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The g is the respective gravitational pull on the object within a null-medium. R = v i 2 sin 2 θ i g {\displaystyle R={v_{i}^{2}\sin 2\theta _{i} \over g}} The height, h, is the greatest parabolic height said object reaches within its trajectory h = v i 2 sin 2 θ i 2 g {\displaystyle h={v_{i}^{2}\sin ^{2}\theta _{i} \over 2g}} ==== Angle of elevation ==== In terms of angle of elevation θ {\displaystyle \theta } and initial speed v {\displaystyle v} : v h = v cos θ , v v = v sin θ {\displaystyle v_{h}=v\cos \theta ,\quad v_{v}=v\sin \theta \;} giving the range as R = 2 v 2 cos ( θ ) sin ( θ ) / g = v 2 sin ( 2 θ ) / g . {\displaystyle R=2v^{2}\cos(\theta )\sin(\theta )/g=v^{2}\sin(2\theta )/g\,.} This equation can be rearranged to find the angle for a required range θ = 1 2 sin − 1 ( g R v 2 ) {\displaystyle \theta ={\frac {1}{2}}\sin ^{-1}\left({\frac {gR}{v^{2}}}\right)} (Equation II: angle of projectile launch) Note that the sine function is such that there are two solutions for θ {\displaystyle \theta } for a given range d h {\displaystyle d_{h}} . The angle θ {\displaystyle \theta } giving the maximum range can be found by considering the derivative or R {\displaystyle R} with respect to θ {\displaystyle \theta } and setting it to zero. d R d θ = 2 v 2 g cos ( 2 θ ) = 0 {\displaystyle {\mathrm {d} R \over \mathrm {d} \theta }={2v^{2} \over g}\cos(2\theta )=0} which has a nontrivial solution at 2 θ = π / 2 = 90 ∘ {\displaystyle 2\theta =\pi /2=90^{\circ }} , or θ = 45 ∘ {\displaystyle \theta =45^{\circ
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{
"page_id": 200115,
"source": null,
"title": "Trajectory"
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}} . The maximum range is then R max = v 2 / g {\displaystyle R_{\max }=v^{2}/g\,} . At this angle sin ( π / 2 ) = 1 {\displaystyle \sin(\pi /2)=1} , so the maximum height obtained is v 2 4 g {\displaystyle {v^{2} \over 4g}} . To find the angle giving the maximum height for a given speed calculate the derivative of the maximum height H = v 2 sin 2 ( θ ) / ( 2 g ) {\displaystyle H=v^{2}\sin ^{2}(\theta )/(2g)} with respect to θ {\displaystyle \theta } , that is d H d θ = v 2 2 cos ( θ ) sin ( θ ) / ( 2 g ) {\displaystyle {\mathrm {d} H \over \mathrm {d} \theta }=v^{2}2\cos(\theta )\sin(\theta )/(2g)} which is zero when θ = π / 2 = 90 ∘ {\displaystyle \theta =\pi /2=90^{\circ }} . So the maximum height H m a x = v 2 2 g {\displaystyle H_{\mathrm {max} }={v^{2} \over 2g}} is obtained when the projectile is fired straight up. === Orbiting objects === If instead of a uniform downwards gravitational force we consider two bodies orbiting with the mutual gravitation between them, we obtain Kepler's laws of planetary motion. The derivation of these was one of the major works of Isaac Newton and provided much of the motivation for the development of differential calculus. == Catching balls == If a projectile, such as a baseball or cricket ball, travels in a parabolic path, with negligible air resistance, and if a player is positioned so as to catch it as it descends, he sees its angle of elevation increasing continuously throughout its flight. The tangent of the angle of elevation is proportional to the time since the ball was sent into the air,
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"page_id": 200115,
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usually by being struck with a bat. Even when the ball is really descending, near the end of its flight, its angle of elevation seen by the player continues to increase. The player therefore sees it as if it were ascending vertically at constant speed. Finding the place from which the ball appears to rise steadily helps the player to position himself correctly to make the catch. If he is too close to the batsman who has hit the ball, it will appear to rise at an accelerating rate. If he is too far from the batsman, it will appear to slow rapidly, and then to descend. == Notes == == See also == Aft-crossing trajectory Displacement (geometry) Galilean invariance Orbit (dynamics) Orbit (group theory) Orbital trajectory Phugoid Planetary orbit Porkchop plot Projectile motion Range of a projectile Rigid body World line == References == == External links == Projectile Motion Flash Applet Archived 14 September 2008 at the Wayback Machine:) Trajectory calculator An interactive simulation on projectile motion Projectile Lab, JavaScript trajectory simulator Parabolic Projectile Motion: Shooting a Harmless Tranquilizer Dart at a Falling Monkey by Roberto Castilla-Meléndez, Roxana Ramírez-Herrera, and José Luis Gómez-Muñoz, The Wolfram Demonstrations Project. Trajectory, ScienceWorld. Java projectile-motion simulation, with first-order air resistance. Archived 3 July 2012 at the Wayback Machine Java projectile-motion simulation; targeting solutions, parabola of safety.
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{
"page_id": 200115,
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"title": "Trajectory"
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In chemistry, cryptands are a family of synthetic, bicyclic and polycyclic, multidentate ligands for a variety of cations. The Nobel Prize for Chemistry in 1987 was given to Donald J. Cram, Jean-Marie Lehn, and Charles J. Pedersen for their efforts in discovering and determining uses of cryptands and crown ethers, thus launching the now flourishing field of supramolecular chemistry. The term cryptand implies that this ligand binds substrates in a crypt, interring the guest as in a burial. These molecules are three-dimensional analogues of crown ethers but are more selective and strong as complexes for the guest ions. The resulting complexes are lipophilic. == Structure == The most common and most important cryptand is N[CH2CH2OCH2CH2OCH2CH2]3N; the systematic IUPAC name for this compound is 1,10-diaza-4,7,13,16,21,24-hexaoxabicyclo[8.8.8]hexacosane. This compound is termed [2.2.2]cryptand, where the numbers indicate the number of ether oxygen atoms (and hence binding sites) in each of the three bridges between the amine nitrogen caps. Many cryptands are commercially available under the tradename Kryptofix. All-amine cryptands exhibit particularly high affinity for alkali metal cations, which has allowed the isolation of salts of K−. == Properties == === Cation binding === The three-dimensional interior cavity of a cryptand provides a binding site – or host – for "guest" ions. The complex between the cationic guest and the cryptand is called a cryptate. Cryptands form complexes with many "hard cations" including NH+4, lanthanoids, alkali metals, and alkaline earth metals. In contrast to crown ethers, cryptands bind the guest ions using both nitrogen and oxygen donors. This three-dimensional encapsulation mode confers some size-selectivity, enabling discrimination among alkali metal cations (e.g. Na+ vs. K+). Some cryptands are luminescent. === Anion binding === Polyamine-based cryptands can be converted to polyammonium cages, which exhibit high affinities for anions. == Laboratory uses == Cryptands enjoy some commercial applications
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{
"page_id": 1904052,
"source": null,
"title": "Cryptand"
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(e.g. in homogenous-time-resolved-fluorescence, HTRF, technologies using Eu3+ as central ion). More importantly, they are reagents for the synthesis of inorganic and organometallic salts. Although more expensive and more difficult to prepare than crown ethers, cryptands bind alkali metals more strongly. They are especially used to isolate salts of highly basic anions. They convert solvated alkali metal cations into lipophilic cations, thereby conferring solubility in organic solvents to the resulting salts. Referring to achievements that have been recognized in textbooks, cryptands enabled the synthesis of the alkalides and electrides. For example, addition of 2,2,2-cryptand to a solution of sodium in ammonia affords the salt [Na(2,2,2-crypt)]+e−, isolated a blue-black paramagnetic solid. Cryptands have also been used in the crystallization of Zintl ions such as Sn4−9. Although rarely practical, cryptands can serve as phase transfer catalysts since their cationic complexes are lipophilic. == See also == Tris(2-(2-methoxyethoxy)ethyl)amine, an acyclic amine-polyether ligand that is less expensive than cryptands Clathrate, a compound that encapsulates ions or molecules Clathrochelate, a ligand that encapsulated metal ions Cryptophane, a family of organic compounds that encapsulates other molecules Cyclodextrin, a family of organic compounds consists of ring of glucose subunits, also used for host-guest chemistry == References == == General reading == IUPAC, Compendium of Chemical Terminology, 2nd ed. (the "Gold Book") (1997). Online corrected version: (2006–) "cryptand". doi:10.1351/goldbook.C01426 Lee, J.D. (1991). Concise Inorganic Chemistry (4th ed.). New York: Chapman & Hall. pp. 306–308 & 353. ISBN 0-412-40290-4. Krakowiak, K. E.; Bradshaw, J. S.; An, H.-Y.; Izatt, R. M. (1993). "Simple methods for the preparation of cryptands". Pure Appl. Chem. 65 (3): 511–514. doi:10.1351/pac199365030511.
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{
"page_id": 1904052,
"source": null,
"title": "Cryptand"
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Trans-prenyltransferase may refer to: All-trans-octaprenyl-diphosphate synthase, an enzyme All-trans-decaprenyl-diphosphate synthase, an enzyme
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{
"page_id": 38866356,
"source": null,
"title": "Trans-prenyltransferase"
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In biology, dactyly is the arrangement of digits (fingers and toes) on the hands, feet, or sometimes wings of a tetrapod animal. The term is derived from the Greek word δακτυλος (dáktylos) meaning "finger." Sometimes the suffix "-dactylia" is used. The derived adjectives end with "-dactyl" or "-dactylous." == As a normal feature == === Pentadactyly === Pentadactyly (from Greek πέντε pénte "five") is the condition of having five digits on each limb. It is traditionally believed that all living tetrapods are descended from an ancestor with a pentadactyl limb, although many species have now lost or transformed some or all of their digits by the process of evolution. However, this viewpoint was challenged by Stephen Jay Gould in his 1991 essay "Eight (or Fewer) Little Piggies," where he pointed out polydactyly in early tetrapods and described the specializations of digit reduction. Despite the individual variations listed below, the relationship is to the original five-digit model. In reptiles, the limbs are pentadactylous. Dogs have tetradactylous paws but the dewclaw makes them pentadactyls. Cats also have dewclaws on their front limbs but not their hind limbs, making them both pentadactyls and tetradactyls. === Tetradactyly === Tetradactyly (from Greek τετρα tetra 'four') is the condition of having four digits on a limb, as in many birds, amphibians, and theropod dinosaurs. === Tridactyly === Tridactyly (from Greek τρία tría 'three') is the condition of having three digits on a limb, as in the rhinoceros and ancestors of the horse such as Protohippus and Hipparion. These all belong to the Perissodactyla. Some birds also have three toes, including emus, bustards, and quail. === Didactyly === Didactyly (from Greek δι- di- 'two') or bidactyly is the condition of having two digits on each limb, as in the Hypertragulidae and two-toed sloth, Choloepus didactylus. In humans
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"page_id": 265656,
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this name is used for an abnormality in which the middle digits are missing, leaving only the thumb and fifth finger, or big and little toes. Cloven-hoofed mammals (such as deer, sheep and cattle – Artiodactyla) have only two digits, as do ostriches. === Monodactyly === Monodactyly (from Greek μόνος monos- 'one') is the condition of having a single digit on a limb, as in modern horses and other equidae (though one study suggests that the frog might be composed of remnants of digits II and IV, rendering horses as not truly monodactyl) as well as sthenurine kangaroos. Functional monodactyly, where the weight is supported on only one of multiple toes, can also occur, as in the theropod dinosaur Vespersaurus. The pterosaur Nyctosaurus retained only the wing finger on the forelimb, rendering it also partially monodactyl. == As a congenital defect == Among humans, the term "five-fingered hand" is sometimes used to mean the abnormality of having five fingers, none of which is a thumb. === Syndactyly === Syndactyly (from Greek συν- syn 'together') is a condition where two or more digits are fused together. It occurs normally in some mammals, such as the siamang and most diprotodontid marsupials such as kangaroos. It occurs as an unusual condition in humans. === Polydactyly === Polydactyly (from Greek πολυ- poly- 'many') is when a limb has more than the usual number of digits. This can be: As a result of congenital abnormality in a normally pentadactyl animal. Polydactyly is very common among domestic cats. For more information, see polydactyly. Polydactyly in early tetrapod aquatic animals, such as in Acanthostega gunnari (Jarvik 1952), one of an increasing number of genera of stem-tetrapods known from the Upper Devonian, which are providing insights into the appearance of tetrapods and the origin of limbs with digits.
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It also occurs secondarily in some later tetrapods, such as ichthyosaurs. The use of a term normally reserved for congenital defects reflects that it was regarded as an anomaly at the time, as it was believed that all modern tetrapods have either five digits or ancestors that did. === Oligodactyly === Oligodactyly (from Greek ὀλιγο- oligo- 'few') is having too few digits when not caused by an amputation. It is sometimes incorrectly called hypodactyly or confused with aphalangia, the absence of the phalanx bone on one or (commonly) more digits. When all the digits on a hand or foot are absent, it is referred to as adactyly. ==== Ectrodactyly ==== Ectrodactyly, also known as split-hand malformation, is the congenital absence of one or more central digits of the hands and feet. Consequently, it is a form of oligodactyly. News anchor Bree Walker is probably the best-known person with this condition, which affects about one in 91,000 people. It is conspicuously more common in the Vadoma in Zimbabwe. === Clinodactyly === Clinodactyly is a medical term describing the curvature of a digit (a finger or toe) in the plane of the palm, most commonly the fifth finger (the "little finger") towards the adjacent fourth finger (the "ring finger"). It is a fairly common isolated anomaly which often goes unnoticed, but also occurs in combination with other abnormalities in certain genetic syndromes, such as Down syndrome, Turner syndrome and Cornelia de Lange syndrome. == In birds == === Anisodactyly === Anisodactyly is the most common arrangement of digits in birds, with three toes forward and one back. This is common in songbirds and other perching birds, as well as hunting birds such as eagles, hawks, and falcons. This arrangement of digits helps with perching and/or climbing and clinging. This occurs in Passeriformes,
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Columbiformes, Falconiformes, Accipitriformes, Galliformes and a majority of other birds. === Syndactyly === Syndactyly, as it occurs in birds, is like anisodactyly, except that the third and fourth toes (the outer and middle forward-pointing toes), or three toes, are fused together almost to their claws, as in the belted kingfisher (Megaceryle alcyon). This is often found in Picocoraciae, though rollers, ground rollers, and Piciformes (who are zygodactyl) are exceptions.: 37 === Zygodactyly === Zygodactyly (from Greek ζυγος, even-numbered) is an arrangement of digits in birds and chameleons, with two toes facing forward (digits 2 and 3) and two back (digits 1 and 4). This arrangement is most common in arboreal species, particularly those that climb tree trunks or clamber through foliage. Zygodactyly occurs in the parrots, woodpeckers (including flickers), cuckoos (including roadrunners), and some owls. Zygodactyl tracks have been found dating to 120–110 million years ago (early Cretaceous), 50 million years before the first identified zygodactyl fossils. All Psittaciformes, Cuculiformes, the majority of Piciformes and the osprey are zygodactyl. === Heterodactyly === Heterodactyly is like zygodactyly, except that digits 3 and 4 point forward and digits 1 and 2 point back. This is found only in trogons, though the enantiornithean Dalingheornis might also have had this arrangement. === Pamprodactyly === Pamprodactyly is an arrangement in which all four toes point forward, outer toes (toe 1 and sometimes 4) often if not regularly reversible. It is a characteristic of swifts (Apodidae) and mousebirds (Coliiformes).: 37–38 == Chameleons == The feet of chameleons are organized into bundles of a group of two and a group of three digits which oppose one another to grasp branches in a pincer-like arrangement. This condition has been called zygodactyly or didactyly, but the specific arrangement in chameleons does not fit either definition. The feet of the
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front limbs in chameleons, for instance, are organized into a medial bundle of digits 1, 2 and 3, and a lateral bundle of digits 4 and 5, while the feet of the hind limbs are organized into a medial bundle of digits 1 and 2, and a lateral bundle of digits 3, 4 and 5. On the other hand, zygodactyly involves digits 1 and 4 opposing digits 2 and 3, which is an arrangement that chameleons do not exhibit in either front or hind limbs. == Aquatic tetrapods == In many secondarily aquatic vertebrates, the non-bony tissues of the forelimbs and/or hindlimbs are fused into a single flipper. Some remnant of each digit generally remains under the soft tissue of the flipper, though digit reduction gradually occurs such as in baleen whales (mysticeti). Marine mammals evolving flippers represents a classic example of convergent evolution, and by some analyses, parallel evolution. Full webbing of the digits in the manus and/or pes is present in a number of aquatic tetrapods. Such animals include marine mammals (cetaceans, sirenians, and pinnipeds), marine reptiles (modern sea turtles and extinct ichthyosaurs, mosasaurs, plesiosaurs, metriorhynchids), and flightless aquatic birds such as penguins. Hyperphalangy, or an increase in the number of phalanges beyond ancestral mammal and reptile conditions, is present in modern cetaceans and extinct marine reptiles. == Schizodactyly == Schizodactyly is a primate term for grasping and clinging with the second and third digit, instead of the thumb and second digit. == See also == Artiodactyl – even-toed ungulates, clade Cetartiodactyla Perissodactyl – odd-toed ungulates == References == == External links == Coates, Michael (25 April 2005). "Why do most species have five digits on their hands and feet?". Scientific American. Retrieved 2009-07-05.
