rotation of vessels containing the substances around a centred axis at extremely high velocities.
chain reaction charge number A quantized value of electric charge calculated as the electric charge in coulombs divided by the elementary-charge constant, or z = q/e. Charge numbers for ions are denoted in superscript (e.g. Na+ indicates a sodium ion with a charge number of positive one). Atomic numbers are charge numbers of atomic nuclei.
Charles's law When the pressure on a sample of a dry gas is held constant, the Kelvin temperature is directly proportional to its volume.
chelating agent chelation A type of bonding involving the formation of two separate coordinate covalent bonds between a polydentate ligand and a single central metal ion. The ligand is usually an organic compound called a chelant or chelating agent.
chemical composition The identity and relative number of the elements that make up a chemical compound, which can often be expressed with a chemical formula.
chemical decomposition The breakdown of a single particle or entity (such as a molecule or reactive intermediate) into two or more fragments, or a chemical reaction in which two or more products are formed from a single reactant. Contrast chemical synthesis.
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chemical formula Any of various means of concisely displaying information about the chemical composition of a compound or molecule using letters, numbers, and/or typographical symbols. Chemical formulas, such as empirical and molecular formulas, can only indicate the identities and numerical proportions of the atoms in a compound and are therefore more limited in descriptive power than chemical names and structural formulas.
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chemical law A law of nature relevant to chemistry, such as the law of conservation of mass.
chemical nomenclature chemical process 1. Any method or means of changing one or more chemicals or chemical compounds in any way, either naturally or artificially, spontaneously or by the actions of external forces.
2. In chemical engineering, any method used on an industrial scale (especially in manufacturing) to change the composition of one or more chemicals or materials.
chemical reaction The change of one or more substances into one or more different substances.
chemical species Also simply called a chemical.
A chemical substance or ensemble of substances composed of chemically identical molecular entities which can explore the same set of molecular energy levels on a characteristic or delineated time scale.
chemical substance Also pure substance or simply substance.
A form of matter that has constant chemical composition and characteristic properties and which cannot be separated into simpler components by purely physical methods (i.e. without breaking chemical bonds). It is often called a pure substance to distinguish it from a mixture.
chemical synthesis The artificial execution of one or more chemical reactions in order to obtain one or more products. In modern laboratory contexts, specific chemical syntheses are both reliable and reproducible.
chemistry The scientific discipline that studies chemical substances, compounds, and molecules composed of atoms of various chemical elements, as well as their compositions, structures, properties, behaviors, and the changes they undergo during reactions with other substances.
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chirality A property of asymmetry in which a molecule or ion is distinguishable from its mirror image such that it cannot be superposed upon it by any combination of geometric rotations, translations, or some conformational changes. Such a molecule or ion is said to be chiral, and exists in two forms, known as enantiomers, which are stereoisomers of each other; these forms are distinguished as either "right-handed" or "left-handed" by their absolute configuration or some other criterion. Several different types of asymmetry can give rise to chirality, most commonly when molecules possess stereogenic elements such as one or more stereocenters (central chirality), a stereogenic axis (axial chirality), or a stereogenic plane (planar chirality); additionally, the inherent curvature of a molecule can cause it to possess inherent chirality.
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chromatography cis–trans isomerism closed system cluster cohesion The tendency of similar particles or surfaces to cling to one another as a result of intermolecular forces. Contrast adhesion.
colligative property Any property of a solution that depends upon the ratio of the number of solute particles to the number of solvent particles in the solution, and not on the nature of the chemical species present. Examples include osmotic pressure, freezing-point depression, and boiling-point elevation.
colloid A mixture of evenly dispersed substances, such as many milks.
color standard A liquid solution of known chemical composition and concentration, and hence of known and standardized color, used as a reference in the optical analysis of samples of unknown strength.
color test The quantitative analysis of a substance by comparing the intensity of the color produced when the substance is exposed to a reagent with a standard color produced similarly in a solution of known strength.
colorimeter Also chromometer.
Any instrument used for color measurement based on optical comparison with standard colors, particularly a device used in colorimetry that measures the absorbance of specific wavelengths of light by a given solution in order to determine the concentration of a known solute in the solution, by application of the principle that solute concentration is directly proportional to absorbance.
combustion An exothermic reaction between an oxidant and a fuel that produces large amounts of heat and often light.
Commission on Isotopic Abundances and Atomic Weights (CIAAW) complex A molecular entity formed by loose association between two or more component molecular entities (ionic or uncharged), or the corresponding chemical species. The bonding between the components is normally weaker than in a covalent bond. See also coordination complex.
compound A substance that is made up of two or more chemically bonded elements.
Compton rule An empirical law of physical chemistry which states that the heat of fusion of a given element multiplied by its atomic weight and then divided by its melting point in kelvin is always equal to approximately 2.
concentration The quantity or abundance of a constituent of a mixture per unit quantity of the mixture; e.g. the amount of a dissolved solute per unit volume of the solution, a measure known as molarity. Several different definitions of concentration are widely used in chemistry, including mass concentration, volume concentration, and molar concentration.
condensation The phase transition of a substance from a gas to a liquid.
condosity A comparative measurement of the electrical conductivity of a solution defined as the molar concentration of a sodium chloride (NaCl) solution that has the same specific electrical conductance as the solution under test. It is typically expressed in units of moles per litre (or per some other unit of volume).
conductor Any object or material that allows the flow of an electric current in one or more directions. Contrast insulator.
conformation The spatial arrangement of atoms affording distinction between stereoisomers which can be interconverted by rotations about formally single bonds.
conjugate acid conjugate base conjugated system A molecule that contains double or triple bonds separated by one single bond; e.g. the compound buta-1,3-diene, with the chemical structure H2C=CH−CH=CH2, has conjugated double bonds. In such molecules, there is some delocalization of electrons in the pi orbitals between the carbon atoms linked by the single bond.
constitutional isomer See structural isomer.
cooling curve coordinate chemistry coordinate covalent bond See dipolar bond.
coordination complex A chemical compound consisting of a central atom or ion, usually metallic and known as the coordination center, bonded to a surrounding array of other groups of atoms, e.g. molecules or ions, which are known as ligands or complexing agents. Many metal-containing compounds, especially those of the transition metals, are coordination complexes. See also complex.
corrosion An irreversible interfacial chemical reaction of a material, especially a metal, with its environment, which results in consumption of the material or dissolution into the material of an external component of the environment.
coulomb The SI unit of electric charge (symbol: C), defined as the charge transported by a constant current of one ampere in one second.
counterion The ion that is the counterpart to an oppositely charged ion in a dissociated ionic species; the cation that pairs with a given anion, or vice versa. For example, Na+ is the counterion to Cl−, and vice versa, in solutions of sodium chloride (NaCl).
covalent bond Also molecular bond.
A bond that involves the sharing of electron pairs between atoms. The stable balance of attractive and repulsive forces that occurs between atoms when they share electrons is known as covalent bonding.
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critical point The end point of a phase equilibrium curve or pressure-temperature curve at which conditions are such that phase boundaries vanish and a substance's different phases, such as liquid and vapor, can coexist. The critical point is defined by the intersection of a critical temperature, Tc, and a critical pressure, pc; above this temperature and pressure, all distinction between phases disappears and the substance becomes a supercritical fluid.
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crucible A ceramic or metal dish or other vessel in which substances can be melted or otherwise subjected to very high temperatures.
crystal A solid whose constituent particles (such as atoms, ions, or molecules) are arranged in an orderly periodic microscopic structure, forming a lattice that extends in all directions. Such materials are often described as crystalline.
crystallization point See freezing point.
crystallography The branch of chemistry concerned with determining the arrangement of atoms within crystalline solids.
cuvette A type of glassware used in spectroscopic experiments. It is usually made of plastic, glass, or quartz and should be as clean and clear as possible.
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d-block dalton (Da) Also unified atomic mass unit (u).
{{defn|A unit of mass defined as 1⁄12 of the mass of a free unexcited atom of carbon-12 at rest. It is approximately equal to the mass of one nucleon.
Dalton's law of partial pressures An empirical law which states that in a mixture of non-reacting gases, the total pressure exerted by all of the gases combined is equal to the sum of the partial pressures exerted by each gas individually.
dative bond See dipolar bond.
debye (D) A non-SI unit of measurement of electric dipole moment, defined as 10−18 statcoulomb-centimetres. See also electric dipole moment.
deionization The removal of ions from a solution by any method. In the case of water, this typically refers to mineral ions such as sodium, iron, and calcium.
deliquescence A substance's affinity for water, often characterized as its tendency to absorb moisture from the atmosphere to form aqueous solutions. Most strongly deliquescent substances are salts, such as calcium chloride and potassium carbonate.
delocalized electron Any electron in a molecule, ion, or solid metal that is not associated with an individual atom or covalent bond. The term may refer to electrons involved in resonance in conjugated systems or aromatic compounds; to free electrons which facilitate electrical conductivity; or to electrons within delocalized molecular orbitals encompassing several adjacent atoms.
density An intensive property of a substance defined as mass per unit volume and expressed by the equation d = m/V.
denticity The number of donor groups in a single ligand that bind to a central atom in a coordination complex.
dependent variable deposition The settling of particles within a solution or mixture.
desiccant Also drying agent.
A hygroscopic substance used to induce or sustain a state of dryness or desiccation (i.e. the absence of moisture) in its vicinity by abstracting water molecules from other substances. Desiccants come in many different forms and work by many different principles, ranging from simple absorption to the chemical bonding of water molecules.
Dewar flask See vacuum flask.
diatomic Composed of two atoms, of the same or different elements. Contrast monatomic and polyatomic.
diatomic molecule Any molecule composed of only two atoms, of the same or different elements.
diffusion The net movement of atoms or molecules from a region of higher concentration to a region of lower concentration. Diffusion is driven by a gradient in chemical potential of the diffusing species and depends on the random walk of particles; hence it results in mixing or mass transport without required directed bulk motion.
dilatant A substance with the ability to increase in volume when its shape is changed.
dilution dimer An oligomer consisting of two monomers joined by chemical bonds that may variably be strong or weak, covalent or intermolecular. A homodimer consists of two identical molecules; a heterodimer consists of two different molecules.
dipolar bond Also coordinate covalent bond, coordinate bond, dative bond, and semipolar bond.
A type of covalent bond formed by the coordination of two or more electrically neutral moieties, the combination of which results in a charge-separated molecule or coordination complex, in which two electrons deriving from the same atom are shared between the donor atom and an acceptor atom, creating an internal two-center molecular dipole moment.
dipole The electric or magnetic separation of electric charge into a pair of charges of equal magnitude but opposite sign, one positively charged and one negatively charged, separated by some typically small distance.
dipole moment See electric dipole moment, magnetic dipole moment, molecular dipole moment, bond dipole moment, electron electric dipole moment, electron magnetic dipole moment, and nuclear magnetic moment.
diastereomer dispersion A system in which particles of one material are distributed within a continuous phase of another material; the two phases may be in the same or different states of matter. Dispersions of particles sufficiently large for sedimentation are called suspensions, while those of smaller particles are called colloids or solutions.
dissociation Any process by which a polyatomic molecule or molecular entity (e.g. an ionic compound or coordination complex), or an aggregate of molecular entities, separates or splits into two or more molecules, atoms, ions, radicals, or other constituents, usually in a reversible manner. Examples include unimolecular heterolysis and homolysis, the dissolution of salts, and acid dissociation. Contrast association.
dissolution Also solvation.
The interaction of a solvent with the molecules or ions of a solute, involving bond formation, hydrogen bonding, and van der Waals forces.
distillation The process of separating the component substances of a liquid mixture by exploiting differences in the relative volatility of the mixture's components through selective boiling and subsequent condensation. The apparatus used to distill a substance is called a still, and the re-condensed substance yielded by the process is called the distillate.
double bond A bond involving the covalent sharing of two pairs of electrons.
double decomposition double displacement double salt 1. A salt composed of more than one different cation or anion, or which upon hydrolysis forms two different cations and anions.
2. A salt that is a molecular combination of two other salts.
double-replacement reaction dropping point The temperature at which a grease changes from a semi-solid to a liquid state under standardized conditions, i.e. the upper limit at which the grease retains its structure, though not necessarily the maximum temperature at which it can be used.
dry box A chamber or container in which the interior is maintained at very low humidity, often by filling it with argon or with air lacking carbon dioxide, in order to provide an inert atmosphere in which manipulation of very reactive chemicals or moisture-sensitive procedures can be carried out in the laboratory.
drying agent See desiccant.
ductility Also malleability.
A measure of a material's ability to undergo significant plastic deformation before rupturing, typically expressed as percent elongation or percent area reduction from a tensile test and popularly characterized by the material's ability to be stretched into a wire.
dystectic mixture A mixture of two or more substances which has the highest melting point of all possible mixtures of these substances. Contrast eutectic mixture.
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earth metal See alkaline earth metal.
effective molecular diameter The physical extent of the electron cloud surrounding a molecule of a particular gas, as calculated in any of several ways and usually expressed in nanometres or ångströms.
effervescence The escape of gas from an aqueous solution without the application of heat, and the bubbling, foaming, or fizzing that results; e.g. the release of carbon dioxide from carbonated water.
electric charge A measured property (coulombs) that determines electromagnetic interaction.
electric dipole moment A measure of the separation of positive and negative electric charges within an electrical system, i.e. a measure of the system's overall electrical polarity. The SI unit for measuring electric dipole moment is the coulomb-metre (C⋅m), but the debye (D), a non-SI unit, is also widely used in chemistry and atomic physics.
electride An ionic compound in which the anion is an electron.
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electrochemical cell A device capable of either generating electrical energy from chemical reactions, in which case it is known as a galvanic or voltaic cell, or using electrical energy to cause chemical reactions, in which case it is known as an electrolytic cell. For example, a battery contains one or more galvanic cells, each of which consists of two electrodes arranged such that an oxidation–reduction reaction produces an electromotive force.
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electrochemistry A branch of physical chemistry concerned with the relationship between electrical potential difference and identifiable chemical change, as understood through either the chemical reactions accompanying the passage of an electric current or the potential difference that results from a particular chemical reaction.
electrolyte A solution that conducts a certain amount of electric current and can be split categorically into weak and strong electrolytes.
electromagnetic radiation A type of wave that can go through vacuums as well as material and is classified as a self-propagating wave.
electromagnetic spectrum electromagnetism Fields with an electric charge and electrical properties that change the way that particles move and interact.
electromotive force (emf) electron A type of subatomic particle with a net charge that is negative. Contrast positron.
electron capture A type of nuclear transformation by which the proton-rich nucleus of an electrically neutral atom absorbs or 'captures' an electron from one of its own inner shells, often those closest to the nucleus, which provokes a reaction that results in a nuclear proton changing into a neutron accompanied by the simultaneous emission of an electron neutrino.
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electron configuration The distribution of the electrons of an atom or molecule within atomic or molecular orbitals. An extensive system of notation is used to concisely and uniquely display information about the electron configuration of each atomic species. Knowledge of the specific arrangements of electrons in different atoms is useful for understanding chemical bonds and the organization of the periodic table of the elements.
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electron deficiency electron electric dipole moment (de) An intrinsic property of an electron such that its potential energy is linearly related to the strength of its electric field; a measure of the distribution of an electron's negative charge within the electric field it creates. See also electric dipole moment.
electron magnetic dipole moment Also electron magnetic moment.
The magnetic moment of an electron, caused by the intrinsic properties of its spin and electric charge, equal to approximately −9.284764×10−24 joules per tesla.
electron neutrino electron pair Two electrons which occupy the same molecular orbital but have opposite spins. Electron pairs form chemical bonds or occur as lone pairs of valence electrons; it is also possible for electrons to occur individually as unpaired electrons.
electron shell An orbital around the nucleus of an atom which contains a fixed number of electrons (usually two or eight).
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electronegativity (χ) A chemical property that describes the tendency of an atom to attract a shared pair of electrons (or electron density) towards itself. An atom's electronegativity is affected both by its nuclear charge (which is proportional to the number of protons in its nucleus) and the number and location of the electrons present in its atomic shells (which influences the distance of the nucleus from the valence electrons). The higher an atom or substituent's electronegativity, the more it attracts electrons towards itself. As it is usually calculated, electronegativity is not a property of an atom alone but rather of an atom within a molecule; it therefore varies with an element's chemical environment, though it is generally considered a transferable property.
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electrophile Any atom or molecule which can accept an electron pair. Most electrophiles carry a net positive charge, include an atom carrying a partial positive charge, or include a neutral atom that does not have a complete octet of electrons, and therefore they attract electron-rich regions of other species; an electrophile with vacant orbitals can accept an electron pair donated by a nucleophile, creating a chemical bond between the two species. Because they accept electrons, electrophiles are Lewis acids by definition.
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electrosynthesis element A species of atoms having the same number of protons in their atomic nuclei and hence the same atomic number. Chemical elements constitute all of the ordinary matter in the universe; 118 elements have been identified and are organized by their various chemical properties in the periodic table of the elements.
elementary reaction Any chemical reaction in which one or more chemical species react directly to form products in a single reaction step and with a single transition state, i.e. without any intermediates. Contrast stepwise reaction.
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elution The process of extracting one material from another by washing with a solvent. Elution works by running a solution containing an analyte past an adsorbent matrix designed to selectively bind the analyte molecules, and subsequently washing the adsorbent/analyte complex with a solvent, known as an eluent. The solvent molecules displace the analyte by binding to the adsorbent in its place, allowing the analyte, now part of the eluate, to be carried out of the complex and into a collector for analysis.
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empirical formula The simplest whole-number ratio of the atoms of each element present in a chemical compound.
emulsion A type of colloid in which small particles of one liquid are dispersed in another liquid; e.g. a dispersion of water in an oil, or of an oil in water. Emulsions are often stabilized by the addition of a substance, known as an emulsifier, that has both lyophilic and lyophobic parts in its molecules.
enantiomer enantiomorph endothermic process energy A system's ability to do work.
enplethy See amount of substance.
enthalpy A measure of the total internal energy of a thermodynamic system, usually symbolized by H.
enthalpy of fusion entropy The amount of energy not available for work in a closed thermodynamic system, usually symbolized by S.
environmental chemistry enzyme A biological protein catalyst that speeds up a chemical reaction.
epimer Eppendorf tube A generalized and trademarked name used to refer to a microcentrifuge tube.
equation of state equimolar Having an equal number of moles, or solutions of equal molar concentration.
equilibrium The condition of a system in which all competing influences are balanced. Chemical equilibrium is the state in which the concentrations of the reactants and products in a reacting system have stopped changing in time.
Erlenmeyer flask ester A class of organic and inorganic compounds derived from the reaction of an acid with an alcohol, in which at least one hydroxyl group (–OH) is replaced by an alkoxy group (–O–). Esters have the general formula RCO2R′, where R and R' represent any alkyl or aryl group.
ether A class of organic compounds and a functional group containing an oxygen atom connected to two alkyl or aryl groups, which may be the same or different. Ethers have the general formula R–O–R′, where R and R′ represent the alkyl or aryl groups.
eutectic mixture A solid solution consisting of two or more substances which collectively have the lowest melting point of any possible mixture of these components.
exothermic process extensive property A physical quantity whose value is proportional to the size of the system it describes or to the quantity of matter in the system. Examples include mass, volume, enthalpy, and entropy. Contrast intensive property.
extraction 1. A separation process in which a component is separated from its mixture by selective solubility. See also partition.
2. The separation of a component analyte from a matrix.
extrinsic property
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f-block Faraday constant (F) A unit of electric charge widely used in electrochemistry equal to the negative of the molar charge (electric charge per mole) of electrons. It is equal to approximately 96,500 coulombs per mole (F = 96485.33212... C/mol).
Faraday's laws of electrolysis A set of two laws pertaining to electrolysis which hold that: a) the mass of a substance altered at an electrode during electrolysis is directly proportional to the quantity of electricity transferred at that electrode; and b) the mass of an elemental material altered at an electrode is directly proportional to the element's equivalent weight.
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Fick's laws of diffusion filtration Any physical, biological, or chemical operation that separates large particles (often solid matter) from smaller particles (often a fluid) by passing the mixture through a complex lattice structure through which only particles of a sufficiently small size can pass, called a filter. The fluid and small particles which successfully pass through the filter are called the filtrate.
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fire point The lowest temperature at which the vapors above a volatile material will continue to burn for at least five seconds after ignition by an open flame of standard dimension. The fire point should not be confused with the flash point, a slightly lower temperature at which a substance will ignite briefly but at which vapor is not produced at a rate sufficient for sustained combustion.
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first-order reaction flash point The lowest temperature at which the vapors above a volatile material will ignite if given an ignition source. At the flash point, the application of an open flame causes only a momentary "flash" rather than sustained combustion, for which the ambient temperature is still too low. The flash point should not be confused with the fire point, which occurs at a slightly higher temperature, nor with the kindling point, which is higher still.
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flask A vessel or container, most commonly a type of glassware, widely used in laboratories for a variety of purposes, such as preparing, holding, containing, collecting, or volumetrically measuring chemicals, samples, or solutions, or as a chamber in which a chemical reaction occurs. Flasks come in a number of shapes and sizes but are typically characterized by a wider vessel "body" and one or more narrower tubular sections with an opening at the top.
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flocculation The process by which the dispersed particles in a colloid come out of suspension to aggregate into larger clumps known as floc or flake, either spontaneously or due to the addition of a clarifying agent. The term is often used to refer to a reversible aggregation in which the forces holding the particles together are weak and the colloid can be re-dispersed by agitation.
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formal charge (FC) The electric charge assigned to an atom in a molecule, assuming that all electrons in all bonds are shared equally between atoms, regardless of each atom's relative electronegativity. The formal charge of any atom that is part of a molecule can be calculated by the equation FC=V−N−B2 , where V is the number of valence electrons of the neutral atom in its ground state; N is the number of valence electrons of the atom which are not participating in bonds in the molecule; and B is the number of electrons shared in bonds with other atoms in the molecule.
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formula weight (FW) A synonym for molar mass and molecular weight, frequently used for non-molecular compounds such as ionic salts.
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fraction fractional distillation The fractionation of a mixture of liquids into its component parts, or fractions, by the process of distillation, typically by using a long vertical column attached to the distillation vessel and filled with glass beads. The mixture is heated to a temperature at which one or more of the component compounds will vaporize; the vapor rises up the column until it condenses and runs back into the vessel, creating a temperature and volatility gradient and permitting various fractions to be drawn off at different points along the length of the column. Common in industrial chemistry, the technique is sensitive enough to separate compounds which have boiling points that differ by less than 25 °C (45 °F) from each other at standard pressure.
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fractionation A separation process in which a particular quantity of a mixture is divided during a phase transition into a number of smaller quantities, known as fractions, for which the chemical composition varies according to a gradient. Fractionation exploits subtle differences in some specific property (e.g. mass, boiling point, solubility, etc.) between the mixture's component compounds, making it possible to isolate more than two components of a mixture at the same time. There are many varieties of fractionation employed in many branches of science and technology.
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free radical See radical.
freezing The phase transition of a substance from a liquid to a solid.
freezing point Also crystallization point.
The temperature at which a substance changes state from a liquid to a solid. Because freezing is the reverse of melting, the freezing point of a substance is identical to its melting point, but by convention only the melting point is referred to as a characteristic property of a substance.
freezing-point depression Also depression of freezing point.
frequency A measurement of the number of cycles of a given process per unit of time. The SI unit for measuring frequency is the hertz (Hz), with 1 Hz = 1 cycle per second.
functional group
G:
galvanic cell A type of battery made up of electrochemicals with two different metals connected by a salt bridge.
gas One of the four fundamental states of matter, characterized by high-energy particles which fill their container but have no definite shape or volume.
gas chromatography A type of chromatography commonly used in analytical chemistry to isolate and analyze chemical compounds that can be vaporized without decomposition. Gas chromatography is often used to test the purity of substances, to identify unknown substances, and to measure the relative amounts of the different components of mixtures.
gauche In alkane stereochemistry, a structural conformation involving a torsion angle of ±60°, or a synclinal alignment of functional groups attached to adjacent atoms.
Gay-Lussac's law A chemical law used for each of the two relationships derived by French chemist Joseph Louis Gay-Lussac and which concern the properties of gases, though the name is more usually applied to his law of combining volumes.
geochemistry The study of the chemistry and chemical composition of the Earth and geological processes.
Gibbs energy A value that indicates the spontaneity of a reaction. Usually symbolized as G.
glass glycol Any of a class of aliphatic dihydric alcohols in which the two hydroxy groups are bonded to two different carbon atoms, which are usually but not necessarily adjacent to each other; e.g. ethylene glycol (HOCH2CH2OH).
gram-atom A former term for a mole.
Grignard reaction ground glass joint An apparatus designed to quickly and easily fit two pieces of leak-tight glassware together, featuring ground glass surfaces and typically a custom-made conical taper.
ground state The lowest possible energy state for a given quantum mechanical system, at which the Gibbs energy is actually or theoretically minimized. Whatever energy remains in the system in its ground state is called the zero-point energy. Contrast excited state.
group Also family.
A vertical column of the periodic table of the elements and the elements that share it. Contrast period.
H:
hadron A subatomic particle of a type including the baryons and mesons that can take part in the strong interaction.
halogen Any of the five non-metallic elements of Group 17 of the periodic table: fluorine (F), chlorine (Cl), bromine (Br), iodine (I), and astatine (At).
hard acid A Lewis acid with an electron-accepting centre that is only weakly polarizable. Hard acid species also tend to have high charge states and relatively small atomic nuclei, in contrast to soft acids.
hard water Water that has very high mineral content, generally formed when water percolates through deposits rich in calcium, magnesium, and certain other metal cations.
heat Energy transferred from one system to another by thermal interaction.
heat of fusion See enthalpy of fusion.
Henry's law Hess' law of constant heat summation Also simply called Hess' law.
A law of physical chemistry which states that the total enthalpy change during the course of a chemical reaction is the same whether the reaction is completed in one step or in multiple steps.
Hund's rules hydrate Any substance that contains water or its constituent elements, or any compound formed by the addition of water or its elements to another molecule.
hydration reaction hydrogen hydrogen bond A form of electrostatic interaction between an electronegative atom and a hydrogen atom bound to a second electronegative atom. Hydrogen bonding is unique because the small size of the hydrogen atoms permits proximity of the interacting electrical charges, and may occur as an intermolecular or intramolecular force.
H:
hydrogenation Any chemical reaction between molecular hydrogen (H2) and another chemical species, typically resulting in the reduction or saturation of the other species by the addition of one or more pairs of hydrogen atoms to a compound or element. The presence of a catalyst is usually required for hydrogenation reactions to occur; non-catalytic hydrogenation takes place only at extreme temperatures.
H:
hydrolysis The cleavage of a chemical bond by the addition of water.
hydron (H+) Informally synonymous with proton.
The cationic form of atomic hydrogen; i.e. a positively charged hydrogen nucleus of any isotopic composition. Thus the term can refer to a proton (11H+), deuteron (21H+), or triton (31H+).
hydrous Having or containing water molecules, referring especially to water of hydration. Contrast anhydrous.
hydroxide A diatomic anion consisting of a hydrogen atom covalently bonded to an oxygen atom, having an overall negative charge, with the chemical formula OH−; or any member of a class of organic and inorganic compounds containing a hydroxy group, e.g. sodium hydroxide (NaOH).
hydroxy hygroscopy
I:
ideal gas A hypothetical gas composed of many randomly moving point particles that do not participate in any interparticle interactions, thereby making it mathematically convenient to describe and predict their behavior as state variables change. The ideal gas concept is useful because it obeys the ideal gas law and can be analyzed within the framework of statistical mechanics.
ideal gas constant Also universal gas constant.
The proportionality constant in the ideal gas law, defined as 0.08206 L·atm/(K·mol).
ideal gas law Also general gas equation.
I:
The equation of state of a hypothetical ideal gas, which states that the volume of such a gas is proportional to the amount of gas and its Kelvin temperature, and inversely proportional to its pressure. The ideal gas law combines Boyle's law, Charles's law, Gay-Lussac's law, and Avogadro's law into a single equation, conventionally formulated as PV=nRT , where R is the ideal gas constant. The relationships between the state variables described in this equation are a good approximation of the behavior of many gases under a wide range of conditions, though there are some limitations.
I:
ideal solution A solution for which the gas phase exhibits thermodynamic properties analogous to those of a mixture of ideal gases.
independent variable indicator A special compound added to a solution that changes color depending on the acidity of the solution. Different indicators have different colors and are effective within different pH ranges.
induced radioactivity Radioactivity caused by bombarding a stable isotope with elementary particles, forming an unstable, radioactive isotope.
inert inorganic compound Any chemical compound that does not contain carbon, though there are exceptions. Contrast organic compound.
inorganic chemistry The branch of chemistry concerning the chemical properties and reactions of inorganic compounds. Contrast organic chemistry.
insolubility The inability of a substance (the solute) to form a solution by being dissolved in another substance (the solvent); the opposite of solubility.
inspissation The process of thickening a liquid by any method of dehydration, especially evaporation.
insulator Any material that resists the flow of an electric current. Contrast conductor.
intensive property A physical quantity whose value does not depend on the size of the system or the quantity of matter for which it is measured. Examples include density, temperature, and pressure. Contrast extensive property.
interface The boundary between two spatial regions occupied by different matter, especially by matter in different phases or physical states. See also surface and phase boundary.
intermetallic A type of alloy that forms an ordered solid-state compound between two or more metallic elements. Intermetallics are generally hard and brittle, and have useful mechanical properties at high temperatures.
intermolecular force Any force that mediates interaction between molecules, e.g. electromagnetic forces of attraction or repulsion, hydrogen bonding, and the van der Waals force, all of which act between the atoms of one molecule and the atoms or ions of nearby molecules. Intermolecular forces are weak compared to intramolecular forces such as covalent bonds, which hold individual molecules together.
International System of Units (SI) International Union of Pure and Applied Chemistry (IUPAC) An international federation of chemists that is recognized as the world authority in developing standards for chemical nomenclature and other methodologies in chemistry.
interstitial compound A compound composed of a transition metal bonded to either hydrogen, boron, carbon, or nitrogen, whose crystal structure consists of closely packed metal ions with the non-metal atoms located in the interstices.
intramolecular force intrinsic property ion A molecule that has gained or lost one or more electrons from its neutral state and therefore possesses a negative or positive electric charge.
ionic bond An electrostatic attraction between oppositely charged ions.
ionic strength A measure of the concentration of ions in a solution, usually expressed in terms of molarity (mol/L solution) or molality (mol/kg solvent).
ionization The breaking up of a chemical compound into separate ions.
isoelectronicity The phenomenon of two or more chemical species (atoms, molecules, ions, etc.) being composed of different elements but having the same number of valence electrons and the same structural arrangement (i.e. the same number of atoms with the same connectivity). Isoelectronic species typically show useful consistency and predictability in their chemical properties.
isomerization isomers Ions or molecules with identical chemical formulas but distinct structures or spatial arrangements. Isomers do not necessarily share similar properties. The two main types of isomers are structural isomers and stereoisomers.
isotope A variant of a particular chemical element which differs in the number of neutrons present in the nucleus. All isotopes of a given element have the same number of protons in each atom.
J:
joule (J) The SI unit of energy (symbol: J). One joule is defined as one newton-metre.
K:
kelvin (K) The SI unit of temperature (symbol: K). The Kelvin scale is an absolute thermodynamic temperature scale that uses absolute zero as its null point.
keto acid Also ketoacid.
Any organic compound that can be classified as both a ketone and a carboxylic acid, by virtue of containing a keto group and a carboxyl group.
ketone A class of organic compounds and a functional group composed of a carbonyl group between two carbon atoms. Ketones have the general formula R2C=O, where R can be any carbon-containing substituent.
kindling point See autoignition temperature.
kinetics A subfield of chemistry specializing in reaction rates.
kinetic energy The energy of an object due to its motion.
L:
lability lanthanides Also lanthanoids.
The periodic series of metallic elements with atomic numbers 57 through 71, from lanthanum through lutetium.
lattice The unique arrangement of atoms or molecules in a crystalline liquid or solid.
L:
lattice energy The energy released upon the formation of one mole of a crystalline ionic compound from its constituent ions, which are assumed to exist initially in the gaseous state. Lattice energy can be viewed as a measure of the cohesive forces that bind ionic solids; it is therefore directly related to many other physical properties of the solid, including solubility, hardness, and volatility.
L:
law of conservation of energy law of conservation of mass law of multiple proportions laws of thermodynamics leveling effect The effect of a solvent on the chemical properties of acids or bases which are dissolved in the solvent. The strength of a strong acid is limited or "leveled" by the basicity of the solvent, and likewise the strength of a strong base is limited by the acidity of the solvent, such that the effective pH of the solution is higher or lower than might be suggested by the acid's or base's dissociation constant.
L:
Lewis acid Lewis base Lewis structure ligand An ion, functional group, or other molecule that binds to a central metal atom to form a coordination complex. Such bonding can range from covalent to ionic, but generally involves formal donation of one or more of the ligand's electron pairs to the metal.
light Also referred to as visible light.
The portion of the electromagnetic spectrum which is visible to the unaided human eye.
liquefaction Any process that generates a liquid from a solid or a gas, or that generates a non-liquid phase that behaves as a fluid.
liquefaction point See melting point.
liquid One of the four fundamental states of matter, characterized by nearly incompressible fluid particles that retain a definite volume but no fixed shape.
liquid–liquid extraction (LLE) locant London dispersion forces A type of weak intermolecular force.
M:
macromolecule A very large molecule comprising many atoms and bonds, or any molecule with a high relative molecular mass, especially one whose structure is formed by the multiple repetition of discrete subunits derived, actually or conceptually, from molecules with low relative molecular mass (e.g. monomers, substituents, and functional groups). The term is often used interchangeably with polymer.
magnetic quantum number malleability See ductility.
manometer An instrument used to measure pressure invented by Evangelista Torricelli in 1643.
masking agent A reagent used in a chemical analysis which reacts with one or more other chemical species that may interfere in the analysis.
mass A property of physical matter that is a measure of its resistance to acceleration when a net force is applied. The SI unit for mass is the kilogram (kg).
mass concentration mass fraction mass number (A) Also atomic mass number or nucleon number.
M:
The total number of protons and neutrons (together known as nucleons) within the nucleus of an atom. It determines the atomic mass of the atom. Mass number varies between different isotopes of the same chemical element, and is often included either after the element's name (as in carbon-12) or as a superscript to the left of the element's symbol (as in 12C) to identify a specific isotope.
M:
mass spectrometry (MS) An analytical technique that measures the mass-to-charge ratio of ions in a chemical sample by bombarding the sample with electrons to the point of ionization and then separating the charged fragments by subjecting them to an electric or magnetic field, typically in order to determine the elemental or isotopic signatures of an unknown substance, the masses of its constituent particles, and/or the identities or structures of the molecules within it. The results are presented as a mass spectrum, a plot of the intensity of ion signals as a function of the mass-to-charge ratio.
M:
matter Any substance that has mass and takes up space by having volume.
metal Any chemical element which is a good conductor of both electricity and heat and which readily forms cations and ionic bonds with non-metals.
melting The phase transition of a substance from a solid to a liquid.
melting point Also liquefaction point.
The temperature at which a substance changes state from a solid to a liquid. It depends on pressure and is usually specified for a given substance under standard conditions. The melting point of a substance is identical to its freezing point.
mercaptan See thiol.
mercapto See thiol.
metalloid A chemical element or substance possessing properties of both metals and non-metals.
metamer See isomer.
metathesis A chemical reaction involving the exchange of elements or functional groups between two or more compounds, as described by the general equation A X + B Y → A Y + B X {\textstyle \mathrm {{AX}+{BY}} \rightarrow \mathrm {{AY}+{BX}} } .
See: Alkane metathesis Alkyne metathesis Olefin metathesis Salt metathesis reaction See also double displacement.
methyl Also carbinyl.
M:
The alkyl group derived from methane, consisting of one carbon atom bonded to three hydrogen atoms, with the chemical formula CH3. It is the simplest hydrocarbon functional group and occurs as a substituent in numerous organic compounds, though it may also exist independently as an ion or radical. The presence of a methyl substituent may be indicated with the prefix methyl in the name of the compound, or with the abbreviation Me in chemical formulae; e.g. methyl alcohol (methanol), which is often written with the formula CH3OH or MeOH.
M:
methylene blue A heterocyclic aromatic compound with the molecular formula C16H18N3SCl.
microcentrifuge tube A small plastic, sealable container that is used to store small volumes of liquid, generally less than 2 milliliters.
mineral A solid chemical compound with a fairly well-defined chemical composition and a specific crystal structure that occurs naturally in pure form.
M:
miscibility The tendency or capability of two or more substances (most commonly liquids, but also applicable to solids and gases) to blend uniformly when combined, i.e. to dissolve in each other, forming a homogeneous mixture that exists in a single phase, without separation of phases, regardless of the proportions of each substance. Substances that do not mix uniformly in all proportions are said to be immiscible.
M:
mixture A material made up of two or more different substances which are mixed physically but are not combined chemically (i.e. a chemical reaction has not taken place which has changed the molecules of the substances into new substances).
moiety Any named characteristic group, branch, or other part of a large molecule that may be identified within other kinds of molecules as well. Functional groups are typically smaller and more generic than moieties, whereas substituents and side chains may often be classified as moieties and vice versa.
molality Also molal concentration.
A measure of the concentration of a solute in a solution in terms of the amount of the solute per unit mass of the solvent. Molality is typically expressed in units of moles per kilogram (mol/kg); a solution with a concentration of exactly 1 mol/kg is sometimes said to be 1 molal. Contrast molarity.
molar attenuation coefficient molar concentration Also molarity, amount concentration, or substance concentration.
M:
A measure of the concentration of a chemical species, especially of a solute in a solution, in terms of the amount of the species per unit volume of solution. Molarity is typically expressed in units of moles per litre (mol/L); a solution with a concentration of exactly 1 mol/L is commonly said to be 1 molar, abbreviated 1 M. Contrast molality.
M:
molar fraction Also mole fraction.
molar mass Sometimes used interchangeably with molecular weight and formula weight.
M:
For a given chemical compound, the mass of a sample of that compound divided by the amount of compound in the sample, usually expressed in grams per mole (g/mol). As a bulk property, molar mass is an average of the masses of many instances of the compound, each of which may vary slightly due to the presence of isotopes of the compound's constituent atoms; it is commonly derived from the compound's molecular weight, which itself is a sum of the standard atomic weights of the constituent atoms, and is therefore a function of the relative abundance of the isotopes as they occur naturally on Earth. Molar mass allows easy conversion between mass and number of moles when considering bulk quantities of a substance.
M:
mole (mol) A unit (symbol: mol) used to measure the amount of a substance in terms of the absolute number of particles or entities composing the substance. By definition, one mole of any substance contains exactly the Avogadro number (i.e. 6.022×1023) of particles or entities.
molecular formula molecular orbital (MO) Any region in which one or more electrons may be found in a molecule (as opposed to that within an individual atom).
molecular orbital diagram molecular weight molecule A number of atoms that are chemically bonded together and collectively electrically neutral.
monatomic Having only one atom, as opposed to a molecule composed of more than one. Virtually all elements are monatomic in the gas phase at sufficiently high temperatures. Contrast diatomic and polyatomic.
N:
natural abundance neat Conditions with a liquid reagent or gas performed with no added solvent or cosolvent.
neutron A type of subatomic particle that is electrically neutral, having no net charge.
nitrogen noble gas Also inert gas.
Any of the six non-metallic elements of Group 18 of the periodic table: helium (He), neon (Ne), argon (Ar), krypton (Kr), xenon (Xe), and radon (Rn). All of the noble gases have outer electron shells that are completely filled in their naturally occurring states, giving them very low chemical reactivity.
non-metal Any chemical element which is not a metal.
nonpolar compound A compound consisting of covalent molecules with no permanent dipole moment.
normality nuclear Of or pertaining to the atomic nucleus.
nuclear chemistry The branch of chemistry that studies the various processes and properties relevant to atomic nuclei, including radioactivity.
nuclear magnetic resonance spectroscopy A technique that exploits the magnetic properties of certain atomic nuclei, useful for identifying unknown compounds. Nuclear magnetic resonance is often abbreviated NMR.
nuclear transmutation nucleon Either a proton or a neutron, considered in its role as a component of an atomic nucleus.
N:
nucleophile Any atom or molecule which can donate an electron pair to another atom or molecule. All molecules or ions with a free pair of electrons or at least one pi bond can act as nucleophiles, by which they are attracted to electron-deficient regions of other species; a chemical reaction involving a nucleophile donating an electron pair to an electrophile may be referred to as nucleophilic attack. Because they donate electrons, nucleophiles are Lewis bases by definition.
N:
nucleus The centre of an atom, made up of neutrons and protons and possessing a net positive electric charge.
nuclide A species of atom characterized by its mass number, atomic number, and nuclear energy state, provided that the mean life in that state is long enough to be observable.
number density A measure of the concentration of countable objects (atoms, molecules, etc.) in space, expressed as the number per unit volume.
O:
octet rule Also Lewis octet rule.
A classical rule for describing the electron configuration of atoms in certain molecules: the maximum number of electron pairs that can be accommodated in the valence shell of an element in the first row of the periodic table is four (or eight total electrons). For elements in the second and subsequent rows, there are many exceptions to this rule.
olefin A trivial (non-IUPAC) name for any alkene.
optical activity orbital Any region of an atom or molecule in which one or more electrons can be found. The term may refer to either an atomic orbital or a molecular orbital.
orbital hybridisation order of reaction organic acid Any organic compound with acidic properties. Contrast organic base.
organic base Any organic compound with basic properties. Contrast organic acid.
organic chemistry The branch of chemistry concerned with the chemical properties and reactions of organic compounds. Contrast inorganic chemistry.
organic compound Any chemical compound that contains one or more carbon atoms. Contrast inorganic compound.
organic redox reaction organosulfur compound Any chemical compound which contains both carbon and sulfur atoms.
O:
osmole osmosis The spontaneous net movement or diffusion of molecules of a solvent (e.g. water) through a selectively permeable membrane separating two solutions with different concentrations of dissolved solutes, in the direction that tends to equalize the solute concentrations on the two sides, i.e. from the more dilute solution to the more concentrated solution, or, equivalently, from a region of high water potential to a region of low water potential. Because the solute is unable to cross the membrane, the tendency towards equilibration compels the solvent to cross the membrane instead. This continues until an equilibrium is reached, where neither side of the membrane is more or less concentrated than the other.
O:
osmotic concentration Also osmolarity.
osmotic pressure other metal Any of the metallic elements in the p-block, which are characterized by having a combination of relatively low melting points (all less than 950 K) and relatively high electronegativity values (all more than 1.6, revised Pauling).
oxidation The increase in the oxidation state of a chemical species in a redox reaction, generally by losing electrons. Contrast reduction.
oxidation state Also oxidation number.
1. The degree of oxidation of an individual atom in a chemical compound, measured as the decrease in the number of electrons relative to the atom's naturally occurring elemental state.
2. The hypothetical electric charge (positive, negative, or zero) that an atom would have if all bonds to atoms of different elements were 100% ionic, with no covalent component.
oxidizing agent Also oxidant, oxidizer, or electron acceptor.
1. A chemical species that gains or accepts one or more electrons from another species, called the reducing agent, in a redox reaction, thereby causing the oxidation of the other species and in turn being itself reduced. The oxidizing agent's oxidation state decreases, while the reducing agent's increases.
2. A chemical species that transfers strongly electronegative atoms, usually oxygen, to a substrate.
oxoacid Also oxyacid or oxacid.
1. Any acid having oxygen in the acidic group.
2. Any compound which contains oxygen, at least one other element, and at least one hydrogen atom bound to oxygen, and which produces a conjugate base by the loss of positive hydrogen ions.
oxygen
P:
p-block paired electron One of two electrons that together form a valence bond between two atoms. Contrast unpaired electron.
paraffin 1. A trivial (non-IUPAC) name for any alkane.
2. Another name for kerosene.
partial pressure partition coefficient pascal (Pa) passivation The process of coating a substance with a thin layer of a protective material, often a metal oxide, to create a shield against corrosion or other chemical reactions with the environment, thereby rendering the coated substance "passive" or less susceptible to undesirable reactions.
passivity A state of chemical inactivity, especially of a metal that is relatively resistant to corrosion due to natural or induced loss of chemical reactivity (as with passivation).
pentabasic (of a chemical compound) Having five hydrogen atoms which may be replaced by metals or bases.
pentoxide Any binary compound containing five atoms of oxygen, e.g. iodine pentoxide (I2O5).
pentyl Also amyl.
An alkyl functional group containing five carbon atoms, with the chemical formula –C5H11. It is the substituent form of the alkane pentane.
per- A prefix in IUPAC chemical nomenclature meaning complete, exhaustive, or extreme, as in a completely substituted hydrocarbon; or indicating the presence of a peroxy group.
peracid An acid containing an acidic peroxy group (–O–O–); e.g. periodic acid.
period A horizontal row of the periodic table of the elements and the elements that share it. Contrast group.
periodic table of the elements Also simply the periodic table.
P:
A tabular arrangement of the chemical elements organized by their atomic number, electron configuration, and other chemical properties, whose adopted structure shows periodic trends and is used by chemists to derive relationships between various elements as well as predict the properties and behaviors of undiscovered or newly synthesized elements. The first periodic table of the elements was published by Russian chemist Dmitri Mendeleev in 1869.
P:
peroxide 1. A class of compounds which contain a peroxy group, having the generic structural formula R–O–O–R, where R is any element or functional group; e.g. hydrogen peroxide (empirically H2O2, structurally H–O–O–H).
2. Another name for the peroxy group itself.
3. A salt of the anion O2−2.
peroxy Also peroxide and sometimes peroxo.
A functional group consisting of two oxygen atoms directly connected to each other by a single bond and each also connected to one other atom. It has the chemical formula –O–O–.
P:
pH A logarithmic scale used to specify the acidity or basicity of an aqueous solution. The pH scale approximates the negative of the base-10 logarithm of the molar concentration of hydrogen ions in a solution. At room temperature, pure water is neutral (pH = 7); solutions with a pH less than 7 are acidic and those with a pH greater than 7 are basic.
P:
phase A region of space throughout which all physical properties of a substance are essentially uniform, or a region of material that is chemically uniform, physically distinct, and often mechanically separable. The term phase may have several different uses in chemistry contexts; colloquially, it is often used interchangeably with state of matter, but many distinct phases may exist within a single state of matter.
P:
phase diagram A graphical representation of the equilibrium relationships between thermodynamically distinct phases of a chemical compound, mixture, or solution, indicating the physical conditions (e.g. temperature and pressure) under which various phases (e.g. solid, liquid, and vapor) occur or coexist.
phase transition 1. A transformation of a chemical substance between solid, liquid, and gaseous states of matter and, in rare cases, plasma.
2. The measurable values of the external conditions at which such a transformation occurs.
phenyl A functional group consisting of a cyclic ring of six carbon atoms with the chemical formula –C6H5. It is the substituent form of the cycloalkane benzene.
phi bond photon A carrier of electromagnetic radiation of all wavelengths (such as gamma rays and radio waves).
P:
physical chemistry The branch of chemistry that studies chemical systems in terms of the principles, practices, and concepts of physics, such as motion, energy, force, time, thermodynamics, chemical equilibrium, and statistical mechanics, among others. In contrast to chemical physics, physical chemistry is predominantly (though not entirely) a macroscopic science that studies the physical and chemical interactions of bulk quantities of matter.
P:
pi bond pipette Also spelled pipet.
A laboratory tool commonly used in chemistry, biology, and medicine to transfer and dispense a precisely measured volume of liquid.
plasma One of the four fundamental states of matter, in which very high-energy particles are partially or fully ionized to the point that they display unique properties and behaviors unlike those of the other three states. Plasma does not exist freely on the Earth's surface under natural conditions.
polarity polyatomic Composed of two or more atoms, of the same or different elements. Contrast monatomic and diatomic.
polyatomic ion A molecule composed of two or more covalently bonded atoms which collectively bear a net electric charge and therefore act as an ion.
polymerization The chemical bonding of two or more individual monomer molecules to form a polymer chain or network; or any reaction that produces such a bonding.
potential energy The stored energy in a body or in a system due to its position in a force field or due to its configuration.
precipitant A chemical compound or reagent that causes a chemical reaction resulting in the formation of a solid precipitate when added to a solution.
precipitate 1. (n.) A solid substance that separates from a liquid solution or diffuses out of a solid alloy during the process of precipitation.
2. (v.) To separate from another substance by forming a distinct, condensed solid phase.
P:
precipitation The process of producing a separable solid phase within a liquid medium, e.g. by transforming the dissolved solute of a supersaturated solution into an insoluble solid; or the diffusion of a distinct solid phase out of a solid alloy. A reagent that causes such a reaction is called the precipitant, and the separable solid itself is the precipitate. More generally, the term may refer to the formation of any new condensed phase by changing the physical properties of a system (e.g. water vapor condensing into liquid water droplets).
P:
precision How close the results of multiple experimental trials or observations are to each other. Compare accuracy.
pressure The force applied perpendicular to the surface of an object per unit area. The SI unit for pressure is the pascal (Pa), though many other units of pressure are also commonly used in chemistry.
primary The simplest, most commonly known, or canonical form of a chemical compound with multiple similar or isomeric forms. For example, in a primary alcohol, the carbon is bonded to a single substituent group (R1CH2OH), whereas a secondary alcohol is doubly substituted (R1R2CHOH) and a tertiary alcohol is triply substituted (R1R2R3COH).
protective group proton A subatomic particle with a positive electric charge that is found in the nucleus of an atom. Often denoted with the symbol H+.
protonation The addition of a proton (H+) to an atom, molecule, or ion.
pure substance See chemical substance.
pyrolysis The thermal decomposition of materials at elevated temperatures in an inert atmosphere such as a vacuum gas.
Q:
quantum (pl.) quanta quantum mechanics The study of how atoms, molecules, subatomic particles, etc. behave and are structured.
quark An elementary particle and a fundamental constituent of matter.
R:
racemate An equimolar mixture of a pair of enantiomers which does not exhibit optical activity. The chemical name or formula of a racemate is distinguished from those of the enantiomers by the prefix (±)- or by the symbols RS and SR.
radiation Energy released in the form of waves or subatomic particles when there is a change from high-energy to low-energy states.
radical Also free radical.
Any atom, molecule, or ion that has at least one unpaired valence electron. With few exceptions, such unpaired electrons make radicals highly chemically reactive, and therefore organic radicals are usually short-lived.
radioactive decay The process by which an unstable atomic nucleus loses excess nuclear energy by emitting radiation in any of several forms, including as gamma radiation, as alpha or beta particles, or by ejecting electrons from its atomic orbitals.
radiochemistry The branch of chemistry involving the study of radioactive substances and radioactivity, including the use of radioactive isotopes to study non-radioactive isotopes and ordinary chemical reactions.
radionuclide Also radioisotope.
A radioactive nuclide of a specified element, especially a particular isotope of that element which characteristically undergoes spontaneous decay into one or more stable nuclides by emitting excess energy from the nucleus.
Raoult's law A law of thermodynamics which states that the partial pressure of each gaseous component of an ideal mixture of liquids is equal to the vapor pressure of the pure component multiplied by its molar fraction in the mixture.
rare-earth element Also called rare-earth metals or used interchangeably with lanthanides.
Any of the 17 nearly indistinguishable, silvery-white, soft, heavy metallic elements belonging to a set including the lanthanide series (atomic numbers 57 through 71) as well as scandium and yttrium.
rate equation Also rate law.
rate-determining step The slowest step in a chemical reaction that involves more than one step. The rate of this step determines the overall reaction rate.
reactant Sometimes used interchangeably with reagent.
Any substance that is consumed in the course of a chemical reaction.
reaction barrier The energy deficit that must be overcome in order for a particular chemical reaction to proceed. In transition state theory, the reaction barrier is interpreted as the difference between the zero-point energy of the activated complex formed in the reaction and that of the initial reactants. See also activation energy.
