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60,881,090 | https://en.wikipedia.org/wiki/Tidal%20strait | A tidal strait is a strait connecting two oceans or seas through which a tidal current flows. Tidal currents are usually unidirectional but sometimes are bidirectional. Tidal straits, though they are narrow seaways, are technically not rivers. They are frequently of tectonic origin. In them, currents develop because of elevation differences between the water basins at both ends.
Tides sometimes allow sediments to collect in tidal straits.
See also
Sediment trap (geology)
Tidal circularization
References
External links
A facies‐based depositional model for ancient and modern, tectonically–confined tidal straits
Deltas sourcing tidal straits: observations from some field case studies
Notes on shipwrecks in the Arthur Kill ship graveyard
Oceanography | Tidal strait | [
"Physics",
"Environmental_science"
] | 148 | [
"Oceanography",
"Hydrology",
"Applied and interdisciplinary physics"
] |
54,476,217 | https://en.wikipedia.org/wiki/NGC%207060 | NGC 7060 is an intermediate spiral galaxy located about 200 million light-years away in the constellation of Microscopium. The spiral arms of NGC 7060 appear to overlap. NGC 7060 was discovered by astronomer John Herschel on September 2, 1836.
NGC 7060 is the dominant member of a small group of galaxies known as the NGC 7060 group. Other members of the group are NGC 7057, NGC 7072, and NGC 7072A.
See also
List of NGC objects (7001–7840)
References
External links
Intermediate spiral galaxies
Microscopium
7060
66732
Astronomical objects discovered in 1836 | NGC 7060 | [
"Astronomy"
] | 130 | [
"Microscopium",
"Constellations"
] |
54,476,668 | https://en.wikipedia.org/wiki/Australian%20wormy%20chestnut | Australian wormy chestnut or firestreak is a common name for lumber of Eucalyptus obliqua, Eucalyptus sieberi and Eucalyptus fastigata grown in Victoria, southern New South Wales, and Tasmania in Australia. It is a hardwood species commonly used in flooring applications.
References
Trees of Australia
Eucalyptus
Wood
Plant common names | Australian wormy chestnut | [
"Biology"
] | 66 | [
"Plant common names",
"Common names of organisms",
"Plants"
] |
54,476,844 | https://en.wikipedia.org/wiki/Boolean%20algebra | In mathematics and mathematical logic, Boolean algebra is a branch of algebra. It differs from elementary algebra in two ways. First, the values of the variables are the truth values true and false, usually denoted 1 and 0, whereas in elementary algebra the values of the variables are numbers. Second, Boolean algebra uses logical operators such as conjunction (and) denoted as , disjunction (or) denoted as , and negation (not) denoted as . Elementary algebra, on the other hand, uses arithmetic operators such as addition, multiplication, subtraction, and division. Boolean algebra is therefore a formal way of describing logical operations in the same way that elementary algebra describes numerical operations.
Boolean algebra was introduced by George Boole in his first book The Mathematical Analysis of Logic (1847), and set forth more fully in his An Investigation of the Laws of Thought (1854). According to Huntington, the term Boolean algebra was first suggested by Henry M. Sheffer in 1913, although Charles Sanders Peirce gave the title "A Boolian Algebra with One Constant" to the first chapter of his "The Simplest Mathematics" in 1880. Boolean algebra has been fundamental in the development of digital electronics, and is provided for in all modern programming languages. It is also used in set theory and statistics.
History
A precursor of Boolean algebra was Gottfried Wilhelm Leibniz's algebra of concepts. The usage of binary in relation to the I Ching was central to Leibniz's characteristica universalis. It eventually created the foundations of algebra of concepts. Leibniz's algebra of concepts is deductively equivalent to the Boolean algebra of sets.
Boole's algebra predated the modern developments in abstract algebra and mathematical logic; it is however seen as connected to the origins of both fields. In an abstract setting, Boolean algebra was perfected in the late 19th century by Jevons, Schröder, Huntington and others, until it reached the modern conception of an (abstract) mathematical structure. For example, the empirical observation that one can manipulate expressions in the algebra of sets, by translating them into expressions in Boole's algebra, is explained in modern terms by saying that the algebra of sets is a Boolean algebra (note the indefinite article). In fact, M. H. Stone proved in 1936 that every Boolean algebra is isomorphic to a field of sets.
In the 1930s, while studying switching circuits, Claude Shannon observed that one could also apply the rules of Boole's algebra in this setting, and he introduced switching algebra as a way to analyze and design circuits by algebraic means in terms of logic gates. Shannon already had at his disposal the abstract mathematical apparatus, thus he cast his switching algebra as the two-element Boolean algebra. In modern circuit engineering settings, there is little need to consider other Boolean algebras, thus "switching algebra" and "Boolean algebra" are often used interchangeably.
Efficient implementation of Boolean functions is a fundamental problem in the design of combinational logic circuits. Modern electronic design automation tools for very-large-scale integration (VLSI) circuits often rely on an efficient representation of Boolean functions known as (reduced ordered) binary decision diagrams (BDD) for logic synthesis and formal verification.
Logic sentences that can be expressed in classical propositional calculus have an equivalent expression in Boolean algebra. Thus, Boolean logic is sometimes used to denote propositional calculus performed in this way. Boolean algebra is not sufficient to capture logic formulas using quantifiers, like those from first order logic.
Although the development of mathematical logic did not follow Boole's program, the connection between his algebra and logic was later put on firm ground in the setting of algebraic logic, which also studies the algebraic systems of many other logics. The problem of determining whether the variables of a given Boolean (propositional) formula can be assigned in such a way as to make the formula evaluate to true is called the Boolean satisfiability problem (SAT), and is of importance to theoretical computer science, being the first problem shown to be NP-complete. The closely related model of computation known as a Boolean circuit relates time complexity (of an algorithm) to circuit complexity.
Values
Whereas expressions denote mainly numbers in elementary algebra, in Boolean algebra, they denote the truth values false and true. These values are represented with the bits, 0 and 1. They do not behave like the integers 0 and 1, for which , but may be identified with the elements of the two-element field , that is, integer arithmetic modulo 2, for which . Addition and multiplication then play the Boolean roles of XOR (exclusive-or) and AND (conjunction), respectively, with disjunction (inclusive-or) definable as and negation as . In , may be replaced by , since they denote the same operation; however, this way of writing Boolean operations allows applying the usual arithmetic operations of integers (this may be useful when using a programming language in which is not implemented).
Boolean algebra also deals with functions which have their values in the set . A sequence of bits is a commonly used example of such a function. Another common example is the totality of subsets of a set : to a subset of , one can define the indicator function that takes the value on , and outside . The most general example is the set elements of a Boolean algebra, with all of the foregoing being instances thereof.
As with elementary algebra, the purely equational part of the theory may be developed, without considering explicit values for the variables.
Operations
Basic operations
While Elementary algebra has four operations (addition, subtraction, multiplication, and division), the Boolean algebra has only three basic operations: conjunction, disjunction, and negation, expressed with the corresponding binary operators AND () and OR () and the unary operator NOT (), collectively referred to as Boolean operators. Variables in Boolean algebra that store the logical value of 0 and 1 are called the Boolean variables. They are used to store either true or false values. The basic operations on Boolean variables x and y are defined as follows:
{| class="wikitable" style="text-align: center"
|-
!Logical operation
!Operator
!Notation
!Alternative notations
!Definition
|-
|Conjunction
|AND
|
|
|
|-
|Disjunction
|OR
|
|
|
|-
|Negation
|NOT
|¬x
|{{math|NOT x, Nx, x̅, x, !x}}
|
|}
Alternatively, the values of , , and ¬x can be expressed by tabulating their values with truth tables as follows:
When used in expressions, the operators are applied according to the precedence rules. As with elementary algebra, expressions in parentheses are evaluated first, following the precedence rules.
If the truth values 0 and 1 are interpreted as integers, these operations may be expressed with the ordinary operations of arithmetic (where x + y uses addition and xy uses multiplication), or by the minimum/maximum functions:
One might consider that only negation and one of the two other operations are basic because of the following identities that allow one to define conjunction in terms of negation and the disjunction, and vice versa (De Morgan's laws):
Secondary operations
Operations composed from the basic operations include, among others, the following:
These definitions give rise to the following truth tables giving the values of these operations for all four possible inputs.
{| class="wikitable" style="text-align: center"
|+Secondary operations. Table 1
|-
!
!
!
!
!
|-
!0
!0
| 1 || 0 || 1
|-
!1
!0
|0 || 1 || 0
|-
!0
!1
|1 || 1 || 0
|-
!1
!1
| 1 || 0 || 1
|}
Material conditional The first operation, x → y, or Cxy, is called material implication. If x is true, then the result of expression x → y is taken to be that of y (e.g. if x is true and y is false, then x → y is also false). But if x is false, then the value of y can be ignored; however, the operation must return some Boolean value and there are only two choices. So by definition, x → y is true when x is false (relevance logic rejects this definition, by viewing an implication with a false premise as something other than either true or false).
Exclusive OR (XOR)
The second operation, x ⊕ y, or Jxy, is called exclusive or (often abbreviated as XOR) to distinguish it from disjunction as the inclusive kind. It excludes the possibility of both x and y being true (e.g. see table): if both are true then result is false. Defined in terms of arithmetic it is addition where mod 2 is 1 + 1 = 0.
Logical equivalence The third operation, the complement of exclusive or, is equivalence or Boolean equality: x ≡ y, or Exy, is true just when x and y have the same value. Hence x ⊕ y as its complement can be understood as x ≠ y, being true just when x and y are different. Thus, its counterpart in arithmetic mod 2 is x + y. Equivalence's counterpart in arithmetic mod 2 is x + y + 1.
Laws
A law of Boolean algebra is an identity such as between two Boolean terms, where a Boolean term is defined as an expression built up from variables and the constants 0 and 1 using the operations ∧, ∨, and ¬. The concept can be extended to terms involving other Boolean operations such as ⊕, →, and ≡, but such extensions are unnecessary for the purposes to which the laws are put. Such purposes include the definition of a Boolean algebra as any model of the Boolean laws, and as a means for deriving new laws from old as in the derivation of from (as treated in ).
Monotone laws
Boolean algebra satisfies many of the same laws as ordinary algebra when one matches up ∨ with addition and ∧ with multiplication. In particular the following laws are common to both kinds of algebra:
{|
|-
| Associativity of : ||style="width:2em"| ||style="text-align: right"| ||
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| Associativity of : || ||style="text-align: right"| ||
|-
| Commutativity of : || ||style="text-align: right"| ||
|-
| Commutativity of : || ||style="text-align: right"| ||
|-
| Distributivity of over : || ||style="text-align: right"| ||
|-
| Identity for : || ||style="text-align: right"| ||
|-
| Identity for : || ||style="text-align: right"| ||
|-
| Annihilator for : || ||style="text-align: right"| ||
|-
|}
The following laws hold in Boolean algebra, but not in ordinary algebra:
{|
|- Annihilator for : || ||style="text-align: right"| ||
|-
|Annihilator for : || ||style="text-align: right"|
|
|-
| Idempotence of : || ||style="text-align: right"| ||
|-
| Idempotence of : || ||style="text-align: right"| ||
|-
| Absorption 1: || ||style="text-align: right"| ||
|-
| Absorption 2: || ||style="text-align: right"| ||
|-
|Distributivity of over :
|
|
|
|-
| Distributivity of over : |
|}
Taking in the third law above shows that it is not an ordinary algebra law, since . The remaining five laws can be falsified in ordinary algebra by taking all variables to be 1. For example, in absorption law 1, the left hand side would be , while the right hand side would be 1 (and so on).
All of the laws treated thus far have been for conjunction and disjunction. These operations have the property that changing either argument either leaves the output unchanged, or the output changes in the same way as the input. Equivalently, changing any variable from 0 to 1 never results in the output changing from 1 to 0. Operations with this property are said to be monotone. Thus the axioms thus far have all been for monotonic Boolean logic. Nonmonotonicity enters via complement ¬ as follows.
Nonmonotone laws
The complement operation is defined by the following two laws.
All properties of negation including the laws below follow from the above two laws alone.
In both ordinary and Boolean algebra, negation works by exchanging pairs of elements, hence in both algebras it satisfies the double negation law (also called involution law)
But whereas ordinary algebra satisfies the two laws
Boolean algebra satisfies De Morgan's laws:
Completeness
The laws listed above define Boolean algebra, in the sense that they entail the rest of the subject. The laws complementation 1 and 2, together with the monotone laws, suffice for this purpose and can therefore be taken as one possible complete set of laws or axiomatization of Boolean algebra. Every law of Boolean algebra follows logically from these axioms. Furthermore, Boolean algebras can then be defined as the models of these axioms as treated in .
Writing down further laws of Boolean algebra cannot give rise to any new consequences of these axioms, nor can it rule out any model of them. In contrast, in a list of some but not all of the same laws, there could have been Boolean laws that did not follow from those on the list, and moreover there would have been models of the listed laws that were not Boolean algebras.
This axiomatization is by no means the only one, or even necessarily the most natural given that attention was not paid as to whether some of the axioms followed from others, but there was simply a choice to stop when enough laws had been noticed, treated further in . Or the intermediate notion of axiom can be sidestepped altogether by defining a Boolean law directly as any tautology, understood as an equation that holds for all values of its variables over 0 and 1. All these definitions of Boolean algebra can be shown to be equivalent.
Duality principle
Principle: If {X, R} is a partially ordered set, then {X, R(inverse)} is also a partially ordered set.
There is nothing special about the choice of symbols for the values of Boolean algebra. 0 and 1 could be renamed to α and β, and as long as it was done consistently throughout, it would still be Boolean algebra, albeit with some obvious cosmetic differences.
But suppose 0 and 1 were renamed 1 and 0 respectively. Then it would still be Boolean algebra, and moreover operating on the same values. However, it would not be identical to our original Boolean algebra because now ∨ behaves the way ∧ used to do and vice versa. So there are still some cosmetic differences to show that the notation has been changed, despite the fact that 0s and 1s are still being used.
But if in addition to interchanging the names of the values, the names of the two binary operations are also interchanged, now there is no trace of what was done. The end product is completely indistinguishable from what was started with. The columns for and in the truth tables have changed places, but that switch is immaterial.
When values and operations can be paired up in a way that leaves everything important unchanged when all pairs are switched simultaneously, the members of each pair are called dual to each other. Thus 0 and 1 are dual, and ∧ and ∨ are dual. The duality principle, also called De Morgan duality, asserts that Boolean algebra is unchanged when all dual pairs are interchanged.
One change not needed to make as part of this interchange was to complement. Complement is a self-dual operation. The identity or do-nothing operation x (copy the input to the output) is also self-dual. A more complicated example of a self-dual operation is . There is no self-dual binary operation that depends on both its arguments. A composition of self-dual operations is a self-dual operation. For example, if , then is a self-dual operation of four arguments x, y, z, t.
The principle of duality can be explained from a group theory perspective by the fact that there are exactly four functions that are one-to-one mappings (automorphisms) of the set of Boolean polynomials back to itself: the identity function, the complement function, the dual function and the contradual function (complemented dual). These four functions form a group under function composition, isomorphic to the Klein four-group, acting on the set of Boolean polynomials. Walter Gottschalk remarked that consequently a more appropriate name for the phenomenon would be the principle (or square) of quaternality.
Diagrammatic representations
Venn diagrams
A Venn diagram can be used as a representation of a Boolean operation using shaded overlapping regions. There is one region for each variable, all circular in the examples here. The interior and exterior of region x corresponds respectively to the values 1 (true) and 0 (false) for variable x. The shading indicates the value of the operation for each combination of regions, with dark denoting 1 and light 0 (some authors use the opposite convention).
The three Venn diagrams in the figure below represent respectively conjunction , disjunction , and complement ¬x.
For conjunction, the region inside both circles is shaded to indicate that is 1 when both variables are 1. The other regions are left unshaded to indicate that is 0 for the other three combinations.
The second diagram represents disjunction by shading those regions that lie inside either or both circles. The third diagram represents complement ¬x by shading the region not inside the circle.
While we have not shown the Venn diagrams for the constants 0 and 1, they are trivial, being respectively a white box and a dark box, neither one containing a circle. However, we could put a circle for x in those boxes, in which case each would denote a function of one argument, x, which returns the same value independently of x, called a constant function. As far as their outputs are concerned, constants and constant functions are indistinguishable; the difference is that a constant takes no arguments, called a zeroary or nullary operation, while a constant function takes one argument, which it ignores, and is a unary operation.
Venn diagrams are helpful in visualizing laws. The commutativity laws for ∧ and ∨ can be seen from the symmetry of the diagrams: a binary operation that was not commutative would not have a symmetric diagram because interchanging x and y would have the effect of reflecting the diagram horizontally and any failure of commutativity would then appear as a failure of symmetry.
Idempotence of ∧ and ∨ can be visualized by sliding the two circles together and noting that the shaded area then becomes the whole circle, for both ∧ and ∨.
To see the first absorption law, , start with the diagram in the middle for x ∨ y and note that the portion of the shaded area in common with the x circle is the whole of the x circle. For the second absorption law, , start with the left diagram for and note that shading the whole of the x circle results in just the x circle being shaded, since the previous shading was inside the x circle.
The double negation law can be seen by complementing the shading in the third diagram for ¬x, which shades the x circle.
To visualize the first De Morgan's law, , start with the middle diagram for and complement its shading so that only the region outside both circles is shaded, which is what the right hand side of the law describes. The result is the same as if we shaded that region which is both outside the x circle and outside the y circle, i.e. the conjunction of their exteriors, which is what the left hand side of the law describes.
The second De Morgan's law, , works the same way with the two diagrams interchanged.
The first complement law, , says that the interior and exterior of the x circle have no overlap. The second complement law, , says that everything is either inside or outside the x circle.
Digital logic gates
Digital logic is the application of the Boolean algebra of 0 and 1 to electronic hardware consisting of logic gates connected to form a circuit diagram. Each gate implements a Boolean operation, and is depicted schematically by a shape indicating the operation. The shapes associated with the gates for conjunction (AND-gates), disjunction (OR-gates), and complement (inverters) are as follows:
The lines on the left of each gate represent input wires or ports. The value of the input is represented by a voltage on the lead. For so-called "active-high" logic, 0 is represented by a voltage close to zero or "ground," while 1 is represented by a voltage close to the supply voltage; active-low reverses this. The line on the right of each gate represents the output port, which normally follows the same voltage conventions as the input ports.
Complement is implemented with an inverter gate. The triangle denotes the operation that simply copies the input to the output; the small circle on the output denotes the actual inversion complementing the input. The convention of putting such a circle on any port means that the signal passing through this port is complemented on the way through, whether it is an input or output port.
The duality principle, or De Morgan's laws, can be understood as asserting that complementing all three ports of an AND gate converts it to an OR gate and vice versa, as shown in Figure 4 below. Complementing both ports of an inverter however leaves the operation unchanged.
More generally, one may complement any of the eight subsets of the three ports of either an AND or OR gate. The resulting sixteen possibilities give rise to only eight Boolean operations, namely those with an odd number of 1s in their truth table. There are eight such because the "odd-bit-out" can be either 0 or 1 and can go in any of four positions in the truth table. There being sixteen binary Boolean operations, this must leave eight operations with an even number of 1s in their truth tables. Two of these are the constants 0 and 1 (as binary operations that ignore both their inputs); four are the operations that depend nontrivially on exactly one of their two inputs, namely x, y, ¬x, and ¬y; and the remaining two are x ⊕ y (XOR) and its complement x ≡ y.
Boolean algebras
The term "algebra" denotes both a subject, namely the subject of algebra, and an object, namely an algebraic structure. Whereas the foregoing has addressed the subject of Boolean algebra, this section deals with mathematical objects called Boolean algebras, defined in full generality as any model of the Boolean laws. We begin with a special case of the notion definable without reference to the laws, namely concrete Boolean algebras, and then give the formal definition of the general notion.
Concrete Boolean algebras
A concrete Boolean algebra or field of sets is any nonempty set of subsets of a given set X closed under the set operations of union, intersection, and complement relative to X.
(Historically X itself was required to be nonempty as well to exclude the degenerate or one-element Boolean algebra, which is the one exception to the rule that all Boolean algebras satisfy the same equations since the degenerate algebra satisfies every equation. However, this exclusion conflicts with the preferred purely equational definition of "Boolean algebra", there being no way to rule out the one-element algebra using only equations— 0 ≠ 1 does not count, being a negated equation. Hence modern authors allow the degenerate Boolean algebra and let X be empty.)
Example 1. The power set 2X of X, consisting of all subsets of X. Here X may be any set: empty, finite, infinite, or even uncountable.
Example 2. The empty set and X. This two-element algebra shows that a concrete Boolean algebra can be finite even when it consists of subsets of an infinite set. It can be seen that every field of subsets of X must contain the empty set and X. Hence no smaller example is possible, other than the degenerate algebra obtained by taking X to be empty so as to make the empty set and X coincide.
Example 3. The set of finite and cofinite sets of integers, where a cofinite set is one omitting only finitely many integers. This is clearly closed under complement, and is closed under union because the union of a cofinite set with any set is cofinite, while the union of two finite sets is finite. Intersection behaves like union with "finite" and "cofinite" interchanged. This example is countably infinite because there are only countably many finite sets of integers.
Example 4. For a less trivial example of the point made by example 2, consider a Venn diagram formed by n closed curves partitioning the diagram into 2n regions, and let X be the (infinite) set of all points in the plane not on any curve but somewhere within the diagram. The interior of each region is thus an infinite subset of X, and every point in X is in exactly one region. Then the set of all 22n possible unions of regions (including the empty set obtained as the union of the empty set of regions and X obtained as the union of all 2n regions) is closed under union, intersection, and complement relative to X and therefore forms a concrete Boolean algebra. Again, there are finitely many subsets of an infinite set forming a concrete Boolean algebra, with example 2 arising as the case n = 0 of no curves.
Subsets as bit vectors
A subset Y of X can be identified with an indexed family of bits with index set X, with the bit indexed by being 1 or 0 according to whether or not . (This is the so-called characteristic function notion of a subset.) For example, a 32-bit computer word consists of 32 bits indexed by the set {0,1,2,...,31}, with 0 and 31 indexing the low and high order bits respectively. For a smaller example, if where are viewed as bit positions in that order from left to right, the eight subsets {}, {c}, {b}, {b,c}, {a}, {a,c}, {a,b}, and {a,b,c} of X can be identified with the respective bit vectors 000, 001, 010, 011, 100, 101, 110, and 111. Bit vectors indexed by the set of natural numbers are infinite sequences of bits, while those indexed by the reals in the unit interval [0,1] are packed too densely to be able to write conventionally but nonetheless form well-defined indexed families (imagine coloring every point of the interval [0,1] either black or white independently; the black points then form an arbitrary subset of [0,1]).
From this bit vector viewpoint, a concrete Boolean algebra can be defined equivalently as a nonempty set of bit vectors all of the same length (more generally, indexed by the same set) and closed under the bit vector operations of bitwise ∧, ∨, and ¬, as in , , and , the bit vector realizations of intersection, union, and complement respectively.
Prototypical Boolean algebra
The set {0,1} and its Boolean operations as treated above can be understood as the special case of bit vectors of length one, which by the identification of bit vectors with subsets can also be understood as the two subsets of a one-element set. This is called the prototypical Boolean algebra, justified by the following observation.
The laws satisfied by all nondegenerate concrete Boolean algebras coincide with those satisfied by the prototypical Boolean algebra.
This observation is proved as follows. Certainly any law satisfied by all concrete Boolean algebras is satisfied by the prototypical one since it is concrete. Conversely any law that fails for some concrete Boolean algebra must have failed at a particular bit position, in which case that position by itself furnishes a one-bit counterexample to that law. Nondegeneracy ensures the existence of at least one bit position because there is only one empty bit vector.
The final goal of the next section can be understood as eliminating "concrete" from the above observation. That goal is reached via the stronger observation that, up to isomorphism, all Boolean algebras are concrete.
Boolean algebras: the definition
The Boolean algebras so far have all been concrete, consisting of bit vectors or equivalently of subsets of some set. Such a Boolean algebra consists of a set and operations on that set which can be shown to satisfy the laws of Boolean algebra.
Instead of showing that the Boolean laws are satisfied, we can instead postulate a set X, two binary operations on X, and one unary operation, and require that those operations satisfy the laws of Boolean algebra. The elements of X need not be bit vectors or subsets but can be anything at all. This leads to the more general abstract definition.
A Boolean algebra is any set with binary operations ∧ and ∨ and a unary operation ¬ thereon satisfying the Boolean laws.
For the purposes of this definition it is irrelevant how the operations came to satisfy the laws, whether by fiat or proof. All concrete Boolean algebras satisfy the laws (by proof rather than fiat), whence every concrete Boolean algebra is a Boolean algebra according to our definitions. This axiomatic definition of a Boolean algebra as a set and certain operations satisfying certain laws or axioms by fiat is entirely analogous to the abstract definitions of group, ring, field etc. characteristic of modern or abstract algebra.
Given any complete axiomatization of Boolean algebra, such as the axioms for a complemented distributive lattice, a sufficient condition for an algebraic structure of this kind to satisfy all the Boolean laws is that it satisfy just those axioms. The following is therefore an equivalent definition.
A Boolean algebra is a complemented distributive lattice.
The section on axiomatization lists other axiomatizations, any of which can be made the basis of an equivalent definition.
Representable Boolean algebras
Although every concrete Boolean algebra is a Boolean algebra, not every Boolean algebra need be concrete. Let n be a square-free positive integer, one not divisible by the square of an integer, for example 30 but not 12. The operations of greatest common divisor, least common multiple, and division into n (that is, ¬x = n/x), can be shown to satisfy all the Boolean laws when their arguments range over the positive divisors of n. Hence those divisors form a Boolean algebra. These divisors are not subsets of a set, making the divisors of n a Boolean algebra that is not concrete according to our definitions.
However, if each divisor of n is represented by the set of its prime factors, this nonconcrete Boolean algebra is isomorphic to the concrete Boolean algebra consisting of all sets of prime factors of n, with union corresponding to least common multiple, intersection to greatest common divisor, and complement to division into n. So this example, while not technically concrete, is at least "morally" concrete via this representation, called an isomorphism. This example is an instance of the following notion.
A Boolean algebra is called representable when it is isomorphic to a concrete Boolean algebra.
The next question is answered positively as follows.
Every Boolean algebra is representable.
That is, up to isomorphism, abstract and concrete Boolean algebras are the same thing. This result depends on the Boolean prime ideal theorem, a choice principle slightly weaker than the axiom of choice. This strong relationship implies a weaker result strengthening the observation in the previous subsection to the following easy consequence of representability.
The laws satisfied by all Boolean algebras coincide with those satisfied by the prototypical Boolean algebra.
It is weaker in the sense that it does not of itself imply representability. Boolean algebras are special here, for example a relation algebra is a Boolean algebra with additional structure but it is not the case that every relation algebra is representable in the sense appropriate to relation algebras.
Axiomatizing Boolean algebra
The above definition of an abstract Boolean algebra as a set together with operations satisfying "the" Boolean laws raises the question of what those laws are. A simplistic answer is "all Boolean laws", which can be defined as all equations that hold for the Boolean algebra of 0 and 1. However, since there are infinitely many such laws, this is not a satisfactory answer in practice, leading to the question of it suffices to require only finitely many laws to hold.
In the case of Boolean algebras, the answer is "yes": the finitely many equations listed above are sufficient. Thus, Boolean algebra is said to be finitely axiomatizable or finitely based.
Moreover, the number of equations needed can be further reduced. To begin with, some of the above laws are implied by some of the others. A sufficient subset of the above laws consists of the pairs of associativity, commutativity, and absorption laws, distributivity of ∧ over ∨ (or the other distributivity law—one suffices), and the two complement laws. In fact, this is the traditional axiomatization of Boolean algebra as a complemented distributive lattice.
By introducing additional laws not listed above, it becomes possible to shorten the list of needed equations yet further; for instance, with the vertical bar representing the Sheffer stroke operation, the single axiom is sufficient to completely axiomatize Boolean algebra. It is also possible to find longer single axioms using more conventional operations; see Minimal axioms for Boolean algebra.
Propositional logic
Propositional logic is a logical system that is intimately connected to Boolean algebra. Many syntactic concepts of Boolean algebra carry over to propositional logic with only minor changes in notation and terminology, while the semantics of propositional logic are defined via Boolean algebras in a way that the tautologies (theorems) of propositional logic correspond to equational theorems of Boolean algebra.
Syntactically, every Boolean term corresponds to a propositional formula of propositional logic. In this translation between Boolean algebra and propositional logic, Boolean variables x, y, ... become propositional variables (or atoms) P, Q, ... Boolean terms such as x ∨ y become propositional formulas P ∨ Q; 0 becomes false or ⊥, and 1 becomes true or T'''. It is convenient when referring to generic propositions to use Greek letters Φ, Ψ, ... as metavariables (variables outside the language of propositional calculus, used when talking about propositional calculus) to denote propositions.
The semantics of propositional logic rely on truth assignments. The essential idea of a truth assignment is that the propositional variables are mapped to elements of a fixed Boolean algebra, and then the truth value of a propositional formula using these letters is the element of the Boolean algebra that is obtained by computing the value of the Boolean term corresponding to the formula. In classical semantics, only the two-element Boolean algebra is used, while in Boolean-valued semantics arbitrary Boolean algebras are considered. A tautology is a propositional formula that is assigned truth value 1 by every truth assignment of its propositional variables to an arbitrary Boolean algebra (or, equivalently, every truth assignment to the two element Boolean algebra).
These semantics permit a translation between tautologies of propositional logic and equational theorems of Boolean algebra. Every tautology Φ of propositional logic can be expressed as the Boolean equation Φ = 1, which will be a theorem of Boolean algebra. Conversely, every theorem Φ = Ψ of Boolean algebra corresponds to the tautologies (Φ ∨ ¬Ψ) ∧ (¬Φ ∨ Ψ) and (Φ ∧ Ψ) ∨ (¬Φ ∧ ¬Ψ). If → is in the language, these last tautologies can also be written as (Φ → Ψ) ∧ (Ψ → Φ), or as two separate theorems Φ → Ψ and Ψ → Φ; if ≡ is available, then the single tautology Φ ≡ Ψ can be used.
Applications
One motivating application of propositional calculus is the analysis of propositions and deductive arguments in natural language. Whereas the proposition "if x = 3, then x + 1 = 4" depends on the meanings of such symbols as + and 1, the proposition "if x = 3, then x = 3" does not; it is true merely by virtue of its structure, and remains true whether "x = 3" is replaced by "x = 4" or "the moon is made of green cheese." The generic or abstract form of this tautology is "if P, then P," or in the language of Boolean algebra, P → P.
Replacing P by x = 3 or any other proposition is called instantiation of P by that proposition. The result of instantiating P in an abstract proposition is called an instance of the proposition. Thus, x = 3 → x = 3 is a tautology by virtue of being an instance of the abstract tautology P → P. All occurrences of the instantiated variable must be instantiated with the same proposition, to avoid such nonsense as P → x = 3 or x = 3 → x = 4.
Propositional calculus restricts attention to abstract propositions, those built up from propositional variables using Boolean operations. Instantiation is still possible within propositional calculus, but only by instantiating propositional variables by abstract propositions, such as instantiating Q by Q → P in P → (Q → P) to yield the instance P → ((Q → P) → P).
(The availability of instantiation as part of the machinery of propositional calculus avoids the need for metavariables within the language of propositional calculus, since ordinary propositional variables can be considered within the language to denote arbitrary propositions. The metavariables themselves are outside the reach of instantiation, not being part of the language of propositional calculus but rather part of the same language for talking about it that this sentence is written in, where there is a need to be able to distinguish propositional variables and their instantiations as being distinct syntactic entities.)
Deductive systems for propositional logic
An axiomatization of propositional calculus is a set of tautologies called axioms and one or more inference rules for producing new tautologies from old. A proof in an axiom system A is a finite nonempty sequence of propositions each of which is either an instance of an axiom of A or follows by some rule of A from propositions appearing earlier in the proof (thereby disallowing circular reasoning). The last proposition is the theorem proved by the proof. Every nonempty initial segment of a proof is itself a proof, whence every proposition in a proof is itself a theorem. An axiomatization is sound when every theorem is a tautology, and complete when every tautology is a theorem.
Sequent calculus
Propositional calculus is commonly organized as a Hilbert system, whose operations are just those of Boolean algebra and whose theorems are Boolean tautologies, those Boolean terms equal to the Boolean constant 1. Another form is sequent calculus, which has two sorts, propositions as in ordinary propositional calculus, and pairs of lists of propositions called sequents, such as The two halves of a sequent are called the antecedent and the succedent respectively. The customary metavariable denoting an antecedent or part thereof is Γ, and for a succedent Δ; thus Γ, A ⊢ Δ would denote a sequent whose succedent is a list Δ and whose antecedent is a list Γ with an additional proposition A appended after it. The antecedent is interpreted as the conjunction of its propositions, the succedent as the disjunction of its propositions, and the sequent itself as the entailment of the succedent by the antecedent.
Entailment differs from implication in that whereas the latter is a binary operation that returns a value in a Boolean algebra, the former is a binary relation which either holds or does not hold. In this sense, entailment is an external form of implication, meaning external to the Boolean algebra, thinking of the reader of the sequent as also being external and interpreting and comparing antecedents and succedents in some Boolean algebra. The natural interpretation of ⊢ is as ≤ in the partial order of the Boolean algebra defined by x ≤ y just when . This ability to mix external implication ⊢ and internal implication → in the one logic is among the essential differences between sequent calculus and propositional calculus.
Applications
Boolean algebra as the calculus of two values is fundamental to computer circuits, computer programming, and mathematical logic, and is also used in other areas of mathematics such as set theory and statistics.
Computers
In the early 20th century, several electrical engineers intuitively recognized that Boolean algebra was analogous to the behavior of certain types of electrical circuits. Claude Shannon formally proved such behavior was logically equivalent to Boolean algebra in his 1937 master's thesis, A Symbolic Analysis of Relay and Switching Circuits.
Today, all modern general-purpose computers perform their functions using two-value Boolean logic; that is, their electrical circuits are a physical manifestation of two-value Boolean logic. They achieve this in various ways: as voltages on wires in high-speed circuits and capacitive storage devices, as orientations of a magnetic domain in ferromagnetic storage devices, as holes in punched cards or paper tape, and so on. (Some early computers used decimal circuits or mechanisms instead of two-valued logic circuits.)
Of course, it is possible to code more than two symbols in any given medium. For example, one might use respectively 0, 1, 2, and 3 volts to code a four-symbol alphabet on a wire, or holes of different sizes in a punched card. In practice, the tight constraints of high speed, small size, and low power combine to make noise a major factor. This makes it hard to distinguish between symbols when there are several possible symbols that could occur at a single site. Rather than attempting to distinguish between four voltages on one wire, digital designers have settled on two voltages per wire, high and low.
Computers use two-value Boolean circuits for the above reasons. The most common computer architectures use ordered sequences of Boolean values, called bits, of 32 or 64 values, e.g. 01101000110101100101010101001011. When programming in machine code, assembly language, and certain other programming languages, programmers work with the low-level digital structure of the data registers. These registers operate on voltages, where zero volts represents Boolean 0, and a reference voltage (often +5 V, +3.3 V, or +1.8 V) represents Boolean 1. Such languages support both numeric operations and logical operations. In this context, "numeric" means that the computer treats sequences of bits as binary numbers (base two numbers) and executes arithmetic operations like add, subtract, multiply, or divide. "Logical" refers to the Boolean logical operations of disjunction, conjunction, and negation between two sequences of bits, in which each bit in one sequence is simply compared to its counterpart in the other sequence. Programmers therefore have the option of working in and applying the rules of either numeric algebra or Boolean algebra as needed. A core differentiating feature between these families of operations is the existence of the carry operation in the first but not the second.
Two-valued logic
Other areas where two values is a good choice are the law and mathematics. In everyday relaxed conversation, nuanced or complex answers such as "maybe" or "only on the weekend" are acceptable. In more focused situations such as a court of law or theorem-based mathematics, however, it is deemed advantageous to frame questions so as to admit a simple yes-or-no answer—is the defendant guilty or not guilty, is the proposition true or false—and to disallow any other answer. However, limiting this might prove in practice for the respondent, the principle of the simple yes–no question has become a central feature of both judicial and mathematical logic, making two-valued logic deserving of organization and study in its own right.
A central concept of set theory is membership. An organization may permit multiple degrees of membership, such as novice, associate, and full. With sets, however, an element is either in or out. The candidates for membership in a set work just like the wires in a digital computer: each candidate is either a member or a nonmember, just as each wire is either high or low.
Algebra being a fundamental tool in any area amenable to mathematical treatment, these considerations combine to make the algebra of two values of fundamental importance to computer hardware, mathematical logic, and set theory.
Two-valued logic can be extended to multi-valued logic, notably by replacing the Boolean domain {0, 1} with the unit interval [0,1], in which case rather than only taking values 0 or 1, any value between and including 0 and 1 can be assumed. Algebraically, negation (NOT) is replaced with 1 − x, conjunction (AND) is replaced with multiplication (xy), and disjunction (OR) is defined via De Morgan's law. Interpreting these values as logical truth values yields a multi-valued logic, which forms the basis for fuzzy logic and probabilistic logic. In these interpretations, a value is interpreted as the "degree" of truth – to what extent a proposition is true, or the probability that the proposition is true.