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"page_id": 265656,
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The term total analysis system (TAS) describes a device that combines and automates all necessary steps for the chemical analysis of a sample (e.g., sampling, sample transport, filtration, dilution, chemical reactions, separation, and detection). Most current total analysis systems are "micro" total analysis systems which utilize the principles of microfluidics. Total analysis systems are designed to shrink the processes carried out in a laboratory to a chip-sized lab-on-a-chip. Due to this, it can be more cost-effective to carry out complex tests when considering chip technologies, sample sizes, and analysis time. Total analysis systems can also reduce the exposure of toxic chemicals for lab personnel. This technology can also be used in point-of-care testing or point-of-use diagnostics, which do not require skilled technicians. == See also == Microelectromechanical systems Microfluidics Bio-MEMS Lab-on-a-chip == References ==
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{
"page_id": 921018,
"source": null,
"title": "Total analysis system"
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Bimetal refers to an object that is composed of two separate metals joined together. Instead of being a mixture of two or more metals, like alloys, bimetallic objects consist of layers of different metals. Trimetal and tetrametal refer to objects composed of three and four separate metals respectively. A bimetal bar is usually made of brass and iron. Bimetallic strips and disks, which convert a temperature change into mechanical displacement, are the most recognized bimetallic objects due to their name. However, there are other common bimetallic objects. For example, tin cans consist of steel covered with tin. The tin prevents the can from rusting. To cut costs and prevent people from melting them down for their metal, coins are often composed of a cheap metal covered with a more expensive metal. For example, the United States penny was changed from 95% copper to 95% zinc, with a thin copper plating to retain its appearance. A common type of trimetallic object (before the all-aluminium can) was a tin-plated steel can with an aluminum lid with a pull tab. Making the lid out of aluminum allowed it to be pulled off by hand instead of using a can opener, but these cans proved difficult to recycle owing to their mix of metals. Blades for bandsaws and reciprocating saws are often made with bimetal construction. The teeth, made of high-speed steel, are bonded (by various methods, for example, electron beam welding or laser beam welding) to the softer high-carbon steel base. Such construction makes for blades with a better combination of cutting speed and durability than shown by non-bimetal blades, because the advantages and disadvantages of each of the metals are applied in the best locations: the teeth are harder (and thus cut better), but therefore also brittler; meanwhile, the body area of
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{
"page_id": 593338,
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the band is softer (which would make for poorer teeth), but also less brittle, and thus more resistant to cracking and breaking (which is desirable in the body area). == See also == Bimetallic strip Bimetallism Bi-metallic coin Thermocouple (electric) Copper-clad steel == References == == Further reading == Thermal imaging with tapping mode using a bimetal oscillator formed at the end of a cantilever Bimetal: Definition, Properties, and Applications Kanthal Thermostatic Bimetal Guide.pdf How Thermostatic Bimetal Works
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"page_id": 593338,
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"title": "Bimetal"
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This is a list of types of formally designated forests, as institutionalized around the world. It is organized in three sublists: by forest ownership, protection status, and designated use. == By ownership == Church forests of Ethiopia - protected sacred forests around rural churches Community forest Community forests in England County forest Crown land Municipal forest National forest National forest (Brazil) - a type of sustainable use protected area The National Forest (England) - a government-supported, "environmental project in central England" National forest (France) - a forest that is owned by the French state, originating with the Edict of Moulins of 1566 National forest (United States) - classification of Federal lands in the United States National reserve - legal designation in the United States, beginning in 1978 Private forest Corporate forest Private nonindustrial forest land Private landowner assistance program - a class of U.S. government assistance program for maintaining, developing, improving and protecting wildlife Private reserve Private forest reserve Private timber reserve (Tasmania) Private nature reserve Provincial forest - administered or protected by an agency of a province; varies by jurisdiction Provincial forests (Manitoba) Royal forest - an area of land with varying meanings; not necessarily densely wooded State forest - administered or protected by an agency of a state; varies by jurisdiction Tribal forest - owned, controlled, and/or utilized by a (formally recognized) Indigenous or tribal group == By protection status == Ancient woodland - formal designation used in the United Kingdom Ancient semi-natural woodland (ASNW) - composed of native tree species not obviously planted Bannwald - a protected forest area in parts of Germany and Austria Biosphere reserve - as designated by UNESCO Biological reserve Conservation reserve - used in the United States' Conservation Reserve Program Forest circle - an administrative area including protected or resource-managed forests, used
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{
"page_id": 35655100,
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"title": "List of types of formally designated forests"
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in India, Pakistan and Bangladesh Forest division - a non-overlapping subdivision of a forest circle, used in India, Pakistan and Bangladesh Forest park (The Gambia), as in Dobo Forest Park, Faba Forest Park, Finto Manereg Forest Park, etc. Forest preserve, formal dedication for state-owned lands within the constitutionally designated Adirondack and Catskill Parks of the U.S. state of New York, required to be kept forever wild. Forest protected area - formal designation of the International Union for Conservation of Nature and the World Commission on Protected Areas Forest range - a non-overlapping subdivision of a forest division, used in India, Pakistan and Bangladesh Forest reserve or preserve Recreational forest reserve, e.g. the Recreational Forest Reserve of Fontinhas, Azores High-biodiversity wilderness area - an International Union for Conservation of Nature classification High conservation value area - developed by the Forest Stewardship Council as a means of defining regions with a specific environmental, socioeconomic, biodiversity or landscape value for use within forestry management certification systems High conservation value forest - a FSC designation for forests meeting criteria specified in its "Principles and Criteria of Forest Stewardship" Intact forest landscape - NGO-developed term used in forest monitoring Old-growth forest - in Australia, formal protection category in the Regional Forest Agreement Private natural heritage reserve - designation used in Brazil Protected forest - used in Cambodia and India Protected landscape - used in the Czech Republic Reserve forest - used to designate protected forest areas in British India; used today in Bangladesh, India, Kazakhstan and Pakistan to refer to forests accorded a special degree of protection Reserved forests and protected forests of India Protected and reserved forests of Pakistan Sacred grove - protected in Ghana, Nigeria and possibly elsewhere Sacred groves of India Schonwald, a type of formally protected forest in Baden-Württemberg, Germany, in
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{
"page_id": 35655100,
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"title": "List of types of formally designated forests"
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which economic usage of the forest is permitted under certain restrictions Wild forest, formal designation within the New York Forest Preserve Wilderness forest Wildlife forest Wildlife management area Wildlife reserve Wildlife sanctuaries of India World Heritage Forest - formally recognized for special biophysical or cultural significance; administered by UNESCO == By designated use == Dehesa - lands utilizing a particular agrosylvopastoral system in Spain and Portugal Demonstration forest Experimental forest - formal designation used by the United States Forest Service Intensive monitoring site - formal designation used by the United States Forest Service Long-term ecological research site Model forest - formal designation used by the Food and Agriculture Organization and the International Model Forest Network Private nonindustrial forest land - small, family owned, and timber-producing forest lands Production forest Protection forest - forests that mitigate or prevent the impact of a natural hazard; designation in France, Germany, Italy, Switzerland (Schutzwald) and elsewhere in Europe, particularly in mountainous areas (e.g. as a protection against avalanches) Research natural area - formal designation used by the United States Forest Service Teaching forest == See also == == References == == External links == UNESCO World Heritage Forest Programme
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"page_id": 35655100,
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Creosote is a category of carbonaceous chemicals formed by the distillation of various tars and pyrolysis of plant-derived material, such as wood, or fossil fuel. They are typically used as preservatives or antiseptics. Some creosote types were used historically as a treatment for components of seagoing and outdoor wood structures to prevent rot (e.g., bridgework and railroad ties, see image). Samples may be found commonly inside chimney flues, where the coal or wood burns under variable conditions, producing soot and tarry smoke. Creosotes are the principal chemicals responsible for the stability, scent, and flavor characteristic of smoked meat; the name is derived from Greek κρέας (kreas) 'meat' and σωτήρ (sōtēr) 'preserver'. The two main kinds recognized in industry are coal-tar creosote and wood-tar creosote. The coal-tar variety, having stronger and more toxic properties, has chiefly been used as a preservative for wood; coal-tar creosote was also formerly used as an escharotic, to burn malignant skin tissue, and in dentistry, to prevent necrosis, before its carcinogenic properties became known. The wood-tar variety has been used for meat preservation, ship treatment, and such medical purposes as an anaesthetic, antiseptic, astringent, expectorant, and laxative, though these have mostly been replaced by modern formulations. Varieties of creosote have also been made from both oil shale and petroleum, and are known as oil-tar creosote when derived from oil tar, and as water-gas-tar creosote when derived from the tar of water gas. Creosote also has been made from pre-coal formations such as lignite, yielding lignite-tar creosote, and peat, yielding peat-tar creosote. == Creosote oils == The term creosote has a broad range of definitions depending on the origin of the coal tar oil and end-use of the material. With respect to wood preservatives, the United States Environmental Protection Agency (EPA) considers the term creosote to mean
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{
"page_id": 69053,
"source": null,
"title": "Creosote"
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a pesticide for use as a wood preservative meeting the American Wood Protection Association (AWPA) Standards P1/P13 and P2. The AWPA Standards require that creosote "shall be a pure coal tar product derived entirely from tar produced by the carbonization of bituminous coal." Currently, all creosote-treated wood products—foundation and marine pilings, lumber, posts, railroad ties, timbers, and utility poles—are manufactured using this type of wood preservative. The manufacturing process can only be a pressure process under the supervision of a licensed applicator certified by the State Departments of Agriculture. No brush-on, spray, or non-pressure uses of creosote are allowed, as specified by the EPA-approved label for the use of creosote. The use of creosote according to the AWPA Standards does not allow for mixing with other types of "creosote type" materials—such as lignite-tar creosote, oil-tar creosote, peat-tar creosote, water-gas-tar creosote, or wood-tar creosote. The AWPA Standard P3 does however, allow blending of a high-boiling petroleum oil meeting the AWPA Standard P4. The information that follows describing the other various types of creosote materials and its uses should be considered as primarily being of only historical value. This history is important, because it traces the origin of these different materials used during the 19th and early 20th centuries. Furthermore, it must be considered that these other types of creosotes – lignite-tar, wood-tar, water-gas-tar, etc. – are not currently being manufactured and have either been replaced with more-economical materials, or replaced by products that are more efficacious or safer. For some part of their history, coal-tar creosote and wood-tar creosote were thought to have been equivalent substances—albeit of distinct origins—accounting for their common name; the two were determined only later to be chemically different. All types of creosote are composed of phenol derivatives and share some quantity of monosubstituted phenols, but these
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{
"page_id": 69053,
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"title": "Creosote"
}
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are not the only active element of creosote. For their useful effects, coal-tar creosote relies on the presence of naphthalenes and anthracenes, while wood-tar creosote relies on the presence of methyl ethers of phenol. Otherwise, either type of tar would dissolve in water. Creosote was first discovered in its wood-tar form in 1832, by Carl Reichenbach, when he found it both in the tar and in pyroligneous acids obtained by a dry distillation of beechwood. Because pyroligneous acid was known as an antiseptic and meat preservative, Reichenbach conducted experiments by dipping meat in a dilute solution of distilled creosote. He found that the meat was dried without undergoing putrefaction and had attained a smoky flavor. This led him to reason that creosote was the antiseptic component contained in smoke, and he further argued that the creosote he had found in wood tar was also in coal tar, as well as amber tar and animal tar, in the same abundance as in wood tar. Soon afterward, in 1834, Friedrich Ferdinand Runge discovered carbolic acid (phenol) in coal-tar, and Auguste Laurent obtained it from "phenylhydrate", which was soon determined to be the same compound. There was no clear view on the relationship between carbolic acid and creosote; Runge described it as having similar caustic and antiseptic properties, but noted that it was different, in that it was an acid and formed salts. Nonetheless, Reichenbach argued that creosote was also the active element, as it was in pyroligneous acid. Despite evidence to the contrary, his view held sway with most chemists, and it became commonly accepted wisdom that creosote, carbolic acid, and phenylhydrate were identical substances, with different degrees of purity. Carbolic acid was soon commonly sold under the name "creosote", and the scarcity of wood-tar creosote in some places led chemists to
|
{
"page_id": 69053,
"source": null,
"title": "Creosote"
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believe that it was the same substance as that described by Reichenbach. In the 1840s, Eugen Freiherr von Gorup-Besanez, after realizing that two samples of substances labelled as creosote were different, started a series of investigations to determine the chemical nature of carbolic acid, leading to a conclusion that it more resembled chlorinated quinones and must have been a different, entirely unrelated substance. Independently, there were investigations into the chemical nature of creosote. A study by F.K. Völkel revealed that the smell of purified creosote resembled that of guaiacol, and later studies by Heinrich Hlasiwetz identified a substance common to guaiacum and creosote that he called creosol, and he determined that creosote contained a mixture of creosol and guaiacol. Later investigations by Gorup-Besanez, A.E. Hoffmann, and Siegfried Marasse showed that wood-tar creosote also contained phenols, giving it a feature in common with coal-tar creosote. Historically, coal-tar creosote has been distinguished from what was thought of as creosote proper—the original substance of Reichenbach's discovery—and it has been referred to specifically as "creosote oil". But, because creosote from coal-tar and wood-tar are obtained from a similar process and have some common uses, they have also been placed in the same class of substances, with the terms "creosote" or "creosote oil" referring to either product. === Wood-tar creosote === Wood-tar creosote is a colourless to yellowish greasy liquid with a smoky odor, produces a sooty flame when burned, and has a burned taste. It is non-buoyant in water, with a specific gravity of 1.037 to 1.087, retains fluidity at a very low temperature, and boils at 205-225 °C. In its purest form, it is transparent. Dissolution in water requires up to 200 times the amount of water as the base creosote. This creosote is a combination of natural phenols: primarily guaiacol and creosol
|
{
"page_id": 69053,
"source": null,
"title": "Creosote"
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(4-methylguaiacol), which typically constitutes 50% of the oil; second in prevalence are cresol and xylenol; the rest being a combination of monophenols and polyphenols. The simple phenols are not the only active element in wood-tar creosote. In solution, they coagulate albumin, which is a water-soluble protein found in meat, so they serve as a preserving agent, but also cause denaturation. Most of the phenols in the creosote are methoxy derivatives: they contain the methoxy group (−O−CH3) linked to the benzene nucleus. The high level of methyl derivates created from the action of heat on wood (also apparent in the methyl alcohol produced through distillation) make wood-tar creosote substantially different from coal-tar creosote. Guaiacol is a methyl ether of pyrocatechin, while creosol is a methyl ether of methyl-pyrocatechin, the next homolog of pyrocatechin. Methyl ethers differ from simple phenols in being less hydrophilic, caustic, and poisonous. This allows meat to be successfully preserved without tissue denaturation, and allows creosote to be used as a medical ointment. Because wood-tar creosote is used for its guaiacol and creosol content, it is generally derived from beechwood rather than other woods, since it distills with a higher proportion of those chemicals to other phenolics. The creosote can be obtained by distilling the wood tar and treating the fraction heavier than water with a sodium hydroxide solution. The alkaline solution is then separated from the insoluble oily layer, boiled in contact with air to reduce impurities, and decomposed by diluted sulfuric acid. This produces a crude creosote, which is purified by re-solution in alkali, re-precipitation with acid, then redistilled with the fraction passing over between 200° and 225° constituting the purified creosote. When ferric chloride is added to a dilute solution, it will turn green: a characteristic of ortho-oxy derivatives of benzene. It dissolves in sulfuric
|
{
"page_id": 69053,
"source": null,
"title": "Creosote"
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acid to a red liquid, which slowly changes to purple-violet. Shaken with hydrochloric acid in the absence of air, it becomes red, the color changing in the presence of air to dark brown or black. In preparation of food by smoking, guaiacol contributes mainly to the smoky taste, while the dimethyl ether of pyrogallol, syringol, is the main chemical responsible for the smoky aroma. ==== Historical uses ==== ===== Industrial ===== Soon after it was discovered and recognized as the principle of meat smoking, wood-tar creosote became used as a replacement for the process. Several methods were used to apply the creosote. One was to dip the meat in pyroligneous acid or a water of diluted creosote, as Reichenbach did, or brush it over with them, and within one hour the meat would have the same quality of that of traditionally smoked preparations. Sometimes the creosote was diluted in vinegar rather than water, as vinegar was also used as a preservative. Another was to place the meat in a closed box, and place with it a few drops of creosote in a small bottle. Because of the volatility of the creosote, the atmosphere was filled with a vapour containing it, and it would cover the flesh. The application of wood tar to seagoing vessels was practiced through the 18th century and early 19th century, before the creosote was isolated as a compound. Wood-tar creosote was found not to be as effective in wood treatments, because it was harder to infuse the creosote into the wood cells, but still experiments were done, including by many governments, because it proved to be less expensive on the market. ===== Medical ===== Even before creosote as a chemical compound was discovered, it was the chief active component of medicinal remedies in different cultures around
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{
"page_id": 69053,
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the world. In antiquity, pitches and resins were used commonly as medicines. Pliny mentions a variety of tar-like substances being used as medicine, including cedria and pissinum. Cedria was the pitch and resin of the cedar tree, being equivalent to the oil of tar and pyroligneous acid which are used in the first stage of distilling creosote. He recommends cedria to ease the pain in a toothache, as an injection in the ear in case of hardness of hearing, to kill parasitic worms, as a preventive for infusion, as a treatment for phthiriasis and porrigo, as an antidote for the poison of the sea hare, as a liniment for elephantiasis, and as an ointment to treat ulcers both on the skin and in the lungs. He further speaks of cedria being used as the embalming agent for preparing mummies. Pissinum was a tar water that was made by boiling cedria, spreading wool fleeces over the vessels to catch the steam, and then wringing them out. The Pharmacopée de Lyon, published in 1778, says that cedar tree oil is believed to cure vomiting and help medicate tumors and ulcers. Physicians contemporary to the discovery of creosote recommended ointments and pills made from tar or pitch to treat skin diseases. Tar water had been used as a folk remedy since the Middle Ages to treat affections like dyspepsia. Bishop Berkeley wrote several works on the medical virtues of tar water, including a philosophical work in 1744 titled Siris: a chain of philosophical reflexions and inquiries concerning the virtues of tar water, and divers other subjects connected together and arising one from another, and a poem where he praised its virtues. Pyroligneous acid was also used at the time in a medicinal water called Aqua Binelli (Binelli's water), a compound which its inventor,