R:
reaction mechanism The step-by-step sequence of elementary reactions by which a larger chemical reaction or overall change occurs. A complete mechanism must describe and explain which bonds are broken and which are formed (and in what order), as well as all reactants, products, and catalysts involved; the amounts of each; all intermediates, activated complexes, and transition states; and the stereochemistry of each chemical species. Because the detailed processes of a complex reaction are not observable in most cases, a reaction mechanism is often a theoretical conjecture based on thermodynamic feasibility and what little support can be gained from experiment.
R:
reaction rate The speed at which reactants are converted into products in a chemical reaction.
reaction rate constant reactive bond A chemical bond between atoms which, in a particular context, is relatively unstable and therefore easily broken or invaded by other chemical species or radicals; e.g. the double bond in ethylene (CH2=CH2) is highly reactive in the presence of other ethylene molecules, leading to a polymerization reaction that forms polyethylene.
reactive intermediate Also simply called an intermediate.
R:
reactivity The tendency of a particular chemical substance to undergo a chemical reaction, either by itself or with other substances, generally referring to either or both of two distinct observations: whether or not a substance reacts under a specific set of circumstances, and how quickly it reacts (i.e. the reaction rate). Thermodynamically, a chemical reaction occurs because the products (taken as a group) exist at a lower free energy than the reactants, and hence are more energetically "stable", but the concept of reactivity may also embody kinetic factors, depending on the usage. Chemical stability and chemical compatibility are related but distinct concepts.
R:
reactivity series Also activity series.
An empirical, calculated, and structurally analytical progression of a series of metals, arranged by their general reactivity from highest to lowest and used to summarize information about their reactions with acids and water and the methods used to extract them from ores.
reagent Also another name for a reactant.
A test substance that is added to a system in order to bring about a chemical reaction, or to see whether a reaction occurs.
redox reducing agent Also reductant, reducer, or electron donor.
A chemical species that loses or donates one or more electrons to another species, called the oxidizing agent, in a redox reaction, thereby causing the reduction of the other species and in turn being itself oxidized. The reducing agent's oxidation state increases, while the oxidizing agent's decreases.
reduction The decrease in the oxidation state of a chemical species in a redox reaction, generally by gaining electrons. Contrast oxidation.
reduction potential refractory 1. Having a high melting point.
2. A material that is resistant to decomposition by heat, pressure, or chemical attack, and retains its strength and form at high temperatures, making it suitable for applications in environments exposed to such conditions. Refractories are usually polycrystalline, polyphase, inorganic, non-metallic, porous, and heterogeneous compounds.
resonance retort A laboratory apparatus used for the distillation or dry distillation of chemical substances, traditionally consisting of a spherical vessel with a long, downward-pointing neck that conducts the condensed vapors produced by distillation into a separate collection vessel.
reversible reaction A chemical reaction that can proceed in either direction depending on the reaction conditions, i.e. from reactants to products or from products to reactants, especially implying one in which both conversions occur simultaneously. Contrast irreversible reaction.
rotamer round-bottom flask rust
S:
s-block The collective name for the elements in Groups 1 and 2 of the periodic table (the alkali and alkaline metals), as well as hydrogen and helium.
saline solution A common term for a solution of sodium chloride (NaCl) dissolved in water (H2O).
salt Any ionic compound composed of one or more anions and one or more cations.
salt bridge A device used to connect reduction with oxidation half-cells in an electrochemical cell.
saturation Schrödinger equation A quantum state equation which represents the behaviour of an electron around an atom.
second-order reaction semiconductor An electrically conductive solid whose degree of conductivity lies somewhere between that of a conductor and that of an insulator.
serial dilution side chain A chemical substituent group that is attached to the core part or "backbone" of a larger molecule, especially an oligomeric or polymeric hydrocarbon chain that branches off of the longer primary chain of a macromolecule. The term is most commonly encountered in biochemistry and organic chemistry.
single bond A bond that involves the sharing of one pair of electrons.
skeletal formula sol A suspension of solid particles in a liquid. Artificial examples include sol-gels.
solid One of the four fundamental states of matter, characterized by relatively low-energy particles packed closely together in rigid structures with definite shape and volume. See Young's modulus.
solid-phase extraction (SPE) solubility The property of a solid, liquid, or gaseous solute to dissolve in a solid, liquid, or gaseous solvent. It is typically expressed as the proportion of solute dissolved in the solvent in a fully saturated solution.
S:
solubility product ( {\textstyle K_{{\ce {s}}}} or sp {\textstyle K_{{\ce {sp}}}} A measure of the solubility of an ionic solute, expressed as the arithmetic product of the concentrations of its ions in a fully saturated solution, with respect to the solute's particular dissociation equilibria and the particular ions present. For a dissociation equilibrium {\textstyle \mathrm {{A_{x}}{B_{y}}_{(s)}} \leftrightharpoons \mathrm {xA_{(aq)}^{+}} +\mathrm {yB_{(aq)}^{-}} } , the solubility product of the ionic solute {\textstyle \mathrm {A_{x}} \mathrm {B_{y}} } is given by {\textstyle K_{{\ce {s}}}=[{\ce {A+}}]^{x}[{\ce {B-}}]^{y}} , where {\textstyle [{\ce {A+}}]} and {\textstyle [{\ce {B-}}]} are the concentrations of the solute's ionic constituents in a saturated solution. The solubility product is derived from and functions like the equilibrium constant of dissociation, though unlike an equilibrium constant it is not dimensionless. If the product of ionic concentrations in a solution exceeds the solubility product, then precipitation occurs.
S:
solute The part of a solution that is dissolved into the solvent. For example, sodium chloride (NaCl) is the solute in a solution of saline water.
solution A homogeneous mixture made up of multiple substances generally referred to as solutes and solvents.
solvated electron solvation Any stabilizing interaction of a solute with a solvent, or a similar interaction between a solvent and groups of an insoluble material (e.g. the ionic groups of an ion-exchange resin). Such interactions generally involve electrostatic forces and van der Waals forces, as well as compound-specific effects such as hydrogen bonding. See also dissolution.
solvation shell solvent The part of a solution that dissolves the solute. For example, water (H2O) is the solvent in a solution of saline water.
sonication Also ultrasonication.
The process of irradiating a substance with sound energy, usually at ultrasound (>20 kHz) frequencies, in order to agitate the particles in a sample for various purposes, such as increasing the rate of a chemical reaction or preparing vesicles in mixtures of surfactants and water.
spatial isomer See stereoisomer.
specific heat capacity (cp) Also massic heat capacity.
S:
The heat capacity of a sample of a substance divided by the mass of the sample. Informally, it is the amount of heat that must be added to one unit of mass of the substance in order to cause an increase of one unit in temperature. The SI unit of specific heat capacity is joule per kelvin per kilogram (J/K/kg). Specific heat capacity often varies with temperature and with each state of matter.
S:
spectrochemistry spectrometry See mass spectrometry.
spectroscopy The study of radiation and matter, such as X-ray absorption and emission spectroscopy.
standard solution standard conditions of temperature and pressure (STP) A standardisation of ambient temperature and pressure used in order to easily compare experimental results. Standard temperature is 25 degrees Celsius (°C) and standard pressure is 100.000 kilopascals (kPa). Standard conditions are often denoted with the abbreviation STP or SATP.
state of matter The condition of matter existing in a distinct, homogeneous, macroscopic form. Solid, liquid, gas, and plasma are the four traditional states of matter and the most well-known. See also phase.
stepwise reaction stereochemistry stereogenic center Also stereocenter.
stereoisomer Also spatial isomer.
An isomer which possesses an identical chemical composition but which differs in the spatial arrangement of its atoms.
S:
stoichiometry The calculation of quantities of reactants and products in chemical reactions. Stoichiometry is based on the law of conservation of mass and the observation that quantities of reactants and products typically exist in ratios of positive integers, implying that if the amounts of the separate reactants are known, then the amounts of the products can be calculated, and vice versa.
S:
strong acid An acid that completely dissociates in solution according to the reaction HA SH ++A− , or to such an extent that the concentration of the undissociated species HA is too low to be measured. Any acid with a pKa of less than approximately -2 is generally considered a strong acid; an example is hydrochloric acid (HCl). Contrast weak acid.
S:
strong base structural formula A graphical representation of the molecular structure and geometry of a particular chemical compound, showing how the atoms are arranged in real, three-dimensional space. Chemical bonding within the molecule is also shown, either implicitly or explicitly. When known with certainty, structural formulas are very useful because they allow chemists to visualize the molecules and the structural changes that occur in them during chemical reactions.
S:
structural isomer Also constitutional isomer.
subatomic particle Any particle that is smaller than an atom. Examples include protons, neutrons, and electrons.
sublimation The phase transition of a substance from a solid to a limewater fuel or gas without an apparent intervening transition to a liquid in the process.
substance See chemical substance.
S:
substituent An atom or a group of atoms which replaces another atom or group of atoms within a larger molecule as the product of a chemical reaction, thereby becoming a moiety of the newly formed compound, generally without causing any significant change to other parts of the same molecule. For example, a hydroxyl group may be substituted for any of the hydrogen atoms in benzene to form phenol. See also side chain and functional group.
S:
substitution reaction A type of chemical reaction in which one functional group within a larger compound replaces or is substituted for another functional group.
superheavy elements See transactinides.
surface science surface tension surfactant A substance which lowers the surface tension of the medium in which it is dissolved, and/or the interfacial tension with other phases, and, accordingly, is positively adsorbed at the liquid–vapor and/or other interfaces.
S:
suspension A heterogeneous mixture that contains solid particles which are sufficiently large for sedimentation to occur, by which such particles separate from and settle out of the fluid over time if left undisturbed. In a suspension, the solute does not dissolve but remains dispersed or suspended throughout the fluid solvent only transiently and with mechanical agitation. Contrast colloid and solution.
T:
tarnish A thin layer of corrosion that forms on the surface of copper, brass, aluminum, magnesium, and other soft metals or alloys as their outermost layer undergoes a chemical reaction with the surrounding air, often but not necessarily involving atmospheric oxygen. Tarnish usually appears as a dull grey, black, or sometimes iridescent film or coating on the metal. It is a self-limiting surface phenomenon, as the tarnished top layers of the metal protect underlying layers from reacting.
T:
temperature A proportional measure of the average kinetic energy of the random motions of the constituent microscopic particles of a system. The SI unit for temperature is the kelvin.
ternary compound A chemical compound containing three different elements.
terpene A class of naturally occurring unsaturated hydrocarbons with carbon skeletons derived from one or more units of isoprene (C5H8). Terpenes are often subclassified according to the total number of carbon atoms they contain, e.g. the C5 hemiterpenes, C10 monoterpenes, C20 diterpenes, etc.
theoretical yield See yield.
thermal conductivity The property of a material that allows it to conduct thermal energy or heat (a quantity often denoted by k ).
thermochemistry The study of the absorption or release of heat during a chemical reaction.
thermodynamic stability The condition of a system being in its lowest energy state with its environment (equilibrium).
thermodynamics The study of the effects of changing temperature, volume or pressure (or work, heat, and energy) on a macroscopic scale.
thermometer An instrument used to measure temperature.
thiol 1. Any of a class of organosulfur compounds consisting of a sulfur atom attached to a hydrogen atom and any other organic substituent, with the general formula R–SH. Thiols are the sulfur analogues of alcohols. Also thiol derivative and mercaptan.
2. The –SH functional group itself. Also sulfhydryl, sulfanyl, and mercapto.
titration Also titrimetry or volumetric analysis.
A laboratory method of quantitative chemical analysis that is used to determine the concentration of an identified analyte. The procedure involves preparing a particular reagent as a standard solution of known concentration and volume (called the titrant or titrator) and allowing it to react with a solution of the analyte (called the titrand) to determine the latter's concentration.
torr A unit for measuring pressure, equivalent to 133.322 Pa or 1.3158 × 10−3 atm.
trace element An element in a sample which has an average concentration of less than 100 parts per million atoms or less than 100 micrograms per gram.
transactinides Also superheavy elements.
In the periodic table, the set of chemical elements with an atomic number greater than 103, i.e. those heavier than the actinides. The transactinides are a subset of the transuranic elements.
transition metal An element whose atoms naturally occur with incompletely filled "d" sub-shells. These elements are grouped as the so-called d-block elements in the periodic table.
transuranic elements Also transuranium elements.
The set of chemical elements with an atomic number greater than 92, i.e. occurring after uranium in the periodic table. None of the transuranic elements are stable in natural conditions.
triple bond A bond that involves the covalent sharing of three pairs of electrons (for example, the diatomic nitrogen molecule, N2, is composed of two nitrogen atoms linked by a triple bond).
triple point The place where temperature and pressure of three phases are the same. Water has a special phase diagram.
Tyndall effect The effect of light scattering by colloidal or suspended particles.
U:
UN number A four-digit code used to note hazardous and flammable substances.
uncertainty The notion that any measurement that involves estimation of any amount cannot be exactly reproducible.
uncertainty principle Knowing the location of a particle makes the momentum uncertain, while knowing the momentum of a particle makes the location uncertain.
unit cell The smallest repeating unit of a crystalline lattice.
unit factor Statements used in converting between units.
unpaired electron
V:
vacuum flask Also Dewar flask or thermos.
V:
A storage vessel consisting of two flasks or other containers, placed one within the other and joined at the neck, and a space in between that is partially evacuated of air, creating a near-vacuum that significantly reduces the transfer of heat between the vessel's interior and its ambient environment. Vacuum flasks can greatly lengthen the time over which their contents remain warmer or cooler than the ambient environment.
V:
valence electron Any of the outermost electrons of an atom, which are located in electron shells.
valence bond theory A theory explaining the chemical bonding within molecules by discussing valencies, the number of chemical bonds formed by an atom.
valency The combining capacity of an element.
van der Waals force One of the forces (attraction/repulsion) between molecules.
van 't Hoff factor The ratio of moles of particles in solution to moles of solute dissolved.
vapor When a substance is below the critical temperature while in the gas phase.
vapor pressure Also equilibrium vapor pressure.
The pressure exerted by a vapor which is in thermodynamic equilibrium with its condensed phases (solid or liquid) at a given temperature in a closed system. It is commonly described as the tendency of particles to spontaneously escape from the liquid or solid state into the gaseous state and is used as an indication of a liquid's evaporation rate.
vaporization Also boiling.
The phase transition of a substance from a liquid to a gas.
vaporization point See boiling point.
viscosity A measure of the resistance of a liquid to flow.
V:
volatility A material quality which describes how readily a substance vaporizes. At a given temperature and pressure, a substance with high volatility is more likely to exist as a gas, while a substance with low volatility is more likely to exist as a liquid or solid; equivalently, less volatile substances will more readily condense from a gaseous state than highly volatile ones.
V:
volt (V) A derived unit of electric potential, electric potential difference, and electromotive force, defined as one joule of work per coulomb.
voltmeter An instrument that measures electrical cell potential.
volume The quantity of three-dimensional space enclosed by a closed surface, or the space that a substance (solid, liquid, gas, or plasma) or shape occupies or contains. The SI unit for volume is the cubic metre (m3).
volumetric analysis See titration.
volumetric flask
W:
watch glass A circular, concave piece of glass commonly used in chemistry laboratories as a working surface for various purposes, such as evaporating liquids, holding solids while they are being weighed, heating small amounts of a substance, or as a cover for a beaker.
W:
water A polar inorganic compound with the chemical formula H2O that is a tasteless, odorless, and generally colorless liquid at standard temperature and pressure, though it also occurs naturally as a solid and a gas at the Earth's surface. It is the most abundant substance on Earth and therefore an integral component of virtually all chemical and biological systems. Water is often described as the "universal solvent" for its inherent ability to dissolve many substances.
W:
water of crystallization Also water of hydration.
Water molecules that are present inside crystals. Upon crystallization from water or aqueous solutions, many compounds incorporate water in their crystalline frameworks; the water molecules are typically present in a stoichiometric ratio and may interact to varying degrees with the atoms of the crystal.
wave function A mathematical function describing the position of an electron in a three-dimensional space.
weak acid An acid that only partially dissociates when dissolved in a solvent because, according to the reaction HA ↽−−⇀H++A− , equilibrium is reached while the concentration of the undissociated species HA is still significant; an example is acetic acid (CH3COOH). Contrast strong acid.
weak base wet chemistry Also bench chemistry or classical chemistry.
A form of analytical chemistry which uses classical laboratory methods such as simple observation and elementary chemical tests to study chemicals and chemical reactions, i.e. without the use of sophisticated instruments or automated or computerized analysis. It is often used in schools to teach the principles of chemistry to students.
wetting agent work work-up The series of manipulations required to isolate and purify the desired product or products of a chemical reaction.
X:
X-ray A form of ionizing, electromagnetic radiation between gamma and UV rays in the electromagnetic spectrum.
X-ray diffraction a method for establishing structures of crystalline solids using single wavelength X-rays and looking at diffraction pattern.
X-ray photoelectron spectroscopy A spectroscopic technique used to measure the chemical composition of a material.
Y:
yield The quantifiable amount of product produced during a chemical reaction.
Z:
zero-point energy (ZPE) zone melting A way to remove impurities from an element by melting it and slowly travel down an ingot (cast).
zinc A metallic chemical element with atomic number 30 and symbol Zn.
zwitterion Also inner salt and dipolar ion.
Any molecule that contains an internal polarity by virtue of having an equal number of positively charged and negatively charged functional groups. | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**Trigonometric functions**
Trigonometric functions:
In mathematics, the trigonometric functions (also called circular functions, angle functions or goniometric functions) are real functions which relate an angle of a right-angled triangle to ratios of two side lengths. They are widely used in all sciences that are related to geometry, such as navigation, solid mechanics, celestial mechanics, geodesy, and many others. They are among the simplest periodic functions, and as such are also widely used for studying periodic phenomena through Fourier analysis.
Trigonometric functions:
The trigonometric functions most widely used in modern mathematics are the sine, the cosine, and the tangent. Their reciprocals are respectively the cosecant, the secant, and the cotangent, which are less used. Each of these six trigonometric functions has a corresponding inverse function, and an analog among the hyperbolic functions.
Trigonometric functions:
The oldest definitions of trigonometric functions, related to right-angle triangles, define them only for acute angles. To extend the sine and cosine functions to functions whose domain is the whole real line, geometrical definitions using the standard unit circle (i.e., a circle with radius 1 unit) are often used; then the domain of the other functions is the real line with some isolated points removed. Modern definitions express trigonometric functions as infinite series or as solutions of differential equations. This allows extending the domain of sine and cosine functions to the whole complex plane, and the domain of the other trigonometric functions to the complex plane with some isolated points removed.
Notation:
Conventionally, an abbreviation of each trigonometric function's name is used as its symbol in formulas. Today, the most common versions of these abbreviations are "sin" for sine, "cos" for cosine, "tan" or "tg" for tangent, "sec" for secant, "csc" or "cosec" for cosecant, and "cot" or "ctg" for cotangent. Historically, these abbreviations were first used in prose sentences to indicate particular line segments or their lengths related to an arc of an arbitrary circle, and later to indicate ratios of lengths, but as the function concept developed in the 17th–18th century, they began to be considered as functions of real-number-valued angle measures, and written with functional notation, for example sin(x). Parentheses are still often omitted to reduce clutter, but are sometimes necessary; for example the expression sin x+y would typically be interpreted to mean sin (x)+y, so parentheses are required to express sin (x+y).
Notation:
A positive integer appearing as a superscript after the symbol of the function denotes exponentiation, not function composition. For example sin 2x and sin 2(x) denote sin sin (x), not sin sin x).
This differs from the (historically later) general functional notation in which f2(x)=(f∘f)(x)=f(f(x)).
However, the exponent −1 is commonly used to denote the inverse function, not the reciprocal. For example sin −1x and sin −1(x) denote the inverse trigonometric function alternatively written arcsin x: The equation sin −1x implies sin θ=x, not sin 1.
In this case, the superscript could be considered as denoting a composed or iterated function, but negative superscripts other than −1 are not in common use.
Right-angled triangle definitions:
If the acute angle θ is given, then any right triangles that have an angle of θ are similar to each other. This means that the ratio of any two side lengths depends only on θ. Thus these six ratios define six functions of θ, which are the trigonometric functions. In the following definitions, the hypotenuse is the length of the side opposite the right angle, opposite represents the side opposite the given angle θ, and adjacent represents the side between the angle θ and the right angle.
Right-angled triangle definitions:
In a right-angled triangle, the sum of the two acute angles is a right angle, that is, 90° or π/2 radians. Therefore sin (θ) and cos 90 ∘−θ) represent the same ratio, and thus are equal. This identity and analogous relationships between the other trigonometric functions are summarized in the following table.
Radians versus degrees:
In geometric applications, the argument of a trigonometric function is generally the measure of an angle. For this purpose, any angular unit is convenient. One common unit is degrees, in which a right angle is 90° and a complete turn is 360° (particularly in elementary mathematics).
Radians versus degrees:
However, in calculus and mathematical analysis, the trigonometric functions are generally regarded more abstractly as functions of real or complex numbers, rather than angles. In fact, the functions sin and cos can be defined for all complex numbers in terms of the exponential function, via power series, or as solutions to differential equations given particular initial values (see below), without reference to any geometric notions. The other four trigonometric functions (tan, cot, sec, csc) can be defined as quotients and reciprocals of sin and cos, except where zero occurs in the denominator. It can be proved, for real arguments, that these definitions coincide with elementary geometric definitions if the argument is regarded as an angle given in radians. Moreover, these definitions result in simple expressions for the derivatives and indefinite integrals for the trigonometric functions. Thus, in settings beyond elementary geometry, radians are regarded as the mathematically natural unit for describing angle measures.
Radians versus degrees:
When radians (rad) are employed, the angle is given as the length of the arc of the unit circle subtended by it: the angle that subtends an arc of length 1 on the unit circle is 1 rad (≈ 57.3°), and a complete turn (360°) is an angle of 2π (≈ 6.28) rad. For real number x, the notations sin x, cos x, etc. refer to the value of the trigonometric functions evaluated at an angle of x rad. If units of degrees are intended, the degree sign must be explicitly shown (e.g., sin x°, cos x°, etc.). Using this standard notation, the argument x for the trigonometric functions satisfies the relationship x = (180x/π)°, so that, for example, sin π = sin 180° when we take x = π. In this way, the degree symbol can be regarded as a mathematical constant such that 1° = π/180 ≈ 0.0175.
Unit-circle definitions:
The six trigonometric functions can be defined as coordinate values of points on the Euclidean plane that are related to the unit circle, which is the circle of radius one centered at the origin O of this coordinate system. While right-angled triangle definitions allow for the definition of the trigonometric functions for angles between 0 and {\textstyle {\frac {\pi }{2}}} radians (90°), the unit circle definitions allow the domain of trigonometric functions to be extended to all positive and negative real numbers.
Unit-circle definitions:
Let L be the ray obtained by rotating by an angle θ the positive half of the x-axis (counterclockwise rotation for θ>0, and clockwise rotation for θ<0 ). This ray intersects the unit circle at the point A=(xA,yA).
The ray L, extended to a line if necessary, intersects the line of equation x=1 at point B=(1,yB), and the line of equation y=1 at point C=(xC,1).
The tangent line to the unit circle at the point A, is perpendicular to L, and intersects the y- and x-axes at points D=(0,yD) and E=(xE,0).
The coordinates of these points give the values of all trigonometric functions for any arbitrary real value of θ in the following manner.
The trigonometric functions cos and sin are defined, respectively, as the x- and y-coordinate values of point A. That is, cos θ=xA and sin θ=yA.
In the range 0≤θ≤π/2 , this definition coincides with the right-angled triangle definition, by taking the right-angled triangle to have the unit radius OA as hypotenuse. And since the equation x2+y2=1 holds for all points P=(x,y) on the unit circle, this definition of cosine and sine also satisfies the Pythagorean identity.
cos sin 1.
The other trigonometric functions can be found along the unit circle as tan θ=yB and cot θ=xC, csc θ=yD and sec θ=xE.
By applying the Pythagorean identity and geometric proof methods, these definitions can readily be shown to coincide with the definitions of tangent, cotangent, secant and cosecant in terms of sine and cosine, that is tan sin cos cot cos sin sec cos csc sin θ.
Unit-circle definitions:
Since a rotation of an angle of ±2π does not change the position or size of a shape, the points A, B, C, D, and E are the same for two angles whose difference is an integer multiple of 2π . Thus trigonometric functions are periodic functions with period 2π . That is, the equalities sin sin (θ+2kπ) and cos cos (θ+2kπ) hold for any angle θ and any integer k. The same is true for the four other trigonometric functions. By observing the sign and the monotonicity of the functions sine, cosine, cosecant, and secant in the four quadrants, one can show that 2π is the smallest value for which they are periodic (i.e., 2π is the fundamental period of these functions). However, after a rotation by an angle π , the points B and C already return to their original position, so that the tangent function and the cotangent function have a fundamental period of π . That is, the equalities tan tan (θ+kπ) and cot cot (θ+kπ) hold for any angle θ and any integer k.
Algebraic values:
The algebraic expressions for the most important angles are as follows: sin sin 0∘=02=0 (zero angle) sin sin 30 ∘=12=12 sin sin 45 ∘=22=12 sin sin 60 ∘=32 sin sin 90 ∘=42=1 (right angle)Writing the numerators as square roots of consecutive non-negative integers, with a denominator of 2, provides an easy way to remember the values.Such simple expressions generally do not exist for other angles which are rational multiples of a right angle.
Algebraic values:
For an angle which, measured in degrees, is a multiple of three, the exact trigonometric values of the sine and the cosine may be expressed in terms of square roots. These values of the sine and the cosine may thus be constructed by ruler and compass.
For an angle of an integer number of degrees, the sine and the cosine may be expressed in terms of square roots and the cube root of a non-real complex number. Galois theory allows a proof that, if the angle is not a multiple of 3°, non-real cube roots are unavoidable.
For an angle which, expressed in degrees, is a rational number, the sine and the cosine are algebraic numbers, which may be expressed in terms of nth roots. This results from the fact that the Galois groups of the cyclotomic polynomials are cyclic.
For an angle which, expressed in degrees, is not a rational number, then either the angle or both the sine and the cosine are transcendental numbers. This is a corollary of Baker's theorem, proved in 1966.
Simple algebraic values The following table lists the sines, cosines, and tangents of multiples of 15 degrees from 0 to 90 degrees.
In calculus:
The modern trend in mathematics is to build geometry from calculus rather than the converse. Therefore, except at a very elementary level, trigonometric functions are defined using the methods of calculus.
Trigonometric functions are differentiable and analytic at every point where they are defined; that is, everywhere for the sine and the cosine, and, for the tangent, everywhere except at π/2 + kπ for every integer k.
The trigonometric function are periodic functions, and their primitive period is 2π for the sine and the cosine, and π for the tangent, which is increasing in each open interval (π/2 + kπ, π/2 + (k + 1)π). At each end point of these intervals, the tangent function has a vertical asymptote.
In calculus:
In calculus, there are two equivalent definitions of trigonometric functions, either using power series or differential equations. These definitions are equivalent, as starting from one of them, it is easy to retrieve the other as a property. However the definition through differential equations is somehow more natural, since, for example, the choice of the coefficients of the power series may appear as quite arbitrary, and the Pythagorean identity is much easier to deduce from the differential equations.
In calculus:
Definition by differential equations Sine and cosine can be defined as the unique solution to the initial value problem: sin cos cos sin sin cos 1.
Differentiating again, sin cos sin {\textstyle {\frac {d^{2}}{dx^{2}}}\sin x={\frac {d}{dx}}\cos x=-\sin x} and cos sin cos {\textstyle {\frac {d^{2}}{dx^{2}}}\cos x=-{\frac {d}{dx}}\sin x=-\cos x} , so both sine and cosine are solutions of the ordinary differential equation 0.
Applying the quotient rule to the tangent tan sin cos x , we derive tan cos sin cos tan sec 2x.
Power series expansion Applying the differential equations to power series with indeterminate coefficients, one may deduce recurrence relations for the coefficients of the Taylor series of the sine and cosine functions. These recurrence relations are easy to solve, and give the series expansions sin cos x=1−x22!+x44!−x66!+⋯=∑n=0∞(−1)n(2n)!x2n.
The radius of convergence of these series is infinite. Therefore, the sine and the cosine can be extended to entire functions (also called "sine" and "cosine"), which are (by definition) complex-valued functions that are defined and holomorphic on the whole complex plane.
In calculus:
Being defined as fractions of entire functions, the other trigonometric functions may be extended to meromorphic functions, that is functions that are holomorphic in the whole complex plane, except some isolated points called poles. Here, the poles are the numbers of the form {\textstyle (2k+1){\frac {\pi }{2}}} for the tangent and the secant, or kπ for the cotangent and the cosecant, where k is an arbitrary integer.
In calculus:
Recurrences relations may also be computed for the coefficients of the Taylor series of the other trigonometric functions. These series have a finite radius of convergence. Their coefficients have a combinatorial interpretation: they enumerate alternating permutations of finite sets.More precisely, defining Un, the nth up/down number, Bn, the nth Bernoulli number, and En, is the nth Euler number,one has the following series expansions: tan 15 17 315 for |x|<π2.
In calculus:
csc 360 31 15120 for 0<|x|<π.
sec 24 61 720 for |x|<π2.
cot 45 945 for 0<|x|<π.
Continued fraction expansion The following expansions are valid in the whole complex plane: sin x=x1+x22⋅3−x2+2⋅3x24⋅5−x2+4⋅5x26⋅7−x2+⋱ cos x=11+x21⋅2−x2+1⋅2x23⋅4−x2+3⋅4x25⋅6−x2+⋱ tan x=x1−x23−x25−x27−⋱=11x−13x−15x−17x−⋱ The last one was used in the historically first proof that π is irrational.
Partial fraction expansion There is a series representation as partial fraction expansion where just translated reciprocal functions are summed up, such that the poles of the cotangent function and the reciprocal functions match: cot lim N→∞∑n=−NN1x+n.
This identity can be proved with the Herglotz trick.
Combining the (–n)th with the nth term lead to absolutely convergent series: cot πx=1x+2x∑n=1∞1x2−n2.
Similarly, one can find a partial fraction expansion for the secant, cosecant and tangent functions: csc πx=∑n=−∞∞(−1)nx+n=1x+2x∑n=1∞(−1)nx2−n2, csc 2πx=∑n=−∞∞1(x+n)2, sec πx=∑n=0∞(−1)n(2n+1)(n+12)2−x2, tan πx=2x∑n=0∞1(n+12)2−x2.
Infinite product expansion The following infinite product for the sine is of great importance in complex analysis: sin z=z∏n=1∞(1−z2n2π2),z∈C.
For the proof of this expansion, see Sine. From this, it can be deduced that cos z=∏n=1∞(1−z2(n−1/2)2π2),z∈C.
Relationship to exponential function (Euler's formula) Euler's formula relates sine and cosine to the exponential function: cos sin x.
This formula is commonly considered for real values of x, but it remains true for all complex values.
Proof: Let cos sin x, and f2(x)=eix.
One has dfj(x)/dx=ifj(x) for j = 1, 2. The quotient rule implies thus that d/dx(f1(x)/f2(x))=0 . Therefore, f1(x)/f2(x) is a constant function, which equals 1, as 1.
This proves the formula.
One has cos sin cos sin x.
Solving this linear system in sine and cosine, one can express them in terms of the exponential function: sin cos x=eix+e−ix2.
When x is real, this may be rewritten as cos Re sin Im (eix).
Most trigonometric identities can be proved by expressing trigonometric functions in terms of the complex exponential function by using above formulas, and then using the identity ea+b=eaeb for simplifying the result.
Definitions using functional equations One can also define the trigonometric functions using various functional equations.
For example, the sine and the cosine form the unique pair of continuous functions that satisfy the difference formula cos cos cos sin sin y and the added condition cos sin for 1.
In calculus:
In the complex plane The sine and cosine of a complex number z=x+iy can be expressed in terms of real sines, cosines, and hyperbolic functions as follows: sin sin cosh cos sinh cos cos cosh sin sinh y By taking advantage of domain coloring, it is possible to graph the trigonometric functions as complex-valued functions. Various features unique to the complex functions can be seen from the graph; for example, the sine and cosine functions can be seen to be unbounded as the imaginary part of z becomes larger (since the color white represents infinity), and the fact that the functions contain simple zeros or poles is apparent from the fact that the hue cycles around each zero or pole exactly once. Comparing these graphs with those of the corresponding Hyperbolic functions highlights the relationships between the two.
Basic identities:
Many identities interrelate the trigonometric functions. This section contains the most basic ones; for more identities, see List of trigonometric identities. These identities may be proved geometrically from the unit-circle definitions or the right-angled-triangle definitions (although, for the latter definitions, care must be taken for angles that are not in the interval [0, π/2], see Proofs of trigonometric identities). For non-geometrical proofs using only tools of calculus, one may use directly the differential equations, in a way that is similar to that of the above proof of Euler's identity. One can also use Euler's identity for expressing all trigonometric functions in terms of complex exponentials and using properties of the exponential function.
Basic identities:
Parity The cosine and the secant are even functions; the other trigonometric functions are odd functions. That is: sin sin cos cos tan tan cot cot csc csc sec sec x.
Periods All trigonometric functions are periodic functions of period 2π. This is the smallest period, except for the tangent and the cotangent, which have π as smallest period. This means that, for every integer k, one has sin sin cos cos tan tan cot cot csc csc sec sec x.
Basic identities:
Pythagorean identity The Pythagorean identity, is the expression of the Pythagorean theorem in terms of trigonometric functions. It is sin cos 2x=1 .Dividing through by either cos 2x or sin 2x gives tan sec 2x and cot csc 2x Sum and difference formulas The sum and difference formulas allow expanding the sine, the cosine, and the tangent of a sum or a difference of two angles in terms of sines and cosines and tangents of the angles themselves. These can be derived geometrically, using arguments that date to Ptolemy. One can also produce them algebraically using Euler's formula.
Basic identities:
Sum sin sin cos cos sin cos cos cos sin sin tan tan tan tan tan y.
Difference sin sin cos cos sin cos cos cos sin sin tan tan tan tan tan y.
When the two angles are equal, the sum formulas reduce to simpler equations known as the double-angle formulae.
sin sin cos tan tan cos cos sin cos sin tan tan tan tan tan 2x.
These identities can be used to derive the product-to-sum identities.
By setting tan 12θ, all trigonometric functions of θ can be expressed as rational fractions of t sin cos tan θ=2t1−t2.
Together with dθ=21+t2dt, this is the tangent half-angle substitution, which reduces the computation of integrals and antiderivatives of trigonometric functions to that of rational fractions.
Derivatives and antiderivatives The derivatives of trigonometric functions result from those of sine and cosine by applying quotient rule. The values given for the antiderivatives in the following table can be verified by differentiating them. The number C is a constant of integration.
Note: For 0<x<π the integral of csc x can also be written as arsinh cot x), and for the integral of sec x for −π/2<x<π/2 as arsinh tan x), where arsinh is the inverse hyperbolic sine.
Alternatively, the derivatives of the 'co-functions' can be obtained using trigonometric identities and the chain rule: cos sin cos sin csc sec sec tan csc cot cot tan sec csc 2x.
Inverse functions:
The trigonometric functions are periodic, and hence not injective, so strictly speaking, they do not have an inverse function. However, on each interval on which a trigonometric function is monotonic, one can define an inverse function, and this defines inverse trigonometric functions as multivalued functions. To define a true inverse function, one must restrict the domain to an interval where the function is monotonic, and is thus bijective from this interval to its image by the function. The common choice for this interval, called the set of principal values, is given in the following table. As usual, the inverse trigonometric functions are denoted with the prefix "arc" before the name or its abbreviation of the function.
Inverse functions:
The notations sin−1, cos−1, etc. are often used for arcsin and arccos, etc. When this notation is used, inverse functions could be confused with multiplicative inverses. The notation with the "arc" prefix avoids such a confusion, though "arcsec" for arcsecant can be confused with "arcsecond".
Just like the sine and cosine, the inverse trigonometric functions can also be expressed in terms of infinite series. They can also be expressed in terms of complex logarithms.
Applications:
Angles and sides of a triangle In this section A, B, C denote the three (interior) angles of a triangle, and a, b, c denote the lengths of the respective opposite edges. They are related by various formulas, which are named by the trigonometric functions they involve.
Law of sines The law of sines states that for an arbitrary triangle with sides a, b, and c and angles opposite those sides A, B and C: where Δ is the area of the triangle, or, equivalently, where R is the triangle's circumradius.
Applications:
It can be proved by dividing the triangle into two right ones and using the above definition of sine. The law of sines is useful for computing the lengths of the unknown sides in a triangle if two angles and one side are known. This is a common situation occurring in triangulation, a technique to determine unknown distances by measuring two angles and an accessible enclosed distance.
Applications:
Law of cosines The law of cosines (also known as the cosine formula or cosine rule) is an extension of the Pythagorean theorem: or equivalently, In this formula the angle at C is opposite to the side c. This theorem can be proved by dividing the triangle into two right ones and using the Pythagorean theorem.
The law of cosines can be used to determine a side of a triangle if two sides and the angle between them are known. It can also be used to find the cosines of an angle (and consequently the angles themselves) if the lengths of all the sides are known.
Applications:
Law of tangents The law of tangents says that: tan tan A+B2=a−ba+b Law of cotangents If s is the triangle's semiperimeter, (a + b + c)/2, and r is the radius of the triangle's incircle, then rs is the triangle's area. Therefore Heron's formula implies that: r=1s(s−a)(s−b)(s−c) .The law of cotangents says that: cot A2=s−ar It follows that cot cot cot C2s−c=1r.
Applications:
Periodic functions The trigonometric functions are also important in physics. The sine and the cosine functions, for example, are used to describe simple harmonic motion, which models many natural phenomena, such as the movement of a mass attached to a spring and, for small angles, the pendular motion of a mass hanging by a string. The sine and cosine functions are one-dimensional projections of uniform circular motion.
Applications:
Trigonometric functions also prove to be useful in the study of general periodic functions. The characteristic wave patterns of periodic functions are useful for modeling recurring phenomena such as sound or light waves.Under rather general conditions, a periodic function f (x) can be expressed as a sum of sine waves or cosine waves in a Fourier series. Denoting the sine or cosine basis functions by φk, the expansion of the periodic function f (t) takes the form: For example, the square wave can be written as the Fourier series In the animation of a square wave at top right it can be seen that just a few terms already produce a fairly good approximation. The superposition of several terms in the expansion of a sawtooth wave are shown underneath.
History:
While the early study of trigonometry can be traced to antiquity, the trigonometric functions as they are in use today were developed in the medieval period. The chord function was discovered by Hipparchus of Nicaea (180–125 BCE) and Ptolemy of Roman Egypt (90–165 CE). The functions of sine and versine (1 – cosine) can be traced back to the jyā and koti-jyā functions used in Gupta period Indian astronomy (Aryabhatiya, Surya Siddhanta), via translation from Sanskrit to Arabic and then from Arabic to Latin. (See Aryabhata's sine table.) All six trigonometric functions in current use were known in Islamic mathematics by the 9th century, as was the law of sines, used in solving triangles. With the exception of the sine (which was adopted from Indian mathematics), the other five modern trigonometric functions were discovered by Persian and Arab mathematicians, including the cosine, tangent, cotangent, secant and cosecant. Al-Khwārizmī (c. 780–850) produced tables of sines, cosines and tangents. Circa 830, Habash al-Hasib al-Marwazi discovered the cotangent, and produced tables of tangents and cotangents. Muhammad ibn Jābir al-Harrānī al-Battānī (853–929) discovered the reciprocal functions of secant and cosecant, and produced the first table of cosecants for each degree from 1° to 90°. The trigonometric functions were later studied by mathematicians including Omar Khayyám, Bhāskara II, Nasir al-Din al-Tusi, Jamshīd al-Kāshī (14th century), Ulugh Beg (14th century), Regiomontanus (1464), Rheticus, and Rheticus' student Valentinus Otho.
History:
Madhava of Sangamagrama (c. 1400) made early strides in the analysis of trigonometric functions in terms of infinite series. (See Madhava series and Madhava's sine table.) The tangent function was brought to Europe by Giovanni Bianchini in 1467 in trigonometry tables he created to support the calculation of stellar coordinates.The terms tangent and secant were first introduced by the Danish mathematician Thomas Fincke in his book Geometria rotundi (1583).The 17th century French mathematician Albert Girard made the first published use of the abbreviations sin, cos, and tan in his book Trigonométrie.In a paper published in 1682, Gottfried Leibniz proved that sin x is not an algebraic function of x. Though introduced as ratios of sides of a right triangle, and thus appearing to be rational functions, Leibnitz result established that they are actually transcendental functions of their argument. The task of assimilating circular functions into algebraic expressions was accomplished by Euler in his Introduction to the Analysis of the Infinite (1748). His method was to show that the sine and cosine functions are alternating series formed from the even and odd terms respectively of the exponential series. He presented "Euler's formula", as well as near-modern abbreviations (sin., cos., tang., cot., sec., and cosec.).A few functions were common historically, but are now seldom used, such as the chord, the versine (which appeared in the earliest tables), the coversine, the haversine, the exsecant and the excosecant. The list of trigonometric identities shows more relations between these functions.
History:
crd(θ) = 2 sin(θ/2) versin(θ) = 1 − cos(θ) = 2 sin2(θ/2) coversin(θ) = 1 − sin(θ) = versin(π/2 − θ) haversin(θ) = 1/2versin(θ) = sin2(θ/2) exsec(θ) = sec(θ) − 1 excsc(θ) = exsec(π/2 − θ) = csc(θ) − 1
Etymology:
The word sine derives from Latin sinus, meaning "bend; bay", and more specifically "the hanging fold of the upper part of a toga", "the bosom of a garment", which was chosen as the translation of what was interpreted as the Arabic word jaib, meaning "pocket" or "fold" in the twelfth-century translations of works by Al-Battani and al-Khwārizmī into Medieval Latin.
Etymology:
The choice was based on a misreading of the Arabic written form j-y-b (جيب), which itself originated as a transliteration from Sanskrit jīvā, which along with its synonym jyā (the standard Sanskrit term for the sine) translates to "bowstring", being in turn adopted from Ancient Greek χορδή "string".The word tangent comes from Latin tangens meaning "touching", since the line touches the circle of unit radius, whereas secant stems from Latin secans—"cutting"—since the line cuts the circle.The prefix "co-" (in "cosine", "cotangent", "cosecant") is found in Edmund Gunter's Canon triangulorum (1620), which defines the cosinus as an abbreviation for the sinus complementi (sine of the complementary angle) and proceeds to define the cotangens similarly. | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**Attribute (role-playing games)**
Attribute (role-playing games):
An attribute is a piece of data (a "statistic") that describes to what extent a fictional character in a role-playing game possesses a specific natural, in-born characteristic common to all characters in the game. That piece of data is usually an abstract number or, in some cases, a set of dice. Some games use different terms to refer to an attribute, such as statistic, (primary) characteristic or ability. A number of role-playing games like Fate do not use attributes at all.
The nature of attributes:
There is no uniform consensus on what ability scores are, even if many role-playing games have them, but games that use them have a common theme. According to the BBC Cult TV website "All characters have Attributes — basic physical and mental abilities." and in the Pathfinder Roleplaying Game "Each character has six ability scores that represent his character's most basic attributes. They are his raw talent and prowess. While a character rarely rolls a check using just an ability score, these scores, and the modifiers they create, affect nearly every aspect of a character's skills and abilities." In some games, such as older versions of Dungeons & Dragons the attribute is used on its own to determine outcomes, whereas in many games, beginning with Bunnies & Burrows and including more modern versions of D&D, the attribute works with a skill to affect the overall outcome.
Common types of attribute system:
There is no standard amongst role-playing games as to which attributes are important for the game, though there is a school of design which says you pick the attributes after you decide what the game is about.
Common types of attribute system:
Set attribute systems Dungeons & Dragons Dungeons & Dragons used six attributes (there were brief attempts to add a seventh, Comeliness, in Unearthed Arcana and Dragon magazine, but this was short-lived). The six attributes used in D&D are: "Physical" statisticsStrength - measuring physical power and carrying capacity Constitution - measuring endurance, stamina and good health Dexterity - measuring agility, balance, coordination and reflexes"Mental" statisticsIntelligence - measuring deductive reasoning, cognition, knowledge, memory, logic and rationality Wisdom - measuring self-awareness, common sense, restraint, perception and insight Charisma - measuring force of personality, persuasiveness, leadership and successful planningThese range from about 3 to 20 (depending on the edition).The original attribute sequence in D&D was Strength, Intelligence, Wisdom, Constitution, Dexterity, and Charisma in the original 1974 rules. This listed the three "prime requisites" of the character classes before the "general" stats: strength for fighters, intelligence for magic-users, and wisdom for clerics.
Common types of attribute system:
The attribute sequence in D&D was changed to Strength, Intelligence, Wisdom, Dexterity, Constitution, and Charisma, sometimes referred to as "SIWDCC". This change was made due to the addition of the thief class, which used dexterity as a prime requisite.
The current "SDCIWC" sequence was introduced in AD&D 2nd edition in an attempt to divide physical and cognitive traits into two groups.
Common types of attribute system:
Other games Many other notable games have followed suit while slightly varying the attributes, like Traveller (Strength, Dexterity, Endurance, Intelligence, Education, Social Standing) or like Cortex System games such as the Serenity RPG and the Cortex Plus Leverage with Agility, Alertness, Intelligence, Strength, Vitality, and Willpower.Others use more, some fewer. Tri-Stat dX (including Big Eyes, Small Mouth), as the name would suggest, uses three (Body, Mind, and Soul), whereas a more common division of three, and used in the Cortex Plus game Firefly is Physical, Mental, and Social, but expands with the Storyteller System's attributes.
Common types of attribute system:
SPECIAL is an acronym statistics system developed specifically for the Fallout series, representing the seven attributes used to define Fallout characters: Strength, Perception, Endurance, Charisma, Intelligence, Agility and Luck. SPECIAL is heavily based on GURPS, which was originally intended to be the character system used in the game.
Common types of attribute system:
Some games have used particularly complex systems. For instance, F.A.T.A.L. uses a system of five attributes with four sub-attributes each, resulting in twenty total statistics to roll. This system was criticised for its complexity and for the lack of correlation between related sub-statistics, resulting in oddities such as a character with a higher Average Speech Rate than Maximum Speech Rate.
Common types of attribute system:
Classifications The first three editions of Shadowrun had three separate headings of Physical attributes, Mental Attributes, and Special Attributes, with three stats in each. With the six non-special attributes being Strength, Agility, Body, Charisma, Intelligence, and Willpower, and two of the three special attributes relating to magic and the third being derived, this is arguably a six attribute system.
The Storyteller System used in games like Vampire: The Masquerade took this one step further, breaking the attributes down into three by three classifications. Power, Finesse, and Resistance, and Mental, Physical, and Social, leading to nine different combinations each of which has a separate name with, for example, Mental Finesse being the attribute Wits and Social Resistance being Composure.
Stats and substats Some games think that attributes are not and should not be treated as entirely independent, and therefore make a lot of their attributes dependent on others.
GURPS uses two levels of statistic: four primary statistics (Strength, Dexterity, Intelligence, Health) and four statistics derived directly from those (Fatigue, which defaults to strength or health (depending on edition), Hit Points, which defaults to health or strength (depending on edition), Willpower, which defaults to intelligence, and Speed, which defaults to half the average of health and dexterity.
Hero System 5th edition has eight primary statistics, and a further five derived from them.
Common types of attribute system:
Fitting the setting Some game systems such as those using the Cortex Plus system or those Powered by the Apocalypse work on the basis that the attributes should emphasise elements of the setting thus making them different from game to game even within the same family. So, for example, Dungeon World is meant to resemble a game of D&D so it uses the same statistics as above, whereas Monsterhearts, with its mix of teen drama and paranormal romance uses the statistics Hot, Cold, Violent, and Dark.
Common attribute names:
Attributes are commonly referred to by a three letter abbreviation (Str, Int, etc.).
Hard statistics Hard statistics are those statistics which are generally physical in nature, and are often used to represent physical characteristics of a character.
Strength aka Body, Might, Brawn, Power ...
A measure of how physically strong a character is. Strength often controls the power and/or damage of melee attacks, the maximum weight the character can carry, and sometimes hit points. Armor and weapons might also have a Strength requirement to use them.
Constitution aka Stamina, Endurance, Vitality, Recovery ...
A measure of how sturdy a character is. Constitution often influences hit points, resistances for special types of damage (poisons, illness, heat etc.) and fatigue.
Defense aka Resistance, Resilience, ...
A measure of how resilient a character is. Defense usually decreases taken damage by either a percentage or a fixed amount per hit. Occasionally combined with Constitution.
Dexterity aka Agility, Reflexes, Quickness, ...
A measure of how agile a character is. Dexterity controls attack and movement speed and accuracy, as well as evading an opponent's attack (see Armor Class).
Soft statistics Soft statistics are those statistics which are generally cognitive in nature, and are often used to represent nonphysical characteristics of a character. Alternatively, instead of being mental statistics, they may also represent certain nonphysical effects on a character, as with attributes such as Luck, seen below.
Intelligence aka Intellect, Mind, Knowledge, ...
Common attribute names:
A measure of a character's problem-solving ability. Intelligence often controls a character's ability to comprehend foreign languages and their skill in magic. In some cases, intelligence controls how many skill points the character gets at "level up". In some games, it controls the rate at which experience points are earned, or the amount needed to level up. Under certain circumstances, this skill can also negate combat actions between players and NPC enemies. This is sometimes combined with wisdom and/or willpower.
Common attribute names:
Charisma aka Presence, Charm, Social, ...
A measure of a character's social skills, and sometimes their physical appearance. Charisma generally influences prices while trading and NPC reactions. Under certain circumstances, this skill can negate combat actions between players and NPC enemies.
Wisdom aka Spirit, Wits, Psyche, Sense, ...
A measure of a character's common sense and/or spirituality. Wisdom often controls a character's ability to cast certain spells, communicate to mystical entities, or discern other characters' motives or feelings.
Willpower aka Fortitude, Resolve, Sanity, Personality, Ego, ...
A measure of the character's mental resistance (against pain, fear etc.) when falling victim to mind-altering magic, torture, or insanity. Many games combine willpower and wisdom.
Perception aka Alertness, Awareness, Cautiousness, ...
Common attribute names:
A measure of a character's openness to their surroundings. Perception controls the chance to detect vital clues, traps or hiding enemies, and might influence combat sequence or the accuracy of ranged attacks. Perception-type attributes are more common in more modern games. Note that this skill is usually understood only to apply to what a character can perceive with their established senses (i.e. sight, sound, smell, etc), and does not usually include extrasensory perception or other forms of mental telepathy or telekinesis in the given game unless the character's specific attributes expressly include such abilities (such as the Force in Star Wars). Sometimes combined with wisdom.
Common attribute names:
Luck aka Fate, Chance, ...
A measure of a character's luck. Luck might influence anything, but mostly random items, encounters and outstanding successes/failures (such as critical hits). | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**NephroCheck**
NephroCheck:
NephroCheck is a test that tries to determine the risk of some who is seriously sick developing acute kidney injury. Whether or not the test improves outcomes, however, is unclear as of 2016.NephroCheck tests for the presence of insulin-like growth-factor binding protein 7 (IGFBP7) and tissue inhibitor of metalloproteinases (TIMP-2) in the urine, which are associated with acute kidney injury. The laboratory test was developed by Astute Medical, in San Diego, California. | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**Stericated 6-cubes**
Stericated 6-cubes:
In six-dimensional geometry, a stericated 6-cube is a convex uniform 6-polytope, constructed as a sterication (4th order truncation) of the regular 6-cube.
There are 8 unique sterications for the 6-cube with permutations of truncations, cantellations, and runcinations.