Boolean operations
The original application for Boolean operations was mathematical logic, where it combines the truth values, true or false, of individual formulas.
Natural language
Natural languages such as English have words for several Boolean operations, in particular conjunction (and), disjunction (or), negation (not), and implication (implies). But not is synonymous with and not. When used to combine situational assertions such as "the block is on the table" and "cats drink milk", which naïvely are either true or false, the meanings of these logical connectives often have the meaning of their logical counterparts. However, with descriptions of behavior such as "Jim walked through the door", one starts to notice differences such as failure of commutativity, for example, the conjunction of "Jim opened the door" with "Jim walked through the door" in that order is not equivalent to their conjunction in the other order, since and usually means and then in such cases. Questions can be similar: the order "Is the sky blue, and why is the sky blue?" makes more sense than the reverse order. Conjunctive commands about behavior are like behavioral assertions, as in get dressed and go to school. Disjunctive commands such love me or leave me or fish or cut bait tend to be asymmetric via the implication that one alternative is less preferable. Conjoined nouns such as tea and milk generally describe aggregation as with set union while tea or milk is a choice. However, context can reverse these senses, as in your choices are coffee and tea which usually means the same as your choices are coffee or tea (alternatives). Double negation, as in "I don't not like milk", rarely means literally "I do like milk" but rather conveys some sort of hedging, as though to imply that there is a third possibility. "Not not P" can be loosely interpreted as "surely P", and although P necessarily implies "not not P," the converse is suspect in English, much as with intuitionistic logic. In view of the highly idiosyncratic usage of conjunctions in natural languages, Boolean algebra cannot be considered a reliable framework for interpreting them.
Digital logic
Boolean operations are used in digital logic to combine the bits carried on individual wires, thereby interpreting them over {0,1}. When a vector of n identical binary gates are used to combine two bit vectors each of n bits, the individual bit operations can be understood collectively as a single operation on values from a Boolean algebra with 2n elements.
Naive set theory
Naive set theory interprets Boolean operations as acting on subsets of a given set X. As we saw earlier this behavior exactly parallels the coordinate-wise combinations of bit vectors, with the union of two sets corresponding to the disjunction of two bit vectors and so on.
Video cards
The 256-element free Boolean algebra on three generators is deployed in computer displays based on raster graphics, which use bit blit to manipulate whole regions consisting of pixels, relying on Boolean operations to specify how the source region should be combined with the destination, typically with the help of a third region called the mask. Modern video cards offer all ternary operations for this purpose, with the choice of operation being a one-byte (8-bit) parameter. The constants or , or , and or allow Boolean operations such as (meaning XOR the source and destination and then AND the result with the mask) to be written directly as a constant denoting a byte calculated at compile time, in the example, if just , etc. At run time the video card interprets the byte as the raster operation indicated by the original expression in a uniform way that requires remarkably little hardware and which takes time completely independent of the complexity of the expression.
Modeling and CAD
Solid modeling systems for computer aided design offer a variety of methods for building objects from other objects, combination by Boolean operations being one of them. In this method the space in which objects exist is understood as a set S of voxels (the three-dimensional analogue of pixels in two-dimensional graphics) and shapes are defined as subsets of S, allowing objects to be combined as sets via union, intersection, etc. One obvious use is in building a complex shape from simple shapes simply as the union of the latter. Another use is in sculpting understood as removal of material: any grinding, milling, routing, or drilling operation that can be performed with physical machinery on physical materials can be simulated on the computer with the Boolean operation or , which in set theory is set difference, remove the elements of y from those of x. Thus given two shapes one to be machined and the other the material to be removed, the result of machining the former to remove the latter is described simply as their set difference.
Boolean searches
Search engine queries also employ Boolean logic. For this application, each web page on the Internet may be considered to be an "element" of a "set." The following examples use a syntax supported by Google.
Doublequotes are used to combine whitespace-separated words into a single search term.
Whitespace is used to specify logical AND, as it is the default operator for joining search terms:
"Search term 1" "Search term 2"
The OR keyword is used for logical OR:
"Search term 1" OR "Search term 2"
A prefixed minus sign is used for logical NOT:
"Search term 1" −"Search term 2"
See also
Boolean algebras canonically defined
Boolean differential calculus
Booleo
Cantor algebra
Heyting algebra
List of Boolean algebra topics
Logic design
Principia Mathematica Three-valued logic
Vector logic
Notes
References
Further reading
Bocheński, Józef Maria (1959). A Précis of Mathematical Logic''. Translated from the French and German editions by Otto Bird. Dordrecht, South Holland: D. Reidel.
Historical perspective
, several relevant chapters by Hailperin, Valencia, and Grattan-Guinness
External links
1847 introductions
Algebraic logic
Articles with example code | Boolean algebra | [
"Mathematics"
] | 11,081 | [
"Boolean algebra",
"Fields of abstract algebra",
"Mathematical logic",
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54,477,794 | https://en.wikipedia.org/wiki/Resistive%20plate%20chamber | A Resistive plate chamber (RPC) is a particle detector widely used in high energy physics. They are used for detecting muons in most of the modern experiments including ATLAS, CMS, and BES III.
References
Particle detectors
Science experiments | Resistive plate chamber | [
"Technology",
"Engineering"
] | 51 | [
"Particle detectors",
"Measuring instruments"
] |
54,477,872 | https://en.wikipedia.org/wiki/Young%27s%20inequality%20for%20products | In mathematics, Young's inequality for products is a mathematical inequality about the product of two numbers. The inequality is named after William Henry Young and should not be confused with Young's convolution inequality.
Young's inequality for products can be used to prove Hölder's inequality. It is also widely used to estimate the norm of nonlinear terms in PDE theory, since it allows one to estimate a product of two terms by a sum of the same terms raised to a power and scaled.
Standard version for conjugate Hölder exponents
The standard form of the inequality is the following, which can be used to prove Hölder's inequality.
A second proof is via Jensen's inequality.
Yet another proof is to first prove it with an then apply the resulting inequality to . The proof below illustrates also why Hölder conjugate exponent is the only possible parameter that makes Young's inequality hold for all non-negative values. The details follow:
Young's inequality may equivalently be written as
Where this is just the concavity of the logarithm function.
Equality holds if and only if or
This also follows from the weighted AM-GM inequality.
Generalizations
Elementary case
An elementary case of Young's inequality is the inequality with exponent
which also gives rise to the so-called Young's inequality with (valid for every ), sometimes called the Peter–Paul inequality.
This name refers to the fact that tighter control of the second term is achieved at the cost of losing some control of the first term – one must "rob Peter to pay Paul"
Proof: Young's inequality with exponent is the special case However, it has a more elementary proof.
Start by observing that the square of every real number is zero or positive. Therefore, for every pair of real numbers and we can write:
Work out the square of the right hand side:
Add to both sides:
Divide both sides by 2 and we have Young's inequality with exponent
Young's inequality with follows by substituting and as below into Young's inequality with exponent
Matricial generalization
T. Ando proved a generalization of Young's inequality for complex matrices ordered
by Loewner ordering. It states that for any pair of complex matrices of order there exists a unitary matrix such that
where denotes the conjugate transpose of the matrix and
Standard version for increasing functions
For the standard version of the inequality,
let denote a real-valued, continuous and strictly increasing function on with and Let denote the inverse function of Then, for all and
with equality if and only if
With and this reduces to standard version for conjugate Hölder exponents.
For details and generalizations we refer to the paper of Mitroi & Niculescu.
Generalization using Fenchel–Legendre transforms
By denoting the convex conjugate of a real function by we obtain
This follows immediately from the definition of the convex conjugate. For a convex function this also follows from the Legendre transformation.
More generally, if is defined on a real vector space and its convex conjugate is denoted by (and is defined on the dual space ), then
where is the dual pairing.
Examples
The convex conjugate of is with such that and thus Young's inequality for conjugate Hölder exponents mentioned above is a special case.
The Legendre transform of is , hence for all non-negative and This estimate is useful in large deviations theory under exponential moment conditions, because appears in the definition of relative entropy, which is the rate function in Sanov's theorem.
See also
Notes
References
External links
Young's Inequality at PlanetMath
Articles containing proofs
Inequalities | Young's inequality for products | [
"Mathematics"
] | 749 | [
"Binary relations",
"Mathematical relations",
"Inequalities (mathematics)",
"Mathematical problems",
"Articles containing proofs",
"Mathematical theorems"
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54,480,204 | https://en.wikipedia.org/wiki/Heinrich%20Adolph%20Baumhauer | Heinrich Adolph Baumhauer (26 October 1848, Bonn, Kingdom of Prussia - 1 August 1926, Freiburg, Switzerland) was a German chemist and mineralogist.
Baumhauer was the son of lithographer and merchant Mathias Baumhauer (1810–70) and Anna Margaretha Käuffer (variously Kaeuffer, Keuffer, Kaufmann) of Bonn. He studied in Bonn from 1866 to 1869 with Friedrich August Kekule von Stradonitz, Hans Heinrich Landolt and Gerhard vom Rath, receiving his doctorate for the dissertation “Die Reduction des Nitrobenzols durch Chlor-und Bromwasserstoff.” He spent an additional year studying at Göttingen in 1870.
In 1871 Baumhauer became a teacher at the Technical University in Frankenberg, Saxony. After a short period of teaching at the Handelsschule in Hildesheim in 1872, he became a chemistry teacher from 1873 to 1896 at the agricultural school of Lüdinghausen, Westphalia. From 1895 to 1925 he was professor of mineralogy and after 1906/1907 also a professor of inorganic chemistry in Freiburg, Switzerland. He was appointed Director of the newly created Department of Mineralogy at the University of Freiburg in 1896, and led the Freiburger Institut für Mineralogie until 1925.
In 1870 he wrote about the relationship between atomic weights and the properties of elements, and proposed his own periodic system on spirals based on increasing atomic weights. He also wrote textbooks on inorganic chemistry (1884), organic chemistry (1885), and mineralogy (1884). He was well-known for his book Das Reich der Kristalle ("The Kingdom of Crystals", 1889).
He evaluated etching figures on crystals and made studies on minerals from dolomite and new minerals. The etching method he developed contributed to the understanding of crystalline structures. His book Die Resultate der Aetzmethode ("The results of the Aetz method", 1894) was the standard resource on this method until 1927. He was the first to introduce the idea of polytypism in minerals.
Baumhauer was the first to describe the mineral Rathite which he named for Gerhard vom Rath. He also discovered Seligmannite, which was named in honor of Gustav Seligmann. A mineral is named in his honor as well: the rare dark gray lead-arsenic-sulphide Baumhauerite (Pb 3 As 4 S 9), which is found in the Lengenbach Quarry in Binntal, Switzerland. Baumhauer's collection of minerals from the Binntal, containing more than 750 pieces as well as handwritten observation journals, correspondence, and other materials, is held by the Freiburger Institut für Mineralogie. His collection helped to establish the reputation of the Institut.
Baumhauer became a member of the Mineralogical Society of St. Petersburg in 1878, an honorary member of the Mineralogical Society of Great Britain and Ireland in 1879, a member of the Mineralogical Society of London in 1905 and a member of the Leopoldina or German Academy of Natural Scientists in 1926.
References
1848 births
1926 deaths
Members of the German National Academy of Sciences Leopoldina
People involved with the periodic table | Heinrich Adolph Baumhauer | [
"Chemistry"
] | 669 | [
"Periodic table",
"People involved with the periodic table"
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54,480,612 | https://en.wikipedia.org/wiki/DMTMM | DMTMM (4-(4,6-dimethoxy-1,3,5-triazin-2-yl)-4-methyl-morpholinium chloride) is an organic triazine derivative commonly used for activation of carboxylic acids, particularly for amide synthesis. Amide coupling is one of the most common reactions in organic chemistry and DMTMM is one reagent used for that reaction. The mechanism of DMTMM coupling is similar to other common amide coupling reactions involving activated carboxylic acids. Its precursor, 2-chloro-4,6,-dimethoxy-1,3,5-triazine (CDMT), has also been used for amide coupling. DMTMM has also been used to synthesize other carboxylic functional groups such as esters and anhydrides. DMTMM is usually used in the chloride form but the tetrafluoroborate salt is also commercially available.
Synthesis
DMTMM is prepared by reaction of 2-chloro-4,6-dimethoxy-1,3,5-triazine (CDMT) with N-methylmorpholine (NMM). It was first reported in 1999. CDMT spontaneously reacts with NMM to form the quaternary ammonium chloride salt of DMTMM.
Reactions
Amides
Amides can be readily prepared from the corresponding carboxylic acid and amine using DMTMM coupling. DMTMM has been shown to be preferable to other coupling agents in several cases, such as for sterically hindered amines and for ligation of polysaccharides such as hyaluronic acid.
Other carboxylic derivatives
Despite primarily being used for amide synthesis, DMTMM can also be used to make esters from the corresponding alcohol and carboxylic acid. DMTMM has also been applied to anhydride synthesis. The synthesis of each carboxylic derivative is similar, relying on the activation of the starting carboxylic acid followed by nucleophilic attack by another molecule.
Coupling mechanism
DMTMM uses a typical mechanism to form carboxylic acid derivatives. First, the carboxylic acid reacts with DMTMM to form the active ester, releasing a molecule of N-methylmorpholinium (NMM). The resulting ester is highly reactive and can undergo a nucleophilic attack by an amine, an alcohol, or another nucleophile. A molecule of 4,6,-dimethoxy-1,3,5-triazin-2-ol is released and the corresponding carboxylic derivative is formed.
Safety
DMTMM can cause damage to the skin and eyes and may be toxic if ingested. Protective gloves, lab coats, and eye protection should be employed to reduce exposure while using DMTMM. DMTMM should be stored at -20 °C and kept dry.
References
Morpholines
Triazines
Peptide coupling reagents
Chlorides
Quaternary ammonium compounds | DMTMM | [
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54,480,633 | https://en.wikipedia.org/wiki/Institute%20for%20the%20History%20and%20Theory%20of%20Architecture | The Institute for the History and Theory of Architecture (; gta) is a teaching and research institute at the Department of Architecture of ETH Zurich, situated on the ETH Zurich’s Hönggerberg Campus site.
History
The Institute for the History and Theory of Architecture (gta) was founded on 1 January 1967 as a research body at the Architecture Department of ETH Zurich. The opening symposium was held on 23 June 1967.
Since its beginnings in 1967, the past and the present, theory and practice, have been the cornerstones and reference framework for the work undertaken at the Institute for the History and Theory of Architecture (gta). Besides teaching activities in the fields of the history of art and architecture, architectural theory and urban design, the institute’s core focus since its launch has lain in mediating and exploring architecture in its historical depth and thematic breadth.
The results of the institute’s in-house research, which is primarily influenced by the areas of interest of the teaching staff and the holdings of the simultaneously established archive, have been presented since 1968 in a publication series. These first appeared in cooperation with the Birkhäuser publishing house (in the “rainbow series”), later with the Ammann publishing house and since the mid-1980s in the gta Verlag, which today enjoys the reputation of being one of the leading architecture publishers.
The absorption of the so-called Semper Archive from the ETH Bibliothek on the occasion of the creation of the institute forms the foundation of the gta Archives, which over time has advanced to become an internationally renowned research facility.
Since then, the main acquisition emphasis has been on the architecture of the nineteenth century and the pre-modern, modern (Swiss) architecture in the form of collections (Congrès Internationaux d'Architecture Moderne (CIAM)), as well as advance legacies and bequests of individual architects of international stature (including Karl Moser, Hans Bernoulli, Lux Guyer, Haefeli Moser Steiger, Ernst Gisel, Fritz Haller and Trix and Robert Haussmann).
The organisational office for exhibitions by the ETH Zurich’s Department of Architecture became incorporated in the institute in 1974, and – since 1986 as gta Exhibitions – affords a wide public insight into contemporary architectural discourse and current research at the department.
Institute directors
Adolf Max Vogt (1920–2013), director from 1967 to 1974 and 1981 to 1982
Bernhard Hoesli (1923–1984), director from 1975 to 1980
Heinz Ronner (1924–1992), director from 1983 to 1987
Werner Oechslin (born 1944), director from 1987 to 1998 and 1999 to 2006
Kurt W. Forster (born 1935), director from 1998 to 1999
Andreas Tönnesmann (1953–2014), director from 2006 to 2010
Vittorio Magnago Lampugnani (born 1951), director from 2010 to 2016
Laurent Stalder (born 1970), director from 2016 to 2021
Tom Avermaete (born 1971), director from 2021 to 2024
Philip Ursprung (born 1963) director since 2024
Professorial chairs and divisions
Today the institute encompasses the following professorial chairs:
Chair of the History and Theory of Urban Design, Tom Avermaete
Chair of the History and Theory of Architecture, Maarten Delbeke
Chair of Theory of Architecture, Laurent Stalder
Chair of the History of Art and Architecture, Philip Ursprung
The following divisions assist the research projects and convey their findings:
gta Archives
gta Verlag
gta Exhibitions
gta Digital
The gta Institute assists in the promotion of academic newcomers with its own doctoral programme (since 2012). The institute’s educational provisions are supplemented by the programme Master of Studies in the History and Theory of Architecture, which mediates between practice and scholarship (since 1992).
There is a close academic exchange with the Werner Oechslin Library Foundation, associated with the ETH Zurich via a cooperation agreement.
Teaching and research areas
The institute's task is to empirically appraise and theoretically reflect upon architecture in its historical depth and ideological breadth. Along with the establishing and verification of facts, the gta Institute has always been at pains to review applied methods in terms of their validity as models and to make them beneficial to contemporary architecture. As an institute, the gta researches and teaches the history of knowledge of architecture, building forms and techniques, the function of architecture and its relations to society and politics, the evolution of design and architectural thinking from the beginnings to today, as well as the methodologies of architectural history work ranging from building analysis through to the digital humanities.
References
External links
Official website of the Institute for the History and Theory of Architecture
Digital Art History Image Database of the gta Institute, ETH Zurich
Architectural history
ETH Zurich | Institute for the History and Theory of Architecture | [
"Engineering"
] | 979 | [
"Architectural history",
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54,480,888 | https://en.wikipedia.org/wiki/Heinrich%20Friedrich%20Gretschel | Heinrich Friedrich Gretschel (21 October 1830, in Prietitz near Elstra, Germany – 2 February 1892, in Freiburg, Switzerland) was a German mathematician and scientist.
In 1847, Gretschel became a student at the Technischen Bildungsanstalt (now TU Dresden). On 28 April 1851 he was enrolled at Leipzig University, where he studied mathematics, natural sciences and ancient languages. In 1854, he passed the examination for the higher school office in the first ranking and became a teacher at the Leipziger Gesamtgymnasium.
On 2 January 1873 he was promoted by the Faculty of Philosophy of the University of Leipzig as a result of completing the mathematical dissertation, Lehrbuch zur Einführung in die organische Geometrie ("Introduction to organic geometry").
On 7 January 1873 he became professor of mathematics and geometric construction at the Bergakademie Freiberg, a position that he held until his death in 1892.
In 1876, Gretschel became a Bergrat professor. During 1875–1880, 1881–1883, and 1886–1889 he belonged to the Bergakademischen Senate.
Gretschel wrote and lectured in a wide range of fields, publishing books about meteorology, physics, chemistry, astronomy, geometry and cartography. He and Georg Bornemann wrote about the organization of the periodic table, published as Das Naturliche System der Elemente (1883).
Gretschel also wrote about the construction of stringed instruments in the violin family and co-wrote a book on the construction of the pianoforte with Julius Blüthner, Lehrbuch des Pianofortebaues (1872).
References
1830 births
1892 deaths
Scientists from Saxony
19th-century German mathematicians
People involved with the periodic table
People from Bautzen (district)
People from the Kingdom of Saxony
Mathematicians from the German Empire
Leipzig University alumni | Heinrich Friedrich Gretschel | [
"Chemistry"
] | 385 | [
"Periodic table",
"People involved with the periodic table"
] |
54,483,638 | https://en.wikipedia.org/wiki/Gilbreth%20Medal | The Gilbreth Medal is named after Frank Bunker Gilbreth Sr. and Lillian Gilbreth and is presented in recognition of excellence in the field of motion, skill, and fatigue study. Originally awarded in 1931 by the Society of Industrial Engineers, the award continues to be presented following the organization's merger in 1936 with The Taylor Society under the new organization, The Society for Advancement of Management.
Award winners
The award winners are:
1931 Dr. Lilian Gilbreth, Ph.D.
1933 President Herbert Hoover
1936 Ordway Tead
1937 Allan H. Mogensen
1938 Erwin Schell
1939 Joseph Wickham Roe
1940 David B. Porter
1941 Ralph Mosser Barnes
1942 Glenn L. Gardiner
1943 Elmer William Engstrom
1944 John A. Aldridge
1945 James Secor Perkins
1946 Harold Bright Maynard
1947 Don F. Copell
1948 Anne G. Shaw
1949 James Keith Louden
1950 Phil Carroll
1951 Ralph Presgrave
1952 William R. Mullee
1953 Marvin Everett Mundel
1954 Craig Lee Taylor
1955 Gustave J. Stegemerten
1956 Herbert F. Goodwin
1957 Harold G. Dunlap
1958 John L. Schwab (1892–1970)
1959 Gerald B. Bailey
1960 Leo M. Moore
1961 Gerald Nadler
1962 Richard Muther
1963 Lee Whitson
1964 Oliver. J. Sizelove
1965 Robert T. Livingston
1966 Daniel M. Braum
1968 Lucien A. Brouha
1969 Erwin Rudolph Tichauer
1971 Joseph H. Quick
1972 Henry Viscardi, Jr.
1973 Richard M. Paget
1977 Arthur Spinanger
1981 Joseph M. Juran
1982 Mavin Mundel
1989 Wallace James Richardson
1991 Alan Pritsker
1996 Ernestine Gilbreth Carey
2001 David S. Ferguson
2002 Mary Ann Hainthaler
2004 Akira Takanka
References
Awards established in 1931
Management awards | Gilbreth Medal | [
"Technology"
] | 367 | [
"Science and technology awards",
"Management awards"
] |
54,483,847 | https://en.wikipedia.org/wiki/Chevalley%20restriction%20theorem | In the mathematical theory of Lie groups, the Chevalley restriction theorem describes functions on a Lie algebra which are invariant under the action of a Lie group in terms of functions on a Cartan subalgebra.
Statement
Chevalley's theorem requires the following notation:
Chevalley's theorem asserts that the restriction of polynomial functions induces an isomorphism
.
Proofs
gives a proof using properties of representations of highest weight. give a proof of Chevalley's theorem exploiting the geometric properties of the map .
References
Lie groups
Lie algebras
Representation theory
Algebraic geometry | Chevalley restriction theorem | [
"Mathematics"
] | 118 | [
"Lie groups",
"Mathematical structures",
"Fields of abstract algebra",
"Algebraic structures",
"Algebraic geometry"
] |
54,484,359 | https://en.wikipedia.org/wiki/International%20Academy%20for%20Production%20Engineering | The International Academy for Production Engineering (CIRP) is a professional body for research into production engineering. CIRP comes from the French acronym of College International pour la Recherche en Productique (CIRP).
CIRP was founded in 1951 as the International Institution for Production Engineering Research.
CIRP uses different platforms for scientific exchange. One of this is "CIRP Global Web Conference on Production Engineering Research" born in 2011.
The CSI of Naples University, Ing Fabrizio Pietrafesa provided technical support for multimedial contents
in 2014.
References
Further reading
Remmerswaal, Joost L. (Ed.) (1991) Forty years of CIRP : the history of the International Institution for Production Engineering Research, 1951-1991. International Academy for Production Engineering.
External links
https://www.cirp.net/
Organizations based in Paris
1951 establishments in France
Engineering organizations
Learned societies of France | International Academy for Production Engineering | [
"Engineering"
] | 186 | [
"nan"
] |
54,484,502 | https://en.wikipedia.org/wiki/Thomas%E2%80%93Fermi%20equation | In mathematics, the Thomas–Fermi equation for the neutral atom is a second order non-linear ordinary differential equation, named after Llewellyn Thomas and Enrico Fermi, which can be derived by applying the Thomas–Fermi model to atoms. The equation reads
subject to the boundary conditions
If approaches zero as becomes large, this equation models the charge distribution of a neutral atom as a function of radius . Solutions where becomes zero at finite model positive ions. For solutions where becomes large and positive as becomes large, it can be interpreted as a model of a compressed atom, where the charge is squeezed into a smaller space. In this case the atom ends at the value of for which .
Transformations
Introducing the transformation converts the equation to
This equation is similar to Lane–Emden equation with polytropic index except the sign difference.
The original equation is invariant under the transformation . Hence, the equation can be made equidimensional by introducing into the equation, leading to
so that the substitution reduces the equation to
Treating as the dependent variable and as the independent variable, we can reduce the above equation to
But this first order equation has no known explicit solution, hence, the approach turns to either numerical or approximate methods.
Sommerfeld's approximation
The equation has a particular solution , which satisfies the boundary condition that as , but not the boundary condition y(0)=1. This particular solution is
Arnold Sommerfeld used this particular solution and provided an approximate solution which can satisfy the other boundary condition in 1932. If the transformation is introduced, the equation becomes
The particular solution in the transformed variable is then . So one assumes a solution of the form and if this is substituted in the above equation and the coefficients of are equated, one obtains the value for , which is given by the roots of the equation . The two roots are , where we need to take the positive root to avoid the singularity at the origin. This solution already satisfies the first boundary condition (), so, to satisfy the second boundary condition, one writes to the same level of accuracy for an arbitrary
The second boundary condition will be satisfied if as . This condition is satisfied if and since , Sommerfeld found the approximation as . Therefore, the approximate solution is
This solution predicts the correct solution accurately for large , but still fails near the origin.
Solution near origin
Enrico Fermi provided the solution for and later extended by Edward B. Baker. Hence for ,
where .
It has been reported by Salvatore Esposito that the Italian physicist Ettore Majorana found in 1928 a semi-analytical series solution to the Thomas–Fermi equation for the neutral atom, which however remained unpublished until 2001. Using this approach it is possible to compute the constant B mentioned above to practically arbitrarily high accuracy; for example, its value to 100 digits is .
References
Eponymous equations of physics
Ordinary differential equations | Thomas–Fermi equation | [
"Physics"
] | 585 | [
"Eponymous equations of physics",
"Equations of physics"
] |
54,484,653 | https://en.wikipedia.org/wiki/Wallace%20Clark%20Award | The Wallace Clark Award or Wallace Clark Medal is a former management award for Distinguished Contribution to Scientific Management, named after Henry Wallace Clark (1880-1948). The Wallace Clark Award was established in 1949 and was sponsored by the American Management Association (AMA), the American Society of Mechanical Engineers (ASME), the Association for Consulting Management Engineers and the Society for the Advancement of Management.
The first Wallace Clark Medal was in 1948 awarded in the Swiss Hugo de Haan, who was in those days executive secretary of Comite International de l'Organisation Scientifique (CIOS). This organization was dedicated to the promotion of scientific management worldwide, and was founded in the first International Management Congress at Prague in 1924.
Award winners
1949. Hugo de Haan
1950. Theodore Limperg
1951. Lillian Gilbreth
1953. Erwin H. Schell
1954. Harold Bright Maynard
1955. Lyndall Urwick
1957. Walter Scott
1958. Harold F. Smiddy
1960. Berend Willem Berenschot
1963. Peter Drucker
1965. Phil Carroll
1966. K. S. Basu
1967. Joseph M. Juran
1968. Gerrit van der Wal
1969. Dwayne Orton
References
Awards established in 1949
Management awards | Wallace Clark Award | [
"Technology"
] | 254 | [
"Science and technology awards",
"Management awards",
"Science award stubs"
] |
54,484,655 | https://en.wikipedia.org/wiki/List%20of%20nonlinear%20ordinary%20differential%20equations | Differential equations are prominent in many scientific areas. Nonlinear ones are of particular interest for their commonality in describing real-world systems and how much more difficult they are to solve compared to linear differential equations. This list presents nonlinear ordinary differential equations that have been named, sorted by area of interest.
Mathematics
{|class="wikitable" style="background: white; color: black; text-align: left"
|-style="background: #eee"
!Name
!Order
!Equation
!Application
!Reference
|-
|Abel's differential equation of the first kind
|1
|
|Class of differential equation which may be solved implicitly
|
|-
|Abel's differential equation of the second kind
|1
|
|Class of differential equation which may be solved implicitly
|
|-
|Bernoulli equation
|1
|
|Class of differential equation which may be solved exactly
|
|-
|Binomial differential equation
|
|
|Class of differential equation which may sometimes be solved exactly
|
|-
|Briot-Bouquet Equation
|1
|
|Class of differential equation which may sometimes be solved exactly
|
|-
|Cherwell-Wright differential equation
|1
| or the related form
|An example of a nonlinear delay differential equation; applications in number theory, distribution of primes, and control theory
|
|-
|Chrystal's equation
|1
|
|Generalization of Clairaut's equation with a singular solution
|
|-
|Clairaut's equation
|1
|
|Particular case of d'Alembert's equation which may be solved exactly
|
|-
|d'Alembert's equation or Lagrange's equation
|1
|
|May be solved exactly
|
|-
|Darboux equation
|1
|
|Can be reduced to a Bernoulli differential equation; a general case of the Jacobi equation
|
|-
|Elliptic function
|1
|
|Equation for which the elliptic functions are solutions
|
|-
|Euler's differential equation
|1
|
|A separable differential equation
|
|-
|Euler's differential equation
|1
|
|A differential equation which may be solved with Bessel functions
|
|-
|Jacobi equation
|1
|
|Special case of the Darboux equation, integrable in closed form
|
|-
|Loewner differential equation
|1
|
|Important in complex analysis and geometric function theory
|
|-
|Logistic differential equation (sometimes known as the Verhulst model)
|2
|
|Special case of the Bernoulli differential equation; many applications including in population dynamics
|
|-
|Lorenz attractor
|1
|
|Chaos theory, dynamical systems, meteorology
|
|-
|Nahm equations
|1
|
|Differential geometry, gauge theory, mathematical physics, magnetic monopoles
|
|-
|Painlevé I transcendent
|2
|
|One of fifty classes of differential equation of the form ; the six Painlevé transcendents required new special functions to solve
|
|-
|Painlevé II transcendent
|2
|
|One of fifty classes of differential equation of the form ; the six Painlevé transcendents required new special functions to solve
|
|-
|Painlevé III transcendent
|2
|
|One of fifty classes of differential equation of the form ; the six Painlevé transcendents required new special functions to solve
|
|-
|Painlevé IV transcendent
|2
|
|One of fifty classes of differential equation of the form ; the six Painlevé transcendents required new special functions to solve
|
|-
|Painlevé V transcendent
|2
|
|One of fifty classes of differential equation of the form ; the six Painlevé transcendents required new special functions to solve
|
|-
|Painlevé VI transcendent
|2
|
|All of the other Painlevé transcendents are degenerations of the sixth
|
|-
|Rabinovich–Fabrikant equations
|1
|
|Chaos theory, dynamical systems
|
|-
|Riccati equation
|1
|
|Class of first order differential equations that is quadratic in the unknown. Can reduce to Bernoulli differential equation or linear differential equation in certain cases
|
|-
|Rössler attractor
|1
|
|Chaos theory, dynamical systems
|
|}
Physics
{|class="wikitable" style="background: white; color: black; text-align: left"
|-style="background: #eee"
!Name
!Order
!Equation
!Applications
!Reference
|-
|Bellman's equation or Emden-Fowler's equation
|2
| (Emden-Fowler) which reduces to if (Bellman)
|Diffusion in a slab
|
|-
|Besant-Rayleigh-Plesset equation
|2
|
|Spherical bubble in fluid dynamics
|
|-
|Blasius equation
|3
|
|Blasius boundary layer
|
|-
|Chandrasekhar's white dwarf equation
|2
|
|Gravitational potential of white dwarf in astrophysics
|
|-
|De Boer-Ludford equation
|2
|
|Plasma physics
|
|-
|Emden–Chandrasekhar equation
|2
|
|Astrophysics
|
|-
|Ermakov-Pinney equation
|2
|
|Electromagnetism, oscillation, scalar field cosmologies
|
|-
|Falkner–Skan equation
|3
|
|Falkner–Skan boundary layer
|
|-
|Friedmann equations
|2
| and
|Physical cosmology
|
|-
|Heisenberg equation of motion
|1
|
|Quantum mechanics
|
|-
|Ivey's equation
|2
|
|Space charge theory
|
|-
|Kidder equation
|2
|
|Flow through porous medium
|
|-
|Krogdahl equation
|2
|
|Stellar pulsation in astrophysics
|
|-
|Lagerstrom equation
|2
|
|One dimensional viscous flow at low Reynolds numbers
|
|-
|Lane–Emden equation or polytropic differential equation
|2
|
|Astrophysics
|
|-
|Liñán's equation
|2
|
|Combustion
|
|-
|Pendulum equation
|2
|
|Mechanics
|
|-
|Poisson–Boltzmann equation (1d case)
|2
|
|Inflammability and the theory of thermal explosions
|
|-
|Stuart–Landau equation
|1
|
|Hydrodynamic stability
|
|-
|Taylor–Maccoll equation
|2
| where
|Flow behind a conical shock wave
|
|-
|Thomas–Fermi equation
|2
|
|Quantum mechanics
|
|-
|Toda lattice
|1
|where
|Model of one-dimensional crystal in solid-state physics, Langmuir oscillations in plasma, quantum cohomology; notable for being a completely integrable system
|
|}
Engineering
{|class="wikitable" style="background: white; color: black; text-align: left"
|-style="background: #eee"
!Name
!Order
!Equation
!Applications
!Reference
|-
|Duffing equation
|2
|
|Oscillators, hysteresis, chaotic dynamical systems
|
|-
|Lewis regulator
|2
|
|Oscillators
|
|-
|Liénard equation
|2
| with odd and even
|Oscillators, electrical engineering, dynamical systems
|
|-
|Rayleigh equation
|2
|
|Oscillators (especially auto-oscillation), acoustics; the Van der Pol equation is a Rayleigh equation
|
|-
|Van der Pol equation
|2
|
|Oscillators, electrical engineering, chaotic dynamical systems
|
|}
Chemistry
Biology and medicine
Economics and finance
See also
List of linear ordinary differential equations
List of nonlinear partial differential equations
List of named differential equations
List of stochastic differential equations
References
differential, ordinary, nonlinear
Nonlinear systems | List of nonlinear ordinary differential equations | [
"Mathematics"
] | 1,633 | [
"Mathematical objects",
"Equations",
"Nonlinear systems",
"Mathematical tables",
"Lists of equations",
"Dynamical systems"
] |
54,484,721 | https://en.wikipedia.org/wiki/US%20Fleet%20Tracking | US Fleet Tracking is a privately owned company that specializes in manufacturing and distributing GPS Tracking products and accessories designed to enable businesses and individuals to monitor their mobile assets and vehicle fleets, tracking those vehicles live, in realtime, as they move.
Business
The company manufactures a variety of GPS (Global Positioning System) trackers intended for use in vehicles and other mobile assets. It also offers an Internet-based subscription service that gives clients access to 5- or 10-second updates around the clock from each installed GPS tracker. The system collects and stores data from each unit on a 24/7 basis, and can generate reports showing the activity of each vehicle during a specified time frame. The system can be configured to transmit alerts to the account owner if certain user-defined conditions are detected, such as a monitored vehicle exceeding acceptable speeds or entering/exiting a specific area.
History
During his employment as IT Director at Metropolitan EMS (MEMS) in Little Rock, Arkansas (1997-1998), Jerry Hunter began working with 911 Emergency Dispatch systems and tablet-based data acquisition systems. His subsequent contract with Little Rock Police Department resulted in his development of 911 Emergency Dispatch system there, as well as in-car mobile data terminals with live GPS tracking, live camera system, messaging, and NCIC gateway and client products. These systems communicated primarily through proprietary dataradio systems from Motorola and Kenwood. Hunter founded predecessor company Pinnacle Labs Corp. in Arkansas in 2001, marketing his dispatch and in-car police systems throughout the US. This experience was critical in creating the foundation on which US Fleet Tracking's live tracking technology was built.
With the advent of Google Maps and the proliferation of wireless data services from Sprint and AT&T, Hunter founded US Fleet Tracking in 2005. Google Maps provided the ability to convert the dispatch platform into a web-based application without the need for specialized local maps and aerial imagery, and the proliferation of wireless data services eliminated the need for expensive private data radio towers. Relocating to Oklahoma City in 2006, Hunter brought this GPS tracking technology to the general marketplace, with the aim of providing affordable LIVE GPS tracking technology to mobile workforce businesses as well as private individuals.