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{
"page_id": 69053,
"source": null,
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the Italian Fedele Binelli, claimed to have hemostatic properties in his research published in 1797. These claims have since been disproven. Given this history, and the antiseptic properties known to creosote, it became popular among physicians in the 19th century. A dilution of creosote in water was sold in pharmacies as Aqua creosoti, as suggested by the previous use of pyroligneous acid. It was prescribed to quell the irritability of the stomach and bowels and detoxify, treat ulcers and abscesses, neutralize bad odors, and stimulate the mucous tissues of the mouth and throat. Creosote in general was listed as an irritant, styptic, antiseptic, narcotic, and diuretic, and in small doses when taken internally as a sedative and anaesthetic. It was used to treat ulcers, and as a way to sterilize the tooth and deaden the pain in case of a tooth-ache. Creosote was suggested as a treatment for tuberculosis by Reichenbach as early as 1833. Following Reichenbach, it was argued for by John Elliotson and Sir John Rose Cormack. Elliotson, inspired by the use of creosote to arrest vomiting during an outbreak of cholera, suggested its use for tuberculosis through inhalation. He also suggested it for epilepsy, neuralgia, diabetes, and chronic glanders. The idea of using it for tuberculosis failed to be accepted. Use for this purpose was dropped, until the idea was revived in 1876 by British doctor G. Anderson Imlay, who suggested it be applied locally by spray to the bronchial mucous membrane. This was followed up in 1877 when it was argued for in a clinical paper by Charles Bouchard and Henri Gimbert. Germ theory had been established by Pasteur in 1860, and Bouchard, arguing that a bacillus was responsible for the disease, sought to rehabilitate creosote for its use as an antiseptic to treat it. He
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{
"page_id": 69053,
"source": null,
"title": "Creosote"
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began a series of trials with Gimbert to convince the scientific community, and claimed a promising cure rate. A number of publications in Germany confirmed his results in the following years. Later, a period of experimentation with different techniques and chemicals using creosote in treating tuberculosis lasted until about 1910, when radiation therapy seemed more promising. Guaiacol, instead of a full creosote solution, was suggested by Hermann Sahli in 1887. He argued it had the active chemical of creosote and had the advantage of being of definite composition and having a less unpleasant taste and odor. A number of solutions of both creosote and guaiacol appeared on the market, such as phosphotal and guaicophosphal, phosphites of creosote and guaiacol; eosot and geosot, valerinates of creosote and guaicol; phosot and taphosot, phosphate and tannophospate of creosote; and creosotal and tanosal, tannates of creosote. Creosote and eucalyptus oil were also a remedy used together, administered through a vaporizor and inhaler. Since then, more effective and safer treatments for tuberculosis have been developed. In the 1940s, Canadian-based Eldon Boyd experimented with guaiacol and a recent synthetic modification—glycerol guaiacolate (guaifenesin)—on animals. His data showed that both drugs were effective in increasing secretions into the airways in laboratory animals, when high-enough doses were given. ==== Current uses ==== ===== Industrial ===== Wood-tar creosote is to some extent used for wood preservation, but it is generally mixed with coal-tar creosote, since the former is not as effective. Commercially available preparations of "liquid smoke", marketed to add a smoked flavour to meat and aid as a preservative, consist primarily of creosote and other constituents of smoke. Creosote is the ingredient that gives liquid smoke its function; guaicol lends to the taste and the creosote oils help act as the preservative. Creosote can be destroyed by treatment with
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{
"page_id": 69053,
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chlorine, either sodium hypochlorite, or calcium hypochlorite solutions. The phenol ring is essentially opened, and the molecule is then subject to normal digestion and normal respiration. ===== Medical ===== The guaifenesin developed by Eldon Boyd is still commonly used today as an expectorant, sold over the counter, and usually taken by mouth to assist the bringing up of phlegm from the airways in acute respiratory tract infections. Guaifenesin is a component of Mucinex, Robitussin DAC, Cheratussin DAC, Robitussin AC, Cheratussin AC, Benylin, DayQuil Mucous Control, Meltus, and Bidex 400. Seirogan is a popular Kampo medicine in Japan, used as an anti-diarrheal, and has 133 mg wood creosote from beech, pine, maple or oak wood per adult dose as its primary ingredient. Seirogan was first used as a gastrointestinal medication by the Imperial Japanese Army in Russia during the Russo-Japanese War of 1904 to 1905. Creomulsion is a cough medicine in the United States, introduced in 1925, that is still sold and contains beechwood creosote. Beechwood creosote is also found under the name kreosotum or kreosote. === Coal-tar creosote === Coal-tar creosote is greenish-brown liquid, with different degrees of darkness, viscosity, and fluorescence depending on how it is made. When freshly made, the creosote is a yellow oil with a greenish cast and highly fluorescent, and the fluorescence is increased by exposure to air and light. After settling, the oil is dark green by reflected light and dark red by transmitted light. To the naked eye, it generally appears brown. The creosote (often called "creosote oil") consists almost wholly of aromatic hydrocarbons, with some amount of bases and acids and other neutral oils. The flash point is 70–75 °C and burning point is 90–100 °C, and when burned it releases a greenish smoke. The smell largely depends on the naphtha content
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{
"page_id": 69053,
"source": null,
"title": "Creosote"
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in the creosote. If there is a high amount, it will have a naphtha-like smell, otherwise it will smell more of tar. In the process of coal-tar distillation, the distillate is collected into four fractions; the "light oil", which remains lighter than water, the "middle oil" which passes over when the light oil is removed; the "heavy oil", which sinks; and the "anthracene oil", which when cold is mostly solid and greasy, of a buttery consistence. Creosote refers to the portion of coal tar which distills as "heavy oil", typically between 230 and 270 °C, also called "dead oil"; it sinks into water but still is fairly liquid. Carbolic acid is produced in the second fraction of distillation and is often distilled into what is referred to as "carbolic oil". Commercial creosote contains substances from six groups. The two groups occur in the greatest amounts and are the products of the distillation process—the "tar acids", which distill below 205 °C and consist mainly of phenols, cresols, and xylenols, including carbolic acid—and aromatic hydrocarbons, which divide into naphthalenes, which distill approximately between 205 and 255 °C, and constituents of an anthracene nature, which distill above 255 °C. The quantity of each varies based on the quality of tar and temperatures used, but generally, the tar acids won't exceed 5%, the naphthalenes make up 15 to 50%, and the anthracenes make up 45% to 70%. The hydrocarbons are mainly aromatic; derivatives of benzene and related cyclic compounds such as naphthalene, anthracene, phenanthrene, acenaphthene, and fluorene. Creosotes from vertical-retort and low temperature tars contain, in addition, some paraffinic and olefinic hydrocarbons. The tar-acid content also depends on the source of the tar—it may be less than 3% in creosote from coke-oven tar and as high as 32% in creosote from vertical retort tar.
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"page_id": 69053,
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All of these have antiseptic properties. The tar acids are the strongest antiseptics but have the highest degree of solubility in water and are the most volatile; so, like with wood-tar creosote, phenols are not the most valued component, as by themselves they would lend to being poor preservatives. In addition, creosote contains several products naturally occurring in coal—nitrogen-containing heterocycles, such as acridines, carbazoles, and quinolines, referred to as the "tar bases" and generally make up about 3% of the creosote—sulfur-containing heterocycles, generally benzothiophenes—and oxygen-containing heterocycles, dibenzofurans. Lastly, creosote contains a small number of aromatic amines produced by the other substances during the distillation process and likely resulting from a combination of thermolysis and hydrogenation. The tar bases are often extracted by washing the creosote with aqueous mineral acid, although they're also suggested to have antiseptic ability similar to the tar acids. Commercially used creosote is often treated to extract the carbolic acid, naphthalene, or anthracene content. The carbolic acid or naphthalene is generally extracted to be used in other commercial products. In the early 20th century, American-produced creosote oils typically had low amounts of anthracene and high amounts of naphthalene, because when forcing the distillate at a temperature that produces anthracene the soft pitch will be ruined and only the hard pitch will remain; this ruined it for use in roofing purposes (which was common before widespread availability of cheap oil bitumen) and only left a product which wasn't commercially useful. ==== Historical uses ==== ===== Industrial ===== The use of coal-tar creosote on a commercial scale began in 1838, when a patent covering the use of creosote oil to treat timber was taken out by inventor John Bethell. The "Bethell process"—or as it later became known, the full-cell process—involves placing wood to be treated in a sealed chamber
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{
"page_id": 69053,
"source": null,
"title": "Creosote"
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and applying a vacuum to remove air and moisture from wood "cells". The wood is then pressure-treated to imbue it with creosote or other preservative chemicals, after which vacuum is reapplied to separate the excess treatment chemicals from the timber. Alongside the zinc chloride-based "Burnett process", use of creosoted wood prepared by the Bethell process became a principal way of preserving railway timbers (most notably railway sleepers) to increase the lifespan of the timbers, and avoiding having to regularly replace them. Besides treating wood, it was also used for lighting and fuel. In the beginning, it was only used for lighting needed in harbour and outdoor work, where the smoke that was produced from burning it was of little inconvenience. By 1879, lamps had been created that ensured a more complete combustion by using compressed air, removing the drawback of the smoke. Creosote was also processed into gas and used for lighting that way. As a fuel, it was used to power ships at sea and blast furnaces for different industrial needs, once it was discovered to be more efficient than unrefined coal or wood. It was also used industrially for the softening of hard pitch, and burned to produce lamp black. By 1890, the production of creosote in the United Kingdom totaled approximately 29,900,000 gallons per year. In 1854, Alexander McDougall and Robert Angus Smith developed and patented a product called McDougall's Powder as a sewer deodorant; it mainly consisted of carbolic acid derived from creosote. McDougall, in 1864, experimented with his solution to remove entozoa parasites from cattle pasturing on a sewage farm. This later led to widespread use of creosote as a cattle wash and sheep dip. External parasites would be killed in a creosote diluted dip, and drenching tubes would be used to administer doses to
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{
"page_id": 69053,
"source": null,
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the animals' stomachs to kill internal parasites. Creosoted wood blocks were a common road-paving material in the late 19th and early 20th centuries, but ultimately fell out of favor because they did not generally hold up well enough over time. Two later methods for creosoting wood were introduced after the turn of the century, referred to as empty-cell processes, because they involve compressing the air inside the wood so that the preservative can only coat the inner cell walls rather than saturating the interior cell voids. This is a less effective, though usually satisfactory, method of treating the wood, but is used because it requires less of the creosoting material. The first method, the "Rüping process" was patented in 1902, and the second, the "Lowry process" was patented in 1906. Later in 1906, the "Allardyce process" and "Card process" were patented to treat wood with a combination of both creosote and zinc chloride. In 1912, it was estimated that a total of 150,000,000 gallons were produced in the US per year. ===== Medical ===== Coal-tar creosote, despite its toxicity, was used as a stimulant and escharotic, as a caustic agent used to treat ulcers and malignancies, cauterize wounds, and prevent infection and decay. It was particularly used in dentistry to destroy tissues and arrest necrosis. ==== Current uses ==== ===== Industrial ===== Coal-tar creosote is the most widely used wood treatment today; both industrially, processed into wood using pressure methods such as "full-cell process" or "empty-cell process", and more commonly applied to wood through brushing. In addition to toxicity to fungi, insects, and marine borers, it serves as a natural water repellent. It is commonly used to preserve and waterproof railroad ties, pilings, telephone poles, power line poles, marine pilings, and fence posts. Although suitable for use in preserving the
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{
"page_id": 69053,
"source": null,
"title": "Creosote"
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structural timbers of buildings, it is not generally used that way because it is difficult to apply. There are also concerns about the environmental impact of the leaching of creosote into aquatic ecosystems. Due to its carcinogenic character, the European Union has regulated the quality of creosote for the EU market and requires that the sale of creosote be limited to professional users. The United States Environmental Protection Agency regulates the use of coal-tar creosote as a wood preservative under the provisions of the Federal Insecticide, Fungicide, and Rodenticide Act. Creosote is considered a restricted-use pesticide and is only available to licensed pesticide applicators. === Oil-tar creosote === Oil-tar creosote is derived from the tar that forms when using petroleum or shale oil in the manufacturing of gas. The distillation of the tar from the oil occurs at very high temperatures; around 980 °C. The tar forms at the same time as the gas, and once processed for creosotes contains a high percentage of cyclic hydrocarbons, a very low amount of tar acids and tar bases, and no true anthracenes have been identified. Historically, this has mainly been produced in the United States on the Pacific coast, where petroleum has been more abundant than coal. Limited quantities have been used industrially, either alone, mixed with coal-tar creosote, or fortified with pentachlorophenol. === Water-gas-tar creosote === Water-gas-tar creosote is also derived from petroleum oil or shale oil, but by a different process; it is distilled during the production of water gas. The tar is a by-product resulting from enrichment of water gas with gases produced by thermal decomposition of petroleum. Of the creosotes derived from oil, it is practically the only one used for wood preservation. It has the same degree of solubility as coal-tar creosote and is easy to infuse
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{
"page_id": 69053,
"source": null,
"title": "Creosote"
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into wood. Like standard oil-tar creosote, it has a low amount of tar acids and tar bases, and has less antiseptic qualities. Petri dish tests have shown that water-gas-tar creosote is one-sixth as anti-septically effective as that of coal-tar. === Lignite-tar creosote === Lignite-tar creosote is produced from lignite rather than bituminous coal, and varies considerably from coal-tar creosote. Also called "lignite oil", it has a very high content of tar acids, and has been used to increase the tar acids in normal creosote when necessary. When it has been produced, it has generally been applied in mixtures with coal-tar creosote or petroleum. Its effectiveness when used alone has not been established. In an experiment with southern yellow pine fence posts in Mississippi, straight lignite-tar creosote was giving good results after about 27 years exposure, although not as good as the standard coal-tar creosote used in the same situation. === Peat-tar creosote === There have also been attempts to distill creosote from peat-tar, although mostly unsuccessful due to the problems with winning and drying peat on an industrial scale. Peat tar by itself has in the past been used as a wood preservative. == Health effects == According to the Agency for Toxic Substances and Disease Registry (ATSDR), eating food or drinking water contaminated with high levels of coal-tar creosote may cause a burning in the mouth and throat, and stomach pains. ATSDR also states that brief direct contact with large amounts of coal-tar creosote may result in a rash or severe irritation of the skin, chemical burns of the surfaces of the eyes, convulsions and mental confusion, kidney or liver problems, unconsciousness, and even death. Longer direct skin contact with low levels of creosote mixtures or their vapours can result in increased light sensitivity, damage to the cornea, and
|
{
"page_id": 69053,
"source": null,
"title": "Creosote"
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skin damage. Longer exposure to creosote vapours can cause irritation of the respiratory tract. The International Agency for Research on Cancer (IARC) has determined that coal-tar creosote is probably carcinogenic to humans, based on adequate animal evidence and limited human evidence. The animal testing relied upon by IARC involved the continuous application of creosote to the shaved skin of rodents. After weeks of creosote application, the animals developed cancerous skin lesions and in one test, lesions of the lung. The United States Environmental Protection Agency has stated that coal-tar creosote is a probable human carcinogen based on both human and animal studies. As a result, the Federal Occupational Safety and Health Administration (OSHA) has set a permissible exposure limit of 0.2 milligrams of coal-tar creosote per cubic meter of air (0.2 mg/m3) in the workplace during an 8-hour day, and the Environmental Protection Agency (EPA) requires that spills or accidental releases into the environment of one pound (0.454 kg) or more of creosote be reported to them. There is no unique exposure pathway of children to creosote. Children exposed to creosote probably experience the same health effects seen in adults exposed to creosote. It is unknown whether children differ from adults in their susceptibility to health effects from creosote. A 2005 mortality study of creosote workers found no evidence supporting an increased risk of cancer death, as a result of exposure to creosote. Based on the findings of the largest mortality study to date of workers employed in creosote wood treating plants, there is no evidence that employment at creosote wood-treating plants or exposure to creosote-based preservatives was associated with any significant mortality increase from either site-specific cancers or non-malignant diseases. The study consisted of 2,179 employees at eleven plants in the United States where wood was treated with creosote
|
{
"page_id": 69053,
"source": null,
"title": "Creosote"
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preservatives. Some workers began work in the 1940s to 1950s. The observation period of the study covered 1979–2001. The average length of employment was 12.5 years. One third of the study subjects were employed for over 15 years. The largest health effect of creosote is deaths caused by residential chimney fires due to chimney tar (creosote) build-up. This is entirely unconnected with its industrial production or use. == Build-up in chimneys == Burning wood and fossil fuels in the absence of adequate airflow (such as in an enclosed furnace or stove), causes incomplete combustion of the oils in the wood, which are off-gassed as volatiles in the smoke. As the smoke rises through the chimney it cools, causing water, carbon, and volatiles to condense on the interior surfaces of the chimney flue. The black oily residue that builds up is referred to as creosote, which is similar in composition to the commercial products by the same name, but with a higher content of carbon black. Over the course of a season creosote deposits can become several inches thick. This creates a compounding problem, because the creosote deposits reduce the draft (airflow through the chimney) which increases the probability that the wood fire is not getting enough air for complete combustion. Since creosote is highly combustible, a thick accumulation creates a fire hazard. If a hot fire is built in the stove or fireplace, and the air control left wide open, this may allow hot oxygen into the chimney where it comes in contact with the creosote which then ignites—causing a chimney fire. Chimney fires often spread to the main building because the chimney gets so hot that it ignites any combustible material in direct contact with it, such as wood. The fire can also spread to the main building from
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{
"page_id": 69053,
"source": null,
"title": "Creosote"
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sparks emitting from the chimney and landing on combustible roof surfaces. In order to properly maintain chimneys and heaters that burn wood or carbon-based fuels, the creosote buildup must be removed. Chimney sweeps perform this service for a fee. == Release into environment == Even though creosote is pressurized into the wood, the release of the chemical – and resulting marine pollution – occurs due to many different events: During the lifetime of the marine piling, weathering occurs from tides and water flow which slowly opens the oily outer coating and exposes the smaller internal pores to more water flow. Frequent weathering occurs daily, but more severe weather, such as hurricanes, can cause damage or loosening of the wooden pilings. Many pilings are either broken into pieces from debris, or are completely washed away during these storms. When the pilings are washed away, they come to settle on the bottom of the body of water where they reside, and then they leach chemicals into the water slowly over a long period of time. This long-term secretion is not normally noticed because the piling is submerged beneath the surface, hidden from sight. The creosote is mostly insoluble in water, but the lower-molecular-weight compounds will become soluble the longer the broken wood is exposed to the water. In this case, some of the chemicals become water-soluble and further leach into the aquatic sediment while the rest of the insoluble chemicals remain together in a tar-like substance. Another source of damage comes from wood-boring fauna, such as shipworms and Limnoria. Though creosote is used as a pesticide preservative, studies have shown that Limnoria is resistant to wood preservative pesticides and can cause small holes in the wood, through which creosote can then be released. == Chemical reactions with sediment and organisms == Once