Stericated 6-cube:
Alternate names Small cellated hexeract (Acronym: scox) (Jonathan Bowers) Images
Steritruncated 6-cube:
Alternate names Cellirhombated hexeract (Acronym: catax) (Jonathan Bowers) Images
Stericantellated 6-cube:
Alternate names Cellirhombated hexeract (Acronym: crax) (Jonathan Bowers) Images
Stericantitruncated 6-cube:
Alternate names Celligreatorhombated hexeract (Acronym: cagorx) (Jonathan Bowers) Images
Steriruncinated 6-cube:
Alternate names Celliprismated hexeract (Acronym: copox) (Jonathan Bowers) Images
Steriruncitruncated 6-cube:
Alternate names Celliprismatotruncated hexeract (Acronym: captix) (Jonathan Bowers) Images
Steriruncicantellated 6-cube:
Alternate names Celliprismatorhombated hexeract (Acronym: coprix) (Jonathan Bowers) Images
Steriruncicantitruncated 6-cube:
Alternate names Great cellated hexeract (Acronym: gocax) (Jonathan Bowers) Images
Related polytopes:
These polytopes are from a set of 63 uniform 6-polytopes generated from the B6 Coxeter plane, including the regular 6-cube or 6-orthoplex. | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**Cyazofamid**
Cyazofamid:
Cyazofamid is a fungicide that is highly-specific in controlling oomycete plant pathogens such as Phytophthora infestans, the organism which causes late blight in potato. Its mode of action is thought to involve binding to the Qi center of Coenzyme Q – cytochrome c reductase.Cyazofamid is most often sold under the brand name Ranman.
Synthesis:
Processes to manufacture cyazofamid were disclosed in patents from Ishihara Sangyo Kaisha, Ltd. An acetophenone derivative was first treated with aqueous glyoxal and hydroxylamine to form an oxime-substituted imidazole ring system. This intermediate was treated with thionyl chloride and disulfur dichloride to convert the oxime to a cyano group and chlorinate the imidazole in the position next to the phenyl ring. Finally, treatment with dimethylsulfamoyl chloride gave cyazofamid, with the desired regiochemistry. This placed the sulfamoyl group on the nitrogen adjacent to the phenyl ring rather than the chlorine atom. The structure of the fungicide has been confirmed by X-ray crystallography. | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**MASS syndrome**
MASS syndrome:
MASS syndrome is a medical disorder of the connective tissue similar to Marfan syndrome.
MASS syndrome:
MASS stands for mitral valve prolapse, aortic root diameter at upper limits of normal for body size, stretch marks of the skin, and skeletal conditions similar to Marfan syndrome. It is caused by a mutation in the FBN1 gene, which encodes fibrillin-1. Fibrillin-1 is an extracellular matrix protein that is found in microfibrils; defects in the fibrillin-1 protein cause the malfunctioning of microfibrils, which results in improper stretching of ligaments, blood vessels, and skin.
MASS syndrome:
Treatment options for MASS syndrome are largely determined on a case-by-case basis and generally address the symptoms as opposed to the cause of the disorder. Due to the similarities between MASS syndrome and Marfan syndrome, the treatment plans are also similar.Other possible symptoms are mitral valve prolapse, a large aortic root diameter, and myopia. The skeletal features found in MASS syndrome include curvature of the spine (scoliosis), chest wall deformities, and joint hypermobility.MASS syndrome and Marfan syndrome are overlapping connective tissue disorders. Both can be caused by mutations in the gene encoding a protein called fibrillin. These conditions share many of the same signs and symptoms including long limbs and fingers, chest wall abnormalities (indented chest bone or protruding chest bone), flat feet, scoliosis, mitral valve prolapse, loose or hypextensible joints, highly arched roof of the mouth, and mild dilatation of the aortic root. Unlike in Marfan syndrome, aneurysm does not develop.Individuals with MASS syndrome do not have progressive aortic enlargement or lens dislocation, while people with Marfan syndrome do. Skin involvement in MASS syndrome is typically limited to stretch marks (striae distensae). Also, the skeletal manifestations of MASS syndrome are generally mild. | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**Butabarbital**
Butabarbital:
Butabarbital (brand name Butisol) is a prescription barbiturate sleep aid and anxiety medication. Butabarbital has a particularly fast onset of effects and short duration of action compared to other barbiturates, which makes it useful for certain applications such as treating severe insomnia, relieving general anxiety and relieving anxiety before surgical procedures; however it is also relatively dangerous particularly when combined with alcohol, and so is now rarely used, although it is still prescribed in some Eastern European and South American countries. Its intermediate duration of action gives butabarbital an abuse potential slightly lower than secobarbital. Butabarbital can be hydrolyzed to Valnoctamide.
Butabarbital:
Butabarbital is also sold in combination with belladonna alkaloids under the brand name Butibel. The belladonna is added for antispasmodic effect. This product contains a low dose of butabarbital combined with a standardised mix of belladonna alkaloids and is used as an antispasmodic taken to relieve cramping and spasms of the stomach and intestines. They are used also to decrease the amount of acid formed in the stomach. Another similar product is Donnatal, which contains belladonna alkaloids combined with phenobarbital.
History:
Barbiturates were first discovered to have medical use in 1903, when a research at Bayer showed barbital to be an effective sedative for dogs. It was not until the mid 20th century that the habit forming nature of barbiturates and behavioral side effects were first notedBenzodiazepines are more commonly administered today for their similar sedative and hypnotic properties, and reduced risk of physical dependence. Barbiturate drugs such as butabarbital sodium are used now for short-term and acute treatment under strict doctor supervision only
Clinical uses:
Barbiturates are non-selective depressants of the central nervous system, inducing drowsiness and mild sedative effects. Barbiturate hypnotics are used in the treatment of sleep and anxiety disorders for their calming and sedative properties, however are usually restricted to short term use due to risk of dependency.Butabarbital, most commonly known as Butisol commercially, is an approved Schedule III drug in the US and Canada used in the short-term treatment of anxiety disorders and as a pre-surgical sedative aid. Approved commercial forms are available in tablet or elixir forms. Recently, butabarbital was approved for medical use in 2007 under the brand name Butisol Sodium. Butisol sodium is manufactured by Meda Pharmaceuticals as a Schedule III controlled substance due to its high risk for abuse and dependence.
Clinical uses:
Administration It is most often administered orally as either sodium solution or tablet, however can also be given by intravenous injection. Tablets contain either 30 mg or 50 mg of butabarbital sodium, or 30 mg/5mL with 7% alcohol/vol in solution. For preoperative sedation, adults are administered 50–100 mg 60-90min prior to surgery, with varying doses for pediatric and geriatric patients.
Clinical uses:
Clinical effects & elimination Effects from oral doses often are felt within an hour of administration, lasting somewhere from six to eight hours in effect. A non-selective depressant of the CNS, Butabarbital sodium is used as a sedative hypnotic, depending on dose, to induce drowsiness or sleep, or reduce anxiety and tension. Butabarbital sodium can be used as a pre-surgical anesthetic aid or in the short-term treatment of sleep and anxiety disorders. For short term sleep maintenance and induction butabarbital sodium treatment is recommended to be limited to two weeks, after which it begins to lose efficacy. The half life is approximately 100hrs, eliminated primarily by hepatic microsomal enzymes and excreted in the urine.
Clinical uses:
Overdose & abuse Butabarbital sodium is a Schedule III controlled substance in the US and Canada due to risk of abuse and dependence. A psychoactive substance, butabarbital drugs are often abused with risk of acute intoxication and addiction. Barbiturates such as butabarbital are thought to be habit-forming and addictive, and have severe risks from withdrawal including death. Due to the high risk of dependence and overdose, use of butabarbital is highly regulated and has become less common in clinical application.
Side effects:
Those taking Butabarbital are asked to watch out for signs of severe allergic reaction, such as swelling or difficulty breathing. Less serious side effects include dizziness or drowsiness, excitation, headache, nausea, vomiting, or constipation. Psychiatric disturbances (hallucinations, agitation, confusion, depression, or memory problems), ataxia, difficulty breathing, or slow heartbeat could be signs of serious adverse effects and should be brought to the attention of a doctor immediately.
Side effects:
Adverse effects 1-10% Somnolence<1% Contradictions Those with a hypersensitivity to barbiturates or a history of porphyria should discuss with a doctor before using butisol sodium treatment. Butabarbital has also been shown to interact with some medicines; Talk to your doctor if taking Monoamine oxidase inhibitors (MAOIs), beta-blockers, oral-contraceptives, or other medications, as their efficacy may be affected.At low doses Butabarbital has been shown clinically to induce drowsiness, depressing the sensory cortex and motor activity. In some rare cases Butabarbital has been shown to produce small bursts of excitement or euphoria prior to the sedative effects. Butabarbital is a highly potent drug however, with addictive properties, and small variations in dose can result in significant escalation of effects.
Pharmacology:
Butabarbital is a sedative hypnotic member of the barbiturate family. It is relatively fast acting, with a short duration, producing a range of effects from mild sedation to hypnosis as a function of dosage. An overdose of butabarbital can result in deep coma or even death.
Pharmacology:
Absorption, distribution and excretion Butabarbituates are rapidly distributed and absorbed in the brain, liver and kidneys. One of the more lipophilic barbiturates, butabarbital crosses the blood brain barrier with relative ease, and is slightly more potent then other less lipophilic barbiturates such as phenobarbital. Butabarbital, a weak acid, is most commonly administered orally in its sodium salt form. 3–4 hours after oral administration butabarbital sodium reaches peak plama concentrations of 203 ug/mL for sedation, or 25 ug/mL to induce sleep, absorbed via the GI tract.Once absorbed, butabarbital's effects have a duration of 6–8 hours if orally administered, or 3–6 hours following intravaneous administration. General consensus has it with a half-life of approximately 100hr, however it has also been reported in one study to have a half life of 34-42 hr.The primary way the body terminates activity is by oxidation of radicals at C5, with other biotransformations contributing to a lesser extent. Butabarbital is metabolized almost entirely by the liver, products including polar alcohols, ketones, phenols, or carboxylic acids, before it is renally excreted in the urine.Half-Life: ~100 hr Duration: 6-8 hr Onset: 45-60 min Enzymes induced: CYP1A2, CYP2C9/10, CYP3A4 Excretion: Urine Mechanism of action The mechanism of action by which barbiturates exert their effect is not yet completely understood, however they are believed to be involved in the enhancement of GABA inhibitory neurotransmitter activity in the CNS via GABAA receptors. Butabarbital, as a member of this drug class, acutely potentiates inhibitory GABAergic tone by binding with a specific site associated with a Cl− ionophore at the GABAA receptor. Butabarbital's binding causes the channel to remain open longer and thus prolongs post-synaptic inhibition by GABA. Less well characterized effects of barbiturates include direct inhibition of AMPA-type glutamate receptors, suppressing excitatory glutamatergic neurotransmission. | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**RKI-1447**
RKI-1447:
RKI-1447 is a drug which acts as a potent and selective inhibitor of the enzyme Rho kinase, with an IC50 of 14.5 nM at ROCK1 and 6.2 nM at ROCK2. It has been investigated for applications in cancer treatment, as well as glaucoma, and nonalcoholic fatty liver disease. | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**Scientific Committee on Emerging and Newly Identified Health Risks**
Scientific Committee on Emerging and Newly Identified Health Risks:
The Scientific Committee on Emerging and Newly Identified Health Risks (SCENIHR) is one of the independent scientific committees managed by the Directorate-General for Health and Consumer Protection of the European Commission, which provide scientific advice to the Commission on issues related to consumer products.
Activities:
The SCENIHR provides scientific opinions on questions concerning emerging or newly identified risks on non-food products, as well as on broad, complex or multidisciplinary issues requiring a comprehensive assessment of risks to consumer safety or public health not covered by other risk assessment bodies.
Examples of areas of activity include new technologies (such as nanotechnologies), medical devices, antimicrobial resistance, physical risks (such as noise and electromagnetic fields), and methodologies of risk assessment.
Procedures:
SCENIHR's scientific advisory procedures are based on the principles of scientific excellence, independence and transparency. | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**Construction accounting**
Construction accounting:
Construction accounting is a form of project accounting applied to construction projects. See also production accounting. Construction accounting is a vitally necessary form of accounting, especially when multiple contracts come into play. The construction field uses many terms not used in other forms of accounting, such as "draw" and progress billing. Construction accounting may also need to account for vehicles and equipment, which may or may not be owned by the company as a fixed asset. Construction accounting requires invoicing and vendor payment, more or less as to the amount of business done.In the United States, the authoritative literature on Construction accounting is AICPA Statement of Position SOP 81-1.
Construction accounting:
Construction auditing is an important part of construction accounting and deals with expenses - the IRS offers a guide. IRS Construction Audit Guide . The National Association of Construction Auditors recommends this guide.
Construction Costs:
These are all cost related to the construction process, right from materials, labor costs, consultancy and all management expenses.
Construction accounting involves charging construction costs to the applicable contract. Costs fall into three categories. Direct costs are labor, material, and subcontracting costs, land. Indirect costs include indirect labor, supervision, tools, equipment costs, supplies, insurance, and support costs. Selling, general and administrative costs, are generally excluded from contract costs.
Revenue Recognition:
Construction accounting requires unique revenue recognition rules for contracts in progress.In most cases, revenue is recognized using the Percentage of Completion Method. Under this method, revenue is recognized using an estimate for the overall anticipated profit for a particular contract multiplied by the estimated percent complete of that contract. This involves the inherent risk of relying upon estimates.An example of a Percentage of Completion Method: A construction company has entered into contract to construct a building for $10,000,000. The building was completed in 2020.
Revenue Recognition:
2018 2019 2020 Contract Price $10,000,000 $10,000,000 $10,000,000 Actual cost to date $2,291,000 $6,146,000 $10,211,000 Estimated cost to complete $5,609,000 $4,210,000 $0 Total estimated cost $7,900,000 $10,356,000 $10,211,000 Estimated gross profit (loss) (actual in 2020) $2,100,000 $(356,000) $(211,000) Revenue Recognition: 2018: $2,291,000 / $7,900,000 = 29% * $10,000,000 = $2,900,000 2019: $6,146,000 / $10,356,000 = 59% * $10,000,000 - $2,900,000 = $3,000,000 2020: $10,000,000 - $5,900,000 = $4,100,000 Gross Profit: 2018: $2,900,000 - $2,291,000 = $609,000 2019: $(356,000) - $609,000 = $(956,000) 2020: $(211,000) - $(956,000) - $609,000 = $145,000When using the Percentage of Completion Method you start with the contract price in this example is $10,000,000 for the entire job. The job is to be completed in three years. To record the first years revenue you start with computing the 2018 actual cost to date divided by the total estimated cost to get the percentage of completion for 2018 which is 29% of the job completed in 2018. You than take the 29% multiply by the cost of the job $10,000,000 and you get $2,900,000 of revenue fore 2018. To compute 2019 you take the same steps you take the actual cost to date of $6,146,000 divide it by total estimated cost of $10,356,000 and you get 59%. That is the percentage of the job completed in 2019. Now you take 59% multiply by contract price of $10,000,000 then subtract the previous years revenue of $2,900,000 and 2019 revenue recognized is $3,000,000. For 2020 you take the contract price of $10,000,000 and subtract the total of both previous years revenue which is $5,900,000 to get 2020 completed revenue of $4,100,000. To compute the gross profit for 2018 you take 2018 revenue of $2,900,000 and subtract the actual cost to date of $2,291,000 to get a gross profit of $609,000 for 2018. For 2019 you take the estimated gross profit form the table of $(356,000) subtract the 2018 gross profit total of $609,000 and you get $(956,000) for 2019. 2020 gross profit you take the estimated gross profit from the table of $(211,000) subtract the previous years of $(956,000) and $609,000 and you get $145,000 of gross profit.
Revenue Recognition:
Under SOP 81-1, revenue is also allowed to be computed using the Completed Contract Method. Under this method, contract revenues and costs are not recognized until the contract is substantially complete. However, this method is not allowable if the results are significantly different than results using the Percentage of Completion Method. The Completed Contract Method is allowed in circumstances in which reasonable estimates cannot be determined. However, these types of circumstances can be construed as a lack of internal control. | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**GPR1**
GPR1:
G protein-coupled receptor 1, also known as GPR1, is a protein that in humans is encoded by the GPR1 gene.GPR1 is a member of the G protein-coupled receptor family of transmembrane receptors. It functions as a receptor for chemerin. Other receptors for chemerin include CMKLR1 and CCRL2. | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**Md5deep**
Md5deep:
md5deep is a software package used in the computer security, system administration and computer forensics communities to run large numbers of files through any of several different cryptographic digests. It was originally authored by Jesse Kornblum, at the time a special agent of the Air Force Office of Special Investigations. As of 2017, he still maintains it.
The name md5deep is misleading. Since version 2.0, the md5deep package contains several different programs able to perform MD5, SHA-1, SHA-256, Tiger192 and Whirlpool digests, each of them named by the digest type followed by the word "deep". Thus, the name may confuse some people into thinking it only provides the MD5 algorithm when the package supports many more.
Md5deep:
md5deep can be invoked in several different ways. Typically users operate it recursively, where md5deep walks through one directory at a time giving digests of each file found, and recursing into any subdirectories within. Its recursive behavior is approximately a depth-first search, which has the benefit of presenting files in lexicographical order. On Unix-like systems, similar functionality can be often obtained by combining find with hashing utilities such as md5sum, sha256sum or tthsum.
Md5deep:
md5deep exists for Windows and most Unix-based systems, including OS X. It is present in OS X's Fink, Homebrew and MacPorts projects. Binary packages exist for most free Unix systems. Many vendors initially resist including md5deep as they mistakenly believe its functions can be reproduced with one line of shell scripting. The matching function of the program, however, cannot be done easily in shell.Because md5deep was written by an employee of the U.S. government, on government time, it is in the public domain. Other software surrounding it, such as graphical front-ends, may be copyrighted. | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**Lion taming**
Lion taming:
Lion taming is the taming and training of lions, either for protection or for use in entertainment, such as the circus. The term often applies to the taming and display of lions and other big cats such as tigers, leopards, jaguars, black panthers, cheetahs, and cougars. People often use lion taming as a metaphor for any dangerous activity. Lion taming occurs in zoos around the world to enable the keepers to carry out medical procedures and feedings.
Lion taming:
The Captive Animals Protection Society maintains that animal welfare cannot be guaranteed in circuses.
Notable lion tamers:
In chronological orderGeorge Wombwell (1777–1850), founder of Wombwell's Traveling Menagerie, raised many animals himself, including the first lion bred in captivity in Britain.
Notable lion tamers:
Isaac A. Van Amburgh (1811–1865), American animal trainer who developed the first trained wild animal act in modern times.: 20 He was known for acts of daring, such as placing his head inside the jaws of a wild cat, and became known as “The Lion King.”.: 17 Thomas Macarte (c. 1839–1872), killed during a performance in 1872 Martini Maccomo (c. 1839–1871), a lion tamer in Victorian Britain Carl Hagenbeck (1844–1913), a merchant of wild animals Suresh Biswas (1861–1905), Indian circus performer popular in Europe in the 1880s for taming wild animals Claire Heliot (1866–1953), German woman lion tamer born Klara Haumann (Huth) Tilly Bébé (1879–1932), Austrian lion and polar bear tamer Rose Flanders Bascom (1880–1915), first American female lion tamer Mabel Stark (1889–1968), one of the world's first women tiger tamers Clyde Beatty (1903–1965), one of the pioneers of using a chair in training big cats Irina Bugrimova (1911–2001), the first female lion tamer in Russia Gunther Gebel-Williams (1934–2001), a world-famous animal trainer for the Red Unit with Ringling Bros. and Barnum & Bailey Circus.
Notable lion tamers:
Ángel Cristo (1943–2010), the most famous lion and tiger tamer in Spain, known for his numerous accidents under lion and tiger attacks. In 1982 he won the Medalla de Oro del Festival Internacional del Circo ('Golden Medal of the Circus International Festival').
Martin Lacey, (born 1947), animal trainer, owner of the Great British Circus, trained most of the tigers used in the ESSO TV advertisements in the 1970s.
Martin Lacey Jr., (born 1977), son of Martin, an animal trainer and performer with Circus Krone in Munich | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**Skateboarding sponsorship**
Skateboarding sponsorship:
Skateboarding sponsorship is the commercial sponsorship of an individual or team of people who participate in skateboarding, competitions or public activities. Typically, the individual or team will receive cash payments, reduced-price or free merchandise or equipment from a sponsor in return for public and in-competition use of that sponsor's merchandise or equipment for promotional purposes and recipient testimonial or endorsement. Skateboarding sponsorship may also extend to the sponsorship of major competitions or venues (like specific skateparks) by larger distributors or manufacturers of skateboarding equipment and merchandise.Sponsors employ a variety of methods in an effort to "discover" potential sponsorship recipients including word of mouth, the solicitation of "sponsor-me" videos and direct participation in public skateboarding events and competitions, as well as raising awareness through social media websites.In the United States it is recommended that an organisation wishing to engage with Skateboarders via sponsorship apply to join the IASC. This allows a company to join, take part in and become credible within an already well established industry.
Sponsorship types:
There are two generally recognised classes of individual skateboarding sponsorship. Amateur and Professional. Both can come in different variations and can be agreed contractually in both verbal or written form.
Sponsorship types:
Skate shop sponsorship Skate shop sponsorship is sponsorship by a local professional skateboarding industry retail company. Obligations under the terms of a shop sponsorship vary but are usually light and the rider usually represents the sponsor by wearing branded apparel and by submitting media (videos and photographs) for use in advertising campaigns. Shops commonly employ skateboarders and sponsor their employees. This occurs along with traditional discounts to subsidise pay or as part of an employment agreement. Some simple sponsorship agreements may involve the provision of discounted merchandise or equipment in exchange for a commitment to use that merchandise or equipment at public skate parks or local competitions.Skate shops may sponsor both amateur and professional skateboarders.
Sponsorship types:
Amateur sponsorship Amateur skateboard sponsorship involves the light provision of merchandise and equipment along with the occasional payment of travel and accommodation or living expenses when representing a sponsor in an out of town competition. Amateur skateboarders are not paid to skate and many are too young in any event, as per law.
A sponsored amateur skateboarder may receive some personal promotion as a brand "team member" and will commonly exchange marketing rights to their image for skateboarding equipment and other merchandising and or skateboard products.
Sponsorship types:
Company flow sponsorship Flow sponsorship is similar to shop sponsorship in that it generally involves the sponsorship of an individual by a small to medium commercial skateboard company or enterprise. However, flow sponsorship usually involves the provision of free merchandise (no cost to the sponsored individual) but the offer is not traditionally consistent or long term. Flow sponsorship is seen as one of the first stepping stones of opportunity which an aspiring professional skateboarder might accept on their journey to become pro. And is often used as an incentive before a skateboarder joins a team whilst they are considering all available offers from interested parties. The trade of goods mostly revolves around featuring in print, online and video based media. Personal appearances are rarely part of any agreement and the aim of a flow sponsorship is to give the skateboarder a hand into the industry to help them on to a path involving a career. By 2003, then-6-year-old Mitchie Brusco was committed to 9 such agreements.
Sponsorship types:
Professional company individual sponsorship Professional sponsorship is sponsorship attached to royalty payments and comes with a regular salary in all but the worst of contract formats. Contracts vary but coverage of living expenses which allow the skateboarder to travel and practice to be able to compete on a full-time basis without the need to work full-time, may be factored in. Healthcare, image rights, bonuses, product design and art work licensing are commonly covered in professional skateboarding contracts. Sponsored skateboarders receive monthly packages of sponsored merchandise (including additional merchandise for promotional uses) and equipment (including customized "pro model" equipment) as well as branded clothing and other promotional items which feature the sponsored skater's name or personal logo.
Sponsorship types:
Professional skateboarders may receive royalty payments collected against products sold by their sponsor(s) which display the skateboarder's name or logo.
Sponsorship types:
Traditionally endorsed products are professional grade decks, trucks, clothing, shoes and wheels. It is normal for a rider to primarily attach to a single deck manufacturer as a pro and professional model skateboard products tend to display the professional skateboarder's name prominently in painted or transferred graphics. Deck sponsorship is seen as a primary long term goal and a right of passage by aspiring amateur skateboarders. Obtaining one signifies current prominence within the skateboard industry.
Sponsorship types:
Professional skateboarder Tony Hawk signed endorsement and sponsorship deals with a number of major brands worth up to US$15 million each, including deals with a number of non-skateboarding brands. | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**IEC 63119**
IEC 63119:
IEC 63119 is an international standard defining a protocol for information exchange for electric vehicle charging roaming services, which is currently under development. IEC 63119 is one of the International Electrotechnical Commission's group of standards for electric road vehicles and electric industrial trucks, and is the responsibility of Working Group 9 (WG9) of IEC Technical Committee 69 (TC69).
Standard documents:
IEC 63119 consists of the following parts, detailed in separate IEC 63119 standard documents: IEC 63119-1: General, edition 1 published in 2019.
IEC 63119-2: Use cases IEC 63119-3: Message structure IEC 63119-4: Cybersecurity and information privacy | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**TRPV1**
TRPV1:
The transient receptor potential cation channel subfamily V member 1 (TRPV1), also known as the capsaicin receptor and the vanilloid receptor 1, is a protein that, in humans, is encoded by the TRPV1 gene. It was the first isolated member of the transient receptor potential vanilloid receptor proteins that in turn are a sub-family of the transient receptor potential protein group. This protein is a member of the TRPV group of transient receptor potential family of ion channels. And a receptor being clearly present in bacteria, the oldest organisms on Earth known to express phosphatidylethanolamine, the precursor to endocannabinoids, in their cytoplasmic membranes, and fatty acid metabolites with affinity for this CB receptor are produced by cyanobacteria, which diverged from eukaryotes at least 2000 million years ago (MYA).The function of TRPV1 is detection and regulation of body temperature. In addition, TRPV1 provides a sensation of scalding heat and pain (nociception). In primary afferent sensory neurons, it cooperates with TRPA1 (a chemical irritant receptor) to mediate the detection of noxious environmental stimuli.
Function:
TRPV1 is an element of or mechanism used by the mammalian somatosensory system. It is a nonselective cation channel that may be activated by a wide variety of exogenous and endogenous physical and chemical stimuli. The best-known activators of TRPV1 are: temperature greater than 43 °C (109 °F); acidic conditions; capsaicin (the irritating compound in hot chili peppers); and allyl isothiocyanate, the pungent compound in mustard and wasabi. The activation of TRPV1 leads to a painful, burning sensation. Its endogenous activators include: low pH (acidic conditions), the endocannabinoid anandamide, N-oleyl-dopamine, and N-arachidonoyl-dopamine. TRPV1 receptors are found mainly in the nociceptive neurons of the peripheral nervous system, but they have also been described in many other tissues, including the central nervous system. TRPV1 is involved in the transmission and modulation of pain (nociception), as well as the integration of diverse painful stimuli.
Function:
Sensitization The sensitivity of TRPV1 to noxious stimuli, such as high temperatures, is not static. Upon tissue damage and the consequent inflammation, a number of inflammatory mediators, such as various prostaglandins and bradykinin, are released. These agents increase the sensitivity of nociceptors to noxious stimuli. This manifests as an increased sensitivity to painful stimuli (hyperalgesia) or pain sensation in response to non-painful stimuli (allodynia). Most sensitizing pro-inflammatory agents activate the phospholipase C pathway. Phosphorylation of TRPV1 by protein kinase C have been shown to play a role in sensitization of TRPV1. The cleavage of PIP2 by PLC-beta can result in disinhibition of TRPV1 and, as a consequence, contribute to the sensitivity of TRPV1 to noxious stimuli.
Function:
Desensitization Upon prolonged exposure to capsaicin, TRPV1 activity decreases, a phenomenon called desensitization. Extracellular calcium ions are required for this phenomenon, thus influx of calcium and the consequential increase of intracellular calcium mediate this effect. Various signaling pathways such as phosphorylation by PKA and PKC, interaction with calmodulin, dephosphorylation by calcineurin, and the decrease of PIP2, have been implicated in the regulation of desensitization of TRPV1. Desensitization of TRPV1 is thought to underlie the paradoxical analgesic effect of capsaicin.
Clinical significance:
Peripheral nervous system As a result of its involvement in nociception, TRPV1 has been a target for the development of pain reducers (analgesics). Three major strategies have been used: TRPV1 Use The TRPV1 receptor is useful to be able to measure how an organism can sense temperature change. In the lab the receptor may be removed from mice giving them the inability to detect differences in ambient temperature. In the pharmaceutical field this allows for the blocking of heat receptors giving patients with inflammatory disorders or severe burning pains a chance to heal without the pain. The lack of the TRPV1 receptor gives a glimpse into the developing brain as heat can kill most organisms in large enough doses, so this removal process shows researchers how the inability to sense heat may be detrimental to the survivability of an organism and then translate this to human heat disorders.
Clinical significance:
TRPV1 in immune cells TRPV1 plays an important role not only in neurones but also in immune cells. Activation of TRPV1 modulates immune response including the release of inflammatory cytokines, chemokines, and the ability to phagocytose. However, the role of TRPV1 in immune cells is not entirely understood and it is currently intensely studied. TRPV1 is not the only TRP channel expressed in immune cells. TRPA1, TRPM8 and TRPV4 are the most relevant TRP channels that are also studied in immune cells.The expression of TRPV1 was confirmed in the cells of innate immunity as well as the cells of adaptive immunity. TRPV1 can be found in monocytes, macrophages, dendritic cells, T lymphocytes, natural killer cells and neutrophiles. TRPV1 is said to be potentially very important in immune cell functioning as it senses higher temperature and lower pH, which can affect the immune cell performance.
Clinical significance:
TRPV1 and Adaptive Immunity TRPV1 is an important membrane channel in T cells as it regulates the influx of calcium cations. TRPV1’s involvement is mainly in T cell receptor signalling (TCR) signalling, T cell activation and TCR-mediated influx of calcium ions, but it is involved in T cell cytokine production as well. Indeed, T cells with TRPV1 knockout show impaired calcium uptake after T cell activation via TCR, thus they show dysregulation in signalling pathways such as NF-κB and NFAT.
Clinical significance:
TRPV1 and Innate Immunity Regarding innate immunity, activation of TRPV1 by capsaicin has been shown to suppress the production of nitrite radical, superoxide anion and hydrogen peroxide by macrophages. Furthermore, administration of capsaicin, and subsequent activation of TRPV1, suppresses phagocytosis in dendritic cells. In a mouse model, TRPV1 affect dendritic cell maturation and function, however, further studies are needed to clarify this effect in humans. In neutrophils, the increase in cytosolic calcium cations leads to synthesis of prostaglandins. Activation of TRPV1 by capsaicin modulates neutrophil immune response due to the higher influx of calcium ions into the cell.TRPV1 is also considered a novel therapeutic agent in many inflammatory diseases. Multiple studies have proven that TRPV1 influences the outcome of several inflammatory diseases such as chronic asthma, esophageal inflammation, rheumatoid arthritis and cancer. Studies using TRPV1’s agonists and antagonists have shown that their administration indeed changes the course of inflammation. However, at this point, there is a lot of contradictive evidence about what type of response, pro-inflammatory or anti-inflammatory, TRPV1’s activation induces. Further research needs to be carried out. Meanwhile, it is important to highlight that TRPV1’s influence on inflammatory diseases is probably not limited to only immune cells as it is rather an interplay between immune cells, neurons, and other cell types (epithelial cells etc.).
Clinical significance:
TRPV1 and Cancer TRPV1 was found to be overexpressed in several types of cancers, e.g., pancreatic cancer and colon adenocarcinoma. This suggest that certain types of cancers might be more prone to cell death mediated by capsaicin-induced (and also other vanilloid-induced) cell death. Indeed, studies have shown inversed correlation of consumption of chili-based foods and all-cause mortality along with cancers. This beneficial impact of the consumption of chili-based foods was attributed to capsaicinoid content.TRPV1 activation caused by its agonist capsaicin was shown to induce G0-G1 cell arrest and apoptosis in leukemic cell lines, Adult T-Cell Leukaemia and Multiple Myeloma. Capsaicin reduces the expression of anti-apoptotic protein Bcl-2 and it also promotes activation of p53, a tumour-suppressor protein known as a major regulator of cell death. This effect of capsaicin in both cases subsequently leads to above-mentioned apoptosis.
Clinical significance:
TRPV1 and Neuroinflammation The interplay between neurons and immune cells is a well-known phenomenon. TRPV1 plays its role in neuroinflammation, being expressed both in neurons and in immune cells. Significant importance should be paid to the confirmed expression of TRPV1 in microglia and astrocytes, cells found in close proximity to neurons. The neuro-immune axis is the place of production of neuroinflammatory molecules and receptors that interplay between the two systems and ensure a complex response to external stimuli (or to the body’s own pathologies). Studying TRPV1’s involvement in neuroinflammation has a great therapeutical significance for the future.Cutaneus neurons expressing TRPV1 and dendritic cells were found to be located close to each other. Activation of TRPV1 channels in neurons is associated with subsequent production of interleukin 23 (IL-23) by dendritic cells and further production of IL-17 by T cells. These interleukins are important for host defence against pathogenic fungi (such as Candida albicans) and bacteria (such as Staphylococcus aureus), thus TRPV1’s activation can lead to better defence against these pathogens, thanks to the neuro-immune axis.TRPV1 is said to contribute to autophagy of microglia via its Ca2+-signalling, which leads to mitochondria-induced cell death. The TRPV1 channel also influences microglia-induced inflammation. Migration and chemotaxis of microglia and astrocytes seems to be affected by TRPV1’s interaction with the cytoskeleton and Ca2+-signalling. TRPV1 is therefore involved in the neuro-immune axis via its function in microglia as well.TRPV1 was shown to have protective effect in neurologic disorders such as Huntington’s disease, vascular dementia, and Parkinson’s disease. However, its precise function needs to be further explored.
Ligands:
Antagonists Antagonists block TRPV1 activity, thus reducing pain. Identified antagonists include the competitive antagonist capsazepine and the non-competitive antagonist ruthenium red. These agents could be useful when applied systemically. Numerous TRPV1 antagonists have been developed by pharmaceutical companies. TRPV1 antagonists have shown efficacy in reducing nociception from inflammatory and neuropathic pain models in rats. This provides evidence that TRPV1 is capsaicin's sole receptor. In humans, drugs acting at TRPV1 receptors could be used to treat neuropathic pain associated with multiple sclerosis, chemotherapy, or amputation, as well as pain associated with the inflammatory response of damaged tissue, such as in osteoarthritis.These drugs can affect body temperature (hyperthermia) which is a challenge to therapeutic application. For example, a transient temperature gain (~1 °C for a duration of approximately 40 minutes, reverting to baseline by 40 minutes) was measured in rats with the application of TRPV1 antagonist AMG-9810. The role of TRPV1 in the regulation of body temperature has emerged in the last few years. Based on a number of TRPV-selective antagonists' causing a mild increase in body temperature (hyperthermia), it was proposed that TRPV1 is tonically active in vivo and regulates body temperature by telling the body to "cool itself down". Without these signals, the body overheats. Likewise, this explains the propensity of capsaicin (a TRPV1 agonist) to cause sweating (i.e.: a signal to reduce body temperature). In a recent report, it was found that tonically active TRPV1 channels are present in the viscera and keep an ongoing suppressive effect on body temperature. Recently, it was proposed that predominant function of TRPV1 is body temperature maintenance. Experiments have shown that TRPV1 blockade increases body temperature in multiple species, including rodents and humans, suggesting that TRPV1 is involved in body temperature maintenance. In 2008, AMG-517, a highly selective TRPV1 antagonist was dropped out of clinical trials due to the causation of hyperthermia (~38.3 °C mean increase which was most intense on day 1 but was attenuated on days 2–7. Another molecule, SB-705498, was also evaluated in the clinic but its effect on body temperature was not reported. As we increase understanding of modality specific agonism of TRPV1 it seems that next generation therapeutics targeting TRPV1 have the potential to side-step hyperthermia. Moreover, for at least two indications or approaches this may be a secondary issue. Where the therapeutic approach (e.g., in analgesia) is agonist-mediated desensitization then the hyperthermic effects of antagonists may not be relevant. Secondarily in applications such as TRPV1 antagonism for the treatment of severe conditions such as heart failure, then there may be an acceptable trade-off with mild hyperthermia, although no hyperthermia was observed in rodent models of heart failure treated with BCTC, SB-366791 or AMG-9810. Post translational modification of TRPV1 protein by its phosphorylation is critical for its functionality. Reports published from NIH suggest that Cdk5-mediated phosphorylation of TRPV1 is required for its ligand-induced channel opening.
Ligands:
Agonists TRPV1 is activated by numerous agonists from natural sources. Agonists such as capsaicin and resiniferatoxin activate TRPV1 and, upon prolonged application, cause TRPV1 activity to decrease (desensitization), leading to alleviation of pain via the subsequent decrease in the TRPV1 mediated release of inflammatory molecules following exposures to noxious stimuli. Agonists can be applied locally to the painful area in various forms, generally as a patch or an ointment. Numerous capsaicin-containing creams are available over the counter, containing low concentrations of capsaicin (0.025 - 0.075%). It is debated whether these preparations actually lead to TRPV1 desensitization; it is possible that they act via counter-irritation. Novel preparations containing higher capsaicin concentration (up to 10%) are under clinical trials. Eight percent capsaicin patches have recently become available for clinical use, with supporting evidence demonstrating that a 30-minute treatment can provide up to 3 months analgesia by causing regression of TRPV1-containing neurons in the skin. Currently, these treatments must be re-administered on a regular (albeit infrequent) schedule in order to maintain their analgesic effects.
Ligands:
Cannabinoid ligands Cannabinoid ligands include: Cannabidiol (CBD) - agonist Cannabigerol (CBG) - agonist Tetrahydrocannabivarin (THCV) - agonist Cannabigerovarin (CBGV) - agonist N-Acyl amides N-Acyl Amides that activate cannabimimetic receptors include: Anandamide (AEA) N-Arachidonoyl dopamine N-Oleoyl dopamine N-Arachidonoyl taurine N-Docosahexaenoyl ethanolamine N-Docosahexaenoyl GABA N-Docosahexaenoyl aspartic acid N-Docosahexaenoyl glycine N-Docosahexaenoyl serine N-Arachidonoyl GABA N-Linoleyl GABA Fatty acid metabolites Certain metabolites of polyunsaturated fatty acids have been shown to stimulate cells in a TRPV1-dependent fashion. The metabolites of linoleic acid, including 13(S)-hydroxy-9Z,11E-octadecadienoic acid (13(S)-HODE), 13(R)-hydroxy-9Z,11E-octadecadienoic acid (13(R)-HODE, 9(S)-hydroxy-10(E),12(Z)-octadecadienoic acid (9(S)-HODE), 9(R)-hydroxy-10(E),12(Z)-octadecadienoic acid (9(R)-HODE), and their respective keto analogs, 13-oxoODE and 9-oxoODE (see 13-HODE and 9-HODE sections on Direct actions), activate peripheral and central mouse pain sensing neurons. Reports disagree on the potencies of these metabolites with, for example, the most potent one, 9(S)-HODE, requiring at least 10 micromoles/liter. or a more physiological concentration of 10 nanomoles/liter to activate TRPV1 in rodent neurons. The TRPV1-dependency of these metabolites' activities appears to reflect their direct interaction with TPRV1. Although relatively weak agonists of TRPV1 in comparison to anandamide, these linoleate metabolites have been proposed to act through TRPV1 in mediating pain perception in rodents and to cause injury to airway epithelial cells and thereby to contribute to asthma disease in mice and therefore possibly humans. Certain arachidonic acid metabolites, including 20-hydroxy-5Z,8Z,11Z,14Z-eicosatetraenoic acid (see 20-Hydroxyeicosatetraenoic acid) and 12(S)-hydroperoxy-5Z,8Z,10E,12S,14Z-eicosatetraenoic acid (12(S)-HpETE), 12(S)-hydroxy-5Z,8Z,10E,12S,14Z-eicosatetraenoic acid (12(S)-HETE (see 12-HETE), hepoxilin A3 (i.e. 8R/S-hydroxy-11,12-oxido-5Z,9E,14Z-eicosatrienoic acid) and HxB3 (i.e. 10R/S-hydroxy-11,12-oxido-5Z,8Z,14Z-eicosatrienoic acid) likewise activate TRPV1 and may thereby contribute to tactile hyperalgesia and allodynia (see Hepoxilin#Pain perception).Studies with mice, guinea pig, and human tissues and in guinea pigs indicate that another arachidonic acid metabolite, Prostaglandin E2, operates through its prostaglandin EP3 G protein coupled receptor to trigger cough responses. Its mechanism of action involves activation and/or sensitization of TRPV1 (as well as TRPA1) receptors, presumably by an indirect mechanism. Genetic polymorphism in the EP3 receptor (rs11209716), has been associated with ACE inhibitor-induced cough in humans.Resolvin E1 (RvE1), RvD2 (see resolvins), neuroprotectin D1 (NPD1), and maresin 1 (Mar1) are metabolites of the omega 3 fatty acids, eicosapentaenoic acid (for RvE1) or docosahexaenoic acid (for RvD2, NPD1, and Mar1). These metabolites are members of the specialized proresolving mediators (SPMs) class of metabolites that function to resolve diverse inflammatory reactions and diseases in animal models and, it is proposed, humans. These SPMs also dampen pain perception arising from various inflammation-based causes in animal models. The mechanism behind their pain-dampening effects involves the inhibition of TRPV1, probably (in at least certain cases) by an indirect effect wherein they activate other receptors located on the neurons or nearby microglia or astrocytes. CMKLR1, GPR32, FPR2, and NMDA receptors have been proposed to be the receptors through which these SPMs operate to down-regulate TRPV1 and thereby pain perception.
Ligands:
Fatty acid conjugates N-Arachidonoyl dopamine, an endocannabinoid found in the human CNS, structurally similar to capsaicin, activates the TRPV1 channel with an EC50 of approximately of 50 nM.N-Oleyl-dopamine, another endogenous agonist, binds to human VR1 with an Ki of 36 Nm.Another endocannabinoid anandamide has also been shown to act on TRPV1 receptors.AM404—an active metabolite of paracetamol (also known as acetaminophen) —that serves as an anandamide reuptake inhibitor and COX inhibitor also serves as a potent TRPV1 agonist.The plant-biosynthesized cannabinoid cannabidiol also shows "either direct or indirect activation" of TRPV1 receptors. TRPV1 colocalizes with CB1 receptors and CB2 receptors in sensory and brain neurons respectively, and other plant-cannabinoids like CBN, CBG, CBC, THCV, and CBDV are also agonists of this ion channel. There is also evidence that non cannabinoid components of the Cannabis secondary metabolome such as myrcene activate TRPV1.
Ligands:
Vitamin D metabolites Vitamin D metabolites, calcifediol (25-hydroxy vitamin D or 25OHD) and calcitriol (1,25-hydroxy vitamin D or 1,25OHD), act as endogenous ligands of TRPV1.
Central nervous system TRPV1 is also expressed at high levels in the central nervous system and has been proposed as a target for treatment not only of pain but also for other conditions such as anxiety.
Ligands:
Furthermore, TRPV1 appears to mediate long-term synaptic depression (LTD) in the hippocampus. LTD has been linked to a decrease in the ability to make new memories, unlike its opposite long-term potentiation (LTP), which aids in memory formation. A dynamic pattern of LTD and LTP occurring at many synapses provides a code for memory formation. Long-term depression and subsequent pruning of synapses with reduced activity is an important aspect of memory formation. In rat brain slices, activation of TRPV1 with heat or capsaicin induced LTD while capsazepine blocked capsaicin's ability to induce LTD. In the brainstem (solitary tract nucleus), TRPV1 controls the asynchronous and spontaneous release of glutamate from unmyelinated cranial visceral afferents - release processes that are active at normal temperatures and hence quite distinct from TRPV1 responses in painful heat. Hence, there may be therapeutic potential in modulating TRPV1 in the central nervous system, perhaps as a treatment for epilepsy (TRPV1 is already a target in the peripheral nervous system for pain relief).
Interactions:
TRPV1 has been shown to interact with: CALM1, SNAPAP, and SYT9.
CBD AEA NPR1 PKG
Discovery:
The dorsal root ganglion (DRG) neurons of mammals were known to express a heat-sensitive ion channel that could be activated by capsaicin. The research group of David Julius, therefore, created a cDNA library of genes expressed in dorsal root ganglion neurons, expressed the clones in HEK 293 cells, and looked for cells that respond to capsaicin with calcium influx (which HEK-293 normally do not). After several rounds of screening and dividing the library, a single clone encoding the TRPV1 channel was finally identified in 1997. It was the first TRPV channel to be identified. Julius was awarded the 2021 Nobel prize in Physiology or Medicine for his discovery. | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**Gaboxadol**
Gaboxadol:
Gaboxadol, also known as 4,5,6,7-tetrahydroisoxazolo(5,4-c)pyridin-3-ol (THIP), is a conformationally constrained derivative of the alkaloid muscimol that was first synthesized in 1977 by the Danish chemist Poul Krogsgaard-Larsen. In the early 1980s gaboxadol was the subject of a series of pilot studies that tested its efficacy as an analgesic and anxiolytic, as well as a treatment for tardive dyskinesia, Huntington's disease, Alzheimer's disease, and spasticity. It was not until 1996 that researchers attempted to harness gaboxadol's frequently reported sedative "adverse effect" for the treatment of insomnia, resulting in a series of clinical trials sponsored by Lundbeck and Merck. In March, 2007, Merck and Lundbeck cancelled work on the drug, citing safety concerns and the failure of an efficacy trial. It acts on the GABA system, but in a different way from benzodiazepines, Z-Drugs, and barbiturates. Lundbeck states that gaboxadol also increases deep sleep (stage 4). Unlike benzodiazepines, THIP does not demonstrate reinforcement in mice or baboons despite activation of dopaminergic neurons in the ventral tegmental area.In 2015, Lundbeck sold its rights to the molecule to Ovid Therapeutics, whose plan is to develop it for FXS and Angelman syndrome. It is known internally in Ovid as OV101. | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**Ornithine transcarbamylase deficiency**
Ornithine transcarbamylase deficiency:
Ornithine transcarbamylase deficiency also known as OTC deficiency is the most common urea cycle disorder in humans. Ornithine transcarbamylase, the defective enzyme in this disorder is the final enzyme in the proximal portion of the urea cycle, responsible for converting carbamoyl phosphate and ornithine into citrulline. OTC deficiency is inherited in an X-linked recessive manner, meaning males are more commonly affected than females.
Ornithine transcarbamylase deficiency:
In severely affected individuals, ammonia concentrations increase rapidly causing ataxia, lethargy and death without rapid intervention. OTC deficiency is diagnosed using a combination of clinical findings and biochemical testing, while confirmation is often done using molecular genetics techniques.
Ornithine transcarbamylase deficiency:
Once an individual has been diagnosed, the treatment goal is to avoid precipitating episodes that can cause an increased ammonia concentration. The most common treatment combines a low protein diet with nitrogen scavenging agents. Liver transplant is considered curative for this disease. Experimental trials of gene therapy using adenoviral vectors resulted in the death of one participant, Jesse Gelsinger, and have been discontinued.
Signs and symptoms:
As with several other metabolic conditions, OTC deficiency can have variable presentations, regarding age of onset and the severity of symptoms. This compounded when considering heterozygous females and the possibility of non-random X-inactivation. In the classic and most well-known presentation, a male infant appears well initially, but by the second day of life they are irritable, lethargic and stop feeding. A metabolic encephalopathy develops, and this can progress to coma and death without treatment. Ammonia is only toxic to the brain, other tissues can handle elevated ammonia concentrations without problems.Later onset forms of OTC deficiency can have variable presentations. Although late onset forms of the disease are often considered milder than the classic infantile presentation, any affected individual is at risk for an episode of hyperammonemia that could still be life-threatening, if presented with the appropriate stressors. These patients will often present with headaches, nausea, vomiting, delayed growth and a variety of psychiatric symptoms (confusion, delirium, aggression, or self-injury). A detailed dietary history of an affected individual with undiagnosed OTC deficiency will often reveal a history of protein avoidance.The prognosis of a patient with severe OTC deficiency is well correlated with the length of the hyperammonemic period rather than the degree of hyperammonemia or the presence of other symptoms, such as seizures. Even for patients with late onset forms of the disease, their overall clinical picture is dependent on the extent of hyperammonemia they have experienced, even if it has remained unrecognized.
Genetics:
OTC deficiency is caused by mutations in the OTC gene, which is located on the X chromosome. OTC codes for the mitochondrial enzyme ornithine transcarbamylase, which is expressed only in liver. The functional enzyme consists of three identical subunits. OTC is the last enzyme in the proximal portion of the urea cycle, which consists of the reactions that take place in the mitochondria. The substrates of the reaction catalyzed by ornithine transcarbamylase are ornithine and carbamyl phosphate, while the product is citrulline.There are no common mutations that cause disease, however 10 - 15% of disease causing mutations are deletions. It is inherited in an X-linked recessive manner, meaning males are more commonly affected than females. Females who carry a defective copy of the gene can be severely affected or asymptomatic, largely depending on the random nature of X-inactivation. There is some degree of genotype - phenotype correlation with OTC deficiency, but this depends on a number of situations. Individuals with milder mutations, often associated with late onset disease can still present with severe illness when exposed to sufficient metabolic stress. Correlations are more difficult to ascertain in females, since the residual activity of OTC in the liver is impacted not only by the nature of the mutation, but also by the random pattern of X-inactivation. OTC deficiency is estimated to be the most common urea cycle disorder. An exact incidence is difficult to calculate, due to the varying clinical presentations of later onset forms of the disease. Early estimates of the incidence were as high as 1:14,000 live births, however later studies have decreased these estimates to approximately 1:60,000 - 1:72,000.
Diagnosis:
In individuals with marked hyperammonemia, a urea cycle disorder is usually high on the list of possible causes. While the immediate focus is lowering the patient's ammonia concentrations, identifying the specific cause of increased ammonia levels is key as well.
Diagnosis:
Diagnostic testing for OTC deficiency, or any individual with hyperammonemia involves plasma and urine amino acid analysis, urine organic acid analysis (to identify the presence or absence of orotic acid, as well as rule out an organic acidemia) and plasma acylcarnitines (will be normal in OTC deficiency, but can identify some other causes of hyperammonemia). An individual with untreated OTC deficiency will show decreased citrulline and arginine concentrations (because the enzyme block is proximal to these intermediates) and increased orotic acid. The increased orotic acid concentrations result from the buildup of carbamoyl phosphate. This biochemical phenotype (increased ammonia, low citrulline and increased orotic acid) is classic for OTC deficiency, but can also be seen in neonatal presentations of ornithine aminotransferase deficiency. Only severely affected males consistently demonstrate this classic biochemical phenotype.
Diagnosis:
Heterozygous females can be difficult to diagnose. With the rise of sequencing techniques, molecular testing has become preferred, particularly when the disease causing mutations in the family are known. Historically, heterozygous females were often diagnosed using an allopurinol challenge. In a female with reduced enzyme activity, an oral dose of allopurinol would be metabolized to oxypurinol ribonucleotide, which blocks the pyrimidine biosynthetic pathway. When this induced enzymatic block is combined with reduced physiologic enzyme activity as seen in heterozygotes, the elevation of orotic acid could be used to differentiate heterozygotes from unaffected individuals. This test was not universally effective, as it had both false negative and false positive results.Ornithine transcarbamylase is only expressed in the liver, thus performing an enzyme assay to confirm the diagnosis requires a liver biopsy. Before molecular genetic testing was commonly available, this was one of the only methods for confirmation of a suspected diagnosis. In cases where prenatal diagnosis was requested, a fetal liver biopsy used to be required to confirm if a fetus was affected. Modern molecular techniques have eliminated this need, and gene sequencing is now the preferred method of diagnosis in asymptomatic family members after the diagnosis has been confirmed in a proband.