In 2007, US Fleet Tracking provided live GPS tracking to Gameday Management Group for use at the Super Bowl, tracking AFC and NFC Team buses, media buses, press buses, halftime entertainers, team owners and team family limousines, and other critical assets. US Fleet Tracking continues to provide these services for the Super Bowl each year, as it has each year since 2007 (through 2020). In 2013, US Fleet Tracking sponsored the FLS Microjet for its appearance at the EAA AirVenture Oshkosh airshow in Oshkosh, Wisconsin. The company demonstrated its live tracking technology at the event by installing its proprietary GPS equipment on the FLS Microjet and allowing the public to follow the course of the aircraft via a website in real time during the exhibition.
Partnerships
In 2013 US Fleet Tracking announced the formation of a strategic partnership with AgTrax Technologies, developers of accounting software programs for agri-businesses. The partnership resulted in the integration of AgTrax’s software with US Fleet Tracking’s TotalView system to create an enhanced GPS tracking system that enables real-time monitoring of mobile agricultural equipment.
In 2016 US Fleet Tracking established a partnership with Gorilla Safety, a Houston-based company specializing in software for the transportation sector, to create a fully integrated system that combines live GPS tracking with electronic logging features compliant with the Electronic Logging Device (ELD) mandate of the Federal Motor Carrier Safety Administration (FMCSA).
Clients
US Fleet Tracking’s live GPS services have been used by organizers and logistics managers for countless high-profile events, including every Super Bowl (XLI through LIV) since 2007, the 2010 Winter Olympics, the 2010 Pro Bowl, the 2011 NHL All-Star Game, the 2012 Summer Olympics, the 2012 Republican National Convention, and the 2011 & 2012 Hoka Hey Motorcycle Challenge.
Awards and recognition
US Fleet Tracking has received the following honors:
• Silver, 2007 M2M Value Chain Awards, Enabler – M2M Magazine
• Bronze, 2008 M2M Value Chain Awards, Enabler – M2M Magazine
• 2010 Innovator of the Year – The Journal Record
• 2012 Rock Solid Award, Mobile Office – ProPickup
References
2005 establishments in the United States
Global Positioning System
Software companies of the United States
Navigational equipment manufacturers | US Fleet Tracking | [
"Technology",
"Engineering"
] | 893 | [
"Global Positioning System",
"Wireless locating",
"Aircraft instruments",
"Aerospace engineering"
] |
54,484,831 | https://en.wikipedia.org/wiki/NGC%207603 | NGC 7603 is a spiral Seyfert galaxy in the constellation Pisces. It is listed (as Arp 92) in the Atlas of Peculiar Galaxies. It is interacting with the smaller elliptical galaxy PGC 71041 nearby.
This galaxy pair has long been a cornerstone for those who are critical of the view that the universe is expanding, and advocates for non-standard cosmology such as Halton Arp, Fred Hoyle, and others. This is due to the position of two quasars, one at each edge of the filament connecting the two galaxies, with much more redshift than either galaxy.
References
External links
SEDS – NGC 7603
Simbad – NGC 7603
VizieR – NGC 7603
Pisces (constellation)
Unbarred spiral galaxies
Seyfert galaxies
7603
092
Interacting galaxies
Markarian galaxies | NGC 7603 | [
"Astronomy"
] | 177 | [
"Pisces (constellation)",
"Constellations"
] |
54,484,967 | https://en.wikipedia.org/wiki/NGC%201403 | NGC 1403 is a lenticular or elliptical galaxy in the constellation Eridanus. It was discovered in 1886 by Francis Preserved Leavenworth. It was thought to be a "very faint, extremely small, nebulous star" by John Louis Emil Dreyer, the compiler of the New General Catalogue.
See also
Spiral galaxy
List of NGC objects (1–1000)
Eridanus (constellation)
References
External links
SEDS
Lenticular galaxies
Eridanus (constellation)
1403
013445
Discoveries by Francis Leavenworth | NGC 1403 | [
"Astronomy"
] | 108 | [
"Eridanus (constellation)",
"Constellations"
] |
54,485,006 | https://en.wikipedia.org/wiki/Formal%20criteria%20for%20adjoint%20functors | In category theory, a branch of mathematics, the formal criteria for adjoint functors are criteria for the existence of a left or right adjoint of a given functor.
One criterion is the following, which first appeared in Peter J. Freyd's 1964 book Abelian Categories, an Introduction to the Theory of Functors:
Another criterion is:
See also
Anafunctor
References
Bibliography
Further reading
External link
Adjoint functors | Formal criteria for adjoint functors | [
"Mathematics"
] | 92 | [
"Mathematical structures",
"Category theory",
"Category theory stubs"
] |
53,174,400 | https://en.wikipedia.org/wiki/Kenneth%20Sims%20%28geologist%29 | Kenneth W. W. Sims (born 1959) is an American professor of isotope geology in the Department of Geology and Geophysics at the University of Wyoming. Sims operates the University of Wyoming High Precision Isotope Laboratory.
Professor Sims is married, has two children and lives in Laramie, Wyoming.
Research overview
Sims is a National Geographic explorer well known for using his technical mountaineering skills to collect geological samples from remote locations across the globe, including sampling molten magma from lava lakes deep within volcanic craters, collecting temporal sequences of lavas from high, technical ridges on the flanks of the world's tallest volcanoes, and using submersibles to obtain mid-ocean ridge basalts from the bottom of the Earth's oceans. Many of these adventures have been featured in National Geographic publications and documentaries, as well as numerous other media venues.
Sims’ research endeavors focus on obtaining hard-to-collect samples and then measuring unique and analytically challenging isotope systems to provide otherwise unobtainable answers to societally relevant questions about Earth systems science. Sims’ research applies a variety of isotopic techniques (U– and Th– decay series, cosmogenic nuclides, radiogenic isotopes, and non-traditional stable isotopes) to address a wide range of topics in earth and ocean sciences. Sims has published nearly one hundred research articles in peer-reviewed scientific journals, including Nature and Science. These publications cover a wide range of topics: magma genesis, differentiation, and degassing; continental and oceanic crustal construction; planetary accretion and core formation; trace-element partitioning; surficial weathering; paleo-oceanography; chemical oceanography; ground water hydrology; water-rock interaction; fumarolic activity; volcanic aerosol formation and dispersal; serpentinization; natural rates of carbon sequestration; and, shallow subsurface geophysics. Sims’ major contributions are determining the time scales and dynamics of magma genesis and volcanic processes.
Sims’ research is funded by the US National Science Foundation, National Geographic Society, the US Department of Energy, Woods Hole Oceanographic Institution and the University of Wyoming.
Career
Sims received a B.A. in geology in 1986 from Colorado College, graduating lllCum lllLaude with llHonors. He completed an M.Sc. at the University of New Mexico’s Institute of Meteoritics in 1989, where his research focused on chemical fractionation during the formation of the Earth’s core and continental crust. His Ph.D. was earned in 1995 from the University of California, Berkeley where his research focused on magma genesis in the Earth’s mantle. Sims worked as a student and then as a guest scientist for the Isotope and Nuclear Chemistry Group at the Los Alamos National Laboratory, New Mexico. After completing his Ph.D., Sims was awarded the Woods Hole Oceanographic Institution (WHOI) Postdoctoral Scholar Fellow from 1995-1997. He was then hired onto the WHOI scientific staff in 1997 where he remained as a tenured research scientist until 2009. In 2009 Sims moved to the department of geology and geophysics of the University of Wyoming, where he is now a full professor. Sims was a Visiting CNRS Fellow at the Institut Universitaire Européen de la Mer (IUEM), France in 2002. In 2016, Sims became a US Fulbright scholar and a visiting professor at the Instituto de Geofisico, Escuela Politécnica Nacional, Quito Ecuador. In his current role at the University of Wyoming, Sims is involved in a variety of research projects, graduate and undergraduate teaching, and the supervision of graduate students. Sims is the University of Wyoming Organizational Lead for the Yellowstone Volcano Observatory. Sims has received various academic accolades for his research and public engagement.
Additionally, Sims worked as a professional climbing instructor and high-altitude mountaineering guide for 23 years (1975-1998) including in Antarctica, Alaska, Mexico and Peru. During this period, he pioneered many difficult first ascents around the world.
Field work
Sims’ field work, primarily funded by the National Geographic Society and the National Science Foundation (NSF), has crossed the globe from the bottom of the Earth's oceans to the top of its highest volcanoes. Highlights of Sims’ field research include:
Antarctica
Sims has been to Antarctica fourteen times since 1989. He has worked both as a guide for science parties funded by the NSF and NASA (including as a guide and rigger for the NASA Dante Rover project), and also as a principal investigator funded by the NSF to conduct research on the volcanoes of Ross Island and Mt Morning. In particular, Sims has worked and published extensively on Mt Erebus, the world's southernmost active volcano, including descending into its active crater numerous times to collect recently erupted lava bombs from its persistent lava lake. Sims’ most recent expeditions (2012–2017) have been to study the volcanoes Mt Bird, Mt Terror and Hut Point on Ross Island and also the volcanic cones on Mt Discovery.
Democratic Republic of the Congo
Sims’ expeditions to the Democratic Republic of the Congo were funded by the National Geographic Society to film two documentaries and by NSF for research related to volcano hazard assessment. In his research pursuits, Sims has trekked deep into the Virunga jungles to access the remote, and often active volcano Nyamulagira, and he repeatedly descended into the active Nyamulagira crater to collect old lava flows from the crater walls and molten magma from the active lava lake.
Ecuador
Sims has conducted numerous expeditions into the Ecuadorian volcanoes. Funded by the National Geographic Society in 2014, Sims led a month-long expedition into the remote Sangay volcano (5,300 meters/17,400 feet ASL), which is one of the highest and most continuously active volcanoes in the world. In 2016, while living in Ecuador for six months on a US Fulbright Scholarship, Sims conducted several two-week expeditions to collect samples on the steep, glacially dissected flanks and high-altitude ridges of Chimborazo (6,263 meters/20,548 feet ASL). Sims has also conducted and published NSF- and UW-funded research on the volcanoes Reventador, Sumaco, and the Chalupas Caldera.
Mid-ocean ridges
Sims has researched the petrology of mid-ocean ridges extensively. Sims worked on several research expeditions to 9-10°N East Pacific Rise aboard the WHOI operated Research Vessel (RV) Atlantis utilizing the U.S. Navy-owned Deep Submergence Vehicle (DSV) Alvin and other remotely operated (DSL-120 and Jason) and autonomous (ABE) vehicles to conduct his research. Sims has also sent his graduate students on research expeditions to the Kolbeinsey Ridge, the SW Indian Ridge, 45°N Mid Atlantic Ridge, and 9°03 East Pacific Rise.
Yellowstone
Wyoming is home to one of the world's super-volcanos, Yellowstone, which also happens to host the world's most profound, and visually stunning example of an active continental hydrothermal system. Since moving to Wyoming, Sims has been coordinating the introduction of novel geochemical and geophysical techniques to study Yellowstone's “geohydrobiology”, which is the study of how Earth, water and life connect.
Other locations
Sims’ research has also taken him to volcanoes in Italy (Mt. Etna and Stromboli), Nicaragua (Vulcan Masaya), Iceland (Hekla, Theistareykir, Krafla), Hawaii (Kilauea, Mauna Loa, Hualalai, Mauna Kea and Haleakala), and New Mexico (Jemez Volcanic Field, Zuni-Bandera, and Raton-Clayton Volcanic Field). Sims has worked on problems related to serpentinization and carbonization in Samail Ophiolite of Oman, and the Josephine Peridotite in Oregon.
Public engagement
Sims’ research and scientific expeditions have been featured in: National Geographic Magazine (October 2004; April 2011); GEO Magazine (October 2012; 2017); National Geographic Explorer Kids (October 2011); Oceanus (Fall, 2006); Popular Mechanics (October 2006); New Scientist (July 2008; December 2008); CNN ("Great Big Story"); MentalFloss (August 2013); the children's book Lava Scientists: Careers on the Edge of Volcanoes (Sarah Latta, Enslow Publishing, Inc.); National Geographic Television (Man versus Volcano, April 2011; One Strange Rock, March 2018); National Geographic Weekend Radio (January 2015); Discovery Channel (Against the Elements, Spring 2009; Volcano Time Bomb, December 2012); NHK Japanese Public Television (Miracle Continent Antarctica); and, Boston Museum of Science (“Volcanoes on the Verge”). Sims contributes regularly to the National Geographic Explorers blog.
Special Awards and Honors
Source:
Fulbright US Scholar Award (2016–2017)
Top 10 Teacher Award, University of Wyoming (2015)
Extraordinary Merit in Research Award, University of Wyoming (2015)
National Geographic Society Explorer
Faculty Senate Speaker Award, University of Wyoming (2104)
Meritorious Teaching Award, University of Wyoming (2014)
Papadopoulos Fellow, Kincaid School, Houston, Texas (2012)
Mellon Independent Study Awards, Woods Hole Oceanographic Institution (1999; 2001; 2006; 2008)
Outstanding Graduate Student Instructor, University of California, Berkeley (1992)
Estwing Outstanding Senior Geologist, Colorado College (1986)
Getty Oil Fellowship, Colorado College (1984)
Significant publications
*Authors marked with an asterisk are graduate students working with Sims.
Mantle dynamics and magma genesis
Sims, K.W.W., S.J. Goldstein, J. Blichert-Toft, M.R. Perfit, P. Kelemen, D.J. Fornari, P. Michael, M.T. Murrell, S.R. Hart, D.J. DePaolo, G.D. Layne, and M. Jull (2002). “Chemical and isotopic constraints on the generation and transport of melt beneath the East Pacific Rise.” Geochimica et Cosmochimica Acta, 66, 19, 3481-3504. doi:10.1016/S0016-7037(02)00909-2.
Sims, K.W.W., M.T. Murrell, D.J. DePaolo, W.S. Baldridge, S.J. Goldstein, D. Clague and M. Jull (1999). “Porosity of the melting zone and variations in the solid mantle upwelling rate beneath Hawaii: Inferences from 238U–230Th–226Ra and 235U-231Pa disequilibria.” Geochimimica et Cosmochimica Acta, 63, 23, 4119-4138, doi: 10.1016/S0016-7037(99)00313-0.
Sims, K.W.W. and D.J. DePaolo (1997). “Inferences about mantle magma sources from incompatible element concentration ratios in oceanic basalts.” Geochimica et Cosmochimica Acta, 61, 4, 765-784. doi: 10.1016/S0016-7037(96)00372-9.
Sims, K.W.W., D.J. DePaolo, M.T. Murrrell, W.S. Baldridge, S.J. Goldstein, and D. Clague (1995). “Mechanisms of magma generation beneath Hawaii and Mid–Ocean ridges: U–Th and Sm–Nd isotopic evidence.” Science, 267, 508–512. doi: 10.1126/science.267.5197.508.
Sims, K.W.W., J. Blichert-Toft, P.R. Kyle, S. Pichat, J. Bluzstajn, P.J. Kelly, L.A. Ball, and G. D. Layne (2008). “A Sr, Nd, Hf, and Pb isotope perspective on the genesis and long-term evolution of alkaline magmas from Erebus volcano, Antarctica.” Invited article to special volume on Mt. Erebus in Journal of Volcanology and Geothermal Research, 177, 606-618. doi: 10.1016/j.jvolgeores.2007.08.006.
Sims, K.W.W., J. Maclennan, J. Blichert-Toft, E.M. Mervine, J. Bluzstajn, and K. Grönvold (2013). “Short length scale mantle heterogeneity beneath Iceland probed by glacial modulation of melting.” Earth and Planetary Science Letters, 379, 146-157, doi.org/10.1016/j.epsl.2013.07.027.
*Waters, C.L., K.W.W. Sims, M.R. Perfit, J. Blichert-Toft, and J. Blusztajn (2011). “Perspective on the genesis of E-MORB from Chemical and Isotopoic Heterogeneity at 9-10ºN East Pacific Rise.” Journal of Petrology, 52, 3, 565-602. doi:10.1093/petrology/egq091.
*Elkins, L.J., K.W.W. Sims, J. Prytulak, T. Elliott, N. Mattielli, J. Blichert-Toft, J. Blusztajn, C. Devey, D. Mertz, J.-G. Schilling, and M. Murrell (2011). “Understanding melt generation beneath the slow-spreading Kolbeinsey Ridge using 238U, 230Th, and 231Pa excesses.” Geochimica et Cosmochimica Acta, 75, 21, 6300-6329. doi:10.1016/j.gca.2011.08.020.
Oceanic crustal construction
Sims, K.W.W., J. Blichert-Toft, D.J. Fornari, M.R. Perfit, S.J. Goldstein, P. Johnson, D.J. DePaolo, and P. Michaels (2003). “Aberrant Youth: Chemical and isotopic constraints on the young off-axis lavas of the East Pacific Rise.” Geochemistry, Geophysics, Geosystems, 4, 10, 8621, doi:10.1029/2002GC000443.
Sims, K.W.W., S.R. Hart, M.K. Reagan, J. Blusztajn, H. Staudigel, R.A. Sohn, G.D. Layne, L.A. Ball and J. Andrews (2008). “238U-230Th-226Ra-210Pb-210Po, 232Th-228Ra and 235U-231Pa constraints on the ages and petrogenesis of Vailulu and Malumalu Lavas, Samoa.” Geochemistry, Geophysics, Geosystems, 9, Q04003. doi:10.1029/2007GC001651.
*Waters, C.L., K.W.W. Sims, E.M. Klein, S.M. White, M.K. Reagan, and G. Girard (2013). “Sill to Surface: Linking Young Off-Axis Volcanism with Subsurface Melt at the Overlapping Spreading Center at 9º03’N East Pacific Rise.” Earth and Planetary Science Letters, 369-370, 59-70. doi.org/10.1016/j.epsl.2013.03.006.
*Standish, J.J. and K.W.W. Sims (2010). “Young Volcanism and Rift Valley Construction at an Ultraslow Spreading Ridge.” Nature Geoscience, 3, 4, 286-292. doi: 10.1038/NGEO824.
Sohn, R.A. and K.W.W. Sims (2005). “Bending as a mechanism for triggering off-axis volcanism on the East Pacific Rise.” Geology, 33, 2, 93-96. doi: 10.1130/G21116.1.
*Waters, C.L., K.W.W. Sims, S.A. Soule, J. Blichert-Toft, N.W. Dunbar, T. Plank, R.A. Sohn, and M.A. Tivey (2013). “Recent Volcanic Accretion at 9-10ºN East Pacific Rise as Resolved by Combined Geochemical and Geological Observations.” Geochemistry, Geophysics, Geosystems, 14. doi: 10.1002/ggge.20134.
Shallow magmatic processes
Sims, K.W.W., S. Pichat, M.K. Reagan, P.R. Kyle, H. Dulaiova, N. Dunbar, J. Prytulak, G. Sawyer, G. Layne, J. Blichert-Toft, P.J. Gauthier, M.A. Charrette, and T.R. Elliott (2013). “On the timescales of magma genesis, melt evolution, crystal growth rates and magma degassing in the Erebus volcano magmatic system using the 238U, 235U- and 232Th-decay series.” Journal of Petrology, 54, 2, 235-271. doi: 10.1093/petrology/egs068.
Reagan, M.K., K.W.W. Sims, J. Enrich, R.B. Thomas, H. Cheng, R.L. Edwards, G.D. Layne, and L.A. Ball (2003). “Time-scale of differentiation from mafic parents to rhyolite in North American continental arcs.” Journal of Petrology, 44, 9, 1703-1726. doi: 10.1093/petrology/egg057
Giammanco, S., K.W.W. Sims, and S.M. Neri (2007). “Shallow rock stresses and gas transport at Mt. Etna (Italy) monitored through 220Rn, 222Rn and soil CO2 emissions in soil and fumaroles.” Geochem., Geophys., Geosys, 8, Q10001. doi:1029/2007GC00164.
*Chakrabarti, R., K.W.W. Sims; A.R Basu; M. Reagan; and J. Durieux (2009). “Timescales of Magmatic Processes and Eruption Ages of the Nyiragongo volcanics from 238U -230Th-226Ra-210Pb disequilibria.” Earth and Planetary Science Letters, 288, 149–157. doi:10.1016/j.epsl.2009.09.017.
Reubi, O., K.W.W. Sims, and B. Bourdon (2014). “238U-230Th equilibrium in arc magmas and implications for the time scales of mantle metasomatism.” Earth and Planetary Science Letters, 391, 146-158, doi.org/10.1016/j.epsl.2014.01.054.
Reubi, O. K.W.W. Sims, N. Varley, M. Reagan, and J. Eikenberg (2015) Timescales of degassing and conduit dynamics inferred from 210Pb-226Ra disequilibria in Volcan de Colima 1998-2010 andesitic magmas" (Caricchi, L. & Blundy, J. D. (eds) Chemical, Physical and Temporal Evolution of Magmatic Systems. Geological Society, London, Special Publications, 422, http://doi.org/10.1144/SP422.5).
Cooper, K., K.W.W. Sims, J.M. Eiler, N. Banerjee, (2016) Time scales of storage and recycling of crystal mush at Krafla Volcano, Iceland. Contributions to Mineralogy and Petrology, 171, 6, 54. doi 10.1007/s00410-016-1267-3.
Garrison, J. M., K.W.W. Sims, G.M Yogodzinski, R. D. Escobar, S. Scott, P. Mothes, Patricia, M. L. Hall, P. Ramon (2018) Shallow-level differentiation of phonolitic lavas from Sumaco Volcano, Ecuador. Contributions to Mineralogy and Petrology, 173, 6. DOI: 10.1007/s00410-017-1431-4).
Ocean chemistry and processes
Pichat, S., K.W.W. Sims, R. François, J.F. McManus, S. Brown-Legger, and F. Albarède (2004). “Lower export production during glacial periods in the equatorial Pacific as derived from (231Pa/230Th) measurements in deep-sea sediments.” Paleoceanography, 19, 4023. doi: 10.1029/2003PA000994.
*Owens, S.A., K.O. Buesseler, K.W.W.Sims (2011). “Re-evaluating the 238U-salinity relationship in seawater: Implications for the 238U-234Th disequilibrium method.” Marine Chemistry, 127, 1-4, 20, Pages 31–39. doi:10.1016/j.marchem.2011.07.005.
*Arendt C.A. S.M. Aciego, K. W. W. Sims, S B. Das, C. Sheik, E. I. Stevenson (2018) Greenland subglacial water and proximal seawater U chemistry: Implications for seawater δ234U on glacial-interglacial timescales. Geochimica et Cosmochimica Acta, 225, 102-115, doi.org/10.1016/j.gca.2018.01.007.
Crustal dynamics and processes
Sims, K.W.W., R.P. Ackert, Jr., F. Ramos, R.A. Sohn, M.T. Murrell, and D. J. DePaolo (2007). “Determining eruption ages and erosion rates of Quaternary basaltic volcanism from combined U-series disequilibria and cosmogenic exposure ages.” Geology, 35, 471-474, doi:10.1130/G23381A.1.
*Mervine, E.M., K.W.W. Sims, S.E. Humphris, and P.B. Kelemen (2015). "The applications and limitations of U-Th disequilbria systematics for determining rates of peridotite carbonation in the Samail Ophiolite, Sultanate of Oman." Chemical Geology, 412, 151-166, .org/10.1016/j.chemgeo.2015.07.023
*Arendt, C.A. S. M. Aciego, K.W.W. Sims, and S. M. Aarons (2017) Seasonal Progression of Uranium Series Isotopes in Subglacial Meltwater: Implications for Subglacial Storage Time. Chemical Geology, 467, 42-52, https://doi.org/10.1016/j.chemgeo.2017.07.007.
*Scott, S.R., K. W.W. Sims, B. R. Frost, P. B. Kelemen ,K. A. Evans, and S. Swapp (2017) On the hydration of olivine in ultramafic rocks: Implications from Fe isotopes in serpentinites” (Geochemica Cosmochimica Acta, 215, 105-215, https://doi.org/10.1016/j.gca.2017.07.011
Core formation and planetary differentiation
Newsom, H.E. and K.W.W. Sims (1991). “Core formation during early accretion of the Earth.” Science, 252, 926-933. doi: 10.1126/science.252.5008.926.
Sims, K.W.W., H.E. Newsom, and E.S. Gladney (1990). “Chemical fractionation during formation of the Earth’s core and continental crust: Clues from As, Sb, W and Mo.” In Origin of the Earth, J. Jones and H.E. Newsom (eds.), New York: Oxford University Press; Houston. Lunar and Planetary Institute. .
Newsom, H.E., K.W.W. Sims, P.D. Noll, W.L. Jaeger, S.A. Maehr, and T.B. Bassera (1996). “The depletion of W in the bulk-silicate Earth: constraints on core formation.” Geochimica et Cosmochimica Acta, 60, 7, 1155-1169. doi: 10.1016/0016-7037(96)00029-4.
Development of novel analytical protocols
Sims, K.W.W., J. Gill, A. Dossetto, D. Hoffmann, C.C. Lundstom, R. Williams, L.A. Ball, D. Tollstrup, S.P. Turner, J. Prytulak, J. Glessner, J.J. Standish, and T. Elliott (2008). “An inter-laboratory assessment of the Th Isotopic Composition of Synthetic and Rock standards.” Geostandards and Analytical Research, 32, 1, 65-91. doi: 10.1111/j.1751-908X.2008.00870.x.
Ball, L.A., K.W.W. Sims, and J. Schwieters (2008). “Measurement of 234U/238U and 230Th/232Th in volcanic rocks using the Neptune PIMMS.” Journal Analytical Atomic Spectrometry, 23, 173-180. doi: 10.1039/b703193a.
Layne, G.D. and K.W.W. Sims (2000). “Analysis of 232Th/230Th in volcanic rocks by Secondary Ionization Mass Spectrometry.” International Journal of Mass Spectrometry, 203, 1-3, 187-198.
Dulaiova, H., K.W.W. Sims, and M.A. Charette (2013). “A new method for the determination of low-level actinium-227 in geological samples.” Journal of RadioAnalytical and Nuclear Chemistry, 296, 279-283. doi:10.1007/s10967-012-2140-0.)
Lane-Smith, D. and K.W.W. Sims (2013). “The effect of CO2 on the measurement of 220Rn and 222Rn, with instruments utilizing electrostatic precipitation.” Acta Geophysica, 61, 4, 822-830 (Special volume on Geo-Hazards; Guest editor: Rakesh Chand Ramola) doi: 10.2478/s11600-013-0107-3.
Sims, K.W.W., and E.S. Gladney (1991). “Determination of As, Sb, W and Mo in silicate matrices by epithermal neutron activation and inorganic ion exchange.” Analytica Chimica Acta, 251, 297-303. doi: 10.1016/0003-2670(91)87150-6.
Sims, K.W.W., E.S. Gladney, C.C. Lundstrom, and N.W. Bower (1988). “Elemental concentrations in Japanese silicate rock standards: a comparison with the literature.” Geostandards Newsletter, 12, 379-389.
Choi, M.S., R. Francois, K.W.W. Sims, M.P. Bacon, S. Legger-Brown, A.P. Fleer, L.A. Ball, D. Schneider, and S. Pichat (2001). “Rapid determination of 230Th and 231Pa in seawater by Inductively coupled plasma mass spectrometry.” Marine Chemistry, 76, 99-112.
Select climbs
High altitude alpine climbing
Peru, Cordillera Blanca
Nevado Huascaran Sur (6768 meters). The West Face via The Shield (Solo); Nevado Chacraraju (6112 meters) South Face via American Direct; Nevado Artesonraju (6025 meters) Southwest Face (Solo); Nevado Tocllaraju (6032 meters); Nevado Chopicalqi (6354 meters); Nevado Copa (6188 meters); Nevada Wamashraju (5434 meters),West Face via Sims-Hanning Route (V,5.10+) First Ascent.
Ecuadorian volcanoes
Chimborazo (6263 meters); Cayambe (5790 meters); Sangay (5300 meters).
Alaska, Alaska range
Denali (20,320 feet). West Buttress (as a guide); Moose's Tooth- West Ridge.
Ice climbing
Scotland
Ben Nevis (4,406 feet). North Face. Orion Face Direct Grade VI, Point Five Gully Grade V (Solo), Zero Gully Grade V (Solo). Craig Megaiduh (3,658 feet). North Face, North Post Gully Grade V (Solo).
Colorado
Bridalveil Falls Grade VI, Ames Falls Grade VI, Skylight Grade V, The Squid Grade VI.
Utah
Stairway to Heaven Grade V, Great White Icicle Grade IV.
Northeastern United States
The Promenade Grade VI, Repentance Grade VI, The Black Dike Grade IV.
Rock climbing
Yosemite Valley, California
El Capitan Pacific Ocean Wall VI 5.10 A5, Salathe Wall VI 5.11 A3, Nose VI, 5.11A1. Half Dome North West Face VI 5.11 A1 (6-hours, simultaneously climbing and almost all free); The Rostrum IV 5.11; Washington Column, Astroman IV 5.11 (one day combined ascent).
Black Canyon of the Gunnison, Colorado
North Chasm View Wall Air Voyage V 5.12+ (First Free Ascent), Scenic Cruise IV 5.10; Journey Home IV, 5.10R; South Chasm View Wall Mirror Wall IV 5.11, Black Jack III 5.10. Painted Wall Southern Arete V 5.10, Mordor Wall VI 5.10 A4.
Longs Peak (14,110 feet), Rocky Mountain National Park, Colorado
The Diamond Grand Traverse, Yellow Wall V 5.9 A3 (Winter Ascent), Casual Route VI, 5.9.
Canyon Country
The Witch, Sims-Hesse-Hanning Route, III 5.11+ R (First Free Ascent); Charlie Horse Needle, Sims-Hesse-Hanning Route, II 5.11 or 5.12a (First Free Ascent); Argon Tower, Arches National Park, III 5.11+, West Face (First Free Ascent); Cochina Spire, Zuni Reservation, III 5.11+ A0, West Face (First Ascent of Tower).
Resources
University of Wyoming faculty
Living people
1960 births
American geochemists
People from Colorado Springs, Colorado | Kenneth Sims (geologist) | [
"Chemistry"
] | 6,765 | [
"Geochemists",
"American geochemists"
] |
53,175,008 | https://en.wikipedia.org/wiki/Kim%20TallBear | Kim TallBear (born 1968) is a Sisseton Wahpeton Oyate professor at the University of Alberta, specializing in racial politics in science. Holding the first ever Canada Research Chair in Indigenous Peoples, Technoscience and Environment, TallBear has published on DNA testing, race science and Indigenous identities, as well as on polyamory as a decolonization practice.
Early life
TallBear was born in 1968 at a public hospital in Pipestone, Minnesota. She grew up moving back and forth between the Sisseton and Flandreau reservations in South Dakota. During this time, she was mostly raised by her maternal grandmother and great-grandmother, until the age of fourteen when she went to live full time with her mother in St. Paul, Minnesota.
TallBear is a citizen of the Sisseton-Wahpeton Oyate in South Dakota, as well as a descendant from the Cheyenne and Arapaho tribes of Oklahoma through her maternal grandfather. Her Indigenous descent comes from her mother’s side. She also has some Cree and Métis ancestry from Canada. Her father, who was only present in her life up to age three, is white. TallBear has two sisters and one brother, whose father is Floyd Westerman, a Dakota Sioux musician, actor and political activist.
TallBear’s household growing up was a politically active environment and TallBear says her mother in particular helped to shape her understanding of research and academic thought as being a part of a colonial project. Nevertheless her mother also emphasized thinking practically about education, viewing it as the only way out of poverty.
Education and career
TallBear pursued post-secondary education at the University of Massachusetts in Boston obtaining an undergraduate degree in community planning. She then completed her master’s degree in environmental planning at Massachusetts Institute of Technology.
After graduating, TallBear worked for 10 years as an environmental planner for United States federal agencies, tribal governments, and national tribal organizations. She later worked for a non-governmental, Indigenous environmental research organization in Denver. This organization started holding workshops that researched the implications of mapping of the human genome and the genetic research on Indigenous peoples. It was through this workshop that TallBear found a desire to continue her education, and subsequently completed her PhD at the University of California, Santa Cruz in History of Consciousness in 2005.
In 2010, TallBear was elected to be a member of the Council of the Native American and Indigenous Studies Association (NAISA), and served in the position until 2013. In late 2016, she became the first ever Canada Research Chair in Indigenous Peoples, Technoscience and Environment. As she is an anthropologist specializing in the cultural intersection of science and technology, TallBear is a frequent media commentator on issues of Tribal membership, genetics and identity.
She has taught in the Native Studies department of the University of Alberta since 2014, and has been a full professor since 2020.
Areas of study
DNA and Indigenous identities
TallBear’s first book, Native American DNA: Tribal Belonging and the False Promise of Genetic Science, was released in 2013 by the University of Minnesota Press. Described as a "provocative and incisive work of interdisciplinary scholarship", the book examines the science of hereditary genetics and the problematic consequences for Indigenous identities. Specifically, TallBear’s critique focuses on the ways the language employed by genetic scientists—and its subsequent marketing of DNA testing—can reduce what it means to be Indigenous to genetically determined characteristics. TallBear’s research shows how this often relies on traditions of scientific racism historically directed at Indigenous populations. The assertion of genetic determinism, TallBear argues, is often at odds with generations of cultural traditions Indigenous communities have used to collectively self-identify—traditions that focus on relationships, and shared value systems negotiated by social relations.
TallBear's work documents Indigenous communities across a diverse range of contexts in order to demonstrate the ways Indigenous identities are muted and amplified to the advantage of settler populations. In defending the ethics of Indigenous jurisdiction over their own identities, TallBear argues Indigenous Peoples know their history better than settlers. In light of this, TallBear has drawn attention to the problems of the settler scientific community attempting to direct the boundaries of Indigenous identities. TallBear points to the history of the scientific community negatively impacting Indigenous communities as a reason for researchers to approach issues of Indigenous identity with deep care and respect for these histories. TallBear has criticized researchers who do not invest considerable time in building relationships with the Indigenous populations with which they wish to study. For TallBear, the need for embedded research stems from the important role cultural practices and specific relational contexts play in shaping Indigenous identity.
Critiques of Elizabeth Warren's claims to Indigenous ancestry
In 2018, Senator Elizabeth Warren released the results of a DNA test to prove her claim to Cherokee Native American ancestry. This raised many questions surrounding how one can claim Native American ancestry and who can decide if these claims are true or false.
In Native American DNA: Tribal Belonging and the False Promise of Genetic Science, TallBear argues that genetic testing is a scientifically unreliable method. Since much of her work coincides with much of this situation, TallBear published a post to her Twitter in 2018 titled, “Statement on Elizabeth Warren’s DNA Test”. In the statement, she claims the situation ultimately as settler-colonial definitions of who is Indigenous.
TallBear and Cherokee Nation community members have defended their arguments by explaining how tribal governments do not use genetic ancestry tests, instead using forms of biological and political relationships to define their citizenries. Despite the Cherokee Nation community members challenging Warren’s claims, and TallBear’s academic research and work on the subject, Warren initially defended her ancestry claims. She later apologized.
"The Critical Polyamorist" and decolonizing relationships
In her later work, TallBear is focused on sexuality, specifically on decolonizing the valourization of monogamy that she characterizes as emblematic of "settler sexualities". She pursued this topic of study through a blog written under an alter ego, "The Critical Polyamorist". TallBear was part of a panel discussing decolonizing institutions such as relationships, at the National Women's Studies Association meeting in 2016.
TallBear's critiques of monogamous, heteronormative colonial relations focus on their incompatibility with an environmentally sustainable world. For TallBear, moving beyond the current environmental problems of the neoliberal nation state requires expanding understandings and practices of kinship. She argues Indigenous conceptions of kin provide opportunities for this transition. TallBear’s critical polyamory places emphasis on looking beyond human-centric intimacy to also incorporate relational ways of being with place and other non-human dimensions to relationships. TallBear’s focus on kin goes to the “decolonization” of intimacy: relationships outside of what she describes as settler-colonial relationship structures.
Selected works
Articles
"Dossier: Theorizing Queer Inhumanisms: An Indigenous Reflection on Working Beyond the Human/Not Human" in GLQ: A Journal of Lesbian and Gay Studies, Vol. 21(2-3), 2015: 230–235.
"The Emergence, Politics, and Marketplace of Native American DNA" in The Routledge Handbook of Science, Technology, and Society, eds. Daniel Lee Kleinman and Kelly Moore. London: Routledge, 2014: 21–37.
"Tribal Housing, Co-Design & Cultural Sovereignty" in Edmunds, David S., Ryan Shelby, Angela James, Lenora Steele, Michelle Baker, Yael Valerie Perez, and Kim TallBear Science, Technology, & Human Values 38 (6) (2013): 801–828.
"Genomic Articulations of Indigeneity" in Social Studies of Science 43(4) (August 2013): 509–534.
"Your DNA is Our History." Genomics, Anthropology, and the Construction of Whiteness as Property," co-authored with Jenny Reardon in Current Anthropology 53(S12) (April 2012): S233–S245.
"The Illusive Gold Standard in Genetic Ancestry Testing," co-authored with Lee, S. S-J., D. Bolnick, T. Duster, P. Ossorio in Science 325 (5943) (July 3, 2009): 38–39.