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{
"page_id": 69053,
"source": null,
"title": "Creosote"
}
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the soluble compounds from the creosote preservative leach into the water, the compounds begin reacting with the external environment or are consumed by organisms. The reactions vary depending on the concentration of each compound that is released from the creosote, but major reactions are outlined below: === Alkylation === Alkylation occurs when a molecule replaces a hydrogen atom with an alkyl group that generally comes from an organic molecule. Alkyl groups that are found naturally occurring in the environment are organometallic compounds. Organometallic compounds generally contain a methyl, ethyl, or butyl derivative which is the alkyl group that replaces the hydrogen. Other organic compounds, such as methanol, can provide alkyl groups for alkylation. Methanol is found naturally in the environment in small concentrations, and has been linked to the release from biological decomposition of waste and even a byproduct of vegetation. The following reactions are alkylations of soluble compounds found in creosote preservatives with methanol. ==== m-Cresol ==== The diagram above depicts a reaction between m-cresol and methanol where a c-alkylation product is produced. The c-alkylation reaction means that instead of replacing the hydrogen atom on the -OH group, the methyl group (from the methanol) replaces the hydrogen on a carbon in the benzene ring. The products of this c-alkylation can be in either a para- or ortho- orientation on the molecule, as seen in the diagram, and water, which is not shown. Isomers of the dimethylphenol (DMP) compound are the products of the para- and ortho-c-alkylation. Dimethylphenol (DMP) compound is listed as an aquatic hazard by characteristic, and is toxic with long lasting effects. ==== Phenol ==== This diagram shows an o-alkylation between phenol and methanol. Unlike the c-alkylation, the o-alkylation replaces the hydrogen atom on the -OH group with the methyl group (from the methanol). The product of
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{
"page_id": 69053,
"source": null,
"title": "Creosote"
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the o-alkylation is methoxybenzene, better-known as anisole, and water, which is not shown in the diagram. Anisole is listed as an acute hazard to aquatic life with long-term effects. === Bioaccumulation === Bioaccumulation is the process by which an organism takes in chemicals through ingestion, exposure, and inhalation. Bioaccumulation is broken down into bioconcentration (uptake of chemicals from the environment) and biomagnification (increasing concentration of chemicals as they move up the food chain). Certain species of aquatic organisms are affected differently from the chemicals released from creosote preservatives. One of the more studied organisms is a mollusk. Mollusks attach to the wooden, marine pilings and are in direct contact with the creosote preservatives. Many studies have been conducted using polycyclic aromatic hydrocarbons (PAH), which are low molecular hydrocarbons found in some creosote-based preservatives. In a study conducted from Pensacola, Florida, a group of native mollusks were kept in a controlled environment, and a different group of native mollusks were kept in an environment contaminated with creosote preservatives. The mollusks in the contaminated environment were shown to have a bioaccumulation of up to ten times the concentration of PAH than the control species. The intake of organisms is dependent on whether the compound is in an ionized or an un-ionized form. To determine whether the compound is ionized or un-ionized, the pH of the surrounding environment must be compared to the pKa or acidity constant of the compound. If the pH of the environment is lower than the pKa, then the compound is un-ionized which means that the compound will behave as if it is non-polar. Bioaccumulation for un-ionized compounds comes from partitioning equilibrium between the aqueous phase and the lipids in the organism. If the pH is higher than the pKa, then the compound is considered to be in the
|
{
"page_id": 69053,
"source": null,
"title": "Creosote"
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ionized form. The un-ionized form is favored because the bioaccumulation is easier for the organism to intake through partitioning equilibrium. The table below shows a list of pKas from compounds found in creosote preservatives and compares them to the average pH of seawater (reported to be 8.1). Each of the compounds in the table above is found in creosote preservatives; all are in the favored un-ionized form. In another study, various species of small fish were tested to see how the exposure time to PAH chemicals affected the fish. This study showed that an exposure time of 24–96 hours on various shrimp and fish species affected the growth, reproduction, and survival functions of the organisms for most of the compounds tested. === Biodegradation === It can be seen in some studies that biodegradation accounts for the absence of creosote preservatives on the initial surface of the sediment. In a study from Pensacola, Florida, PAHs were not detected on the surface on the aquatic sediment, but the highest concentrations were detected at a depth of 8-13 centimeters. A form an anaerobic biodegradation of m-cresol was seen in a study using sulfate-reducing and nitrate-reducing enriched environments. The reduction of m-cresol in this study was seen in under 144 hours, while additional chemical intermediates were being formed. The chemical intermediates were formed in the presence of bicarbonate. The products included 4-hydroxy-2-methylbenzoic acid and acetate compounds. Although the conditions were enriched with the reducing anaerobic compounds, sulfate and nitrate reducing bacteria are commonly found in the environment. For further information, see sulfate-reducing bacteria. The type of anaerobic bacteria ultimately determines the reduction of the creosote preservative compounds, while each individual compound may only go through reduction under certain conditions. BTEX is a mixture of benzene, toluene, ethylbenzene, and xylene, that was studied in the
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"page_id": 69053,
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presence of four different anaerobic-enriched sediments. Though the compound, BTEX, is not found in creosote preservatives, the products of creosote preservatives' oxidation-reduction reactions include some of these compounds. For oxidation-reduction reactions, see the following section. In this study, it was seen that certain compounds such as benzene were only reduced under sulfate-enriched environments, while toluene was reduced under a variety of bacteria-enriched environments, not just sulfate. The biodegradation of a creosote preservative in an anaerobic enrichment depends not only on the type of bacteria enriching the environment, but also the compound that has been released from the preservative. In aerobic environments, preservative compounds are limited in the biodegradation process by the presence of free oxygen. In an aerobic environment, free oxygen comes from oxygen saturated sediments, sources of precipitation, and plume edges. The free oxygen allows for the compounds to be oxidized and decomposed into new intermediate compounds. Studies have shown that when BTEX and PAH compounds were placed in aerobic environments, the oxidation of the ring structures caused cleavage in the aromatic ring and allowed for other functional groups to attach. When an aromatic hydrocarbon was introduced to the molecular oxygen in experimental conditions, a dihydrodiol intermediate was formed, and then oxidation occurred transforming the aromatic into a catechol compound. Catechol allows for cleavage of the aromatic ring to occur, where functional groups can then add in an ortho- or meta- position. === Oxidation-reduction === Even though many studies conduct testing under experimental or enriched conditions, oxidation-reduction reactions occur naturally and allow for chemicals to go through processes such as biodegradation, outlined above. Oxidation is defined as the loss of an electron to another species, while reduction is the gaining of an electron from another species. As compounds go through oxidation and reduction in sediments, the preservative compounds are
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"page_id": 69053,
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altered to form new chemicals, leading to decomposition. An example of the oxidation of p-cresol and phenol can be seen in the figures below: ==== p-Cresol ==== This reaction shows the oxidation of p-cresol in a sulfate-enriched environment. P-cresol was seen to be the easiest to degrade through the sulfate-enriched environment, while m-cresol and o-cresol where inhibited. In the chart above, p-cresol was oxidized under an anaerobic sulfate reducing condition and formed four different intermediates. After the formation of the intermediates, the study reported further degradation of the intermediates leading to the production of carbon dioxide and methane. The p-hydroxylbenzyl alcohol, p-hydroxylbenzaldehye, p-hyrdoxylbenzoate, and benzoate intermediates all are produced from this oxidation and released into the sediments. Similar results were also produced by different studies using other forms of oxidation such as: iron-reducing organisms, Copper/Manganese Oxide catalyst, and nitrate- reducing conditions. ==== Phenol ==== This reaction shows the oxidation of phenol by iron and peroxide. This combination of iron, which comes from iron oxide in the sediment, and the peroxide, commonly released by animals and plants into the environment, is known as the Fenton Reagent. This reagent is used to oxidize phenol groups by the use of a radical hydroxide group produced from the peroxide in the p-benzoquinone. This product of phenol's oxidation is now leached into the environment while other products include iron(II) and water. P-benzoquinone is listed as being a very toxic, acute environmental hazard. == Environmental hazards == === Sediment === In aquatic sediments, several reactions can transform the chemicals released by the creosote preservatives into more dangerous chemicals. Most creosote preservative compounds have hazards associated with them before they are transformed. Cresol (m-, p-, and o-), phenol, guaiacol, and xylenol (1,3,4- and 1,3,5-) all are acute aquatic hazards prior to going through chemical reactions with the
|
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sediments. Alkylation reactions allows for the compounds to transition into more toxic compounds with the addition of R-groups to the major compounds found in creosote preservatives. Compounds formed through alkylation include: 3,4-dimethylphenol, 2,3-dimethylphenol, and 2,5-dimethylphenol, which are all listed as acute environmental hazards. Biodegradation controls the rate at which the sediment holds the chemicals, and the number of reactions that are able to take place. The biodegradation process can take place under many different conditions, and vary depending on the compounds that are released. Oxidation-reduction reactions allow for the compounds to be broken down into new forms of more toxic molecules. Studies have shown oxidation-reduction reactions of creosote preservative compounds included compounds that are listed as environmental hazards, such as p-benzoquinone in the oxidation of phenol. Not only are the initial compounds in creosote hazardous to the environment, but the byproducts of the chemical reactions are environmental hazardous as well. === Other === From the contamination of the sediment, more of the ecosystem is affected. Organisms in the sediment are now exposed to the new chemicals. Organisms are then ingested by fish and other aquatic animals. These animals now contain concentrations of hazardous chemicals which were secreted from the creosote. Other issues with ecosystems include bioaccumulation. Bioaccumulation occurs when high levels of chemicals are passed to aquatic life near the creosote pilings. Mollusks and other smaller crustaceans are at higher risk because they are directly attached to the surface of wood pilings that are filled with creosote preservative. Studies show that mollusks in these environments take on high concentrations of chemical compounds which will then be transferred through the ecosystem's food chain. Bioaccumulation contributes to the higher concentrations of chemicals within the organisms in the aquatic ecosystems. == See also == Creolin Pentachlorophenol == Notes == == References == ==
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"page_id": 69053,
"source": null,
"title": "Creosote"
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External links ==
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{
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"source": null,
"title": "Creosote"
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A plant geneticist is a scientist involved with the study of genetics in botany. Typical work is done with genes in order to isolate and then develop certain plant traits. Once a certain trait, such as plant height, fruit sweetness, or tolerance to cold, is found, a plant geneticist works to improve breeding methods to ensure that future plant generations possess the desired traits. Plant genetics played a key role in the modern-day theories of heredity, beginning with Gregor Mendel's study of pea plants in the 19th century. The occupation has since grown to encompass advancements in biotechnology that have led to greater understanding of plant breeding and hybridization. Commercially, plant geneticists are sometimes employed to develop methods of making produce more nutritious, or altering plant pigments to make the food more enticing to consumers. == References == National Science Teachers Association: Plant Geneticist Interview Archived 2011-06-07 at the Wayback Machine USDA Agriculture Research Service
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{
"page_id": 9571778,
"source": null,
"title": "Plant geneticist"
}
|
Kai Manne Börje Siegbahn (20 April 1918 – 20 July 2007) was a Swedish physicist who shared the 1981 Nobel Prize in Physics. == Biography == Siegbahn was born in Lund, Sweden, son of Manne Siegbahn the 1924 physics Nobel Prize winner. Siegbahn earned his doctorate at the Stockholm University in 1944. He was professor at the Royal Institute of Technology 1951–1954, and then professor of experimental physics at Uppsala University 1954–1984, which was the same chair his father had held. He shared the 1981 Nobel Prize in Physics with Nicolaas Bloembergen and Arthur Schawlow. Siegbahn received half the prize "for his contribution to the development of high-resolution electron spectroscopy" while Bloembergen and Schawlow received one quarter each "for their contribution to the development of laser spectroscopy". Siegbahn referred to his technique as Electron Spectroscopy for Chemical Analysis (ESCA); it is now usually known as X-ray photoelectron spectroscopy (XPS). In 1967 he published a book, ESCA; atomic, molecular and solid state structure studied by means of electron spectroscopy. He was a member of several academies and societies, including the Royal Swedish Academy of Sciences, and was president of the International Union of Pure and Applied Physics from 1981 to 1984. Siegbahn married Anna Brita Rhedin in 1944. The couple had three sons (two physicists and a biochemist). Siegbahn died on 20 July 2007 at the age of 89. At the time of his death he was still active as a scientist at the Ångström Laboratory at Uppsala University. == Awards == As well as a share of the 1981 Nobel Prize in Physics, Siegbahn won the following awards: 1945 Lindblom Prize 1955, 1977 Björkén Prize 1962 Celsius Medal 1971 Sixten Heyman Award, University of Gothenburg 1973 Harrison Howe Award, Rochester 1975 Maurice F. Hasler Award, Cleveland 1976 Charles Frederick Chandler
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{
"page_id": 396741,
"source": null,
"title": "Kai Siegbahn"
}
|
Medal, Columbia University, New York 1977 Torbern Bergman Medal 1982 Pittsburgh Award of Spectroscopy == References == == External links == Media related to Kai Siegbahn at Wikimedia Commons Kai Siegbahn on Nobelprize.org
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{
"page_id": 396741,
"source": null,
"title": "Kai Siegbahn"
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|
The Emerson effect is the increase in the rate of photosynthesis after chloroplasts are exposed to light of wavelength less than 680 nm (deep red spectrum) and more than 680 nm (far red spectrum). When simultaneously exposed to light of both wavelengths, the rate of photosynthesis is higher than the sum of the red light and far red light photosynthesis rates. The effect was early evidence that two photosystems, processing different wavelengths, cooperate in photosynthesis. == History == Robert Emerson described the eponymous effect in 1957. In his paper he observed that: When plants are exposed to light having wavelength greater than 680 nm, then only one photosystem is activated; i.e. PS700 resulting in formation of ATP only. When plants are exposed to light having wavelength less than 680 nm, the rate of photosynthesis was very low. On giving both shorter and higher wavelengths of light, the efficiency of the process increased, because both photosystems were working together at the same time, resulting in higher yield. == Description == When Emerson exposed green plants to differing wavelengths of light, he noticed that at wavelengths of greater than 680 nm the efficiency of photosynthesis decreased abruptly despite the fact that this is a region of the spectrum where chlorophyll still absorbs light (chlorophyll is the green pigment in plants - it absorbs mainly the red and blue wavelengths from light). When the plants were exposed to short-wavelength light, (less than 660 nm), the efficiency also decreased. Emerson then exposed the plants to both short and long wavelengths at the same time, causing the efficiency to increase greatly. He concluded that there must be two different photosystems involved in photosynthesis, one driven by short-wavelength light and one driven by long-wavelength (PS1 and PS2). They work together to enhance efficiency and convert the
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{
"page_id": 24251847,
"source": null,
"title": "Emerson effect"
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|
light energy to forms that can be absorbed by the plant. The light excites the chlorophyll molecules at the reaction centre and causes an increase in energy. As the molecule becomes less excited, its energy is transported through a chain of electron carriers to the next photosystem which does much the same thing and produces energy-carrying organic molecules. == References == == External links == Emerson Effect at Botany Dictionary everything2.com Emersion Effect in details at Plantphysiol.org
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{
"page_id": 24251847,
"source": null,
"title": "Emerson effect"
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|
Phosphate solubilizing bacteria (PSB) are beneficial bacteria capable of solubilizing inorganic phosphorus from insoluble compounds. P-solubilization ability of rhizosphere microorganisms is considered to be one of the most important traits associated with plant phosphate nutrition. It is generally accepted that the mechanism of mineral phosphate solubilization by PSB strains is associated with the release of low molecular weight organic acids, through which their hydroxyl and carboxyl groups chelate the cations [an ion that have positive charge on it.] bound to phosphate, thereby converting it into soluble forms. PSB have been introduced to the Agricultural community as phosphate Biofertilizer. Phosphorus (P) is one of the major essential macronutrients for plants and is applied to soil in the form of phosphate fertilizers. However, a large portion of soluble inorganic phosphate which is applied to the soil as chemical fertilizer is immobilized rapidly and becomes unavailable to plants. Currently, the main purpose in managing soil phosphorus is to optimize crop production and minimize P loss from soils. PSB have attracted the attention of agriculturists as soil inoculums to improve the plant growth and yield. When PSB is used with rock phosphate, it can save about 50% of the crop requirement of phosphatic fertilizer. The use of PSB as inoculants increases P uptake by plants. Simple inoculation of seeds with PSB gives crop yield responses equivalent to 30 kg P2O5 /ha or 50 percent of the need for phosphatic fertilizers. Alternatively, PSB can be applied through fertigation or in hydroponic operations. Many different strains of these bacteria have been identified as PSB, including Pantoea agglomerans (P5), Microbacterium laevaniformans (P7) and Pseudomonas putida (P13) strains are highly efficient insoluble phosphate solubilizers. Recently, researchers at Colorado State University demonstrated that a consortium of four bacteria, synergistically solubilize phosphorus at a much faster rate than any single
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{
"page_id": 27200967,
"source": null,
"title": "Phosphate solubilizing bacteria"
}
|
strain alone. Mahamuni and Patil (2012) isolated four strains of phosphate solubilizing bacteria from sugarcane (VIMP01 and VIMP02) and sugar beet rhizosphere (VIMP03 and VIMP 04). Isolates were strains of Burkholderia named as VIMP01, VIMP02, VIMP03 and VIMP04. VIMP (Vasantdada Sugar Institute Isolate by Mahamuni and Patil) cultures were identified as Burkholderia cenocepacia strain VIMP01 (JQ867371), Burkholderia gladioli strain VIMP02 (JQ811557), Burkholderia gladioli strain VIMP03 (JQ867372) and Burkholderia species strain VIMP04 (JQ867373). Additionally, phosphate (P) compounds are capable of immobilizing heavy metals, especially Pb, in contaminated environments through phosphate-heavy metal precipitation. However, most P compounds are not readily soluble in soils so it is not readily used for metal immobilization. Phosphate solubilizing bacteria (PSB) have the potential to enhance phosphate-induced immobilization of metals to remediate contaminated soil. However, there is a limit on the amount of phosphate which can be added to the environment due to the issue of eutrophication. Phosphate is often adsorbed onto the surface of different type of minerals, for example iron containing minerals. Recent data suggest that bacteria growing under phosphorus starvation release iron-chelating molecules. Considering the geochemical interaction between these two elements, the authors suggest that some bacteria can dissolve iron-containing minerals in order to access the adsorbed phosphate. == References == Mahamuni, S. V. and Patil, A.S. (2012). Microbial Consortium Treatment to Distillery Spent Wash and Press Mud Cake through Pit and Windrow System of Composting. Journal of Chemical, Biological and Physical Sciences. 2(2):847-855.