Treatment:
The treatment goal for individuals affected with OTC deficiency is the avoidance of hyperammonemia. This can be accomplished through a strictly controlled low-protein diet, as well as preventative treatment with nitrogen scavenging agents such as sodium benzoate. The goal is to minimize the nitrogen intake while allowing waste nitrogen to be excreted by alternate pathways. Arginine is typically supplemented as well, in an effort to improve the overall function of the urea cycle. If a hyperammonemic episode occurs, the aim of treatment is to reduce the individual's ammonia levels as soon as possible. In extreme cases, this can involve hemodialysis.Gene therapy had been considered a possibility for curative treatment for OTC deficiency, and clinical trials were taking place at the University of Pennsylvania in the late 1990s. These were halted after the death of Jesse Gelsinger, a young man taking part in a phase I trial using an adenovirus vector. Currently, the only option for curing OTC deficiency is a liver transplant, which restores normal enzyme activity. A 2005 review of 51 patients with OTC deficiency who underwent liver transplant estimated 5-year survival rates of greater than 90%. Severe cases of OTC deficiency are typically evaluated for liver transplant by 6 months of age.
Prognosis:
A 1999 retrospective study of 74 cases of neonatal onset found that 32 (43%) patients died during their first hyperammonemic episode. Of those who survived, less than 20% survived to age 14. Few of these patients received liver transplants. | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**PDLIM3**
PDLIM3:
Actin-associated LIM protein (ALP), also known as PDZ and LIM domain protein 3 is a protein that in humans is encoded by the PDLIM3 gene. ALP is highly expressed in cardiac and skeletal muscle, where it localizes to Z-discs and intercalated discs. ALP functions to enhance the crosslinking of actin by alpha-actinin-2 and also appears to be essential for right ventricular chamber formation and contractile function.
Structure:
ALP exists primarily as two alternatively spliced variants; a 39.2 kDa (364 amino acids) protein in skeletal muscle and a 34.3 kDa (316 amino acids) protein in cardiac muscle and smooth muscle. ALP has a N-terminal PDZ domain and a C-terminal LIM domain. In addition, the ALP subfamily contains a specific 34 amino acid domain named the ALP-like motif, containing protein kinase C consensus sequences. The PDZ domain of ALP binds to alpha actinin-2, specifically to its spectrin-like repeats. The PDZ domain is a motif composed of 80-120 amino acids with conserved four residue GLGF sequences that typically interact with C-termini of cytoskeletal proteins. The region of heterogeneity in the two isoforms is between the PDZ domain and LIM domain. ALP is localized to chromosome 4q35. It has been shown that deletion of muscleblind-like 1 in mice can alter the splicing pattern of PDLIM3.
Function:
Studies have shown that ALP is present at the first stage of myofibrilogenesis where it is bound to alpha actinin-2, and this association remains intact in mature myofibrils where ALP is localized to Z-discs and intercalated discs. Alpha actinin-2 is however not required for targeting ALP to Z-lines. Studies in ALP knockout mice have shown that ALP facilitates the cross-linking of actin filaments by alpha actinin-2, and absence of ALP induces abnormal right ventricular chamber formation, dysplasia and cardiomyopathy. Further studies using right ventricular epicardial systolic strain and geometric remodeling analysis in these animals unveiled that absence of ALP diminishes right ventricular contractile function and alters the pattern of cardiac hypertrophic remodeling. Two studies using integrative genomic approaches to investigate genetic modifiers of collagen deposition or intrinsic aerobic running capacity (ARC) have mapped PDLIM3 to respective quantitative trait loci, suggesting that ALP may be involved in molecular networks related to these cardiac phenomena.
Clinical significance:
Chromosome 4 pericentric inversion has been observed in 10 patients, with associated cardiac defects linked to terminal 4q35.1 deletions, which may affect PDLIM3. | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**Coaching psychology**
Coaching psychology:
Coaching psychology is a field of applied psychology that applies psychological theories and concepts to the practice of coaching. Its aim is to increase performance, self-actualization, achievement and well-being in individuals, teams and organisations by utilising evidence-based methods grounded in scientific research. Coaching psychology is influenced by theories in various psychological fields, such as humanistic psychology, positive psychology, learning theory and social psychology.
Coaching psychology:
Coaching psychology formally began as psychological sub-discipline in 2000 when the first "coaching psychology" course was offered at the University of Sydney. Since then, learned societies dedicated to coaching psychology have been formed, and peer-reviewed journals publish research in coaching psychology. Applications of coaching psychology range from athletic and educational coaching to leadership and corporate coaching.
History:
Early history Early applications of psychological theory and practice to coaching (in particular, athletic coaching) can be traced to the 1920s. In 1926, Coleman Griffith published The Psychology of Coaching: A Study of Coaching Methods in the Point of View of Psychology. Based on observations of football and basketball teams, Griffith discussed a wide variety of aspects of coaching such as spectator effects, over-coaching problems, principles of learning. Griffith has been noted as "America's first sport psychologist" and a pioneer applying the science of psychology to coaching. Years later, more texts on coaching psychology began to emerge. In 1951, John Lawther of Penn State University published Psychology of Coaching. The earliest book in WorldCat with the term "coaching psychology" in the title is Modern Coaching Psychology by Curtiss Gaylord, published in 1967.
History:
21st century Despite these early developments, contemporary coaching psychology was only formally established at the beginning of the 21st century. In January 2000, Anthony Grant implemented the first "coaching psychology" unit of study at the University of Sydney and his doctoral dissertation set the stage for further research to establish the field of coaching psychology as an evidence-based discipline. Many coaching psychologists consider Grant as a pioneer in the field.
History:
Further development began in 2006 when the Australian Psychological Society (APS) held a conference that founded the Interest Group in Coaching Psychology (IGCP). Outside Australia, Stephen Palmer of the British Psychological Society (BPS) formed the Special Group in Coaching Psychology (SGCP). Both the IGCP and the SGCP aimed to further develop the profession of coaching psychology in terms of theory and application by providing a platform for sharing relevant research and experiences among coaching psychologists. Since the establishment of the IGCP and SGCP, more international societies dedicated to coaching psychology have been established in Europe, the Middle East and South Africa. On December 18, 2006, the International Society for Coaching Psychology (ISCP) was founded in order to promote the international development of the field.Currently, there are a number of peer-reviewed journals dedicated to literature and research on coaching psychology. For instance, The Coaching Psychologist (since 2005) is provided by the SGCP. The IGCP and IGCP jointly publish the International Coaching Psychology Review (since 2006). Coaching Psychology International (since 2009) is published by International Society of Coaching Psychology.
Theoretical influences:
Humanistic psychology The humanistic approach to psychology is regarded as a large contributor to coaching psychology. Both humanistic and coaching psychology share the common view of the human as self-actualising. That is, whenever given the opportunity, humans will seize the capacity to improve themselves. Coaching psychology looks at this development as a process consisting of concrete positive changes in one's life. Furthermore, this process of growth is undertaken by both the client and the coach who facilitates self-actualisation in their clients.In Carl Rogers' person-centered therapy, the client-therapist relationship is a key element in facilitating growth. Thus, the relationship between the coach (the facilitator) and the client (the learner) is crucial. In particular, Rogers identified three key qualities in a good coach-client relationship: "realness" (genuineness), trust, and empathetic understanding. Additionally, an important distinction is made between working on the client and working with the client. A coach must be willing to collaborate and actively engage with the client in order to understand their experiences and make choices that promote growth. When this is achieved, the coach-client relationship becomes an active partnership.Additionally, according to Rogers, growth in a client is attained through unconditional positive regard. Coaches must empathise with their clients in order to understand their experiences and viewpoints. To achieve this, the coach must be able to understand their clients not only on an intellectual level, but also on an emotional level. Along with empathy, coaches must be able to accept their clients for who they really are since individuals need to feel valued for their "true selves" in order to self-actualise.
Theoretical influences:
Positive psychology Positive psychology (developed by Martin Seligman and others) dwells on the positive aspects of human characteristics such as strength and competency. At its core, coaching psychology shares this focus; effective coaching entails improving the performance and well-being of the client. Positive psychology thus provides a foundation for coaching. Coaching psychology has been considered a type of applied positive psychology.Positive emotions motivate individuals to enhance their abilities and competencies. The broaden-and-build theory by Barbara Fredrickson posits that positive emotions can play a role in sparking not just motivation, but also actions that are productive and beneficial. In coaching, encouraging positive emotions is emphasised in order to inspire clients to take concrete action towards their goals.Aside from emotions, full engagement in activity is also a factor in maximising one's performance. Mihaly Csikszentmihalyi described this level of maximal involvement in a task as flow. In other words, individuals experiencing flow are "in the zone". Coaches play a role in setting an environment that induces flow. This can be achieved through clear and consistent goal-setting. Providing clear and immediate feedback also keeps the client informed about whether their actions are helping achieve their goals. Coaches also help strike a balance between challenge and skills as tasks that are too easy or too difficult for the client may hinder goal-achievement.
Theoretical influences:
Theories of learning Operant conditioning (as described by B. F. Skinner) views learning as a process involving reinforcement and punishment. Coaches are encouraged to always reinforce healthy and productive behaviours through verbal reinforcement, such as motivational words and images. Intrinsic reinforcement (i.e. reinforcement from within the individual) can also play a huge role in improving performance and encouraging goal-directed action. Though punishment can direct clients towards desired behaviours, performance may be hindered by unwarranted side effects, such as anxiety and resentment towards the coach.David A. Kolb's experiential learning theory posits that individuals learn through their experiences. Experiential learning is facilitated by self-reflection, self-assessment and action. Coaches can encourage critical self-reflection of experiences through "coaching logs" wherein coachees analyse their thoughts and emotions in various incidents and circumstances. This helps clients examine and challenge their own beliefs, attitudes and behaviours. Insight gained from this aids in transformative learning where trainees develop an action plan for further self-improvement and increased performance based on their own experiences.
Theoretical influences:
Lev Vygotsky described the zone of proximal development (ZPD) as a space between what a person knows (an action that can be performed easily) and what a person doesn't know (what is considered difficult). Vygotsky theorised that learning is most effective within this zone. Coaches facilitate effective learning by providing coachees with activities within the ZPD, which are neither too easy nor too challenging (this is a process called scaffolding).Social learning theory also influenced coaching psychology. According to Albert Bandura, observational learning occurs when individuals learn from the people around them (called models). Coaches should be aware of their coachee's models as this can shape their attitudes and behaviour. Additionally, coaches should assess factors affecting observational learning in their trainees, such as attention and the frequency of the observed behaviour.
Theoretical influences:
Other influences Gestalt theory explains that people perceive events around us in a way that conforms to their personal ideas, beliefs and experiences. Coachees must be guided in their awareness of their own attitudes and experiences, which shape their perception of the world. Concepts in social psychology such as interpersonal influence and compliance emphasise the powerful role that social interactions play in shaping thinking, performance, and behaviour in coachees. Cultural psychology assists coaches in facilitating growth and learning in clients from various cultural backgrounds. Study of psychopathology may also be important in developing the proper methods of coaching for mentally unhealthy individuals.
Models:
Coaching psychology has a large number of models and frameworks derived from psychological theories and evidence. These models are used in order to guide the practice of coaching psychology and to ensure that coaching is informed by scientifically-proven concepts.
GROW The GROW model is considered one of the most popular behavioural coaching models. Its four stages outline the process of problem-solving, goal-setting and improvement of performance. The name of each stage varies slightly depending on the source.
Models:
PRACTICE Stephen Palmer developed the PRACTICE model as a guide to problem-solving and solution-seeking. The issues are identified during first stage is Problem identification. Next, Realistic goals are developed with regards to the issues. Afterwards, Alternate solutions that work towards the goals are brainstormed. The possible outcomes of the solutions are then critically evaluated during the Consideration of consequences. Following this, the best options are chosen during Targeting the most feasible solution(s). Then comes the Implementation of the Chosen solution(s). The final step is the Evaluation where coaches and coachees discuss the effectiveness of the solution and any lessons learned from the experience.
Models:
SPACE The SPACE model is a bio-psycho-social framework based on cognitive-behavioural psychology. Its purpose is to guide the coach in assessing and understanding the behaviour of their clients during specific situations. SPACE is an acronym that stands for Social context, Physiology, Action, Cognition and Emotion. It can be further subdivided into smaller frameworks: ACE and PACE. The ACE framework examines the relationships between the action, emotions and cognitions of the individual. The PACE framework then takes the ACE model and considers the physiological or biological response that accompanies cognitions, emotions and behaviour. Finally, the main SPACE model takes into account the social context in which the behaviour occurs.
Models:
Other models Other approaches such as the ABCDE cognitive model for problem-solving have been developed. The OSKAR, ACHIEVE and POSITIVE models stem from the GROW model that focuses on goal-setting, solution-seeking, as well as nurturing coaching relationship. For leadership coaching, LASER (which stands for Learning, Assessing, Story-making, Enabling and Reframing) outlines a five-step process for effective coaching. The transtheoretical model of change (developed by James O. Prochaska and others) and appreciative inquiry focus on understanding the process of change and encouraging clients to act towards positive change.
Applications:
Athlete coaching Coaching psychology influences training methods for athlete development. It aims not only to improve performance in sports, but also to develop athletes holistically. Thus, factors affecting development such as athlete motivation have been studied through cognitive, social and emotional theories. One study found that athlete narcissism impacts the effectiveness of performance expectations set by the coach. Physical and mental skill enhancement are also studied with cognitive-behavioural theories. Research has shown that effective goal-setting improves performance in sport. Additionally, self-efficacy is also an important factor affecting athlete development. Thus, coaches are encouraged to increase self-efficacy in athletes through positive feedback and being a model of self-confidence themselves. Even coaches' own beliefs about their skill level in coaching affect the development of self-efficacy in athletes.
Applications:
In education Coaching psychology can also be applied in schools. It examines the most effective ways of educating students grounded in psychological theory. For instance, theories on motivation focus on the effects of self-efficacy and motivation on student performance. Improving teacher confidence and self-efficacy is also an area of study for coaching psychologists. Coaching psychology also guides students, teachers and staff in effective goal-setting and goal-attainment. Additionally, coaching methods like reciprocal peer coaching (the process of teachers evaluating each other's performance) are encouraged because they cultivate support and trust among educators. Peer coaching in the classroom also provides a collaborative environment for students, which is conducive for learning. | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**Peer to Peer Remote Copy**
Peer to Peer Remote Copy:
Peer to Peer Remote Copy or PPRC is a protocol to replicate a storage volume to another control unit in a remote site. Synchronous PPRC causes each write to the primary volume to be performed to the secondary as well, and the I/O is only considered complete when update to both primary and secondary have completed. Asynchronous PPRC will flag tracks on the primary to be duplicated to the secondary when time permits.
Peer to Peer Remote Copy:
PPRC is also the name IBM calls their implementation of the protocol for their storage hardware. Other vendors have their own implementation. For example, the HDS implementation is called TrueCopy. EMC also provides a similar capability on their VPLEX platforms called "MirrorView".
PPRC can be used to provide very fast data recovery due to failure of the primary site.
In IBM zSeries computers with two direct access storage device (DASD) control units connected through dedicated connections, PPRC is the protocol used to mirror a DASD volume in one control unit (the primary) to a DASD volume in the other control unit (the secondary).
In the IBM SAN Volume Controller PPRC is used to mirror a virtualized storage volume to remote (or the same) cluster.
PPRC is also referred to as Metro Mirror when comparing to Global Mirror. | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**ORiNOCO**
ORiNOCO:
ORiNOCO was the brand name for a family of wireless networking technology by Proxim Wireless (previously Lucent). These integrated circuits (codenamed Hermes) provide wireless connectivity for 802.11-compliant Wireless LANs.
Variants:
Lucent offered several variants of the PC Card, referred to by different color-based monikers: White/Bronze: WaveLAN IEEE Standard 2 Mbit/s PC Cards with 802.11 support.
Silver: WaveLAN IEEE Turbo 11 Mbit/s PC Cards with 802.11b and 64-bit WEP support.
Gold: WaveLAN IEEE Turbo 11 Mbit/s PC Cards with 802.11b and 128-bit WEP support.Later models dropped the 'Turbo' moniker due to 802.11b 11 Mbit/s becoming widespread.
Proxim, after taking over Lucent's wireless division, rebranded all their wireless cards to ORiNOCO - even cards not based on Lucent/Agere's Hermes chipset. Proxim still offers ORiNOCO-based cards under the 'Classic' brand.
Rebranded products:
The WaveLAN chipsets that power ORiNOCO-branded cards were commonly used to power other wireless networking devices, and are compatible with a number of other access points, routers and wireless cards. The following brand and models utilise the chipset, or are rebrands of an ORiNOCO product: 3Com AirConnect Apple AirPort and AirMac cards (original only, not AirPort Extreme). Modified to remove the antenna stub.
Rebranded products:
AVAYA World Card Cabletron RoamAbout 802.11 DS Compaq WL100 11 Mbit/s Wireless Adapter D-Link DWL-650 ELSA AirLancer MC-11 Enterasys RoamAbout Ericsson WLAN Card C11 Farallon SkyLINE Fujitsu RoomWave HyperLink Wireless PC Card 11Mbit/s Intel PRO/Wireless 2011 Lucent Technologies WaveLAN/IEEE Orinoco Melco WLI-PCM-L11 Microsoft Wireless Notebook Adapter MN-520 NCR WaveLAN/IEEE Adapter Proxim LAN PC CARD HARMONY 80211B Samsung 11Mbit/s WLAN Card Symbol LA4111 Spectrum24 Wireless LAN PC Card Toshiba Wireless LAN Mini PCI Card
Preferred wireless chipset for wardriving:
The ORiNOCO (and their derivatives) is preferred by wardrivers, due to their high sensitivity and the ability to report the level of noise (something that other chips do not report). The pre-Proxim (or 'Classic') ORiNOCO cards have a jack for attaching an external antenna.
Linux drivers:
A Linux Orinoco Driver supports the IEEE 802.11b Hermes/ORiNOCO family of chips. It was included in the Linux kernel since version 2.4.3. | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**Locally convex vector lattice**
Locally convex vector lattice:
In mathematics, specifically in order theory and functional analysis, a locally convex vector lattice (LCVL) is a topological vector lattice that is also a locally convex space. LCVLs are important in the theory of topological vector lattices.
Lattice semi-norms:
The Minkowski functional of a convex, absorbing, and solid set is a called a lattice semi-norm. Equivalently, it is a semi-norm p such that |y|≤|x| implies p(y)≤p(x).
The topology of a locally convex vector lattice is generated by the family of all continuous lattice semi-norms.
Properties:
Every locally convex vector lattice possesses a neighborhood base at the origin consisting of convex balanced solid absorbing sets.The strong dual of a locally convex vector lattice X is an order complete locally convex vector lattice (under its canonical order) and it is a solid subspace of the order dual of X ; moreover, if X is a barreled space then the continuous dual space of X is a band in the order dual of X and the strong dual of X is a complete locally convex TVS.If a locally convex vector lattice is barreled then its strong dual space is complete (this is not necessarily true if the space is merely a locally convex barreled space but not a locally convex vector lattice).If a locally convex vector lattice X is semi-reflexive then it is order complete and Xb (that is, (X,b(X,X′)) ) is a complete TVS; moreover, if in addition every positive linear functional on X is continuous then X is of X is of minimal type, the order topology τO on X is equal to the Mackey topology τ(X,X′), and (X,τO) is reflexive. Every reflexive locally convex vector lattice is order complete and a complete locally convex TVS whose strong dual is a barreled reflexive locally convex TVS that can be identified under the canonical evaluation map with the strong bidual (that is, the strong dual of the strong dual).If a locally convex vector lattice X is an infrabarreled TVS then it can be identified under the evaluation map with a topological vector sublattice of its strong bidual, which is an order complete locally convex vector lattice under its canonical order.If X is a separable metrizable locally convex ordered topological vector space whose positive cone C is a complete and total subset of X, then the set of quasi-interior points of C is dense in C.
Properties:
If (X,τ) is a locally convex vector lattice that is bornological and sequentially complete, then there exists a family of compact spaces (Xα)α∈A and a family of A -indexed vector lattice embeddings fα:CR(Kα)→X such that τ is the finest locally convex topology on X making each fα continuous.
Examples:
Every Banach lattice, normed lattice, and Fréchet lattice is a locally convex vector lattice. | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**V Pay**
V Pay:
V Pay was a Single Euro Payments Area (SEPA) debit card for use in Europe, issued by Visa Europe. It used the EMV chip and PIN system and could be co-branded with various national debit card schemes such as the German Girocard or Italy's PagoBancomat.
Overview:
The V Pay debit card system competes with the Mastercard Maestro debit card product. However, unlike Mastercard Maestro, V Pay cards cannot be used in non-EMV environments, limiting its acceptance to those countries and merchants that use this system. Also unlike Mastercard Maestro, which is issued and accepted globally, V Pay is designed as a specifically European product, and is not issued or accepted outside European countries except for some of their overseas territories. However, some cards are co-branded with the Visa Electron system, which allows using them outside Europe.V Pay cards began to be accepted at merchants in France and Greece in 2005, and acceptance had since expanded to more European countries. However from 2019, the V Pay system is gradually phased-out in favor of Visa Debit. | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**Greater palatine foramen**
Greater palatine foramen:
At either posterior angle of the hard palate is the greater palatine foramen, for the transmission of the descending palatine vessels and greater palatine nerve; and running anteriorly (forward) and medially (towards the center-line) from it is a groove, for the same vessels and nerve.
Variations:
The greater palatine foramen (GPF) is related to the upper 3rd molar tooth in most of the skulls (55%), 2nd molar in (12%), between the 2nd and 3rd molar in (19%) and retromolar in (14%). The shape of the foramen is elongated antero-posteriorly; however, an unusually crescent shaped foramen is rare. | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**Direct digital synthesis**
Direct digital synthesis:
Direct digital synthesis (DDS) is a method employed by frequency synthesizers used for creating arbitrary waveforms from a single, fixed-frequency reference clock. DDS is used in applications such as signal generation, local oscillators in communication systems, function generators, mixers, modulators, sound synthesizers and as part of a digital phase-locked loop.
Overview:
A basic Direct Digital Synthesizer consists of a frequency reference (often a crystal or SAW oscillator), a numerically controlled oscillator (NCO) and a digital-to-analog converter (DAC) as shown in Figure 1.
Overview:
The reference oscillator provides a stable time base for the system and determines the frequency accuracy of the DDS. It provides the clock to the NCO, which produces at its output a discrete-time, quantized version of the desired output waveform (often a sinusoid) whose period is controlled by the digital word contained in the Frequency Control Register. The sampled, digital waveform is converted to an analog waveform by the DAC. The output reconstruction filter rejects the spectral replicas produced by the zero-order hold inherent in the analog conversion process.
Performance:
A DDS has many advantages over its analog counterpart, the phase-locked loop (PLL), including much better frequency agility, improved phase noise, and precise control of the output phase across frequency switching transitions. Disadvantages include spurious responses mainly due to truncation effects in the NCO, crossing spurs resulting from high order (>1) Nyquist images, and a higher noise floor at large frequency offsets due mainly to the digital-to-analog converter.Because a DDS is a sampled system, in addition to the desired waveform at output frequency Fout, Nyquist images are also generated (the primary image is at Fclk-Fout, where Fclk is the reference clock frequency). In order to reject these undesired images, a DDS is generally used in conjunction with an analog reconstruction lowpass filter as shown in Figure 1.
Performance:
Frequency agility The output frequency of a DDS is determined by the value stored in the frequency control register (FCR) (see Fig.1), which in turn controls the NCO's phase accumulator step size. Because the NCO operates in the discrete-time domain, it changes frequency instantaneously at the clock edge coincident with a change in the value stored in the FCR. The DDS output frequency settling time is determined mainly by the phase response of the reconstruction filter. An ideal reconstruction filter with a linear phase response (meaning the output is simply a delayed version of the input signal) would allow instantaneous frequency response at its output because a linear system can not create frequencies not present at its input.
Performance:
Phase noise and jitter The superior close-in phase noise performance of a DDS stems from the fact that it is a feed-forward system. In a traditional phase locked loop (PLL), the frequency divider in the feedback path acts to multiply the phase noise of the reference oscillator and, within the PLL loop bandwidth, impresses this excess noise onto the VCO output. A DDS, on the other hand, reduces the reference clock phase noise by the ratio fclk/fo because the fractional division of the clock derives its output. Reference clock jitter translates directly to the output, but this jitter is a smaller percentage of the output period (by the ratio above). Since the maximum output frequency is limited to fclk/2 , the output phase noise at close-in offsets is always at least 6dB below the reference clock phase noise.At offsets far removed from the carrier, the phase-noise floor of a DDS is determined by the power sum of the DAC quantization noise floor and the reference clock phase noise floor.
External links and further reading:
Tutorial on Digital Signal Synthesis (From Analog Devices) L. Cordesses, "Direct Digital Synthesis: A Tool for Periodic Wave Generation (Part 1)" IEEE Signal Processing Magazine, DSP Tips & Tricks column, pp. 50–54, Vol. 21, No. 4 July 2004.
L. Cordesses, Direct Digital Synthesis: A Tool for Periodic Wave Generation (Part 2) IEEE Signal Processing Magazine, DSP Tips & Tricks column, pp. 110–117, Vol. 21, No. 5, Sep. 2004.
Jouko Vankka & Kari A.I. Halonen (2010). Direct Digital Synthesizers: Theory, Design and Applications. The Kluwer international series in Engineering and Computer Science. Boston, MA: Kluwer Academic Publishers. ISBN 978-1-4419-4895-3. | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**Constant-force spring**
Constant-force spring:
An ideal constant-force spring is a spring for which the force it exerts over its range of motion is a constant, that is, it does not obey Hooke's law. In reality, "constant-force springs" do not provide a truly constant force and are constructed from materials which do obey Hooke's law.
Generally constant-force springs are constructed as a rolled ribbon of spring steel such that the spring is in a rolled up form when relaxed.
Constant-force spring:
As the spring is unrolled, the material coming off the roll (un)bends from the radius of the roll into a straight line between the reel and the load. Because the material tension-stiffness of the straight section is orders of magnitude greater than the bending stiffness of the ribbon, the straight section does not stretch significantly, the restoring force comes primarily from the deformation of the portion of the ribbon near the roll. Because the geometry of that region remains nearly constant as the spring unrolls (with material coming off the roll joining the curved section, and material in the curved section joining the straight section), the resulting force is nearly constant. | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**O-823**
O-823:
O-823 is a drug which is a cannabinoid derivative that is used in scientific research. It is described as a mixed agonist/antagonist at the cannabinoid receptor CB1, meaning that it acts as an antagonist when co-administered alongside a more potent CB1 agonist, but exhibits weak partial agonist effects when administered by itself. | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**Symbiosis in lichens**
Symbiosis in lichens:
Symbiosis in lichens is the mutually beneficial symbiotic relationship of green algae and/or blue-green algae (cyanobacteria) living among filaments of a fungus, forming lichen.Living as a symbiont in a lichen appears to be a successful way for a fungus to derive essential nutrients, as about 20% of all fungal species have adopted this mode of life. The autotrophic symbionts occurring in lichens are a wide variety of simple, photosynthetic organisms commonly and traditionally known as “algae”. These symbionts include both prokaryotic and eukaryotic organisms.
Overview of lichens:
"Lichens are fungi that have discovered agriculture" — Trevor GowardA lichen is a combination of fungus and/or algae and/or cyanobacteria that has a very different form (morphology), physiology, and biochemistry than any of the constituent species growing separately. The algae or cyanobacteria benefit their fungal partner by producing organic carbon compounds through photosynthesis. In return, the fungal partner benefits the algae or cyanobacteria by protecting them from the environment by its filaments, which also gather moisture and nutrients from the environment, and (usually) provide an anchor to it.The majority of the lichens contain eukaryotic autotrophs belonging to the Chlorophyta (green algae) or to the Xanthophyta (yellow-green algae). About 90% of all known lichens have a green alga as a symbiont. Among these, Trebouxia is the most common genus, occurring in about 20% of all lichens. The second most commonly represented green alga genus is Trentepohlia. Overall, about 100 species are known to occur as autotrophs in lichens. All the algae and cyanobacteria are believed to be able to survive separately, as well as within the lichen; that is, at present no algae or cyanobacteria are known which can only survive naturally as part of a lichen. Common algal partners are Trebouxia, Pseudotrebouxia, or Myrmecia.The prokaryotes belong to the Cyanobacteria, which are often called by their old name “bluegreen algae”. Cyanobacteria occur as symbionts only in about 8% of known lichens. The most commonly occurring genera of symbiotic cyanobacteria are Nostoc and Scytonema.
Overview of lichens:
Nomenclature Both the and the fungus partner bear the same scientific name, and the lichens are being integrated into the classification schemes for fungi. Depending on context, the taxonomic name can be meant to refer to the entire lichen, or just the fungus that is part of the lichen.
The alga or cyanobacterium bears its own scientific name, which has no relationship to either the name of the lichen or the fungus.
Fungus component:
About 20% of all fungal species are able to form lichens. The fungal partner may be an Ascomycete or Basidiomycete. Overall, about 98% of lichens have an ascomycetous mycobiont. Next to the Ascomycota, the largest number of lichenized fungi occur in the unassigned fungi imperfecti. Comparatively few basidiomycetes are lichenized, but these include agarics, such as species of Lichenomphalia, clavarioid fungi, such as species of Multiclavula, and corticioid fungi, such as species of Dictyonema.
Fungus component:
The largest number of lichenized fungi occur in the Ascomycota, with about 40% of species forming such an association. Some of these lichenized fungi occur in orders with nonlichenized fungi that live as saprotrophs or plant parasites (for example, the Leotiales, Dothideales, and Pezizales).
Other lichen fungi occur in only five orders in which all members are engaged in this habit (Orders Graphidales, Gyalectales, Peltigerales, Pertusariales, and Teloschistales). Lichenized and nonlichenized fungi can even be found in the same genus or species.
Photosynthetic component:
The photosynthetic component of a lichen is called the photobiont or phycobiont. The layer of tissue containing the cells of the photobiont is called the “photobiontic layer”.Approximately 100 species of photosynthetic partners from 40 genera and 5 distinct classes (prokaryotic: Cyanophyceae; eukaryotic: Trebouxiophyceae, Phaeophyceae, Chlorophyceae) have been found to associate with the lichen-forming fungi.A particular fungus species and algal species are not necessarily always associated together in a lichen. One fungus, for example, can form lichens with a variety of different algae. The thalli produced by a given fungal symbiont with its differing partners will be similar, and the secondary metabolites identical, indicating that the fungus has the dominant role in determining the morphology of the lichen. Further, the same algal species can occur in association with different fungal partners. Lichens are known in which there is one fungus associated with two or even three algal species. Rarely, the reverse can occur, and two or more fungal species can interact to form the same lichen.
Photosynthetic component:
Green algae About 90% of all known lichens have a green alga as a symbiont. 'Chlorococcoid' means a green alga (Chlorophyta) that has single cells that are globose, which is common in lichens. This was once placed in the order Chlorococcales, but new DNA data shows many independent lines of evolution exist among this formerly large taxonomic group. Chlorococcales is now a relatively small order and may no longer include any lichen photobionts. The term 'Trebouxioid' refers to green algal photobionts in the genus Trebouxia.
Photosynthetic component:
Cyanolichens Although the photobionts are almost always green algae (Chlorophyta), sometimes the lichen contains Cyanobacteria, taxonomically bacteria, and sometimes both types of photobionts are found in the same lichen.
A cyanolichen is a lichen with a cyanobacterium as its main photosynthetic component (photobiont).
Many cyanolichens are small and black, and have limestone as the substrate.
Another cyanolichen group, the jelly lichens ( e.g., from the genera Collema or Leptogium) are large and foliose (e.g., species of Peltigera, Lobaria, and Degelia. These lichen species are grey-blue, especially when dampened or wet. Many of these characterize the Lobarion communities of higher rainfall areas in western Britain, e.g., in the Celtic Rainforest.
Parasitic fungi:
Some fungi can only be found living on lichens as obligate parasites; They are not considered part of the lichen. These are referred to as “lichenolous fungi”. | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**Side platform**
Side platform:
A side platform (also known as a marginal platform or a single-face platform) is a platform positioned to the side of one or more railway tracks or guideways at a railway station, tram stop, or transitway. A station having dual side platforms, one for each direction of travel, is the basic design used for double-track railway lines (as opposed to, for instance, the island platform where a single platform lies between the tracks). Side platforms may result in a wider overall footprint for the station compared with an island platform where a single width of platform can be shared by riders using either track.In some stations, the two side platforms are connected by a footbridge running above and over the tracks. While a pair of side platforms is often provided on a dual-track line, a single side platform is usually sufficient for a single-track line.
Layout:
Where the station is close to a level crossing (grade crossing) the platforms may either be on the same side of the crossing road or alternatively may be staggered in one of two ways. With the 'near-side platforms' configuration, each platform appears before the intersection and with 'far-side platforms' they are positioned after the intersection.In some situations a single side platform can be served by multiple vehicles simultaneously with a scissors crossing provided to allow access mid-way along its length.Larger stations may have two side platforms with several island platforms in between. Some are in a Spanish solution format, with two side platforms and an island platform in between, serving two tracks.
Layout:
In some situations a single side platform may be in use with the other one (side platform) disused like with Ryde Esplanade. | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**SQLf**
SQLf:
SQLf is a SQL extended with fuzzy set theory application for expressing flexible (fuzzy) queries to traditional (or ″Regular″) Relational Databases. Among the known extensions proposed to SQL, at the present time, this is the most complete, because it allows the use of diverse fuzzy elements in all the constructions of the language SQL.SQLf is the only known proposal of flexible query system allowing linguistic quantification over set of rows in queries, achieved through the extension of SQL nesting and partitioning structures with fuzzy quantifiers. It also allows the use of quantifiers to qualify the quantity of search criteria satisfied by single rows. Several mechanisms are proposed for query evaluation, the most important being the one based on the derivation principle. This consists in deriving classic queries that produce, given a threshold t, a t-cut of the result of the fuzzy query, so that the additional processing cost of using a fuzzy language is diminished.
Basic block:
The fundamental querying structure of SQLf is the multi-relational block. The conception of this structure is based on the three basic operations of the relational algebra: projection, cartesian product and selection, and the application of fuzzy sets’ concepts. The result of a SQLf query is a fuzzy set of rows that is a fuzzy relation instead of a regular relation.
Basic block:
A basic block in SQLf consists of a SELECT clause, a FROM clause and an optional WHERE clause. The semantic of this query structure is: The SELECT clause corresponds to the projection. It specifies the relations’ attributes (or attribute expressions) that will be selected. The resulting table is a fuzzy set and it is given in decreasing ordered of satisfaction degree.
Basic block:
The SELECT clause specifies also a calibration that is intended to restrict the set of rows retrieved. There are two kinds of calibrations: quantitative and qualitative. In quantitative calibration the user specifies the number of results to be retrieved, so that the query will retrieve the rows with highest membership degrees up to the number of required answers. In qualitative calibration the user specifies a minim level of satisfaction that must have any retrieved row.
Basic block:
The FROM clause corresponds to the Cartesian Product. The consult is made on the Cartesian Product of the relations that are specified in this clause.
Basic block:
The WHERE clause corresponds to the selection. It specifies the condition for which the satisfaction degree will be calculated. Rows that do not satisfy at all the condition are rejected. This condition is a fuzzy predicate that may involve any attribute of the relations.The following is an example of a SELECT query that returns a list of hotels that are cheap. The query retrieves all rows from the Hotels table that satisfice the fuzzy predicate cheap defined by the fuzzy set μ=(∞, ∞, 25, 30). The result is sorted in descending order by the membership degree of the query. | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**Behavioral retargeting**
Behavioral retargeting:
Behavioral retargeting (also known as behavioral remarketing, or simply, retargeting) is a form of online targeted advertising by which online advertising is targeted to consumers based on their previous internet behaviour. Retargeting tags online users by including a pixel within the target webpage or email, which sets a cookie in the user's browser.
Once the cookie is set, the advertiser is able to show ads (often display ads) to that user elsewhere on the internet via an ad exchange.
Behavioral retargeting:
Dynamic creative (also known as personalized retargeting), allows an advertiser to display a banner created on-the-fly for a particular consumer based on specific pages that they viewed. For example, if a consumer visits an advertiser's website and browses products A, B, and C – they will then be retargeted with a display banner featuring the exact products A, B, and C that they previously viewed. This is typically restricted to the visitor's browsing on a single website.
Behavioral retargeting:
A refined version improves on re-engagement with customers. If a customer begins an online order, for example, but fails to complete it, a flag indicates they had an interest in the product being ordered. Later, ads showing the product of interest can be custom-linked to point back into the order system. When the user clicks on the ad, they are returned to their incomplete order.
Types:
While all retargeting depends on setting cookies in a user's browser, there are several different methods of doing this: Site retargeting Search retargeting Link retargeting Email retargeting Social retargeting
Pricing:
Retargeting ad campaigns usually run on lower cost media, such as display ads, which not only increases effectiveness by specifically targeting an interested audience, but also improves the overall ROI of the advertiser. A common use-case of retargeting is situations where a website visitor's actions did not result in a sale or conversion.Retargeting providers employ a variety of pricing models to charge advertisers for the ads viewed by consumers. Three prominent models include: CPM (Cost per mille or cost per thousand) CPC (cost per click) CPA (cost per action)Cost per impression (CPM) is a common metric used in the online advertising industry to charge advertisers for inventory based on a set price per thousand-page impressions. An impression is defined as any time a banner ad loads on an individual's web browser.
Pricing:
Pay per click (PPC) charges advertisers for every verifiable click that leads consumers back to a retailer's website. Unlike the CPM model, which charges advertisers a flat rate, advertisers working under the PPC model are only charged when a person clicks on an ad.
Cost per action (CPA) is a pricing model in which advertisers are charged based on pre-arranged action (a purchase, a view through, etc.), although a completed sale is the most common action used under the CPA model.
Concerns:
In the United States, several organizations, including the Federal Trade Commission, Congress and the media, have expressed privacy concerns around the practice of retargeting; however, responsible personalized retargeting providers don't collect personally identifiable information (PII) on consumers. Providers should be blind to a user's age, sex and other personal information. Instead, providers rely upon data gathered from cookies that are placed on a consumer's browser by the websites they visit. This information should not be shared among publishers, other advertisers or third parties and cannot be linked to a specific user. The United States has not legislated many laws around the practice, and instead relies upon the industry and its overarching organizations, such as the Interactive Advertising Bureau, Network Advertising Initiative and TRUSTe to self-regulate. In October 2010, the IAB announced its Advertising Option Icon, which partner sites will place near banner advertisements that collect non-PII user data.In the EU, the 2002 ePrivacy Directive and its 2009 revision require opt-in consent for the use of cookies and stipulate that users must be given the option of opting out. | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**British Society for Developmental Biology**
British Society for Developmental Biology:
The British Society for Developmental Biology (BSDB) is a scientific society promoting developmental biology research; it is open to anyone with an interest in the subject who agrees with the principles of the Society.
History:
The British Society for Developmental Biology was founded in 1948 as the London Embryologists’ Club. In 1964, the club was expanded into a scientific society, named the Society for Developmental Biology. In 1964, the Society for the Study of Growth and Development in the United States had also voted to take on the same name, and they took over sponsorship of the journal Developmental Biology in 1966. Consequently, the smaller British society changed to its current name in 1969.
Awards:
The society administers four annual awards and a studentship. The Waddington Medal was first awarded in 1998. It is named after C. H. Waddington, a leading British embryologist and geneticist, and is awarded to "an outstanding individual who has made major contributions to any aspect of Developmental Biology in the UK".Award winners include: 1998 Cheryll Tickle 1999 Rosa Beddington 2000 Peter Lawrence 2001 Mike Bate 2002 Jonathan Slack 2003 Julian Lewis 2004 Jeff Williams 2005 Michael Akam 2006 Claudio Stern 2007 David Ish-Horowicz 2008 Pat Simpson 2009 Liz Robertson 2010 Robin Lovell-Badge 2011 Christopher Wylie 2012 Alfonso Martinez Arias 2013 Jim Smith 2014 Philip Ingham 2015 Lewis Wolpert 2016 Enrico Coen 2017 William Harris 2018 Richard Lavenham GardnerIn 2016, the society added the Cheryll Tickle Medal, which is awarded to a mid-career female scientist. It is named after the embryologist Cheryll Tickle, the first winner of the Waddington Medal. Winners include: 2016 Abigail Saffron Tucker 2017 Jenny Nichols 2018 Christiana Ruhrberg 2019 Bénédicte SansonThe society also has awards for early career scientists: The Beddington Medal is awarded annually for the "best PhD thesis in developmental biology" defended in the year prior to the award; the Dennis Summerbell Lecture is an award that is delivered annually by a junior researcher at either PhD or postdoctoral level; and summer studentships are available for undergraduate students. | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**Gender taxonomy**
Gender taxonomy:
The gender taxonomy is a classification of the range of different levels at which humans vary in sexual characteristics. It is mainly used by medical specialists working in the area of sex research.John Money and Milton Diamond are probably the best known researchers in this field. Money earned his PhD for research into human hermaphroditism and pseudohermaphroditism, now known as intersex conditions. The taxonomy starts at the simplest, biological level and traces differentiations expressed at the increasingly complicated levels produced over the course of the human life cycle. | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**Simple Features**
Simple Features:
Simple Features (officially Simple Feature Access) is a set of standards that specify a common storage and access model of geographic features made of mostly two-dimensional geometries (point, line, polygon, multi-point, multi-line, etc.) used by geographic information systems.
It is formalized by both the Open Geospatial Consortium (OGC) and the International Organization for Standardization (ISO).
Simple Features:
The ISO 19125 standard comes in two parts. Part 1, ISO 19125-1 (SFA-CA for "common architecture"), defines a model for two-dimensional simple features, with linear interpolation between vertices, defined in a hierarchy of classes; this part also defines representation of geometry in text (WKT) and binary (WKB) forms. Part 2 of the standard, ISO 19125-2 (SFA-SQL), defines a "SQL/MM" language binding API for SQL under the prefix "SF_". The open access OGC standards cover additionally APIs for CORBA and OLE/COM, although these have lagged behind the SQL one and are not standardized by ISO. There are also adaptations to other languages covered below.
Simple Features:
The ISO/IEC 13249-3 SQL/MM Spatial extends the Simple Features data model mainly with circular interpolations (e.g. circular arcs) and adds other features like coordinate transformations and methods for validating geometries as well as Geography Markup Language support.
Details:
Part 1 The geometries are associated with spatial reference systems. The standard also specifies attributes, methods and assertions with the geometries, in the object-oriented style. In general, a 2D geometry is simple if it contains no self-intersection. The specification defines DE-9IM spatial predicates and several spatial operators that can be used to generate new geometries from existing geometries.
Part 2 Part 2 is a SQL binding to Part 1, providing a translation of the interface to non-object-oriented environments. For example, instead of a someGeometryObject.isEmpty() as in Part 1, SQL/MM uses a ST_IsEmpty(...) function in SQL.
Spatial The spatial extension adds the datatypes "Circularstring", "CompoundCurve", "CurvePolygon", "PolyhedralSurface", the last of which is also included into the OGC standard. It also defines the SQL/MM versions of these types and operations on them.
Implementations:
Direct implementations of Part 2 (SQL/MM) include: MySQL Spatial Extensions. Up to MySQL 5.5, all of the functions that calculate relations between geometries are implemented using bounding boxes not the actual geometries. Starting from version 5.6, MySQL offers support for precise object shapes.
MonetDB/GIS extension for MonetDB.
PostGIS extension for PostgreSQL, also supporting some of the SQL/MM Spatial features.
SpatiaLite extension for SQLite Oracle Spatial, which also implements some of the advanced features from SQL/MM Spatial.
IBM Db2 Spatial Extender and IBM Informix Spatial DataBlade.
Microsoft SQL Server since version 2008, with significant additions in the 2012 version.
SAP Sybase IQ.
SAP HANA as of 1.0 SPS6.Adaptations include: Implementations of the CORBA and OLE/COM interfaces detailed above are mainly produced by commercial vendors maintaining legacy technology.
R: The sf package implements Simple Features and contains functions that bind to GDAL for reading and writing data, to GEOS for geometrical operations, and to PROJ for projection conversions and datum transformations.
The GDAL library implements the Simple Features data model in its OGR component.
The Java-based deegree framework implements SFA (part 1) and various other OGC standards.
Implementations:
The Rust library geo_types implements geometry primitives that adhere to the simple feature access standards.GeoSPARQL is an OGC standard that is intended to allow geospatially-linked data representation and querying based on RDF and SPARQL by defining an ontology for geospatial reasoning supporting a small Simple Features (as well as DE-9IM and RCC8) RDFS/OWL vocabulary for GML and WKT literals.As of 2012, various NoSQL databases had very limited support for "anything more complex than a bounding box or proximity search". | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**Multisided record**
Multisided record:
A multisided record is a type of vinyl record that has more than one groove per side. This technique allows hidden tracks to be encoded on LPs, 45 rpms and 78 rpms. On a disc that has a multi-groove, whether the listener plays the main track or the hidden track depends on where the stylus is cued.
The most frequently cited example of a multiple-groove record is Monty Python's infamous "three-sided" Matching Tie and Handkerchief album, issued in 1973. One side of the album (both sides were labeled "Side 2") was "normal"; the other contained a pair of grooves, each of which held different material (later pressings of the record did not include the double groove).
Multisided record:
Another memorable example of a multiple-groove recording was the 1980 flexi disc entitled It's a Super-Spectacular Day issued by MAD magazine. The disc played a standard introductory section about the start of a wonderful, "super-spectacular" day, then produced one of several different comedic "bad" endings to that day, involving such topics as alien abduction, zits, street violence, and the horrors of a visiting mother-in-law.
Multisided record:
Other uses to which multiple-groove recordings have been put include various games (such as horse races or mystery games) where the outcome is determined by which of the record's multiple grooves is played.
Examples:
Some records to have incorporated this feature, include:- So-called Puzzle Plates produced by the Gramophone Company in London in 1898 and 1899: these were discs with two interleaved tracks, issued as E5504, 9290, 9296. Their most famous was a three-track Puzzle Plate (9317) recorded in January 1901 and given as the prize for a competition, for which several master recordings had to be made, distinguished by suffix letters against the catalogue number.
Examples:
One of the earliest examples of a three-track side was a 1901 Pre-Dog Victor A-821 Fortune Telling Record. This is a multi-Track disc with three recording tracks that go all the way through the record. It is titled "Fortune Telling Puzzle Record a song and two Fortunes, See if you can find them." "The Fortune Teller Song," a 1951 single by the Fontane Sisters (RCA Victor 4106), contained four different versions of the song, each with a different ending.
Examples:
"Laura Scudder's Magic Record," a 1969 record produced by George Garabedian's Mark 56 Records and offered as a promotional give-away by Laura Scudder's Potato Chips. Each side contained three different songs that would play at random depending upon the drop of the stylus. https://www.discogs.com/Various-Laura-Scudders-Magic-Record/release/10469094 "The Monty Python Matching Tie and Handkerchief" (1973), on its original pressing one of the LP's "side two"'s had twin grooves, thus making a three-sided LP.
Examples:
Some editions of The Goodies' "The Funky Gibbon" single (1975) have a double grooved title track with alternative codas.
A special 12" version of M's single "Pop Muzik" (1979) features "Pop Muzik" and "M Factor" on one side. The single was credited on its cover as "The first 'Double Groove' single", although this claim is questionable.
John Cooper Clarke's 7" Splat/Twat S EPC 7982 (1979) has Twat (live recording) and Splat (censored version) on two grooves on the A side.
Henny Youngman's 128 Greatest Jokes, a 1980 Rhino Records LP, featured four-track mastering that allowed for a different random selection of Youngman's jokes to be heard each time the album was played. Rhino promoted the gimmick as "Trick-Track" recording.
The LP You're the Guy I Want to Share My Money With (1981), featuring a "three-track" side: each track contained a different recording of the title song, alternately performed by Laurie Anderson, William S. Burroughs, or John Giorno.
The 12" single "Catalogue Clothes" (1986) by World Domination Enterprises has a double groove on the B-side. The two tracks are different mixes of "Dans Une Ville.
Basia's 1987 10" Promises/Give me That has two grooves, Groove A is Promises (French Mix) and Groove 2 is Give me That. What makes it more special is it is on white vinyl.
The 10" single of Alexander O'Neal's "Criticize" (1987), features two versions of the title song on side A.
A special 12" version of The Sugarcubes' single "Birthday" (1988) features one groove containing "Christmas Eve" and the other containing "Christmas Day"; both are different recordings of "Birthday" featuring The Jesus and Mary Chain.
The 12" single of Me Myself and I (1989) by De La Soul The 12" single of Kate Bush's "The Sensual World" (1989), with one track containing the standard vocal version and the other playing an instrumental version.
The 10" single of the Fine Young Cannibals' "Good Thing" (1989), which held two different mixes of the same song.
The 12" version of Tool's "Opiate" EP (1992) features one track that will play either "The Gaping Lotus Experience" or "Cold and Ugly (Live)" depending on where the stylus is placed.
The double-LP release of Marillion's 1994 concept album Brave featured a double groove on the second side of the second record. The first groove played the regular track listing ("The Great Escape" and "Made Again"), while the second played only an alternate version of "The Great Escape" with different lyrics, presenting an alternate ending to the album's narrative.
The Record Store Day 2011 exclusive 10-inch single of “Things Change” by Dom features a double-grooved A side that plays a different song depending on where the stylus is placed. Both tracks are listed on the label.
The LP version of Disco Volante (1995) by the avant-garde metal band Mr. Bungle contained a hidden groove during "Sleep Part II: Carry Stress In The Jaw" with an untitled hidden song.
The 7" version of Garbage's 1995 single "Only Happy When It Rains" features a double groove on the side B. Depending on where the stylus is placed, it plays either "Girl Don't Come" or "Sleep".
Scntfc's 2012 7" vinyl album "Sword & Sworcery: Moon Grotto 7" had a double groove containing a secret audio message.
The 12" version of the album Behind the Sun (2014) by Motorpsycho contains two instrumental tracks that are cut in parallel such that the stylus will randomly play one of the two songs.
Jack White's album Lazaretto (2014) has a double groove featuring two unique intros to the same song, one acoustic and one electric. | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**Speed ring**
Speed ring:
A speed ring is a solid metal ring-shaped disk which is used to attach a soft box to a studio (strobe) or continuous (hotlight) light source.
Speed ring:
There are 4 to 8 holes drilled into the circumference of the ring which receives the metal rods of the soft box; they are held in place by tension. Shapes can vary depending on the manufacturer. Typically, the opening in the center ranges from 4 to 7 inches, allowing the light source to enter the softbox or other modifier. Common ring types are Bowens, Profoto, and Alien Bees. | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**Arion (software)**
Arion (software):
Arion is a physically based, unbiased render engine developed by RandomControl.
Versions:
Arion standalone is a general purpose rendering tool with a visual UI. There are also versions that integrate into 3ds Max and Rhinoceros. | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**Intel Cluster Ready**
Intel Cluster Ready:
The Intel Cluster Ready certification is a marketing program from Intel. It is aimed at hardware and software vendors in the low-end and mid-range cluster market. To get certified, systems have to fulfill a minimum set of cluster-specific requirements. This way, vendors of parallel software can build their applications on a basic cluster platform, trusting certain components to be present. Other drivers, libraries and tools will have to be provided by the software vendor or its partners, or by a system integrator.
Description:
The program was announced in June 2007.
The nodes of an Intel Cluster Ready compliant cluster are based on Xeon server processors and PC hardware, interconnected through Ethernet or InfiniBand. The operating system is a Linux distribution conforming to a specific file system layout. Also included are Intel's closed source but publicly available parallel libraries: the Message Passing Interface, Threading Building Blocks, and Math Kernel Library.
Intel only specifies the requirements a cluster has to fulfill to get certified. The specific implementation is the responsibility of the platform vendor. Intel's Cluster Checker checks the system's compliance. It is not only deployed by the vendor, the integrator and the end user to verify the system, it can also be used to troubleshoot an operational cluster.
While cluster hardware gets certified, software can be registered as well. Intel provides a minimal cluster infrastructure where software vendors can run their package, test scripts and test data. After successful completion, the application gets registered as being Intel Cluster Ready compliant. The Cluster Ready program is free for both hardware and software vendors.