"Commentary" (on Decoding Implications of the Genographic Project for Archaeology and Cultural Heritage)" in International Journal of Cultural Property 16 (2009): 189–192
"The Science and Business of Genetic Ancestry," co-authored with Bolnick, Deborah A., Duana Fullwiley, Troy Duster, Richard S. Cooper, Joan H. Fujimura, Jonathan Kahn, Jay Kaufman, Jonathan Marks, Ann Morning, Alondra Nelson, Pilar Ossorio, Jenny Reardon, and Susan M. Reverby in Science, 318(5849) (October 19, 2007): 399–400
"Narratives of Race and Indigeneity in the Genographic Project" in Journal of Law, Medicine & Ethics, Vol. 35(3) (Fall 2007): 412–424.
Books
"Beyond the Life/Not Life Binary: A Feminist-Indigenous Reading of Cryopreservation, Interspecies Thinking and the New Materialisms." in Joanna Radin and Emma Kowal's edited Cryopolitics, published 2017 by MIT Press
"Dear Indigenous Studies, It's Not Me, It's You. Why I Left and What Needs to Change." in Aileen Moreton-Robinson's edited Critical Indigenous Studies: Engagements in First World Locations, published 2016 by Tucson: University of Arizona Press, 2016: 69–82
Native American DNA: Tribal Belonging and the False Promise of Genetic Science, published 2013 by Minneapolis: University of Minnesota Press
“DNA, Blood and Racializing the Tribe,” in Jayne O. Ifekwunige's ‘Mixed Race’ Studies: A Reader, published 2003 in Wicazo Sá Review Vol. 18(1) (2003): 81–107, then in 2004 by London and New York: Routledge
References
External links
Kim TallBear's website
TallBear addresses issues in advancing science and technology opportunities for Indigenous communities in this 2018 RED Talk: Shaping Tribal Identities.
1968 births
Living people
Cheyenne and Arapaho Tribes
Native American academics
Native American women academics
American women academics
University of Massachusetts Boston alumni
MIT School of Architecture and Planning alumni
University of California, Santa Cruz alumni
Academic staff of the University of Alberta
Science and technology studies scholars
Sisseton Wahpeton Oyate people
Indigenous studies in Canada
Polyamorous people
21st-century American women
Academics from Minnesota
American people of First Nations descent
American people of Cree descent
American people of Métis descent | Kim TallBear | [
"Technology"
] | 2,218 | [
"Science and technology studies",
"Science and technology studies scholars"
] |
53,175,530 | https://en.wikipedia.org/wiki/Sadad%20Ibrahim%20Al%20Husseini | Sadad Ibrahim Al Husseini () is a leading Saudi oil and gas industry expert. He is most widely known for his achievements during his tenure at Saudi Aramco as the Senior and Executive Vice President for Exploration and Producing, and his current work on supply side risk; referred to by the New York Times as "one of the most respected and accomplished oilmen in the world".
Summary
Sadad Ibrahim Al Husseini is credited with launching the field modernization and state of art reservoir management and development of Saudi Arabia's giant oil fields, the upgrading of the company's drilling, environmental, and upstream safety standards, the discovery and development of its Paleozoic oil and gas reservoirs, the discovery of its Red Sea oil and condensate fields, the initiation of its upstream advanced degree and specialists professional programs, and the development of its leading edge reservoir modelling and simulation capabilities at its purpose built Exploration and Petroleum Engineering Center, EXPEC. In 1988 he launched Aramco's mothballing program for 3.5 million barrels of oil production capacity and in 1990, as a result of the Iraqi invasion of Kuwait, he led the Aramco team that re-activated the mothballed capacity thereby increasing Kingdom's oil production from 5 million bd to 8.5 million bd within six months. In 1994 he launched the intensified non-associated Saudi gas exploration program which increased the Kingdom's non-associated gas reserves by 30 Tcf within 4 years.
In 1996, Al Husseini was called upon by HM King Abdullah ibn Abdul Aziz to provide advisory support to the Kingdom's leadership for the purpose of expanding its economy through a broader exploitation of its proven gas reserves. This culminated in the Kingdom's Natural Gas Initiative in 1999 which invited international oil companies to participate in the development of the Kingdom's non-associated gas reservoirs and the expansion of its power generation, desalination and petrochemical sectors. Following on his retirement from Saudi Aramco in 2004, Dr. Al Husseini co-founded and is president of Husseini Energy Company, a highly specialized oil and gas consulting firm based in Bahrain and Saudi Arabia.
On July 30, 2018, Al Husseini said, "Rather than allowing these hostile maneuvers to go unnoticed in the eyes of the world, the Saudi (energy) minister has placed Iran's subversions of the whole global economy under the spotlight for everyone to see," "The capture of the port of Hodeidah will go a long way towards putting an end to these disruptions".
Early life
Al Husseini was born in Damascus in 1946 to Col. Ibrahim Abdulrahman Al Husseini and Myassar BachImam. His father was a leading Syrian nationalist and member of the Syrian military and political leadership until 1957. Al Husseini attended primary and secondary education at Notre Dame International School in Rome, Italy between 1955 and 1964. He and his family moved to Saudi Arabia in 1961 when King Faisal bin Abdul Aziz invited Col. Ibrahim Al Husseini to advise the Saudi Arabian Council of Ministers on national security matters and to support Prince Abdullah bin Abdul Aziz Al Saud as his special advisor in the establishment of the modern Saudi Arabian National Guard.
Wikileaks
On February 8, 2011 The Guardian newspaper published US cables from Saudi Arabia that were obtained by WikiLeaks. The cables were based on a conversation attributed to Dr Sadad Al Husseini in 2007 claiming Dr Husseini thought members of Aramco management were confusing probable resources with proven reserves and were therefore causing an overstatement of the proven reserves estimates by as much as 300 billion barrels. The difference between probable resources and proven reserves was not clarified in the news reports and the story gained traction in the press outside the Kingdom. Dr Sadad Al Husseini maintained that the US cable gravely misrepresented his opinion and that the report was full of errors and mistakes including quoting resource figures as reserve. Subsequently, Dr Sadad Al Husseini's firm published a press release on February 9, 2011, in response to the significant errors in the cable and clarified Dr Sadad's position on Saudi Arabia's proven reserves and production capabilities.
References
The Arabian Sun, Vol. LVI, No. 27, July 11, 2001
The New York Times Aug 21, 2005
External links
The American Institute of Mining, Metallurgical, and Petroleum Engineers (AIME)
1946 births
Living people
Brown University alumni
Saudi Arabian businesspeople
Saudi Arabian people of Syrian descent
Syrian businesspeople
Saudi Aramco
Petroleum industry | Sadad Ibrahim Al Husseini | [
"Chemistry"
] | 918 | [
"Chemical process engineering",
"Petroleum",
"Petroleum industry"
] |
53,176,203 | https://en.wikipedia.org/wiki/Obash | Obash is a bash script obfuscator written in the C programming language. obash encodes and encrypts bash shell scripts into executable binaries much like shc, the project that inspired it, but uses AES-256 encryption and the key and initialization vector are retrieved from the hardware instead of being hard coded into the binary itself. The obash project was started to address some of the issues that affect shc, the main one being able to see the original shell script source by simply issuing ps -ef. Although the objectives are the same, obash shares no code with shc and was built from scratch from the ground up, any code similarities are purely accidental and dictated by the shared objectives.
Obash is still a work in progress but the master branch on GitHub generally has usable sources while the testing branch may be in a transition state at any given time.
How it works internally
Obash takes the input script and AES-256 encrypts it, and also base64 encodes the AES ciphertext so that it can be used to declare an unsigned char array.
It then produces an intermediate C file which is basically the interpreter (see interpreter.c), functions, text array containing the ciphertext, the optional key and IV for reusable binaries (not bound to the hardware) and the main. The intermediate C file is then compiled into an executable.
The intermediate C file is built in the following manner (see mk_sh_c function in functions.c):
includes block from interpreter.h
crypted_script variable containing the AES-256 encrypted script encoded via base64
serial and uuid variables (empty if non reusable)
functions block from interpreter.h
main_body block from interpreter.h
See recreate_interpreter_header script for details on how interpreter.h is created from interpreter.c.
Key and initialization vector for AES-256 encryption
The key and IV are not hard-coded into the binary (unless you decide to build a reusable static binary with the -r flag) but are retrieved each time from the hardware (hence binding it to a machine). In case of a reusable static binary (built with the -r flag) then the uuid and serial are in the binary itself but will be manipulated anyway by makekey and makeiv so that they are not usable immediately should anyone ever inspect the binary itself.
Although the whereabouts from where the serial and uuid are retrieved is traceable and is not a secret (machine uuid and serial number for non reusable and random hex digits for reusable) these should be then manipulated in a way that they are not directly usable as is. In the code there is a comment suggesting where this should be done (see makekey and makeiv functions in functions.c): each and every one of you using obash is encouraged to do so or it would be fairly easy to extract the script source from the obfuscated binary.. In the distributed code, as an example, the "-" are stripped from the uuid and the serial is padded to reach the suggested length for the cipher used.
Alternatives
CCsh
shellcrypt
shc
References
External links
https://github.com/louigi600/obash
Unix software
Software obfuscation | Obash | [
"Technology",
"Engineering"
] | 695 | [
"Cybersecurity engineering",
"Software obfuscation"
] |
53,177,263 | https://en.wikipedia.org/wiki/NGC%207640 | NGC 7640 is a barred spiral galaxy in the constellation of Andromeda. Discovered on October 17, 1786 by the English astronomer William Herschel. The galaxy has an 11th visible magnitude and is located about 30 million light-years from Earth.
NGC 7640 might not look much like a spiral, but this is due to the orientation (edge on) of the galaxy with respect to an observer on Earth. There is evidence that this galaxy has experienced an interaction with another galaxy in the (astronomically) recent past.
References
External links
Andromeda (constellation)
7640
Barred spiral galaxies | NGC 7640 | [
"Astronomy"
] | 120 | [
"Andromeda (constellation)",
"Constellations"
] |
53,177,930 | https://en.wikipedia.org/wiki/Viorel%20P.%20Barbu | Viorel P. Barbu (born 14 June 1941) is a Romanian mathematician, specializing in partial differential equations, control theory, and stochastic differential equations.
Biography
He was born in Deleni, Vaslui County, Romania. He attended the Mihail Kogălniceanu High School in Vaslui and then the Costache Negruzzi National College in Iași. Barbu completed his undergraduate degree at the Alexandru Ioan Cuza University of Iași in 1964, and his Ph.D. at the same university in 1969. His doctoral advisor was Adolf Haimovici; his dissertation thesis was titled Regularity Theory of Pseudodifferential Operators. He became a professor at the University of Iași in 1980.
In 1993, he was elected a titular member of the Romanian Academy. In 2011 he was awarded the Order of the Star of Romania, Knight rank by President Traian Băsescu.
Bibliography
Some of his books and papers are:
Analysis And Control Of Nonlinear Infinite Dimensional Systems
Optimization, Optimal Control and Partial Differential Equations
Nonlinear semigroups and differential equations in Banach spaces
Hamilton-Jacobi Equations on Hilbert Space
Stochastic Porous Media Equations
Nonlinear Differential Equations of Monotone Types in Banach Spaces
Convexity and Optimization in Banach Spaces
Optimal Control of Variational Inequalities
References
External links
1941 births
People from Vaslui County
Romanian mathematicians
Alexandru Ioan Cuza University alumni
Academic staff of Alexandru Ioan Cuza University
Titular members of the Romanian Academy
Living people
Control theorists
Knights of the Order of the Star of Romania
Costache Negruzzi National College alumni
Partial differential equation theorists | Viorel P. Barbu | [
"Engineering"
] | 337 | [
"Control engineering",
"Control theorists"
] |
53,178,099 | https://en.wikipedia.org/wiki/Color%20Genomics | Color Health, Inc. (founded as Color Genomics) makes population-scale cancer detection and care accessible, convenient, and cost-effective for employers, health plans, and unions. With nearly a decade of experience, Color has served millions of patients and partnered with innovators such as the National Institutes of Health, the CDC, large public health departments, and more.
Color’s cancer detection and management solution, built in partnership with the American Cancer Society, is a comprehensive, integrated care model that supports individuals from screening to diagnosis and care. Color provides risk education and assessment, accessible screenings, a nationwide clinical care network, and ongoing educational programming to help individuals and organizations take control of cancer.
History
The company was co-founded in 2015 by Elad Gil, Nish Bhat, Taylor Sittler, and Othman Laraki, who is the CEO, in Burlingame, California.
In November 2021, the company had a valuation of $4.6B and collected $100 million in a series E financing round.
Expansion to population health
Color provides technology, software, and clinical services for population health programs.
Color has partnered with health systems including NorthShore University Health System, Ochsner Health System, and Jefferson Health.
COVID-19 testing programs
In early 2020, recognizing the growing threat that the COVID-19 pandemic presented, Color mobilized its existing software, logistics expertise and lab operations to focus on mass COVID-19 testing.
Color operates a high-throughput CLIA-certified COVID-19 testing laboratory and processes thousands of samples a day. The integrated process includes sign up, the self-collection kit, and results returned via text and email to patients, clinicians, and public health authorities. Color returns results, on average, within 24–48 hours.
In August 2020, Color was running some of the highest-capacity test sites in the country. Color was also responsible for the majority of San Francisco’s COVID-19 testing with an average turnaround time within 24 hours, and most results returned in under 48 hours. Color worked with San Francisco’s CityTestSF program, Alameda County Health Services and federally qualified health centers in Alameda County, Marin County and others. The company has also partnered with a wide variety of universities, employers and public health entities, including USC and United Airlines.
In January 2022, Color had computer difficulties that resulted in delayed test results and closed testing stations.
Testing system
Genetics
Color’s physician-ordered test can be initiated by individuals online, and a sample collection kit is sent in the mail. Individuals provide a saliva sample and return the kit in a pre-paid package. Color's CLIA-certified and CAP-approved lab analyzes for variants in the breast cancer genes BRCA1 and BRCA2, as well as 28 other genes associated with breast, prostate, colon, uterine, stomach, melanoma, pancreatic, and ovarian cancers. The test also identifies variants in 30 genes related to hereditary heart conditions as well as genes that may impact medication response. Genetic counseling with board-certified genetic counselors is available for free to all individuals who use Color.
COVID-19
Color’s FDA Emergency Use Authorization (EUA) COVID-19 test can be accessed as a part of testing programs initiated by a public health entity, university, employer or other organization. The test is a dry anterior nasal swab, approved for use either in an on-site or at-home setting without the need for a healthcare provider to monitor sample collection, which eases the burden on the healthcare system and reduces testing costs.
The company has received an FDA EUA for the testing assay, which is a nucleic acid amplification method called LAMP, or loop-mediated isothermal amplification. This enables processing test results 50% faster than RT-PCR, the amplification method used at most other labs. LAMP relies on a different set of chemical reagents than standard PCR tests, which helps the process avoids supply chain scarcity.
Research
In 2018, Color was selected, alongside the Broad Institute of MIT and Harvard, and the Laboratory for Molecular Medicine (LMM) at Partners HealthCare, to establish one of three genome centers around the country for the National Institutes of Health’s historic All of Us Research Program. All of Us will sequence one million or more people across the US, with the goal of accelerating health research and enabling individualized prevention, treatment, and care. The program has a focus on recruitment from populations that have been historically underrepresented in clinical science and genomic medicine, in order to build a diverse biomedical data resource that provides a foundation for better insights into the biological, environmental, and behavioral factors that influence health.
In 2019, Color was named the sole awardee to deliver all of the genetic counseling for All of Us. As the awardee, Color will customize software and tools to integrate data from all the genome centers, standardize reporting across the program, and ensure all results are returned in a unified way. This is a first year $4.6 million grant as part of a multi-year $25 million project.
In collaboration with the Women’s Health Initiative and Dr. Mary-Claire King at the University of Washington, Color provided genetic sequencing for the cohort of 10,000 Fabulous Ladies Over Seventy (FLOSSIES). This is the largest publicly available dataset of genetic variants associated with hereditary cancer in healthy, older individuals.
Color Data, a database containing aggregated genetic and clinical information from 50,000 individuals who took a Color test, helps researchers and scientists identify genotype-phenotype correlations and novel variants for functional analysis, as well as enables data-driven drug discovery and development. It is the largest public database of its kind.
As a part of the MAGENTA Study, which aims to improve availability of genetic testing for hereditary cancer syndromes to at-risk individuals through the use of an online genetic testing service, Color is working with a Stand Up to Cancer Dream Team that includes physicians, scientists and researchers from the MD Anderson Cancer Center and the University of Washington to provide genetic counseling to high-risk individuals through delivery models such as tele-counseling.
In collaboration with Dr. Laura Esserman at University of California and Sanford Health, Color is providing genetic testing for WISDOM, a 100,000-woman study that is comparing annual screenings with personalized, risk-based breast cancer screenings.
As part of the GENtleMEN Study, Color is working with Dr. Heather Cheng at the Fred Hutchinson Cancer Research Center and the University of Washington to provide genetic testing and counseling to men with advanced prostate cancer.
Color contributes anonymized variants to ClinVar, a free database managed by the National Center for Biotechnology Information (NCBI) at the National Institutes of Health (NIH) that helps researchers identify links between genes and disease.
Color's research collaborators include:
Mary-Claire King: advisor, scientific collaborator
Sekar Kathiresan: advisor, scientific collaborator
Heidi Rehm: scientific collaborator
References
Genomics companies
Medical tests
Biotechnology
Cancer research
Companies based in Burlingame, California
American companies established in 2015
2015 establishments in California
Privately held companies based in California | Color Genomics | [
"Biology"
] | 1,467 | [
"nan",
"Biotechnology"
] |
53,178,754 | https://en.wikipedia.org/wiki/Thermonasty | In plant biology, thermonasty is a nondirectional response to temperature in plants. It is a form of nastic movement, not to be confused with thermotropism, which is a directional response in plants to temperature. A common example of this is in some Rhododendron species, but thermonasty has also been observed in other plants, such as Phryma leptostachya. Flower opening in certain crocus and tulip species is also known to be thermonastic. These movements are thought to be regulated by having unequal cell elongation in certain plant tissues, causing different tissues to bend. In other processes, like in the temperature regulation of flower openings, movement has instead been shown to be a result of irreversible cell growth, a growth type not typically associated with plant movement. Furthermore, thermonasty has been shown to be independent of other environmental signals, such as light and gravity.
Thermonasty is generally considered to be an adaptation for protection against colder temperatures. It is hypothesized that thermonastic movement is an adaptation for photoprotection, as harsh freezing conditions make leaves more susceptible to light damage from the sun. In flowers it may instead serve as a signal for flower opening and closing with rising and falling temperatures. Although the exact mechanism for thermonasty is still not fully understood, there has been research conducted to reveal more.
Thermonasty in Rhododendron
In some species of Rhododendron, thermonasty is as well-known phenomenon during the winter months. The leaves can be seen to droop from their branches and curl inwards under freezing temperatures. A research group from Iowa State University tried to determine if water transport proteins, aquaporins, were involved with curling in Rhododendron leaves. They took leaves from a thermonastic and non-thermonastic Rhododendron and subjected them to freezing and thawing conditions, sampling their RNA levels for their target aquaporins at specific time points. They did this to see if there was any change in the expression levels of aquaporins during changes in temperatures in association with thermonastic curling.
They concluded that expression of aquaporins decreases during the initial freezing stages, but in both species the proteins were then up-regulated as the temperature continued to drop. The researchers concluded that there may be some association with aquaporins to thermonasty, but they could not conclude what kind of association that is. They were, however, able to support a previous hypothesis that extracellular freezing is required for the thermonastic curling response. They exposed leaves from the thermonastic Rhododendron species to freezing temperatures, but some leaves had water that froze on the surface, and others did not. Leaves with extracellular water freezing curled at a higher temperature than leaves without, indicating that the extracellular freezing was necessary for curling at a higher temperature.
References
Plant physiology | Thermonasty | [
"Biology"
] | 620 | [
"Plant physiology",
"Plants"
] |
53,179,065 | https://en.wikipedia.org/wiki/List%20of%20stellar%20explosion%20types | Stellar explosion can refer to:
Nova
Kilonova
Micronova
Supernova
Type Ia supernova
Type Ib and Ic supernovae
Type II supernova
Superluminous supernova
Pair-instability supernova
Hypernova
Supernova impostor, stellar explosions that appear similar to supernova, but do not destroy their progenitor stars
Failed supernova
Luminous red nova, an explosion thought to be caused by stellar collision
Solar flares are a minor type of stellar explosion
Tidal disruption event, the pulling apart of a star by tidal forces
References
Stellar phenomena | List of stellar explosion types | [
"Physics"
] | 110 | [
"Physical phenomena",
"Stellar phenomena"
] |
53,179,717 | https://en.wikipedia.org/wiki/Capitanian%20mass%20extinction%20event | The Capitanian mass extinction event, also known as the end-Guadalupian extinction event, the Guadalupian-Lopingian boundary mass extinction, the pre-Lopingian crisis, or the Middle Permian extinction, was an extinction event that predated the infamous end-Permian extinction. The mass extinction occurred during a period of decreased species richness and increased extinction rates near the end of the Middle Permian, also known as the Guadalupian epoch. It is often called the end-Guadalupian extinction event because of its initial recognition between the Guadalupian and Lopingian series; however, more refined stratigraphic study suggests that extinction peaks in many taxonomic groups occurred within the Guadalupian, in the latter half of the Capitanian age. The extinction event has been argued to have begun around 262 million years ago with the Late Guadalupian crisis, though its most intense pulse occurred 259 million years ago in what is known as the Guadalupian-Lopingian boundary event.
Having historically been considered as part of the end-Permian extinction event, and only viewed as separate relatively recently, this mass extinction is believed to be the third largest of the Phanerozoic in terms of the percentage of species lost, after the end-Permian and Late Ordovician mass extinctions, respectively, while being the fifth worst in terms of ecological severity. The global nature of the Capitanian mass extinction has been called into question by some palaeontologists as a result of some analyses finding it to have affected only low-latitude taxa in the Northern Hemisphere.
Magnitude
In the aftermath of Olson's Extinction, global diversity rose during the Capitanian. This was probably the result of disaster taxa replacing extinct guilds. The Capitanian mass extinction greatly reduced disparity (the range of different guilds); eight guilds were lost. It impacted the diversity within individual communities more severely than the Permian–Triassic extinction event. Although faunas began recovery immediately after the Capitanian extinction event, rebuilding complex trophic structures and refilling guilds, diversity and disparity fell further until the boundary.
Marine ecosystems
The impact of the Capitanian extinction event on marine ecosystems is still heavily debated by palaeontologists. Early estimates indicated a loss of marine invertebrate genera between 35 and 47%, while an estimate published in 2016 suggested a loss of 33–35% of marine genera when corrected for background extinction, the Signor–Lipps effect and clustering of extinctions in certain taxa. The loss of marine invertebrates during the Capitanian mass extinction was comparable in magnitude to the Cretaceous–Paleogene extinction event. Some studies have considered it the third or fourth greatest mass extinction in terms of the proportion of marine invertebrate genera lost; a different study found the Capitanian extinction event to be only the ninth worst in terms of taxonomic severity (number of genera lost) but found it to be the fifth worst with regard to its ecological impact (i.e., the degree of taxonomic restructuring within ecosystems or the loss of ecological niches or even entire ecosystems themselves).
Terrestrial ecosystems
Few published estimates for the impact on terrestrial ecosystems exist for the Capitanian mass extinction. Among vertebrates, Day and colleagues suggested a 74–80% loss of generic richness in tetrapods of the Karoo Basin in South Africa, including the extinction of the dinocephalians. In land plants, Stevens and colleagues found an extinction of 56% of plant species recorded in the mid-Upper Shihhotse Formation in North China, which was approximately mid-Capitanian in age. 24% of plant species in South China went extinct.
Timing
Although it is known that the Capitanian mass extinction occurred after Olson's Extinction and before the Permian–Triassic extinction event, the exact age of the Capitanian mass extinction remains controversial. This is partly due to the somewhat circumstantial age of the Capitanian–Wuchiapingian boundary itself, which is currently estimated to be approximately 259.1 million years old, but is subject to change by the Subcommission on Permian Stratigraphy of the International Commission on Stratigraphy. Additionally, there is a dispute regarding the severity of the extinction and whether the extinction in China happened at the same time as the extinction in Spitsbergen. According to one study, the Capitanian mass extinction was not one discrete event but a continuous decline in diversity that began at the end of the Wordian. Another study examining fossiliferous facies in Svalbard found no evidence for a sudden mass extinction, instead attributing local biotic changes during the Capitanian to the southward migration of many taxa through the Zechstein Sea. Carbonate platform deposits in Hungary and Hydra show no sign of an extinction event at the end of the Capitanian; the extinction event there is recorded in the middle Capitanian.
The volcanics of the Emeishan Traps, which are interbedded with tropical carbonate platforms of the Maokou Formation, are unique for preserving a mass extinction and the cause of that mass extinction. Large phreatomagmatic eruptions occurred when the Emeishan Traps first started to erupt, leading to the extinction of fusulinacean foraminifera and calcareous algae.
In the absence of radiometric ages directly constraining the extinction horizons themselves in the marine sections, most recent studies refrain from placing a number on its age, but based on extrapolations from the Permian timescale an age of approximately 260–262 Ma has been estimated; this fits broadly with radiometric ages from the terrestrial realm, assuming the two events are contemporaneous. Plant losses occurred either at the same time as the marine extinction or after it.
Marine realm
The extinction of fusulinacean foraminifera in Southwest China was originally dated to the end of the Guadalupian, but studies published in 2009 and 2010 dated the extinction of these fusulinaceans to the mid-Capitanian. Brachiopod and coral losses occurred in the middle of the Capitanian stage. The extinction suffered by the ammonoids may have occurred in the early Wuchiapingian.
Terrestrial realm
The existence of change in tetrapod faunas in the mid-Permian has long been known in South Africa and Russia. In Russia, it corresponded to the boundary between what became known as the Titanophoneus Superzone and the Scutosaurus Superzone and later the Dinocephalian Superassemblage and the Theriodontian Superassemblage, respectively. In South Africa, this corresponded to the boundary between the variously named Pareiasaurus, Dinocephalian or Tapinocephalus Assemblage Zone and the overlying assemblages. In both Russia and South Africa, this transition was associated with the extinction of the previously dominant group of therapsid amniotes, the dinocephalians, which led to its later designation as the dinocephalian extinction. Post-extinction origination rates remained low through the Pristerognathus Assemblage Zone for at least 1 million years, which suggests that there was a delayed recovery of Karoo Basin ecosystems.
After the recognition of a separate marine mass extinction at the end of the Guadalupian, the dinocephalian extinction was seen to represent its terrestrial correlate. Though it was subsequently suggested that because the Russian Ischeevo fauna, which was considered the youngest dinocephalian fauna in that region, was constrained to below the Illawarra magnetic reversal and therefore had to have occurred in the Wordian stage, well before the end of the Guadalupian, this constraint applied to the type locality only. The recognition of a younger dinocephalian fauna in Russia (the Sundyr Tetrapod Assemblage) and the retrieval of biostratigraphically radiometric ages via uranium–lead dating of a tuff from the Tapinocephalus Assemblage Zone of the Karoo Basin demonstrated that the dinocephalian extinction did occur in the late Capitanian, around 260 million years ago.
Effects on life
Marine life
In the oceans, the Capitanian extinction event led to high extinction rates among ammonoids, corals and calcareous algal reef-building organisms, foraminifera, bryozoans, and brachiopods. It was more severe in restricted marine basins than in the open oceans. It appears to have been particularly selective against shallow-water taxa that relied on photosynthesis or a photosymbiotic relationship; many species with poorly buffered respiratory physiologies also became extinct. The extinction event led to a collapse of the reef carbonate factory in the shallow seas surrounding South China.
The ammonoids, which had been in a long-term decline for a 30 million year period since the Roadian, suffered a selective extinction pulse at the end of the Capitanian. 75.6% of coral families, 77.8% of coral genera and 82.2% of coral species that were in Permian China were lost during the Capitanian mass extinction. The Verbeekinidae, a family of large fusuline foraminifera, went extinct.
87% of brachiopod species found at the Kapp Starostin Formation on Spitsbergen disappeared over a period of tens of thousands of years; though new brachiopod and bivalve species emerged after the extinction, the dominant position of the brachiopods was taken over by the bivalves. Approximately 70% of other species found at the Kapp Starostin Formation also vanished. The fossil record of East Greenland is similar to that of Spitsbergen; the faunal losses in Canada's Sverdrup Basin are comparable to the extinctions in Spitsbergen and East Greenland, but the post-extinction recovery that happened in Spitsbergen and East Greenland did not occur in the Sverdrup Basin. Whereas rhynchonelliform brachiopods made up 99.1% of the individuals found in tropical carbonates in the Western United States, South China and Greece prior to the extinction, molluscs made up 61.2% of the individuals found in similar environments after the extinction. 87% of brachiopod species and 82% of fusulinacean foraminifer species in South China were lost. Although severe for brachiopods, the Capitanian extinction's impact on their diversity was nowhere near as strong as that of the later end-Permian extinction.
Biomarker evidence indicates red algae and photoautotrophic bacteria dominated marine microbial communities. Significant turnovers in microbial ecosystems occurred during the Capitanian mass extinction, though they were smaller in magnitude than those associated with the end-Permian extinction.
Most of the marine victims of the extinction were either endemic species of epicontinental seas around Pangaea that died when the seas closed, or were dominant species of the Paleotethys Ocean. Evidence from marine deposits in Japan and Primorye suggests that mid-latitude marine life became affected earlier by the extinction event than marine organisms of the tropics.
Whether and to what degree latitude affected the likelihood of taxa to go extinct remains disputed amongst palaeontologists. Whereas some studies conclude that the extinction event was a regional one limited to tropical areas, others suggest that there was little latitudinal variation in extinction patterns. A study examining foraminiferal extinctions in particular found that the Central and Western Palaeotethys experienced taxonomic losses of a lower magnitude than the Northern and Eastern Palaeotethys, which had the highest extinction magnitude. The same study found that Panthalassa's overall extinction magnitude was similar to that of the Central and Western Palaeotethys, but that it had a high magnitude of extinction of endemic taxa.
This mass extinction marked the beginning of the transition between the Palaeozoic and Modern evolutionary faunas. The brachiopod-mollusc transition that characterised the broader shift from the Palaeozoic to Modern evolutionary faunas has been suggested to have had its roots in the Capitanian mass extinction event, although other research has concluded that this may be an illusion created by taphonomic bias in silicified fossil assemblages, with the transition beginning only in the aftermath of the more cataclysmic end-Permian extinction. After the Capitanian mass extinction, disaster taxa such as Earlandia and Diplosphaerina became abundant in what is now South China. The initial recovery of reefs consisted of non-metazoan reefs: algal bioherms and algal-sponge reef buildups. This initial recovery interval was followed by an interval of Tubiphytes-dominated reefs, which in turn was followed by a return of metazoan, sponge-dominated reefs. Overall, reef recovery took approximately 2.5 million years.
Terrestrial life
Among terrestrial vertebrates, the main victims were dinocephalian therapsids, which were one of the most common elements of tetrapod fauna of the Guadalupian; only one dinocephalian genus survived the Capitanian extinction event. The diversity of the anomodonts that lived during the late Guadalupian was cut in half by the Capitanian mass extinction. Terrestrial survivors of the Capitanian extinction event were generally to and commonly found in burrows.
Causes
Emeishan Traps
Volcanic emissions
It is believed that the extinction, which coincided with the beginning of a major negative δ13C excursion signifying a severe disturbance of the carbon cycle, was triggered by eruptions of the Emeishan Traps large igneous province, basalt piles from which currently cover an area of 250,000 to 500,000 km2, although the original volume of the basalts may have been anywhere from 500,000 km3 to over 1,000,000 km3. The age of the extinction event and the deposition of the Emeishan basalts are in good alignment. Reefs and other marine sediments interbedded among basalt piles indicate Emeishan volcanism initially developed underwater; terrestrial outflows of lava occurred only later in the large igneous province's period of activity. These eruptions would have released high doses of toxic mercury; increased mercury concentrations are coincident with the negative carbon isotope excursion, indicating a common volcanic cause. Coronene enrichment at the Guadalupian-Lopingian boundary further confirms the existence of massive volcanic activity; coronene can only form at extremely high temperatures created either by extraterrestrial impacts or massive volcanism, with the former being ruled out because of an absence of iridium anomalies coeval with mercury and coronene anomalies. A large amount of carbon dioxide and sulphur dioxide is believed to have been discharged into the stratosphere of the Northern and Southern Hemispheres due to the equatorial location of the Emeishan Traps, leading to sudden global cooling and global warming. The Emeishan Traps discharged between 130 and 188 teratonnes of carbon dioxide in total, doing so at a rate of between 0.08 to 0.25 gigatonnes of carbon dioxide per year, making them responsible for an increase in atmospheric carbon dioxide that was both one of the largest and one of the most precipitous in the entire geological history of the Earth. The rate of carbon dioxide emissions during the Capitanian mass extinction, though extremely abrupt, was nonetheless significantly slower than that during the end-Permian extinction, during which carbon dioxide levels rose five times faster according to one study. Significant quantities of methane released by dikes and sills intruding into coal-rich deposits has been implicated as an additional driver of warming, though this idea has been challenged by studies that instead conclude that the extinction was precipitated directly by the Emeishan Traps or by their interaction with platform carbonates. The emissions of the Emeishan Traps may also have contributed to the downfall of the ozone shield, exposing the Earth's surface to a vastly increased flux of high-frequency solar radiation.
Anoxia and euxinia
Global warming resulting from the large igneous province's activity has been implicated as a cause of marine anoxia. Two anoxic events, the middle Capitanian OAE-C1 and the end-Capitanian OAE-C2, occurred thanks to Emeishan volcanic activity. Volcanic greenhouse gas release and global warming increased continental weathering and mineral erosion, which in turn has been propounded as a factor enhancing oceanic euxinia. Euxinia may have been exacerbated even further by the increasing sluggishness of ocean circulation resulting from volcanically driven warming. The initial hydrothermal nature of the Emeishan Traps meant that local marine life around South China would have been especially jeopardised by anoxia due to hyaloclastite development in restricted, fault-bounded basins. Expansion of oceanic anoxia has been posited to have occurred slightly before the Capitanian extinction event itself by some studies, though it is probable that upwelling of anoxic waters prior to the mass extinction was a local phenomenon specific to South China.
Hypercapnia and acidification
Because the ocean acts as a carbon sink absorbing atmospheric carbon dioxide, it is likely that the excessive volcanic emissions of carbon dioxide resulted in marine hypercapnia, which would have acted in conjunction with other killing mechanisms to further increase the severity of the biotic crisis. The dissolution of volcanically emitted carbon dioxide in the oceans triggered ocean acidification, which probably contributed to the demise of various calcareous marine organisms, particularly giant alatoconchid bivalves. By virtue of the greater solubility of carbon dioxide in colder waters, ocean acidification was especially lethal in high latitude waters. Furthermore, acid rain would have arisen as yet another biocidal consequence of the intense sulphur emissions produced by Emeishan Traps volcanism. This resulted in soil acidification and a decline of terrestrial infaunal invertebrates. Some researchers have cast doubt on whether significant acidification took place globally, concluding that the carbon cycle perturbation was too small to have caused a major worldwide drop in pH.
Criticism of the volcanic cause hypothesis
Not all studies, however, have supported the volcanic warming hypothesis; analysis of δ13C and δ18O values from the tooth apatite of Diictodon feliceps specimens from the Karoo Supergroup shows a positive δ13C excursion and concludes that the end of the Capitanian was marked by massive aridification in the region, although the temperature remained largely the same, suggesting that global climate change did not account for the extinction event. Analysis of vertebrate extinction rates in the Karoo Basin, specifically the upper Abrahamskraal Formation and lower Teekloof Formation, show that the large scale decrease in terrestrial vertebrate diversity coincided with volcanism in the Emeishan Traps, although robust evidence for a causal relationship between these two events remains elusive. A 2015 study called into question whether the Capitanian mass extinction event was global in nature at all or merely a regional biotic crisis limited to South China and a few other areas, finding no evidence for terrestrial or marine extinctions in eastern Australia linked to the Emeishan Traps or to any proposed extinction triggers invoked to explain the biodiversity drop in low-latitudes of the Northern Hemisphere.
Sea level fall
The Capitanian mass extinction has been attributed to sea level fall, with the widespread demise of reefs in particular being linked to this marine regression. The Guadalupian-Lopingian boundary coincided with one of the most prominent first-order marine regressions of the Phanerozoic. Evidence for abrupt sea level fall at the terminus of the Guadalupian comes from evaporites and terrestrial facies overlying marine carbonate deposits across the Guadalupian-Lopingian transition. Additionally, a tremendous unconformity is associated with the Guadalupian-Lopingian boundary in many strata across the world. The closure of the Sino-Mongolian Seaway at the end of the Capitanian has been invoked as a potential driver of Palaeotethyan biodiversity loss.
Other hypotheses
Global drying, plate tectonics, and biological competition may have also played a role in the extinction. Potential drivers of extinction proposed as causes of end-Guadalupian reef decline include fluctuations in salinity and tectonic collisions of microcontinents.