|
{
"page_id": 27200967,
"source": null,
"title": "Phosphate solubilizing bacteria"
}
|
The molecular formula C27H24F3NO (molar mass: 435.49 g/mol) may refer to: JWH-363 JWH-372 JWH-348
|
{
"page_id": 77401547,
"source": null,
"title": "C27H24F3NO"
}
|
This is a list of types of inflammation in the body when organised by location. == Nervous system == === CNS === Encephalitis/Cerebritis Myelitis Meningitis Cerebellitis Ventriculitis === PNS === Neuritis === Eye === Dacryoadenitis Dacryocystitis Conjunctivitis Scleritis Episcleritis Uveitis Blepharitis Keratitis Retinitis/Chorioretinitis === Ear === Otitis Labyrinthitis Otitis media Otitis Externa == Cardiovascular system == Carditis Endocarditis Myocarditis Pericarditis Vasculitis Arteritis Phlebitis Capillaritis Aortitis == Respiratory system == Sinusitis Rhinitis Pharyngitis Epiglottitis Laryngitis Tracheitis Bronchitis Bronchiolitis Pneumonitis Pneumonia Pleurisy == Digestive system == Stomatitis Cheilitis Glossitis Tonsillitis Sialadenitis Parotitis Gingivitis Pulpitis Pericoronitis Gnathitis Oesophagitis Gastritis Gastroenteritis Enteritis Duodenitis Jejunitis Ileitis Colitis Pancolitis Appendicitis Cryptitis Proctitis Diverticulitis Hepatitis Viral hepatitis Alcoholic hepatitis Autoimmune hepatitis Cholecystitis Cholangitis Pancreatitis Peritonitis Mediastinitis == Integumentary system == Dermatitis Cellulitis Erysipelas Mastitis Onychia Folliculitis Omphalitis == Musculoskeletal system == Arthritis Sacroilitis Myositis Osteitis/Osteomyelitis Spondylitis Chondritis Synovitis Tendinitis Tenosynovitis Bursitis Perichondritis Fasciitis Enthesitis Discitis Dactylitis == Urinary system == Nephritis Pyelonephritis Interstitial Nephritis Glomerulonephritis Ureteritis Cystitis Urethritis == Reproductive system == === Female === Oophoritis Salpingitis Metritis Endometritis Myometritis Parametritis Cervicitis Vaginitis Vulvitis Bartholinitis Skenitis Placentitis Villitis Intervillitis Funisitis Chorioamnionitis === Male === Orchitis Epididymitis Vasitis/Deferentitis Prostatitis Vesiculitis Cowperitis Balanitis Posthitis == Endocrine system == Insulitis Hypophysitis Thyroiditis Parathyroiditis Adrenalitis Steatitis == Lymphatic/immune system == Lymphangitis Lymphadenitis Splenitis Thymitis == References ==
|
{
"page_id": 61803980,
"source": null,
"title": "List of types of inflammation by location"
}
|
Riboflavin:NAD(P)+ oxidoreductase may refer to: Riboflavin reductase (NAD(P)H), an enzyme FMN reductase, an enzyme
|
{
"page_id": 38276558,
"source": null,
"title": "Riboflavin:NAD(P)+ oxidoreductase"
}
|
Genome in a Bottle is a consortium hosted by NIST and dedicated to characterization of benchmark human genomes. The NCBI is serving as the repository for the detailed information on samples, genotypes, raw sequencing reads and mapped reads, via a dedicated FTP site. == References ==
|
{
"page_id": 68292047,
"source": null,
"title": "Genome in a Bottle"
}
|
Roman Smoluchowski (born 31 August 1910 in Zakopane; died 12 January 1996 in Austin, Texas) was a notable physicist who worked in Poland, and after World War II settled in Institute for Advanced Study in Princeton, New Jersey. He was the son of the statistical physics pioneer Marian Smoluchowski. In 1974, Roman Smoluchowski was awarded a Guggenheim Fellowship. In 1984, the minor planet 4530 Smoluchowski was named after him. == Education and Career == Smoluchowski had a distinguished career in industrial and academic research in physics and astrophysics. He graduated from the University of Warsaw with a Master's degree in 1933, and from the University of Groningen in 1935. He spent a post-doctoral year at the Institute for Advanced Study in Princeton. Then he returned to Poland to head the Department of Physics and Metals at the University of Warsaw. Once he escaped the horrors of war and returned to the USA, he became a research physicist at the General Electric Research Laboratory in Schenectady, New York. He worked on intelligence matters there, and among the pieces of information to which he was given access was a list of Polish citizens scheduled for capture and execution by the Germans. One of the names on the list was his own. In 1946, Roman became an associate professor of metallurgy at the Carnegie Institute of Technology, and then professor of physics in 1950. In the 1950's he also began an association with the solid-state physics group at the Brookhaven National Laboratory. He was a Fulbright Fellow at the Sorbonne in 1956. In 1960, he worked at Princeton University as a professor and as the first director of the interdisciplinary program in solid state and materials science in the Department of Mechanical Engineering. In 1978 Roman retired from Princeton and became a professor
|
{
"page_id": 59641300,
"source": null,
"title": "Roman Smoluchowski"
}
|
at the University of Texas in Austin in both departments of astronomy and physics. == Escape from War == Roman escaped to Sweden from Poland in 1939, when Warsaw was caught between the Russian and German fronts. From Sweden he went to Norway, where he caught a freighter headed for the US only days before Germany invaded Norway. == Awards and Honors == -Brazil Acad Scis -Fellow AAAS -Finnish Acad Scis -1984: Planet 4530 Smoluchowski named after him -1976: Jurzykowski Award -1974: Guggenheim Fellowship --1956: Fulbright Fellowship -1938: U of Liège Lect Medal == References == == External links == === Archival links === American Physical Society Division of Solid State Physics records of Roman Smoluchowski, 1943-1947, Niels Bohr Library & Archives
|
{
"page_id": 59641300,
"source": null,
"title": "Roman Smoluchowski"
}
|
Directed differentiation is a bioengineering methodology at the interface of stem cell biology, developmental biology and tissue engineering. It is essentially harnessing the potential of stem cells by constraining their differentiation in vitro toward a specific cell type or tissue of interest. Stem cells are by definition pluripotent, able to differentiate into several cell types such as neurons, cardiomyocytes, hepatocytes, etc. Efficient directed differentiation requires a detailed understanding of the lineage and cell fate decision, often provided by developmental biology. == Conceptual frame == During differentiation, pluripotent cells make a number of developmental decisions to generate first the three germ layers (ectoderm, mesoderm and endoderm) of the embryo and intermediate progenitors, followed by subsequent decisions or check points, giving rise to all the body's mature tissues. The differentiation process can be modeled as sequence of binary decisions based on probabilistic or stochastic models. Developmental biology and embryology provides the basic knowledge of the cell types' differentiation through mutation analysis, lineage tracing, embryo micro-manipulation and gene expression studies. Cell differentiation and tissue organogenesis involve a limited set of developmental signaling pathways. It is thus possible to direct cell fate by controlling cell decisions through extracellular signaling, mimicking developmental signals. == Source material == Directed differentiation is primarily applied to pluripotent stem cells (PSCs) of mammalian origin, in particular mouse and human cells for biomedical research applications. Since the discovery of embryonic stem (ES) cells (1981) and induced pluripotent stem (iPS) cells (2006), source material is potentially unlimited. Historically, embryonic carcinoma (EC) cells have also been used. Fibroblasts or other differentiated cell types have been used for direct reprogramming strategies. == Methods == Cell differentiation involves a transition from a proliferative mode toward differentiation mode. Directed differentiation consists in mimicking developmental (embryo's development) decisions in vitro using the stem cells as source
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{
"page_id": 44305878,
"source": null,
"title": "Directed differentiation"
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material. For this purpose, pluripotent stem cells (PSCs) are cultured in controlled conditions involving specific substrate or extracellular matrices promoting cell adhesion and differentiation, and define culture media compositions. A limited number of signaling factors such as growth factors or small molecules, controlling cell differentiation, is applied sequentially or in a combinatorial manner, at varying dosage and exposure time. Proper differentiation of the cell type of interest is verified by analyzing cell type specific markers, gene expression profile, and functional assays. === Early methods === co-culture with stromal cells or feeder cells, and on specific culture substrates: support cells and matrices provide developmental-like environmental signals. 3D cell aggregate formation, termed embryoid bodies (EBs): the aggregate aim at mimicking early embryonic development and instructing the cell differentiation. culture in presence of fetal bovine serum, removal of pluripotency factors. === Current methodologies === ==== Directed differentiation ==== This method consists in exposing the cells to specific signaling pathways modulators and manipulating cell culture conditions (environmental or exogenous) to mimick the natural sequence of developmental decisions to produce a given cell type/tissue. A drawback of this approach is the necessity to have a good understanding of how the cell type of interest is formed. ==== Direct reprogramming ==== This method, also known as transdifferentiation or direct conversion, consists in overexpressing one or several factors, usually transcription factors, introduced in the cells. The starting material can be either pluripotent stem cells (PSCs), or either differentiated cell type such as fibroblasts. The principle was first demonstrated in 1987 with the myogenic factors MyoD. A drawback of this approach is the introduction of foreign nucleic acid in the cells and the forced expression of transcription factors which effects are not fully understood. ==== Lineage/cell type-specific selection ==== This methods consists in selecting the cell type of
|
{
"page_id": 44305878,
"source": null,
"title": "Directed differentiation"
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interest, usually with antibiotic resistance. For this purpose, the source material cells are modified to contain antibiotic resistance cassette under a target cell type specific promoter. Only cells committed to the lineage of interest is surviving the selection. == Applications == Directed differentiation provides a potentially unlimited and manipulable source of cell and tissues. Some applications are impaired by the immature phenotype of the pluripotent stem cells (PSCs)-derived cell type, which limits the physiological and functional studies possible. Several application domains emerged: === Model system for basic science === For basic science, notably developmental biology and cell biology, PSC-derived cells allow to study at the molecular and cellular levels fundamental questions in vitro, that would have been otherwise extremely difficult or impossible to study for technical and ethical reasons in vivo such as embryonic development of human. In particular, differentiating cells are amenable for quantitative and qualitative studies. More complex processes can also be studied in vitro and formation of organoids, including cerebroids, optic cup and kidney have been described. === Drug discovery and toxicology === Cell types differentiated from pluripotent stem cells (PSCs) are being evaluated as preclinical in vitro models of Human diseases. Human cell types in a dish provide an alternative to traditional preclinical assays using animal, human immortalized cells or primary cultures from biopsies, which have their limitations. Clinically relevant cell types i.e. cell type affected in diseases are a major focus of research, this includes hepatocytes, Langerhans islet beta-cells, cardiomyocytes and neurons. Drug screen are performed on miniaturized cell culture in multiwell-plates or on a chip. === Disease modeling === PSCs-derived cells from patients are used in vitro to recreate specific pathologies. The specific cell type affected in the pathology is at the base of the model. For example, motoneurons are used to study spinal
|
{
"page_id": 44305878,
"source": null,
"title": "Directed differentiation"
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muscular atrophy (SMA) and cardiomyocytes are used to study arrhythmia. This can allow for a better understanding of the pathogenesis and the development of new treatments through drug discovery. Immature PSC-derived cell types can be matured in vitro by various strategies, such as in vitro ageing, to model age-related disease in vitro. Major diseases being modelized with PSCs-derived cells are amyotrophic lateral sclerosis (ALS), Alzheimer's (AD), Parkinson's (PD), fragile X syndrome (FXS), Huntington disease (HD), Down syndrome, Spinal muscular atrophy (SMA), muscular dystrophies, cystic fibrosis, Long QT syndrome, and Type I diabetes. === Regenerative medicine === The potentially unlimited source of cell and tissues may have direct application for tissue engineering, cell replacement and transplantation following acute injuries and reconstructive surgery. These applications are limited to the cell types that can be differentiated efficiently and safely from human PSCs with the proper organogenesis. Decellularized organs are also being used as tissue scaffold for organogenesis. Source material can be normal healthy cells from another donor (heterologous transplantation) or genetically corrected from the same patient (autologous). Concerns on patient safety have been raised due to the possibility of contaminating undifferentiated cells. The first clinical trial using hESC-derived cells was in 2011. The first clinical trial using hiPSC-derived cells started in 2014 in Japan. == See also == Dedifferentiation Pluripotency == References ==
|
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"page_id": 44305878,
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Symmetry aspects of M. C. Escher's periodic drawings is a book by crystallographer Caroline H. MacGillavry published for the International Union of Crystallography (IUCr) by Oosthoek in 1965. The book analyzes the symmetry of M. C. Escher's colored periodic drawings using the international crystallographic notation. In 1959, MacGillavry met Escher. His work, the regular tiling of the plane, showed obvious links with the symmetry principles of crystallography. After seeking approval from the organisers (Joseph and Gabrielle Donnay), MacGillavry asked Escher to exhibit his lithographic works at the IUCr Congress in Cambridge, U.K. in 1960. The exhibition was a success, and as a consequence the IUCr commissioned MacGillavry to write the book under its auspices. == Structure and topics == The book has three chapters. In the first chapter, entitled Patterns with Classical Symmetry, the author introduces the concepts of motif, symmetry operations, lattice and unit cell, and uses these to analyze the symmetry of 13 of Escher's tiling designs. In the second chapter, Patterns with Black-white Symmetry, the antisymmetry operation (indicated by a prime ') is introduced. The chapter analyzes 22 of Escher's design in terms of black-white symmetry and assigns each a symbol in the international notation describing its symmetries. In the third chapter, Patterns with Polychromatic Symmetry, the analysis is extended to 7 of Escher's design possessing three or more colors. The book is printed in full color to facilitate the recognition of color symmetries in the images. == Audience == The publication of the book was sponsored by the IUCr and the original target audience was crystallography students learning the principles of symmetry, particularly color symmetry. In the introduction to the book the author states "Although the book is meant primarily for undergraduate students, I hope that many people who are simply amused and intrigued by Escher's
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designs will be interested to see how they illustrate the laws of symmetry". == Reception and influence == The reception of the book was positive. Robert M. Mengel in Scientific American wrote "[the author] has organized this unique and beautiful book from the corpus of marvelous spacefilling periodic drawings made over two decades by the artist Maurits C. Escher. Adding a few specially drawn for this work, Escher has here given us the classical crystal groups in the plane, and a good many more that exploit the latest extensions to color symmetry, foreseen by the artist before mathematicians had officially recognized and classified them." F. I. G. Rawlins in Acta Crystallographica wrote "Under [the author's] sure guidance the reader is skilfully conducted through such regions of the theory of symmetry as are necessary for a tolerable grasp of the full significance of these patterns, several of them produced in full colour." J. Bohm reviewed the book in Kristall Und Technik. Bohm acknowledged the special value of Escher's art as crystallographic teaching material. He praised the author for preparing the material in a detailed, crystallographically valid and didactically appealing way. Overall he stated that the book was a successful collaboration between the artist, author, publisher and the IUCr. In 1976 an announcement in the IUCr's journals stated that the book was "extremely popular" and this had a necessitated a reprint in both the Netherlands and the U.S.A. In an obituary of the author it is stated that the publication of the book helped to popularise M. C. Escher's work in the U.S.A. MacGillavry's book inspired further work on the symmetry analysis of M. C. Escher's work, particularly by Doris Schattschneider in M. C. Escher: Visions of Symmetry. == Editions == First edition published for International Union of Crystallography by Oosthoek in
|
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"page_id": 76352984,
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"title": "Symmetry aspects of M. C. Escher's periodic drawings"
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1965 Second edition published for International Union of Crystallography by Bohn, Scheltema & Holkema in 1976 Reprint edition with the title Fantasy & symmetry: the periodic drawings of M. C. Escher published by Harry N. Abrams in 1976 Third edition published by International Union of Crystallography in 2017 == References == == External links == MacGillavry, Caroline H. (1976). Fantasy & symmetry: the periodic drawings of M. C. Escher. H. N. Abrams. ISBN 978-0-8109-0850-5. at the Internet Archive
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"title": "Symmetry aspects of M. C. Escher's periodic drawings"
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Ibn Sahl (full name: Abū Saʿd al-ʿAlāʾ ibn Sahl Persian: ابوسعدالعلاءِبن سعل (ابن سهل); c. 940–1000) was a Persian mathematician and physicist of the Islamic Golden Age, associated with the Buyid court of Baghdad. Nothing in his name allows us to glimpse his country of origin. He is known to have written an optical treatise around 984. The text of this treatise was reconstructed by Roshdi Rashed from two manuscripts (edited 1993).: Damascus, al-Ẓāhirīya MS 4871, 3 fols., and Tehran, Millī MS 867, 51 fols. The Tehran manuscript is much longer, but it is badly damaged, and the Damascus manuscript contains a section missing entirely from the Tehran manuscript. The Damascus manuscript has the title Fī al-'āla al-muḥriqa "On the burning instruments", the Tehran manuscript has a title added in a later hand Kitāb al-harrāqāt "The book of burners". Ibn Sahl is the first Muslim scholar known to have studied Ptolemy's Optics, and as such an important precursor to the Book of Optics by Ibn Al-Haytham (Alhazen), written some thirty years later. Ibn Sahl dealt with the optical properties of curved mirrors and lenses and has been described as the discoverer of the law of refraction (Snell's law). Ibn Sahl uses this law to derive lens shapes that focus light with no geometric aberrations, known as anaclastic lenses. In the remaining parts of the treatise, Ibn Sahl dealt with parabolic mirrors, ellipsoidal mirrors, biconvex lenses, and techniques for drawing hyperbolic arcs. Ibn Sahl designed convex lenses that focus light rays that are parallel, which can cause an object to burn at a specific distance. == See also == History of optics Abū Sahl al-Qūhī List of Persian scientists and scholars Snell's law == References == == Sources == Rashed, R. "A pioneer in anaclastics: Ibn Sahl on burning mirrors and