Description:
The Intel Cluster Ready program does not primarily include the high-end clusters used for scientific calculations at universities and research institutes. It aims to commoditize the parallel systems used for industrial and commercial applications. According to IDC, more than half of the servers currently sold for technical applications is deployed as part of a cluster. For example, these systems are used for industrial computations, financial analyses, and modelling in engineering. IDC expects clustered systems to responsible for more than three-quarters of the high-performance technical computing market.
AMD-based clusters:
Although the Cluster Ready program is aimed at systems built on Intel's Xeon processors, the Cluster Checker can also be used to verify an Advanced Micro Devices-based system. Intel's parallel libraries run on AMD hardware with the same performance and are fully supported by Intel. According to Werner Krotz-Vogel, Technical Marketing Engineer at Intel's Cluster Ready team, the Math Kernel Library (MKL) runs even faster than the open source library Automatically Tuned Linear Algebra Software (ATLAS) on an AMD Opteron system. | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**Isoflavone 7-O-methyltransferase**
Isoflavone 7-O-methyltransferase:
In enzymology, an isoflavone 7-O-methyltransferase (EC 2.1.1.150) is an enzyme that catalyzes the chemical reaction S-adenosyl-L-methionine + a 7-hydroxyisoflavone ⇌ S-adenosyl-L-homocysteine + a 7-methoxyisoflavoneThus, the two substrates of this enzyme are S-adenosyl methionine and 7-hydroxyisoflavone, whereas its two products are S-adenosylhomocysteine and 7-methoxyisoflavone.
This enzyme belongs to the family of transferases, specifically those transferring one-carbon group methyltransferases. The systematic name of this enzyme class is S-adenosyl-L-methionine:hydroxyisoflavone 7-O-methyltransferase. This enzyme participates in isoflavonoid biosynthesis. | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**Dihydrolipoamide dehydrogenase**
Dihydrolipoamide dehydrogenase:
Dihydrolipoamide dehydrogenase (DLD), also known as dihydrolipoyl dehydrogenase, mitochondrial, is an enzyme that in humans is encoded by the DLD gene. DLD is a flavoprotein enzyme that oxidizes dihydrolipoamide to lipoamide.
Dihydrolipoamide dehydrogenase:
Dihydrolipoamide dehydrogenase (DLD) is a mitochondrial enzyme that plays a vital role in energy metabolism in eukaryotes. This enzyme is required for the complete reaction of at least five different multi-enzyme complexes. Additionally, DLD is a flavoenzyme oxidoreductase that contains a reactive disulfide bridge and a FAD cofactor that are directly involved in catalysis. The enzyme associates into tightly bound homodimers required for its enzymatic activity.
Structure:
The protein encoded by the DLD gene comes together with another protein to form a dimer in the central metabolic pathway. Several amino acids within the catalytic pocket have been identified as important to DLD function, including R281 and N473. Although the overall fold of the human enzyme is similar to that of yeast, the human structure is different in that it has two loops that extend from the general protein structure and into the FAD binding sites when bound the NAD+ molecule, required for catalysis, is not close to the FAD moiety. However, when NADH is bound instead, it is stacked directly op top of the FAD central structure. The current hE3 structures show directly that the disease-causing mutations occur at three locations in the human enzyme: the dimer interface, the active site, and the FAD and NAD(+)-binding sites.
Function:
The DLD homodimer functions as the E3 component of the pyruvate, α-ketoglutarate, α-adipate and branched-chain amino acid-dehydrogenase complexes and the glycine cleavage system, all in the mitochondrial matrix. In these complexes, DLD converts dihydrolipoic acid and NAD+ into lipoic acid and NADH.
DLD also has diaphorase activity, being able to catalyze the oxidation of NADH to NAD+ by using different electron acceptors such as O2, labile ferric iron, nitric oxide, and ubiquinone. DLD is thought to have a pro-oxidant role by reducing oxygen to a superoxide or ferric to ferrous iron, which then catalyzes production of hydroxyl radicals.
Diaphorase activity of DLD may have an antioxidant role through its ability to scavenge nitric oxide and to reduce ubiquinone to ubiquinol. The dihyrolipamide dehydrogenase gene is known to have multiple splice variants.
Moonlighting function:
Certain DLD mutations can simultaneously induce the loss of a primary metabolic activity and the gain of a moonlighting proteolytic activity. The moonlighting proteolytic activity of DLD is revealed by conditions that destabilize the DLD homodimer and decrease its DLD activity. Acidification of the mitochondrial matrix, as a result of ischemia-reperfusion injury, can disrupt the quaternary structure of DLD leading to decreased dehydrogenase activity and increased diaphorase activity.
Moonlighting function:
The moonlighting proteolytic activity of DLD could also arise under pathological conditions. Proteolytic activity can further complicate the reduction in energy metabolism and an increase in oxidative damage as a result of decreased DLD activity and an increase in diaphorase activity respectively. With its proteolytic function, DLD removes a functionally vital domain from the N-terminus of frataxin, a mitochondrial protein involved in iron metabolism and antioxidant protection.
Clinical significance:
In humans, mutations in DLD are linked to a severe disorder of infancy with failure to thrive, hypotonia, and metabolic acidosis.
DLD deficiency manifests itself in a great degree of variability, which has been attributed to varying effects of different DLD mutations on the stability of the protein and its ability to dimerize or interact with other components of the three α-ketoacid dehydrogenase complexes.
With its proteolytic function, DLD causes a deficiency in frataxin, which leads to the neurodegenerative and cardiac disease, Friedreich's ataxia.
Enzyme regulation:
This protein may use the morpheein model of allosteric regulation. | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**Tent map**
Tent map:
In mathematics, the tent map with parameter μ is the real-valued function fμ defined by := min {x,1−x}, the name being due to the tent-like shape of the graph of fμ. For the values of the parameter μ within 0 and 2, fμ maps the unit interval [0, 1] into itself, thus defining a discrete-time dynamical system on it (equivalently, a recurrence relation). In particular, iterating a point x0 in [0, 1] gives rise to a sequence xn :xn+1=fμ(xn)={μxnforxn<12μ(1−xn)for12≤xn where μ is a positive real constant. Choosing for instance the parameter μ = 2, the effect of the function fμ may be viewed as the result of the operation of folding the unit interval in two, then stretching the resulting interval [0, 1/2] to get again the interval [0, 1]. Iterating the procedure, any point x0 of the interval assumes new subsequent positions as described above, generating a sequence xn in [0, 1].
Tent map:
The μ=2 case of the tent map is a non-linear transformation of both the bit shift map and the r = 4 case of the logistic map.
Behaviour:
The tent map with parameter μ = 2 and the logistic map with parameter r = 4 are topologically conjugate, and thus the behaviours of the two maps are in this sense identical under iteration.
Depending on the value of μ, the tent map demonstrates a range of dynamical behaviour ranging from predictable to chaotic.
If μ is less than 1 the point x = 0 is an attractive fixed point of the system for all initial values of x i.e. the system will converge towards x = 0 from any initial value of x.
If μ is 1 all values of x less than or equal to 1/2 are fixed points of the system.
Behaviour:
If μ is greater than 1 the system has two fixed points, one at 0, and the other at μ/(μ + 1). Both fixed points are unstable, i.e. a value of x close to either fixed point will move away from it, rather than towards it. For example, when μ is 1.5 there is a fixed point at x = 0.6 (since 1.5(1 − 0.6) = 0.6) but starting at x = 0.61 we get 0.61 0.585 0.6225 0.56625 0.650625 … If μ is between 1 and the square root of 2 the system maps a set of intervals between μ − μ2/2 and μ/2 to themselves. This set of intervals is the Julia set of the map – that is, it is the smallest invariant subset of the real line under this map. If μ is greater than the square root of 2, these intervals merge, and the Julia set is the whole interval from μ − μ2/2 to μ/2 (see bifurcation diagram).
Behaviour:
If μ is between 1 and 2 the interval [μ − μ2/2, μ/2] contains both periodic and non-periodic points, although all of the orbits are unstable (i.e. nearby points move away from the orbits rather than towards them). Orbits with longer lengths appear as μ increases. For example: appears at μ=1 appears at μ=1+52 appears at 1.8393 If μ equals 2 the system maps the interval [0, 1] onto itself. There are now periodic points with every orbit length within this interval, as well as non-periodic points. The periodic points are dense in [0, 1], so the map has become chaotic. In fact, the dynamics will be non-periodic if and only if x0 is irrational. This can be seen by noting what the map does when xn is expressed in binary notation: It shifts the binary point one place to the right; then, if what appears to the left of the binary point is a "one" it changes all ones to zeroes and vice versa (with the exception of the final bit "one" in the case of a finite binary expansion); starting from an irrational number, this process goes on forever without repeating itself. The invariant measure for x is the uniform density over the unit interval. The autocorrelation function for a sufficiently long sequence { xn } will show zero autocorrelation at all non-zero lags. Thus xn cannot be distinguished from white noise using the autocorrelation function. Note that the r = 4 case of the logistic map and the μ=2 case of the tent map are homeomorphic to each other: Denoting the logistically evolving variable as yn , the homeomorphism is sin −1(yn1/2).
Behaviour:
If μ is greater than 2 the map's Julia set becomes disconnected, and breaks up into a Cantor set within the interval [0, 1]. The Julia set still contains an infinite number of both non-periodic and periodic points (including orbits for any orbit length) but almost every point within [0, 1] will now eventually diverge towards infinity. The canonical Cantor set (obtained by successively deleting middle thirds from subsets of the unit line) is the Julia set of the tent map for μ = 3.
Magnifying the orbit diagram:
A closer look at the orbit diagram shows that there are 4 separated regions at μ ≈ 1. For further magnification, 2 reference lines (red) are drawn from the tip to suitable x at certain μ (e.g., 1.10) as shown.With distance measured from the corresponding reference lines, further detail appears in the upper and lower part of the map. (total 8 separated regions at some μ)
Asymmetric tent map:
The asymmetric tent map is essentially a distorted, but still piecewise linear, version of the μ=2 case of the tent map. It is defined by vn+1={vn/aforvn∈[0,a](1−vn)/(1−a)forvn∈[a,1] for parameter a∈[0,1] . The μ=2 case of the tent map is the present case of a=12 . A sequence { vn } will have the same autocorrelation function as will data from the first-order autoregressive process wn+1=(2a−1)wn+un+1 with { un } independently and identically distributed. Thus data from an asymmetric tent map cannot be distinguished, using the autocorrelation function, from data generated by a first-order autoregressive process. | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**Ecological speciation**
Ecological speciation:
Ecological speciation is a form of speciation arising from reproductive isolation that occurs due to an ecological factor that reduces or eliminates gene flow between two populations of a species. Ecological factors can include changes in the environmental conditions in which a species experiences, such as behavioral changes involving predation, predator avoidance, pollinator attraction, and foraging; as well as changes in mate choice due to sexual selection or communication systems. Ecologically-driven reproductive isolation under divergent natural selection leads to the formation of new species. This has been documented in many cases in nature and has been a major focus of research on speciation for the past few decades.: 179 Ecological speciation has been defined in various ways to identify it as distinct from nonecological forms of speciation. The evolutionary biologist Dolph Schluter defines it as "the evolution of reproductive isolation between populations or subsets of a single population by adaptation to different environments or ecological niches", while others believe natural selection is the driving force. The key difference between ecological speciation and other kinds of speciation is that it is triggered by divergent natural selection among different habitats, as opposed to other kinds of speciation processes like random genetic drift, the fixation of incompatible mutations in populations experiencing similar selective pressures, or various forms of sexual selection not involving selection on ecologically relevant traits. Ecological speciation can occur either in allopatry, sympatry, or parapatry—the only requirement being that speciation occurs as a result of adaptation to different ecological or micro-ecological conditions.Ecological speciation can occur pre-zygotically (barriers to reproduction that occur before the formation of a zygote) or post-zygotically (barriers to reproduction that occur after the formation of a zygote). Examples of pre-zygotic isolation include habitat isolation, isolation via pollinator-pollination systems, and temporal isolation. Examples of post-zygotic isolation involve genetic incompatibilities of hybrids, low fitness hybrids, and sexual selection against hybrids.
Ecological speciation:
Some debate exists over the framework concerning the delineation of whether a speciation event is ecological or nonecological. "The pervasive effect of selection suggests that adaptive evolution and speciation are inseparable, casting doubt on whether speciation is ever nonecological". However, there are numerous examples of closely related, ecologically similar species (e.g., Albinaria land snails on islands in the Mediterranean, Batrachoseps salamanders from California, and certain crickets and damselflies), which is a pattern consistent with the possibility of nonecological speciation.
Ecological causes of divergent selection:
Divergent selection is key to the occurrence of ecological speciation. Three ecological causes of divergent selection have been identified: differences in environmental conditions, ecological interactions, and sexual selection. The causes are following list Differences in environmental conditions as a prerequisite to speciation is incontrovertibly the most studied. Predation, resource availability (food abundance), climatic conditions, and the structure of a habitat are some of the examples that can differ and give rise to divergent selection. Despite being one of the most studied factors in ecological speciation, many aspects are still less understood such as how prevalent the process is in nature as well as the origin of barriers for post-zygotic isolation (as opposed to the much easier detectable pre-zygotic barriers).: 181 Laboratory experiments involving single-environmental differences are limited and have often not tracked the traits involved in isolation. Studies in nature have focused on a variety of environmental factors such as predation-caused divergent selection; however, little has been studied in regards to pathogens or parasites.
Ecological causes of divergent selection:
Ecological interactions can drive divergent selection between populations in sympatry. Examples of these interactions can be intraspecific (between the same species) and interspecific (between different species) competition or relationships such as those of ecological facilitation. Interspecific competition in particular has support from experiments; however it is unknown if it can give rise to reproductive isolation despite driving divergent selection. Reinforcement (the strengthening of isolation by selection favoring the mating of members of their own populations due to reduced fitness of hybrids) is considered to be a form of, or involved in, ecological speciation. Though, debate exists as to how to determine ultimate causes since reinforcement can complete the speciation process regardless of how it originated. Further, character displacement can have the same effect.
Ecological causes of divergent selection:
Sexual selection can play a role in ecological speciation as the recognition of mates is central to reproductive isolation—that is, if a species cannot recognize its potential mates, the flow of genes is suspended. Despite its role, only two types of sexual selection can be implicated in ecological speciation: the spatial variation in secondary sexual traits (sexual traits that arise specifically at sexual maturity) or communication and mating systems. This restriction is based on the fact that they produce diverging environments in which selection can act. For example, isolation will increase between two populations where there is a mismatch between signals (such as the feather display of a male bird) and the preferences (such as the sexual preferences of a female bird). This pattern has been detected in stickleback fish.
Types of reproductive isolation:
Habitat isolation Populations of a species can become spatially isolated due to preferences for separate habitats. The separation decreases the chance of mating to occur between the two populations, inhibiting gene flow, and promoting pre-zygotic isolation to lead to complete speciation. Habitat isolation is not equivalent to a geographic barrier like that of allopatric speciation.: 182 Instead, it is based on genetic differences, where one species is unable to exploit a different environment, resulting from fitness advantages, fitness disadvantages, or resource competition.: 182 Jerry Coyne and H. Allen Orr posit two different forms of habitat isolation: microspatial habitat isolation (where matings between two species are reduced by preferences or adaptations to ecologically differing areas, despite occupying the same generalized area) and macrospatial habitat isolation (defined by fully allopatric habitats that inhibit gene flow.): 182–3 Identification of both forms of habitat isolation in nature is difficult due to the effects of geography. Measuring microspatial isolation demands several factors:: 184 the spatial separation of different species' members is greater than those of members of the same species during simultaneous breeding periods, the spatial separation reduces gene flow decreased gene flow is directly the result of decreased mating genetic differences correspond to the spatial separationAllopatric distributions pose several problems for detecting true habitat isolation in that different habitats of two allopatrically isolated species does not imply ecologically caused speciation. Alternative explanations could account for the patterns:: 185 species differences may be caused by geographic isolation the species may or may not occupy different habitats if they existed in sympatry in cases of similar habitats in allopatry, species may be adapted to unknown ecological factors if the species existed in sympatry, competition may drive habitat segregation that would be undetectable in allopatryThese issues (with both micro- and macro-spatial isolation) can be overcome by field or laboratory experiments such as transplantation of individuals into opposite habitats: 185 (though this can prove difficult if individuals are not completely unfit for the imposed habitat).: 186 Habitat isolation can be measured for a species pair ( a and b ) during a breeding period by: 1−pab2papb Here, pab is the proportion of encounters between matings that involve partners of a different species that are observed. pa is the proportion of total individuals of species a . pb is the proportion of total individuals of species b . The expected proportion of mating encounters between different species if mating is random is denoted by 2papb . A statistic of 1 indicates no mating encounters of different species where 0 indicates random mating of different species.
Types of reproductive isolation:
Geography Ecological speciation caused by habitat isolation can occur in any geographic sense, that is, either allopatrically, parapatrically, or sympatrically. Speciation arising by habitat isolation in allopatry (and parapatry) is straightforward in that reduced gene flow between two populations acquire adaptations that fit the ecological conditions of their habitat. The adaptations are reinforced by selection and, in many cases such as with animals, are reinforced by behavioral preferences (e.g. in birds that prefer specific vocalizations).: 189 A classic example of habitat isolation occurring in allopatry is that of host-specific cospeciation: 189 such as in the pocket gophers and their host chewing lice or in the fig wasp-fig tree relationship and the yucca-yucca moth relationship—examples of ecological speciation caused by pollinator isolation.: 189 In sympatry, the scenario is more complex, as gene flow may not be reduced enough to permit speciation. It is thought that selection for niche divergence can drive the process. In addition, if sympatry results from the secondary contact of two previously separated populations, the process of reinforcement, the selection against unfit hybrids between the two populations, may drive their complete speciation. Competition for resources may also play a role.: 191 Habitat isolation is a significant impediment to gene flow and is exhibited by the common observation that plants and animals are often spatially separated in relation to their adaptations.: 183 Numerous field studies, transplantation and removal experiments, and laboratory studies have been conducted to understand the nature of speciation caused by habitat isolation.: 186–188 Horkelia fusca, for example, grows on California slopes and meadows above 4500 feet, where its closet relatives H. californica and H. cuneata grow below 3200 feet in coastal habitats. When species are transplanted to alternate habitats, their viability is reduced, indicating that gene flow between the populations is unlikely. Similar patterns have been found with Artemisia tridentata tridentata and A. tridentata subsp. vaseyana in Utah, where hybrid zones exists between altitudinal populations, and transplant experiments reduce the fitness of the subspecies.Speciation by habitat isolation has also been studied in serpentine leaf miner flies, ladybird beetles (Epilachna), goldenrod gall flies, Rhagoletis pomonella, leaf beetles, and pea aphids.
Types of reproductive isolation:
Sexual isolation Ecological speciation due to sexual isolation results from differing environmental conditions that modify communication systems or mate choice patterns over time. Examples abound in nature. The coastal snail species Littorina saxatilis has been a focus of research as two ecotypes residing at different shore levels exhibit reproductive isolation as a result of mate choice regarding the body size differences of the ecotype. Both marine and freshwater stickleback fish have shown strong evidence of having speciated this way. Evidence is also found in Neochlamisus bebbianae leaf beetles, Timema cristinae walking-stick insects, and in the butterfly species Heliconius melpomene and H. cydno which are thought to have diverged recently due to assortive mating being enhanced where the species populations meet in sympatry.
Types of reproductive isolation:
Pollinator isolation Angiosperms (flowering plants) require some form of pollination—many of which require another animal to transfer pollen from one flower to another. Biotic pollination methods require pollinators such as insects (e.g. bees, butterflies, moths, wasps, beetles, and other invertebrates), birds, bats, and other vertebrate species. Because of this evolutionary relationship between pollinators and pollen-producing plants, plants and animals become mutually dependent on each other—the pollinator receives food in the form of nectar and the flower gains the ability to propagate its genes.
Types of reproductive isolation:
In the event that an animal uses a different pollination source, plants can become reproductively isolated.: 193 Pollinator isolation is a specific form of sexual isolation. The botanist Verne Grant distinguished between two types of pollinator isolation: mechanical isolation and ethological isolation.: 193 : 75 Mechanical pollinator isolation Mechanical isolation results from anatomical differences of a flower or pollinator preventing pollination from occurring. For example, in the bee Eulaema cingulata, pollen from Catasetum discolor and C. saccatum is attached to different parts of the body (ventrally and dorsally respectively).: 194 Another example is with elephant's head and little elephant's head plants. They are not known to hybridize despite growing in the same region and being pollinated by the same bee species. Pollen is attached to different parts of the bee rendering the flowers isolated. Mechanical isolation also includes pollinators who are unable to pollinate due to physical inabilities.: 194 Nectar spur length, for example, could vary in size in a flower species resulting in pollination from different lepidopteran species due to the lengths preventing body contact with the flower's pollen.
Types of reproductive isolation:
Ethological pollinator isolation Ethological isolation is based on behavioral traits of pollinators that prefer different morphological characteristics of a flower either genetically or through learned behavior. These characteristics could be the overall shape and structure, color, type of nectar, or smell of the flower.: 194 In some cases, mutualisms evolve between a pollinator and its host, cospeciating with near-congruent, parallel phylogenies.: 196 That is, the dependent relationship results in closely identical evolutionary trees indicating that speciation events and the rate of speciation is identical. Examples are found in fig wasps and their fig hosts, with each fig wasp species pollinating a specific fig species. The yucca and yucca moth exhibit this same pattern.
Types of reproductive isolation:
In a striking case, two closely related flowering plants (Erythranthe lewisii and E. cardinalis) have speciated due to pollinator isolation in complete sympatry (speciation occurring without any physical, geographic isolation). E. lewisii has changed significantly from its sister species in that its evolved pink flowers, broad petals, shorter stamens (the pollen-producing part of the plant), and a lower volume of nectar. It is entirely pollinated by bees with almost no crossing in nature. E. cardinalis is pollinated by hummingbirds and exhibits red, tube-shaped flowers, larger stamens, and a lot of nectar. It is thought that nectar volume as well as a genetic component (an allele substitution that controls color variation) maintains isolation. A similar pattern has been found in Aquilegia pubescens and A. formosa. In this species pair, A. pubescens is pollinated by hawkmoths while A. formosa is pollinated by hummingbirds.: 197 Unlike in Erythranthe, these species reside in different habitats but exhibit hybrid forms where their habitats overlap; though they remain separate species suggesting that the hybrid flowers may be less attractive to their pollinator hosts.: 197 Geography Four geographic-based scenarios involving pollinator isolation are known to occur: The most common framework for pollinator isolation in a geographic context implies that floral trait divergence occurs as a result of geographic isolation (allopatrically). From there, a population has the potential to encounter different pollinators ultimately resulting in selection favoring traits to attract the pollinators and achieve reproductive success.: 198 Another scenario involves an initial allopatric stage, wherein secondary contact occurs at a variable level of reproductive isolation—high isolation is effectively allopatric speciation whereas low isolation is effectively sympatric. This "two-stage" model is indicated in the three-spined sticklebacks as well as the apple maggot fly and its apple hosts.
Types of reproductive isolation:
A pollinator can change preferences due to its own evolution driving selection to favor traits that align with the pollinators changed preferences.: 198 There exists the possibility that when two populations become isolated geographically, a plant or pollinator could go extinct in one of the populations driving selection to favor different traits.Jerry Coyne and H. Allen Orr contend that any scenario of pollinator isolation in allopatry demands that incipient stages should be found in different populations. This has been observed to varying degrees in several species-pollinator pairs. Flower size of Raphanus sativus (in this case, wild radish in 32 California populations) has been found to differ in accordance with larger honeybee pollinators. Polemonium viscosum flowers have been found to increase in size along an alpine gradient in the Colorado Rocky Mountains as flies pollinate at the timberline whereas bumblebees pollinate at higher elevations. A similar pattern involving the timing in which hawkmoths (Hyles lineata) are active is documented in three subspecies of Aquilegia coerulea, the Rocky Mountain columbine found across the western United States.The most notable example according to Coyne and Orr is that of the African orchid subspecies Satyrium hallackii hallackii and Satyrium hallackii ocellatum.: 199–200 The latter is pollinated by moths and exhibits long nectar spurs that correlate with the moth's proboscis. Unlike the inland, grassland habitat of subspecies hallackii, ocellatum resides in coastal populations and has short spurs that correlate with its primary carpenter bee pollinator. The moths are unable to find suitable nest sites in coastal habitats while the bees are unable inland. This pattern separates the pollinator populations but does not separate the orchid population driving selection to favor flower differences that better-match the local pollinators. A similar pattern has been detected in studies of the Disa draconis complex in South Africa.
Types of reproductive isolation:
Temporal isolation (allochronic speciation) Temporal isolation is based on the reduction of gene flow between two populations due to different breeding times (phenology). It is also referred to as allochronic isolation, allochronic speciation, or allochrony. In plants, breeding in regards to time could involve the receptivity of stigma to accepting sperm, periods of pollen release (such as in conifer trees where cones disperse pollen via wind), or overall timing of flowering. In contrast, animals often have mating periods or seasons (and many aquatic animals have spawning times).: 202 Migratory patterns have also been implicated in allochronic speciation.: 92–96 For allochronic speciation to be considered to have actually occurred, the model necessitates three major requirements: Phylogenetic analysis indicates the incipient species are sister taxa Breeding timing is genetically-based (heritable to offspring) The source of divergence is explicitly allochrony and not the result of reinforcement or other mechanismsAllochrony is thought to evolve more easily the greater the heritability of reproductive timing—that is, the greater the link between genes and the timing of reproduction—the more likely speciation will occur. Temporal isolation is unique in that it can be explicitly sympatric as well as nongenetic;: 203 however genetic factors must be involved for isolation to lead to complete reproductive isolation and subsequent speciation. Speciation by allochrony is known to occur in three time frames: yearly (e.g. periodic cicadas emerging over decades or multi-decadal bamboo flowerings), seasonal (organisms that breed during times of the year such as winter or summer), and daily (e.g. daily spawning times of corals). The table list below summarizes a number of studies considered to be strong or compelling examples of allochronic speciation occurring in nature.
Types of reproductive isolation:
Other pre-zygotic forms of ecological isolation Selection against migrants, or immigrant inviability, is hypothesized to be a form of ecological isolation. This type of speciation involves the low survival rates of migrants between populations because of their lack of adaptations to non-native habitats. There is little understanding the relationship between post-mating, pre-zygotic isolation and ecology. Post-mating isolation occurs between the process of copulation (or pollination) and fertilization—also known as gametic isolation.: 232 Some studies involving gametic isolation in Drosophila fruit flies, ground crickets, and Helianthus plants suggest that there may be a role in ecology; however it is undetermined.
Types of reproductive isolation:
Post-zygotic forms of ecological isolation Ecologically-independent post-zygotic isolation arises out of genetic incompatibilities between two hybrid individuals of a species. It is thought that in some cases, hybrids have lower fitness especially based on the environment in which they reside. For example, in extreme environments with limited ecological niches to exploit, high fitness is necessitated, whereas if an environment has lots of niches, lower fit individuals may be able to survive for longer. Some studies indicate that these incompatibilities are a cause of ecological speciation because they can evolve quickly through divergent selection.Ecologically-dependent post-zygotic isolation results from the reduce hybrid of fitness due to its position in an ecological niche—that is, parental species occupy slightly different niches, but their hybrid offspring end up requiring a niche that is a blend between the two of which does not typically exist (in regard to a fitness landscape). This has been detected in populations of sticklebacks (Gasterosteus aculeatus), water-lily beetles (Galerucella nymphaeae), pea aphids, and tephritid flies (Eurosta solidaginis).Selection against hybrids can sometimes (it is possible that nonecological speciation can be attributed) be considered a form of ecological isolation if it originates from an ecological mechanism. For example, the hybrid offspring may be seen as "less attractive" to mates due to intermediate sexual displays or differences in sexual communication. The end result is that the genes of each parental population are unable to intermix as they are carried by a hybrid who is unlikely to reproduce. This pattern of sexual selection against hybrid offspring has been found in Heliconius butterflies. The two species H. cydno and H. melpomene are distributed sympatrically in South America and hybridize infrequently. When they do hybridize, the species shows strong assortive mating due to the mimicry-evolved color pattern that hybrid offspring have an intermediate of. Similar patterns have been found in lacewings migrating patterns of Sylvia atricapilla bird populations, wolf spiders (Schizocosa ocreata and S. rovneri) and their courtship behaviors, sympatric benthic and limnetic sticklebacks (the Gasterosteus aculeatus complex), and the Panamanian butterflies Anartia fatima and A. amathea. Flowers involving pollinator discrimination against hybrids have shown this pattern as well, in monkey flowers (Erythranthe lewisii and Erythranthe cardinalis) and in two species of the Louisiana iris group, Iris fulva and I. hexagona. | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**DBase**
DBase:
dBase (also stylized dBASE) was one of the first database management systems for microcomputers and the most successful in its day. The dBase system includes the core database engine, a query system, a forms engine, and a programming language that ties all of these components together. dBase's underlying file format, the .dbf file, is widely used in applications needing a simple format to store structured data.Originally released as Vulcan for PTDOS in 1978, the CP/M port caught the attention of Ashton-Tate in 1980. They licensed it and re-released it as dBASE II, and later ported it to IBM PC computers running DOS. On the PC platform, in particular, dBase became one of the best-selling software titles for a number of years. A major upgrade was released as dBase III, and ported to a wider variety of platforms, adding UNIX, and VMS. By the mid-1980s, Ashton-Tate was one of the "big three" software publishers in the early business software market, the others being Lotus Development and WordPerfect.Starting in the mid-1980s, several companies produced their own variations on the dBase product and especially the dBase programming language. These included FoxBASE+ (later renamed FoxPro), Clipper, and other so-called xBase products. Many of these were technically stronger than dBase, but could not push it aside in the market. This changed with the poor reception of dBase IV, whose design and stability were so lacking that many users switched to other products.In the early 1990s, xBase products constituted the leading database platform for implementing business applications. The size and impact of the xBase market did not go unnoticed, and within one year, the three top xBase firms were acquired by larger software companies: Borland purchased Ashton-Tate Microsoft bought Fox Software Computer Associates acquired NantucketBy the opening decade of the 21st century, most of the original xBase products had faded from prominence and many had disappeared entirely. Products known as dBase still exist, owned by dBase LLC.
History:
Origins In the late 1960s, Fred Thompson at the Jet Propulsion Laboratory (JPL) was using a Tymshare product named RETRIEVE to manage a database of electronic calculators, which were at that time very expensive products. In 1971, Thompson collaborated with Jack Hatfield, a programmer at JPL, to write an enhanced version of RETRIEVE, which became the JPLDIS project. JPLDIS was written in FORTRAN on the UNIVAC 1108 mainframe, and was presented publicly in 1973. When Hatfield left JPL in 1974, Jeb Long took over his role.While working at JPL as a contractor, C. Wayne Ratliff entered the office football pool. He had no interest in the game as such, but felt he could win the pool by processing the post-game statistics found in newspapers. In order to do this, he turned his attention to a database system and, by chance, came across the documentation for JPLDIS. He used this as the basis for a port to PTDOS on his kit-built IMSAI 8080 microcomputer, and called the resulting system Vulcan (after the home planet of Mr. Spock on Star Trek).
History:
Ashton-Tate George Tate and Hal Lashlee had built two successful start-up companies: Discount Software, which was one of the first to sell PC software programs through the mail to consumers, and Software Distributors, which was one of the first wholesale distributors of PC software in the world. They entered into an agreement with Ratliff to market Vulcan, and formed Ashton-Tate (the name Ashton was chosen purely for marketing reasons) to do so. Ratliff ported Vulcan from PTDOS to CP/M. Hal Pawluk, who handled marketing for the nascent company, decided to change the name to the more business-like "dBase". Pawluk devised the use of lower case "d" and all-caps "BASE" to create a distinctive name. Pawluk suggested calling the new product version two ("II") to suggest it was less buggy than an initial release. dBase II was the result and became a standard CP/M application along with WordStar and SuperCalc.In 1981, IBM commissioned a port of dBase for the then-in-development PC. The resultant program was one of the initial pieces of software available when the IBM PC went on sale in the fall of 1981. dBase was one of a few "professional" programs on the platform then, and became a huge success. The customer base included not only end-users, but an increasing number of "value added resellers", or VARs, who purchased dBase, wrote applications with it, and sold the completed systems to their customers. The May 1983 release of dBase II RunTime further entrenched dBase in the VAR market by allowing the VARs to deploy their products using the lower-cost RunTime system.Although some critics stated that dBase was difficult to learn, its success created many opportunities for third parties. By 1984, more than 1,000 companies offered dBase-related application development, libraries of code to add functionality, applications using dBase II Runtime, consulting, training, and how-to books. A company in San Diego (today known as Advisor Media) premiered a magazine devoted to the professional use of dBase, Data Based Advisor; its circulation exceeded 35,000 after eight months. All of these activities fueled the rapid rise of dBase as the leading product of its type.
History:
dBase III As platforms and operating systems proliferated in the early 1980s, the company found it difficult to port the assembly language-based dBase to target systems. This led to a rewrite of the platform in the C programming language, using automated code conversion tools. The resulting code worked, but was essentially undocumented and inhuman in syntax, a problem that would prove to be serious in the future.In May 1984, the rewritten dBase III was released. Although reviewers widely panned its lowered performance, the product was otherwise well reviewed. After a few rapid upgrades, the system stabilized and was once again a best-seller throughout the 1980s, and formed the famous "application trio" of PC compatibles (dBase, Lotus 123, and WordPerfect). By the fall of 1984, the company had over 500 employees and was taking in US$40 million a year in sales (equivalent to $113 million in 2022), the vast majority from dBase products.
History:
Cloning There was also an unauthorized clone of dBase III called Rebus in the Soviet Union. Its adaptation to the Russian language was reduced to the mechanical replacement of the name, the russification of the help files and the correction of the sorting tables for the Russian language.
History:
dBase IV Introduced in 1988, after delays,dBase IV had "more than 300 new or improved features". By then, FoxPro had made inroads, and even dBase IV's support for Query by Example and SQL were not enough.Along the way, Borland, which had bought Ashton-Tate, brought out a revised dBase IV in 1992 but with a focus described as "designed for programmers" rather than "for ordinary users".
dBASE product range:
dBase, LLC products dBASE PLUS: A Windows-based database.
dBASE 2019: Successor of dBASE PLUS 12. Requires Windows Vista or later. Only 32-bit Windows Vista is supported, but 32 and 64-bit Windows Server 2012 are supported.
dBASE CLASSIC: dBASE V for DOS without DOS emulator, originally found in dBASE PLUS 9. Also includes original documentation included in the installation in PDF format.
dbDOS: A MS-DOS emulator.dbDOS PRO: Successor of dbDOS 1.5.1, starts with version 2.
dbDOS Open Source: Open source version of dbDOS.
dbDOSv: Successor of dbDOS PRO 7.dbfUtilities: .dbf file processing utilities.dbfCompare: Compares differences between tables.
dbfExport: Converts .dbf table to other file formats.
dbfImport: Converts other file formats into .dbf format.
dbfInspect: Read, modify, insert, delete, pack, and print using any dBASE IV and later tables.
SQL Utilities dumpSQL: Extracts all of the records of an existing table into a new table in the supported file formats.
moveSQL: Transfers all of the records of an existing table into a new table in the supported database formats.
dBase / xBase programming language:
For handling data, dBase provided detailed procedural commands and functions to open and traverse records in data files (e.g., USE, SKIP, GO TOP, GO BOTTOM, and GO recno), manipulate field values (REPLACE and STORE), and manipulate text strings (e.g., STR() and SUBSTR()), numbers, and dates.dBase is an application development language and integrated navigational database management system which Ashton-Tate labeled as "relational" but it did not meet the criteria defined by Dr. Edgar F. Codd's relational model. It used a runtime interpreter architecture, which allowed the user to execute commands by typing them in a command line "dot prompt". Similarly, program scripts (text files with PRG extensions) ran in the interpreter (with the DO command).Over time, Ashton-Tate's competitors introduced so-called clone products and compilers that had more robust programming features such as user-defined functions (UDFs), arrays for complex data handling. Ashton-Tate and its competitors also began to incorporate SQL, the ANSI/ISO standard language for creating, modifying, and retrieving data stored in relational database management systems.Eventually, it became clear that the dBase world had expanded far beyond Ashton-Tate. A "third-party" community formed, consisting of Fox Software, Nantucket, Alpha Software, Data Based Advisor Magazine, SBT and other application development firms, and major developer groups. Paperback Software launched the flexible and fast VP-Info with a unique built-in compiler. The community of dBase variants sought to create a dBase language standard, supported by IEEE committee X3J19 and initiative IEEE 1192. They said "xBase" to distinguish it from the Ashton-Tate product.Ashton-Tate saw the rise of xBase as an illegal threat to its proprietary technology. In 1988 they filed suit against Fox Software and Santa Cruz Operation (SCO) for copying dBase's "structure and sequence" in FoxBase+ (SCO marketed XENIX and UNIX versions of the Fox products). In December 1990, U.S. District judge Terry Hatter Jr. dismissed Ashton-Tate's lawsuit and invalidated Ashton-Tate's copyrights for not disclosing that dBase had been based, in part, on the public domain JPLDIS. In October 1991, while the case was still under appeal, Borland International acquired Ashton-Tate, and as one of the merger's provisions the U.S. Justice Department required Borland to end the lawsuit against Fox and allow other companies to use the dBase/xBase language without the threat of legal action.By the end of 1992, major software companies raised the stakes by acquiring the leading xBase products. Borland acquired Ashton-Tate's dBase products (and later WordTech's xBase products), Microsoft acquired Fox Software's FoxBASE+ and FoxPro products, and Computer Associates acquired Nantucket's Clipper products. Advisor Media built on its Data Based Advisor magazine by launching FoxPro Advisor and Clipper Advisor (and other) developer magazines and journals, and live conferences for developers. However, a planned dBase Advisor Magazine was aborted due to the market failure of dBase IV.By the year 2000, the xBase market had faded as developers shifted to new database systems and programming languages. Computer Associates (later known as CA) eventually dropped Clipper. Borland restructured and sold dBase. Of the major acquirers, Microsoft stuck with xBase the longest, evolving FoxPro into Visual FoxPro, but the product is no longer offered. In 2006 Advisor Media stopped its last-surviving xBase magazine, FoxPro Advisor. The era of xBase dominance has ended, but there are still xBase products. The dBase product line is now owned by dBase LLC which currently sells dBASE PLUS 12.3 and a DOS-based dBASE CLASSIC (dbDOS to run it on 64-bit Windows).Some open source implementations are available, such as Harbour, xHarbour, and Clip.In 2015, a new member of the xBase family was born: the XSharp (X#) language, maintained as an open source project with a compiler, its own IDE, and Microsoft Visual Studio integration. XSharp produces .NET assemblies and uses the familiar xBase language. The XSharp product was originally created by a group of four enthusiasts who have worked for the Vulcan.NET project in the past. The compiler is created on top of the Roslyn compiler code, the code behind the C# and VB compilers from Microsoft.
dBase / xBase programming language:
Programming examples Today, implementations of the dBase language have expanded to include many features targeted for business applications, including object-oriented programming, manipulation of remote and distributed data via SQL, Internet functionality, and interaction with modern devices.The following example opens an employee table ("empl"), gives every manager who supervises 1 or more employees a 10-percent raise, and then prints the names and salaries.
dBase / xBase programming language:
Note how one does not have to keep mentioning the table name. The assumed ("current") table stays the same until told otherwise. Because of its origins as an interpreted interactive language, dBase used a variety of contextual techniques to reduce the amount of typing needed. This facilitated incremental, interactive development but also made larger-scale modular programming difficult. A tenet of modular programming is that the correct execution of a program module must not be affected by external factors such as the state of memory variables or tables being manipulated in other program modules. Because dBase was not designed with this in mind, developers had to be careful about porting (borrowing) programming code that assumed a certain context and it would make writing larger-scale modular code difficult. Work-area-specific references were still possible using the arrow notation ("B->customer") so that multiple tables could be manipulated at the same time. In addition, if the developer had the foresight to name their tables appropriately, they could clearly refer to a large number of tables open at the same time by notation such as ("employee->salary") and ("vacation->start_date"). Alternatively, the alias command could be appended to the initial opening of a table statement which made referencing a table field unambiguous and simple. For example. one can open a table and assign an alias to it in this fashion, "use EMP alias Employee", and henceforth, refer to table variables as "Employee->Name".
dBase / xBase programming language:
Another notable feature is the re-use of the same clauses for different commands. For example, the FOR clause limits the scope of a given command. (It is somewhat comparable to SQL's WHERE clause.) Different commands such as LIST, DELETE, REPLACE, BROWSE, etc. could all accept a FOR clause to limit (filter) the scope of their activity. This simplifies the learning of the language.dBase was also one of the first business-oriented languages to implement string evaluation.
dBase / xBase programming language:
Here the "&" tells the interpreter to evaluate the string stored in "myMacro" as if it were programming code. This is an example of a feature that made dBase programming flexible and dynamic, sometimes called "meta ability" in the profession. This could allow programming expressions to be placed inside tables, somewhat reminiscent of formulas in spreadsheet software.However, it could also be problematic for pre-compiling and for making programming code secure from hacking. But, dBase tended to be used for custom internal applications for small and medium companies where the lack of protection against copying, as compared to compiled software, was often less of an issue.
Interactivity:
In addition to the dot-prompt, dBase III, III+, and IV came packaged with an ASSIST application to manipulate data and queries, as well as an APPSGEN application which allowed the user to generate applications without resorting to code writing, like a 4GL. The dBase IV APPSGEN tool was based largely on portions of an early CP/M product named Personal Pearl.
Niches:
Although the language has fallen out of favor as a primary business language, some find dBase an excellent interactive ad hoc data manipulation tool. Whereas SQL retrieves data sets from a relational database (RDBMS), with dBase one can more easily manipulate, format, analyze and perform calculations on individual records, strings, numbers, and so on in a step-by-step imperative (procedural) way instead of trying to figure out how to use SQL's declarative operations.Its granularity of operations is generally smaller than SQL, making it easier to split querying and table processing into easy-to-understand and easy-to-test parts. For example, one could insert a BROWSE operation between the filtering and the aggregation step to study the intermediate table or view (applied filter) before the aggregation step is applied.As an application development platform, dBase fills a gap between lower-level languages such as C, C++, and Java, and high-level proprietary 4GLs (fourth generation languages) and purely visual tools, providing relative ease-of-use for business people with less formal programming skill and high productivity for professional developers willing to trade off the low-level control.dBase remained a popular teaching tool even after sales slowed because the text-oriented commands were easier to present in printed training material than the mouse-oriented competitors. Mouse-oriented commands were added to the product over time, but the command language remained a popular de facto standard, while mousing commands tended to be vendor-specific.
File formats:
A major legacy of dBase is its .dbf file format, which has been adopted in a number of other applications. For example, the shapefile format, developed by ESRI for spatial data in its PC ArcInfo geographic information system, uses .dbf files to store feature attribute data.Microsoft recommends saving a Microsoft Works database file in the dBase file format so that it can be read by Microsoft Excel.A package is available for Emacs to read xbase files.LibreOffice and OpenOffice Calc can read and write all generic dbf files.dBase's database system was one of the first to provide a header section for describing the structure of the data in the file. This meant that the program no longer required advance knowledge of the data structure, but rather could ask the data file how it was structured. There are several variations on the .dbf file structure, and not all dBase-related products and .dbf file structures are compatible. VP-Info is unique in that it can read all variants of the dbf file structure.A second filetype is the .dbt file format for memo fields. While character fields are limited to 254 characters each, a memo field is a 10-byte pointer into a .dbt file which can include a much larger text field. dBase was very limited in its ability to process memo fields, but some other xBase languages such as Clipper treated memo fields as strings just like character fields for all purposes except permanent storage.dBase uses .ndx files for single indexes, and .mdx (multiple-index) files for holding between 1 and 48 indexes. Some xBase languages such as VP-Info include compatibility with .ndx files while others use different file formats such as .ntx used by Clipper and .idx/.cdx used by FoxPro or FlagShip. Later iterations of Clipper included drivers for .ndx, .mdx, .idx and .cdx indexes.
Reception:
Jerry Pournelle in July 1980 called Vulcan "infuriatingly excellent" because the software was powerful but the documentation was poor. He praised its speed and sophisticated queries, but said that "we do a lot of pounding at the table and screaming in rage at the documentation". | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**TRIP13**
TRIP13:
TRIP13 is a mammalian gene that encodes the thyroid receptor-interacting protein 13. In budding yeast, the analog for TRIP13 is PCH2. TRIP13 is a member of the AAA+ ATPase family, a family known for mechanical forces derived from ATP hydrolase reactions. The TRIP13 gene has been shown to interact with a variety of proteins and implicated in a few diseases, notably interacting with the ligand binding domain of thyroid hormone receptors, and may play a role in early-stage non-small cell lung cancer. However, recent evidence implicates TRIP13 in various cell cycle phases, including meiosis G2/Prophase and during the Spindle Assembly checkpoint (SAC). Evidence shows regulation to occur through the HORMA domains, including Hop1, Rev7, and Mad2. Of note, Mad2's involvement in the SAC is shown to be affected by TRIP13 Due to TRIP13's role in cell cycle arrest and progression, it may present opportunity as a therapeutic candidate for cancers.
Structure:
As an AAA+ ATPase, TRIP13 (and its PCH2 analog) forms homohexamers and interacts with ATP as an energy source. With respect to Hop1, PCH2 binds to and structurally changes Hop1, displacing the Hop1 from DNA. TRIP13/PCH2 interacts with ATP as a hydrolase, hydrolyzing phosphates to derive energy for conformational changes that can induce mechanical force on its substrate, Hop1 in the previous case. TRIP14/PCH2 is believed to have a single AAA+ ATPase domain. TRIP13/PCH2 also functions as a kinetochore protein that interacts with the silencing protein p31-Comet.
Role in meiosis G2/prophase:
Meiosis in mammalian cells have a series of checkpoints and steps that need to be properly regulated. TRIP13/PCH2 has been implicated in these processes in budding yeast as well, particularly in the meiosis G2/prophase stage. Double stranded breaks during meiosis is a key part of this phase and is impacted by TRIP13. The homologous recombination that occurs following these breaks requires a protein complex to influence and structure appropriate chromosomal pairing.
Role in meiosis G2/prophase:
In a paper by San-Segundo et al., localization assays and induced mutations in PCH2 in budding yeast was shown to be required for the meiotic checkpoint to prevent chromosome segregation when the recombination or chromosome synapsis are defective. TRIP13, PCH2's analog, was also shown to be required for the formation of the synaptonemal complex – the complex that structures chromosomal pairings. Without TRIP13, meiocytes had pericentric synaptic forks, fewer crossovers, and altered distribution of chiasma (the contact point between homologous chromosomes. For this synaptonemal complex (SC) formation, meiotic HORMADS need to be removed. For example, PCH2 was found to be needed to remove Hop1 from chromosomes during SC formation. Other HORMADs, such as HORMAD1 and HORMAD2, are also depleted from the chromosomal pairs with the help of TRIP13 in mice cells. Research shows a robust and varied role for TRIP13/PCH2 to remove various proteins for SC formation, thus allowing meiosis to continue. Further mechanistic evidence is needed to clarify other proteins affected by TRIP13 in meiosis G2/Prophase, and elucidate the wide ability to affect a multitude of proteins.
Role in spindle assembly checkpoint:
Like its role in meiosis, TRIP13/PCH2 is also implicated in mitosis, particularly in the metaphase-to-anaphase transition and the Spindle Assembly Checkpoint (SAC). Its function also has impacts on the Anaphase Promoting Complex (APC). To continue from metaphase to anaphase, the cell must ensure chromosomes are bioriented and properly structured in order for correct and error-free separation of sister chromatids. This process requires many proteins to ensure dynamic timing and consistent response. In order for progression, the APC must be activated, which upon activation degrade securing. The APC is activated by CDC20, a protein that is silenced by the mitotic checkpoint complex (MCC). Of interest in relation to TRIP13 is Mad2, which has two forms (open O-Mad2 and closed C-Mad2) (2). When kinetochores are unattached, O-Mad2 converts to C-Mad2, which is then able to latch to CDC20, and essentially sequester it preventing mitotic progression.Progression requires the disassembly of the MCC, which is found to be mediated by p31-Comet. This is through to occur in part by structural mimicry, where p31-Comet is structurally similar to C-Mad2. However, this process requires ATP, which is where TRIP13/PCH2 comes into play. Evidence shows that TRIP13/PCH2 uses p31-Comet as an adaptor protein to convert C-Mad2 into O-Mad2. However, the connection between TRIP13/PCH2 and the SAC is more nuanced. Experiments in human HeLa and HCT116 cells show that neither p31-Comet nor TRIP13 was particularly required for unperturbed mitosis, and that depleting P31-Comet only slightly impaired Mad2 inactivation. Additionally, research shows that without TRIP13, Mad2 exists exclusively in the closed form. Interestingly, in TRIP13 deficient cells, the SAC was unable to be inactivated and had a relatively short mitosis. This hints at the possibility that activation of the SAC and the formation of the MCC requires not only C-Mad2 but also the conversion of C-Mad2 to O-Mad2.
Implications in cancer:
Given TRIP13/PCH2's role in the correct biorientation of chromosomes during mitosis, it is unsurprising that it is connected to several cancers. In one instance, overexpression of TRIP13 has been shown to affect treatment resistance for Squamous cell carcinoma of the head and neck. Additionally, TRIP13 and Mad2 overexpression are correlated jointly in cancer. In relation to mitotic delays associated with Mad2 overexpression, overexpression of TRIP13 reduced and TRIP13 reduction increased the mitotic delay that Mad2 overexpression brings about. Furthermore, Mad2 over-expression and TRIP13 decrease inhibited proliferation in cells and tumor xenografts – presenting therapeutic value for TRIP13 reduction. | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**Rouché's theorem**
Rouché's theorem:
Rouché's theorem, named after Eugène Rouché, states that for any two complex-valued functions f and g holomorphic inside some region K with closed contour ∂K , if |g(z)| < |f(z)| on ∂K , then f and f + g have the same number of zeros inside K , where each zero is counted as many times as its multiplicity. This theorem assumes that the contour ∂K is simple, that is, without self-intersections. Rouché's theorem is an easy consequence of a stronger symmetric Rouché's theorem described below.
Usage:
The theorem is usually used to simplify the problem of locating zeros, as follows. Given an analytic function, we write it as the sum of two parts, one of which is simpler and grows faster than (thus dominates) the other part. We can then locate the zeros by looking at only the dominating part. For example, the polynomial z5+3z3+7 has exactly 5 zeros in the disk |z|<2 since 31 32 =|z5| for every |z|=2 , and z5 , the dominating part, has five zeros in the disk.
Geometric explanation:
It is possible to provide an informal explanation of Rouché's theorem.
Geometric explanation:
Let C be a closed, simple curve (i.e., not self-intersecting). Let h(z) = f(z) + g(z). If f and g are both holomorphic on the interior of C, then h must also be holomorphic on the interior of C. Then, with the conditions imposed above, the Rouche's theorem in its original (and not symmetric) form says that Notice that the condition |f(z)| > |h(z) − f(z)| means that for any z, the distance from f(z) to the origin is larger than the length of h(z) − f(z), which in the following picture means that for each point on the blue curve, the segment joining it to the origin is larger than the green segment associated with it. Informally we can say that the blue curve f(z) is always closer to the red curve h(z) than it is to the origin.
Geometric explanation:
The previous paragraph shows that h(z) must wind around the origin exactly as many times as f(z). The index of both curves around zero is therefore the same, so by the argument principle, f(z) and h(z) must have the same number of zeros inside C.
Geometric explanation:
One popular, informal way to summarize this argument is as follows: If a person were to walk a dog on a leash around and around a tree, such that the distance between the person and the tree is always greater than the length of the leash, then the person and the dog go around the tree the same number of times.