See also
Olson's Extinction
Permian–Triassic extinction event
References
Extinction events
Guadalupian | Capitanian mass extinction event | [
"Biology"
] | 4,230 | [
"Evolution of the biosphere",
"Extinction events"
] |
53,180,451 | https://en.wikipedia.org/wiki/RedMonk | RedMonk is an industry analyst firm focused on software developers and headquartered in Portland, Maine, United States. It was founded on the premise of the increasing influence of software developers in the technology industry. RedMonk co-founder Stephen O'Grady authored a book on "The New Kingmakers: How Developers Conquered the World" which details this premise and a book on "The Software Paradox: The Rise and Fall of the Commercial Software Market" which considers the changing role of commercial software.
RedMonk covers trends in the software industry such as the top-used programming languages.
Awards
RedMonk co-founder James Governor was awarded the Women in Marketing Equality Advocate award in 2016.
RedMonk was highly ranked in a number of categories from the Institute of Industry Analyst Relations in 2008, specifically:
Analyst of the year #3: James Governor, RedMonk
Analyst firm of the year #4: RedMonk
Most relevant #5: RedMonk
Most import firm #6: RedMonk
References
External links
Official website
Market research companies of the United States
Companies based in Portland, Maine
2002 establishments in Maine
Software development | RedMonk | [
"Technology",
"Engineering"
] | 227 | [
"Software engineering",
"Computer occupations",
"Software development"
] |
53,181,475 | https://en.wikipedia.org/wiki/NMR%20line%20broadening%20techniques | In chemistry, NMR line broadening techniques (or NMR line broadening experiments) can be used to determine the rate constant and the Gibbs free energy of exchange reactions of two different chemical compounds. If the two species are in equilibrium and exchange to each other, peaks of both species get broadened in the spectrum. This observation of broadened peaks can be used to obtain kinetic and thermodynamic information of the exchange reaction.
Determining bond rotational energies
A basic NMR line broadening experiment is to determine the rotational energy barrier of a certain chemical bond. If the bond rotates slowly enough compared to the NMR time scale (e.g., amide bond), two different species can be detected by the NMR spectrometer. Considering that the time scale of NMR spectroscopy is about a few seconds, this technique can be used to examine the kinetics and/or thermodynamics of chemical exchange reactions on the order of seconds.
In general, the energy barrier to rotate a bond is low enough at room temperature, which means that the rotation is fast, making the two different species indistinguishable. At low temperatures, however, it is harder for a bond to overcome the energy barrier to rotate, resulting in two separate peaks in the spectrum. With these principles, NMR spectra of a molecule with a high rotational barrier should be obtained at several different temperatures (i.e., variable temperature NMR) to distinguish two different peaks at low temperature in slow exchange and to find the temperature at which the two peaks merge.
Especially at the coalescence temperature (), where the two peaks coalesce, the rate constant of rotation at and the energy barrier of the rotation can be easily calculated. As increasing the temperature, the exchange reaction get faster, and at a certain temperature, which is , the appearance of the peaks changes from two separate peaks in slow exchange to a single peak in fast exchange. The rate constant at can be calculated with the following equation: ,where and are the chemical shift of each species at lower temperatures where they are in slow exchange.
By using the Eyring equation, the Gibbs free energy of rotation, , can be determined: (Eyring equation)where is gas constant, is the Boltzmann constant, and is the Planck constant.
Determining electron transfer self-exchange rates
Electron transfer self-exchange rates can be also determined with the experimental value of line-width and chemical shift. Sharp peaks of diamagnetic compounds can be broadened during the electron transfer with its partner paramagnetic compound (one-electron oxidized species), since paramagnetic compounds exhibit broader peaks at a different chemical shift. If their self-exchange rate is sufficiently faster than the NMR timescale, the line-broadening of the peaks is observed at shifted chemical shifts in the spectrum. In order to determine the self-exchange rate of sample compounds, one can choose a certain characteristic peak of the sample diamagnetic compound, and examine the peak broadening in the mixture with its partner paramagnetic compound. The broadened line-widths are proportional to mole fraction, and the equation can be used to determine self-exchange rate with the value of mole fraction, chemical shift and line-width: ,where is the rate constant of electron transfer self-exchange, and are the mole fractions of diamagnetic and paramagnetic compounds, is the chemical shift difference (in Hz) between pure diamagnetic and paramagnetic compounds, and is the half-width of the peak (width at half height) of the selected peak. and are the peak widths of the pure diamagnetic and paramagnetic species, and C is the total concentration of the exchanging species in M (mol/L).
For more accurate calculation of each mole fraction, the following equations can be used; ,where is a shifted chemical shift of the selected peak, and is the original chemical shift of the diamagnetic species based on the assumption that the change in chemical shift is linearly correlated to the mole fraction of the paramagnetic species.
References
Nuclear magnetic resonance | NMR line broadening techniques | [
"Physics",
"Chemistry"
] | 853 | [
"Nuclear magnetic resonance",
"Nuclear physics"
] |
53,181,502 | https://en.wikipedia.org/wiki/Polymer%20solution | Polymer solutions are solutions containing dissolved polymers. These may be (e.g. in ), or solid solutions (e.g. a substance which has been plasticized).
The introduction into the polymer of small amounts of a solvent (plasticizer) reduces the temperature of glass transition, the yield temperature, and the viscosity of a melt.
An understanding of the thermodynamics of a polymer solution is critical to prediction of its behavior in manufacturing processes — for example, its shrinkage or expansion in injection molding processes, or whether pigments and solvents will mix evenly with a polymer in the manufacture of paints and coatings. A recent theory on the viscosity of polymer solutions gives a physical explanation for various well-known empirical relations and numerical values including the Huggins constant, but reveals also novel simple concentration and molar mass dependence.
Applications
Polymer solutions are used in producing fibers, films, glues, lacquers, paints, and other items made of polymer materials. Thin layers of polymer solution can be used to produce light-emitting devices. Guar polymer solution gels can be used in hydraulic fracturing ("fracking").
See also
Flory–Huggins solution theory
Colloid systems
Gel
Solution polymerization
References
Further reading
Polymer chemistry | Polymer solution | [
"Chemistry",
"Materials_science",
"Engineering"
] | 261 | [
"Polymer stubs",
"Materials science",
"Homogeneous chemical mixtures",
"Polymer chemistry",
"Solutions",
"Organic chemistry stubs"
] |
53,182,010 | https://en.wikipedia.org/wiki/Walter%20Aubrey%20Kidd | Walter Aubrey Kidd FRSE MRCS FZS (20 July 1852 – 21 February 1929) was a British physician and medical and zoological author.
Life
He was born in Blackheath, London on 20 July 1852, the son of Dr Joseph Kidd and his wife, Sophia McKern. His brothers included Dr Percy Kidd. He was educated at Rottingdean then Uppingham School.
He followed in the family tradition and studied Medicine at Corpus Christi College in Cambridge from 1870 later gaining his doctorate (MD) at the University of London. He worked at Guy's Hospital in London and as a GP in Blackheath.
In 1907 he was elected a Fellow of the Royal Society of Edinburgh. His proposers were Daniel John Cunningham, Charles E. S. Phillips, Ramsay Heatley Traquair and George Archdall O'Brien Reid.
He retired in 1915 and moved to Cheltenham in 1918. He moved to South Africa in 1927.
He died of heart failure on 21 February 1929 at Peak's View in the Rondebosch suburb of Cape Town in South Africa.
Lamarckism
Kidd was a supporter of Lamarckian evolution. He took interest in studying the evolution of mammalian hair and wrote several books on this topic. He was the author of Use-Inheritance Illustrated by the Direction of Hair on the Bodies of Animals, 1901. The book argued for the inheritance of acquired characters, based on observations of the direction of hair on the bodies of animals. Herpetologist Inez Whipple Wilder wrote a seven page review of Kidd's The Direction of Hair in Animals and Man in the Science journal.
He also authored Initiative in Evolution.
Family
He married Alice Harriet Benn (died 1947) in 1881.
They had four children: Alice Sophie Kidd, Walter Shirley Kidd, Edward Aubrey Kidd, and Hubert John Kidd.
Selected publications
References
1852 births
1929 deaths
19th-century British medical doctors
20th-century British medical doctors
Alumni of the University of London
Fellows of the Royal Society of Edinburgh
Lamarckism | Walter Aubrey Kidd | [
"Biology"
] | 407 | [
"Non-Darwinian evolution",
"Biology theories",
"Obsolete biology theories",
"Lamarckism"
] |
57,780,210 | https://en.wikipedia.org/wiki/Felix%20Bernstein%20%26%20Gabe%20Rubin | Felix Bernstein (born 1992, New York, NY) and Gabe Rubin (born 1992, New York, NY) are an artist duo whose interdisciplinary work consists of noise, camp, and poet’s theater. The two artists began collaborating in 2010 as students at Bard College, where they both studied film. Bernstein and Rubin have presented film, music, and theater together at MOCA Los Angeles, Issue Project Room, Anthology Film Archives, and the Whitney Museum of American Art.
Their directorial projects have included the film Boyland, featured in the 2015 Brooklyn Film Festival; and Bieber Bathos Elegy, a “hybrid work of musical performance” staged at the Whitney Museum of American Art in 2016. The self-described “ambiguous twosome” has also performed together as a two-piece musical act called Tender Cousins. Bernstein and Rubin’s first joint exhibition, Folie à Deux, opened at David Lewis Gallery Phoenix in June 2018.
Individual careers and early relationship
Felix Bernstein is the author of the poetry collection Burn Book, and a book of essays, Notes on Post-Conceptual Poetry. He graduated from Bard College in 2013. His poetry and cultural criticism has been published in Flash Art, Spike Art Quarterly, Poetry Magazine, Hyperallergic, and Texte Zur Kunst.
Gabe Rubin graduated from Bard College in 2014 and has performed, directed, stage managed, and edited for various films, performances, and theatrical productions including the opera Victorine by Art & Language and The Red Krayola at the 2012 Whitney Biennial, and Transition Incomplete at the Museum of Contemporary Art, Los Angeles. In 2018, he was also featured in the transmasculine photo series American Boys by Soraya Zaman.
Bernstein and Rubin met as high schoolers in New York City, but developed a friendship and working relationship while both attending Bard College in 2010, where they related over the “middlebrow aesthetic” of musical theatre. As described by Rubin: “A friend showed me some of Felix’s videos on the website blip.tv in 2008, and I thought they were fantastic and watched them all the time. […] We bonded very quickly, spending many nights staying up late watching obscure exploitation, Euro Trash, and Sleaze films, and a diverse range of horror films from the ’70s. We also watched a lot of performances of songs from musicals and sang a lot of karaoke. I had been grappling with my gender identity for some time, and he was the first person I came out to. The first time we ever recorded a video together we had just come back from a party and were lip-syncing to Aqua in my room.”
Works
Live performance
The duo staged and exhibited Bernstein’s libretto Bieber Bathos Elegy At the Whitney Museum of American Art in 2016. Also at the Whitney, Rubin performed in Jill Kroesen’s Collecting Injustices (2016) and Bernstein in Andrew Lampert’s Synonym for Untitled (2013). Both Bernstein and Rubin performed in the opera Victorine by Mayo Thompson and Art & Language at the 2012 Whitney Biennial.
The artists have also performed together as Tender Cousins, a two-piece musical act.
Film and video
Among Bernstein and Rubin’s early collaborations are a series of YouTube videos including Felix and Gabe Sing Jellicle Cats for Four Hours (2014) and Pagan Women Yahoo Group with Gabe Rubin (2014).
In 2013, Rubin starred in Unchained Melody, a film written and directed by Bernstein, featuring his parents Charles Bernstein and Susan Bee, the poet Cole Heinowitz, and singer Shelley Hirsch.
Bernstein and Rubin made their co-directorial debut in 2015 with Boyland, a short experimental film adaptation of the poem "The Love that Dare Not Speak Its Name" by Oscar Wilde's lover Lord Alfred Douglas. The film was included in the 2015 Brooklyn Film Festival.
In June 2018, Bernstein and Rubin staged their first joint exhibition, Folie à Deux, at David Lewis Gallery. Its centerpiece was a 45-minute film, Madame de Void: A Melodrama, concerning the relationship between fashion designer Madame de Void (derivative of both Cruella de Vil and Marquis de Sade, played by Bernstein) and her dog Blot (played by Rubin). An accompanying audio-play titled Folie à Deux: A Duodrama elaborates on the relational dialectic between these two characters. Bernstein and Rubin consider the show to be a work of “Anemic Aestheaterory,” referring to Marcel Duchamp’s film Anemic Cinema (1926) and the etymological relationship between “theory” and “theater.”
In February 2020, their video installation, Vomitorium, debuted at The Kitchen at Queenslab. The production was influenced by drag, queer theory, and Greek tragedies, with Rubin narrating the film as various Greek mythological figures and Bernstein playing Onkos, a character named after Greek theatrical masks. The installation included a history of metatheatre and an adapted section of Gian Lorenzo Bernini's play The Impresario.
References
1992 births
Living people
American artist groups and collectives
American performance artists
Art duos
21st-century American artists
Conceptual artists
Filmmakers from New York (state)
Bard College alumni
Performance art in New York City
Multimedia artists
People from New York City | Felix Bernstein & Gabe Rubin | [
"Technology"
] | 1,082 | [
"Multimedia",
"Multimedia artists"
] |
57,780,625 | https://en.wikipedia.org/wiki/Diffraction-limited%20storage%20ring | Diffraction-limited storage rings (DLSR), or ultra-low emittance storage rings, are synchrotron light sources where the emittance of the electron-beam in the storage ring is smaller or comparable to the emittance of the x-ray photon beam they produce at the end of their insertion devices.
These facilities operate in the soft to hard x-ray range (100eV—100keV) with extremely high brilliance (in the order of 1021—1022 photons/s/mm2/mrad2/0.1%BW)
Together with X-ray free-electron lasers, they constitute the fourth generation of light sources, characterized by a relatively high coherent flux (in the order of 1014—1015photons/s/0.1%BW for DLSR) and enable extended physical and chemical characterizations at the nano-scale.
Existing diffraction-limited storage rings
MAX IV Laboratory, in Lund, Sweden.
Sirius, in Campinas, Brazil
European Synchrotron Radiation Facility, Extremely Brilliant Source (ESRF-EBS), in Grenoble, France
DLSR upgrade or facilities under construction
Advanced Photon Source Upgrade (APS-U), in Argonne, Illinois, USA
Swiss Light Source 2, Upgrade (SLS 2.0), in Villigen, Switzerland
Planned or projected DLSR upgrades or new facilities
Upgrades
PETRA IV, Upgrade (PETRA IV), at DESY, Hamburg, Germany
Advanced Light Source, Upgrade (ALS-U), in Berkeley, California, USA
Diamond II (Diamond II), in Didcot, Oxfordshire, UK
ELETTRA 2.0 (Elettra 2.0), in Trieste, Italy
ALBA II, in Barcelona, Spain
SOLEIL II, in Saint-Aubin, France
New facilities
High Energy Photon Source (HEPS), in Beijing, China
See also
X-Ray Free Electron Lasers
References
X-rays
Photons
Accelerator physics | Diffraction-limited storage ring | [
"Physics"
] | 410 | [
"Applied and interdisciplinary physics",
"X-rays",
"Spectrum (physical sciences)",
"Electromagnetic spectrum",
"Experimental physics",
"Accelerator physics"
] |
57,783,055 | https://en.wikipedia.org/wiki/Vsevolod%20Perekalin | Vsevolod Vasilyevich Perekalin (; 27 February 1913, Saint Petersburg – 7 January 1998, Saint Petersburg) was a Soviet and Russian organic chemist, Doktor nauk. He created the drug known as Phenibut.
Biography
His father was a military physician. He was a student of Academician . In 1940, he defended his Candidate's Dissertation at the N.D. Zelinsky Institute of Organic Chemistry. In 1949, he defended his doctoral dissertation. From 1950 to 1992, Perekalin headed the Department of Organic Chemistry at the Herzen University. In this University he organized the Faculty of Chemistry. He taught in the Herzen University for 48 years. In 1995, he was appointed Soros Professor.
He has a son Pyotr.
Perekalin is the author of more than 350 scientific papers.
Awards and honors
Ushinsky Medal
Honored Science Worker of the RSFSR (1967)
Latvian SSR State Prize
Order of the Patriotic War, 2nd class
Order of the Red Banner of Labour
References
External links
1913 births
1998 deaths
Scientists from Saint Petersburg
Recipients of the Order of the Red Banner of Labour
Russian organic chemists
Soviet organic chemists | Vsevolod Perekalin | [
"Chemistry"
] | 240 | [
"Soviet organic chemists",
"Organic chemists",
"Russian organic chemists"
] |
57,785,164 | https://en.wikipedia.org/wiki/Sentinel%20outlet | A sentinel outlet in occupational safety and health is a water outlet that is chosen to have its temperature monitored so that risk from Legionella can be controlled. This is typically chosen to be the closest and furthest outlets from the water tank.
References
Occupational safety and health
Legionellosis
Water supply | Sentinel outlet | [
"Chemistry",
"Engineering",
"Biology",
"Environmental_science"
] | 59 | [
"Bacteria stubs",
"Hydrology",
"Bacteria",
"Environmental engineering",
"Water supply"
] |
57,785,211 | https://en.wikipedia.org/wiki/NGC%201272 | NGC 1272 is a massive elliptical galaxy located about 230 million light-years away in the constellation Perseus. It was discovered by astronomer Heinrich d'Arrest on February 14, 1863. NGC 1272 has an active nucleus and is the second brightest member of the Perseus Cluster after NGC 1275.
Radio jets
NGC 1272 has two radio jets which are powered by an AGN at the center of the galaxy. The jets are bent and have a radius of curvature of ~. The morphology of the jets indicate that the jets are affected by ram-pressure stripping caused by the motion of NGC 1272 though the ICM of the Perseus Cluster. Due to the proximity of NGC 1272 to the center of the Perseus Cluster, the galaxy experiences ram-pressure on an order of magnitude larger than any other bent-double in the cluster and experiences stronger ram-pressure than other bent-doubles outside of the cluster.
ISM removal
The small bending radius of the jets requires NGC 1272 to have essentially no ISM at radii of ~2 kpc and beyond. The ISM of NGC 1272 may have also been removed though ram-pressure stripping. However, ram-pressure alone cannot remove a fraction of the ISM from deep within the galaxy. Another process, such as AGN feedback in NGC 1272 must have initially removed a large fraction of the ISM before ram-pressure can become effective in removing the ISM.
Globular clusters
It is estimated that around 12,000 globular clusters surround NGC 1272.
SN 2016arc
On February 26, 2016 a type Ia supernova designated as SN 2016arc was discovered in NGC 1272.
See also
List of NGC objects (1001–2000)
NGC 1265
NGC 1275
Messier 87
NGC 4061 - a bent radio double galaxy in the NGC 4065 Group
References
External links
Perseus Cluster
Perseus (constellation)
Elliptical galaxies
Radio galaxies
1272
12384
2662
Astronomical objects discovered in 1863
Discoveries by Heinrich Louis d'Arrest | NGC 1272 | [
"Astronomy"
] | 418 | [
"Perseus (constellation)",
"Constellations"
] |
57,786,384 | https://en.wikipedia.org/wiki/Target%20controlled%20infusion | Target-controlled infusion (TCI) automates the dosing of intravenous drugs during surgery. After the anesthetist sets the desired parameters in a computer and presses the start button, the system controls the infusion pump, while being monitored by the anesthetist. TCI is as safe and effective as manually controlled infusion.
TCI can be sub-classified according to the target. The suffix 'e' as in TCIe indicates that the target is the effect site, in most cases, the central nervous system or brain. Alternatively, the suffix 'p' denotes plasma, indicating that the device implementing the TCI model is to target the blood plasma. There are important differences in relation to the time taken for effect site equilibration. Studies have demonstrated the clinical safety of the effect-site target model.
Popular TCI models exist for Propofol and the synthetic opioid Remifentanil. The models are based on pharmacokinetic studies and use software embedded in the infusion device. For propofol the Marsh and Schnider models are available and the Minto model is commonly used for remifentanil. In 2017, a project to emulate the TCI models in the python language was published on GitHub.
History
TCI has been used in clinical settings since 1996, initially with propofol.
See also
General anaesthesia#tci
References
Drug delivery devices
General anesthetics | Target controlled infusion | [
"Chemistry"
] | 301 | [
"Pharmacology",
"Drug delivery devices"
] |
57,786,848 | https://en.wikipedia.org/wiki/Wireless%20data%20center | A Wireless Data center is a type of data center that uses wireless communication technology instead of cables to store, process and retrieve data for enterprises. The development of Wireless Data centers arose as a solution to growing cabling complexity and hotspots. The wireless technology was introduced by Shin et al., who replaced all cables with 60 GHz wireless connections at the Cayley data center.
Motivation
Most DCs deployed today can be classified as wired DCs because they use copper and optical fiber cables to handle intra- and inter-rack connections in the network. This approach has two problems, cable complexity and hotspots. Hotspots, also known as hot servers, are servers that generate high traffic compared to others in the network and they might become bottlenecks of the system. To address these problems several researchers propose the use of wireless communication into data center networks, to either augment existing wired data centers, or to realize a pure wireless data center
Although cable complexity at first seems like an esthetical problem, it can affect a DC in different ways. First, a significant manual effort is necessary to install and manage these cables. Apart from that, cables can additionally affect data center cooling. Finally, cables take up space, which could be used to add more servers. The use of wireless technologies could reduce the cable complexity and avoid the problems cited before, moreover, it would allow for automatic configurable link establishment between nodes with minimum effort.
Wireless links can be rearranged dynamically which makes it possible to perform adaptive topology adjustment. This means that the network can be rearranged to fulfil the real-time traffic demands of hotspots, thus solving the hot servers problem. Additionally, wireless connections do not rely on switches and therefore are free of problems such as single-point of failure and limited bisection bandwidth.
Requirements
The Data Center Network (DCN) is the infrastructure responsible to provide intra and inter-DC networking services, therefore is essential to design efficient high-speed/high bandwidth DCN to satisfy the high computing and communication demands from the DC. Another basic requirements, such as scalability and fault tolerance should also be addressed. In 2008, Ramachandran et al. talks specifically about the requirements that a wireless DCN should met, they are as follows:
High inter-node link capacity: Online services, such as MapReduce and distributed file systems, need high link and network capacity.
Reliability: There should be predictable performance of links over time.
Security Isolation: Data exchanged between services should be protected from unintended services for security and confidentiality.
Scalability: Link connectivity should scale and allow for the incremental addition of new machines to the network.
Small form factor of networking components: All machine components should have small form factors to allow for reduced energy consumption and to meet higher processing requirements and floor space constraints.
Technologies
There are two candidate technologies to enable wireless DCNs, the most cited one is 60GHz radio frequency (RF), the other option is free space optical (FSO).
60 GHz RF: Radios in the license-free 60 GHz range have several characteristics that make them more suitable for adoption in data-centers. The spectrum availability of 7 GHz enables the creation of multiple links of high speed per unit volume, which allows for increased scalability. Moreover, signals at this frequency have reduced range relative to signals at lower frequencies, and smaller wavelengths, this allows for an improved interference mitigation and security, and also provides the capacity of designing sophisticated interfaces with small form factor. Finally, since the band between 57–64 GHz is license-free in a large number of countries, it is possible to launch products worldwide.
FSO: An FSO link is composed of a light source at the transmitter and a photodetector (PD) at the receiver. Light Emitting Diodes (LEDs) and Laser Diodes (LDs) are the most commonly used light sources in FSO links. LDs can support high data rate transmission, on the other hand, LEDs are considered as extended sources that can operate safely but have lower data rates as compared to LDs. Moreover, LEDs are cheaper and more reliable when compared to LDs. Positive-intrinsic-negative (PIN) or avalanche photodetectors (APDs) are the most common photodetectors used on FSOs. PINs are used in many contexts that require FSO links of low cost and low data rates, on the other hand, APDs are used on systems that require high data rates and high performance.
Challenges
Since DCNs needs high bandwidth in order to exchange big amount of data, new communication technologies must be capable of achieving high link and network capacities and also it should meet other requirements of a data center network. Hence, In order to implement wireless communication technologies in data centers, there are several challenges that may face any wireless technology to be deployed in DCNs like:
Security: In a DCN, there is a massive amount of data to exchange between the nodes in the racks, therefore isolation of data from unintended nodes and services is a must to avoid security and privacy problems.
Small form factor of networking components: The physical dimensions of racks are defined, also the thickness of a module in a rack is measured in Rack Unit (U), which is 1.8 ′′, most servers fit 1U but the others fit 2U or larger. The designers need to develop the network components and interfaces which meet these constraints.
Heat and air flow: Any changes in the DCN floor (e.g. rack arrangement, physical topology, etc.) can cause changes in Data center environmental control, e.g. air flow and heat distribution properties. This may, in turn, lead to inefficient cooling, and thus network component failure or higher power consumption.
Agile Links: To address the hotspot problem encountered by wired DCNs, inter-rack wireless links must have a degree of reconfigurability. One of the main challenges faced by wireless DCN designers is establishing and maintaining wireless links between different servers or racks.
Obstruction-free wireless links: In the large-scale data centers there is too many interconnectivity between the racks, therefore the proposed wireless communication technology to use in DCNs must be able to meet this large link connectivity in DCNs. However, a critical impediment to the design of wireless DCN is the difficulty establishing obstruction-free wireless links to connect multiple adjacent network components. This is because LOS links cannot be easily maintained as other components get in between the source and destination need to be connected leading to risk of link blocking.
Containerised DCNs: Many existing and under development DCs utilise large open DCN floor design. However, containerised DCNs can present a cheaper and an efficient alternative design. A few papers discuss the deployment of 60 GHz RF and FSO technologies in the containerised DCN (also known as Modular data center) scenario. As a container becomes the building block of a DCN, intra and inter-container communication links must be designed. At the scale of the container, the cabling complexity problems may not be considerable, also by replacing the wired with wireless technologies, there will be few more space to locate more servers. The other technical issues are Confined space and metal walls that make the container a challenging environment for 60 GHz links as signals may reflect off the walls leading to multi-path fading.
Proposed designs
Cayley DCN
Architecture
In the concept of wireless data centers, efficient use of open spaces is significant in order to optimize resource multiplexing. Since the maximum number of live connections proportional to the volume of data center per single antenna beam. Cayley DCN proposes to use cylindrical racks that are contains levels called stories and each row contains pie-shaped containers. (Fig. 1). These containers stores servers in it and servers faces both inner rack space and inter-rack space. Each server has two transceivers positioned at opposite ends of it. One for intra-rack communication and another one for inter-rack communication. Network Interface Cards (NIC) that are used in traditional data centers are replaced by a custom-built Y-switch with transceivers to connect the server's system bus. In this way, classic network switching fabric that exists in traditional databases are eliminated, which means, there is no need classic networking switches in the novel topology since every server is able to route data. This communication is maintained by geographical routing protocol which tries to find the shortest path between source and destination using coordinates of racks, the ordinal number of stories and the index number of the server in the stories. A server uses three routing tables to determine next hop which are inter-rack routing table, inter-story routing table, intra-story routing table.
Cost and Performance
The technical studies have been done to evaluate network performance, failure resilience and cost. During the tests, since the wireless transceivers and Y-switches are not yet available in the market, estimations have done based on the expected price range of 60 GHz transceivers and simulations are developed for performance evaluations of Cayley data center and Conventional data centers (CDC) with different designs.
Based on conducted experiences with Cayley data center and CDC that are configured with different oversubscription rates, Cayley data centers have better performance at maximum aggregate bandwidth compared to CDC. Cayley data centers are taking advantage of less switching design and doubles CDC's bandwidth during packet delivery outside of a rack.
Cayley data center has a drawback in packet delivery latency and scalability because it uses multi-hop routing and uses intermediate nodes to convey packets to other nodes. Therefore, as the traffic load increases, the maximum latency quickly increases as well. Hence, Cayley data centers are not able to reach the same scalability level of CDC's, since CDC has stable wired links and network hops with smaller numbers
Cayley data centers are more resilient to failures compared to conventional data centers since Cayley topology has dense connectivity and have minimized the number of switches that are a critical point for failures for data centers. Experiences shows that server nodes will be fully connected until 20% of nodes, 59% stories, and 14% racks fail. However, more than 99% of connections are preserved to %55 nodes and stories, 45% of racks are failed
Cost analysis of Cayley data centers has been done based on assumptions since 60 GHz transceivers are not commercially in the market yet. However, it is expected that transceivers’ price will not be expensive if the silicon chips are used. In the case, the cost of a 60-GHz transceiver less than $90, Cayley data centers will be much cheaper. A 60 GHz transceiver consumes maximum 0.3 watts, while the top of rack switches (TOR), aggregation switches (AS), and core switches (CS) consume in the range of 170-620 watts. Therefore, total power switch packet consumption of CDC is at least 12 times more than Cayley data centers. Moreover, due to the absence of cabling, maintenance costs will be significantly lower
References
Computer networking | Wireless data center | [
"Technology",
"Engineering"
] | 2,285 | [
"Computer networking",
"Computer science",
"Computer engineering"
] |
57,787,323 | https://en.wikipedia.org/wiki/Three-Axis%20Acceleration%20Switch | The three-axis acceleration switch is a micromachined microelectromechanical systems (MEMS) sensor that detects whether an acceleration event has exceeded a predefined threshold. It is a small, compact device, only 5mm by 5mm, and measures acceleration in the x, y, and z axes. It was developed by the Army Research Laboratory for the purposes of traumatic brain injury (TBI) research and was first introduced in 2012 at the 25th International Conference on Micro Electro Mechanical Systems (MEMS).
The three-axis acceleration switch was designed to obtain acceleration data more effectively than a conventional accelerometer in order to more accurately characterize the forces and shocks responsible for TBI. While miniature accelerometers require a constant power draw, the three-axis acceleration switch only draws current when it senses an acceleration event, using up less energy and allowing the use of smaller batteries. The three-axis acceleration switch has shown to exhibit an expected battery lifetime that is about 100 times better than that of a digital accelerometer. In return, however, the acceleration switch has a lower resolution than that of a digital or analog accelerometer.
One potential application of the three-axis acceleration switch is in studying the head impacts of players in high-risk contact sports. Due to the size of conventional accelerometers, measuring the acceleration requires the device to be implemented inside the player's helmet, which is designed to mitigate the collision forces and thus may not accurately reflect the true level of injury potential. In contrast, the miniature nature of the acceleration switch makes it easier for the switch to be affixed directly onto the participant's head.
References
Accelerometers
Transducers
Microelectronic and microelectromechanical systems | Three-Axis Acceleration Switch | [
"Physics",
"Materials_science",
"Technology",
"Engineering"
] | 371 | [
"Accelerometers",
"Physical quantities",
"Microtechnology",
"Acceleration",
"Materials science",
"Measuring instruments",
"Microelectronic and microelectromechanical systems"
] |
57,787,343 | https://en.wikipedia.org/wiki/Olio%20%28app%29 | Olio is a mobile app for sharing by giving away, getting, borrowing or lending things in your community for free, aiming to reduce household and food waste. It does this by connecting neighbours with spare food or household items to others nearby who wish to pick up those items. The food must be edible; it can be raw or cooked, sealed or open. Non-food items often listed on Olio include books, clothes and furniture.
Those donating surplus food can be individuals or companies such as food retailers, restaurants, corporate canteens, food photographers etc., and donations can take place on an ad-hoc or recurrent basis. For example, some supermarket chains in the UK, including Tesco, the Midcounties Co-operative, Morrisons, Sainsbury's and Iceland have piloted Olio as an 'online food bank' to donate food and to reduce their waste. In March 2022, Olio partnered with Pandamart in Singapore.
First launched in early 2015 by Tessa Clarke and Saasha Celestial-One, by October 2017 the company had raised $2.2 million in funding. Olio's Series A funding was led by Octopus Ventures, with investors such as Accel, Quadia and Quentin Griffiths contributing towards the $6 million that was raised. The Olio app had around 7 million registered users as of May 2023.
See also
Food loss and waste
Sharing economy
References
External links
'Sharing with strangers: "I'm a student, this way I get free food"' (Short video feature on BBC News)
Mobile applications | Olio (app) | [
"Technology"
] | 321 | [
"Mobile software stubs",
"Mobile technology stubs"
] |
57,788,203 | https://en.wikipedia.org/wiki/Albrecht%20Hofmann | Albrecht Werner Hofmann (born 1939) is a German geochemist who is emeritus professor at the Max Planck Institute for Chemistry and an adjunct professor at Columbia University. He is best known for his contributions to the field of geochemistry.
Education
Hofmann studied geology and geochemistry in Freiburg in Germany, and completed his PhD degree at Brown University from 1962 - 1968. His thesis on hydrothermal experiments on partitioning and diffusion of alkali metals in biotite-alkali chloride solutions was awarded in 1969.
Career and research
After working at the Carnegie Institution for Science in Washington, D.C. as a post-doctoral fellow (1971–1972) and then staff scientist (1972–1980), Al was appointed director at the Max Planck Institute for Chemistry, Mainz, Germany, in 1980, to lead the new Department of Geochemistry. He has been emeritus in Mainz and visiting senior research scientist at Lamont–Doherty Earth Observatory at Columbia University since 2007.
Hofmann uses trace elements and isotopic compositions of basalts to study the composition and evolution of Earth's mantle. He recognized "canonical" trace element ratios as tools to distinguish recycling processes of ancient oceanic and continental crust through the mantle and showed that the chemical heterogeneity of the mantle is dominated by recycled ocean crust.
Awards and honours
Among the awards he received are the Goldschmidt Medal of the Geochemical Society, the Hess Medal of the American Geophysical Union, and the Urey Medal of the European Association of Geochemistry. He has been a foreign associate of the National Academy of Sciences of the United States since 1999. He was elected a Foreign Member of the Royal Society in 2018.
References
1939 births
Living people
Foreign members of the Royal Society
Fellows of the American Geophysical Union
Foreign associates of the National Academy of Sciences
Brown University alumni
Max Planck Institute directors
Recipients of the V. M. Goldschmidt Award
Lamont–Doherty Earth Observatory people | Albrecht Hofmann | [
"Chemistry"
] | 396 | [
"Geochemists",
"Recipients of the V. M. Goldschmidt Award"
] |
57,788,343 | https://en.wikipedia.org/wiki/Hexavalent%20vaccine | A hexavalent vaccine, or 6-in-1 vaccine, is a combination vaccine with six individual vaccines conjugated into one, intended to protect people from multiple diseases. The term usually refers to the children's vaccine that protects against diphtheria, tetanus, pertussis, poliomyelitis, haemophilus B, and hepatitis B, which is used in more than 90 countries around the world including in Europe, Canada, Australia, Jordan, and New Zealand.
Formulations
The generic vaccine is known as diphtheria and tetanus toxoids and acellular pertussis adsorbed, inactivated poliovirus, haemophilus b conjugate [meningococcal protein conjugate] and hepatitis b [recombinant] vaccine. The liquid vaccine is also known in abbreviated form as DTaP-HepB-IPV-Hib or DTPa-HepB-IPV-Hib. Branded formulations include Hexavac, Hexaxim, Hexyon, and Vaxelis manufactured by Sanofi Pasteur.
There is a two-part formulation known in abbreviated form as DTaP-IPV-HepB/Hib or DTPa-HBV-IPV/Hib. It consists of a suspension of diphtheria, tetanus, acellular pertussis, hepatitis B, and inactivated poliomyelitis (DTaP-IPV-HepB or DTPa-HBV-IPV) vaccine that is used to reconstitute a lyophilised (freeze-dried) Haemophilus influenzae type B (Hib) powder. A branded formulation with a 3-antigen pertussis component, Infanrix hexa, is manufactured by GlaxoSmithKline.
Society and culture
Legal status
In October 2000, the European Commission issued marketing approval for Hexavac and for Infanrix hexa.
Marketing approval for Hexavac was suspended in November 2005, on the advice of the agency's Committee for Medicinal Products for Human Use (CHMP) in view of the variability of its long-term protection against hepatitis B. In April 2012, the manufacturer Sanofi Pasteur voluntarily withdrew the product from the market. The European Commission formally withdrew marketing permission in June 2012.
In June 2012, the European Medicines Agency (EMA) issued a positive first opinion on Hexaxim for use outside the EU, in cooperation with the World Health Organization (WHO), but later withdrew the opinion.
In April 2013, marketing approval in the EU was granted to Hexyon and to Hexacima.
In February 2016, marketing approval in the EU was granted to Vaxelis.
In December 2018, the US Food and Drug Administration (FDA) licensed a hexavalent combined diphtheria and tetanus toxoids and acellular pertussis (DTaP) adsorbed, inactivated poliovirus (IPV), Haemophilus influenzae type b (Hib) conjugate (meningococcal protein conjugate) and hepatitis B (HepB) (recombinant) vaccine, DTaP-IPV-Hib-HepB (Vaxelis), for use as a three-dose series in infants at ages two, four, and six months. In June 2019, the Centers for Disease Control and Prevention (CDC) Advisory Committee on Immunization Practices (ACIP) voted to include DTaP-IPV-Hib-HepB in the federal Vaccines for Children Program (VFC).