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lenses", Isis 81, pp. 464–491, 1990. Rashed, R., Géométrie et dioptrique au Xe siècle: Ibn Sahl, al-Quhi et Ibn al-Haytham. Paris: Les Belles Lettres, 1993 Zghal, Mourad; et al. (2007). Nantel, Marc (ed.). "The first steps for learning optics: Ibn Sahl's, Al- Haytham's and Young's works on refraction as typical examples" (PDF). The Education and Training in Optics and Photonics Conference. Tenth International Topical Meeting on Education and Training in Optics and Photonics. 9665. International Commission for Optics: 3. Bibcode:2007SPIE.9665E..09Z. doi:10.1117/12.2207465. S2CID 13875045. Retrieved 20 June 2011. Berggren, Len (2007). "Ibn Sahl: Abū Saʿd al-ʿAlāʾ ibn Sahl". In Thomas Hockey; et al. (eds.). The Biographical Encyclopedia of Astronomers. New York: Springer. p. 567. ISBN 978-0-387-31022-0. (PDF version) Selin, Helaine (1997). Encyclopaedia of the History of Science, Technology, and Medicine in Non-Western Cultures. Springer Science & Business Media. pp. 432–433. ISBN 978-07-92-34066-9. Sarmiş, İbrahım (1999). İBN SEHL - An article published in Turkish Encyclopedia of Islam. Vol. 20. Istanbul: TDV İslâm Ansiklopedisi. p. 312. ISBN 978-97-53-89447-0.
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"page_id": 2231772,
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"title": "Ibn Sahl (mathematician)"
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Professor Lisa O. Roberts is vice chancellor and President of the University of Exeter. She took over from professor Steve Smith on his retirement on 1 September 2020. == Early life == In 1990, Roberts graduated with a Bachelor of Science in medical microbiology and general microbiology from the University of Birmingham. == Career == After graduation, Roberts joined Procter and Gamble as a product development manager in the UK and Belgium. In 1995, she moved to the BBSRC Institute for Animal Health (now the Pirbright Institute) and the University of Kent, where she studied for a PhD in molecular virology. In 1998, she joined the University of Surrey academic staff, where she became lecturer, senior lecturer, and professor of virology. By 2012, she was executive dean of the Faculty of Health and Medical Sciences at the University of Surrey, where she launched a new school of veterinary medicine In 2016, she moved to the University of Leeds. In 2019, it was announced that she would succeed Sir Steve Smith on his retirement as vice-chancellor and chief executive at the University of Exeter as of 1 September 2020. In 2022, Professor Roberts was made Chair of the Department for Education Spiking Working Group to lead a group of academics, practitioners and student victims to improve the prevention of and responses to spiking. == Publications == == References ==
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Hazard analysis and risk-based preventive controls or HARPC is a successor to the Hazard analysis and critical control points (HACCP) food safety system, mandated in the United States by the FDA Food Safety Modernization Act (FSMA) of 2010. Preventive control systems emphasize prevention of risks before they occur rather than their detection after they occur. The FDA released the rules in the Federal Register from September 2015 onwards. The first release of rules addressed Preventive Controls for Human Food and Preventive Controls for Foods for Animals. The Produce Safety Final Rule, the Foreign Supplier Verification Programs (FSVP) Final Rule and the Accredited Third-Party Certification Final Rule were issued on November 13, 2015. The Sanitary Transportation of Human and Animal Food final rule was issued on April 6, 2016, and the Mitigation Strategies To Protect Food Against Intentional Adulteration (Food Defense) final rule was issued on May 27, 2016. == Scope == All food companies in the United States that are required to register with the FDA under the Public Health Security and Bioterrorism Preparedness and Response Act of 2002, as well as firms outside the US that export food to the US, must have a written FSMA-compliant Food Safety Plan in place by the deadlines listed below: Very small businesses of less than $1 million in sales per year are exempt, but must provide proof to the FDA of their very small status by January 1, 2016. Businesses subject to Juice HACCP (21 CFR 120) and Seafood HACCP (21 CFR 123) are exempt. Businesses subject to the Pasteurized Milk Ordinance; Sept 17, 2018. Small businesses, defined as having fewer than 500 full-time equivalent employees; Sept 17, 2017. All other businesses; Sept 17, 2016. Additionally, for the first time food safety is being extended to pet food and animal feed, with
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firms being given an extra year to implement Current Good Manufacturing Practices before a Preventive Controls system the following year: Primary Production Farms, defined as "an operation under one management in one general, but not necessarily contiguous, location devoted to the growing of crops, the harvesting of crops, the raising of animals (including seafood), or any combination of these activities" are exempt. Very small businesses of less than $2,500,000 in sales per year; Sept 17, 2018 for cGMP, Sept 17, 2019 for Preventive Controls, but must provide proof of very small business status by January 1, 2017. Small businesses, having fewer than 500 full-time equivalent employees; Sept 17, 2017 for cGMP, Sept 17, 2018 for Preventive Controls. All other businesses; Sept 17, 2016 for cGMP, Sept 17, 2017 for Preventive Controls. The FDA estimates that 73,000 businesses currently fall under these definitions. == Differences between FSMA Preventive Controls and HACCP == FSMA places a much stronger emphasis on science, research and prior experience with outbreaks than HACCP. For example, the FDA now uses whole genome sequencing to match the exact strain of pathogen isolated from hospital patients to DNA recovered from food manufacturing facilities. FSMA requires that a "Preventive Controls Qualified Individual" (PCQI) with training and experience oversee the plan. HACCP assigned responsibilities to a team drawn from management. FSMA requires that firms vet ("Verify") all their suppliers for the effectiveness of their food safety programs. This has the effect of drafting companies into the FSMA enforcement effort, since the Supplier Verification and Foreign Supplier Verification programs require that the suppliers provide written proof that they have Prerequisite Programs, and Preventive Controls systems which include their own supplier vetting program. FSMA-compliant Food Safety Plans rely on Prerequisite Programs such as GMPs, allergen controls, Integrated Pest Management and vetting suppliers far
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more than HACCP plans, since these programs tend to be preventive. FSMA-compliant Hazard Analyses address radiological hazards in addition to the chemical, biological and physical hazards covered by HACCP systems. FSMA explicitly requires a Food Defense component, with both terrorism and Economically Motivated Adulteration addressed. Businesses with less than $10,000,000 a year in sales are exempt. FSMA-compliant Food Safety Plans de-emphasize Critical Control Points in favor of Preventive Controls. Preventive Controls do not require specific Critical Limits. FSMA-compliant Food Safety Plans allow Corrections in place of Corrective Actions when the public health is not threatened. Corrections are not as strict regarding paperwork as Corrective Actions. The FDA believes that companies might have been avoiding making minor improvements because they felt that the paper trail of a Corrective Action would open them to legal risk due to discovery during investigations or lawsuits. FSMA-compliant Food Safety Plans are to be reviewed once every three years, as opposed to yearly with HACCP. == See also == == References == == External links == Food Safety Preventive Controls Alliance's Preventive Controls for Human Food
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{
"page_id": 47779300,
"source": null,
"title": "Hazard analysis and risk-based preventive controls"
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Stem Cell Reports is a monthly peer-reviewed open access journal covering research into stem cells. It was established in 2013 and is published exclusively online by Cell Press. It is the official journal of the International Society for Stem Cell Research. The editor-in-chief is Martin Pera (Jackson Laboratory). According to the Journal Citation Reports, the journal has a 2020 impact factor of 7.765. == References == == External links == Official website
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"source": null,
"title": "Stem Cell Reports"
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The molecular formula C33H38N4O6 (molar mass: 586.67 g/mol) may refer to: Irinotecan, a drug used for the treatment of cancer Phycocyanobilin, a blue phycobilin Phycoerythrobilin, a red phycobilin
|
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"page_id": 24120806,
"source": null,
"title": "C33H38N4O6"
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Stem cell tourism, a form of medical tourism, is the internet based-industry in which stem cell procedures are advertised to the public as a proven cure. In the majority of cases, it leads to patients and families traveling abroad to obtain procedures that are not proven, nor part of a clinical trial approved by an authority like the Food and Drug Administration in the United States. These procedures have not gone through the vetting process of clinical research and they lack rigorous scientific support. Although for the general public, this advertising in glossy websites, may sound authoritative, for translational doctors and scientists this leads to the exploitation of vulnerable patients. These procedures lack the reproducibility, the rigor that is required for successful development of new effective medications. Although the term may imply traveling overseas, in recent years, there has been an explosion of "stem cell clinics' in the US which has been well documented. These activities are highly profitable for the clinic but no benefit for the patients, sometimes experiencing complications like spinal tumors, death, or financial ruin, all of which are documented in the scientific literature. There is a great deal of interest in educating the public and patients, families and doctors who deal with patients requesting stem cells clinics. In recent years, the FDA has become more active in overseeing stem cell clinics, taking a number of concrete steps including sending warning letters, putting out advisories, and in two cases filing suit in federal court to impose permanent injunctions on specific clinic firms. Despite the great interest generated in the public for the use of stem cells, among all stem cell scientists, including the International Society for Stem Cell Research, the largest academic organization of scientist and advocates for stem cell research in the world. Stem cell "therapy"
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is an aspirational goal, is still under development and although there is a great deal of research around the world. Rigorous stem cell trials are still ongoing and patients should be educated to be aware of the unethical clinics in the US or abroad, that offer stem cells procedures as a cure when it is still under investigation. Furthermore, there is confusion in the general public between the concept of the "right to try" (RTT) legislation to the right to pursue any"stem cell preparations'. These are different concepts. RTT is usually approved for promising pharmacological compounds that have earned a sound scientific or pre-clinical support. In contrast to stem cell tourism infusions that do not. One of the key elements in the RTT is the concept of promising, that is not just a theoretical possibility but a demonstrable and reproducible evidence obtained by scientific experimentation. The right to try legislation seek opportunities for incurables and often terminal patients to receive the compassionate use of experimental therapies that have passed phase I clinical trials that have not gone through all the checks and balances needed for approval. In contrast to the stem cell tourism, these trials have oversight by the FDA and there is no direct financial exploitation for the patient and families. == References ==
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{
"page_id": 64228839,
"source": null,
"title": "Stem cell tourism"
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Given a topological space M, a topological group G and a principal G-bundle over M, a global section of that principal bundle is a gauge fixing and the process of replacing one section by another is a gauge transformation. If a gauge transformation isn't homotopic to the identity, it is called a large gauge transformation. In theoretical physics, M often is a manifold and G is a Lie group. == See also == Large diffeomorphism Global anomaly == References ==
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{
"page_id": 2690531,
"source": null,
"title": "Large gauge transformation"
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Aare Laht (born 6 June 1948) is an Estonian chemist. He has worked at National Institute of Chemical Physics and Biophysics In 1980, he was among the signatories of the Letter of 40 intellectuals. In 2006, he was awarded with Order of the National Coat of Arms, IV class. == References ==
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The molecular formula C33H42N4O6 (molar mass: 590.71 g/mol, exact mass: 590.310435 u) may refer to: Phycourobilin, a tetrapyrrole Urobilin, a tetrapyrrole
|
{
"page_id": 24120812,
"source": null,
"title": "C33H42N4O6"
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An electrochemical gradient is a gradient of electrochemical potential, usually for an ion that can move across a membrane. The gradient consists of two parts: The chemical gradient, or difference in solute concentration across a membrane. The electrical gradient, or difference in charge across a membrane. If there are unequal concentrations of an ion across a permeable membrane, the ion will move across the membrane from the area of higher concentration to the area of lower concentration through simple diffusion. Ions also carry an electric charge that forms an electric potential across a membrane. If there is an unequal distribution of charges across the membrane, then the difference in electric potential generates a force that drives ion diffusion until the charges are balanced on both sides of the membrane. Electrochemical gradients are essential to the operation of batteries and other electrochemical cells, photosynthesis and cellular respiration, and certain other biological processes. == Overview == Electrochemical energy is one of the many interchangeable forms of potential energy through which energy may be conserved. It appears in electroanalytical chemistry and has industrial applications such as batteries and fuel cells. In biology, electrochemical gradients allow cells to control the direction ions move across membranes. In mitochondria and chloroplasts, proton gradients generate a chemiosmotic potential used to synthesize ATP, and the sodium-potassium gradient helps neural synapses quickly transmit information. An electrochemical gradient has two components: a differential concentration of electric charge across a membrane and a differential concentration of chemical species across that same membrane. In the former effect, the concentrated charge attracts charges of the opposite sign; in the latter, the concentrated species tends to diffuse across the membrane to an equalize concentrations. The combination of these two phenomena determines the thermodynamically-preferred direction for an ion's movement across the membrane.: 403 The combined
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effect can be quantified as a gradient in the thermodynamic electrochemical potential: ∇ μ ¯ i = ∇ μ i ( r → ) + z i F ∇ φ ( r → ) , {\displaystyle \nabla {\overline {\mu }}_{i}=\nabla \mu _{i}({\vec {r}})+z_{i}\mathrm {F} \nabla \varphi ({\vec {r}}){\text{,}}} with μi the chemical potential of the ion species i zi the charge per ion of the species i F, Faraday constant (the electrochemical potential is implicitly measured on a per-mole basis) φ, the local electric potential. Sometimes, the term "electrochemical potential" is abused to describe the electric potential generated by an ionic concentration gradient; that is, φ. An electrochemical gradient is analogous to the water pressure across a hydroelectric dam. Routes unblocked by the membrane (e.g. membrane transport protein or electrodes) correspond to turbines that convert the water's potential energy to other forms of physical or chemical energy, and the ions that pass through the membrane correspond to water traveling into the lower river. Conversely, energy can be used to pump water up into the lake above the dam, and chemical energy can be used to create electrochemical gradients. == Chemistry == The term typically applies in electrochemistry, when electrical energy in the form of an applied voltage is used to modulate the thermodynamic favorability of a chemical reaction. In a battery, an electrochemical potential arising from the movement of ions balances the reaction energy of the electrodes. The maximum voltage that a battery reaction can produce is sometimes called the standard electrochemical potential of that reaction. == Biological context == The generation of a transmembrane electrical potential through ion movement across a cell membrane drives biological processes like nerve conduction, muscle contraction, hormone secretion, and sensation. By convention, physiological voltages are measured relative to the extracellular region; a typical animal
|
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cell has an internal electrical potential of (−70)–(−50) mV.: 464 An electrochemical gradient is essential to mitochondrial oxidative phosphorylation. The final step of cellular respiration is the electron transport chain, composed of four complexes embedded in the inner mitochondrial membrane. Complexes I, III, and IV pump protons from the matrix to the intermembrane space (IMS); for every electron pair entering the chain, ten protons translocate into the IMS. The result is an electric potential of more than 200 mV. The energy resulting from the flux of protons back into the matrix is used by ATP synthase to combine inorganic phosphate and ADP.: 743–745 Similar to the electron transport chain, the light-dependent reactions of photosynthesis pump protons into the thylakoid lumen of chloroplasts to drive the synthesis of ATP. The proton gradient can be generated through either noncyclic or cyclic photophosphorylation. Of the proteins that participate in noncyclic photophosphorylation, photosystem II (PSII), plastiquinone, and cytochrome b6f complex directly contribute to generating the proton gradient. For each four photons absorbed by PSII, eight protons are pumped into the lumen.: 769–770 Several other transporters and ion channels play a role in generating a proton electrochemical gradient. One is TPK3, a potassium channel that is activated by Ca2+ and conducts K+ from the thylakoid lumen to the stroma, which helps establish the electric field. On the other hand, the electro-neutral K+ efflux antiporter (KEA3) transports K+ into the thylakoid lumen and H+ into the stroma, which helps establish the pH gradient. == Ion gradients == Since the ions are charged, they cannot pass through cellular membranes via simple diffusion. Two different mechanisms can transport the ions across the membrane: active or passive transport. An example of active transport of ions is the Na+-K+-ATPase (NKA). NKA is powered by the hydrolysis of ATP into ADP
|
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and an inorganic phosphate; for every molecule of ATP hydrolized, three Na+ are transported outside and two K+ are transported inside the cell. This makes the inside of the cell more negative than the outside and more specifically generates a membrane potential Vmembrane of about −60 mV. An example of passive transport is ion fluxes through Na+, K+, Ca2+, and Cl− channels. Unlike active transport, passive transport is powered by the arithmetic sum of osmosis (a concentration gradient) and an electric field (the transmembrane potential). Formally, the molar Gibbs free energy change associated with successful transport is Δ G = R T ln ( c i n c o u t ) + ( F z ) V m e m b r a n e {\displaystyle \Delta G=RT\ln {\!\left({\frac {c_{\rm {in}}}{c_{\rm {out}}}}\right)}+(Fz)V_{\rm {membrane}}} where R represents the gas constant, T represents absolute temperature, z is the charge per ion, and F represents the Faraday constant.: 464–465 In the example of Na+, both terms tend to support transport: the negative electric potential inside the cell attracts the positive ion and since Na+ is concentrated outside the cell, osmosis supports diffusion through the Na+ channel into the cell. In the case of K+, the effect of osmosis is reversed: although external ions are attracted by the negative intracellular potential, entropy seeks to diffuse the ions already concentrated inside the cell. The converse phenomenon (osmosis supports transport, electric potential opposes it) can be achieved for Na+ in cells with abnormal transmembrane potentials: at +70 mV, the Na+ influx halts; at higher potentials, it becomes an efflux. == Proton gradients == Proton gradients in particular are important in many types of cells as a form of energy storage. The gradient is usually used to drive ATP synthase, flagellar rotation, or metabolite transport.