Applications:
Bounding roots Consider the polynomial z2+2az+b2 (where a>b>0 ). By the quadratic formula it has two zeros at −a±a2−b2 . Rouché's theorem can be used to obtain more precise positions of them. Since Rouché's theorem says that the polynomial has exactly one zero inside the disk |z|<b . Since −a−a2−b2 is clearly outside the disk, we conclude that the zero is −a+a2−b2 In general, a polynomial f(z)=anzn+⋯+a0 . If |ak|rk>∑j≠k|aj|rj for some r>0,k∈0:n , then by Rouche's theorem, the polynomial has exactly k roots inside B(0,r) This sort of argument can be useful in locating residues when one applies Cauchy's residue theorem.
Applications:
Fundamental theorem of algebra Rouché's theorem can also be used to give a short proof of the fundamental theorem of algebra. Let and choose R>0 so large that: Since anzn has n zeros inside the disk |z|<R (because R>0 ), it follows from Rouché's theorem that p also has the same number of zeros inside the disk.
One advantage of this proof over the others is that it shows not only that a polynomial must have a zero but the number of its zeros is equal to its degree (counting, as usual, multiplicity).
Another use of Rouché's theorem is to prove the open mapping theorem for analytic functions. We refer to the article for the proof.
Symmetric version:
A stronger version of Rouché's theorem was published by Theodor Estermann in 1962. It states: let K⊂G be a bounded region with continuous boundary ∂K . Two holomorphic functions f,g∈H(G) have the same number of roots (counting multiplicity) in K , if the strict inequality holds on the boundary ∂K.
The original version of Rouché's theorem then follows from this symmetric version applied to the functions f+g,f together with the trivial inequality |f(z)+g(z)|≥0 (in fact this inequality is strict since f(z)+g(z)=0 for some z∈∂K would imply |g(z)|=|f(z)| ).
The statement can be understood intuitively as follows.
Symmetric version:
By considering −g in place of g , the condition can be rewritten as |f(z)+g(z)|<|f(z)|+|g(z)| for z∈∂K Since |f(z)+g(z)|≤|f(z)|+|g(z)| always holds by the triangle inequality, this is equivalent to saying that |f(z)+g(z)|≠|f(z)|+|g(z)| on ∂K , which in turn means that for z∈∂K the functions f(z) and g(z) are non-vanishing and arg arg g(z) Intuitively, if the values of f and g never pass through the origin and never point in the same direction as z circles along ∂K , then f(z) and g(z) must wind around the origin the same number of times.
Proof of the symmetric form of Rouché's theorem:
Let C:[0,1]→C be a simple closed curve whose image is the boundary ∂K . The hypothesis implies that f has no roots on ∂K , hence by the argument principle, the number Nf(K) of zeros of f in K is i.e., the winding number of the closed curve f∘C around the origin; similarly for g. The hypothesis ensures that g(z) is not a negative real multiple of f(z) for any z = C(x), thus 0 does not lie on the line segment joining f(C(x)) to g(C(x)), and is a homotopy between the curves f∘C and g∘C avoiding the origin. The winding number is homotopy-invariant: the function is continuous and integer-valued, hence constant. This shows | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**Municipal broadband**
Municipal broadband:
Municipal broadband, sometimes referred to as a "Government-owned Network" or GON, is broadband Internet access offered by public entities. Services are often provided either fully or partially by local governments to residents within certain areas or jurisdictions. Common connection technologies include unlicensed wireless (Wi-Fi, wireless mesh networks), licensed wireless (such as WiMAX), and fiber optic cable. Many cities that previously deployed Wi-Fi based solutions, like Comcast and Charter Spectrum, are switching to municipal broadband. Municipal fiber-to-the-home networks are becoming more prominent because of increased demand for modern audio and video applications, which are increasing bandwidth requirements by 40% per year. Supporters of municipal broadband argue that when cities create their own internet and broadband, customers ultimately get faster internet speeds, lower prices, and better customer service than from internet service providers. The purpose of municipal broadband is to provide internet access to those who cannot afford internet from internet service providers and local governments are increasingly investing in said services for their communities.
Wireless public networks:
Wireless public municipal broadband networks avoid unreliable hub and spoke distribution models and use mesh networking instead. This method involves relaying radio signals throughout the whole city via a series of access points or radio transmitters, each of which is connected to at least two other transmitters. Mesh networks provide reliable user connections and are also faster to build and less expensive to run than the hub and spoke configurations. Internet connections can also be secured through the addition of a wireless router to an existing wired connection – a convenient method for Internet access provision in small centralized areas. Although wireless routers are generally reliable, their occasional failure means no Internet availability in that centralized area. This is why companies now use mesh networking in preference to hub and spoke configurations.
Wireless public networks:
Municipalities deploy networks in several ways. The five primary municipal broadband design approaches include: Full service (e.g., Chattanooga, Tennessee) Open access (e.g., Utah) Dark fiber (e.g., Stockholm, Sweden (also open access)) Incremental expansion (e.g., Santa Monica, California) Private-public partnership (e.g., Westminster, Maryland)Three basic models for the operation and funding of Wi-Fi networks have emerged: Networks designed solely for use by municipal services (fire, police, planners, engineers, libraries, etc.). Municipal funds are used to establish and run the network; Quasi-public networks for use by both municipal services and private users owned by the municipality but operated for profit by private companies ("private hot spots"). Such networks are funded by specially earmarked tax revenues then operated and maintained on a chargeable basis by private service providers; Private service providers using public property and rights of way for a fee. These allow for in-kind provision of private access to public rights of way to build-out and maintain private networks with a 'lease payment' or percentage of profits paid to the municipality.
Backhaul and wired infrastructure:
In Stockholm, the city-owned Stokab provides network infrastructure through dark fiber to several hundred service providers who provide various alternative services to end users. Reggefiber in the Netherlands performs a similar role. The Utah Telecommunication Open Infrastructure Agency provides service at one network layer higher through a fiber network. This system's capacity is wholesaled to fifteen service providers who in turn provide retail services to the market. A final model is a provision of all layers of service, such as in Chaska, Minnesota, where the city has built and operated a Wi-Fi Internet network that provides email and web hosting applications. These different models involve different public-private partnership arrangements, and varying levels of opportunity for private sector competition.
Backhaul and wired infrastructure:
Some municipalities face the struggle of acting as host sites for broadband infrastructure, but not having access themselves to the services it provides. For example, Mendocino County, California, has acted as a cable landing site that connects the United States to Japan ever since the Cold War period, when the site was moved to the remote area from San Francisco for security purposes. Since ISPs do not prioritize areas like Mendocino Country which are not highly profitable for them, the area’s proximity to necessary cable infrastructure has historically had little to no impact on the quality and availability of service in the area, which is still largely underserved to this day.
Advantages and disadvantages:
Supporters and opponents often assess municipal networks based on the supposed impact that the network will have on the local economy. Because of significant financial interests on either side of the issue, there is a variety of academic literature that supports and rejects the feasibility of a municipal network from an economic perspective.
Because municipal networks are publicly managed, they often lack the same profit incentive that private providers do. Proponents use this fact to argue that municipal broadband offers better prices, more equitable service, and increased competition in the broadband marketplace.
Advantages and disadvantages:
Price Proponents of municipal broadband describe how such networks can provide high-speed internet at lower rates than incumbent private internet service providers, with some municipalities even offering service for free at the point of connection. Opponents argue however that such networks are not actually cheaper to consumers when you factor in the higher costs of construction, higher cost of maintenance, and tax subsidization that occurs with publicly managed utilities.
Advantages and disadvantages:
Competition Proponents of municipal broadband also argue that the entrance of a public provider into a local market increases the competition which reduces prices and improves the quality of service. Opponents argue that the publicly funded networks have an unfair financial advantage that actually crowds out private investment and leads to long term reduction in competition and its associated problems.
Advantages and disadvantages:
Equitable Service Because of the different incentives and financing mechanisms that public providers have, municipal broadband has been marketed as a way of closing the digital divide by building more internet infrastructure in rural and low-income areas that private providers have historically avoided.
Opponents argue that there is no evidence that municipal broadband increases adoption of the Internet. They also argue that the funding spent on operating a public provider results in serious levels of waste that would have been better otherwise spent on subsidizing experienced private providers to offer service in rural and low-income areas.
Support:
In a 2004 White House report, President George W. Bush called for "universal, affordable access for broadband technology by the year 2007" and "plenty of technology choices when it comes to purchasing broadband".In 2000, the Federal Communications Commission endorsed municipal broadband as a "best practice" for bringing broadband to underserved communities.In 2021, President Joe Biden attempted to include direct provisions for municipal broadband in his $1 trillion infrastructure bill.The city of Philadelphia had the nonprofit Wireless Philadelphia accept bid from Earthlink to set up a network in 2004. "Philadelphia’s expectations were high; the city was eager, optimistic and, by the end of the decade, altogether too quick to chalk Wireless Philadelphia up as a failure. Still, the project was critical in laying the groundwork for future endeavors. Some of the hardware is still in use for an emergency communications network."The Free Press, the Media Access Project, and the ACLU have all come out in favor of municipal broadband.
Opposition:
The increasing prominence of municipal broadband has led to opposition. Critics argue that the construction and implementation of broadband service is an inappropriate use of public funds that can be invested elsewhere, and that on some occasions (such as EPB and iProvo), the high cost of maintaining the network is passed onto residents via either taxes or exorbitant rates, for services that may not necessarily meet the quality or reliability of a commercial ISP. In an op-ed, Larry Irving stated that "private sector ownership generally is more effective and efficient, promotes innovation, and helps assure freedom of speech and open networks". Trump administration FCC commissioner Michael O'Rielly argued that governments were infringing on their residents' First Amendment rights via prohibitions on "hateful" or "threatening" speech in the acceptable usage policies for their broadband networks—even though these restrictions are general, boilerplate terms also used by commercial ISPs.Lobbying efforts are often conducted by existing commercial ISPs, which promote state-level legislation—often based on a model act drafted by the industry and distributed by the conservative lobbying group American Legislative Exchange Council (ALEC)—that seek to frustrate the deployment or expansion of municipal broadband networks. These can include requiring that cities hold a referendum to seek approval, instituting regulatory burdens on the approval process or their operations (including requiring competing bids from private entities), restricting municipal broadband providers from expanding outside of their jurisdiction, restricting them to only being a wholesale provider for private entrants, prohibiting municipal broadband in cities above a certain population, and restricting access to utility poles (thus requiring underground digging, which can be costlier), among others.The successful campaign to hold a referendum on municipal broadband in Fort Collins, Colorado was opposed by the Colorado Cable Telecommunications Association (which included incumbent Comcast), who spent nearly $1 million on lobbying efforts, and the Colorado Chamber of Commerce, which was backed by CenturyLink and Comcast. Groups backed by the Koch brothers, including the Internet Freedom Coalition, and the Taxpayers Protection Alliance, have also been involved in lobbying efforts against municipal broadband projects.As of 2023, 16 states currently have laws that restrict or frustrate the establishment of municipal broadband networks. In May 2023, Colorado passed a bill to lift a law requiring referendums for municipal broadband networks; the bill received bipartisan support.
Finance:
In support of U.S. government agencies attempting to deploy broadband services more widely, the Bill and Melinda Gates Foundation detailed the cost estimates of providing "fiber optic connectivity to anchor institutions" in the United States in 2009. The institutions considered in the 2009 report were public schools, public libraries, hospitals and community colleges, with an estimated total cost of USD 5–10 billion.On February 17, 2009, the American Recovery and Reinvestment Act was passed in an effort to build the economy, assist in job creation and retention, and improve U.S. infrastructure. The Act allocated $4.7 billion to establish a Broadband Technology Opportunities Program as part of the National Telecommunications and Information Agency State Broadband Data and Development Grant Program. A portion of funding awards were allocated to extending and developing broadband services to reach rural and "underserved areas," as well as improving broadband access for public safety agencies.In July 2010. the District of Columbia was awarded $17.4 million in federal funds for its DC-Community Access Network.In 2010, the NTIA awarded a $126.3 million grant to West Virginia in order to improve the state's broadband infrastructure. The grant was particularly intended for public facilities such as hospitals, libraries, and schools. However, a report from West Virginia's legislative auditor suggested that the state had misused the stimulus money, and wasted an estimated $7.9–15 million on purchasing high-capacity Cisco routers that were often installed in smaller facilities which did not require such extensive network capacity. Governor Earl Ray Tomblin established a task force to investigate the overspending. In January 2014, the NTIA rejected a proposal by the State to use the remaining $2.5 million (plus other funding, including credits from Cisco for returning the oversized routers) to fund a middle mile network, for not reaching "programmatic requirements" and missing a deadline for its use.
United States policy:
The Federal Communications Commission (FCC) has addressed the question of whether a municipality was an "entity" under the Telecommunications Act which mandates that "No State or local statute or regulation, or other State or local legal requirement, may prohibit or have the effect of prohibiting the ability of any entity to provide any interstate or intrastate telecommunications service." 47 USC 253(a). The legal question revolved around whether a state could prevent a municipality, as its subordinate government body, from entering the telecommunication market. In the case of Nixon v. Missouri Municipal League (2004), the U.S. Supreme Court concluded that a municipality was not an entity under the Telecommunications Act of 1996 and that a state could determine what authority its own subordinate jurisdictions had.The 2014 case Verizon Communications Inc. v. FCC contained a ruling that the FCC had the jurisdiction to preempt state laws that restrict municipal broadband providers from extending their service beyond their current boundaries. In February 2015, the FCC voted to assert this jurisdiction to challenge municipal broadband laws in North Carolina and Tennessee, citing authority under Section 706 of the Telecommunications Act of 1996 to encourage the expansion of broadband by using "measures that promote competition in the local telecommunications market, or other regulating methods that remove barriers to infrastructure investment." The FCC declined to appeal.
Examples from outside the United States:
The Dutch capital, Amsterdam has its own municipal broadband project called: “Citynet Amsterdam.” This project is a partnership between the city and private investors that provides fiber cables to 40,000 buildings in the city.The European Commission has made broadband internet access a priority as part of its "Europe 2020 Strategy." Other objectives include 30 Mbit/s of Next Generation Networks coverage or more for all citizens and 100 Mbit/s or more for 50% of households by 2020. By 2025, the European Commission has goals to provide access to 1 Gbit/s for all schools, transport hubs, and main providers of public service, accessed to upgraded download speeds of 1 Gbit/s for all European households, and uninterrupted 5G wireless broadband coverage for all urban areas and major roads and railways.Different system models are more popular than others depending on the needs of the region. One example is "publicly run municipal network model" In this system, the local government installs and runs the broadband system. These systems are particularly common in Nordic countries. | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**Journal of Experimental Medicine**
Journal of Experimental Medicine:
Journal of Experimental Medicine is a monthly peer-reviewed medical journal published by Rockefeller University Press that publishes research papers and commentaries on the physiological, pathological, and molecular mechanisms that encompass the host response to disease. The journal prioritizes studies on intact organisms and has made a commitment to publishing studies on human subjects. Topics covered include immunology, inflammation, infectious disease, hematopoiesis, cancer, stem cells and vascular biology. The journal has no single editor-in-chief, but thirteen academic editors.
History:
The journal was established in 1896 at the Johns Hopkins School of Medicine by William H. Welch, the school's founder and also the first president of the Board of Scientific Directors of the Rockefeller Institute (since renamed Rockefeller University). From its inception, Welch edited the journal by himself—even editing manuscripts while attending baseball games. By March 1902, the editorial burden became too great for Welch, who stopped publishing papers and began stockpiling manuscripts and unanswered correspondence in his office, explaining the conspicuous absence of published papers from 1902 to 1904.In October 1902, Welch appealed to the board of the Rockefeller Institute to take over the journal. The transfer of ownership and publication responsibilities required the physical transfer of manuscripts from Welch's office, which fell to the director of the Rockefeller Institute, Simon Flexner, who carried the abandoned manuscripts from Baltimore to New York City in a suitcase.
History:
The first issue published by the Rockefeller Institute appeared in February 1905, with Flexner serving as editor, and the journal has been published regularly since then. Although the journal was adopted by the Rockefeller Institute as a venue for publication of the institute's own research, it also accepted submissions from outside. Even in the early years, more than half of the papers published in the journal came from external labs.
Online access:
An online archive of articles back to 1896 is available in text and PDF formats (material from 1996 and earlier is only available in PDF). Material over six months old is freely accessible and access to all papers is also provided free of charge to developing countries. All content is also deposited in PubMed Central, where it is available to the public six months after publication. Copyright to articles remains with the authors and third parties may re-use content after 6 months under the terms of a Creative Commons Attribution-Noncommercial-Share Alike 3.0 Unported license.
Impact factor:
According to the Journal Citation Reports, the journal received a 2020 impact factor of 14.307, ranking it seventh out of 177 journals in the category "Immunology" and fourth out of 189 journals in the category "Medicine, Research & Experimental". | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**Gravel cycling**
Gravel cycling:
Gravel cycling, gravel biking or gravel grinding is a sport, or a leisure activity, invented by Alfredo Pasin and Ilenia Lazzaro, in which participants ride bicycles mostly on gravel roads. Sometimes, specially designed gravel bikes are used; in other cases, any bicycle capable of covering the terrain can be used.
Gravel cycling:
Gravel cycling bridges the gap between road and mountain biking, combining the higher speed and efficiency of road cycling with the capability and freedom to ride on rough and loose terrain. While a small number of road races embrace long stretches of unpaved and gravel roads, notable the prestigious Italian classic Strade Bianche, gravel racing as a discipline has its own global series and world championship thanks to Ms Lazzaro as main promoter.
Gravel racing:
The distinguishing features of gravel races, also called gravel grinders, include long distances, often 160 to 320 kilometres (100 to 200 mi), mostly on gravel roads, and mass starts that include all categories of racers, similar to Gran Fondo rides.
The bicycles and courses in gravel racing vary widely, from road bicycles with wide tires used on smooth gravel roads to bicycles that are similar to mountain bikes used on courses that include technical trails.
Gravel racing:
History of gravel racing End of 19th century - beginning of 20th century In the early days of road bike racing, most roads were not paved, so most races were held primarily on unpaved/dirt/gravel roads.Due to road infrastructure improving with time, road bike racing shifted almost entirely to paved roads. In America the use of paved roads was largely influenced by a group of cyclists called League of American Wheelmen, who advocated for improving road conditions. Racing bikes got narrow tires and were no longer fit for off-road usage.
Gravel racing:
20th century Next to road bike racing, separate off-road cycling disciplines emerged. In autumn and winter in a few European countries, cyclo-cross is a popular professional sport. Cyclo-crossers ride off-road (on grass, sand, mud...) on a variant of a road bicycle, on a closed circuit during a relatively short time (1 hour), and jump or carry their bikes over obstacles or on steep climbs.
Gravel racing:
In the 1970s mountainbiking emerged.
21st century In the 21st century, riding and racing road bikes on gravel roads has gained popularity. Gravel cycling, as a mixture of road cycling, cyclo-cross and mountain biking became a new discipline of bicycle racing.
United States The revival started in the Mid-West of the USA, where gravel cycling evolved from cyclists riding long stretches of gravel and fire roads.
Some precursors to gravel racing in its current form include road races like the Tour of the Battenkill and Boulder–Roubaix (named after Paris–Roubaix) which are road races with gravel sections.
Gravel racing:
One of the premiere gravel races, Unbound Gravel in Emporia, Kansas (formerly called Dirty Kanza), started in 2006 and is 320 kilometres (200 mi) long.This race is a good example of how much gravel biking has grown in recent years: in 2006 there was a total of 34 riders that participated in the 320-kilometre (200 mi) race. In June 2019, 2,750 riders lucky enough to be picked from a lottery crossed the start line of the Dirty Kanza 200 and organizers had to introduce other mileage categories.
Gravel racing:
World Starting in 2010, the Pirate Cycling League in Lincoln, Nebraska started Gravel Worlds. Their grassroots movement gathered steam and as of 2022 is one of the largest gravel races in the world. In 2021, Gravel Worlds® received their registered trademark officially becoming THE Gravel Worlds. Thousands of riders from around the world race Gravel Worlds every year in Lincoln, Nebraska in late August. Champions of this event receive a world championship jersey, a pirate sword trophy, and the title of World Champion and "Captain of the Gravel Seas". In 2021, the UCI announced they will sanction in 2022 both the Gravel World Series with about 18 races in 4 continents, and the UCI Gravel World Championships. This first edition of the Championship will be held in Veneto in October and the Dutch champion, Mathieu van der Poel is amongst the favoris with Peter Sagan, Nicolas Roche and Alex Howes.
Gravel racing:
Racing rules and culture When taking Unbound Gravel as an example, there are checkpoints spaced about 80 kilometres (50 mi) apart for longer races, and riders must carry water and food, as well as fix their own tires and bikes.If riders receive outside support at any location other than official checkpoints it will result in immediate disqualification. Riders may assist other riders by any means and at any time.The culture of gravel biking has been a reason it has grown in popularity. Gravel races rarely call for a team of coaches and bicycle technicians because the courses susceptible to varying weather that is hard to train and prepare for. Gravel riders are generally focused on getting through a course rather than maintaining a pace during races. This give way to camaraderie on the trail and caters to a fun and relaxed atmosphere that is not always present in road and mountain bike races.
Gravel racing:
Other races USA Barry-Roubaix is an up to 160-kilometre (100 mi) road/off-road cycling race in Barry County, Michigan. The event is known as the World's Largest Gravel Road Race.
The annual Arkansaw High Country Race in June is an approximately 1,600-kilometre (1,000 mi) self-supported (bikepacking) gravel race through the Ouachita and Ozark National Forests, with approximately 84,000 feet (26,000 m) of total elevation.
Gravel racing:
Gravel Rankings and World Championship Gravel cycling as a whole has no governing body such as the UCI or USADA. Each race has its own rules, ethos, and character. Despite the balkanization of the races, a professional field of racers does exist, with each racer creating their own schedule of event to participate in. An independent organization called Pure Gravel has created a ranking system called the "Pure Gravel Power Rankings" in order to score and rank professional gravel racers across the myriad gravel races throughout the year. A king and Queen of gravel are crowned at the end of every calendar year.
Other major gravel events:
Europe In the UK, the Dirty Reiver is a 200-kilometre (120 mi) off-road timed cycling challenge that takes place in Hexham, England.
In Norway, Sweden and Finland, the Nordic Gravel Series are a series of gravel challenges
Gravel bicycle touring and bikepacking:
Riding on gravel roads has always been a part of bicycle touring, since its start in the 20th century. Also, already before the recent rise in popularity of gravel bikes, part of the cycle tourists were riding what we would now call gravel bikes. Before, these bicycles were often sold as dedicated touring bicycles, and seen as variants of randonneur bicycles.
Gravel bicycle touring and bikepacking:
Since the 2010s, gravel cycling and gravel bikes have been widely associated with one of the variants of bikepacking. Bikepacking is a form of traveling by bike with lightweight luggage, mostly without bicycle racks or panniers . The main difference between bicycle touring and bikepacking is the lightweight luggage and that bikepacking is usually off-road.
Gravel bikes:
The bicycles that cyclists use in gravel races and gravel rides can vary widely (can also be mountain bikes, cyclo-cross bicycles or racing bicycles with wider tires, depending on the conditions).
Gravel bikes:
However, since the 2010s, a dedicated type of bicycle is marketed as gravel bike to cover the new cycling discipline. Dedicated gravel group sets are available from three major vendors (Shimano, SRAM and Campagnolo). Compared to road groupsets, gravel groupsets tend to have features from MTB groupsets like a clutched rear derailleur (to keep chain tension on when riding on uneven surfaces to avoid chain jumping), lower gearing options (lower than 1:1, bigger sprockets and/or smaller chainrings, like for example a super-compact 48/32T or 46/30T chainset and a 11-34T cassette), and a wider side-to-side chainline for more tire clearance.Gravel bikes at first glance look very similar to road bikes with their drop bars and lack of suspension.
Gravel bikes:
Where gravel bikes differ from road bikes is that the bars are usually wider, geometry is adapted to be more comfortable riding offroad for long periods of time and modern gravel bikes will also feature a 1x drivetrain removing the front derailleur. Wheels are generally wider and forks and rear triangle will allow for much wider tyres to cope with the terrain and requirements of riding off-road. The relaxed geometry of mountain bikes is the foundation of gravel bike frames but gravel bikes are lighter, faster and more responsive than a mountain bike. Gravel bikes also use characteristics of both cyclocross and road bikes for better comfort on long rides and the wheel clearance to accommodate rides done in torrential conditions (heavy rain).
Gravel bikes:
Still, gravel bikes vary, and the different models cover a range between road racing bicycles and mountain bikes. | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**Axerra Networks**
Axerra Networks:
Axerra Networks is a leading provider of circuit emulation and service emulation solutions over packet access networks for mobile backhaul and business service delivery.
Company overview:
Axerra's pseudowire (PW) solutions enable mobile operators, cable MSOs, competitive access providers, and incumbent carriers to extend IP and legacy voice and data services in native format over Ethernet, IP, and MPLS networks.
The result is greater operational efficiency, new revenue opportunities, and a smooth migration strategy to a single converged network without losing any revenue streams from profitable legacy services.
Axerra's solutions enable all service providers to benefit from pseudowires by converting any access network (carrier ethernet, broadband wireless including WiMAX, cable HFC, xDSL, xPON, etc.) into a multiservice alternative to TDM access.
Axerra Networks is based in Tel Aviv, Israel with offices in the US, Russia and Poland.
In 2010, DragonWave acquired the company for $9.5 million.
Technology overview:
Pseudowires (PW) enable providers to roll out a full complement of both emerging and legacy services from their IP and MPLS networks.
PW technology is a hot topic because it furnishes greater operational efficiency while simultaneously enabling a smooth migration strategy to a single converged network, without stranding any revenue streams from legacy services.
Technology overview:
The term 'pseudowire' comes from the IETF's Pseudowire Emulation Edge-to-Edge (PWE3) working group, which is chartered to define a mechanism that emulate the essential attributes of services such as ATM, Frame Relay, Ethernet or Circuit Emulation over a Packet Switched Network (PSN). The goals of PWE3 are similar in many ways to what we have known for over a decade as 'multiservice.' The difference is that Ethernet, IP and MPLS have replaced ATM as the fundamental switching and transport technology. PWE3 working group was originally formed in mid-2001, although pseudowires were originally known as private wires (a little-known fact). Even so, the ideas behind pseudowires did not originate in 2001. Axerra Networks has been at the forefront of envisioning multiservice using Ethernet, IP and MPLS since before 1999. Axerra coined the terms Multiservice over IP (MSoIP), Circuit Emulation Service over IP (CESoIP), Frame Relay over IP (FRoIP), and ATM over IP (ATMoIP) – and still owns the Internet domain names and trademarks for these terms. Thus, Axerra has been an early innovator of pseudowire technology and a leading contributor to the PWE3 standardization efforts rapidly reaching fruition in PWE3, as well as ITU-T, the Broadband Forum (BBF), and the Metro Ethernet Forum (MEF), bode well for the adoption of pseudowire technology by the service provider industry. Axerra understands that pseudowire is simply a new term for the next generation of multiservice – multiservice over IP and MPLS. Based on its experience in this technology, predating even its new name, and based on contributions to these standardization efforts, Axerra is well positioned to lead service providers' uptake of pseudowires networking. | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**Text Retrieval Conference**
Text Retrieval Conference:
The Text REtrieval Conference (TREC) is an ongoing series of workshops focusing on a list of different information retrieval (IR) research areas, or tracks. It is co-sponsored by the National Institute of Standards and Technology (NIST) and the Intelligence Advanced Research Projects Activity (part of the office of the Director of National Intelligence), and began in 1992 as part of the TIPSTER Text program. Its purpose is to support and encourage research within the information retrieval community by providing the infrastructure necessary for large-scale evaluation of text retrieval methodologies and to increase the speed of lab-to-product transfer of technology.
Text Retrieval Conference:
TREC's evaluation protocols have improved many search technologies. A 2010 study estimated that "without TREC, U.S. Internet users would have spent up to 3.15 billion additional hours using web search engines between 1999 and 2009." Hal Varian the Chief Economist at Google wrote that "The TREC data revitalized research on information retrieval. Having a standard, widely available, and carefully constructed set of data laid the groundwork for further innovation in this field."Each track has a challenge wherein NIST provides participating groups with data sets and test problems. Depending on track, test problems might be questions, topics, or target extractable features. Uniform scoring is performed so the systems can be fairly evaluated. After evaluation of the results, a workshop provides a place for participants to collect together thoughts and ideas and present current and future research work.Text Retrieval Conference started in 1992, funded by DARPA (US Defense Advanced Research Project) and run by NIST. Its purpose was to support research within the information retrieval community by providing the infrastructure necessary for large-scale evaluation of text retrieval methodologies.
Goals:
Encourage retrieval search based on large text collections Increase communication among industry, academia, and government by creating an open forum for the exchange of research ideas Speed the transfer of technology from research labs into commercial products by demonstrating substantial improvements retrieval methodologies on real world problems To increase the availability of appropriate evaluation techniques for use by industry and academia including development of new evaluation techniques more applicable to current systemsTREC is overseen by a program committee consisting of representatives from government, industry, and academia. For each TREC, NIST provide a set of documents and questions. Participants run their own retrieval system on the data and return to NIST a list of retrieved top-ranked documents .NIST pools the individual result judges the retrieved documents for correctness and evaluates the results. The TREC cycle ends with a workshop that is a forum for participants to share their experiences.
Relevance judgments in TREC:
TREC uses binary relevance criterion that is either the document is relevant or not relevant. Since size of TREC collection is large, it is impossible to calculate the absolute recall for each query. In order to assess the relevance of documents in relation to a query, TREC uses a specific method call pooling for calculating relative recall. All the relevant documents that occurred in the top 100 documents for each system and for each query are combined to produce a pool of relevant documents. Recall being the proportion of the pool of relevant documents that a single system retrieved for a query topic.
Various TRECs:
In 1992 TREC-1 was held at NIST. The first conference attracted 28 groups of researchers from academia and industry. It demonstrated a wide range of different approaches to the retrieval of text from large document collections .Finally TREC1 revealed the facts that automatic construction of queries from natural language query statements seems to work. Techniques based on natural language processing were no better no worse than those based on vector or probabilistic approach.
Various TRECs:
TREC2 Took place in August 1993. 31 group of researchers participated in this. Two types of retrieval were examined. Retrieval using an ‘ad hoc’ query and retrieval using a ‘routing' query In TREC-3 a small group experiments worked with Spanish language collection and others dealt with interactive query formulation in multiple databases TREC-4 they made even shorter to investigate the problems with very short user statements TREC-5 includes both short and long versions of the topics with the goal of carrying out deeper investigation into which types of techniques work well on various lengths of topics In TREC-6 Three new tracks speech, cross language, high precision information retrieval were introduced. The goal of cross language information retrieval is to facilitate research on system that are able to retrieve relevant document regardless of language of the source document TREC-7 contained seven tracks out of which two were new Query track and very large corpus track. The goal of the query track was to create a large query collection TREC-8 contain seven tracks out of which two –question answering and web tracks were new. The objective of QA query is to explore the possibilities of providing answers to specific natural language queries TREC-9 Includes seven tracks In TREC-10 Video tracks introduced Video tracks design to promote research in content based retrieval from digital video In TREC-11 Novelty tracks introduced. The goal of novelty track is to investigate systems abilities to locate relevant and new information within the ranked set of documents returned by a traditional document retrieval system TREC-12 held in 2003 added three new tracks; Genome track, robust retrieval track, HARD (Highly Accurate Retrieval from Documents)
Tracks:
Current tracks New tracks are added as new research needs are identified, this list is current for TREC 2018.
CENTRE Track – Goal: run in parallel CLEF 2018, NTCIR-14, TREC 2018 to develop and tune an IR reproducibility evaluation protocol (new track for 2018).
Common Core Track – Goal: an ad hoc search task over news documents.
Complex Answer Retrieval (CAR) – Goal: to develop systems capable of answering complex information needs by collating information from an entire corpus.
Incident Streams Track – Goal: to research technologies to automatically process social media streams during emergency situations (new track for TREC 2018).
The News Track – Goal: partnership with The Washington Post to develop test collections in news environment (new for 2018).
Precision Medicine Track – Goal: a specialization of the Clinical Decision Support track to focus on linking oncology patient data to clinical trials.
Real-Time Summarization Track (RTS) – Goal: to explore techniques for real-time update summaries from social media streams.
Past tracks Chemical Track – Goal: to develop and evaluate technology for large scale search in chemistry-related documents, including academic papers and patents, to better meet the needs of professional searchers, and specifically patent searchers and chemists.
Clinical Decision Support Track – Goal: to investigate techniques for linking medical cases to information relevant for patient care Contextual Suggestion Track – Goal: to investigate search techniques for complex information needs that are highly dependent on context and user interests.
Crowdsourcing Track – Goal: to provide a collaborative venue for exploring crowdsourcing methods both for evaluating search and for performing search tasks.
Genomics Track – Goal: to study the retrieval of genomic data, not just gene sequences but also supporting documentation such as research papers, lab reports, etc. Last ran on TREC 2007.
Dynamic Domain Track – Goal: to investigate domain-specific search algorithms that adapt to the dynamic information needs of professional users as they explore in complex domains.
Enterprise Track – Goal: to study search over the data of an organization to complete some task. Last ran on TREC 2008.
Entity Track – Goal: to perform entity-related search on Web data. These search tasks (such as finding entities and properties of entities) address common information needs that are not that well modeled as ad hoc document search.
Cross-Language Track – Goal: to investigate the ability of retrieval systems to find documents topically regardless of source language. After 1999, this track spun off into CLEF.
FedWeb Track – Goal: to select best resources to forward a query to, and merge the results so that most relevant are on the top.
Federated Web Search Track – Goal: to investigate techniques for the selection and combination of search results from a large number of real on-line web search services.
Filtering Track – Goal: to binarily decide retrieval of new incoming documents given a stable information need.
HARD Track – Goal: to achieve High Accuracy Retrieval from Documents by leveraging additional information about the searcher and/or the search context.
Interactive Track – Goal: to study user interaction with text retrieval systems.
Knowledge Base Acceleration (KBA) Track – Goal: to develop techniques to dramatically improve the efficiency of (human) knowledge base curators by having the system suggest modifications/extensions to the KB based on its monitoring of the data streams, created the KBA streamcorpus, organized by Diffeo.
Legal Track – Goal: to develop search technology that meets the needs of lawyers to engage in effective discovery in digital document collections.
LiveQA Track – Goal: to generate answers to real questions originating from real users via a live question stream, in real time.
Medical Records Track – Goal: to explore methods for searching unstructured information found in patient medical records.
Microblog Track – Goal: to examine the nature of real-time information needs and their satisfaction in the context of microblogging environments such as Twitter.
Natural language processing Track – Goal: to examine how specific tools developed by computational linguists might improve retrieval.
Novelty Track – Goal: to investigate systems' abilities to locate new (i.e., non-redundant) information.
OpenSearch Track – Goal: to explore an evaluation paradigm for IR that involves real users of operational search engines. For first year of the track the task was ad hoc Academic Search.
Question Answering Track – Goal: to achieve more information retrieval than just document retrieval by answering factoid, list and definition-style questions.
Real-Time Summarization Track – Goal: to explore techniques for constructing real-time update summaries from social media streams in response to users' information needs.
Robust Retrieval Track – Goal: to focus on individual topic effectiveness.
Relevance Feedback Track – Goal: to further deep evaluation of relevance feedback processes.
Session Track – Goal: to develop methods for measuring multiple-query sessions where information needs drift or get more or less specific over the session.
Spam Track – Goal: to provide a standard evaluation of current and proposed spam filtering approaches.
Tasks Track – Goal: to test whether systems can induce the possible tasks users might be trying to accomplish given a query.
Temporal Summarization Track – Goal: to develop systems that allow users to efficiently monitor the information associated with an event over time.
Terabyte Track – Goal: to investigate whether/how the IR community can scale traditional IR test-collection-based evaluation to significantly large collections.
Total Recall Track – Goal: to evaluate methods to achieve very high recall, including methods that include a human assessor in the loop.
Video Track – Goal: to research in automatic segmentation, indexing, and content-based retrieval of digital video. In 2003, this track became its own independent evaluation named TRECVID Web Track – Goal: to explore information seeking behaviors common in general web search.
Tracks:
Related events In 1997, a Japanese counterpart of TREC was launched (first workshop in 1999), called NTCIR (NII Test Collection for IR Systems), and in 2000, CLEF, a European counterpart, specifically vectored towards the study of cross-language information retrieval was launched. Forum for Information Retrieval Evaluation (FIRE) started in 2008 with the aim of building a South Asian counterpart for TREC, CLEF, and NTCIR,
Conference contributions to search effectiveness:
NIST claims that within the first six years of the workshops, the effectiveness of retrieval systems approximately doubled. The conference was also the first to hold large-scale evaluations of non-English documents, speech, video and retrieval across languages. Additionally, the challenges have inspired a large body of publications. Technology first developed in TREC is now included in many of the world's commercial search engines. An independent report by RTII found that "about one-third of the improvement in web search engines from 1999 to 2009 is attributable to TREC. Those enhancements likely saved up to 3 billion hours of time using web search engines. ... Additionally, the report showed that for every $1 that NIST and its partners invested in TREC, at least $3.35 to $5.07 in benefits were accrued to U.S. information retrieval researchers in both the private sector and academia." While one study suggests that the state of the art for ad hoc search did not advance substantially in the decade preceding 2009, it is referring just to search for topically relevant documents in small news and web collections of a few gigabytes. There have been advances in other types of ad hoc search. For example, test collections were created for known-item web search which found improvements from the use of anchor text, title weighting and url length, which were not useful techniques on the older ad hoc test collections. In 2009, a new billion-page web collection was introduced, and spam filtering was found to be a useful technique for ad hoc web search, unlike in past test collections.
Conference contributions to search effectiveness:
The test collections developed at TREC are useful not just for (potentially) helping researchers advance the state of the art, but also for allowing developers of new (commercial) retrieval products to evaluate their effectiveness on standard tests. In the past decade, TREC has created new tests for enterprise e-mail search, genomics search, spam filtering, e-Discovery, and several other retrieval domains.TREC systems often provide a baseline for further research. Examples include: Hal Varian, Chief Economist at Google, says Better data makes for better science. The history of information retrieval illustrates this principle well," and describes TREC's contribution.
Conference contributions to search effectiveness:
TREC's Legal track has influenced the e-Discovery community both in research and in evaluation of commercial vendors.
The IBM researcher team building IBM Watson (aka DeepQA), which beat the world's best Jeopardy! players, used data and systems from TREC's QA Track as baseline performance measurements.
Participation:
The conference is made up of a varied, international group of researchers and developers. In 2003, there were 93 groups from both academia and industry from 22 countries participating. | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**Nullspace property**
Nullspace property:
In compressed sensing, the nullspace property gives necessary and sufficient conditions on the reconstruction of sparse signals using the techniques of ℓ1 -relaxation. The term "nullspace property" originates from Cohen, Dahmen, and DeVore. The nullspace property is often difficult to check in practice, and the restricted isometry property is a more modern condition in the field of compressed sensing.
The technique of:
ℓ1 -relaxation The non-convex ℓ0 -minimization problem, min x‖x‖0 subject to Ax=b is a standard problem in compressed sensing. However, ℓ0 -minimization is known to be NP-hard in general. As such, the technique of ℓ1 -relaxation is sometimes employed to circumvent the difficulties of signal reconstruction using the ℓ0 -norm. In ℓ1 -relaxation, the ℓ1 problem, min x‖x‖1 subject to Ax=b is solved in place of the ℓ0 problem. Note that this relaxation is convex and hence amenable to the standard techniques of linear programming - a computationally desirable feature. Naturally we wish to know when ℓ1 -relaxation will give the same answer as the ℓ0 problem. The nullspace property is one way to guarantee agreement.
Definition:
An m×n complex matrix A has the nullspace property of order s , if for all index sets S with s=|S|≤n we have that: ‖ηS‖1<‖ηSC‖1 for all ker A∖{0}
Recovery Condition:
The following theorem gives necessary and sufficient condition on the recoverability of a given s -sparse vector in Cn . The proof of the theorem is a standard one, and the proof supplied here is summarized from Holger Rauhut.
Recovery Condition:
Theorem: Let A be a m×n complex matrix. Then every s -sparse signal x∈Cn is the unique solution to the ℓ1 -relaxation problem with b=Ax if and only if A satisfies the nullspace property with order s Proof: For the forwards direction notice that ηS and −ηSC are distinct vectors with A(−ηSC)=A(ηS) by the linearity of A , and hence by uniqueness we must have ‖ηS‖1<‖ηSC‖1 as desired. For the backwards direction, let x be s -sparse and z another (not necessary s -sparse) vector such that z≠x and Az=Ax . Define the (non-zero) vector η=x−z and notice that it lies in the nullspace of A . Call S the support of x , and then the result follows from an elementary application of the triangle inequality: ‖x‖1≤‖x−zS‖1+‖zS‖1=‖ηS‖1+‖zS‖1<‖ηSC‖1+‖zS‖1=‖−zSC‖1+‖zS‖1=‖z‖1 , establishing the minimality of x . ◻ | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**Simtest**
Simtest:
SIMTEST is a computerized adaptive test (CAT) of foreign language ability designed and developed at the Universitat Autònoma de Barcelona in Catalonia, Spain. It classifies examinees according to 6 levels of proficiency as defined in the Council of Europe document: “A Common European Framework of Reference for Languages (CEFR): learning, teaching, assessment” (Cambridge University Press, 2001).
Simtest:
SIMTEST has been developed for both placement and certification purposes. Version 1 was available in local for Windows and current version is available on-line. It consists of 4 component tests that may be used - according to the testing context or institutional requirements - to test knowledge of vocabulary, grammar and language functions in addition to reading and listening comprehension. The only non-CAT component consists of a series of 4 C-Tests (a cloze procedure developed in the 1980s at Gerhard-Mercator-Universität Duisburg in Germany - based on theories of language redundancy relating to Gestalt theory). An initial estimation of the level of language proficiency detected by the C-Tests may be used as an entry point to the CAT components. Multiple choice items are presented on a CAT administration based on an algorithm described by Henning (1987). | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**IBM Lotus Organizer**
IBM Lotus Organizer:
Lotus Organizer is a discontinued personal information manager (PIM). It was initially developed by Threadz, a small British software house, reaching version 3.0. Organizer was subsequently acquired by Lotus Development Corporation, for whom the package was a Windows-based replacement for Lotus Agenda. For several years it was the unquestioned market leader until it was gradually overtaken by Microsoft Outlook.
Organizer is notable for using the ″leather-bound personal organizer″ graphical metaphor for its user interface. It is often bundled within Lotus SmartSuite.
Status:
On 14 May 2013, IBM announced the immediate "withdrawal and discontinuance of support" of Lotus SmartSuite, Lotus Organizer and Lotus 123.Version 6.1 was the last version. It supported Windows 2000, Windows XP, Windows Vista , Windows 7, and Windows 10.
Versions:
Microsoft Windows Organizer was a part of Lotus SmartSuite, but was also sold as a single application. The latest releases of SmartSuite did not include the current version of Organizer; it was sold separately only.
Versions up to 2 were 16-bit programs. Later versions are 32-bit programs.
IBM OS/2 The first OS/2 version was released in 1998. Until then, the Windows 16-bit version had been used. The last version is 1.7 from 2001. Later revisions of SmartSuite did not upgrade Organizer, although some fixes have been made.
Organizer for OS/2 uses the .or4 file format. This means that it cannot exchange data files with the later Windows versions, other than by importing and exporting data.
The features and user interface for Organizer for OS/2 are similar to that of Organizer 97 for Windows. It lacks later improvements, such as importing and exporting vCard and iCalendar files, and synchronisation with PDAs.
Mac OS Lotus Organizer 97 GS was released for classic Mac OS in 1997 with features similar to the Windows version, including integration with Lotus Notes calendars and address books. | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**Hass–Bender oxidation**
Hass–Bender oxidation:
In organic chemistry, the Hass–Bender oxidation (also called the Hass–Bender carbonyl synthesis) is an organic oxidation reaction that converts benzyl halides into benzaldehydes using the sodium salt of 2-nitropropane as the oxidant. This name reaction is named for Henry B. Hass and Myron L. Bender, who first reported it in 1949.
Hass–Bender oxidation:
The reaction process begins with the deprotonation of 2-nitropropane at the α carbon to form a resonance-stabilized anion. This compound then initiates an SN2 reaction to displace the benzyl halide. Unlike in the nitroaldol reaction, where the deprotonated carbon of the nitroalkyl group is the nucleophilic atom, it is instead an oxygen of the nitro itself that attacks the benzylic carbon. The O-benzyl structure then undergoes a pericyclic reaction to produce a benzaldehyde, with dimethyloxime as a byproduct.
Hass–Bender oxidation:
Although originally developed for benzyl compounds, the reaction also works for allyl halides, giving the respective α,β-enones and enals. | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**Payment Card Industry Data Security Standard**
Payment Card Industry Data Security Standard:
The Payment Card Industry Data Security Standard (PCI DSS) is an information security standard used to handle credit cards from major card brands. The standard is administered by the Payment Card Industry Security Standards Council, and its use is mandated by the card brands. It was created to better control cardholder data and reduce credit card fraud. Validation of compliance is performed annually or quarterly with a method suited to the volume of transactions: Self-assessment questionnaire (SAQ) Firm-specific Internal Security Assessor (ISA) External Qualified Security Assessor (QSA)
History:
The major card brands had five different security programs: Visa's Cardholder Information Security Program Mastercard's Site Data Protection American Express's Data Security Operating Policy Discover's Information Security and Compliance JCB's Data Security ProgramThe intentions of each were roughly similar: to create an additional level of protection for card issuers by ensuring that merchants meet minimum levels of security when they store, process, and transmit cardholder data. To address interoperability problems among the existing standards, the combined effort by the principal credit-card organizations resulted in the release of version 1.0 of PCI DSS in December 2004. PCI DSS has been implemented and followed worldwide.
History:
The Payment Card Industry Security Standards Council (PCI SSC) was then formed, and these companies aligned their policies to create the PCI DSS. MasterCard, American Express, Visa, JCB International and Discover Financial Services established the PCI SSC in September 2006 as an administrative and governing entity which mandates the evolution and development of the PCI DSS. Independent private organizations can participate in PCI development after they register. Each participating organization joins a SIG (Special Interest Group) and contributes to activities mandated by the group. The following versions of the PCI DSS have been made available:
Requirements:
The PCI DSS has twelve requirements for compliance, organized into six related groups known as control objectives: Build and maintain a secure network and systems Protect cardholder data Maintain a vulnerability management program Implement strong access-control measures Regularly monitor and test networks Maintain an information security policyEach PCI DSS version has divided these six requirement groups differently, but the twelve requirements have not changed since the inception of the standard. Each requirement and sub-requirement is divided into three sections: PCI DSS requirements: Define the requirement. The PCI DSS endorsement is made when the requirement is implemented.
Requirements:
Testing: The processes and methodologies carried out by the assessor for the confirmation of proper implementation.
Guidance: Explains the purpose of the requirement and the corresponding content, which can assist in its proper definition.In version 3.2.1 of the PCI DSS, the twelve requirements are: Install and maintain a firewall system to protect cardholder data.
Avoid vendor-supplied defaults for system passwords and other security parameters.
Protect stored cardholder data.
Encrypt transmission of cardholder data on open, public networks.
Protect all systems against malware, and update anti-virus software or programs.
Develop and maintain secure systems and applications.
Restrict access to cardholder data by business need to know.
Identify and authenticate access to system components.
Restrict physical access to cardholder data.
Track and monitor access to network resources and cardholder data.
Regularly test security systems and processes.
Maintain an information security policy which addresses information security for all personnel.
Updates and supplemental information:
The PCI SSC (Payment Card Industry Security Standards Council) has released supplemental information to clarify requirements, which includes: Information Supplement: Requirement 11.3 Penetration Testing Information Supplement: Requirement 6.6 Code Reviews and Application Firewalls Clarified Navigating the PCI DSS - Understanding the Intent of the Requirements PCI DSS Wireless Guidelines PCI DSS Applicability in an EMV Environment Prioritized Approach for PCI DSS Prioritized Approach Tool PCI DSS Quick Reference Guide PCI DSS Virtualization Guidelines PCI DSS Tokenization Guidelines PCI DSS 2.0 Risk Assessment Guidelines The lifecycle for Changes to the PCI DSS and PA-DSS Guidance for PCI DSS Scoping and Segmentation PCI DSS v4.0 Resource Hub
Reporting levels:
Companies subject to PCI DSS standards must be PCI-compliant; how they prove and report their compliance is based on their annual number of transactions and how the transactions are processed. An acquirer or payment brand may manually place an organization into a reporting level at its discretion. Merchant levels are: Level 1 – Over six million transactions annually Level 2 – Between one and six million transactions Level 3 – Between 20,000 and one million transactions, and all e-commerce merchants Level 4 – Less than 20,000 transactionsEach card issuer maintains a table of compliance levels and a table for service providers.
Compliance validation:
Compliance validation involves the evaluation and confirmation that the security controls and procedures have been implemented according to the PCI DSS. Validation occurs through an annual assessment, either by an external entity, or by self-assessment.
Compliance validation:
Report on Compliance A Report on Compliance (ROC) is conducted by a PCI Qualified Security Assessor (QSA) and is intended to provide independent validation of an entity's compliance with the PCI DSS standard. A completed ROC results in two documents: a ROC Reporting Template populated with detailed explanation of the testing completed, and an Attestation of Compliance (AOC) documenting that a ROC has been completed and the overall conclusion of the ROC.
Compliance validation:
Self-Assessment Questionnaire The PCI DSS Self-Assessment Questionnaire (SAQ) is a validation tool intended for small to medium sized merchants and service providers to assess their own PCI DSS compliance status. There are multiple types of SAQ, each with a different length depending on the entity type and payment model used. Each SAQ question has a yes-or-no answer, and any "no" response requires the entity to indicate its future implementation. As with ROCs, an attestation of compliance (AOC) based on the SAQ is also completed.
Compliance validation:
Security Assessors The PCI Security Standards Council maintains a program to certify companies and individuals to perform assessment activities.
Qualified Security Assessor A Qualified Security Assessor (QSA) is an individual certified by the PCI Security Standards Council to validate another entity's PCI DSS compliance. QSAs must be employed and sponsored by a QSA Company, which also must be certified by the PCI Security Standards Council.
Compliance validation:
Internal Security Assessor An Internal Security Assessor (ISA) is an individual who has earned a certificate from the PCI Security Standards Council for their sponsoring organization, and can conduct PCI self-assessments for their organization. The ISA program was designed to help Level 2 merchants meet Mastercard compliance validation requirements. ISA certification empowers an individual to conduct an appraisal of his or her association and propose security solutions and controls for PCI DSS compliance. ISAs are in charge of cooperation and participation with QSAs.
Compliance versus validation of compliance:
Although the PCI DSS must be implemented by all entities which process, store or transmit cardholder data, formal validation of PCI DSS compliance is not mandatory for all entities. Visa and Mastercard require merchants and service providers to be validated according to the PCI DSS; Visa also offers a Technology Innovation Program (TIP), an alternative program which allows qualified merchants to discontinue the annual PCI DSS validation assessment. Merchants are eligible if they take alternative precautions against fraud, such as the use of EMV or point-to-point encryption.Issuing banks are not required to undergo PCI DSS validation, although they must secure sensitive data in a PCI DSS-compliant manner. Acquiring banks must comply with PCI DSS and have their compliance validated with an audit. In a security breach, any compromised entity which was not PCI DSS-compliant at the time of the breach may be subject to additional penalties (such as fines) from card brands or acquiring banks.
Legislation in the United States:
Compliance with PCI DSS is not required by federal law in the United States, but the laws of some states refer to PCI DSS directly or make equivalent provisions. Legal scholars Edward Morse and Vasant Raval have said that by enshrining PCI DSS compliance in legislation, card networks reallocated the cost of fraud from card issuers to merchants.