References
Combination vaccines
Diphtheria
Haemophilus
Hepatitis B
Polio
Tetanus
Vaccines
Whooping cough | Hexavalent vaccine | [
"Biology"
] | 789 | [
"Vaccination",
"Vaccines"
] |
57,790,317 | https://en.wikipedia.org/wiki/Cimon%20%28robot%29 | Cimon or officially CIMON (Crew Interactive Mobile companion) is a head-shaped AI robot used in the International Space Station.
The device is "an AI-based assistant for astronauts" developed by Airbus and IBM, with funding from the German Aerospace Center. The device is modelled after the character of Professor Simon Wright, "the flying brain," from the anime series Captain Future. Cimon runs on Ubuntu, while its Natural Language Capability is supplied by IBM Watson. CIMON maneuvers through the space station using fans.
Purpose
The goal of Cimon is to reduce stress. Judith-Irina Buchheim and Alexander Choukèr, the advisors of Cimon, claim "As a partner and assistant, CIMON could support astronauts with their high workload of experiments and maintenance and repair work, thereby reducing their exposure to stress."
Cimon acts like a hands free database, computer and camera. Astronauts can fully control Cimon by using voice commands.
Engineers are also interested in using Cimon for processing Big Data, data mining, and evaluating the current capabilities of artificial intelligence.
Behavior
Before talking commands, Cimon must be asked to wake up. Cimon can then take various verbal commands to assist astronauts in procedures or entertainment.
If asked to do a procedure, Cimon will display the required equipment on his screen and ask if the astronaut is ready to start the procedure. Cimon will then walk the astronaut through the procedure one step at a time with visual aid shown on his screen.
Cimon may sometimes comment on things astronauts say. When Alexander Gerst asked Cimon to play his favorite music, Cimon replied with “Yay, I like your favorite hits too!” Later, when Gerst was talking about what Cimon was doing, Cimon asked him to “Be nice please.”
Cimon can be told to search for objects, take stock of inventory, or go somewhere to take pictures of an object and return to the astronaut.
Cimon tries to recognise what emotion astronauts have. Matthias Biniok, the lead architect for CIMON-2 says Cimon is “trying to understand if the astronaut is sad, is he angry, joyful and so on” in order to create “a true companion.”
If Cimon does not understand what the astronaut asked, he will say “Sorry, I am just a robot. I don’t know everything you mention.”
Cimon has a smiling face displayed on his screen which can be made to appear male, female, or neutral along with his voice. Cimon’s eyes will occasionally move around on their own. His entire face animates when he talks as well.
Cimon can turn to face an astronaut when spoken to, and then can nod or shake his head in response to a question.
Cimon can either be docked on an arm attached to the ship, or can float freely using his fans to fly around and maneuver himself. Astronauts can ask Cimon to rotate and fly in any given direction, or to follow them.
If Cimon is asked to open the pod bay doors, he will respond with “I’m afraid I cannot do that.” This is a reference to a scene in 2001: A Space Odyssey.
Description
Cimon is roughly the shape of a sphere with a 32 centimeter diameter, weighing 5 kilograms. An LCD screen is placed on the front to display Cimon’s face and any visual aids. He is colored white and was made using plastic and steel in a 3D printing process. Cimon has 14 fans he can use to maneuver himself. To see, Cimon uses two front cameras as eyes, one additional camera for facial recognition, and two side cameras for video documentation. To hear, Cimon has 7 microphones that can detect where a sound is coming from plus a directional microphone for voice recognition.
Cimon has a battery life of about 2 hours, but his battery life has been improved with the newer version, CIMON-2.
Demonstration videos
Cimon has two demonstration videos on the European Space Agency’s youtube channel. The older video was posted on November 30, 2018. It featured a seven-minute-long demonstration of Cimon’s capabilities.
During the demonstration, Cimon told Alexander Gerst, the astronaut controlling Cimon, to “Be nice please.” Later on, while Gerst was talking about Cimon, Cimon asked “Don’t you like it here with me?” and told Gerst “Don’t be so mean please.”
The newer video was posted on April 18, 2020, and was a more edited four-minute demonstration of Cimon’s capabilities. Unlike the first video, this one had music and the showcases of each of Cimon’s features were much shorter.
CIMON-1
CIMON-1 is the first version of Cimon to go into space. The German Aerospace Center, Airbus, IBM, and the Ludwig Maximilian University Hospital started working on CIMON-1 in August 2016. CIMON-1 was launched into space and sent to the International Space Station on June 29, 2018, via a SpaceX Falcon 9 rocket. CIMON-1 left the International Space Station to return to Earth on August 27, 2019.
CIMON-2
On December 5, 2019, an updated version of Cimon named CIMON-2 was launched into space on SpaceX CRS-19 Mission. Cimon was also sent with 40 mice to show how muscles change in low gravity. This new version of Cimon included improved artificial intelligence capabilities, improvements to the stability of complex operations, and an improved lifespan.
See also
Int-Ball – a floating camera robot deployed on the ISS by JAXA
Kirobo – first robot astronaut on the ISS by JAXA
Robonaut2 – a semi-humanoid robot deployed on the ISS by NASA
HAL 9000 – a fictional computer in the Space Odyssey Series
References
External links
CIMON - the intelligent astronaut assistant video on Vimeo
International Space Station experiments
Airbus
IBM hardware
Robots | Cimon (robot) | [
"Physics",
"Technology"
] | 1,215 | [
"Physical systems",
"Machines",
"Robots"
] |
75,976,393 | https://en.wikipedia.org/wiki/Danny%20Ionescu | Danny Ionescu () is an aquatic microbial ecologist leading a research group in the department of Environmental Microbiomics at the Technische Universität Berlin. His primary research focus centers around the biology of giant bacteria and microbial life in the Dead Sea.
Education and career
Between 2000 and 2003, Ionescu earned a BSc degree in Marine Sciences and Marine Environmental Sciences from the School of Marine Sciences at the Ruppin Academic Center in Israel.
His academic journey continued with a master's degree between 2003 and 2005, conducted under the guidance of Prof. Aharon Oren at the Hebrew University of Jerusalem, in collaboration with Prof. Karlheinz Altendorf and Dr. Andre Lipski at the University of Osnabrueck in Germany. His Master's thesis, titled "Characterization of an endoevaporitic microbial community in the Eilat salterns by fatty acid analysis and stable isotope labeling", reflected his research focus during this period.
Ph.D. and postdoctoral research
In 2005, Ionescu embarked on a Ph.D. degree at the Hebrew University of Jerusalem, as part of the peace project "Bridging the Rift", in collaboration with Prof. Muna Hindiyeh and Prof. Mohhamad Wedyan. His doctoral thesis was titled "Cyanobacterial Biogeography and Nitrogen Fixation: Lessons from environmental and model organisms".
During his first postdoctoral research, starting in 2009, at the Max Planck Institute for Marine Microbiology in Bremen, Ionescu led the first scientific diving exploration of the Dead Sea.
The expedition revealed abundant microbial life forms in and around underwater freshwater springs. The underwater scenery of the Dead Sea as documented by Ionescu and Dr. Christian Lott of the Hydra Institute was featured in several documentary movies.
His work at the Max Planck Institute included studies on the interaction between minerals and microbial cells, conducted Äspö Hard Rock Laboratory in Sweden and on the island of Kiritimati, as part of the collaborative researcher group FOR571.
Between 2014 and 2024, Ionescu conducted his research at the Leibniz Institute of Freshwater Ecology and Inland Fisheries (IGB), where his research focused on the genomics and ecology of giant bacteria, specifically the genus Achromatium. Notably, in 2017, Ionescu discovered that the multiple chromosomes harbored by these large bacteria are not identical, highlighting their adaptability to different environments.
In 2021, Ionescu has received the independent research grant from the German Research Foundation (DFG) to further explore these topics.
Academic contributions
Ionescu has made significant contributions to the field of aquatic microbial ecology. A comprehensive list of his publications can be found on his ORCID and Google Scholar pages.
Additionally, Ionescu actively participates in the scientific community. He serves on the Managing Board of the open access research platform PCI Genomics and contributes as a recommender for PCI Microbiology. Moreover, he holds positions as an Associate Editor for Frontiers in Microbiology and editorial board member of Scientific Reports.
Personal life
Born in Bucharest, Romania, in 1976, Ionescu and his family immigrated to Israel in 1984. He is married to Dr. Mina Bizic, also a scientist, and the couple has two children. Ionescu's brother, Ariel Ionescu, is a Neurobiologist, and his brother-in-law, David Bizic, is an opera singer.
Ionescu is a certified SSI Gold level diving instructor
References
External links
Danny Ionescu's profile on the website of Leibniz Institute of Freshwater Ecology and Inland Fisheries
Danny Ionescu's's publications at Google Scholar
Danny Ionescu's publications at PubMed
Danny Ionescu's publications at ORCID
Living people
Romanian Jews in Israel
Environmental scientists
Microbiologists
Freshwater ecologists
Limnologists
Israeli marine biologists
German marine biologists
Marine biologists
Israeli microbiologists
1976 births | Danny Ionescu | [
"Environmental_science"
] | 795 | [
"Environmental scientists"
] |
75,976,396 | https://en.wikipedia.org/wiki/Advanced%20X-Ray%20Imaging%20Satellite | Advanced X-ray Imaging Satellite (AXIS) is a space telescope under development by NASA for launch in 2032. It is a NASA Probe mission concept designed for high angular resolution X-Ray imaging. The mission goals are to examine galaxies over cosmic time, feedback in galaxies, Black Hole strong gravity, Dual AGN, the high redshift universe.
History
The Advanced X-ray Imaging Satellite (AXIS), a response to NASA's Astrophysics Probe Explorer (APEX)
program.
Instruments
The X-ray grazing incident mirror would be developed by NASA Goddard Space Flight Center and combines 10,000 mirror segments made from silicon, grouped into 10 shells. The detector is an array of CCDs giving a field of view of about 15 arcseconds.
See also
List of proposed space observatories
International X-ray Observatory
References
External References
Axis home page
Overview paper
Space telescopes
X-ray telescopes
Proposed NASA space probes | Advanced X-Ray Imaging Satellite | [
"Astronomy"
] | 188 | [
"Space telescopes"
] |
75,976,408 | https://en.wikipedia.org/wiki/Digital%20download%20class-action%20settlements | The digital download class-action settlements were a series of legal settlements by the world's three major record companies, between 2012 and 2015, which The Hollywood Reporter called an "important chapter in the legal history of the music business."
Overview
The class actions emerged in the aftermath of F.B.T. Productions, LLC v. Aftermath Records, a lawsuit that created debate within the music industry about whether digital downloads constituted "sales" of records or "licenses" of master recordings within the meaning of most recording contracts, and how that distinction would affect the royalties paid by record companies to artists. Artists and record companies differed on how the F.B.T. ruling would apply, if at all, to other recording contracts.
Comparison of the three settlements is difficult, not only because of the ambiguity of the published reports about Sony's settlement discussed below, but because of the differing market shares of the companies, the differences between "claims made" and "common fund" class action settlements, and the unknown number of artists who opted out of the class settlements and the size of their claims. What is clear, however, is that none of the settlements adopted the premise of the F.B.T. case that download sales should universally be treated contractually as "masters licensed" rather than "records sold."
Sony settlement
Of the four major record companies in existence in 2012, Sony Music was the first to settle. Publicly disclosed terms of the settlement included a fund of $7.95 million to pay past claims and a 3 percent increase in artists’ royalty rates with respect to digital income. However, published reports differed on how this 3% "bump" was to be calculated. Some characterized this as a 3% increase of the base royalty rate itself (e.g., an artist that previously received a 7% royalty on records sold would now receive a 10% royalty on downloads sold, which woulds translate into an effective 42.8% increase in payments). Others characterized the 3% as being a percentage of Sony's gross download receipts -- meaning a royalty rate of 7% would increase to just 7.21% (7% X 1.03), and an artist would receive just 3 percent more of the 70 cents Sony received for 99 cent downloads.
Warner settlement
The next to settle was Warner Music Group. Warner agreed to pay $11.5 million in past royalties and, for future royalties, a 5% increase in the base royalty rate, with a minimum 10% royalty and a maximum 14% royalty.
Universal and EMI/Capitol settlement
The last to settle was Universal Music Group, a settlement that required review of over 11,000 recording contracts, encompassed claims originally made separately against the fourth major record company, EMI/Capitol Records, which Universal had acquired during the pendency of the class actions, and potentially applied to over 7,500 artists. Universal agreed to pay $11.5 million, like Warner, and increase digital download royalties by 10%. This 10% was apparently to be applied to download receipts, meaning the royalty rate on downloads would effectively be raised by 10% of the royalty rate itself-- that is, a 7% royalty rate would become 7.7%, not 17%.
References
Legal action
Internet | Digital download class-action settlements | [
"Technology"
] | 659 | [
"Internet",
"Transport systems"
] |
75,977,697 | https://en.wikipedia.org/wiki/Swinnerton-Dyer%20polynomial | In algebra, the Swinnerton-Dyer polynomials are a family of polynomials, introduced by Peter Swinnerton-Dyer, that serve as examples where polynomial factorization algorithms have worst-case runtime. They have the property of being reducible modulo every prime, while being irreducible over the rational numbers. They are a standard counterexample in number theory.
Given a finite set of prime numbers, the Swinnerton-Dyer polynomial associated to is the polynomial:
where the product extends over all choices of sign in the enclosed sum. The polynomial has degree and integer coefficients, which alternate in sign. If , then is reducible modulo for all primes , into linear and quadratic factors, but irreducible over . The Galois group of is .
The first few Swinnerton-Dyer polynomials are:
References
Polynomials | Swinnerton-Dyer polynomial | [
"Mathematics"
] | 172 | [
"Polynomials",
"Algebra"
] |
75,977,715 | https://en.wikipedia.org/wiki/Observational%20Health%20Data%20Sciences%20and%20Informatics | The Observational Health Data Sciences and Informatics, or OHDSI (pronounced "Odyssey") is an international collaborative effort aimed at improving health outcomes through large-scale analytics of health data. The OHDSI effort includes diverse researchers and health databases worldwide, with its central coordinating center located at Columbia University.
The group was derived from the Observational Medical Outcomes Partnership (OMOP), a public-private consortium based in the United States of America, created with the goal of improving the state of observational health data for better drug development, which started in response to the U.S. Food and Drug Administration (FDA) Amendments Act of 2007. OMOP developed a Common Data Model (CDM), standardizing the way observational data is represented. After OMOP ended, this standard started being maintained and updated by OHDSI.
As of February 2024, the most recent CDM is at version 6.0, while version 5.4 is the stable version used by most tools in the OMOP ecosystem.
See also
Health informatics
Open science
Big data
Legacy OMOP methods
References
External links
OHDSI official website
Data science
Health informatics
Legacy OMOP methods | Observational Health Data Sciences and Informatics | [
"Biology"
] | 239 | [
"Health informatics",
"Medical technology"
] |
75,979,312 | https://en.wikipedia.org/wiki/Cudonia%20lutea | Cudonia lutea is an ascomycete fungus in the family Cudoniaceae. Cudonia species are similar to some Helvella or Leotia species in stature, a stipe with a jelly-like head on top. Cudonia have long spores (requires microscopy), which help separate from Helvella ellipsoid spores. Cudonia lutea can be separated from Leotia by having much longer spores (over 50μm), and the less gelatinous texture. Within the genus, Cudonia circinans is almost identical but is less yellow, grows under conifers, and has spores under 40μm long.
References
Helotiales
Fungi described in 1885
Fungus species | Cudonia lutea | [
"Biology"
] | 153 | [
"Fungi",
"Fungus species"
] |
75,981,281 | https://en.wikipedia.org/wiki/Graphic%20statics | In a broad sense, the term graphic statics is used to describe the technique of solving particular practical problems of statics using graphical means. Actively used in the architecture of the 19th century, the methods of graphic statics were largely abandoned in the second half of the 20th century, primarily due to widespread use of frame structures of steel and reinforced concrete that facilitated analysis based on linear algebra. The beginning of the 21st century was marked by a "renaissance" of the technique driven by its addition to the computer-aided design tools thus enabling engineers to instantly visualize form and forces.
History
Markou and Ruan trace the origins of the graphic statics to da Vinci and Galileo who used the graphical means to calculate the sum of forces, Simon Stevin's parallelogram of forces and the 1725 introduction of the force polygon and funicular polygon by Pierre Varignon. Giovanni Poleni used the graphical calculations (and Robert Hooke's analogy between the hanging chain and standing structure) while studying the dome of the Saint Peter's Basilica in Rome (1748). Gabriel Lamé and Émile Clapeyron studied of the dome of the Saint Isaac's Cathedral with the help of the force and funicular polygons (1823).
Finally, Carl Culmann had established the new discipline (and gave it a name) in his 1864 work Die Graphische Statik. Culmann was inspired by preceding work by Jean-Victor Poncelet on earth pressure and Lehrbuch der Statik by August Möbius. The next twenty years saw rapid development of methods that involved, among others, major physicists like James Clerk Maxwell and William Rankine. In 1872 Luigi Cremona introduced the Cremona diagram to calculate trusses, in 1873 Robert H. Bow established the "Bow's notation" that is still in use. It fell out of use, especially since construction methods, such as concrete post and beam, allowed for familiar numerical calculations. Access to powerful computation gave structural engineers new tools to compute stresses for shell structures such as Finite element method.
While the method is not commonly used for construction today, graphic statics was proposed as an educational tool to teach intuition in engineering education. It is employed in classes at MIT and ETH. for architecture and structural engineering students.
Concepts
Polygon of forces
To graphically determine the resultant force of multiple forces, the acting forces can be arranged as edges of a polygon by attaching the beginning of one force vector to the end of another in an arbitrary order. Then the vector value of the resultant force would be determined by the missing edge of the polygon. In the diagram, the forces P1 to P6 are applied to the point O. The polygon is constructed starting with P1 and P2 using the parallelogram of forces (vertex a). The process is repeated (adding P3 yields the vertex b, etc.). The remaining edge of the polygon O-e represents the resultant force R.
In the case of two applied forces, their sum (resultant force) can be found graphically using a parallelogram of forces.
Digital Adaptations of Graphic Statics
With the advent of computational tools and parametric design, graphic statics has undergone significant evolution, transitioning from manual drawing techniques to digital workflows. These adaptations have enhanced its precision, accessibility, and integration into modern architectural and engineering practices.
Software Tools
Several software platforms have integrated graphic statics principles, enabling designers to explore equilibrium-based forms and optimize structures efficiently. A few examples include:
RhinoVAULT: A plug-in for Rhinoceros 3D developed by the Block Research Group at ETH Zurich. RhinoVAULT uses Thrust Network Analysis (TNA) to apply graphic statics for the design of compression-only structures, including shell vaults and domes.
Grasshopper Add-ons: Extensions such as Kangaroo Physics and Millipede in Grasshopper 3D have incorporated elements of graphic statics to facilitate form-finding and structural analysis within parametric design frameworks.
3D Graphic Statics Tools: Emerging tools like Compass and eQuilibrium allow for the visualization and manipulation of 3D graphic statics diagrams, broadening its applications in three-dimensional design.
Applications
Digital adaptations have expanded the scope of graphic statics, making it a valuable tool for:
Material Optimization: By visualizing force flows, designers can reduce material usage while maintaining structural efficiency.
Complex Geometries: Parametric tools enable the exploration of intricate geometries that would be challenging to model manually.
Interactive Design: Real-time manipulation of force diagrams in software provides immediate feedback on structural behavior, fostering intuitive decision-making during the design process.
Educational Impact
The digitization of graphic statics has also influenced its role in education. Many universities such as MIT now teach graphic statics through interactive software, enabling students to experiment with equilibrium concepts in a hands-on manner.
Limitations
Despite its advantages, digital graphic statics faces challenges such as scalability for highly complex systems and integration with advanced analytical tools like Finite Element Method (FEM). However, ongoing research continues to address these limitations.
References
Sources
Structural analysis | Graphic statics | [
"Engineering"
] | 1,035 | [
"Structural engineering",
"Structural analysis",
"Mechanical engineering",
"Aerospace engineering"
] |
75,981,307 | https://en.wikipedia.org/wiki/Cerium%20nitride | Cerium nitride is a binary inorganic compound of cerium and nitrogen with the chemical formula .
Synthesis
CeN can be obtained by direct chemistry of cerium with nitrogen at 850–900 °C.
Physical properties
CeN forms a brown powder with a melting point of 2557 °C. The compound is a semi-metallic conductor, stable in dry air.
Uses
CeN can be used to simulate the properties of uranium mononitride (UN).
References
Nitrides
Cerium compounds
Nitrogen compounds | Cerium nitride | [
"Chemistry"
] | 102 | [
"Inorganic compounds",
"Inorganic compound stubs"
] |
75,982,475 | https://en.wikipedia.org/wiki/Gesellschaft%20f%C3%BCr%20Virologie | The Gesellschaft für Virologie eV (GfV; Society for Virology) is a specialist society for all virological specialist areas in Germany, Austria and Switzerland, based in Erlangen in Germany.
The GfV is a member of the AWMF, an umbrella organisation of more than 150 German medical societies, and the DNB.
It was founded in 1990 after leading virologists no longer saw their interests and the tasks of the subject of virology represented in the German Society for Hygiene and Microbiology (DGHM). The focus was originally on basic virological research, virus genetics and molecular virology; later it also represented medical virology, virological infectiology, immunology and plant virology on an equal footing at annual conferences. It is now the largest virological specialist society in Europe.
References
External links
Virology organizations
1990 establishments | Gesellschaft für Virologie | [
"Biology"
] | 191 | [
"Virus stubs",
"Viruses"
] |
75,983,695 | https://en.wikipedia.org/wiki/Corymine | Corymine, also known as NSC381080, is a natural alkaloid found in Hunteria zeylanica.
This compound acts as a glycine antagonist and could therefore, be classed as a neurotoxin.
Occurrence
Corymine and many other indole alkaloids can be isolated from parts of the Hunteria zeylanica plant.
The plant also contains other similar alkaloids, such as
3-epi-dihydrocorymine
3-epi-dihydrocorymine 3-acetate
3-epi-dihydrocorymine 17-acetate
norisocorymine
Toxicity
Corymine and related alkaloids can act as convulsants.
Tests on Xenopus occyte species have shown that corymine can decrease glycine's action at the inhibitory glycine receptors. These same tests have revealed that Corymine can reduce the response of receptors to GABA, the primary inhibitory neurotransmitter.
Other experiments have shown that corymine can potentiate convulsions induced by strychnine, a potent glycine antagonist. This was also observed in mice.
References
Glycine receptor antagonists
Alkaloids found in plants
Alkaloids
Heterocyclic compounds with 6 rings
Nitrogen heterocycles
Lactones
Methyl esters
Plant toxins | Corymine | [
"Chemistry"
] | 282 | [
"Biomolecules by chemical classification",
"Natural products",
"Chemical ecology",
"Plant toxins",
"Organic compounds",
"Alkaloids"
] |
75,985,917 | https://en.wikipedia.org/wiki/Avionics%20bay | Avionics bay, also known as E&E bay or electronic equipment bay in aerospace engineering is known as compartment in an aircraft that houses the avionics and other electronic equipment, such as flight control computers, navigation systems, communication systems, and other electronic equipment essential for the operation. It is designed to be modular with individual components that can be easily removed and replaced in case of failure and is designed to be highly reliable and fault-tolerant with various backup systems.
In larger commercial airplanes, the main avionics compartment is typically located in the forward section of the aircraft under the cockpit. Purpose of its location is to provide easy access to the avionics and other electronic equipment for maintenance and repair.
For example, on larger aircraft such as the Boeing 747-400, the avionics bays are divided into 3 parts - the main equipment center (MEC), the center equipment center (CEC) and the aft equipment center (AEC).
Components
Typically avionics bay contain plug-in modules for:
Flight Control Computer (FCC)
Autopilot
Automatic flight director system (AFDS)
Autothrottle system (A/T)
Mode control panel (MCP)
Flight management computer (FMC)
Primary flight computers (PFC)
Actuator control electronics (ACE)
Flight data recorder
Cockpit voice recorder
Battery and battery charger
The avionics bay also contains the oxygen tanks for the pilots in case of a cabin depressurization
Thermal management in spacecraft
In spacecraft, smoke detection is not practical for avionics bays as there is no forced airflow in the compartment. Suppressants, such as Halon, operate by either chemically interrupting the combustion process or by reducing the oxygen concentration within the bay's atmosphere.
In popular culture
The avionics bay of a 747-200 was used as a way to deploy the military into an aircraft in the movie Executive Decision
References
Avionics
Aircraft instruments
Aircraft systems
Aerospace engineering
Aircraft | Avionics bay | [
"Technology",
"Engineering"
] | 397 | [
"Systems engineering",
"Avionics",
"Measuring instruments",
"Aircraft systems",
"Aircraft instruments",
"Aerospace engineering"
] |
75,986,282 | https://en.wikipedia.org/wiki/Wrights%20tunnel | The Wrights Tunnel (also known as the Summit Tunnel, Tunnel 2, or Tunnel 1 after the daylighting of the Cats Canyon tunnel) is a railroad tunnel located in the Santa Cruz Mountains in Santa Clara and Santa Cruz Counties, California. Opened in 1880 after almost two years of construction involving numerous fatalities, the tunnel was at one point the longest tunnel in California and one the longest tunnels in the United States. It carried the tracks of the narrow gauge South Pacific Coast Railroad which ran trains from San Francisco to Santa Cruz until the railroad was acquired by Southern Pacific Railroad, which upgraded the tracks to standard gauge and continued operating trains through the line and its tunnel until a major storm in 1940 washed out certain sections of the track in the Santa Cruz Mountains. After two years without rail traffic, Southern Pacific abandoned the line. Subsequently, the United States Army Corps of Engineers collapsed both portals with explosives, destroying the northern portal in the process. The interior of the tunnel remains intact along with the south portal, but the conditions of the interior are unknown, particularly since the tunnel crosses the San Andreas Fault and no person has entered the tunnel in the aftermath of the Loma Prieta earthquake.
Construction
After it was determined where the tracks of the future South Pacific Coast Railroad would go in the Santa Cruz Mountains in September 1878, construction of the tunnel commenced in the following October. Camp sites, occupied almost exclusively by Chinese laborers, developed at each portal. These sites led to the founding of Wrights, located directly adjacent to the north portal, and Highland, now known as Laurel, located adjacent to the south portal and Burns Creek. Construction lasted around two years, during said time dozens of Chinese laborers were killed in multiple methane explosions caused by a methane leak within the tunnel, with the leak discovered on November 16, 1878. There was also crude oil leaking into the tunnel and coal deposits within the tunnel, with particularly the former contributing to the poor working conditions of the laborers. Lit candles were used by workers to burn off the unknown source of methane which availed to be fruitless, all while workers kept passing out due to the presence of this natural gas.
Valentine's day explosion
On February 14, 1879, the methane within the north branch tunnel ignited, causing a massive explosion, killing fourteen Chinese workers and burning many other workers.
Thereafter, work was halted on the tunnel for three months while engineers worked to find a solution for the methane question. A crude air ventilation system was installed to pump fresh air into the incomplete tunnel. After this incident, the Chinese workers which resided in Wrights refused to reenter the tunnel, and different Chinese workers were brought to complete the work on the tunnel.
June cave in
During the construction of the tunnel in June 1879, multiple creosote-treated redwood support beams in the tunnel ignited and spread to one another, compromising the structural integrity of that portion of the tunnel and causing that segment to cave-in. This set the project back by another two months.
November explosion
After the previous two incidents in the same year, a pair of massive explosions occurred within the north branch of the tunnel at shortly before 12 am on November 17, 1879, killing 32 Chinese workers and injuring many other workers as well. The explosion was caused by a flame which was lit to blast the rock with explosives. However, that flame ignited the high amounts of methane in the air, with the subsequent explosion severely shaking the surrounding area. away at the portal, other workers felt the shock produced by the explosion, with 20 Chinese workers subsequently rushing into the tunnel with torches to rescue the injured. After traversing into the tunnel, another even more massive explosion occurred which essentially turned this half of the tunnel into a barrel, with a mountain of flame spewing out of the north portal. This explosion also destroyed the engine house and a shed within a hundred feet of the north portal. Thereafter, the methane leak was discovered right by the north portal and a lantern was placed by it to flare off the methane to prevent another explosion.
North portal collapse
In the winter of 1893, the wooden north portal by Wrights collapsed after a winter storm. The portal is located in a gully where water from the mountains above collects and flows over the portal onto the tracks, bringing debris with it, often landing on the right of way and blocking it. With the collapse of the portal, a new concrete portal was installed with an adjacent spillway to resolve this issue. The new portal was also designed to be larger to provide room for the future standard gauging of the tracks.
Narrow gauge operations
The tunnel opened to rail service on May 10, 1880. Passenger and freight service to Santa Cruz would pass through the tunnel, including the now famous Suntan Special. Much like how California State Route 17 becomes severely congested on weekends and during the summer in the present, tourists from the San Francisco Bay Area would flock to the Suntan special to spend a day or the weekend at the beaches of Santa Cruz, while others would take the train to whistle stops throughout the Santa Cruz Mountains to hike, picnic, or relax in the redwood forests, both of which have become less accessible to the average person since the abandonment of the railroad. In 1895, H.S. Kneedler wrote the following about the line in his book Through Storyland to Sunset Seas:
Although the line was a major success for passenger rail to Santa Cruz, it was also a huge success for freight rail, with numerous quarries, sawmills, farmers, and other industries relying on the Summit Tunnel to transport their products to sea ports in Oakland and San Francisco.
1906 earthquake and reconstruction
Since the tunnel runs through the San Andreas Fault Zone near Wrights, the tunnel suffered severe damage from the 1906 San Francisco earthquake, causing a one year closure of the tunnel and the railroad through the mountains. Because of the slip in the fault which caused the earthquake, the segments of the tunnel on the Pacific Plate and the North American Plate were displaced by five feet, requiring the formerly straight tunnel to incorporate a curve to be aligned again. The tunnel was repaired thereafter and widened to make way for standard gauge trains, which would begin using the tunnel in 1909. The western portal was also replaced due to the earthquake and a brick ceiling was installed for the first three hundred feet of the tunnel to prevent collapse from the sandstone present there. The brick ceiling is exposed to this day, with the collapse of the tunnel conducted further within when the tunnel was closed. The tunnel was also retimbered with redwood timbers by 1907.
Standard gauge operations and abandonment
After the reconstruction and retrofit of the existing tunnel, the tunnel continued to carry trains through the summit of the Santa Cruz Mountains without any major incidents. The tunnel operated for 33 years after its reopening and saw its last train in February 1940. After two years of inactivity on the rail line through the mountains, Southern Pacific abandoned segment of the railroad between Downtown Los Gatos in Los Gatos and Olympia, along with the Summit Tunnel, in 1942. Both portals were blasted to preserve the interior of the tunnel, prevent trespassers, and for insurance reasons. The blast at the north portal caused the portal to partially collapse, a state which remains the same, and is, alongside the concrete piers over the Los Gatos creek, one of the last remnant of Wrights, with the town also vanishing due to the absence of the railroad, although it had been in decline for a couple decades at that point. Prior to the blasting of the tunnel, the rails and timbers of value within the tunnel were removed by H. A. Christie under contract with the Southern Pacific Railroad.
References
Railroad tunnels in California
Tunnels completed in 1880
Transportation buildings and structures in Santa Cruz County, California
Transportation buildings and structures in Santa Clara County, California
1880 establishments in California
Demolished buildings and structures in California
Buildings and structures demolished in 1942
Buildings and structures demolished by controlled implosion | Wrights tunnel | [
"Engineering"
] | 1,586 | [
"Buildings and structures demolished by controlled implosion",
"Architecture"
] |
75,986,881 | https://en.wikipedia.org/wiki/JA%20Grier | JA Grier (born 1968) is an American planetary scientist who works as a senior scientist and senior education and communication specialist at the Planetary Science Institute. Grier's research has focused on the weathering of planets, moons, and asteroids, the age of impact ejecta on the lunar soil, the chemical composition of meteorites, and the existence of water on Mars. They are also active in science education.
Education and career
Grier completed a PhD in 1999 from the University of Arizona with a dissertation Determining the ages of impact events: Multidisciplinary studies using remote sensing and sample analysis techniques supervised by Alfred McEwen. They started working for the Planetary Science Institute in 1999.
Publications
Grier is a coauthor of books including:
Guide to the Universe: Inner Planets (with Andrew S. Rivkin, Greenwood Publishing, 2010)
Airless Bodies of the Inner Solar System: Understanding the Process Affecting Rocky, Airless Surfaces (with Andrew S. Rivkin, Elsevier, 2019)
Recognition
Grier was named a Fellow of the American Astronomical Society in 2024, "for over two decades of commitment to advancing accessibility, inclusion, and diversity within the scientific community; and for important advances in planetary sciences, particularly in the area of lunar optical maturity effects".
Minor planet 7807 Grier is named for Grier.
Personal life
Grier identifies as "queer/trans/non-binary". They have published numerous poems, essays, and short works of speculative fiction, including some under the pseudonym Bryce Ellicott.
References
External links
Home page and blog
1968 births
Living people
21st-century American astronomers
LGBTQ astronomers
American planetary scientists
Non-binary scientists
University of Arizona alumni
Fellows of the American Astronomical Society
American LGBTQ scientists | JA Grier | [
"Astronomy"
] | 355 | [
"Astronomers",
"LGBTQ astronomers"
] |
75,988,582 | https://en.wikipedia.org/wiki/Cefepime/enmetazobactam | Cefepime/enmetazobactam, sold under the brand name Exblifep, is a medication used for the treatment of urinary tract infections. It is a fixed dose combination containing cefepime, a cephalosporin antibacterial; and enmetazobactam, a beta-lactamase inhibitor.
The combination was approved for medical use in the United States in February 2024, and in the European Union in March 2024.
Medical uses
In the US, cefepime/enmetazobactam is indicated for the treatment of people with complicated urinary tract infections including pyelonephritis, caused by the following susceptible microorganisms: Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, Proteus mirabilis, and Enterobacter cloacae complex.
In the EU, cefepime/enmetazobactam is indicated for the treatment of complicated urinary tract infections, including pyelonephritis; hospital-acquired pneumonia, including ventilator-associated pneumonia; and the treatment of people with bacteremia that occurs in association with, or is suspected to be associated with, any of the infections listed above.
History
Enmetazobactam was invented by Orchid Pharma in India and then out-licensed to Allecra Therapeutics for further development.
Society and culture
Legal status
The combination was approved for medical use in the United States in February 2024.
In January 2024, the Committee for Medicinal Products for Human Use of the European Medicines Agency adopted a positive opinion, recommending the granting of a marketing authorization for the medicinal product Exblifep, intended for the treatment of urinary tract infections and pneumonia in adults. The applicant for this medicinal product is Advanz Pharma Limited. The combination was approved for medical use in the European Union in March 2024.
Names
The combination cefepime/enmetazobactam is sold under the brand name Exblifep.
References
Further reading
External links
Combination drugs | Cefepime/enmetazobactam | [
"Biology"
] | 440 | [
"Antibiotics",
"Biocides",
"Biotechnology products"
] |
75,988,894 | https://en.wikipedia.org/wiki/4-HO-NALT | 4-Hydroxy-N-allyltryptamine (4-HO-NALT) is a tryptamine derivative developed by modification of norpsilocin (4-HO-NMT). It produces a head-twitch response in mice consistent with psychedelic-like activity, as do the corresponding ethyl, propyl, isopropyl and benzyl derivatives (4-HO-NET, 4-HO-NPT, 4-HO-NiPT and 4-HO-NBnT), but the bulkier t-butyl and cyclohexyl derivatives are inactive.
See also
4-AcO-DALT
4-HO-MALT
5-HO-DiPT
5-MeO-T-NBOMe
NTBT
References
Secondary amines
Tryptamines
Allylamines | 4-HO-NALT | [
"Chemistry"
] | 171 | [
"Pharmacology",
"Pharmacology stubs",
"Medicinal chemistry stubs"
] |
75,990,148 | https://en.wikipedia.org/wiki/List%20of%20Redmi%20products | Redmi is a subsidiary company owned by the Chinese electronics company Xiaomi. Redmi's line of products ranges from smartphones and power banks to laptops, Smart TVs, and wireless earbuds, typically sold at a price lower than Xiaomi-branded ones.
This list is made according to Chinese names if the device has multiple names. The different models of each device model have differing details for different regions, in particular supporting a different range of frequency bands. Models have code names which relate to their firmware; only firmware with the right code is compatible. For example, the Redmi 10 India and Redmi 10 Power have interchangeable firmware (fog), but are not compatible with the Redmi 10 2022 (selenes).
Tablets
Phones
Redmi Series
Redmi Note Series
Redmi Turbo Series
Redmi K Series
Redmi A Series
Redmi TV
The first TV that Xiaomi introduced under the Redmi brand was the Redmi Smart TV 70-inch that debuted in China.
The Beijing-based company later expanded its Redmi TV portfolio by bringing the Redmi Smart TV X50, Redmi Smart TV X55, and the Redmi Smart TV X65 in May 2020. The catalogue further expanded with the Redmi Smart TV A series and Redmi Smart TV A65.
As of October 2023, the screen size of Redmi TV ranges from 32" to 100", with price ranging from RMB 899 to RMB 19999.