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This section will focus on three processes that help establish proton gradients in their respective cells: bacteriorhodopsin and noncyclic photophosphorylation and oxidative phosphorylation. === Bacteriorhodopsin === The way bacteriorhodopsin generates a proton gradient in Archaea is through a proton pump. The proton pump relies on proton carriers to drive protons from the side of the membrane with a low H+ concentration to the side of the membrane with a high H+ concentration. In bacteriorhodopsin, the proton pump is activated by absorption of photons of 568nm wavelength, which leads to isomerization of the Schiff base (SB) in retinal forming the K state. This moves SB away from Asp85 and Asp212, causing H+ transfer from the SB to Asp85 forming the M1 state. The protein then shifts to the M2 state by separating Glu204 from Glu194 which releases a proton from Glu204 into the external medium. The SB is reprotonated by Asp96 which forms the N state. It is important that the second proton comes from Asp96 since its deprotonated state is unstable and rapidly reprotonated with a proton from the cytosol. The protonation of Asp85 and Asp96 causes re-isomerization of the SB, forming the O state. Finally, bacteriorhodopsin returns to its resting state when Asp85 releases its proton to Glu204. === Photophosphorylation === PSII also relies on light to drive the formation of proton gradients in chloroplasts, however, PSII utilizes vectorial redox chemistry to achieve this goal. Rather than physically transporting protons through the protein, reactions requiring the binding of protons will occur on the extracellular side while reactions requiring the release of protons will occur on the intracellular side. Absorption of photons of 680nm wavelength is used to excite two electrons in P680 to a higher energy level. These higher energy electrons are transferred to protein-bound plastoquinone (PQA) and then
|
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to unbound plastoquinone (PQB). This reduces plastoquinone (PQ) to plastoquinol (PQH2) which is released from PSII after gaining two protons from the stroma. The electrons in P680 are replenished by oxidizing water through the oxygen-evolving complex (OEC). This results in release of O2 and H+ into the lumen, for a total reaction of After being released from PSII, PQH2 travels to the cytochrome b6f complex, which then transfers two electrons from PQH2 to plastocyanin in two separate reactions. The process that occurs is similar to the Q-cycle in Complex III of the electron transport chain. In the first reaction, PQH2 binds to the complex on the lumen side and one electron is transferred to the iron-sulfur center which then transfers it to cytochrome f which then transfers it to plastocyanin. The second electron is transferred to heme bL which then transfers it to heme bH which then transfers it to PQ. In the second reaction, a second PQH2 gets oxidized, adding an electron to another plastocyanin and PQ. Both reactions together transfer four protons into the lumen.: 782–783 === Oxidative phosphorylation === Main article: Oxidative phosphorylation In the electron transport chain, complex I (CI) catalyzes the reduction of ubiquinone (UQ) to ubiquinol (UQH2) by the transfer of two electrons from reduced nicotinamide adenine dinucleotide (NADH) which translocates four protons from the mitochondrial matrix to the IMS: NADH + H + + UQ + 4 H + ⏟ m a t r i x ⟶ NAD + + UQH 2 + 4 H + ⏟ I M S {\displaystyle {\ce {NADH}}+{\ce {H^+}}+{\ce {UQ}}+4\underbrace {{\ce {H^+}}} _{\mathrm {matrix} }\longrightarrow {\ce {NAD^+}}+{\ce {UQH_2}}+4\underbrace {{\ce {H^+}}} _{\mathrm {IMS} }} Complex III (CIII) catalyzes the Q-cycle. The first step involving the transfer of two electrons from the UQH2 reduced by CI to two molecules of
|
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oxidized cytochrome c at the Qo site. In the second step, two more electrons reduce UQ to UQH2 at the Qi site. The total reaction is: 2 cytochrome c ⏟ oxidized + UQH 2 + 2 H + ⏟ matrix ⟶ 2 cytochrome c ⏟ reduced + UQ + 4 H + ⏟ IMS {\displaystyle 2\underbrace {\text{cytochrome c}} _{\text{oxidized}}+{\ce {UQH_2}}+2\underbrace {{\ce {H^+}}} _{\text{matrix}}\longrightarrow 2\underbrace {\text{cytochrome c}} _{\text{reduced}}+{\ce {UQ}}+4\underbrace {{\ce {H^+}}} _{\text{IMS}}} Complex IV (CIV) catalyzes the transfer of two electrons from the cytochrome c reduced by CIII to one half of a full oxygen. Utilizing one full oxygen in oxidative phosphorylation requires the transfer of four electrons. The oxygen will then consume four protons from the matrix to form water while another four protons are pumped into the IMS, to give a total reaction 2 cytochrome c ( reduced ) + 4 H + ( matrix ) + 1 2 O 2 ⟶ 2 cytochrome c ( oxidized ) + 2 H + ( IMS ) + H 2 O {\displaystyle 2{\text{cytochrome c}}({\text{reduced}})+4{\ce {H+}}({\text{matrix}})+{\frac {1}{2}}{\ce {O2}}\longrightarrow 2{\text{cytochrome c}}({\text{oxidized}})+2{\ce {H+}}({\text{IMS}})+{\ce {H2O}}} == See also == == References == Campbell & Reece (2005). Biology. Pearson Benjamin Cummings. ISBN 978-0-8053-7146-8. Stephen T. Abedon, "Important words and concepts from Chapter 8, Campbell & Reece, 2002 (1/14/2005)", for Biology 113 at the Ohio State University
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}
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Cortical thymic epithelial cells (cTECs) form unique parenchyma cell population of the thymus which critically contribute to the development of T cells. Thymus tissue is compartmentalized into cortex and medulla and each of these two compartments comprises its specific thymic epithelial cell subset. cTECs reside in the outer part- cortex, which mostly serves as a developmental site for T cells. Precursors of T cells originate in the bone marrow from which they migrate via bloodstream into thymic cortex, where they encounter stromal cells including cTECs, which form the microenvironment crucial for proliferation and development of T cells by expression of DLL4 (delta-like notch ligand 4), cytokines IL-7, TGFβ or stem cell factor and chemokines CCL25, CXCL12 or CCRL1 etc. Essential part of T cell development forms process called VDJ recombination, mediated by RAG recombinases, that stochastically changes DNA sequences of T cell receptors (TCR) and endows them with diverse recognition specificity. Thanks to this process, T cells can recognize vast repertoire of pathogens, but also self-peptides or even their TCRs don't respond to any surrounding signals. Major role of thymic epithelial cells is to test, whether TCRs are "functional" and on the other hand "harmless" to our body. While cTECs control the functionality of TCRs during the process called positive selection, Medullary thymic epithelial cells (mTECs) that home in the inner part of the thymus- medulla, present on their MHC molecules self-peptides, generated mostly by protein Autoimmune regulator, to eliminate T cells with self-reactive TCRs via processes of central tolerance e.g. negative selection and protect the body against development of autoimmunity. == Positive selection of T cells == Major function of cTECs is to positively select those T cells that are capable to recognize and interact with MHC molecules on their surface . Once T cell precursors enter the thymic
|
{
"page_id": 58068464,
"source": null,
"title": "Cortical thymic epithelial cells"
}
|
cortex, they start their transformation from double negative stages (T cell without surface expression of CD4 and CD8 co-receptors) to a double positive stage (T cell with surface expression of both co-receptors) that expresses fully recombined TCR. This stage undergoes above mentioned selection process. === Double positive–single positive transition === Interaction between TCR of double positive T cell and MHC I molecule leads to loss of CD4 expression and double positive T cell becomes CD8 single positive T cell, conversely, engagement of MHC II molecule leads to the development into CD4 single positive T cell. It was also described that CD8/CD4 restriction is influenced by transcription factors Runx3, in the case of CD8 restriction, and Th-POK which directs the development into CD4 T cell lineage and represses the expression of Runx3. More than 90% of double positive T cells are unable to reach this interaction and they die by neglect. === Cortex–medulla migration === Besides double positive-single positive transition, TCR-MHC interaction also triggers the expression of CCR7, chemokine receptor which recognizes chemokines CCL19 and CCL21, that are largely produced by mTECs in the medulla, and positively selected T cells start to migrate to medulla via their gradient. == Unique proteolytic pathways == It is incompletely understood whether presence of peptide ligands on MHC molecules of cTECs plays some role in positive selection. But it is likely that these peptide-MHC complexes are unique and different from self-peptides presented by mTECs, since cTECs developed unique proteolytic pathways. Indeed, there is slight evidence focused on unique cTEC peptide ligands, nevertheless, its more systematic characterization is still required. === Thymoproteasome (β5t) === Enzymatic machinery for MHC I antigen processing and presentation in cTECs involves thymoproteasome, which is defined by the presence of β5t subunit encoded by Psmb11 gene. Knockout of this gene revealed only
|
{
"page_id": 58068464,
"source": null,
"title": "Cortical thymic epithelial cells"
}
|
slight reduction in positive selection of CD8 T cells, but TCR repertoire of these cells was shown to be limited and they revealed impaired immunological properties e.g. bad antigen responsiveness and failure to maintain naive population in the periphery. β5t subunit was shown to reduce chymotrypsin-like activity of thymoproteasomes, resulting in generation of low affinity peptides. Such finding was confirmed by study that was focused on properties of thymoproteasome- chopped peptides. Importantly, low affinity interactions are considered to result in positive selection, whereas high affinity interactions are typical for negative selection and interaction with mTECs. === Cathepsin L === MHC II processing and presentation in cTECs took advantage of several proteolytic pathways including cathepsin L, encoded by Ctsl gene. Cathepsin S which is produced by most of the antigen- presenting cells along with mTECs is absent in cTECs. Cathepsin L not only cleaves invariant chain as other cathepsins, nevertheless was shown to cleave peptides for MHC II presentation and enlarge the pool of cTEC unique peptide ligands. Ctsl knockout mouse revealed severe reduction in frequency and repertoire of CD4 T cells and impairment of invariant chain degradation. Another study revealed that reduction of T cell repertoire wasn't caused by absence of invariant chain degradation, rather due to alterations in repertoire of cathepsin L cleaved peptides. === Thymus specific serine protease === Thymus specific serine protease is another cTEC specific enzyme, encoded by Prss16 gene, which is also involved in MHC II peptide processing. Prss16 knockout mice revealed reduced repertoire of positively selected CD4 T cells. === Macroautophagy === Common feature of cTECs and mTECs is constitutive macroautophagy. This process involves engulfment of portion of cytoplasm that contains organelles and vesicles into autophagosome that fuses with late endosomes or lysosomes and its content is chopped to small peptides. cTECs and mTECs
|
{
"page_id": 58068464,
"source": null,
"title": "Cortical thymic epithelial cells"
}
|
utilize this endogenous pathway for MHC II presentation during selection processes, instead of common loading of exogenous peptides. Mouse with deficient macroautophagy, specifically in the thymus, revealed reduced numbers and repertoire of CD4 T cells. == Development == cTECs and mTECs originate from endoderm, more specifically from the third pharyngeal pouch and it has been shown that they share common progenitor cell. Importantly, mTECs during their development possess classical markers of cTECs including CD205 and β5t which are completely absent in mature mTECs, suggesting another possible cTEC function, namely they might serve as a progenitor cell reservoir for mTECs. Indeed, several lineage tracing studies confirmed that cTEC progenitors or even mature cTECs are capable to give rise to mTECs. Nevertheless, there is available series of publications which suggests different mTEC progenitor pools or even argue that cTECs and mTECs reveal distinct unipotent progenitor cells. == References ==
|
{
"page_id": 58068464,
"source": null,
"title": "Cortical thymic epithelial cells"
}
|
Prior to 2013 the Forestry Commission managed about one million hectares of land across Great Britain, including 660,000 hectares of forest in Scotland, 250,000 hectares in England and 126,000 hectares in Wales. In 2013 the Commission's forests in Wales were transferred to Natural Resources Wales, whilst Forestry and Land Scotland was established in Scotland in 2019 to own and manage Scotland's National Forest Estate. These forests range from small scale urban forests to many of the largest forests in Britain. The Forestry Commission was set up in 1919 to carry out afforestation programmes across Britain for timber production. It is also responsible for maintaining and developing recreational facilities within the forests in England. == Forests in England == == Forests in Scotland == Since 2019 the National Forest Estate in Scotland has been managed by Forestry and Land Scotland and the table below may not be up to date. == Forests in Wales == Since 2013 the Public Forest Estate in Wales has been managed by Natural Resources Wales and the table below may not be up to date. == References == == See also == Forestry Commission List of Forestry Commission land on the Isle of Wight
|
{
"page_id": 36244978,
"source": null,
"title": "List of forests managed by the Forestry Commission"
}
|
This is a list of smoked foods. Smoking is the process of flavoring, cooking, or preserving food by exposing it to smoke from burning or smoldering material, most often wood. Foods have been smoked by humans throughout history. Meats and fish are the most common smoked foods, though cheeses, vegetables, and ingredients used to make beverages such as whisky, smoked beer, and lapsang souchong tea are also smoked. Smoked beverages are also included in this list. == Smoked foods == === Beverages === Lapsang souchong – a kind of tea. Mattha – an Indian buttermilk or yogurt drink that is sometimes smoked. Smoked beer – beer with a distinctive smoke flavor imparted by using malted barley dried over an open flame Grätzer. Suanmeitang – a Chinese smoked plum drink. Scotch Whisky – some scotch is made from grains that have been smoked over a peat fire. Smoked beverages === Cheeses === Smoked cheese is any cheese that has been specially treated by smoke-curing. It typically has a yellowish-brown outer pellicle which is a result of this curing process. Ardrahan Cheese – company that produces a smoked variety of their Ardrahan cheese. Bandel cheese Brânză de coșuleț Chechil Cheddar cheese – some versions are smoked Circassian smoked cheese Corleggy Cheese – company that produces some versions of smoked cheese, such as their Corleggy, Drumlin and Creeny varieties Gamonéu cheese Gouda cheese Burren Gold Gubbeen Farmhouse Cheese Idiazabal cheese Korbáčik – type of string cheese made from steamed cheese interwoven into fine braids. Common flavors include salty, smoked and garlic. Kwaito cheese Lincolnshire Poacher cheese Metsovone – produced by the Aromanians in Greece, has been a European protected designation of origin since 1996 Mozzarella – mozzarella affumicata is a term for the smoked variety Oscypek – smoked sheep milk cheese, made exclusively
|
{
"page_id": 42208759,
"source": null,
"title": "List of smoked foods"
}
|