Legislation in the United States:
In 2007, Minnesota enacted a law prohibiting the retention of some types of payment-card data more than 48 hours after authorization of a transaction. Nevada incorporated the standard into state law two years later, requiring compliance by merchants doing business in that state with the current PCI DSS and shielding compliant entities from liability. The Nevada law also allows merchants to avoid liability by other approved security standards. In 2010, Washington also incorporated the standard into state law. Unlike Nevada's law, entities are not required to be PCI DSS-compliant; however, compliant entities are shielded from liability in the event of a data breach.
Risk management to protect cardholder data:
In accordance with PCI DSS requirement 3, merchants and financial institutions are required to protect cardholder data with strong cryptography. Non-compliant solutions will not pass the audit. A typical risk management program has three steps: Identify all known risks and record them in a risk register; for example, hardware security modules (HSM) used in the cryptographic key management process could introduce risks if they are compromised physically or logically. HSMs create a root of trust in a system but, if an HSM is compromised, an entire system could be compromised.
Risk management to protect cardholder data:
Develop a risk-management program to analyze all identified risks. Included in this analysis should be a mix of qualitative and quantitative techniques to determine what risk treatment methods should be used to reduce risk; for example, an organization might analyze the risk of using a cloud HSM versus a physical device used on-site.
Risk management to protect cardholder data:
Treat the risks in response to the risk analysis, such as using different treatments to protect client information stored in a cloud HSM and ensuring physical and logical security in an onsite HSM. This could include implementing controls or obtaining insurance to maintain an acceptable level of risk.Continuous monitoring and review are part of the process of reducing PCI DSS cryptography risks. This includes maintenance schedules and predefined escalation and recovery routines when security weaknesses are discovered.
Controversy and criticism:
Visa and Mastercard impose fines for non-compliance. Stephen and Theodora "Cissy" McComb, owners of Cisero's Ristorante and Nightclub in Park City, Utah, were fined for a breach for which two forensics firms could not find evidence: The McCombs assert that the PCI system is less a system for securing customer card data than a system for raking in profits for the card companies via fines and penalties. Visa and MasterCard impose fines on merchants even when there is no fraud loss at all, simply because the fines are "profitable to them," the McCombs say.
Controversy and criticism:
Michael Jones, CIO of Michaels, testified before a U.S. Congressional subcommittee about the PCI DSS: [The PCI DSS requirements] are very expensive to implement, confusing to comply with, and ultimately subjective, both in their interpretation and in their enforcement. It is often stated that there are only twelve "Requirements" for PCI compliance. In fact there are over 220 sub-requirements; some of which can place an incredible burden on a retailer and many of which are subject to interpretation.
Controversy and criticism:
The PCI DSS may compel businesses pay more attention to IT security, even if minimum standards are not enough to eradicate security problems. Bruce Schneier spoke in favor of the standard: Regulation—SOX, HIPAA, GLBA, the credit-card industry's PCI, the various disclosure laws, the European Data Protection Act, whatever—has been the best stick the industry has found to beat companies over the head with. And it works. Regulation forces companies to take security more seriously, and sells more products and services.
Controversy and criticism:
PCI Council general manager Bob Russo responded to objections by the National Retail Federation: [PCI is a structured] blend ... [of] specificity and high-level concepts [that allows] stakeholders the opportunity and flexibility to work with Qualified Security Assessors (QSAs) to determine appropriate security controls within their environment that meet the intent of the PCI standards.
Controversy and criticism:
Visa chief enterprise risk officer Ellen Richey said in 2018, "No compromised entity has yet been found to be in compliance with PCI DSS at the time of a breach". However, a 2008 breach of Heartland Payment Systems (validated as PCI DSS-compliant) resulted in the compromising of one hundred million card numbers. Around that time, Hannaford Brothers and TJX Companies (also validated as PCI DSS-compliant) were similarly breached as a result of the allegedly-coordinated efforts of Albert Gonzalez and two unnamed Russian hackers.Assessments examine the compliance of merchants and service providers with the PCI DSS at a specific point in time, frequently using sampling to allow compliance to be demonstrated with representative systems and processes. It is the responsibility of the merchant and service provider to achieve, demonstrate, and maintain compliance throughout the annual validation-and-assessment cycle across all systems and processes. A breakdown in merchant and service-provider compliance with the written standard may have been responsible for the breaches; Hannaford Brothers received its PCI DSS compliance validation one day after it had been made aware of a two-month-long compromise of its internal systems.
Controversy and criticism:
Compliance validation is required only for level 1 to 3 merchants and may be optional for Level 4, depending on the card brand and acquirer. According to Visa's compliance validation details for merchants, level-4 merchant compliance-validation requirements ("Merchants processing less than 20,000 Visa e-commerce transactions annually and all other merchants processing up to 1 million Visa transactions annually") are set by the acquirer. Over 80 percent of payment-card compromises between 2005 and 2007 affected level-4 merchants, who handled 32 percent of all such transactions. | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**Venetian sauce**
Venetian sauce:
Venetian sauce (French: Sauce vénitienne) is a classical French herb sauce used to accompany fish. It consists of: a velouté and fish fumet base equal quantities of tarragon vinegar and white wine reduced with: chopped shallots and chervil White wine sauce Herb juiceAfter cooking, it is strained and finished with chopped chervil and tarragon. | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**Clinical associates**
Clinical associates:
Clinical Associates are a category of health professional found in South Africa. They assess patients, make diagnoses, prescribe treatment and perform minor surgery under the supervision of a physician.
Clinical associates:
Registration with the Medical and Dentists Board requires a Bachelor of Clinical Medical Practice degree - a three-year program offered at the Walter Sisulu University since January 2008 and now also offered at the University of Witwatersrand, University of Pretoria and the University of Limpopo (Medunsa Campus).Similar health workers are called clinical officers in other parts of Africa, physician assistants in the US and feldshers in parts of the former Soviet Union - all grouped under “paramedical practitioners” in the International Standard Classification of Occupations, 2008 revision. | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**Traffic-sign recognition**
Traffic-sign recognition:
Traffic-sign recognition (TSR) is a technology by which a vehicle is able to recognize the traffic signs put on the road e.g. "speed limit" or "children" or "turn ahead". This is part of the features collectively called ADAS. The technology is being developed by a variety of automotive suppliers. It uses image processing techniques to detect the traffic signs. The detection methods can be generally divided into color based, shape based and learning based methods.
History:
The Vienna Convention on Road Signs and Signals is a treaty signed in 1968 which has been able to standardize traffic signs across different countries. About 52 countries have signed this treaty, which includes 31 countries from Europe. The convention has broadly classified the road signs into seven categories designated with letters A to H. This standardization has been the main drive for helping the development of traffic-sign recognition systems that can be used globally.
History:
Traffic-sign recognition first appeared, in the form of speed limit sign recognition, in 2008 for the 2009 Vauxhall Insignia. Later in 2009 they appeared on the new BMW 7 Series, and the following year on the Mercedes-Benz S-Class. At that time, these systems only detected the round speed limit signs found all across Europe (e.g.).
History:
Second-generation systems can also detect overtaking restrictions. It was introduced in 2008 in the Opel Insignia, later followed by the Opel Astra and the Saab 9-5. This technology is also available on the 2011 Volkswagen Phaeton and, since 2012, in the Volvo S80, V70, XC70, XC60, S60, V60 and V40, as a technology called Road Sign Information. They are not able to recognize city limit signs, which in most European countries are associated with speed limits, as they are too similar to direction signs.
History:
Such systems are expected to be mandatory on new cars sold in the EU from May 2022 which should apply regulation 2021/1958 from 23 june 2021.
Implementation:
How does a traffic-sign recognition system work? Traffic signs can be analyzed using forward-facing cameras in many modern cars, vehicles and trucks. One of the basic use cases of a traffic-sign recognition system is for speed limits. Most of the GPS data would procure speed information, but additional speed limit traffic signs can also be used to extract information and display it in the dashboard of the car to alert the driver about the road sign. This is an advanced driver-assistance feature available in most high-end cars, mainly in European vehicles.
Implementation:
Modern traffic-sign recognition systems are being developed using convolutional neural networks, mainly driven by the requirements of autonomous vehicles and self-driving cars. In these scenarios, the detection system needs to identify a variety of traffic signs and not just speed limits. This is where the Vienna Convention on Road Signs and Signals comes to help. A convolutional neural network can be trained to take in these predefined traffic signs and 'learn' using Deep Learning techniques.
Implementation:
The neural net in turn uses Image Processing and Computer Vision to train the network with its potential outcomes. The trained neural net can then be used in real time to detect new traffic signs in real time. Self driving car companies including Waymo and Uber are generating and outsourcing traffic-sign data sets along with map and navigation companies like Tom Tom. Advanced computer vision and neural network techniques make this goal highly efficient and achievable in real time.
Implementation:
There are diverse algorithms for traffic-sign recognition. Common ones are those based on the shape of the sign board. Typical sign board shapes like hexagons, circles, and rectangles define different types of signs, which can be used for classification. Other major algorithms for character recognition includes Haar-like features, Freeman Chain code, AdaBoost detection and deep learning neural networks methods. Haar-like features can be used to create cascaded classifiers which can then help detect the sign board characters.
Implementation:
Deep learning can be incorporated into traffic-sign detection. Polygonal approximation of digital curves using Ramer–Douglas–Peucker algorithm can be used to detect the shape of the sign boards and methods like Support Vector Machines and Byte-MCT with an AdaBoost classifier has been used in one of the methods to detect traffic signs.Identification of speed limit signs also needs to take into account the units used in a particular area. For instance, a vehicle travelling from Northern Ireland to Ireland would need to be able to differentiate the km/h speed limit signage in Ireland from the mph speed limit signage still used in Northern Ireland, which is particularly important when traffic sign recognition is linked to Intelligent speed assistance systems. Geofencing and reference to online navigation databases can be used as a hint to the algorithm to identify which units are likely to be in use.
Usage:
Information might be relevant to be used in intelligent speed assistance.
Car makers and vehicles:
Some cars with such system are made by Audi, BMW, Citroën, Ford, Honda, Infiniti, Jaguar, Jeep, Land Rover, Lexus, Mercedes, Nissan, Opel, Peugeot, Porsche, Renault, Toyota, Volkswagen and Volvo.
For instance: Audi: Audi A8 BMW: BMW 7 Series, BMW 5 Series Gran Turismo, BMW 5 Series Mercedes: Mercedes-Benz E Class, Mercedes-Benz S Class Opel: Opel Insignia, Opel Corsa Saab 9-5 Volkswagen Phaeton Lexus: Lexus GS, Lexus LS, Lexus RX 2022+ | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**Recrudescence**
Recrudescence:
Recrudescence is the recurrence of an undesirable condition. In medicine, it is usually defined as the recurrence of symptoms after a period of remission or quiescence, in which sense it can sometimes be synonymous with relapse. In a narrower sense, it can also be such a recurrence with higher severity than before the remission. "Relapse" conventionally has a specific (albeit somewhat illogical) meaning when used in relation to malaria (see below).
Malaria:
In malaria, recurrence can take place due to recrudescence; or relapse; or re-infection (via mosquito transmission). Relapse means that a recurrence has been precipitated by a dormant stage in the liver called a "hypnozoite". Thus, relapse is applied only for those plasmodial species that have hypnozoites in the life cycle, such as Plasmodium vivax and P. ovale. On the other hand, recrudescence means that circulating, multiplying parasites are detected after having persisted in the bloodstream (or elsewhere) at undetectable levels for a period of time, as merozoites (as opposed to hypnozoites). This term is applied for Plasmodium species that are not associated with hypnozoite-mediated recurrences, such as P. falciparum, P. malariae, and P. knowlesi. Recrudescence is also used for malarial recurrence caused by drug-resistant strains of P. vivax and P. ovale where parasites remained in the bloodstream despite treatment.
Melioidosis:
In melioidosis, a recurrent infection can be due to re-infection and relapse. Re-infection is a recurrence of symptoms due to an infection with a new strain of Burkholderia pseudomallei following the eradication therapy of melioidosis. Meanwhile, relapse are those who presented with melioidosis symptoms due to failure to clear the infection in the bloodstream after completion of eradication therapy. On the other hand, recrudescence is the recurrence of melioidosis symptoms during the eradication therapy.
Bovine viral diarrhoea:
The bovine viral diarrhoea virus (bovine virus diarrhea) is said to be recrudescent for some time after clinical signs have abated, because antibodies plateau c. weeks 10–12, and are not lifelong, auto infection may potentially occur in the acutely infected non-pregnant animal.
Others:
Other diseases that may recur following a short or long period of quiescence include shingles (after chicken pox), oral herpes and genital herpes, and Brill–Zinsser disease (after epidemic typhus). | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**Teen idol**
Teen idol:
A teen idol is a celebrity with a large teenage fan base. Teen idols are generally young but are not necessarily teenagers. An idol's popularity may be limited to teens, or may extend to all age groups.
By region:
Asia East Asia possesses a robust fan culture centered around idols, one that spans both genders and generates broad appeal. East Asian idol culture, which first began in Japan in the 1960s, would spread to neighboring countries in later decades: in South Korea and Taiwan, for example, it took root in the 1990s, and in China the 2010s. Idols are also not limited to singing, and may take part in more explicitly image-focused venues such as pin-up photography (gravure idols) and pornography (AV idols).
By region:
There are many different idols and idol groups spread across many countries. In Japan, there are pop stars Ayumi Hamasaki and Namie Amuro as well as Kana Nishino and music groups such as Momoiro Clover Z, Morning Musume, AKB48, and Perfume and Johnny & Associates boy bands Arashi, NEWS, KAT-TUN, and Hey! Say! JUMP among others. In Taiwan, there are pop icons such as Jay Chou, Jolin Tsai, music groups Mayday, F4, and S.H.E. In South Korea, notable K-pop personalities include singers BoA and Rain and groups BTS, Blackpink, Exo, TVXQ, 2PM, 2AM, Beast, Shinee, Super Junior, 2NE1, Big Bang, Wonder Girls, T-ara, Kara and Girls' Generation. In Vietnam, there are the singers WanBi Tuấn Anh, Sơn Tùng M-TP, Đông Nhi, Bảo Thy and Tóc Tiên.
By region:
Europe European teen idols include German popstar Bill Kaulitz of the pop-rock band Tokio Hotel and the members of the Anglo-Irish pop boy band One Direction, and Girls Aloud, another Anglo-Irish band. In Spain, La Oreja de Van Gogh, Miguel Bosé, Mecano, and Hombres G all enjoyed teen-idol status. In the Balkans, the late Macedonian singer Toše Proeski was considered a teen idol.
By region:
Latin America In Latin America, idols ranges from Mexican pop stars Timbiriche, Lynda Thomas, Magneto, Puerto Rican born Mexican Luis Miguel, Colombian Shakira and the popular Puerto Rican boy band Menudo in the 1980s and 1990s, and Paty Cantú, Anahí, Belinda, and RBD in the 2000s and 2010s. Besides, former Menudo member Ricky Martin, their chief rivals Los Chicos and former member Chayanne, Venezuelan actor and singer Guillermo Davila and more, to Argentina, where telenovela, Chiquititas, ushered in a new era of teen-idols for that country, including actors Benjamin Rojas, Felipe Colombo, Luisana Lopilato, and Camila Bordonaba, who went on to form teen band Erreway, precursors to Mexican band RBD.
By region:
North America Often teen idols are actors or musicians. Some teen idols began their careers as child actors, such as Britney Spears, Hilary Duff, Raven-Symoné and Miley Cyrus. There were teen idols before there were teen magazines, but idols have always been a permanent feature in magazines such as Seventeen, 16, Tiger Beat and Right On! in the United States, and in similar magazines elsewhere. With the advent of television, teen idols were also promoted through programs such as American Bandstand, The Ed Sullivan Show, Soul Train. Today's teen idols have spawned an entire industry of gossip magazines, television shows, YouTube, social media, and whole television channels such as E!.
By era:
Early teen idols The first known person to have been treated as a teen idol was Franz Liszt, the Hungarian pianist who, in the 1840s, drew such a following among teen girls that the term "Lisztomania" soon came to describe the phenomenon. The kind of idolizing following Liszt drew in Europe would not be followed for several decades. American-born Roger Wolfe Kahn became, arguably, America's first modern-day teen idol, when, in 1924 at the age of sixteen he launched his first jazz band. Throughout his teens, he became dubbed the 'Millionaire Maestro.' Geraldine Farrar, American opera singer, had a large following of young women nicknamed "Gerry-flappers" in the early 20th century. Rudy Vallée, who became a major success in 1929 with hits like "Honey" and "Deep Night", may have been the first American popular singer to have been idolised by hundreds of teen-aged girls at sold-out concerts. He was also possibly the first popular singer to have a star vehicle created for him: The Vagabond Lover.
By era:
Frank Sinatra, whose early career in the 1940s is often linked to his appeal to bobby soxers, who got that name because they were forced to dance in their bobby socks so that their shoes would not damage the dance floor, is also regarded as having been amongst the first teen idols.
By era:
1950s–1960s Although he had only three major movie roles, James Dean earned two Oscar nominations. He also had the image of a rebellious youth, something that was popular among girls and young women. His performance in Rebel Without A Cause (1955) and his untimely death in a road collision in 1955 cemented his status as an icon. Contemporary teenagers still wear white T-shirts and jeans in his style.Selected by Walt Disney in 1955 for his new show The Mickey Mouse Club, Annette Funicello became popular among viewers by the end of the first season. Elvis Presley made his debut in the mid-1950s and became a sensation. Deemed too dangerous to be filmed except from the waist up because of his sexually suggestive dance moves, he became popular among teenagers. The success of young rock stars like Presley, film stars like Marlon Brando, Paul Newman, James Dean, Tab Hunter, and Sal Mineo in the 1950s, as well as the wider emergence of youth subcultures, led promoters to the deliberate creation of teen idols such as singers Frankie Avalon, Frankie Valli, Frankie Lymon, Fabian Forte, Bobby Rydell and Connie Stevens. Even crooners like Frank Sinatra were still considered idols and rather handsome. Actors Edd Byrnes and Troy Donahue and other artists deliberately cultivated a (safer) idol image, like Canadian musician Paul Anka.
By era:
Anka initially modelled himself on a particular generic type, the teen idol [who] carried on the process ... of changing the image of male youth ... from wild to mild, by providing a cleaner, more wholesome image of masculinity than that of the previous era's rebellious rockabilly heroes [and (working-class) so-called juvenile delinquents, like those in West Side Story]....
By era:
Post-war teens were able to buy relatively inexpensive phonographs — including portable models that could be carried to friends' houses — and the new 45-rpm singles. Rock music played on 45s became the soundtrack to the 1960s as people bought what they heard on the radio. The great majority of the music being marketed to 1950s teens was being written by adults, but 1960s teens were increasingly appreciating and emulating artists closer to their own age, to teen fashion, and to lyrics which addressed their own concerns. Their parents worried about their attraction to artists (and DJs) who were edgy and rebellious. Faces on magazines fed fans; fans buy records, see films, watch TV and buy fashions.
By era:
Marketing of the teen idol generally focuses on the image.... The teen idol is structured to appeal to the pre-teen and young teen female pop audience member and children in general.... [They] are commodified in forms and images that are relatively non-threatening to this young audience and to the ancillary market of parents... The teen idol never appears to be autonomous and therefore never appears to be threatening as an adult; he remains, as long as he is popular, perpetually childlike and dependent.
By era:
Some marketers turned to film and TV for fresh, 'safe' faces. Tommy Sands's debut in a television film about the phenomenon, The Idol, made a teen idol out of Sands himself. Ricky Nelson, a performer of rockabilly music, also became a teen idol through his parents' television series, The Adventures of Ozzie and Harriet. With many parents disapproving of Elvis Presley, Nelson became a safe alternative. However, he found himself outclassed by the Beatles when they arrived in the U.S. in 1964.The Beatles soon became the most successful and influential band in modern musical history, staying at the top of Billboard charts for a grand total of 58 weeks between 1964 and 1970. Adolescent hysteria was so loud that the band had trouble performing at concerts. The level of stardom they achieved in the U.S.—dubbed Beatlemania—was never before seen in that country, not even during the heyday of Elvis Presley.Some young TV stars were being hustled into studios to make recordings; for example, ex-Mousketeer Annette Funicello became one of the first big female idols as well as the Lennon Sisters whom had cut out dolls and were always on the covers of the gossip magazines; another, Johnny Crawford of The Rifleman, had five Top-40 hits. In 1963, Luke Halpin made a big splash as a teen idol in the television program Flipper. After Bye Bye Birdie was released in 1963, Bobby Rydell became an instant teen idol.
By era:
In the 1960s as situation comedies and dramas on television using child actors became more popular, actors Paul Petersen, Patty Petersen, and Shelley Fabares from The Donna Reed Show, Dwayne Hickman from The Many Loves of Dobie Gillis, Sally Field of Gidget, Jon Provost of Lassie, Jay North from Dennis the Menace, and Keith and Kevin Schultz known as the "Schultz Twins" on The Monroes all became younger preteen idols and grew into being teen idols.
By era:
Herman's Hermits, the Rolling Stones, and the Beach Boys were teen idols, especially during the earlier part of their careers, although they quickly grew out of that status. The Rolling Stones did it through a more rebellious image, the Beatles did it through their more developed (or "grown up") music. Similarly, Neil Sedaka had two distinct eras of his career, with about a decade in between: one as a teen idol in the 1960s, and a later career in adult contemporary music. Roy Orbison was known for his songs "Oh, Pretty Woman," "Only the Lonely," and "Crying." From the family band the Cowsills, Susan Cowsill, John Cowsill and Barry Cowsill became teen idols. Many of the teen idols of the era were the sons of older, established stars; Dino, Desi & Billy were active as teen idols during the mid-sixties. The group included Dean Paul Martin (son of singer Dean Martin), and Billy Hinsche (a mutual friend whose parents were not famous). Gary Lewis, son of comedian Jerry Lewis, fronted the Playboys during this era.
By era:
All of the Monkees became instant teen idols in the late 1960s after their TV show became an overnight success, especially for Micky Dolenz and Davy Jones. The British-born Monkee Davy Jones was regularly featured in teen fan magazines. In 2008, Yahoo Music named Jones the number one teen idol of all time, and in 2009 he was ranked second in a list compiled by Fox News.Teen fan magazine TeenSet began publishing in 1964, focusing on youthful bands and musicians. Tiger Beat magazine began competing for the same audience in 1965.
By era:
1970s After Davy Jones came Bobby Sherman and David Cassidy, who held the title of Teen Idols from the late 1960s until the mid-1970s. Both Sherman and Cassidy were actors on television and chart topping musicians in the pop-rock category at the time; with David Cassidy in particular enjoying immense international fame and success. Sherman was on hit TV shows Shindig! and Here Come the Brides among many others. Musical series such as Cassidy's The Partridge Family, the animated series The Archie Show, and (to a lesser extent) The Brady Bunch integrated television and teen-pop music to significant success during this time frame. The Brady Bunch's Barry Williams and Christopher Knight, as was tennis pro/actor Vincent Van Patten all were constantly in the fan magazines at the time. Popular actors such as John Moulder Brown, Leonard Whiting, Ray Lovelock (Raymond Lovelock), Leif Garrett, Mark Hamill, Mark Lester, Jan-Michael Vincent and Jack Wild were the talk of the teenagers in the 1970s as well. Musical group the Hudson Brothers were on many teen magazine covers for a number of years as teen idols. They had two shows on TV during the 1970s and recorded many albums.
By era:
One of the features of many teen idols is that their fans (and, in some cases, the musicians themselves) tended to develop a hate for the music once they became adults, and it is not much listened to by adults, except for nostalgia: the legacy of bubblegum pop. Teen idol performers in this category would include Shaun Cassidy, Leif Garrett, the Osmond Brothers (particularly Donny Osmond and their teen idol sister Marie Osmond), Andy Gibb, Tony DeFranco of the Canadian band the DeFranco Family, and the Bay City Rollers (UK). Even modern classic hits and oldies outlets, which cover this time period, rarely play cuts from the teen idols of the era. A notable exception is Michael Jackson of the Jackson Five, who began his career as a teen idol along with his brothers, but whose individual career eventually evolved far beyond the limitations of that description and into superstardom.
By era:
The Jackson Five were the first African-American music group to become national teen idols, appearing along with famous white idols in magazines such as 16 and Tiger Beat. In addition, the charismatic appeal, showmanship and flurry of fans towards lead Michael Jackson made him a teen idol and heartthrob amongst teens; his success as a soloist continued into the 1980s.
By era:
1980s In 1985, actress Alyssa Milano from Who's the Boss? became a major teen idol and was dubbed "The Teen Queen of the 1980s". In the mid-1980s there was a group of young actors called the Brat Pack; the whole group collectively and separately became teen idols. They were Emilio Estevez, Anthony Michael Hall, Rob Lowe, Andrew McCarthy, Demi Moore, Judd Nelson, Molly Ringwald, and Ally Sheedy. They starred in many coming of age films together in some fashion and became very popular without being musicians. Molly Ringwald entered the limelight with the films Sixteen Candles and The Breakfast Club.Actors Corey Feldman and Corey Haim also became teen idols during the later part of the 1980s with films The Goonies and together The Lost Boys, Dream a Little Dream and License to Drive among other films. They were dubbed "the two Coreys". Before Corey Haim's death in 2010, they did a reality TV show for two seasons (2007–08) on A&E named The Two Coreys after their 1980s moniker.
By era:
Actor River Phoenix during his teen years became a teen idol during the later part of the 1980s, as did Christian Slater.
Australian singer-actor Rick Springfield was regarded as the teen idol in the 1980s with such hits as "Jessie's Girl" and "Don't Talk to Strangers". The Grammy Award-winning musician Springfield was known for playing Dr. Noah Drake on the daytime drama General Hospital. He originated the character from 1981 to 1983. He left acting after his music career took off.
During this decade, Puerto Rican boy band Menudo, caused a sensation in Latin America, nicknamed Menudomania that became compared to the Beatles' Beatlemania.
At the end of the 1980s, actor Kirk Cameron became a major teen idol. Cameron was best known for his role as Mike Seaver on the television situation comedy Growing Pains from 1985 to 1992. Also Scott Baio and Willie Aames of Charles in Charge fame found themselves regulars in teen magazines.
By era:
In popular music, the late 1980s was the boom of teenagers dominating the music charts. Debbie Gibson became the youngest person to write, perform and produce a number-one single, "Foolish Beat", and also had many hits from her first two albums. Tiffany, another teen icon, became a pop sensation at 15 years old thanks to an aggressive marketing strategy. She promoted her debut album in shopping malls of the US. She is also the youngest person to have a debut album hit number one and have multiple number one singles from that album ("I Think We're Alone Now" and "Could've Been"). Having become a household name, she had then-unknown band New Kids on the Block as an opening act for her shows. However, the sudden popularity of the New Kids caused their roles to be reversed. Gibson and Tiffany's careers had stalled by the early 1990s; so had NKOTB by the mid-nineties. The other boy band from Boston, New Edition, was popular with the teen set by the end of the 1980s.
By era:
One of the most popular female singers of the 1980s, with teen idol status was Madonna, especially among youth female audience which was later named Madonna wannabes. With songs "Like a Prayer", "Who's That Girl" and "Like a Virgin" in the '80s top lists throughout the decade, she became a teen idol through her acclaimed music, groundbreaking videos, celebrity tabloid image, feminist punk spirit, public acceptance of the marginalised LGBTQ+ community, unique fashion at the time and her very loyal fanbase.
By era:
1990s The manufacturing of teen idols has been marketed more aggressively and with greater sophistication since the 1980s. Many of the major teen idols in the 1990s were bands and musical acts. The rise of MTV in the 1980s and the success of the boy bands and girl groups during the 1990s and 2000s continued to fuel the phenomenon. Besides a combination of good, clean-cut looks and a ubiquitous marketing campaign, such bands typically include a variety of personality types (e.g. "the shy one", "the smart one", etc.) These idols were often found on the covers and pages of teen magazines during the 1990s as teen idols as well. Classic examples of boy bands include Menudo, New Kids on the Block, Take That, Backstreet Boys, and NSYNC, all becoming the best-selling pop groups of the decade. Hanson was initially marketed as such a band, but eventually outgrew this label to become a successful indie band. Christina Aguilera, Jennifer Lopez, Mandy Moore, Jessica Simpson, and Britney Spears, along with female bands such as the Spice Girls, TLC, and Destiny's Child, also became very popular at the end of the decade. Even though the Spice Girls split in 2000, they remain fairly popular in England.During this decade, the Latin artist Shakira was described as a "teen idol", her songs reached number 1 on Latin radio, her videos were among the most viewed, while her hair and clothing style was emulated by girls and young women. from the continent identifying with their songs, this was called "Shakiramía" or "Shakira Fever"The Backstreet Boys' popularity grew in 1997 with "Everybody (Backstreet's Back)," a song produced by Max Martin. Opting against joining a girl band, Britney Spears released the music video "...Baby One More Time" in 1998 on MTV, which pushed her into the public consciousness. Her first album of the same name made its debut at the top of Billboard's charts.After the movie Clueless (1995), Alicia Silverstone became a teen idol. The 1997 film Titanic made Leonardo DiCaprio a teen idol; during "Leo-Mania" his face appeared on many teen magazines. Fraternal twin sisters and actresses Ashley Olsen and Mary-Kate Olsen were major tween idols and as they grew up they later became teen idols during the 1990s.
By era:
2000s The 2000s would be a decade of transition due to increasing amount of media platforms coming from TV and the internet, though Hollywood would still be a spring board for many names in the early years of the decade. Actors such as Josh Hartnett, Heath Ledger and Ashton Kutcher would dominate the teen idol scene for the early 2000s. Hartnett become the most prominent face of the young Hollywood actors entering the 2000s. He appeared on dozens of major magazine covers and was the subject of a Vanity Fair cover story remarking on his meteoric rise to fame. The intense attention he received during this time period caused him to turn down high-profile roles, including a reported $100 million offer to play Superman, before temporarily leaving Hollywood.The Walt Disney Company and its numerous outlets (e.g. Disney Channel, Radio Disney and Walt Disney Pictures) were the first to successfully develop a new generation of teen idols in this period, starting with the careers of actresses and singers Hilary Duff and Lindsay Lohan, initially targeting youth and female teen audiences. While still teenagers, Duff became famous for her starring titular character in the Disney Channel teen sitcom Lizzie McGuire and her multi-Platinum second studio album Metamorphosis (2003), with which she became one of the youngest artists to reach the top of the Billboard 200, and Lohan became famous for her starring roles in many successful teen movies, including Freaky Friday (2003), Confessions of a Teenage Drama Queen (2004), Mean Girls (2004) and Herbie: Fully Loaded (2005), and her debut studio album Speak (2004). The success of this marketing led to further development of the genre, including new teen idols such as Raven-Symoné, Dylan and Cole Sprouse, Zac Efron, Aly & AJ, Jesse McCartney, Vanessa Hudgens, Ashley Tisdale, Corbin Bleu, Miley Cyrus, Selena Gomez, Demi Lovato and the Jonas Brothers. Disney has also used another one of its own TV channels, Freeform, to develop shows and stars popular among teen girls. Mean Girls, a well-known comedy written by Tina Fey, also saw the performances of Rachel McAdams and Amanda Seyfried (in her first role).Raven-Symoné gained popularity as a child actor for her roles on The Cosby Show (1989-1992) and Hangin' with Mr Cooper (1993-1997) but became a household name from being the titular character on the extremely popular and successful Disney Channel Show That's So Raven (2003-2007) as well as being a part of The Cheetah Girls and the films (2003-2006). She also had a supporting role in The Princess Diaries 2: Royal Engagement (2004).
By era:
Miley Cyrus claimed her fame by playing a fictionalized version of herself on the television show Hannah Montana (2006-2011). Her 2009 singles "The Climb" and "Party in the U.S.A" were both hits. However, as she began metamorphosizing into something more mature, her popularity fell as parents considered her new materials inappropriate for their children.Selena Gomez made her debut by starring in the Disney situational comedy Wizards of Waverly Place (2007-2012) and released her first album Kiss & Tell in 2009. She became an icon for adolescent girls and women, yet details of her personal life put her under public scrutiny.
By era:
ViacomCBS-owned Nickelodeon, a competitor to Disney Channel, has also developed its own slate of stars for its television shows, including Drake Bell, Josh Peck, Emma Roberts, Miranda Cosgrove, Jennette McCurdy, Nathan Kress, Jamie Lynn Spears (sister of Britney Spears), Ariana Grande, Victoria Justice, Elizabeth Gillies, and groups the Naked Brothers Band and Big Time Rush, many of whom have not only starred in TV shows, but recorded songs as well. Many of the modern-day teen idols are females marketed as "role models" to teen and tween girls, a departure from the traditional role of the male teen idol marketed as the idolized teen "heartthrob". Actress Mischa Barton became a teen idol through her role on The O.C., with Entertainment Weekly naming her character Marissa Cooper “It Girl" of 2003.
By era:
In 2002, Canadian singer Avril Lavigne dominated the music scene and eventually became a worldwide teen idol. Listed at #4 on Yahoo!'s Top 25 Teen Idols of all-time.During the popularity of her sister Jessica Simpson's MTV reality television series Newlyweds: Nick and Jessica, 7th Heaven actress Ashlee Simpson developed a music career through her own MTV spin-off reality series The Ashlee Simpson Show in 2004, and soon became a teen idol.
By era:
American musician Taylor Swift entered the scene at age 16 by co-writing the song "Tim McGraw" with Liz Rose in 2005, after which she became a well-known and successful artist as well as a teen idol.Before reaching the age of 20, Ariana Grande had already been popular among secondary schoolchildren by starring in the teen comedy show Victorious (2010-2013). She left acting for singing, and although her singing career got off to a rocky start, she did capture the attention of producer and songwriter Max Martin, who had worked with many successful artists before.Teen idols were also popular in the R&B and Hip-Hop realm throughout this decade, including Chris Brown, JoJo, Bow Wow, 3LW, Ciara, Mario, B2K, and Rihanna, among others.
By era:
In the late 2000s, bands like Lillix, KSM, Everlife, and Clique Girlz became teen pop idols and have a teenage fanbase.
Discovered on YouTube by media entrepreneur Scooter Braun at the age of 13, Justin Bieber was ushered into fame with his 2009 album My World.
By era:
2010s In Japan, more and more Japanese idol groups have appeared. In Japanese culture, persons called "idols" are media personalities in their teens and early twenties who are considered particularly attractive or cute and who will, for a period ranging from several months to a few years, regularly appear in the mass media, e.g. as singers for pop groups, bit-part actors, TV personalities, models in photo spreads published in magazines, advertisements, etc. One of the most successful groups is Momoiro Clover Z. Their performances incorporate elements of ballet, gymnastics, and action movies. During 2014, about 486,000 people attended their live concerts, which was the highest record of all female musicians in Japan. Momoiro Clover Z has been ranked as one of the most popular female idol groups from 2013 to 2017.In the late 2010s, many young actors developed large followings amongst teenagers and millennials after portraying famous contemporary literary characters. The most notable among these were Ansel Elgort (Augustus Waters), Timothée Chalamet (Elio Perlman), and Nick Robinson (Simon Spier). These actors were referred to by the media and general public as "White Boys of the Month", with the term becoming a popular meme since. Noah Centineo became popular among teenagers and young adults following the release of To All the Boys I've Loved Before, having amassed over 15 million Instagram followers within eight weeks of the film's release; he was dubbed an "internet boyfriend" by the media.Although the future members of the boy band One Direction did not do well on the third season of X Factor U.K., guest judge Nicole Scherzinger suggested that they form a group together. The result was much fame and fortune for the band, who burst onto the scene in 2012. The group went on indefinite hiatus in 2016, and since 2017 its members have been pursuing solo projects.
By era:
Similarly, in 2016 the Cuban-born American singer Camila Cabello left the girl group Fifth Harmony, which went on indefinite hiatus in 2018, in order to pursue a solo career. She makes use of her Latin American heritage in her rhythms. At age 18, American musician Billie Eilish won four Grammy Awards in 2020, and was commissioned to perform the theme song for the James Bond movie No Time to Die (2021). The song topped the charts in February 2020. She wrote it with her brother, Finneas, becoming the youngest artist to do so. She has tens of millions of followers on social media, especially among Generation Z, and is well known for her lyrics concerning depression and anxiety. Millie Bobby Brown rose to fame from her role as Eleven in the Netflix series Stranger Things. Her co-stars Finn Wolfhard, Gaten Matarazzo, Caleb McLaughlin, Noah Schnapp, and Sadie Sink have also achieved fame from their roles in the series.
By era:
2020s American artist Olivia Rodrigo had previously worked as a child actress on the Disney comedy series Bizaardvark (2016–19) and starred in the first three seasons of High School Musical: The Musical: The Series (2019–present). In January 2021, she released her debut single, "Drivers License", which went on to become one of the most streamed songs on Spotify at the time and spent eight weeks on top of the Billboard Hot 100 chart. She sings with profanities in an emotionally charged manner of the struggles of an adolescent and commands a large following on social media networks, including TikTok, where she has many teen-aged supporters. She cites Taylor Swift and Lorde as her influences. Some sources consider Rodrigo to be a representative of Generation Z.Italian rock band Måneskin was ushered into worldwide attention after winning the Eurovision Song Contest 2021, with their winning track "Zitti e buoni" as well as "I Wanna Be Your Slave" and their cover of The Four Seasons' "Beggin'" reaching the top 10 on the Billboard Global Excl. U.S. chart, supported by a growing following on TikTok and other social media platforms. Prior to their Eurovision win, the band finished as runner-up in the eleventh season of the Italian X Factor in 2017. Måneskin are credited as one of the first rock bands to heavily appeal to Generation Z.
Impact and influence:
In the West, the Beatles, Bob Dylan, and the Rolling Stones were extremely popular among the Baby Boomers. Parents, by contrast, saw their influence greatly diminished. In the United Kingdom, for instance, a combination of the Lady Chatterley trial (1959) and the first long-play of the Beatles, Please Please Me (1963) triggered a change public perception of human mating, a cause subsequently taken up by young people seeking sexual liberation.During the 1960s and 1970s, the music industry made a fortune selling rock records to people between the ages of fourteen and twenty-five. This era was home to many youthful stars—people like Brian Jones of the Rolling Stones or Jimi Hendrix—who had lifestyles that all but guaranteed early deaths. The death of a (former) teen idol can have a serious impact on fans, leading to outbursts of emotions. This was certainly the case when people like Davy Jones or Michael Jackson died. Moreover, even as their fans age, the audience of idols does not necessarily shrink, as the fans who became parents can introduce their children to their music. People tend to be nostalgic about music from their youth. In the twenty-first century, (former) teen idols can continue to be highly successful years after they made their debut as can be seen from the number of streams, digital downloads, CDs, cassettes, and vinyl records shipped.The charm and charisma manifested by American actor James Dean onscreen proved strongly appealing to the audience, and his persona of youthful rebellion provided a template for succeeding generations of youth to model themselves on. Various artists, including Leonardo DiCaprio, Buddy Holly, and David Bowie, cited Dean as an influence. American singer-songwriter Taylor Swift referenced him in "Style" (2014). Meanwhile, wearing white T-shirts and jeans remains iconic among young people today.
Impact and influence:
The K-pop band Girls' Generation has generally been considered as a cultural icon of not just South Korea, but also a part of the Korean Wave, the rising popularity of Korean culture on the international stage. As of 2019, another K-pop band, BTS, was reportedly worth more than US$4.65 billion, or 0.3 percent of the GDP of their home country. They attracted one in every 13 foreign visitors to South Korea and were cited as one of the key acts in boosting global music sales to US$19 billion in 2018. Data from the International Federation of the Phonographic Industry (IFPI) shows that BTS became the best-selling artists of 2020 worldwide, ahead of Taylor Swift, Drake, the Weeknd, and Billie Eilish.A 2023 report by the Federal Reserve estimated that Taylor Swift's Eras Tour was responsible for $4.6 billion of consumer spending in the United States alone; local economies were significantly boosted by her presence. Besides the Fed, the governments of Cincinnati, Ohio, and Chicago, Illinois, have credited Swift with boosting their local tourism and hospitality industries. | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**Triacylglycerol—sterol O-acyltransferase**
Triacylglycerol—sterol O-acyltransferase:
In enzymology, a triacylglycerol---sterol O-acyltransferase (EC 2.3.1.77) is an enzyme that catalyzes the chemical reaction triacylglycerol + a 3beta-hydroxysterol ⇌ diacylglycerol + a 3beta-hydroxysterol esterThus, the two substrates of this enzyme are triacylglycerol and 3beta-hydroxysterol, whereas its two products are diacylglycerol and 3beta-hydroxysterol ester.
This enzyme belongs to the family of transferases, specifically those acyltransferases transferring groups other than aminoacyl groups. The systematic name of this enzyme class is triacylglycerol:3beta-hydroxysterol O-acyltransferase. This enzyme is also called triacylglycerol:sterol acyltransferase. | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**Egg of Columbus (mechanical puzzle)**
Egg of Columbus (mechanical puzzle):
The names Egg of Columbus and Columbus Egg have been used for several mechanical toys and puzzles inspired on the legend of Columbus balancing an egg on its end to drive a point. Typically, these puzzles are egg-shaped objects with internal mechanisms that make the egg stand up, once the user discovers the secret.
Mechanisms typically used in such toys include moving weights, mercury flowing in sealed tubes or compartments, and steel balls rolling on grooves and pits.
History:
A Columbus Egg puzzle using a rolling ball was described in an 1893 book. The Montgomery Ward catalog of 1894 includes a "Columbus Egg" toy.There are at least 18 United States patents for such devices, starting from 1891.The German company Pussycat sells a Columbus Egg that can be balanced by holding it upright for 25 seconds, then quickly inverting it. The egg will then stand on its pointed end for 15 seconds, then topple on its side. | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**Informedia Digital Library**
Informedia Digital Library:
The Informedia Digital Library is an ongoing research program at Carnegie Mellon University to build search engines and information visualization technology for many types of media.The program has carried out research on spoken document retrieval, video information retrieval, video segmentation, face recognition, and cross-language information retrieval.
The Lycos search engine was an early product of the Informedia Digital Library Project.
The project is led by Howard Wactlar. Researchers on the project have included: Michael Mauldin, Alex Hauptmann, Michael Christel, Michael Witbrock, Raj Reddy, Takeo Kanade and Scott Stevens. | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**Oligotyping (sequencing)**
Oligotyping (sequencing):
Oligotyping is the process of correcting DNA sequence measured during the process of DNA sequencing based on frequency data of related sequences across related samples.
History:
DNA sequences were originally read from sequencing gels by eye. With the advent of computerized base callers, humans no longer 'called' the bases and instead 'corrected' the called bases. The bases were called by the software using the relative intensity of each putative basepair signal and the local spacing of the signals.
With the advent of high throughput sequencing, the volume of sequence to be corrected exceeded human capacity for sequence correction.
Use:
Multiple applications require single-base pair accuracy across populations of closely related sequences. An example is amplicon sequencing to assess the relative contribution of DNA from diverse organisms to a sample.
Use:
The requirement for single basepair accuracy led to the development of methods which drew on frequency data distributed across several samples to identify variant sequences which shared the same frequency profile and were thus likely errors from the same original sequence. The ability to use higher-order statistics to correct sequences is an important element in decreasing the burden of error in DNA sequence datasets. | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**Monkey Brains**
Monkey Brains:
Monkey Brains is a 2001 puzzle video game developed by Yobro productions for PC. The game follows injured scientist Dr. Simius who attempts to stop the evil Dr. Kreep from using mind-control technology.
Gameplay:
Levels are presented from a side-scrolling view, with Dr. Simius controlling a group of monkeys who must perform tasks like pulling levers and pressing buttons while evading traps and enemies in order to progress to the next level. The game's enemies and obstacles present an action component for the game, as a player may have to navigate a monkey though a crushing machine or past flying mines. Only one monkey can be controlled at a time. All hazards in the game are non-lethal, though they will reduce the player's health bar; the game is over when the health bar is depleted. Health can be replenished by collecting fruit.
Reception:
While describing it as a bizarre experience, IGN spoke favourably of the game's demo, stating "you really have to play it to believe it, but it's a bunch of nutty fun. "Charles Herold from The New York Times stated that while it was not a "game for the ages, Monkey Brains is an entertaining time waster that can make the hours roll by like minutes." Trey Walker from GameSpot gave the game 5.9 out of 10, concluding: "Overall, Monkey Brains is a game that's suitable for those who like side scrollers but are looking for more puzzles and less action. The graphics and sound are adequate, many of the levels and puzzles can be entertaining, and the game mechanics add a bit of a twist." | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**Purine riboswitch**
Purine riboswitch:
A purine riboswitch is a sequence of ribonucleotides in certain messenger RNA (mRNA) that selectively binds to purine ligands via a natural aptamer domain. This binding causes a conformational change in the mRNA that can affect translation by revealing an expression platform for a downstream gene, or by forming a translation-terminating stem-loop. The ultimate effects of such translational regulation often take action to manage an abundance of the instigating purine, and might produce proteins that facilitate purine metabolism or purine membrane uptake.
Binding properties:
Purine riboswitches bind to their purine ligands via interactions at a three-way junction formed by junctional helix P1 and hairpin helices P2 and P3. Associations that a purine makes when it is within this binding pocket stabilize the three-way junction, and support the ligand-bound conformation of the mRNA molecule. The purine riboswitch can become saturated at concentrations as low as 5 nM, which reflects the need for gene expression to respond quickly and dynamically to changes in purine concentration.Despite the relative similarity of the purine-binding aptamer domain across different purine riboswitches, one binding pocket can still discriminate for a single type of purine ligand with high selectivity. Critical to this sensitivity is a single difference in the secondary structure of ribonucleotides: in position 74 of the aptamer domain, it has been found that conversion of a cytosine to a uracil changes an aptamer from being guanine sensitive to being adenine sensitive, and vice versa. Such a conversion is owed to the ability of a nucleotide in position 74 to Watson-Crick base pair with the ligand in the binding pocket, and cytosine and uracil's respective ability to preferentially hydrogen-bond with guanine or adenine.
Adenine Riboswitch:
The Adenine Riboswitch selectively recognizes adenine, and contains a uracil ribonucleotide in position 74 of the adenine-binding aptamer domain. Some of the more frequently researched instances of this riboswitch are detailed below.
Adenine Riboswitch:
add The add gene encodes adenosine deaminase, and the adenine riboswitch that is upstream exposes the gene's start codon and the Shine-Dalgarno sequence when adenine is present in the binding pocket. This behavior facilitates adenosine deaminase translation, and in this way, the add adenosine riboswitch contributes to a metabolic negative feedback mechanism that regulates the amount of adenine present in the system.
Adenine Riboswitch:
Ligand-binding conformational changes The add adenine riboswitch has shown three distinct stable conformations in the presence of adenine. When unbound to adenine, the mRNA sequence converts between two different non-translatable conformations, one of which is able to accept adenine into the binding pocket and conform to the adenine-bound mRNA shape. This three-stage mechanism is quite distinct from the standard two-stage explanation of riboswitch action, which assumes a single ligand-bound state and a single ligand-unbound state. This mechanistic uniqueness of the add adenine riboswitch may serve as a benefit for organisms like Vibrio vulnificus, whose varied habitats require a particularly nuanced metabolic sensitivity to a wide variety of environmental conditions.
Adenine Riboswitch:
The figure at right shows a space-fill drawing of an unbound state (left, from PDB file 5e54) and the state with adenine bound (right, from PDB file 5swe). The part colored pink forms a complete A-form RNA helix in the bound form, and the yellow part shifts position.
Adenine Riboswitch:
Magnesium and temperature dependence At higher temperatures, conversion between different conformations of unbound add adenine riboswitch favors the form that is able to accept adenine into its binding pocket. Higher temperatures also favor the conversion of this unbound riboswitch to the adenine-bound, start-sequence-exposed conformation. The concentration of Magnesium ion has an influence on only the latter of these conformation changes, and favors the binding of adenine to the riboswitch. The combination of these effects facilitates a more controlled translation of the add gene at lower temperatures: taking a portion of the unbound riboswitch and rendering it unable to bind adenine increases the sensitivity of the remaining portion to magnesium.
Adenine Riboswitch:
pbuE The pbuE gene encodes a purine base efflux pump. Binding of adenine to the pbuE adenine riboswitch disrupts the structure of a terminator stem that had been blocking access to the gene expression platform. In this way, an abundance of adenine can instigate the process of adenine's efflux from a cell.
Ligand-binding conformational changes Unlike the add adenine riboswitch, the pbuE adenine riboswitch appears to exist in one of two stable conformations. Binding of adenine causes the formation of an antiterminator, thus allowing transcription to finish to completion. In the absence of adenine, the aptamer domain of the riboswitch instead associates with the riboswitch expression platform, leading to transcription termination.
Guanine Riboswitch:
The Guanine Riboswitch selectively recognizes guanine, and contains a cytosine ribonucleotide in position 74 of the guanine-binding aptamer domain. One of the more frequently researched instances of this riboswitch is detailed below.
Guanine Riboswitch:
xpt The xpt gene encodes a specific xanthine phosphoribosyltransferase protein, which is involved in purine metabolism. Unlike the add gene or the pbuE gene, ligand binding to the xpt guanine riboswitch serves as a translational off-switch. The xpt guanine riboswitch aptamer is stabilized by guanine in a way that allows the riboswitch to more easily bind magnesium, which causes folding of the mRNA such that the xpt gene ceases to be translated.
Practical utility:
Like other riboswitches, purine riboswitches are found in the five prime untranslated region (5' UTR) of prokaryotic mRNA. Since the function of this region is important to bacterial metabolism, purine riboswitches constitute a potentially useful drug target. Moreover, the purine riboswitch is the only riboswitch so far that has been mutated to respond to non-natural ligands, opening up possibilities to use riboswitches as novel gene-expression tools. | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**Friability**
Friability:
In materials science, friability ( FRY-ə-BIL-ə-tee), the condition of being friable, describes the tendency of a solid substance to break into smaller pieces under duress or contact, especially by rubbing. The opposite of friable is indurate.
Substances that are designated hazardous, such as asbestos or crystalline silica, are often said to be friable if small particles are easily dislodged and become airborne, and hence respirable (able to enter human lungs), thereby posing a health hazard.
Friability:
Tougher substances, such as concrete, may also be mechanically ground down and reduced to finely divided mineral dust. However, such substances are not generally considered friable because of the degree of difficulty involved in breaking the substance's chemical bonds through mechanical means. Some substances, such as polyurethane foams, show an increase in friability with exposure to ultraviolet radiation, as in sunlight.
Friability:
Friable is sometimes used metaphorically to describe "brittle" personalities who can be "rubbed" by seemingly-minor stimuli to produce extreme emotional responses.
General:
A friable substance is any substance that can be reduced to fibers or finer particles by the action of a small amount of pressure or friction, such as rubbing or inadvertently brushing up against the substance. The term could also apply to any material that exhibits these properties, such as: Ionically bound substances that are less than 1 kg/L in density Clay tablets Crackers Mineral fibers Polyurethane (foam) Aerogel
Geological:
Friable and indurated are terms used commonly in soft-rock geology, especially with sandstones, mudstones, and shales to describe how well the component rock fragments are held together.
Examples: Clumps of dried clay Chalk Perlite
Medical:
The term friable is also used to describe tumors in medicine. This is an important determination because tumors that are easily torn apart have a higher risk of malignancy and metastasis.
Examples: Some forms of cancer, such as atrial myxoma An inflamed gallbladder
Pharmaceutical:
Friability testing is a laboratory technique used by the pharmaceutical industry to test the durability of tablets during transit. This testing involves repeatedly dropping a sample of tablets over a fixed time, using a rotating wheel with a baffle. The result is inspected for broken tablets, and the percentage of tablet mass lost through chipping. A typical specification will allow a non-zero percentage of chipping, and zero broken tablets. | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**Recycle Track Systems**
Recycle Track Systems:
Recycle Track Systems (RTS) is an environmentally-focused waste and recycling management company. RTS uses a software platform and a proprietary tracking system to provide hauling services for businesses. A patent is pending. RTS tracks materials as they travel to recycling or composting facilities and provides companies with reports that show how much material was recycled or composted. The customer experience has been compared the app-based car service, Uber.