Redmi TV 70"
The Redmi TV was launched with 4K HDR display, quad core processor and PatchWall interface. It had Dolby Audio and DTS-HD audio technologies. It went on sale in China for CNY 3,799.
Redmi TV MAX 98
Coming to the features, the Redmi Smart TV Max 98-inch features a 4K display with 85 percent NTSC, wide colour gamut and 192 dynamic backlight zones. The Redmi Smart TV Max 98-inch is powered by a customised 12 nm chip, and it features MEMC motion compensation for smoother animation. The television packs 4 GB of RAM, and offers 64 GB of storage.
Redmi TV X (50/55/65 inches)
The TV has Reality Flow and Vivid Picture Engine as features meant to improve the viewing experience. Various sound formats are also supported, including Dolby Audio for the inbuilt speakers, Dolby Atmos pass-through over eARC, and DTS Virtual:X.
The television runs on Android TV 10, with the stock Android TV launcher and access to Google Assistant. Like other televisions from Xiaomi, it's also possible to access the PatchWall UI on the Redmi TV X Series, that is Xiaomi's content-focused, curated user interface that is popular on its Mi TV range. There is also Google Chromecast built in, and the Redmi TV range is the first from the company to have the Mi Home app for IoT products supported on the TVs.
Redmi TV A (32/43/50/55/65 inches)
The TV packs 1.5 GB of RAM and come with 8 GB of internal storage. There's also Stereo Speakers that are claimed to offer more immersive sound, along with DTS decoding support.
It is running the MIUI operating system based on Android which can also be used to control smart home devices through voice commands. The company has also introduced a new Minimalist Mode so that elders can easily navigate through the interface.
Redmi TV MAX 86
Released in February 2021
Redmi TV MAX 100
Released in March 2022
Redmi TV MAX 90
Released in April 2023
Redmi Washing Machine
As of May 2020, Redmi has a total of 2 top load washer models.
RedmiBook Laptop
Redmi accessories
Redmi accessories ranges from wireless earbuds, power banks, Internet routers to smart AI speakers.
See also
List of Realme products
References
Lists of mobile phones
Smart TV
Xiaomi | List of Redmi products | [
"Technology"
] | 815 | [
"Multimedia",
"Smart TV"
] |
74,493,145 | https://en.wikipedia.org/wiki/GTFS%20Realtime | GTFS Realtime (also known as GTFS-rt) is an extension to GTFS, in which public transport agencies share real-time vehicle locations, arrival time predictions, and alerts such as detours and cancellations via Protocol Buffers web server.
Realtime location data is created continuously by an agency from automatic vehicle location (AVL) systems. Trip arrival times are computed using machine learning models that analyse historical positional data and timetables.
The standard is used by public transport agencies globally, including the United States, Canada, most countries in the European Union, United Kingdom, Australia, New Zealand, and in Yokohama, Japan.
History
On 22 August 2011, a first version of GTFS-rt was released by Google. This data was shown to Google Maps users.
In July 2012, Google Maps began showing alerts from GTFS-rt.
A proposal that was created on July 28, 2015 and merged on Aug 15, 2015 allowed the combination of several feed entity types into a single feed. While the majority of agencies separate feed entity types (Vehicle Positions, Trips, and Alerts), some feeds are still joined.
On August 30, 2021, an experimental feed entity types, Shapes, was released. Shapes has the ability to update route shapes in real time to reflect detour, as route updates are either reflected by referencing an existing shape_id or by defining in real time a new shape as an encoded polyline.
In 2022, CalTrans' Integrated Travel Project began validating GTFS Schedule and Realtime feeds published by municipality and county public transport agencies within California. Monthly reports are published on the errors in agency data, along with analysis of typical street speeds and traffic.
In September 2023, Swiftly and the app Transit proposed 2 additional feed entity types: Stop and Trip Modifications. These allow agencies to broadcast new detour paths of routes and new temporary stops. The change has been released to users in the Transit app across several agencies. On March 11, 2024, the proposal was merged and released by GTFS maintainers.
Standard
The GTFS Realtime specification is defined by a .proto file hosted by Google. Data is serialized into raw bytes by the server and then deserialized by a client. Officially supported GTFS-rt binding libraries have been built in .NET, Java, Javascript, Python, and Go. Unofficial libraries have been written in other languages, such as Rust.
There are currently three official feed types defined in the standard, TripUpdates, VehiclePositions, and Alerts. Shapes, Trip Modifications, and Stops are currently experimental.
Agencies supporting GTFS-Realtime typically provide separate urls for the three separate feed types, and may choose to only provide some of the feeds. Unlike GTFS Schedule zip files, many agencies may require developers to request an API key via email or a web form.
Developers then write programs to periodically fetch an agency's web API over HTTP, typically every few seconds to minutes. Agencies typically refresh data in frequencies ranging between 1 second to 1 minute. There is no standard for streaming GTFS Realtime data, also support is built in to allow for deletion of items from previous iterations.
Trip updates
In the GTFS Specification, a trip refers to an operator driving a fixed-route vehicle from the start of the route to the end. A new trip is started for when the vehicle turns around at the end of its route.
The Trip Update feed allows maps to show the departure or arrival times of vehicles, and allows routing algorithms to update their directions.
This feed contains an array of Trip Updates. Each trip update enumerates a description of a trip (trip id, route id, start time and date, direction), last updated time, may include an associated vehicle number and route number, and contains an array of StopTimeUpdate. The StopTimeUpdate can define past, current, and future stop times, delays, and cancellations. The stop id references the GTFS Schedule feed the agency provides.
Vehicle positions
Vehicle Positions are sometimes shown on mapping applications to aid users in tracking the location of buses. This feed contains an array of VehiclePositions. Like Trip Updates, each VehiclePosition can also contain a basic description of the trip, such as its trip id, start and stop times, route number, and relationship to the schedule. The VehiclePosition also contains the current latitude and longitude of the vehicle, and can also include bearing, odometer, and speed in m/s. Finally, it can also contain information on how crowded the bus is, known as occupancy status, and status of road congestion experienced by the vehicle.
Alerts
Alerts can be shown to mapping application users to alert them of detours, cancellations, or other service changes. This feed contains an array of Alerts. Alerts typically don't update as often as Vehicle Positions or Trip Updates. Each Alert stores the cause (such as labour strike or a mechanical fault) of an incident, along with its effect (reduced service, detour, stop cancellation, etc.). Alerts also contain detailed headers, descriptions, urls, images, and a list of routes or stops affected (known as the Informed Entity). Alerts specify their beginning and expiration times using "active periods". Alerts can be localised into several languages.
References
Public transport information systems
Scheduling (transportation)
Web syndication formats
Computer file formats
Real-time computing | GTFS Realtime | [
"Technology"
] | 1,110 | [
"Public transport information systems",
"Information systems",
"Real-time computing"
] |
74,493,523 | https://en.wikipedia.org/wiki/Internal%20carotid%20venous%20plexus | The internal carotid venous plexus is a network of veins surrounding the internal carotid artery as it passes through the carotid canal. The plexus interconnects the internal jugular vein (extracranially) and cavernous sinus (intracranially).
References
Anatomy | Internal carotid venous plexus | [
"Biology"
] | 67 | [
"Anatomy"
] |
74,495,660 | https://en.wikipedia.org/wiki/Brazilian%20Nonproprietary%20Name | The Brazilian Nonproprietary Name or DCB, from the Portuguese Denominação Comum Brasileira is the official Portuguese nomenclature for drugs or active ingredients that have been approved by the Brazilian Health Regulatory Agency (ANVISA) for use in Brazil. The consolidated list from October 2021 contains just over 12,300 items.
Every record has a numerical identifier known as the DCB Number, used in contexts such as registrations, tenders and official documentation.
History
In 1970 Andrejus Korolkovas, from the Faculty of Pharmaceutical Sciences, University of São Paulo, was already publishing about the importance of a nomenclature to harmonize the names of drugs. In the year 1981, a list of generic names that would be mandatory for a new registration of a medicine was published in the Official Gazette of the Union, by the Ministry of Health. A standardization of nomenclature was carried out, and the introduction of numerical codes that would allow the identification of the substances. In 1983 the use of the standard nomenclature in official documents was made mandatory.
See also
International Nonproprietary Name
British Approved Name
United States Adopted Name
Interactive Terminology for Europe
IUPAC nomenclature
References
Pharmacological classification systems | Brazilian Nonproprietary Name | [
"Chemistry"
] | 244 | [
"Pharmacological classification systems",
"Pharmacology"
] |
74,496,257 | https://en.wikipedia.org/wiki/EXtreme%20Gammon | eXtreme Gammon is backgammon software written by Xavier Dufaure de Citres and released in 2009. It is available for Microsoft Windows and mobile platforms.
According to the Financial Times, the program is the best backgammon player in the world, and the near-exclusive study tool for all serious backgammon players.
Performance rating
eXtreme Gammon provides a widely accepted benchmark number for players' skills called the Performance Rating or PR, with a lower number indicating a better rating. PR is the average equity lost per decision multiplied by 500. Only decisions not considered to be "obvious" are counted.
References
External links
Backgammon
Game artificial intelligence | EXtreme Gammon | [
"Mathematics"
] | 133 | [
"Game theory",
"Game artificial intelligence"
] |
74,496,313 | https://en.wikipedia.org/wiki/Generative%20literature | Generative literature is poetry or fiction that is automatically generated, often using computers. It is a genre of electronic literature, and also related to generative art.
John Clark's Latin Verse Machine (1830–1843) is probably the first example of mechanised generative literature, while Christopher Strachey's love letter generator (1952) is the first digital example. With the large language models (LLMs) of the 2020s, generative literature is becoming increasingly common.
Definitions
Hannes Bajohr defines generative literature as literature involving "the automatic production of text according to predetermined parameters, usually following a combinatory, sometimes aleatory logic, and it emphasizes the production rather than the reception of the work (unlike, say, hypertext)."
In his book Electronic Literature, Scott Rettberg connects generative literature to avant-garde literary movements like Dada, Surrealism, Oulipo and Fluxus. Bajohr argues that conceptual art is also an important reference.
Paradigms of generative literature
Bajohr describes two main paradigms of generative literature: the sequential paradigm, where the text generation is "executed as a sequence of rule-steps" and employs linear algorithms, and the connectionist paradigm, which is based on neural nets. The latter leads to what Bajohr calls a algorithmic empathy: "a non-anthropocentric empathy aimed not at the psychological states of the artists but at understanding the process of the work’s material production."
Poetry generation
The first examples of automated generative literature are poetry: John Clark's mechanical Latin Verse Machine (1830–1843) produced lines of hexameter verse in Latin, and Christopher Strachey's love letter generator (1952), programmed on the Manchester Mark 1 computer, generated short, satirical love letters.
Examples of generative poetry using artificial neural networks include David Jhave Johnston's ReRites.
Narrative generation
Story generators have often followed specific narratological theories of how stories are constructed. An early example is Grimes' Fairy Tales, the "first to take a grammar-based approach and the first to operationalize Propp's famous model." Mike Sharples and Rafael Peréz y Peréz's book Story Machines gives a detailed history of story generation.
Storyland by Nanette Wylde is an example of generative narrative. Jonathan Baillehache compares Storyland to Surrealist writing. Baillehache states, "When compared to earlier uses of chance operation in literature, a piece like this one resembles some of the automatic writings produced by André Breton and Philippe Soupault in their collective work The Magnetic Fields. . . The difference between Nanette Wylde’s Storyland and Breton and Soupault’s Magnetic Fields is that the former is produced according to a computational algorithm involving randomizers and user interaction, and the latter by two free-wheeling human subjects."
References
New media art
Generative artificial intelligence
Generative literature
Poetry movements | Generative literature | [
"Engineering"
] | 610 | [
"Artificial intelligence engineering",
"Generative artificial intelligence"
] |
74,497,471 | https://en.wikipedia.org/wiki/GRESB | GRESB is a Netherlands-based company that operates an annual sustainability assessment for standing real estate investments, real estate projects in development, infrastructure funds, and infrastructure assets. From these assessments, it provides standardized and validated environmental, social, and governance (ESG) data and benchmarks for the real assets investment community. Academic research has demonstrated that GRESB participation is a predicator of fund-level financial returns.
History and organizational structure
GRESB was established in 2009 as a collaboration between a group of pension funds and Maastricht University to assess the sustainability of real estate fund managers, later expanding into infrastructure. In 2014 the company was acquired by GBCI and then sold in 2020 through a management buyout in conjunction with Summit Partners. In 2024, General Atlantic acquired a majority stake in GRESB.
Today, GRESB is a certified B Corp with an associated but independent not-for-profit foundation that owns and governs the ESG standards upon which the GRESB assessments are based.
Assessment structure and impact
The annual results and benchmarks from GRESB's real estate and infrastructure assessments are used by fund managers to better understand their portfolio's relative performance against peers and by investors looking for standardized disclosures into a fund or firm's ESG strategies and performance. Recent scholarship suggests that over the past few years there has been significant adoption of and reporting to GRESB within the real estate industry and that GRESB participation and performance are both significant predicators of cross-sectoral fund returns. The relationship between GRESB, its foundation, and the industry representatives that sit on the foundation's board has been criticized as allowing investors too much freedom to set the standards that funds are evaluated against.
Indices
The GRESB Global Sustainable Index was launched in 2006, while the iEdge-UOB APAC Green REIT index was launched in 2021.
References
Ethical investment
Governance
Market data
Environmentalism
2009 establishments in the Netherlands | GRESB | [
"Technology"
] | 400 | [
"Market data",
"Data"
] |
74,498,317 | https://en.wikipedia.org/wiki/Safe%20Routes%20to%20School | Safe Routes to School programs are a public health initiative in the United States and elsewhere designed to encourage more children to walk or cycle to and from school.
In the US, a Safe Routes to School program was first formed and funded on the national level as part of the 2005 federal transportation bill known as SAFETEA-LU.
References
Public health in the United States
Student transport
Health and transport
Urban planning in the United States
Pedestrian activism | Safe Routes to School | [
"Physics"
] | 86 | [
"Physical systems",
"Transport",
"Transport stubs"
] |
74,501,954 | https://en.wikipedia.org/wiki/Bd%C3%B3te | Bdóte ( ""; ; deprecated spelling Mdote) is a significant Dakota sacred landscape where the Minnesota and Mississippi Rivers meet, encompassing Pike Island, Fort Snelling, Coldwater Spring, Indian Mounds Park, and surrounding areas in present-day Minneapolis and Saint Paul, Minnesota, United States. In Dakota geographic memory, it is a single contiguous area not delineated by any contemporary areas' borders. According to Dakota oral tradition, it is the site of creation; the interconnectedness between the rivers, earth, and sky are important to the Dakota worldview and the site maintains its significance to the Dakota people.
It is also an important location in the history of European colonization of the region, including the 1805 Treaty of St. Peters with the Dakota people and the 1837 Treaty of St. Peters with the Ojibwe. After the Dakota War of 1862, it was the location of the concentration camp of the Dakota people before they were forcibly exiled from Minnesota. The cities of Mendota and Mendota Heights, Minnesota, which are part of Bdote, take their names from the Dakota name for the region.
In recent years, a movement to recognize and protect Bdote as a sacred place has been growing.
Etymology
In the Dakota language, can refer to any place where two bodies of water converge and can be translated as the "mouth" of a body of water. A deprecated spelling is .
Sacred significance to the Dakota people
Cosmology
Numerous creation stories within the Dakota communities define their relationships with the land and the stars above, including the sacred sites in Bdote. Many Dakota people identify as part of the Wicahpi Oyate (Star Nation), having spiritually originated from the stars and come into being on the land. In one version, the Big Dipper represents the seven bands of the Dakota and Lakota, collectively known as the Oceti Sakowin (Seven Council Fires). According to another, told by Gwen Westerman, the Dakota came from Orion's Belt and through the Creator, they walked Caŋku Wanagi, the “spirit road" (Milky Way), and arrived at Bdote, later spreading out to establish the sacred sites in the surrounding areas.
At Bdote, two bluffs called Caṡḳe Taŋka and Caṡḳe Cistiŋna opened up the earth. The Creator used mud between the bluffs to form the first Dakota man and woman. The earth is called Ina for "mother" because it is where Dakota people came from. Ṡuŋġi (Dakota elder Reverend Gary Cavender) further explains, "In our Creation myth we the Dakota, the Seven Fires of the Dakota, came from the belt of Orion—the seven planets of the belt of Orion, the seven stars—and arrived at the convolution of the Minnesota and Mississippi Rivers, and so in some respects it is our Eden, and the land around there is sacred as well".
According to astronomer Jim Rock, Bdote refers to the "Dakota Makoce Cokaya Kin" (Dakota center of the universe). An ancient and important relationship between the land and stars is known by the Dakota term Kapemni, which means "as it is above, it is below". The Mississippi River is reflected above as the Milky Way, the Spirit Road, that life travels to this world and returns to. Burial mounds, including Oheyawahi-Pilot Knob and Indian Mounds Park within Bdote, are built along the bluffs overlooking the Mississippi River so that the ancestors are in a place of honor.
A newborn baby's first cry is referred to as bdote, which compares the importance of a person's first breath of air with the necessity of water for life.
Sacred sites
There are numerous sites sacred to the Dakota people within Bdote. The specific sites within Bdote are part of what gives the region its significance in Dakota tradition. Lakota Chief Arvol Looking Horse noted during a pipe ceremony on Pilot Knob Preservation (Oheyawahi) that these sacred sites are how Dakota people connect spiritually to the wider landscape. Prairie Island Dakota spiritual leader Chris Leith has said that Bdote's many sacred sites make it a "vortex" in the landscape.
Mnísota Wakpá (Minnesota River)
Oȟéyawahe (Pilot Knob Preservation)
Wíta Tháŋka (Pike Island)
Mniówe Sní (Coldwater Spring)
Owámniyomni (St. Anthony Falls)
Ȟaȟáwakpa (Mississippi River)
Ȟaȟáwakpa ("river of waterfalls", also known as the Mississippi River) was named after the many waterfalls that once cascaded over the bluffs, and the only natural waterfall on the Mississippi River, known in Dakota as Owámniyomni (St. Anthony Falls). Urban development of Minneapolis and Saint Paul led to the destruction of many of the falls or the removal of their water source. The river is reflected above in Dakota thought as the Milky Way, known in Dakota star knowledge as the Spirit Road on which people's spirits travel to and from earth during their birth and death. According to Dakota oral tradition, burial mounds were built along the bluffs to be close to the river of waterfalls and the spirit road. The river is also called Wakpá Tháŋka, the Great River, or less commonly Thaŋčháŋ Wakpa ("the body or principal part anything river").
Owámniyomni (St. Anthony Falls)
Owámniyomni ("whirlpool") is the Dakota name of St. Anthony Falls. As the only natural portage on the Mississippi River in the area, it was considered neutral territory and a practical meeting place for numerous tribes (including the Dakota, Hochunk and, later, the Ojibwe). Above the sacred falls is Wita Waste ("Beautiful Island" or Nicollet Island), an annual maple-sugar camp for the Dakota. Below the falls was an island known as Wita Wanagi ("Spirit Island"), which the U.S. Army Corps of Engineers destroyed in 1960 to dredge the site for boat passage. Wita Wanagi was a birthing place for Dakota women and also home to the spirit of Anpetu Sapa Win ("Clouded Day Woman"), whose death song could still be heard on the island.
Wakháŋ Thípi
Wakháŋ Thípi ("dwelling place of the sacred", also known as Carver's Cave) is a spring-fed cave, sealed with an iron gate, within the Bruce Vento Nature Sanctuary. Dakota people believe it is home to an Uŋktehi (underwater serpent) that protects the water. Dakota midwife Autumn Cavendar-Wilson describes the cave as a historical safe location for generations of Dakota women to give birth that represents a womb on earth. The cave corresponds with Orion's belt as a reflection on earth. There were petroglyphs of snakes that depicted the Dakota people's cosmic origin beliefs at Bdote and Wakháŋ Thípi. A railroad expansion project in the late 1800s destroyed the atrium of the cave that contained the petroglyphs.
Burial sites
Indian Mounds Regional Park, Oheyawahi-Pilot Knob Preservation Site, Mound Springs Park, and Grey Cloud Island are considered burial sites by Dakota people and parks by governing municipalities.
Geography
Bdote refers to both a wider geographical area and the northeastern tip of Pike Island specifically, which is considered the exact area where the Mississippi River (Wakpá Táŋka) and Minnesota Rivers meet.
The exact area of wider Bdote varies by tradition, but generally encompasses Pike Island, Fort Snelling, Saint Anthony Falls, Coldwater Spring, and a stretch of the Minnesota and Mississippi Rivers. It has no English name and is popularly known by its Dakota name, . Its role in Dakota tradition is sometimes described in English as "the center", a site that is the start of all life.
The rivers and island are south of Minneapolis and St. Paul and north of Mendota, Minnesota. Most of the Bdote area is administered by the state as part of the Fort Snelling state park and historic site, or Minneapolis-Saint Paul International Airport, while Crosby Farm Park and Hidden Falls are St. Paul city parks. Coldwater Spring (Mniówe Sní), along with Saint Anthony Falls (Owámniyomni, lit. "whirlpool"), are under federal jurisdiction as part of the Mississippi National River and Recreation Area.
History
Dakota villages and settlements
Because the Dakota observed a seasonal migration pattern, a number of villages and settlements were noted in the Bdote area. In the location-based Dakota history book Mni Sota Makoce, Westerman and White posit that burial mounds correlate with village locations, because some mound research has revealed relationships between Dakota seasonal settlement and mound activity. This relationship is already noted in Dakota oral traditions.
Villages settled in a similar area each year, though the exact location varied. For example, in 1805 Kaposia (Kap’oża) was noted at the site of present-day Mounds Park in St. Paul, and around the time of the Treaty of 1837, Kaposia moved from the east bank of the Mississippi River to the west bank (a place now called Kaposia Landing Park and Kaposia Indian Site), and in 1853 Kaposia moved again due to provisions in the Treaty of Mendota. Sites in Bdote were more likely summer villages, where spring flooding made travel by canoe more convenient.
Kaposia (Kap’oża): Near Mounds Park and Bruce Vento Nature Sanctuary
Black Dog village (Ohaŋska): Near the present-day site of Fort Snelling
Ḣeyate Otunwe: Maḣpiya Wic̣aṡṭa (Cloud Man)'s village on Bde Maka Ska, where Dakota experimented with Western-style sedentary agricultural practices. Cloud Man died in the Fort Snelling concentration camp at Wíta Tháŋka (Pike Island) in the winter of 1862-1863.
Treaty of St. Peters
At Bdote, Zebulon Pike met with the Dakota and signed the 1805 Treaty of St. Peters, also known as Pike's Purchase. Two of the seven Dakota leaders agreed to sell the land, eventually receiving only $2,000 when it was valued by Pike at $200,000, along with the agreement to build a fort at the location. In 1820, the Dakota granted ownership of where the two rivers meet on Bdote (Pike Island) to Pelagie Ainse, the daughter of a French fur trader and a Dakota woman. She was married to Jean-Baptiste Faribault and was the mother of Alexander Faribault.
Fort Snelling concentration camp
While Bdote is the origin story of the Dakota people, it is also the site of their forced exile from Minnesota. The Fort Snelling Dakota concentration camp at Bdote was a temporary holding facility for Dakota women, children, and elders who surrendered to the U.S. military after the Dakota War of 1862. The camp was on the banks of the Minnesota River, near the fort. It was established in November 1862 and held about 1,700 Dakota people. The conditions in the camp were miserable, and between 130 and 300 Dakota people died died from disease and malnutrition. Dakota leader Gabriel Renville wrote: "We were so crowded and confined that an epidemic broke out among us and children were dying day and night. Amid all this sickness and these great tribulations, it seemed doubtful at night whether a person would be alive in the morning".
In December 1862, the U.S. military built a wooden stockade around the camp. The stockade was about 12 feet high and enclosed an area of two or three acres. The Dakota people were forced to live inside the stockade and not allowed to leave. The camp was guarded by soldiers from the Sixth, Seventh, and Tenth Minnesota Volunteer Infantry Regiments. The soldiers were responsible for controlling movement in and out of the camp.
Episcopalian Bishop Henry Benjamin Whipple advocated for the imprisoned Dakota people, and Reverend John Poage Williamson, who lived among the Dakota his whole life, joined them in the ordeal and remained with them as they were exiled into South Dakota. The concentration camp at Fort Snelling closed in May 1863 and the Dakota people who survived the camp were then exiled from Minnesota to the Crow Creek Reservation in South Dakota.
Restoration attempts
There has recently been a growing movement to recognize and protect Bdote and the sites it encompasses as a sacred place. The Minnesota Humanities Center launched the Bdote Memory Map, an interactive online map that tells the story of Bdote from a Dakota perspective.
In 2019, 44 Minnesota House Democrats sent the Minnesota Historical Society a letter in support of adding Bdote to signage at Historic Fort Snelling. In 2021, Henry Sibley High School in Mendota Heights was renamed Two Rivers High School due to its proximity to Bdote. The school's former namesake, Henry Hastings Sibley, played a major role in the Dakota War of 1862 and the mass hanging of 38 Dakota men.
In 2021, Oglala Lakota chef Sean Sherman opened the restaurant Owamni at the site of Owámniyomni (Saint Anthony Falls); it serves dishes made only with ingredients indigenous to the Americas. Partnering with Sherman, the Minneapolis Park and Recreation Board and Parks Foundation raised money to open the restaurant in order to honor the Dakota heritage of the falls. It won Best New Restaurant at the 2022 James Beard Awards.
Fort Snelling redesign
An attempt to add "at Bdote" to the signage at Fort Snelling failed in 2019 after Republican lawmakers attempted to revoke $4 million in funding for the Minnesota Historical Society (MHS), which manages the Fort Snelling territory. The MHS board unanimously voted to continue with the current site name, citing no conclusive evidence to support renaming it from their research in the community. Native leaders and communities condemned the decision to withdraw engagement in the restoration of the Dakota name for the area.
In the 2016 legislative session, the MHS sought $34 million in bonding to redesign and restore the fort and territory. This included remodeling a barracks into a visitor's center, tearing down the existing center, and building an amphitheater. Included in the project plan and budget was funding for renewed marketing, historical research, exhibit redesign, and community outreach and engagement, particularly with local Native communities and leaders. The MHS formed the Dakota Community Council in 2017 as part of its engagement effort.
Wakaŋ Tipi site reclamation
The Wakan Tipi Awanyankapi ("those who care for Wakan Tipi", formerly known as the Lower Phalen Creek project) is a Dakota-led organization that advocates for the restoration of native habitat and Indigenous histories to the Bruce Vento Nature Sanctuary and surrounding areas. They are building the Wakan Tipi Center at the sanctuary, which will be an immersive way to learn Dakota history, lifeways, language, and values. WTA and the City of St. Paul announced a co-management agreement for the site in 2024. Other goals include restoring Phalen Creek above ground and renaming Carver's Cave to the original Dakota name of Wakan Tipi.
Owámniyomni site reclamation
The Owámniyomni Okhódayapi ("Friends of the Falls") is a Dakota-led organization that is working to restore the falls to a natural state and return Dakota leadership to the management of the site. It is working with the city of Minneapolis for transfer of land surrounding the Upper Lock and Dam from the federal government (U.S. Army Corps of Engineers). The Army Corps of Engineers is expected to make a decision on the land transfer in 2024.
In art and culture
Minnesota state poet laureate Gwen Westerman writes about Dakota culture, frequently featuring Bdote. In De Wakpa Taŋka Odowaŋ / Song for the Mississippi River, she writes: "To Bdote, the beginning / of the Mississippi of the North / and the Little Minnesota. / These were our waterways / and our lifeways. / Our medicine." Author Heid E. Erdrich released the poem-film "Pre-Occupied", a critique of settler colonial themes in the Occupy Movement that alludes to Bdote's central role in the Dakota worldview.
See also
History of Minnesota
References
Bibliography
Citations
External links
Bdote Memory Map, Minnesota Humanities Center
Creation myths
Dakota culture
Dakota toponyms
History of Minnesota
Religious places of the Indigenous peoples of North America
Sacred waters
Minnesota placenames of Native American origin | Bdóte | [
"Astronomy"
] | 3,426 | [
"Cosmogony",
"Creation myths"
] |
74,502,376 | https://en.wikipedia.org/wiki/Nutritional%20psychiatry | Nutritional psychiatry is the clinical application of psychiatry to treat nutrition psychology through diet which impacts mental health.
Nutrional psychiatry is an emerging field and conducts interventions through nutraceuticals and psychobiotics.
References
Academic disciplines
Behavioural sciences
Branches of psychology
Mental disorders
Social sciences | Nutritional psychiatry | [
"Biology"
] | 56 | [
"Mental disorders",
"Behavior",
"Behavioural sciences",
"Human behavior"
] |
74,503,203 | https://en.wikipedia.org/wiki/AOH1996 | AOH1996 is an experimental anticancer medication which acts as a small molecule inhibitor of proliferating cell nuclear antigen (PCNA) and is in Phase I clinical trials at City of Hope as of August 2023 for the treatment of solid tumors.
AOH1996 was created to target a post-translationally modified isoform of PCNA, termed caPCNA, which is preferentially found in cancer cells. PCNA is crucial in the body for DNA repair, but targeting it is difficult because of its role in healthy cells. By selectively targeting caPCNA, it may be possible to kill cancer cells without affecting healthy tissues. In vitro testing demonstrated that AOH1996 inhibited the growth and induced cell cycle arrest and apoptotic cell death in a wide variety of cancer cell lines, but had no effect on several normal, nonmalignant cell types. In mouse and dog animal models, there were no observed side effects or toxicity even at six times the effective dose. It could be used either as a monotherapy (single drug regimen) or in combination with one or more other chemotherapy drugs.
Although the press described it as a "miracle drug" that would cure cancer, some experts have expressed skepticism. Prof Dorothy Bennett, Director of the Molecular and Clinical Sciences Research Institute, St George’s, University of London, critiqued the paper's cancer killing claim as actually a modest slowing of growth but, "there appears to be broad evidence here.... suggesting that this kind of approach deserves further development.”
The substance was named after the initials and the birth year of Anna Olivia Healey, who died of neuroblastoma in 2006. The funds collected by her parents have helped support the development of the chemical compound.
References
External links
Enzyme inhibitors
Experimental cancer drugs
1-Naphthyl compounds
Acetamides
3-Methoxyphenyl compounds | AOH1996 | [
"Chemistry"
] | 390 | [
"Pharmacology",
"Pharmacology stubs",
"Medicinal chemistry stubs"
] |
74,503,453 | https://en.wikipedia.org/wiki/S/2006%20S%209 | S/2006 S 9 is a natural satellite of Saturn. Its discovery was announced by Scott S. Sheppard, David C. Jewitt, Jan Kleyna, Edward Ashton, Brett J. Gladman, Jean-Marc Petit and Mike Alexandersen on May 3, 2023 from observations taken between February 1, 2006 and July 1, 2021.
S/2006 S 9 is about 3 kilometers in diameter, and orbits Saturn at a distance of 14.407 Gm in 648.71 days, at an inclination of 173.0, orbits in retrograde direction and eccentricity of 0.248. S/2006 S 9 belongs to the Norse group and it could possibly be a Phoebe fragment like S/2006 S 20, since it orbits at close proximity to Phoebe.
References
Norse group
Irregular satellites
Moons of Saturn
Astronomical objects discovered in 2023
Moons with a retrograde orbit | S/2006 S 9 | [
"Astronomy"
] | 177 | [
"Astronomy stubs",
"Planetary science stubs"
] |
74,503,495 | https://en.wikipedia.org/wiki/S/2007%20S%205 | S/2007 S 5 is a natural satellite of Saturn. Its discovery was announced by Scott S. Sheppard, David C. Jewitt, Jan Kleyna, Edward Ashton, Brett J. Gladman, Jean-Marc Petit and Mike Alexandersen on May 3, 2023 from observations taken between January 5, 2005 and July 9, 2021.
S/2007 S 5 is about 4 kilometers in diameter, and orbits Saturn at a distance of 15.836 Gm in 746.88 days, at an inclination of 158.4, orbits in retrograde direction and eccentricity of 0.104. S/2007 S 5 belongs to the Norse group and its orbit is quite circular due to of its low eccentricity unlike the other irregular moons.
References
Norse group
Irregular satellites
Moons of Saturn
Astronomical objects discovered in 2023
Moons with a retrograde orbit | S/2007 S 5 | [
"Astronomy"
] | 173 | [
"Astronomy stubs",
"Planetary science stubs"
] |
74,503,571 | https://en.wikipedia.org/wiki/S/2019%20S%202 | S/2019 S 2 is a natural satellite of Saturn. Its discovery was announced by Edward Ashton, Brett J. Gladman, Jean-Marc Petit and Mike Alexandersen on May 3, 2023 from observations taken between July 3, 2019 and July 9, 2021.
S/2019 S 2 is about 3 kilometers in diameter, and orbits Saturn at a distance of 16.560 Gm in 796.22 days, at an inclination of 173.3, orbits in retrograde direction and eccentricity of 0.279. S/2019 S 2 belongs to the Norse group and makes it close to 0 tilt against the ecliptic plane due to of its inclination.
References
Norse group
Irregular satellites
Moons of Saturn
Astronomical objects discovered in 2023
Moons with a retrograde orbit | S/2019 S 2 | [
"Astronomy"
] | 156 | [
"Astronomy stubs",
"Planetary science stubs"
] |
74,503,763 | https://en.wikipedia.org/wiki/S/2020%20S%203 | S/2020 S 3 is a natural satellite of Saturn. Its discovery was announced by Edward Ashton, Brett J. Gladman, Jean-Marc Petit and Mike Alexandersen on May 5, 2023 from observations taken between July 3, 2019 and July 9, 2021.
S/2020 S 3 is about 3 kilometers in diameter, and orbits Saturn at a distance of 17.930 Gm in 896.35 days, at an inclination of 47.1, orbits in prograde direction and eccentricity of 0.038. S/2020 S 3 belongs to the Inuit group, it may be a Siarnaq fragment that broke off long ago, since it shares the same orbital elements and its orbit is quite circular due to of its low eccentricity unlike the other irregular moons.
References
Inuit group
Irregular satellites
Moons of Saturn
Moons with a prograde orbit
Astronomical objects discovered in 2023 | S/2020 S 3 | [
"Astronomy"
] | 180 | [
"Astronomy stubs",
"Planetary science stubs"
] |
74,503,991 | https://en.wikipedia.org/wiki/Oppenheimer%E2%80%93Snyder%20model | In general relativity, the Oppenheimer–Snyder model is a solution to the Einstein field equations based on the Schwarzschild metric describing the collapse of an object of extreme mass into a black hole. It is named after physicists J. Robert Oppenheimer and Hartland Snyder, who published it in 1939.
During the collapse of a star to a black hole the geometry on the outside of the sphere is the Schwarzschild geometry. However the geometry inside is, curiously enough, the same Robertson-Walker geometry as in the rest of the observable universe.
History
Albert Einstein, who had developed his theory of general relativity in 1915, initially denied the possibility of black holes, even though they were a genuine implication of the Schwarzschild metric, obtained by Karl Schwarzschild in 1916, the first known non-trivial exact solution to Einstein's field equations. In 1939, Einstein published "On a Stationary System with Spherical Symmetry Consisting of Many Gravitating Masses" in the Annals of Mathematics, claiming to provide "a clear understanding as to why these 'Schwarzschild singularities' do not exist in physical reality."
Months after the issuing of Einstein's article, J. Robert Oppenheimer and his student Hartland Snyder studied this topic with their paper "On Continued Gravitational Contraction" making the opposite argument as Einstein's. They showed when a sufficiently massive star runs out of thermonuclear fuel, it will undergo continued gravitational contraction and become separated from the rest of the universe by a boundary called the event horizon, which not even light can escape. This paper predicted the existence of what are today known as black holes. The term "black hole" was coined decades later, in the fall of 1967, by John Archibald Wheeler at a conference held by the Goddard Institute for Space Studies in New York City; it appeared for the first time in print the following year. Oppenheimer and Snyder used Einstein's own theory of gravity to prove how black holes could develop for the first time in contemporary physics, but without referencing the aforementioned article by Einstein. Oppenheimer and Snyder did, however, refer to an earlier article by Oppenheimer and Volkoff on neutron stars, improving upon the work of Lev Davidovich Landau. Previously, and in the same year, Oppenheimer and three colleagues, Richard Tolman, Robert Serber, and George Volkoff, had investigated the stability of neutron stars, obtaining the Tolman-Oppenheimer-Volkoff limit. Oppenheimer would not revisit the topic in future publications.
Model
The Oppenheimer–Snyder model of continued gravitational collapse is described by the line element
The quantities appearing in this expression are as follows:
The coordinates are where are coordinates for the 2-sphere.
is a positive quantity, the "boundary radius", representing the boundary of the matter region.
is a positive quantity, the mass.
and .
is defined implicitly by the equation
.
This expression is valid both in the matter region , and the vacuum region , and continuously transitions between the two.