in the Tatra Mountains region of Poland Oštiepok Palmero cheese Parenica – traditional Slovakian cheese; a semi-firm, non-ripening, semi-fat, steamed and usually smoked cheese, although the non-smoked version is also produced Provolone – some versions are smoked Pule cheese – reportedly the "world's most expensive cheese" priced at 1,000 Euros per kilogram; a smoked cheese made from the milk of Balkan donkeys from Serbia San Simón cheese Rauchkäse Ricotta Rygeost – traditional Danish cheese made from soured buttermilk smoked with straw and stinging nettles Scamorza Sulguni – traditional Georgian salted smoked cheese Tesyn Wensleydale cheese – produces Oak Smoked Wensleydale Smoked cheeses === Fish === Smoked fish is fish that has been cured by smoking. This was originally done as a preservative. African longfin eel – has fatty flesh which is prized in a smoked or jellied dish Arbroath smokie Atlantic mackerel Bokkoms Bonga shad Buckling Cakalang fufu – a smoked tuna dish of the Minahasan people of Indonesia Smoked catfish Caviar substitutes Lysekil Caviar – a paste made of smoked cod roe, canola oil, sugar, onion, tomato sauce and salt Smörgåskaviar – a Scandinavian smoked fish roe spread Cod Finnan haddie Goldeye Gwamegi – Korean style smoked half-dried fish Herring Bloater Blueback herring Craster kipper Kipper Katsuobushi – Japanese smoked and fermented skipjack tuna (bonito) Mullet Pudpod – Filipino smoked fish patty usually made from anchovies Saramură Sardine Scad Smoked salmon Lox Sprat Tinapa – native smoked fish delicacy in the Philippines Traditional Grimsby smoked fish Trout ==== Seafood ==== Smoked eel Smoked mussel Smoked oyster Smoked scallop === Meats === Smoked meat is a method of preparing red meat (and fish) which originates in prehistory. Its purpose is to preserve these protein-rich foods, which would otherwise spoil quickly, for long periods. There are two mechanisms for this preservation:
|
{
"page_id": 42208759,
"source": null,
"title": "List of smoked foods"
}
|
dehydration and the antibacterial properties of absorbed smoke. In modern days, the enhanced flavor of smoked foods makes them a delicacy in many cultures. Aliya - smoked dish originally from the Luo tribe of Kenya. Bacon – a meat product prepared from a pig and usually cured; some versions are also smoked for preservation or to add flavor Back bacon Baleron, Polish smoked pork neck cut Brési Burnt ends – flavorful pieces of meat cut from the point half of a smoked brisket Cecina – in Spanish, means "meat that has been salted and dried by means of air, sun or smoke" Charcuterie Chaudin Dutch loaf Elenski but Flurgönder – a smoked head cheese Gammon Grjúpán Hangikjöt Horse meat – a major meat in only a few countries, it is sometimes smoked Qarta – boiled and pan-fried horse rectum, it is sometimes smoked Zhal – a Kazakh cuisine dish of smoked horse neck lard Jeju Black pig Jerky Kassler Meatloaf Montreal-style smoked meat Pastrami Pickled pigs' feet Pig candy Pitina Pork jowl Oreilles de crisse Pork tail Rauchfleisch – German term for meat preserved by salting and cold smoking Salo Schäufele Se'i Smalahove Sopocka Speck Speck Alto Adige PGI Tyrolean Speck Suho meso Szalonna Turkey bacon Zhangcha duck ==== Hams ==== Ham Ammerländer Schinken – a type of dry-cured (and normally smoked) ham produced in the Ammerland area of North Germany. It has PGI status under EU law. Black Forest ham Christmas ham – some versions are smoked Country ham Ham hock Eisbein Stuffed ham Tasso ham Westphalia ham Smoked ham products ==== Sausages ==== Sausage is a food usually made from ground meat with a skin around it. Typically, a sausage is formed in a casing traditionally made from intestine, but sometimes synthetic. Sausage making is a traditional food
|
{
"page_id": 42208759,
"source": null,
"title": "List of smoked foods"
}
|
preservation technique. Sausages may be preserved by curing, drying, or smoking. Many types and varieties of sausages are smoked to help preserve them and to add flavor. Ahle Wurst – a hard pork sausage made in northern Hesse, Germany. Its name is a dialectal form of alte Wurst – "old sausage". Alheira Amsterdam ossenworst Andouille Bierwurst Bockwurst Bologna sausage and barbecue bologna Boudin Breakfast sausage Cabanossi Chinese sausage – a generic term referring to the many different types of sausages originating in China Chorizo Ciauscolo Debrecener Embutido Farinheira Frankfurter Würstchen Half-smoke Hungarian sausages – The cuisine of Hungary produces a vast number of types of sausages. Isterband Kielbasa Knackwurst Knipp Kochwurst Kohlwurst Krakowska Kulen Lebanon bologna Linguiça Liverwurst Braunschweiger Loukaniko Lukanka Lucanica Mettwurst Morteau sausage Nădlac sausage Pinkel Rookworst Salami Skilandis Sremska kobasica Summer sausage Teewurst Vienna sausage Winter salami Smoked sausages === Spices === Liquid smoke Merkén Paprika Smoked salt Smoked spices === Other === Alinazik kebab – a Turkish smoked eggplant dish Baingan bharta – an Indian smoked eggplant dish Chipotle – smoke-dried jalapeño chili pepper popular in Mexico and the American Southwest Jallab – a Middle-Eastern fruit and rose syrup smoked with Arabic incense Smoked egg – smoked quail or other fowl eggs Smoked garlic – popular in several areas of the world Smoked plum – an East Asian smoked fruit also used to make the Korean medicinal tea, Jeho-tang == See also == === In cuisines === Naga cuisine Yamal cuisine – Hot smoked fish == References == Media related to Smoked food at Wikimedia Commons Media related to Smoked cheeses at Wikimedia Commons Media related to Smoked fish at Wikimedia Commons Media related to Smoked meat at Wikimedia Commons Media related to Smoking (cooking) at Wikimedia Commons
|
{
"page_id": 42208759,
"source": null,
"title": "List of smoked foods"
}
|
Effector cell peptidase receptor 1, also known as EPR1, is a withdrawn database record. This locus represents an antisense transcript of the survivin locus. This record was withdrawn in collaboration with HGNC. It was defined by L26245.1, which appears to be a cloning artifact (Zaman GJ, Conway EM (July 2000). "The elusive factor Xa receptor: failure to detect transcripts that correspond to the published sequence of EPR-1". Blood. 96 (1): 145–8. doi:10.1182/blood.v96.1.145. PMID 10891443.).(This information come from https://www.ncbi.nlm.nih.gov/gene?term=L26245.1) == References == == Further reading ==
|
{
"page_id": 15076856,
"source": null,
"title": "EPR1"
}
|
A Universe of Consciousness: How Matter Becomes Imagination is the title of a 2000 book by biologists Gerald Maurice Edelman and Giulio Tononi; published in UK as Consciousness: How Matter Becomes Imagination. This book, written with Giulio Tononi, is the culmination of a series of works by Gerald Edelman on the workings of the brain which include Neural Darwinism and Bright Air, Brilliant Fire. == Precis == It is divided into six sections: the first three cover existing work from philosophical, neurological and Darwinian perspectives. Part IV presents the novel thesis of the work: the Dynamic Core Hypothesis. The remaining two parts explore how it resolves various philosophical and practical issues. === The Background === Since Descartes, philosophers have been occupied with the concept of consciousness and its subjective nature has posed a special problem for science. Its nature arises from the neuronal structures in the brain and some understanding of these, together with the experimental tools needed to explore them, is given in the following chapters. They then recapitulate Edelman's still controversial theory of somatic selectionism during early development which controls the topology of a particular brain and enables restructuring in response to experience. They argue that memory is not a symbolic representation but a reflection of how the brain has changed its dynamics in order to achieve motor activity. This leads to a discussion of primary consciousness which integrates with perception into a means of directing immediate behavior and requires significant levels of reentrancy to achieve its effects. === The Dynamic Core Hypothesis === The problem of integrating, or binding, the activity of functionally segregated areas of the brain in order to concentrate attention on a particular activity in a short amount of time (typically 100-250 msecs) after the presentation of a stimulus is explored by means of
|
{
"page_id": 1379832,
"source": null,
"title": "A Universe of Consciousness"
}
|
large-scale simulations. It is shown that this can only happen if some elements interact more strongly among themselves than with the rest of the system including a large amount of reentrancy. These functional clusters are only slowly coming into the range of PET or fMRI scanning technology which commonly require much longer time scales. At any given time, only a small subset of the neuronal groups in the brain are contributing directly to consciousness and this cluster is called a dynamic core. It represents a single point of view and each different state of consciousness corresponds to a different subset. Some dissociative disorders such as schizophrenia may result in the formation of multiple cores. === Implications of the hypothesis === One of the recurring issues in consciousness is the existence of qualia, such as redness, warmth and pain. It is not enough to identify each quale with a particular neuron or neuronal group; what is crucial is all the other groups which are highly influenced by the sensation and will fire at the same time. Thus each conscious state deserves to be called a quale. A small perturbation of a group of neurons can affect the whole in a very short space of time provided the system is kept in a state of readiness by the thalamus. Primary consciousness can build up a bodily based reference space even before language and higher-order consciousness appear. There is a preliminary approach to the relationship between conscious and unconscious processes, including sensors and motors, because so little is known. The evolution of language centres in the brain leads to higher order consciousness which enhances subjective experience and enables humans to describe qualia which are however experienced by a much wider range of animals. Thinking in humans has a range of representations—including pictorial. In
|
{
"page_id": 1379832,
"source": null,
"title": "A Universe of Consciousness"
}
|
contrast to computers which are Turing machines, brains are based on neuronal group selection. == Reviews == John Cornwell (Sunday Times) One of the most thoughtful books on the topic... While revealing much that is surprising about consciousness, they confirm some deeply held convictions about the power and mystery of human imagination. The results of this pioneering work challenge the conventional wisdom about consciousness. == See also == Wider than the Sky: The Phenomenal Gift of Consciousness, a similar 2004 book by Edelman == References ==
|
{
"page_id": 1379832,
"source": null,
"title": "A Universe of Consciousness"
}
|
The ethmoidal infundibulum is a funnel-shaped/slit-like: 690 /curved opening/passage/space: 690 /cleft upon the anterosuperior portion of the middle nasal meatus (and thus of the lateral wall of the nasal cavity) at the hiatus semilunaris (which represents the medial extremity of the infundibulum). The anterior ethmoidal air cells,: 612 and (usually: 612, 690 ) the frontonasal duct (which drains the frontal sinus): 690 open into the ethmoidal infundibulum. The ethmoidal infundibulum extends anterosuperiorly from its opening into the nasal cavity.: 612 == Anatomy == The ethmoidal infundibulum is bordered medially by the uncinate process of the ethmoid bone, and laterally by the orbital plate of the ethmoid bone. The ethmoid infundibulum leads towards the maxillary hiatus.: 690 The anterior ethmoidal cells open into the anterior part of the infundibulum. === Variation === The frontonasal duct may or may not drain into the ethmoidal infundibulum - this is determined by the place of attachment of the uncinate process of the ethmoid bone: if the uncinate process is attached to the lateral nasal wall, the frontonasal duct will open directly into the middle nasal meatus; if otherwise, it will drain into the infundibulum.: 690 In slightly over 50% of subjects, it is directly continuous with the frontonasal duct. When the anterior end of the uncinate process fuses with the anterior part of the bulla, however, this continuity is interrupted and the frontonasal duct then drains directly into the anterior end of the middle meatus. == References == == External links == Atlas image: rsa2p6 at the University of Michigan Health System
|
{
"page_id": 8654330,
"source": null,
"title": "Ethmoidal infundibulum"
}
|
Predatory dinoflagellates are predatory heterotrophic or mixotrophic alveolates that derive some or most of their nutrients from digesting other organisms. About one half of dinoflagellates lack photosynthetic pigments and specialize in consuming other eukaryotic cells, and even photosynthetic forms are often predatory. Organisms that derive their nutrition in this manner include Oxyrrhis marina, which feeds phagocytically on phytoplankton, Polykrikos kofoidii, which feeds on several species of red-tide and/or toxic dinoflagellates, Ceratium furca, which is primarily photosynthetic but also capable of ingesting other protists such as ciliates, Cochlodinium polykrikoides, which feeds on phytoplankton, Gambierdiscus toxicus, which feeds on algae and produces a toxin that causes ciguatera fish poisoning when ingested, and Pfiesteria and related species such as Luciella masanensis, which feed on diverse prey including fish skin and human blood cells. Predatory dinoflagellates can kill their prey by releasing toxins or phagocytize small prey directly. Some predatory algae have evolved extreme survival strategies. For example, Oxyrrhis marina can turn cannibalistic on its own species when no suitable non-self prey is available, and Pfiesteria and related species have been discovered to kill and feed on fish, and since have been (mistakenly) referred to as carnivorous "algae" by the media. == Pfiesteria hysteria == The media has applied the term carnivorous or predatory algae mainly to Pfiesteria piscicida, Pfiesteria shumwayae and other Pfiesteria-like dinoflagellates implicated in harmful algal blooms and fish kills. Pfiesteria is named after the American protistologist Lois Ann Pfiester. It is an ambush predator that utilizes a hit and run feeding strategy by releasing a toxin that paralyzes the respiratory systems of susceptible fish, such as menhaden, thus causing death by suffocation. It then consumes the tissue sloughed off its dead prey. Pfiesteria piscicida (Latin: fish killer) has been blamed for killing more than one billion fish in the Neuse
|
{
"page_id": 15076859,
"source": null,
"title": "Predatory dinoflagellate"
}
|
and Pamlico river estuaries in North Carolina and causing skin lesions in humans in the 1990s. It has been described as "skinning fish alive to feed on their flesh" or chemically sensing fish and producing lethal toxins to kill their prey and feed off the decaying remains. Its deadly nature has led to Pfiesteria being referred to as "killer algae" and has earned the organism the reputation as the "T. rex of the dinoflagellate world" or "the Cell from Hell." The prominent and exaggerating media coverage of Pfiesteria as carnivorous algae attacking fish and humans has been implicated in causing "Pfiesteria hysteria" in the Chesapeake Bay in 1997 resulting in an apparent outbreak of human illness in the Pocomoke region in Maryland. However, a study published the following year concluded the symptoms were unlikely to be caused by mass hysteria. == In popular culture == During the media coverage in the 1990s, Pfiesteria has been referred to as "super villain" and subsequently has been used as such in several fictional works. A Pfiesteria subspecies killing humans featured in James Powlik's 1999 environmental thriller Sea Change. In Frank Schätzing's 2004 science fiction novel The Swarm, lobsters and crabs spread the killer alga Pfiesteria homicida to humans. In Yann Martel's 2001 novel Life of Pi, the protagonist encounters a floating island of carnivorous algae inhabited by meerkats while shipwrecked in the Pacific Ocean. At a book reading in Calgary, Alberta, Canada, Martel explained that the carnivorous algae island had the purpose of representing the more fantastical of two competing stories in his novel and challenge the reader to a "leap of faith." In the 2005 National Geographic TV show Extraterrestrial, the alien organism termed Hysteria combines characteristics of Pfiesteria with those of cellular slime molds. Like Pfiesteria, Hysteria is a unicellular, microscopic
|
{
"page_id": 15076859,
"source": null,
"title": "Predatory dinoflagellate"
}
|
predator capable of producing a paralytic toxin. Like cellular slime molds, it can release chemical stress signals that cause the cells to aggregate into a swarm which allows the newly formed superorganism to feed on much larger animals and produce a fruiting body that releases spores for reproduction. == See also == Carnivorous fungus Carnivorous plant Protocarnivorous plant == References ==
|
{
"page_id": 15076859,
"source": null,
"title": "Predatory dinoflagellate"
}
|
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