History:
RTS was co-founded by CEO Gregory Lettieri and COO Adam Pasquale in 2014. Pasquale is a fourth-generation member of a New York waste-hauling family, and his great-grandfather started in the garbage business with pushcarts on Mulberry Street in Manhattan's Little Italy in the early 1900s. Lettieri is a native of Staten Island and formerly worked in technology at Bank of America. Long-time friends, the two came up with the idea for the company in 2014.In June 2017, the company closed a series A financing round worth $11.7 million with Boston-based growth equity firm Volition Capital, the former U.S. team of Fidelity Ventures. Volition also provided the first outside money into Chewy, a pet supplies company that sold to PetSmart.Shazi Visram is an investor and board member of Recycle Track Systems, an American entrepreneur, investor, and philanthropist, best known as the founder, CEO, and Chief Mom of Happy Family Brands. Visram is a mentor for startups and an impact venture investor, with investments in EpiBone, Ovia Health, Simple Mills and Bulletproof. Lew Frankfort, the former chairman and CEO of Coach, Inc., is also a board member.RTS customers include Whole Foods, WeWork, SoulCycle, Barclays Center, Citi Field, Nationals Park and Audi Field.
History:
Impact In 2018, RTS donated 17,952 square feet of wood and 27 rolls of unused synthetic snow from the NHL Winter Classic game held at Citi Field to Materials for the Arts, a Long Island City-based program of the Department of Cultural Affairs that supports non-profit organizations and public schools throughout New York City.
RTS has donated approximately 66,000 pounds of food waste for Washington Nationals in the 2018 season.
RTS is a certified B Corporation.
Awards:
RTS was honored in the Best for Environment list, based on an independent, comprehensive assessment administered by the nonprofit B Lab, the organization that certifies B Corporations. | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**Faltings' product theorem**
Faltings' product theorem:
In arithmetic geometry, Faltings' product theorem gives sufficient conditions for a subvariety of a product of projective spaces to be a product of varieties in the projective spaces. It was introduced by Faltings (1991) in his proof of Lang's conjecture that subvarieties of an abelian variety containing no translates of non-trivial abelian subvarieties have only finitely many rational points.
Evertse (1995) and Ferretti (1996) gave explicit versions of Faltings' product theorem. | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**Supernatural Wiki**
Supernatural Wiki:
Supernatural Wiki, also known as SuperWiki, is a wiki-powered online encyclopedia for the CW's horror television series Supernatural, associated projects and events.
The site was launched on August 6, 2006, using MediaWiki software to maintain a user-created database of information. Supernatural Wiki and its domain, supernaturalwiki.com is hosted by a fan who accepts donations to hosting costs but makes no profit from running the site.As of June 18, 2021 the site contained 4,244 articles
Overview:
Supernatural Wiki was launched on August 12, 2006, following the first season of Supernatural. originally managed by a collective of fans, since 2008 the administrator of the site has been Australian fan Jules Wilkinson. The site provides detailed episode synopses, character biographies, pop culture and music references, information on folklore and religion as well as information on the cast and crew. It also documents tie-in material including official novels, magazines, and associated web-material.
Overview:
Unique amongst wiki sites for TV series, Supernatural Wiki also documents the show's Fandom. This includes creative works such as fan fiction including slash fiction, fan videos, fan art, fanzines and other fan-works. Fandom activities such as fan conventions – both fan-run and professional conventions attended by the cast and crew – are covered as well as are fan websites, media blogs and charity fund-raising. The history and culture of the Supernatural fandom is documented, including the Argot peculiar to this fandom.Additionally the site conducts interviews with the production staff on the show and also runs events during conventions such as San Diego Comic-Con International called "Wayward Cocktails" which bring the fans, cast and crew of the show together.
Overview:
In 2019, there were 4.2 million visits to the site.
Impact:
Supernatural Wiki has been recognized by other media outlets as a source of information about the show and its fandom. The CW Source Blog said of the site: "They've collected and dissected nearly every aspect of the show, the behind-the-scenes world, and the fan community, and laid it out in stunning detail.". The SuperWiki has also been referenced by media critics such as the Chicago Tribune's Maureen Ryan for its coverage of conventions such as San Diego Comic-Con International.The site has become an information resource by writers, production staff and cast. Writer Robbie Thompson called it an "indispensable" resource. Star Jared Padalecki said "I'm on the show, and I'm on (Supernatural Wiki) more than once a week researching it."The site was credited by author Keith R. A. DeCandido in the acknowledgments to his Supernatural tie-in novel Nevermore.
Impact:
In February 2009, the site established a Twitter presence at @SuperWiki. As of 18 June, 2021, the site has 108, 313 followers, including many of the cast and crew from Supernatural.
On 7 September 2009, in the lead up to the start of Season 5, @SuperWiki started ending tweets with the tag #luciferiscoming, and suggested fans do the same as a mischievous way to get attention for the show.
Impact:
The tag #luciferiscoming reached number 1 of the trending topics on Twitter. Rapper Sean Combs (@iamdiddy who has over a million followers), unaware of the context of #luciferiscoming and assuming it was an anti-Christian movement, started a #Godishere tweet in retaliation. Twitter moved to stop posts with tags including both God and Lucifer from appearing in trending topics. Fans continued to use #supernatural and #inkripkewetrust, and both also reached high on the list of trending topics.
Awards:
In April 2011 the site won the SFX (magazine) Best Franchise Specific website award beating out chucktv.net, The One Ring, Leaky Cauldron, Life, Doctor Who And Combom, and WhoFix.
Awards:
SFX Magazine described the site as "The most comprehensive Supernatural site on the web, established in 2006, Supernatural Wiki is a well laid-out, intelligently designed, easy to navigate Aladdin's cave of Winchester goodness."In 2014, the site was a board nominated finalist in the Shorty Social Media Awards.At the end of the 15th and final season of Supernatural, the site was awarded a special plaque by Warner Brothers Entertainment for the coverage and support of the show. | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**Residual topology**
Residual topology:
In chemistry, mechanically interlocked molecular architectures (MIMAs) are molecules that are connected as a consequence of their topology. This connection of molecules is analogous to keys on a keychain loop. The keys are not directly connected to the keychain loop but they cannot be separated without breaking the loop. On the molecular level, the interlocked molecules cannot be separated without the breaking of the covalent bonds that comprise the conjoined molecules; this is referred to as a mechanical bond. Examples of mechanically interlocked molecular architectures include catenanes, rotaxanes, molecular knots, and molecular Borromean rings. Work in this area was recognized with the 2016 Nobel Prize in Chemistry to Bernard L. Feringa, Jean-Pierre Sauvage, and J. Fraser Stoddart.The synthesis of such entangled architectures has been made efficient by combining supramolecular chemistry with traditional covalent synthesis, however mechanically interlocked molecular architectures have properties that differ from both "supramolecular assemblies" and "covalently bonded molecules". The terminology "mechanical bond" has been coined to describe the connection between the components of mechanically interlocked molecular architectures. Although research into mechanically interlocked molecular architectures is primarily focused on artificial compounds, many examples have been found in biological systems including: cystine knots, cyclotides or lasso-peptides such as microcin J25 which are proteins, and a variety of peptides.
Residual topology:
Residual topology is a descriptive stereochemical term to classify a number of intertwined and interlocked molecules, which cannot be disentangled in an experiment without breaking of covalent bonds, while the strict rules of mathematical topology allow such a disentanglement. Examples of such molecules are rotaxanes, catenanes with covalently linked rings (so-called pretzelanes), and open knots (pseudoknots) which are abundant in proteins.
Residual topology:
The term "residual topology" was suggested on account of a striking similarity of these compounds to the well-established topologically nontrivial species, such as catenanes and knotanes (molecular knots). The idea of residual topological isomerism introduces a handy scheme of modifying the molecular graphs and generalizes former efforts of systemization of mechanically bound and bridged molecules.
History:
Experimentally the first examples of mechanically interlocked molecular architectures appeared in the 1960s with catenanes being synthesized by Wasserman and Schill and rotaxanes by Harrison and Harrison. The chemistry of MIMAs came of age when Sauvage pioneered their synthesis using templating methods. In the early 1990s the usefulness and even the existence of MIMAs were challenged. The latter concern was addressed by X ray crystallographer and structural chemist David Williams. Two postdoctoral researchers who took on the challenge of producing [5]catenane (olympiadane) pushed the boundaries of the complexity of MIMAs that could be synthesized their success was confirmed in 1996 by a solid‐state structure analysis conducted by David Williams.
Mechanical bonding and chemical reactivity:
The introduction of a mechanical bond alters the chemistry of the sub components of rotaxanes and catenanes. Steric hindrance of reactive functionalities is increased and the strength of non-covalent interactions between the components are altered.
Mechanical bonding and chemical reactivity:
Mechanical bonding effects on non-covalent interactions The strength of non-covalent interactions in a mechanically interlocked molecular architecture increases as compared to the non-mechanically bonded analogues. This increased strength is demonstrated by the necessity of harsher conditions to remove a metal template ion from catenanes as opposed to their non-mechanically bonded analogues. This effect is referred to as the "catenand effect". This increase in strength of non-covalent interactions is attributed to the loss of degrees of freedom upon the formation of a mechanical bond. The increase in strength of non-covalent interactions is more pronounced on smaller interlocked systems, where more degrees of freedom are lost, as compared to larger mechanically interlocked systems where the change in degrees of freedom is lower. Therefore, if the ring in a rotaxane is made smaller the strength of non-covalent interactions increases, the same effect is observed if the thread is made smaller as well.
Mechanical bonding and chemical reactivity:
Mechanical bonding effects on chemical reactivity The mechanical bond can reduce the kinetic reactivity of the products, this is ascribed to the increased steric hindrance. Because of this effect hydrogenation of an alkene on the thread of a rotaxane is significantly slower as compared to the equivalent non interlocked thread. This effect has allowed for the isolation of otherwise reactive intermediates.
Mechanical bonding and chemical reactivity:
The ability to alter reactivity without altering covalent structure has led to MIMAs being investigated for a number of technological applications.
Applications of mechanical bonding in controlling chemical reactivity The ability for a mechanical bond to reduce reactivity and hence prevent unwanted reactions has been exploited in a number of areas. One of the earliest applications was in the protection of organic dyes from environmental degradation. | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**Ubercode**
Ubercode:
Ubercode is a high level programming language designed by Ubercode Software and released in 2005 for Microsoft Windows. Ubercode is influenced by Eiffel and BASIC. It is proprietary software and can be tried out for free for 30 days. Ubercode has the following design goals: Compilable language—compiled into Windows EXE files.
Automatic memory management—memory is allocated / freed automatically, and the language has no memory management primitives.
Pre and post conditions—these are run-time assertions which are attached to function declarations, as in Eiffel.
High-level data types—resizable arrays, lists and tables may contain arbitrary components.
Integrated file handling—primitives for transparent handling of text, binary, CSV, XML and dBase files.
Ease of use—language structure is relatively simple, making the language accessible to beginners.
Hello, World!:
Here is the basic "Hello, World!" program: Ubercode 1 class Hello public function main() code call Msgbox("Hello", "Hello World!") end function end class
Preconditions and Postconditions:
Here is an example using pre- and postconditions. In the example, the IntToStr function validates its input as a string before converting it to an integer: Ubercode 1 class PrePost function IntToStr(in mystr:string[*] out value:integer) precond IsDigitStr(mystr) code call Val(mystr, value) end function public function main() code call Msgbox("OOP example", "IntToStr(10) = " + IntToStr("10")) end function end class | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**Show building**
Show building:
Show building is the name often given to various enclosed structures at theme parks that contain attractions such as rides and entertainment shows. The exteriors of such buildings may be themed on some or all sides, but their hidden "backstage" areas are normally very utilitarian, resembling warehouses or sound stages.
Architectural features:
Unthemed areas of show buildings typically have simple, practical walls with flat roofs. Doors allow employees to enter and exit, and provide exits for guests during emergency or temporary ride shutdowns. One or more ladders and/or stairwells are often installed for roof access, and sometimes for access to scenes or backstage rooms that are located above ground level. Louvers, downspouts, electrical cables, and artificial lighting (often wall packs) are common sights as well.
Maintaining the illusion:
Techniques vary for hiding the buildings' industrial nature from the eyes of park guests. The most common ways include planting foliage to obstruct the views, adding themed exteriors to the visible areas, painting visible surfaces with colors that blend with the surroundings, and adding mounds of earth (berms) or solid walls between guests and buildings. They may also be built partially or completely below ground level. Disneyland, for instance, contains many show buildings, some of which are disguised on all sides. One example is the building containing Mr. Toad's Wild Ride, Peter Pan's Flight, and Alice in Wonderland, which features themed facades of castle walls and a quaint European village. At attractions such as the Haunted Mansion, most of the experience takes place in a green show building concealed behind a berm that separates it from the themed "mansion", with the two structures connected by an underground passageway. All of the Disney theme parks utilize similar techniques to some extent.
Maintaining the illusion:
Some theme parks take less rigorous approaches. Universal Studios Hollywood hides many of its show buildings in the same fashion, but other buildings, such as that housing Revenge of the Mummy, are allowed to remain (as a whole or in part) as real-world examples of utilitarian sound stages. Some parks make no attempt to hide show buildings from guests and/or people outside the property, usually due to the cost involved, space limitations, and/or lack of interest in hiding the structures. For instance, all the buildings of the Santa Cruz Beach Boardwalk are clearly visible from Beach Street, which passes directly behind them. Similarly, the show building at Knott's Berry Farm that formerly contained Kingdom of the Dinosaurs is clearly visible from Western Avenue, just a few yards away. | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**EPL2T multiple unit**
EPL2T multiple unit:
EPL2T (Ukrainian: ЕПЛ2Т) is a Ukrainian electric multiple unit for suburban commuter routes on lines electrified with 3 kV DC.
The design is based on the earlier ЕR2Т of the Latvian Rīgas Vagonbūves Rūpnīca in Riga, 35 units was manufactured by Luhanskteplovoz between 2000 and 2008. | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**Double bubble theorem**
Double bubble theorem:
In the mathematical theory of minimal surfaces, the double bubble theorem states that the shape that encloses and separates two given volumes and has the minimum possible surface area is a standard double bubble: three spherical surfaces meeting at angles of 120° on a common circle. The double bubble theorem was formulated and thought to be true in the 19th century, and became a "serious focus of research" by 1989, but was not proven until 2002.
Double bubble theorem:
The proof combines multiple ingredients. Compactness of rectifiable currents (a generalized definition of surfaces) shows that a solution exists. A symmetry argument proves that the solution must be a surface of revolution, and it can be further restricted to having a bounded number of smooth pieces. Jean Taylor's proof of Plateau's laws describes how these pieces must be shaped and connected to each other, and a final case analysis shows that, among surfaces of revolution connected in this way, only the standard double bubble has locally-minimal area.
Double bubble theorem:
The double bubble theorem extends the isoperimetric inequality, according to which the minimum-perimeter enclosure of any area is a circle, and the minimum-surface-area enclosure of any single volume is a sphere. Analogous results on the optimal enclosure of two volumes generalize to weighted forms of surface energy, to Gaussian measure of surfaces, and to Euclidean spaces of any dimension.
Statement:
According to the isoperimetric inequality, the minimum-perimeter enclosure of any area is a circle, and the minimum-surface-area enclosure of any single volume is a sphere. The existence of a shape with bounded surface area that encloses two volumes is obvious: just enclose them with two separate spheres. It is less obvious that there must exist some shape that encloses two volumes and has the minimum possible surface area: it might instead be the case that a sequence of shapes converges to a minimum (or to zero) without reaching it. This problem also raises tricky definitional issues: what is meant by a shape, the surface area of a shape, and the volume that it encloses, when such things may be non-smooth or even fractal? Nevertheless, it is possible to formulate the problem of optimal enclosures rigorously using the theory of rectifiable currents, and to prove using compactness in the space of rectifiable currents that every two volumes have a minimum-area enclosure.
Statement:
Plateau's laws state that any minimum area piecewise-smooth shape that encloses any volume or set of volumes must take a form commonly seen in soap bubbles in which surfaces of constant mean curvature meet in threes, forming dihedral angles of 120° ( 2π/3 radians). In a standard double bubble, three patches of spheres meet at this angle along a shared circle. Two of these spherical surfaces form the outside boundary of the double bubble and a third one in the interior separates the two volumes from each other. In physical bubbles, the radii of the spheres are inversely proportional to the pressure differences between the volumes they separate, according to the Young–Laplace equation. This connection between pressure and radius is reflected mathematically in the fact that, for any standard double bubble, the three radii r1 , r2 , and r3 of the three spherical surfaces obey the equation where r1 is the smaller radius of the two outer bubbles. In the special case when the two volumes and two outer radii are equal, calculating the middle radius using this formula leads to a division by zero. In this case, the middle surface is instead a flat disk, which can be interpreted as a patch of an infinite-radius sphere. The double bubble theorem states that, for any two volumes, the standard double bubble is the minimum area shape that encloses them; no other set of surfaces encloses the same amount of space with less total area.In the Euclidean plane, analogously, the minimum perimeter of a system of curves that enclose two given areas is formed by three circular arcs, with the same relation between their radii, meeting at the same angle of 120°. For two equal areas, the middle arc degenerates to a straight line segment. The three-dimensional standard double bubble can be seen as a surface of revolution of this two-dimensional double bubble. In any higher dimension, the optimal enclosure for two volumes is again formed by three patches of hyperspheres, meeting at the same 120° angle.
History:
The three-dimensional isoperimetric inequality, according to which a sphere has the minimum surface area for its volume, was formulated by Archimedes but not proven rigorously until the 19th century, by Hermann Schwarz. In the 19th century, Joseph Plateau studied the double bubble, and the truth of the double bubble theorem was assumed without proof by C. V. Boys in the 1912 edition of his book on soap bubbles. Plateau formulated Plateau's laws, describing the shape and connections between smooth pieces of surfaces in compound soap bubbles; these were proven mathematically for minimum-volume enclosures by Jean Taylor in 1976.By 1989, the double bubble problem had become a "serious focus of research". In 1991, Joel Foisy, an undergraduate student at Williams College, was the leader of a team of undergraduates that proved the two-dimensional analogue of the double bubble conjecture. In his undergraduate thesis, Foisy was the first to provide a precise statement of the three-dimensional double bubble conjecture, but he was unable to prove it.A proof for the restricted case of the double bubble conjecture, for two equal volumes, was announced by Joel Hass and Roger Schlafly in 1995, and published in 2000. The proof of the full conjecture by Hutchings, Morgan, Ritoré, and Ros was announced in 2000 and published in 2002. After earlier work on the four-dimensional case, the full generalization to higher dimensions was published by Reichardt in 2008, and in 2014, Lawlor published an alternative proof of the double bubble theorem generalizing both to higher dimensions and to weighted forms of surface energy. Variations of the problem considering other measures of the size of the enclosing surface, such as its Gaussian measure, have also been studied.
Proof:
A lemma of Brian White shows that the minimum area double bubble must be a surface of revolution. For, if not, one could use a similar argument to the ham sandwich theorem to find two orthogonal planes that bisect both volumes, replace surfaces in two of the four quadrants by the reflections of the surfaces in the other quadrants, and then smooth the singularities at the reflection planes, reducing the total area. Based on this lemma, Michael Hutchings was able to restrict the possible shapes of non-standard optimal double bubbles, to consist of layers of toroidal tubes.Additionally, Hutchings showed that the number of toroids in a non-standard but minimizing double bubble could be bounded by a function of the two volumes. In particular, for two equal volumes, the only possible nonstandard double bubble consists of a single central bubble with a single toroid around its equator. Based on this simplification of the problem, Joel Hass and Roger Schlafly were able to reduce the proof of this case of the double bubble conjecture to a large computerized case analysis, taking 20 minutes on a 1995 personal computer. The eventual proof of the full double bubble conjecture also uses Hutchings' method to reduce the problem to a finite case analysis, but it avoids the use of computer calculations, and instead works by showing that all possible nonstandard double bubbles are unstable: they can be perturbed by arbitrarily small amounts to produce another surface with lower area. The perturbations needed to prove this result are a carefully chosen set of rotations. Because a surface of minimum area exists, and none of the other candidate surfaces have minimum area, the minimum-area surface can only be the standard double bubble.
Related problems:
John M. Sullivan has conjectured that, for any dimension d , the minimum enclosure of up to d+1 volumes (not necessarily equal) has the form of a stereographic projection of a simplex. In particular, in this case, all boundaries between bubbles would be patches of spheres. The special case of this conjecture for three bubbles in two dimensions has been proven; in this case, the three bubbles are formed by six circular arcs and straight line segments, meeting in the same combinatorial pattern as the edges of a tetrahedron. Frank Morgan called even the case of three volumes in three dimensions "inaccessible", but in 2022 a proof was announced of the three-volume case in all dimensions, and of additional partial results in higher dimensions. Numerical experiments have shown that for six or more volumes in three dimensions, some of the boundaries between bubbles may be non-spherical.For an infinite number of equal areas in the plane, the minimum-length set of curves separating these areas is the hexagonal tiling, familiar from its use by bees to form honeycombs, and its optimality (the honeycomb conjecture) was proven by T. C. Hales in 2001. For the same problem in three dimensions, the optimal solution is not known; Lord Kelvin conjectured that it was given by a structure combinatorially equivalent to the bitruncated cubic honeycomb, but this conjecture was disproved by the discovery of the Weaire–Phelan structure, a partition of space into equal volume cells of two different shapes using a smaller average amount of surface area per cell.Researchers have also studied the dynamics of physical processes by which pairs of bubbles coalesce into a double bubble. This topic relates to a more general topic in differential geometry of the dynamic behavior of curves and surfaces under different processes that change them continuously. For instance, the curve-shortening flow is a process in which curves in the plane move at a speed proportionally to their curvature. For two infinite regions separated by a line, with a third finite region between them, the curve-shortening flow on their boundaries (rescaled to preserve the area of the finite region) converges towards a limiting shape in the form of a degenerate double bubble: a vesica piscis along the line between the two unbounded regions. | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**Pecom 64**
Pecom 64:
Pecom 64 was an educational and/or home computer developed by Elektronska Industrija Niš of Serbia in 1985.
Specifications:
CPU: CDP 1802B 5V7 running at 2.813 MHz ROM: 16 KB, with optional 16 KB upgrade containing enhanced editor and assembler RAM: 32 KB Secondary storage: cassette tape VIS: (Video Interface System) CDP1869 / CDP1870 Text modes: 40 columns x 24 lines Character set: 128 Programmable characters Character size: 6x9 pixels Graphics modes: None, but the character-set was re programmable (semigraphics) to simulate a 240x216 High Resolution display Colours: A total of 8 foreground colours are available (with a limited choice of 4 per character and 1 per line of that character) and 8 background colours (defined for the whole screen).
Specifications:
Sound: 2 channels: one for tone generation with a span of 8 octaves, and 1 for special effect/white noise. Volume programmable in 16 steps.
I/O ports:cassette tape storage, composite and RF video, RS-232 and expansion connector Power supply: 220V AC, 0.02 A, 4.5 W (built-in transformer) | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**Reederite-(Y)**
Reederite-(Y):
Reederite-(Y) is a rare mineral with the formula (Na,Mn,Fe)15(Y,REE)2(CO3)9(SO3F)Cl. It is the only known mineral with fluorosulfate (fluorosulfonate). "REE" in the formula stands for rare earth elements other than yttrium, that is mostly cerium, with traces of neodymium, dysprosium, lanthanum and erbium. The formula also includes a Levinson suffix "-(Y)" pointing to the dominance of yttrium at the corresponding site. Reederite-(Y) crystallizes in the hexagonal crystal system with the space group P6, rarely seen among minerals. | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**Short hairpin RNA**
Short hairpin RNA:
A short hairpin RNA or small hairpin RNA (shRNA/Hairpin Vector) is an artificial RNA molecule with a tight hairpin turn that can be used to silence target gene expression via RNA interference (RNAi). Expression of shRNA in cells is typically accomplished by delivery of plasmids or through viral or bacterial vectors. shRNA is an advantageous mediator of RNAi in that it has a relatively low rate of degradation and turnover. However, it requires use of an expression vector, which has the potential to cause side effects in medicinal applications.The promoter choice is essential to achieve robust shRNA expression. At first, polymerase III promoters such as U6 and H1 were used; however, these promoters lack spatial and temporal control. As such, there has been a shift to using polymerase II promoters, which are inducible, to regulate shRNA expression.
Delivery:
Expression of shRNA in cells can be obtained by delivery of plasmids or through viral or bacterial vectors.
Delivery of plasmids to cells through transfection to obtain shRNA expression can be accomplished using commercially available reagents in vitro. However, this method is not applicable in vivo and thus has limited utility.
Delivery:
Use of a bacterial vector to obtain shRNA expression in cells is a relatively recent approach. It builds off research showing that recombinant Escherichia coli, containing a plasmid with shRNA, fed to mice can knock-down target gene expression in the intestinal epithelium. This approach was used in 2012 in clinical trials to try to treat patients with Familial Adenomatous Polyposis.A variety of viral vectors can be used to obtain shRNA expression in cells including adeno-associated viruses (AAVs), adenoviruses, and lentiviruses. With adeno-associated viruses and adenoviruses, the genomes remain episomal. This is advantageous as insertional mutagenesis is avoided. It is disadvantageous in that the progeny of the cell will lose the virus quickly through cell division unless the cell divides very slowly. AAVs differ from adenoviruses in that the viral genes have been removed and they have diminished packing capacity. Lentiviruses integrate into sections of transcriptionally active chromatin and are thus passed on to progeny cells. With this approach there is increased risk of insertional mutagenesis; however, the risk can be reduced by using an integrase-deficient lentivirus.
Mechanism of action:
Once the vector has integrated into the host genome, the shRNA is then transcribed in the nucleus by polymerase II or polymerase III depending on the promoter choice. The product mimics pri-microRNA (pri-miRNA) and is processed by Drosha. The resulting pre-shRNA is exported from the nucleus by Exportin 5. This product is then processed by Dicer and loaded into the RNA-induced silencing complex (RISC). The sense (passenger) strand is degraded. The antisense (guide) strand directs RISC to mRNA that has a complementary sequence. In the case of perfect complementarity, RISC cleaves the mRNA. In the case of imperfect complementarity, RISC represses translation of the mRNA. In both of these cases, the shRNA leads to target gene silencing.
Applications in gene therapy:
Due to the ability of shRNA to provide specific, long-lasting, gene silencing there has been great interest in using shRNA for gene therapy applications. Three examples of shRNA-based therapies are discussed below.
Applications in gene therapy:
Gradalis, Inc. developed the FANG vaccine, which is used in treatment of advanced cancers. FANG relies on a bifunctional shRNA (bi-shRNA) against the immunosuppressive transforming growth factors (TGF) β1 and β2. Autologous tumor cells were harvested from patients and a plasmid encoding the bifunctional shRNA and granulocyte-macrophage colony-stimulating factor (GMCSF) was introduced ex vivo through electroporation. These cells were later irradiated and injected back into the patient.
Applications in gene therapy:
Marina Biotech developed CEQ508 which is used to treat Familial Adenomatous Polyposis. CEQ508 uses a bacterial vector to deliver shRNA against β-catenin.
Gradalis, Inc. developed bifunctional shRNA-STMN1 (pbi-shRNA STMN1), which is used to treat advanced and/or metastatic cancers. This pbi-shRNA STMN1 is against stathmin 1 and is delivered intratumorally through bilamellar invaginated vesicle (BIV) lipoplex (LP) technology.
Applications in gene therapy:
Several challenges typically confront shRNA-based therapeutics. The most significant challenge is delivery. shRNA is typically delivered through use of a vector, and although they are generally efficient, they pose significant safety concerns. In particular, viral based gene therapy approaches have proved dangerous in past clinical trials. In the first generation of retro viral gene therapy, some patients treated with viral vectors for Wiskott–Aldrich syndrome developed acute T-cell leukaemia. This was determined to have been caused by viral vector insertion location. Potential oversaturation of RISC is also a problem. If the shRNA is expressed at levels that are too high, the cell might not be able to correctly process the endogenous RNA which could cause significant problems. Another challenge is the possibility that the patient might mount an immune response against the therapy. Finally, there might be off-target effects and the shRNA could silence other unintended genes. In developing successful new shRNA-based therapeutics, all of these challenges must be taken into account. | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**Canadian High Arctic Ionospheric Network**
Canadian High Arctic Ionospheric Network:
The Canadian High Arctic Ionospheric Network (CHAIN) is an array of ground-based radio instruments deployed in the Canadian Arctic and operated by the University of New Brunswick. The CHAIN instruments include high data-rate GPS receivers and digital ionosondes. After passing through the Earth's ionosphere, microwave GPS signals carry information about the total electron content (TEC). This information is commonly used to improve the precision of GPS and to study ionospheric morphology. Ionosondes transmit pulses of radio signals in the Medium Frequency (MF) and High Frequency (HF) ranges, whose echos are analyzed to measure height and density of the ionosphere. Advanced digital ionosondes used in the CHAIN network are also able to measure the bulk motion of ionospheric plasma.Most of the CHAIN instruments are located within the polar cap defined as a region of open magnetic field lines. The polar cap ionosphere is directly linked to the interplanetary magnetic field carried by the solar wind. Polar cap thus provides a vantage point for the study of energy exchange between the solar wind, magnetosphere and ionosphere.
Canadian High Arctic Ionospheric Network:
CHAIN is an integral part of the Canadian Geospace Monitoring (CGSM) programme. It provides ground support for Canadian and international scientific space missions such as THEMIS and CASSIOPE. CHAIN ionosonde and GPS data are used for tomographic reconstructions of polar cap plasma anomalies during geomagnetic storms In January 2012, the Canada Foundation for Innovation announced funding for the Expanded Canadian High-Arctic Ionospheric Network (ECHAIN). This funding was used to add 15 Global Positioning System (GPS) receivers to the existing network of GPS receivers and radars of the Canadian High Arctic Ionospheric Network (CHAIN). The data will contribute significantly to the progress of space research by providing a better understanding of the processes in the Sun-Earth system. | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**Virtual tape library**
Virtual tape library:
A virtual tape library (VTL) is a data storage virtualization technology used typically for backup and recovery purposes. A VTL presents a storage component (usually hard disk storage) as tape libraries or tape drives for use with existing backup software.
Virtualizing the disk storage as tape allows integration of VTLs with existing backup software and existing backup and recovery processes and policies. The benefits of such virtualization include storage consolidation and faster data restore processes. For most mainframe data centers, the storage capacity varies, however protecting its business and mission critical data is always vital.
Most current VTL solutions use SAS or SATA disk arrays as the primary storage component due to their relatively low cost. The use of array enclosures increases the scalability of the solution by allowing the addition of more disk drives and enclosures to increase the storage capacity.
The shift to VTL also eliminates streaming problems that often impair efficiency in tape drives as disk technology does not rely on streaming and can write effectively regardless of data transfer speeds.
Virtual tape library:
By backing up data to disks instead of tapes, VTL often increases performance of both backup and recovery operations. Restore processes are found to be faster than backup regardless of implementations. In some cases, the data stored on the VTL's disk array is exported to other media, such as physical tapes, for disaster recovery purposes (scheme called disk-to-disk-to-tape, or D2D2T).
Virtual tape library:
Alternatively, most contemporary backup software products introduced also direct usage of the file system storage (especially network-attached storage, accessed through NFS and CIFS protocols over IP networks) not requiring a tape library emulation at all. They also often offer a disk staging feature: moving the data from disk to a physical tape for a long-term storage.
Virtual tape library:
While a virtual tape library is very fast, the disk storage within is not designed to be removable, and does not usually involve physically removable external disk drives to be used for data archiving in place of tape. Since the disk storage is always connected to power and data sources and is never physically electrically isolated, it is vulnerable to potential damage and corruption due to nearby building or power grid lightning strikes.
History:
The first VTL solution was introduced by Cybernetics in 1992 under the name HSTC (high speed tape cache). Later, IBM released a Virtual Tape Server (VTS) introduced in 1997. It was targeted for a mainframe market, where many legacy applications tend to use a lot of very short tape volumes. It used the ESCON interface, and acted as a disk cache for the IBM 3494 tape library. A competitive offering from StorageTek (acquired in 2005 by Sun Microsystems, then subsequently by Oracle Corporation) was known as Virtual Storage Manager (VSM) which leveraged the market dominant STK Powderhorn library as a back store. Each product line has been enhanced to support larger disk buffer capacities, FICON, and more recently (c. 2010) "tapeless" disk-only environments.
History:
Other offerings in the mainframe space are also "tapeless". DLm has been developed by EMC Corporation, while Luminex has gained popularity and wide acceptance by teaming with Data Domain to provide the benefits of data deduplication behind its Channel Gateway platform. With the consequent reduction in off-site replication bandwidth afforded by deduplication, it is possible and practical for this form of virtual tape to reduce recovery point objective time and recovery time objective to near zero (or instantaneous).
History:
Outside of the mainframe environment, tape drives and libraries mostly featured SCSI. Likewise, VTLs were developed supporting popular SCSI transport protocols such as SPI (legacy systems), Fibre Channel, and iSCSI.
History:
The FalconStor VTL is the foundation of nearly half of the products sold in the VTL market, according to an Enterprise Strategy Group analyst.In mid-2010s VTLs got a rebirth thanks to hi-capacity "archive" drives from Seagate and HGST and more popular "tape in cloud" and Disk-to-Disk-to-Tape (often in cloud) scenarios. Amazon and StarWind Software in partnership with Veeam, BackBlaze and Wasabi Technologies offer a so-called gateway products that facilitates backing up and archiving "on premises" data as virtual tapes stored in AWS, Microsoft Azure, Wasabi Technologies and BackBlaze public clouds. The idea is to provide a seamless integration of a backup applications incompatible with the APIs object storages expose. Say, at the time Veeam couldn't do AWS S3 and can't backup to the deep archive tier within Azure still. | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**Leica Digilux 3**
Leica Digilux 3:
The Digilux 3 is a digital single-lens reflex camera introduced by Leica on 14 September 2006. The Digilux 3 and the Panasonic Lumix DMC-L1 are similar specification cameras, using the Four Thirds standard lens mount and featuring a 7.5 Megapixels live view N-MOS sensor, but the Digilux 3 has modified firmware including DNG output. Both the Panasonic and Digilux 3 cameras come standard with the same interchangeable Leica Elmarit 14–50 mm f/2.8–3.5 optically image-stabilized zoom lens. The Leica D system includes also the Leica Summilux 25 mm f/1.4 lens.The two cameras share several unique features among dSLRs. One is the presence of film-camera type controls for optional control of both aperture and shutter speed. Reviews have noted the intuitive "feel" of the cameras.
Leica Digilux 3:
Another is the built-in dual-position flash. With an initial actuation of the flash button, the flash pops up to a bounce-flash position, giving a more diffuse flash that is preferred by some photographers, especially for portrait photos. A second actuation of the button raises the flash to a forward-facing position for direct flash. Some of the build features are inherited from the Olympus E-330, such as the eyepiece. Spare parts, such as the EP-7 eyecup from Olympus, can be used on the Digilux 3.
Leica Digilux 3:
The camera also includes a comprehensive software package Adobe® Photoshop® Elements® 4.0 and Quicktime movie player. Only 13,300 of these cameras were made, making it somewhat rare. (W x H x D without lens) - 145.8 x 86.9 x 80 mm Weight (camera body) - approx. 530 g. Designed by Achim Heine, Berlin.(Leica), Electronics by Matsushita/Olympus | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**Vestibular papillomatosis**
Vestibular papillomatosis:
Vestibular papillomatosis (VP) are normal small bumps in the genital area of females. The bumps appear in multiple numbers, are rounded and are not painful, itchy or uncomfortable. They are comparable to pearly penile papules, which occur in males.VP are not infectious and not due to HPV. Diagnosis is by visualization. The bumps are less yellow and more pinkish when compared to Fordyce spots. They should not be mistaken for genital warts. No treatment is required.They are common in pregnancy. Historically they were sometimes incorrectly called "microwarts". | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**Lists of molecules**
Lists of molecules:
This is an index of lists of molecules (i.e. by year, number of atoms, etc.). Millions of molecules have existed in the universe since before the formation of Earth. Three of them, carbon dioxide, water and oxygen were necessary for the growth of life. Although humanity had always been surrounded by these substances, it has not always known what they were composed of.
By century:
The following is an index of list of molecules organized by time of discovery of their molecular formula or their specific molecule in case of isomers:
By number of carbon atoms in the molecule:
List of compounds with carbon number 1 List of compounds with carbon number 2 List of compounds with carbon number 3 List of compounds with carbon number 4 List of compounds with carbon number 5 List of compounds with carbon number 6 List of compounds with carbon number 7 List of compounds with carbon number 8 List of compounds with carbon number 9 List of compounds with carbon number 10 List of compounds with carbon number 11 List of compounds with carbon number 12 List of compounds with carbon number 13 List of compounds with carbon number 14 List of compounds with carbon number 15 List of compounds with carbon number 16 List of compounds with carbon number 17 List of compounds with carbon number 18 List of compounds with carbon number 19 List of compounds with carbon number 20 List of compounds with carbon number 21 List of compounds with carbon number 22 List of compounds with carbon number 23 List of compounds with carbon number 24 List of compounds with carbon numbers 25-29 List of compounds with carbon numbers 30-39 List of compounds with carbon numbers 40-49 List of compounds with carbon numbers 50+
Other lists:
List of interstellar and circumstellar molecules List of gases List of molecules with unusual names | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**Record press**
Record press:
A record press is a machine for manufacturing vinyl records. It is essentially a hydraulic press fitted with thin nickel stampers which are negative impressions of a master disc. Labels and a pre-heated vinyl patty (or "biscuit") are placed in a heated mold cavity. Two stampers are used, one for each of side of the disc. The record press closes under a pressure of about 150 tons. The process of compression molding forces the hot vinyl to fill the grooves in the stampers, and take the form of the finished record.
Vacuum molding:
In the mid-1960s, Emory Cook developed a system of record forming wherein the mold pressure was replaced by a vacuum. In this technique, the mold cavity was evacuated and vinyl was introduced in micro-particle form. The particles were then flash-fused instantaneously at a high temperature forming a coherent solid. Cook called this disc manufacturing technology microfusion. A small pressing plant in Hollywood also employed a similar system which they maintained fused the particles more evenly throughout the disc thickness calling their product polymax. Both claimed the resultant disc grooves exhibited less surface noise and greater resistance to deformation from stylus tip inertia than convention pressure molded vinyl discs. | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**Thoracic diaphragm**
Thoracic diaphragm:
The thoracic diaphragm, or simply the diaphragm (; Ancient Greek: διάφραγμα, romanized: diáphragma, lit. 'partition'), is a sheet of internal skeletal muscle in humans and other mammals that extends across the bottom of the thoracic cavity. The diaphragm is the most important muscle of respiration, and separates the thoracic cavity, containing the heart and lungs, from the abdominal cavity: as the diaphragm contracts, the volume of the thoracic cavity increases, creating a negative pressure there, which draws air into the lungs. Its high oxygen consumption is noted by the many mitochondria and capillaries present; more than in any other skeletal muscle.The term diaphragm in anatomy, created by Gerard of Cremona, can refer to other flat structures such as the urogenital diaphragm or pelvic diaphragm, but "the diaphragm" generally refers to the thoracic diaphragm. In humans, the diaphragm is slightly asymmetric—its right half is higher up (superior) to the left half, since the large liver rests beneath the right half of the diaphragm. There is also speculation that the diaphragm is lower on the other side due to heart's presence.
Thoracic diaphragm:
Other mammals have diaphragms, and other vertebrates such as amphibians and reptiles have diaphragm-like structures, but important details of the anatomy may vary, such as the position of the lungs in the thoracic cavity.
Structure:
The diaphragm is an upward curved, c-shaped structure of muscle and fibrous tissue that separates the thoracic cavity from the abdomen. The superior surface of the dome forms the floor of the thoracic cavity, and the inferior surface the roof of the abdominal cavity.As a dome, the diaphragm has peripheral attachments to structures that make up the abdominal and chest walls. The muscle fibres from these attachments converge in a central tendon, which forms the crest of the dome. Its peripheral part consists of muscular fibers that take origin from the circumference of the inferior thoracic aperture and converge to be inserted into a central tendon.
Structure:
The muscle fibres of the diaphragm emerge from many surrounding structures and can be divided into vertebral, costal, sternal, and central tendon.The vertebral part of the diaphragram arises from the crura and arcuate ligaments. Right crus arises from L1-L3 vertebral bodies and their intervertebral discs. Smaller left crus arises from L1, L2 vertebral bodies and their intervertebral discs. Medial arcuate ligament arises from the fascia thickening from body of L2 vertebrae to transverse process of L1 vertebrae, crossing over the body of the psoas major muscle. The lateral arcuate ligament arises from the transverse process of L1 vertebrae and is attached laterally to the 12th rib. The lateral arcuate ligament also arises from fascia thickening that covers the quadratus lumborum muscle. The median arcuate ligament arises from the fibrous parts of right and left crura where descending thoracic aorta passes behind it. No diaphramatic muscle arises from the median arcuate ligament. Both adrenal glands lie the near diaphragmatic crus and arcuate ligament.The costal part of diaphragm arises from the lower four ribs (7 to 10) costal cartilages.The central tendon of the diaphragm is a thin but strong aponeurosis near the center of the vault formed by the muscle, closer to the front than to the back of the thorax. The central part of the tendon is attached above to pericardium. The both sides of the posterior fibres are attached to paracolic gutters (the curving of ribs before attaching to both sides of the vertebral bodies).
Structure:
Openings There are a number of openings in the diaphragm through which structures pass between the thorax and abdomen. There are three large openings — one for the aorta (aortic hiatus), one for the esophagus (esophageal hiatus), and one for the inferior vena cava (the caval opening), as well as a series of smaller openings.
Structure:
The inferior vena cava passes through the caval opening, a quadrilateral opening at the junction of the right and middle leaflets of the central tendon, so that its margins are tendinous. Surrounded by tendons, the opening is stretched open every time inspiration occurs. However, there has been argument that the caval opening actually constricts during inspiration. Since thoracic pressure decreases upon inspiration and draws the caval blood upwards toward the right atrium, increasing the size of the opening allows more blood to return to the heart, maximizing the efficacy of lowered thoracic pressure returning blood to the heart. The aorta does not pierce the diaphragm but rather passes behind it in between the left and right crus.There are several structures that pierce through the diaphragm, including: left phrenic nerve pierces through the central tendon, greater, lesser, and least thoracic splanchnic nerves pierces through bilateral crura, and lymphatic vessels that pierce throughout the diaphragam, especially behind the diaphragm.
Structure:
Nerve supply The diaphragm is primarily innervated by the phrenic nerve which is formed from the cervical nerves C3, C4 and C5. While the central portion of the diaphragm sends sensory afferents via the phrenic nerve, the peripheral portions of the diaphragm send sensory afferents via the intercostal (T5–T11) and subcostal nerves (T12).
Blood supply Arteries and veins above and below the diaphragm supply and drain blood.
Structure:
From above, the diaphragm receives blood from branches of the internal thoracic arteries, namely the pericardiacophrenic artery and musculophrenic artery; from the superior phrenic arteries, which arise directly from the thoracic aorta; and from the lower internal intercostal arteries. From below, the inferior phrenic arteries supply the diaphragm.The diaphragm drains blood into the brachiocephalic veins, azygos veins, and veins that drain into the inferior vena cava and left suprarenal vein.
Structure:
Variation The sternal portion of the muscle is sometimes wanting and more rarely defects occur in the lateral part of the central tendon or adjoining muscle fibers.
Structure:
Development The thoracic diaphragm develops during embryogenesis, beginning in the third week after fertilization with two processes known as transverse folding and longitudinal folding. The septum transversum, the primitive central tendon of the diaphragm, originates at the rostral pole of the embryo and is relocated during longitudinal folding to the ventral thoracic region. Transverse folding brings the body wall anteriorly to enclose the gut and body cavities. The pleuroperitoneal membrane and body wall myoblasts, from somatic lateral plate mesoderm, meet the septum transversum to close off the pericardio-peritoneal canals on either side of the presumptive esophagus, forming a barrier that separates the peritoneal and pleuropericardial cavities. Furthermore, dorsal mesenchyme surrounding the presumptive esophagus form the muscular crura of the diaphragm.
Structure:
Because the earliest element of the embryological diaphragm, the septum transversum, forms in the cervical region, the phrenic nerve that innervates the diaphragm originates from the cervical spinal cord (C3,4, and 5). As the septum transversum descends inferiorly, the phrenic nerve follows, accounting for its circuitous route from the upper cervical vertebrae, around the pericardium, finally to innervate the diaphragm.
Function:
The diaphragm is the main muscle of respiration and functions in breathing. During inhalation, the diaphragm contracts and moves in the inferior direction, enlarging the volume of the thoracic cavity and reducing intra-thoracic pressure (the external intercostal muscles also participate in this enlargement), forcing the lungs to expand. In other words, the diaphragm's movement downwards creates a partial vacuum in the thoracic cavity, which forces the lungs to expand to fill the void, drawing air in the process.
Function:
Cavity expansion happens in two extremes, along with intermediary forms. When the lower ribs are stabilized and the central tendon of the diaphragm is mobile, a contraction brings the insertion (central tendon) towards the origins and pushes the lower cavity towards the pelvis, allowing the thoracic cavity to expand downward. This is often called belly breathing. When the central tendon is stabilized and the lower ribs are mobile, a contraction lifts the origins (ribs) up towards the insertion (central tendon) which works in conjunction with other muscles to allow the ribs to slide and the thoracic cavity to expand laterally and upwards.
Function:
When the diaphragm relaxes (moves in the superior direction), air is exhaled by elastic recoil process of the lung and the tissues lining the thoracic cavity. Assisting this function with muscular effort (called forced exhalation) involves the internal intercostal muscles used in conjunction with the abdominal muscles, which act as an antagonist paired with the diaphragm's contraction. Diaphragm dysfunction is a well-known factor associated with various complications in patients, such as prolonged respiratory failure, difficulties in weaning from mechanical ventilation, extended hospitalization, increased morbidity, and mortality. Studies have reported that a thin diaphragm leads to greater lung compliance, which can contribute to respiratory failure. Furthermore, reduction in diaphragm thickness during the early stages of disease can serve as a prognostic marker in sepsis patients, COVID-19 patients.The diaphragm is also involved in non-respiratory functions. It helps to expel vomit, feces, and urine from the body by increasing intra-abdominal pressure, aids in childbirth, and prevents acid reflux by exerting pressure on the esophagus as it passes through the esophageal hiatus.
Function:
In some non-human animals, the diaphragm is not crucial for breathing; a cow, for instance, can survive fairly asymptomatically with diaphragmatic paralysis as long as no massive aerobic metabolic demands are made of it.
Clinical significance:
Paralysis If either the phrenic nerve, cervical spine or brainstem is damaged, this will sever the nervous supply to the diaphragm. The most common damage to the phrenic nerve is by bronchial cancer, which usually only affects one side of the diaphragm. Other causes include Guillain–Barré syndrome and systemic lupus erythematosus.
Clinical significance:
Herniation A hiatus hernia is a hernia common in adults in which parts of the lower esophagus or stomach that are normally in the abdomen pass/bulge abnormally through the diaphragm and are present in the thorax. Hernias are described as rolling, in which the hernia is beside the oesophagus, or sliding, in which the hernia directly involves the esophagus. These hernias are implicated in the development of reflux, as the different pressures between the thorax and abdomen normally act to keep pressure on the esophageal hiatus. With herniation, this pressure is no longer present, and the angle between the cardia of the stomach and the oesophagus disappear. Not all hiatus hernias cause symptoms however, although almost all people with Barrett's oesophagus or oesophagitis have a hiatus hernia.Hernias may also occur as a result of congenital malformation, a congenital diaphragmatic hernia. When the pleuroperitoneal membranes fail to fuse, the diaphragm does not act as an effective barrier between the abdomen and thorax. Herniation is usually of the left, and commonly through the posterior lumbocostal triangle, although rarely through the anterior foramen of Morgagni. The contents of the abdomen, including the intestines, may be present in the thorax, which may impact development of the growing lungs and lead to hypoplasia. This condition is present in 0.8 - 5/10,000 births. A large herniation has high mortality rate, and requires immediate surgical repair.
Clinical significance:
Imaging Due to its position separating the thorax and abdomen, fluid abnormally present in the thorax, or air abnormally present in the abdomen, may collect on one side of the diaphragm. An X-ray may reveal this. Pleural effusion, in which there is fluid abnormally present between the two pleurae of the lungs, is detected by an X-ray of the chest, showing fluid collecting in the angle between the ribs and diaphragm. An X-ray may also be used to reveal a pneumoperitoneum, in which there is gas in the abdomen.
Clinical significance:
An X-ray may also be used to check for herniation.
Significance in strength training:
The adoption of a deeper breathing pattern typically occurs during physical exercise in order to facilitate greater oxygen absorption. During this process the diaphragm more consistently adopts a lower position within the body's core. In addition to its primary role in breathing, the diaphragm also plays a secondary role in strengthening the posture of the core. This is especially evident during deep breathing where its generally lower position increases intra-abdominal pressure, which serves to strengthen the lumbar spine.
Significance in strength training:
The key to real core stabilization is to maintain the increased IAP while going through normal breathing cycles. [...] The diaphragm then performs its breathing function at a lower position to facilitate a higher IAP.Therefore, if a person's diaphragm position is lower in general, through deep breathing, then this assists the strengthening of their core during that period. This can be an aid in strength training and other forms of athletic endeavour. For this reason, taking a deep breath or adopting a deeper breathing pattern is typically recommended when lifting heavy weights.
Other animals:
The existence of a membrane separating the pharynx from the stomach can be traced widely among the chordates. Thus the model organism, the marine chordate lancelet, possesses an atriopore by which water exits the pharynx, which has been claimed (and disputed) to be homologous to structures in ascidians and hagfishes. The tunicate epicardium separates digestive organs from the pharynx and heart, but the anus returns to the upper compartment to discharge wastes through an outgoing siphon.
Other animals:
Thus the diaphragm emerges in the context of a body plan that separated an upper feeding compartment from a lower digestive tract, but the point at which it originates is a matter of definition. Structures in fish, amphibians, reptiles, and birds have been called diaphragms, but it has been argued that these structures are not homologous. For instance, the alligator diaphragmaticus muscle does not insert on the esophagus and does not affect pressure of the lower esophageal sphincter. The lungs are located in the abdominal compartment of amphibians and reptiles, so that contraction of the diaphragm expels air from the lungs rather than drawing it into them. In birds and mammals, lungs are located above the diaphragm. The presence of an exceptionally well-preserved fossil of Sinosauropteryx, with lungs located beneath the diaphragm as in crocodiles, has been used to argue that dinosaurs could not have sustained an active warm-blooded physiology, or that birds could not have evolved from dinosaurs. An explanation for this (put forward in 1905), is that lungs originated beneath the diaphragm, but as the demands for respiration increased in warm-blooded birds and mammals, natural selection came to favor the parallel evolution of the herniation of the lungs from the abdominal cavity in both lineages.However, birds do not have diaphragms. They do not breathe in the same way as mammals and do not rely on creating a negative pressure in the thoracic cavity, at least not to the same extent. They rely on a rocking motion of the keel of the sternum to create local areas of reduced pressure to supply thin, membranous airsacs cranially and caudally to the fixed-volume, non-expansive lungs. A complicated system of valves and air sacs cycles air constantly over the absorption surfaces of the lungs so allowing maximal efficiency of gaseous exchange. Thus, birds do not have the reciprocal tidal breathing flow of mammals. On careful dissection, around eight air sacs can be clearly seen. They extend quite far caudally into the abdomen. | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**Pecan log roll**
Pecan log roll:
A pecan log roll is a confectionery popularized by the roadside convenience store, Stuckey's.Pecan log rolls are described by the company's website as "fluffy, cherry-laced nougat wrapped in fresh caramel and pecans." | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
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