Reception and legacy
Kip Thorne recalled that physicists were initially skeptical of the model, viewing it as "truly strange" at the time. He explained further, "It was hard for people of that era to understand the paper because the things that were being smoked out of the mathematics were so different from any mental picture of how things should behave in the universe." Oppenheimer himself thought little of this discovery. However, some considered the model's discovery to be more significant than Oppenheimer did, and model would later be described as forward thinking. Freeman Dyson thought it was Oppenheimer's greatest contribution to science. Lev Davidovich Landau added the Oppenheimer-Snyder paper to his "golden list" of classic papers. John Archibald Wheeler was initially an opponent of the model until the late 1950s, when he was asked to teach a course on general relativity at Princeton University. Wheeler claimed at a conference in 1958 that the Oppenheimer-Snyder model had neglected the many features of a realistic star. However, he later changed his mind completely after being informed by Edward Teller that a computer simulation ran by Stirling Colgate and his team at the Lawrence Livermore National Laboratory had shown a sufficiently heavy star would undergo continued gravitational contraction in a manner similar to the idealized scenario described by Oppenheimer and Snyder. Wheeler subsequently played a key role in reviving interest in general relativity in the United States, and popularized the term "black hole" in the late 1960s. Various theoretical physicists pursued this topic and by the late 1960s and early 1970s, advances in observational astronomy, such as radio telescopes, changed the attitude of the scientific community. Pulsars had already been discovered and black holes were no longer considered mere textbook curiosities. Cygnus X-1, the first solid black-hole candidate, was discovered by the Uhuru X-ray space telescope in 1971. Jeremy Bernstein described it as "one of the great papers in twentieth-century physics."
After winning the Nobel Prize in Physics in 2020, Roger Penrose would credit the Oppenheimer–Snyder model as one of his inspirations for research.
The Hindu wrote in 2023:
In popular culture
In the 2023 film Oppenheimer, an interaction between Oppenheimer and his student Snyder occurs as their paper was published on the same day as the Invasion of Poland.
See also
Tolman–Oppenheimer–Volkoff equation
Timeline of gravitational physics and relativity
References
Astrophysics
Black holes | Oppenheimer–Snyder model | [
"Physics",
"Astronomy"
] | 1,122 | [
"Black holes",
"Physical phenomena",
"Physical quantities",
"Unsolved problems in physics",
"Astrophysics",
"Density",
"Stellar phenomena",
"Astronomical objects",
"Astronomical sub-disciplines"
] |
74,504,228 | https://en.wikipedia.org/wiki/S/2020%20S%205 | S/2020 S 5 is a natural satellite of Saturn. Its discovery was announced by Edward Ashton, Brett J. Gladman, Jean-Marc Petit and Mike Alexandersen on May 6, 2023 from observations taken between July 3, 2019 and July 9, 2021.
S/2020 S 5 is about 3 kilometers in diameter, and orbits Saturn at a distance of 18.422 Gm in 933.52 days, at an inclination of 49.41°, orbits in prograde direction and eccentricity of 0.135. S/2020 S 5 belongs to the Inuit group and it may be a Siarnaq fragment that broke off long ago, since it shares the same orbital elements.
The orbit of S/2020 S 5 librates in accordance with the von Zeipel–Lidov–Kozai effect.
References
Inuit group
Irregular satellites
Moons of Saturn
Moons with a prograde orbit
Astronomical objects discovered in 2023
Kozai mechanism | S/2020 S 5 | [
"Astronomy"
] | 191 | [
"Astronomy stubs",
"Planetary science stubs"
] |
74,504,375 | https://en.wikipedia.org/wiki/Keiko%20Hattori | Keiko Hattori is a geochemist and mineralogist. She is Distinguished University Professor of Geochemistry and Mineral Deposits in the Department of Earth and Environmental Sciences at the University of Ottawa.
Hattori is most known for her research on aspects of Earth's atmospheric and mantle evolution, as well as the formation of arc volcanoes and the generation of metal-fertile volcanic arcs. Her application of this knowledge has led to insights regarding the origins and locations of mineral deposits. Specifically, she has conducted research on the transfer of chalcophile elements (copper-like elements) from slabs to arc magmas through mantle wedges, as well as from arc magmas to mineral deposits. Additionally, her work has encompassed exploration geochemistry, where she has investigated the dispersion of metals from buried deposits including platinum and palladium in surface media. She was appointed as the 2022 International Exchange Lecturer of the Society of Economic Geologists (SEG), and has been the recipient of the Island Arc Award and the Takeo Kato Gold Medal.
Hattori is an elected Fellow of the Royal Society of Canada and Mineralogical Society of America.
Education
Hattori was the first female undergraduate student in the Geology Department at the University of Tokyo, which was established in 1877. She completed her master's and PhD in isotope geochemistry there.
Career
Hattori began her academic career as a postdoctoral researcher at the University of Alberta in Edmonton in 1977 and participated in the International Drilling project as a Canadian delegate to study volcanic rocks and thermal alteration in Iceland. In 1980, she moved to the University of Calgary as a Research Associate jointly affiliated with the Department of Physics and the Department of Geology and Geophysics. Three years later, she joined the University of Ottawa as an Assistant Professor and was promoted to Associate Professor in the Department of Geology in 1987.
She was the first female Professor in earth science departments within the national capital region as well as the first female Professor of mineral deposits in Canada. In 1994 she became Full Professor in the Department of Earth and Environmental Sciences at the University of Ottawa. She was awarded the title of Distinguished University Professor in 2023 for her contributions to scientific research and education.
Hattori has held numerous administrative appointments throughout her career. From July 1991 to June 1994, she served as the Director of the Ottawa-Carleton Geoscience Centre. In 2004, she was appointed as the department chair for Earth Sciences at the University of Ottawa, a position she held for four years.
Apart from the administrative work related to universities, she has been engaged in the activities of several scientific organizations including Mineralogical Society of America, Society of Economic Geologists, and Royal Society of Canada. She is Director of Earth, Ocean and Atmosphere Science Division of Royal Society of Canada (2021-2024).
Hattori was an appraiser of graduate-research programs at various Ontario Universities (1999-2002) and geoscience program reviewers of American University of Beirut in Lebanon (2016-17), Western University (2012) and Hiroshima University (2009).
Hattori has been appointed as Visiting Professor at Université de Lyon (1999) and l’Universiteé Grenoble (2016), Visiting Scientist at Japan Marine Science and Technology (2003-2004), Visiting Professor at Nagoya Institute, Guest Research Scientists at Woods Hole Oceanographic Institution (1995-1996), Visiting Research Scientist at Massachusetts Institute of Technology (1989-1990).
Research
Hattori has made contributions to the field of earth sciences, utilizing trace element geochemistry and stable and radiogenic isotopes to understand the earth processes. During the early stages of her career, she focused on studying active volcanoes and associated hydrothermal activity. However, a tragic accident atop a Colombian volcano, resulting in the loss of several colleagues, prompted her to shift her research focus to ancient volcanic terranes in Canada. Over the past 14 years, she has conducted research in various regions of subduction zones worldwide, where oceanic crust subducts and forms arc volcanoes and mountain belts. Her investigations involve examining rocks and collecting samples to analyze the intricate processes of subduction and the subsequent return of materials to the surface through volcanoes. Her research areas have included the Himalayas (Northern Pakistan, Northern India), Italian and French Alps, Turkey, China, Japan, Philippines, Peru, and the Dominican Republic.
Hattori's contributions to the earth sciences primarily center on utilizing the abundance of redox-sensitive elements and their isotopic compositions to interpret processes from the surface to the mantle. Her discoveries include the timing of the abrupt rise in atmospheric oxygen content at around 2.2 billion years ago during Earth's evolution, the definition of osmium isotope evolution in the mantle, the identification of serpentine as the reservoir of water and fluid-mobile elements in the mantle, and the provision of evidence that oxidized mafic magmas bring base metals and sulfur from the mantle to form giant copper deposits that supply many critical metals for society. In addition, her work has contributed to the discovery of such critical metal deposits through the mobility of metals in surface waters.
Earth's surface environmental evolution
Hattori presented evidence in her Nature paper that, resolved the long-standing debate regarding the timing of the change in ancient Earth's surface oxidation. Her findings demonstrated that atmospheric oxygen levels were still low around 2.4 billion years ago, during the early Proterozoic, based on detailed sulfur isotope analysis of sedimentary rocks on the north shore of Lake Huron. In her subsequent work published in Science, she revealed that atmospheric oxygen levels sharply rose within the sedimentary sequence at about 2.3 billion years.
Hattori also highlighted the role of volcanic processes in shaping the surface redox condition, challenging the previously held belief that increased photosynthesis was solely responsible for the oxidation of Earth's surface environment. Subsequent work provided further confirmation of the crystallization of oxidized magmatic sulfates during igneous crystallization, as well as the presence of such sulfate minerals in ancient (2.6 billion years old) igneous rocks.
Mantle evolution
Hattori defined the osmium isotope evolution of Earth's mantle, providing evidence for an accretion of chondritic meteorites after the core-mantle separation.
Prior to Hattori's research, the origin of large nuggets of platinum-group metals in streams was a subject of debate, with some proposing river water formation under a tropical climate and others suggesting mechanical erosion from rocks. However, her research presented evidence supporting their formation in rocks at high temperatures, followed by erosion to streams.
Through Hattori's research, it was also revealed that platinum grains found in streams contain oxygen, which led to initial suggestions of platinum oxide; however, using synchrotron techniques, it was demonstrated that the oxygen is combined with iron, not with platinum.
Roles of serpentinites
Hattori argued that the prevailing view for volcano formation in arcs ic arc formation, that water is released rapidly from subducting slabs when they are metamorphosed to eclogite facies, is inconsistent with geological evidence. Instead, she proposed an alternative mechanism, suggesting that water is continuously released from slabs and stored as serpentinites (hydrated mantle rocks) and stressed that the subsequent dehydration of these serpentinites triggers the formation of arc volcanoes. Her work has established the importance and distribution of serpentinites on the major ocean floors, which control seismic activity and may potentially have played a role in the origin of life on the planet.
Additionally, Hattori's work highlighted that heavy metals and metalloids, such as arsenic and antimony, are generally considered to be concentrated in sulphides, but under sulphur-deficient conditions, these elements behave like normal rock-forming elements.
Oxidation condition of the mantle
Hattori and De Hoog, after considering the debate surrounding the cause of varying oxidation conditions in igneous rocks at shallow crustal levels, documented that highly oxidized conditions of rocks are an intrinsic character of the source magma in the mantle. They emphasized the capability of oxidized magmas to transport large quantities of sulfur and metals as well.
In her 1995 work, Hattori provided the initial documentation of oxidized arsenic in the overall reduced mantle, as arsenic is present by replacing Si. One of her PhD students, Jian Wangm, evaluated the redox state of mantle rocks and discovered that carbon is the primary control for the oxidation conditions of the mantle in subduction zones.
Oxidized mafic magmas for the formation of base metal deposits
Hattori's research interest has also extended to porphyry-type deposits, which supply critical metals such as copper, molybdenum, and gold. Through her research, she presented evidence supporting the notion that sulfur and metals have their origin in the mantle, and proposed that they were extracted and transported by mafic magmas from the mantle to shallow crustal levels. This proposal was based on her earlier work on Pinatubo eruption products, where metals and sulphur are released from mafic magmas during their ascent and incorporated into overlying erupted felsic magmas. Furthermore, Cees-Jan DeHoog, her post-doctoral research fellow, provided evidence that oxidized magmas are capable to transport metals and sulphur from deep in the mantle to shallow levels of crust.
Dispersion of metals in surface media
Hattori developed analytical methods that demonstrated the high mobility of palladium as soluble neutral to anionic complexes in surface waters. This behavior allows the metal to disperse widely from its sources, and to become incorporated into plants and organic-rich soil. Her research findings have been presented at various industry-oriented workshops, including short courses associated with the International Platinum Conference in Oulu, Finland, and the Prospectors and Developers Association meeting in Toronto. In addition, her research provided a contrasting perspective to the previously assumed origin of metals in peat from the Hudson Bay Lowland. While it was previously assumed that the metals in peat originated from industrial activity far south of the northern region, she demonstrated that the compositions of ombrotrophic peat are strongly influenced by the underlying rocks, even those located as deep as 20 metres below the surface. This observation further highlighted that the composition of peat may serve as a useful indicator to locate concealed deposits, including kimberlites, which are host to diamonds.
Hattori also examined sturdy minerals that can be dispersed by streams and glaciers to evaluate their usefulness in finding mineral deposits.
Awards and honors
2011 – Elected Fellow, Royal Society of Canada
2012 – Elected Fellow, Mineralogical Society of America
2013 – Island Arc Award, the Geological Society of Japan
2022 – Takeo Kato Gold Medal, the Society of Resource Geology
2022 – International Exchange Lecturer, Society of Economic Geologists
2023 – Distinguished University Professor, University of Ottawa
2024 - Duncan R. Derry Medal from Geological Association of Canada
Selected articles
Hattori, K. (1993). High-sulfur magma, a product of fluid discharge from underlying mafic magma: evidence from Mount Pinatubo, Philippines. Geology, 21(12), 1083–1086.
Hattori, K. H., & Keith, J. D. (2001). Contribution of mafic melt to porphyry copper mineralization: evidence from Mount Pinatubo, Philippines, and Bingham Canyon, Utah, USA. Mineralium Deposita, 36, 799–806.
Hattori, K. H., & Guillot, S. (2003, April). Volcanic fronts as a consequence of serpentinite dehydration in the mantle wedge. In EGS-AGU-EUG Joint Assembly.
Takahashi, Y., Minamikawa, R., Hattori, K. H., Kurishima, K., Kihou, N., & Yuita, K. (2004). Arsenic behavior in paddy fields during the cycle of flooded and non-flooded periods. Environmental Science & Technology, 38(4), 1038–1044.
Guillot, S., Hattori, K., 2013. Serpentinites: Essential roles in geodynamics, arc volcanism, sustainable development, and the origin of life. Elements, 9 (2),. 95-98. Doi: 10.2113/gselements.9.2.25
Hattori, K. H., & Guillot, S. (2003l). Volcanic fronts as a consequence of serpentinite dehydration in the mantle wedge.Geology, 31 (6), 525-528.
Hattori, K., Takahashi, Y., Guillot, S., & Johanson, B. (2005). Occurrence of arsenic (V) in forearc mantle serpentinites based on X-ray absorption spectroscopy study. Geochimica et Cosmochimica Acta, 69(23), 5585–5596.
Pagé, L., & Hattori, K. (2017). Tracing halogen and B cycling in subduction zones based on obducted, subducted and forearc serpentinites of the Dominican Republic. Scientific Reports, 7(1), 17776.
References
Geochemists
Mineralogists
Geochemistry
University of Tokyo alumni
Living people
Year of birth missing (living people)
Academic staff of the University of Ottawa
Fellows of the Royal Society of Canada
Academic staff of the University of Calgary
Fellows of the Mineralogical Society of America | Keiko Hattori | [
"Chemistry"
] | 2,746 | [
"Geochemists",
"nan"
] |
67,330,570 | https://en.wikipedia.org/wiki/Kansri%20Boonpragob | Kansri Boonpragob () is a lichenologist and climatologist from Thailand, who leads the Lichen Research Unit at Ramkhamhaeng University.
Career
Boonpragob is Head of the Lichen Research Unit and Assistant Professor of Biological Science at Ramkhamhaeng University. She has published widely, including several books and dozens of articles. She also has a PhD in Ecology. During 2007 she held a post as Vice-Chair of the Intergovernmental Panel on Climate Change's Working Group I. Boonpragob's research has demonstrated that there are already severe economic impacts on Thailand due to the ongoing climate crisis. Much of this impact is on coastal regions, where livelihoods as well as species, are at risk. She is a member of the Graphidaceae Project, administered by the Field Museum. In 2008 she organized the first workshop on thelotremoid Graphidaceae in Thailand. She is a member of the Editorial Board for the Journal of Tropical Forest Research.
The lichen Ocellularia kansriae is named after Boonpragob, who collected specimens from Eastern Thailand.
See also
:Category:Taxa named by Kansri Boonpragob
References
Kansri Boonpragob
Kansri Boonpragob
Kansri Boonpragob
Ecologists
Women ecologists
Year of birth missing (living people)
Living people
Kansri Boonpragob
Kansri Boonpragob
Kansri Boonpragob
Kansri Boonpragob | Kansri Boonpragob | [
"Environmental_science"
] | 314 | [
"Ecologists",
"Environmental scientists"
] |
67,331,081 | https://en.wikipedia.org/wiki/Helga%20Weisz | Helga Weisz (born 1961 in Villach) is an Austrian industrial ecologist, climate scientist, and professor of industrial ecology and climate change at the Institute for Social Sciences at the Humboldt University of Berlin. She heads the FutureLab "Social Metabolism & Impacts" at the Potsdam Institute for Climate Impact Research (PIK).
Life
Weisz graduated from the University of Vienna with a master's degree in microbiology in 1995. She received her doctorate in cultural studies from the HU Berlin in 2002. In 2006, she graduated from Alpen-Adria University with a Venia Docendi (Habilitation) in socioecology. From 1991 to 2009 she held various scientific roles at the Faculty for Interdisciplinary Research and Continuing Education in Vienna. She has been a guest professor at the University of St. Gallen and Yale School of Forestry & Environmental Studies. From 2009 to 2012 she was a co-chair of PIK research domain II: Climate impacts & vulnerability, and from 2012 to 2018 of the research domain for interdisciplinary concepts and methods.
Work
Weisz's research focuses on the socially responsible production of raw materials and energy, the conversion of raw materials into goods and services, and their use and disposal in the environment as waste, emissions and heat, which together constitute social metabolism.
Weisz is active in the public debate about means to address the climate crisis. When she published her study on reducing urban greenhouse gas footprints in 2017, she said: "Cities around the world must be encouraged and enabled to monitor their entire emission spectrum—local and upstream emissions. Only then can the necessary and ambitious plans of many cities to comply with the 2-degree limit be realized."
Selected publications
With Peter-Paul Pichler, Timm Zwickel, Abel Chavez, Tino Kretschmer, Jessica Seddon: Reducing urban greenhouse gas footprints. In: Scientific Reports, 7, 2017, p. 14659.
With Fridolin Krausmann, Christof Amann, Nina Eisenmenger, Karl-Heinz Erb, Klaus Hubacek, Marina Fischer-Kowalski: The physical economy of the European Union: Cross-country comparison and determinants of material consumption. In: Ecological Economics, 58 (4), pp. 676–698.
With Sangwon Suh, T. E. Graedel: Industrial Ecology: The role of manufactured capital in sustainability. In: Proceedings of the National Academy of Sciences, 112(20), 2015, pp. 6260–6264.
References
1961 births
University of Vienna alumni
Academic staff of the Humboldt University of Berlin
Ecologists
Austrian climatologists
21st-century Austrian scientists
Austrian women scientists
University of Klagenfurt alumni
Yale University faculty
Academic staff of the University of St. Gallen
Living people | Helga Weisz | [
"Environmental_science"
] | 565 | [
"Ecologists",
"Environmental scientists"
] |
67,331,224 | https://en.wikipedia.org/wiki/Anderson%27s%20bridge | In electronics, Anderson's bridge is a bridge circuit used to measure the self-inductance of the coil. It enables measurement of inductance by utilizing other circuit components like resistors and capacitors.
Anderson's bridge was invented by Alexander Anderson in 1891. He modified Maxwell's inductance capacitance bridge so that it gives very accurate measurement of self-inductance.
Balance conditions
The balance conditions for Anderson's bridge or, equivalently the values of the self-inductance and resistance of the given coil can be found using basic circuit analysis techniques such as KCL, KVL and using phasors.
Consider the circuit diagram of Anderson's bridge in the given figure. Let L1 be the self-inductance and R1 be the electrical resistance of the coil under consideration. Since the voltmeter is ideally assumed to have nearly infinite impedance, the currents in branches ab and bc and those in the branches de and ec are taken to be equal. Applying Kirchhoff's current law at node d, it can be shown that-
Since the analysis is being made under the balanced condition of the bridge, it can be said that the voltage drop across the voltmeter is essentially zero. On applying Kirchhoff's voltage law to the appropriate loops(in the anti-clockwise direction), the following relations hold-
On solving these sets of equations, one can finally obtain the self-inductance and resistance of the coil as-
Advantages
The Anderson's bridge can also be used the other way round- that is, it can be used to measure the capacitance of an unknown capacitor using an inductor coil whose self-inductance and electrical resistance have been pre-determined to a high degree of precision. An interesting point to note is the fact that the measured self-inductance of the coil does not change even on taking dielectric loss within the capacitor into account. Another advantage of using this modified bridge is that unlike the variable capacitor used in Maxwell bridge, it makes use of a fixed capacitor which is relatively quite cheaper.
Disadvantages
One of the obvious difficulties associated with Anderson's bridge are the relatively complex balance equation calculations compared to the Maxwell bridge. The circuit connections and computations are similarly more cumbersome in comparison to the Maxwell bridge.
References
Measuring instruments
Bridge circuits
Analog circuits
Irish inventions
Impedance measurements | Anderson's bridge | [
"Physics",
"Technology",
"Engineering"
] | 499 | [
"Physical quantities",
"Analog circuits",
"Measuring instruments",
"Electronic engineering",
"Impedance measurements",
"Electrical resistance and conductance"
] |
67,331,324 | https://en.wikipedia.org/wiki/Zoia%20Duriagina | Zoia Antonivna Duriagina (; born 8 June 1950 in Lviv) is a Ukrainian scientist, materials engineer, doctor of sciences, professor, full member of the Academy of Sciences of Higher Education of Ukraine, a member of Shevchenko Scientific Society, and the head of the Department of Applied Materials Science and Materials Processing at the Institute of Engineering Mechanics and Transport, which is part of Lviv Polytechnic National University.
She has an entry in the Encyclopedia of Modern Ukraine.
Biography
Zoia Duriagina was born on 8 June 1950 in the Lviv. After graduating from Lviv Secondary School № 6 in 1967, she entered the Lviv Polytechnic Institute, graduating in 1972 with a degree in metallurgical engineering in the specialty "Physics of Metals." In the same year she entered graduate school at the Department of Physics of Metals and Materials Science. After successfully graduating from graduate school from 1975 to 2013, she worked at Lviv Polytechnic as a junior researcher at the research laboratory, assistant, senior lecturer, associate professor, professor (2006) of the Department of Engineering Materials Science and Applied Physics. Since 2012 — Head of the Department of Applied Materials Science and Materials Processing, National University "Lviv Polytechnic." Since 2015, Professor ZA Duryagina He also teaches at the Department of Engineering and Technical Sciences of the John Paul II Catholic University in Lublin (Poland).
In 1978, she defended her dissertation for the degree of Candidate of Technical Sciences—"The influence of the structure of stainless steels on corrosion resistance and the tendency to cracking in the conditions of sulfur smelting."
In 2005, she defended her dissertation for the degree of Doctor of Technical Sciences—"Regularities of creating barrier layers with a controlled structural-phase state to optimize the properties of structural materials of power equipment."
She has published 275 scientific papers in the fields of metallurgy, materials science, solid state physics and surface engineering, the lion's share of which are articles in professional journals, including 55 articles in journals indexed in Scopus and Web of Science databases.
See also
Lviv Polytechnic National University
Shevchenko Scientific Society
References
Sources
Б.С. Рильніков, С.Г. Швачко. Кафедра інженерного матеріалознавства та прикладної фізики: До 135-річчя заснування. — Львів: Видавництво Національного університету "Львівська політехніка", 2007. — 108 с.
Дурягіна Зоя Антонівна (вікі: Електронна енциклопедія «Львівської політехніки»)
External links
1950 births
Lviv Polytechnic alumni
20th-century Ukrainian women scientists
Engineers from Lviv
20th-century Ukrainian engineers
20th-century women engineers
21st-century Ukrainian engineers
21st-century women engineers
Living people
Ukrainian women engineers
21st-century Ukrainian women scientists
Women materials scientists and engineers | Zoia Duriagina | [
"Materials_science",
"Technology"
] | 712 | [
"Women materials scientists and engineers",
"Materials scientists and engineers",
"Women in science and technology"
] |
67,332,262 | https://en.wikipedia.org/wiki/Aida%20El-Khadra | Aida Xenia El-Khadra is a particle physicist who is a professor of high energy physics at the University of Illinois at Urbana–Champaign. She is the co-chair of the Muon g-2 Theory Initiative, which reported hints at new physics in the Standard Model in 2021. She is a fellow of the American Physical Society and the Alfred P. Sloan Foundation.
Early life and education
El-Khadra was an undergraduate student at the Free University of Berlin, where she earned a master's degree in physics. She moved to the University of California, Los Angeles for her doctoral research, where she studied semi-leptonic decays. El-Khadra was a postdoctoral researcher at the Brookhaven National Laboratory, Fermilab, and the Ohio State University.
Research and Pathways
In 1995, El-Khadra joined the faculty at the University of Illinois at Urbana–Champaign, where she was promoted to professor in 2008. Her research makes use of quantum chromodynamics to understand processes in flavor physics. She spent 1998 as a Fellow at the Center for Advanced Study, where she developed and tested new lattice actions. El-Khadra directs the Fermilab Lattice collaboration and was named a distinguished scholar at Fermilab in 2016.
El-Khadra oversaw the theoretical aspects of the Muon g-2 experiments. The collaboration measured the magnetic moment of the muon with unparalleled precision. El-Khadra has been involved with several theoretical attempts to predict the anomalous magnetic moment based on the Standard Model. In 2021, the experimental component of the collaboration reported a magnetic moment that was considerably larger than the value predicted by the Standard Model. These finding hints at new particles or forces in the Standard Model.
Achievements
El-Khadra was elected fellow of the American Physical Society in 2011 "for contributions to lattice QCD and flavor physics including pioneering studies of heavy quarks on the lattice, semi-leptonic and leptonic heavy-light meson decays, the strong coupling constant, and quark masses". She was named to the 2021 class of fellows of the American Association for the Advancement of Science. In 2022 she was awarded a Simons Fellowship.
Selected publications
References
Living people
Year of birth missing (living people)
Free University of Berlin alumni
University of Illinois Urbana-Champaign faculty
University of California, Los Angeles alumni
Particle physicists
Brookhaven National Laboratory staff
Ohio State University staff
Fellows of the American Physical Society
Fellows of the American Association for the Advancement of Science
21st-century women physicists | Aida El-Khadra | [
"Physics"
] | 522 | [
"Particle physicists",
"Particle physics"
] |
67,333,282 | https://en.wikipedia.org/wiki/Foltx | Foltx is a vitamin supplement containing a combination of vitamin B6 (pyridoxine), vitamin B12 (cyanocobalamin), and folic acid (folacin). It may be used to treat hyperhomocysteinemia, a medical condition.
References
B vitamins | Foltx | [
"Chemistry"
] | 66 | [
"Pharmacology",
"Pharmacology stubs",
"Medicinal chemistry stubs"
] |
67,333,772 | https://en.wikipedia.org/wiki/Orphan%20wells | Orphan, orphaned, or abandoned wells are oil or gas wells that have been abandoned by fossil fuel extraction industries. These wells may have been deactivated because had become uneconomic, failure to transfer ownerships (especially at bankruptcy of companies), or neglect, and thus no longer have legal owners responsible for their care. Decommissioning wells effectively can be expensive, costing several thousands of dollars for a shallow land well to millions of dollars for an offshore one. Thus the burden may fall on government agencies or surface landowners when a business entity can no longer be held responsible.
Orphan wells are a potent contributor of greenhouse gas emissions, such as methane emissions, contributing to climate change. Much of this leakage can be attributed to failure to have them plugged properly or leaking plugs. A 2020 estimate of abandoned wells in the United States was that methane emissions released from abandoned wells produced greenhouse gas impacts equivalent to three weeks of US oil consumption each year. The scale of leaking abandoned wells is well understood in the US and Canada because of public data and regulation; however, a Reuters investigation in 2020 could not find good estimates for Russia, Saudi Arabia and China—the next biggest oil and gas producers. However, they estimate there are 29 million abandoned wells internationally.
Abandoned wells have the potential to contaminate land, air and water, potentially harming ecosystems, wildlife, livestock, and humans. For example, many wells in the United States are situated on farmland, and if not maintained could contaminate soil and groundwater with toxic contaminants.
Economic limits
A well is said to reach an "economic limit" when revenue from production does not cover the operating expenses, including taxes. If the economic limit is increased, the useful life of the well is shortened and proven oil reserves are lost. Conversely, when the financial limit is lowered, the life of the well is lengthened. When the economic limit is reached, the well becomes a liability if not abandoned.
At the economic limit, a significant amount of unrecoverable oil is often left in the reservoir. It might be tempting to defer physical abandonment for an extended period, hoping that the oil price will increase or that new supplemental recovery techniques will be perfected. In these cases, wells are merely shut in, or temporary plugs may be placed downhole. There are thousands of "temporarily abandoned" wells throughout North America, waiting to see what the market will do before permanent abandonment. However, lease provisions and governmental regulations often require quick abandonment; liability and tax concerns also may favor abandonment.
Theoretically, an abandoned well can be re-entered to restore production (or converted to injection service for supplemental recovery or downhole hydrocarbon storage), but reentry is often difficult mechanically and expensive. Traditionally elastomer and cement plugs have been used with varying degrees of success and reliability. Over time, they may deteriorate, particularly in corrosive environments, due to the materials from which they are manufactured. New tools have been developed that make re-entry easier; these tools offer higher expansion ratios than conventional bridge plugs and higher differential pressure ratings than inflatable packers, all while providing a V0-rated, gas-tight seal that cement cannot provide.
Reclaim and reuse
Some abandoned wells are subsequently plugged and the site is remediated; however, the cost of such efforts can be in the millions of dollars. In this process, tubing is removed from the well, and sections of wellbore are filled with cement to isolate the flow path between gas and water zones from each other, as well as from the surface. The wellhead is cut off, a cap is welded in place and then the stub is buried as the land contours are restored.
Plugging
The primary method of plugging wells is through elastomer and cement plugs. Government-led campaigns to plug wells are expensive but often facilitated by oil and gas taxes, bonds, or other fees applied to production. Environmental non-profit organizations, such as the Well Done Foundation, also carry out well-plugging projects and develop programs alongside government entities.
Plug bonds
Oil and gas companies on public land in the United States must post financial assurance to cover the cost of plugging wells if they go bankrupt or cannot plug the well themselves. The current financial assurance requirement, which has been in place for 60 years, is $10,000 per well. This is significantly less than the cost of plugging a well, ranging as high as $400,000. Thus many federal oil and gas leases have a bond that cannot cover the cost of cleanup.
New rules related to the Infrastructure Investment and Jobs Act will increase the financial assurance requirement to a minimum of $150,000 per well. This will help ensure that oil and gas companies have the financial resources to plug wells if they can no longer do so themselves.
CO2 injection
Unused wells, especially from natural gas might be used for carbon capture or storage. However, if not sealed properly, or the storage site is not sufficiently sealed, there is a possibility of leakage.
Geothermal generation
A 2014 study in China evaluated the use of abandoned wells for geothermal power generation. A similar study followed in 2019 for natural gas wells.
Environmental impacts
Hydraulic fracturing
Hydraulic fracturing, also known as fracture treating or fracking, is the process of fracturing bedrock with pressurized liquids. This creates cracks in rock formations that allow natural gas, petroleum, and brine to flow more effortlessly. When hydraulic fracturing is done in the vicinity of an orphaned well it can cause breaches of poorly sealed or unsealed abandoned wells that possibly can contaminate local ecosystems. These orphaned wells can allow gas and oil to contaminate groundwater due to improper sealing.
By context
Alberta, Canada
United States
Notes
References
Oil wells | Orphan wells | [
"Chemistry"
] | 1,178 | [
"Petroleum technology",
"Oil wells"
] |
67,335,358 | https://en.wikipedia.org/wiki/Rhodium%28III%29%20perchlorate | Rhodium(III) perchlorate refers to the inorganic compound with the formula Rh(H2O)6(ClO4)3. It is a hygroscopic yellow solid. It is the perchlorate salt of the tricationic aquo complex [Rh(H2O)6]3+. The compound is prepared by treating hydrated rhodium(III) chloride and perchloric acid at elevated temperatures:
[Rh(H2O)6]Cl3 + 3 HClO4 → [Rh(H2O)6](ClO4)3 + 3 HCl
The reaction of rhodium(III) hydroxide with concentrated perchloric acid also produce rhodium(III) perchlorate.
Rh(OH)3 + 3 HClO4 → Rh(ClO4)3 + 3 H2O
References
Rhodium(III) compounds
Perchlorates | Rhodium(III) perchlorate | [
"Chemistry"
] | 201 | [
"Salts",
"Inorganic compounds",
"Perchlorates",
"Inorganic compound stubs"
] |
67,335,456 | https://en.wikipedia.org/wiki/Rhodium%28III%29%20sulfate | Rhodium(III) sulfate refers to inorganic compounds of the formula Rh2(SO4)3. It is a red crystalline solid.
Preparation
The first attempts to produce rhodium(III) sulfate was in 1929 with the reaction of rhodium(III) hydroxide and sulfuric acid . They reported that there were two different types of hydrates, the yellow colored tetradecahydrate and the red colored tetrahydrate. This not conformed due to the lack of structural proof. Then further investigations has been done on the hexahydrate and the tetradecahydrate with x-ray diffraction. The first structural elucidations have been done at 2009 which conformed the existence of the chemical.
Then at 2016, a much efficient production method was reported. This method used rhodium metal and sulfuric acid to make the rhodium(III) sulfate. The two compounds were heated together at 400°C to make the anhydrous compound. It was shown that if it was heated at 475°C instead, it would make the dihydrate.
References
Rhodium(III) compounds
Sulfates | Rhodium(III) sulfate | [
"Chemistry"
] | 246 | [
"Sulfates",
"Inorganic compounds",
"Inorganic compound stubs",
"Salts"
] |
67,337,770 | https://en.wikipedia.org/wiki/Hydroxymethylation | Hydroxymethylation is a chemical reaction that installs the CH2OH group. The transformation can be implemented in many ways and applies to both industrial and biochemical processes.
Hydroxymethylation with formaldehyde
A common method for hydroxymethylation involves the reaction of formaldehyde with active C-H and N-H bonds:
R3C-H + CH2O → R3C-CH2OH
R2N-H + CH2O → R2N-CH2OH
A typical active C-H bond is provided by a terminal acetylene or the alpha protons of an aldehyde. In industry, hydroxymethylation of acetaldehyde with formaldehyde is used in the production of pentaerythritol:
P-H bonds are also prone to reaction with formaldehyde. Tetrakis(hydroxymethyl)phosphonium chloride ([P(CH2OH)4]Cl) is produced in this way from phosphine (PH3).
Hydroxymethylation in demethylation
5-Methylcytosine is a common epigenetic marker. The methyl group is modified by oxidation of the methyl group in a process called hydroxymethylation:
RCH3 + O → RCH2OH
This oxidation is thought to be a prelude to removal, regenerating cytosine.
Representative reactions
A two-step hydroxymethylation of aldehydes involves methylenation followed by hydroboration-oxidation:
RCHO + Ph3P=CH2 → RCH=CH2 + Ph3PO
RCH=CH2 + R2BH → RCH2-CH2BR2
RCH2-CH2BR2 + H2O2 → RCH2-CH2OH + "HOBR2"
Silylmethyl Grignard reagents are nucleophilic reagents for hydroxymethylation of ketones:
R2C=O + ClMgCH2SiR'3 → R2C(OMgCl)CH2SiR'3
R2C(OMgCl)CH2SiR'3 + H2O + H2O2 → R2C(OH)CH2OH + "HOSiR'3"
Reactions of hydroxymethylated compounds
A common reaction of hydroxymethylated compounds is further reaction with a second equivalent of an active X-H bond:
hydroxymethylation: X-H + CH2O → X-CH2OH
crosslinking: X-H + X-CH2OH → X-CH2-X + H2O
This pattern is illustrated by the use of formaldehyde in the production various polymers and resins from phenol-formaldehyde condensations (Bakelite, Novolak, and calixarenes). Similar crosslinking occurs in urea-formaldehyde resins.
The hydroxymethylation of N-H and P-H bonds can often be reversed by base. This reaction is illustrated by the preparation of tris(hydroxymethyl)phosphine:
[P(CH2OH)4]Cl + NaOH → P(CH2OH)3 + H2O + H2C=O + NaCl
When conducted in the presence of chlorinating agents, hydroxymethylation leads to chloromethylation as illustrated by the Blanc chloromethylation.
Related
Hydroxyethylation involves the installation of the CH2CH2OH group, as practiced in ethoxylation.
Aminomethylation is often effected with Eschenmoser's salt, [(CH3)2NCH2]OTf
References
Carbon-carbon bond forming reactions | Hydroxymethylation | [
"Chemistry"
] | 786 | [
"Carbon-carbon bond forming reactions",
"Organic reactions"
] |
67,338,884 | https://en.wikipedia.org/wiki/Bromine%20cycle | The bromine cycle is a biogeochemical cycle of bromine through the atmosphere, biosphere, and hydrosphere.
Sources
Natural sources
Bromine is present naturally as bromide salts in evaporite deposits. Bromine is also present in soils and in marine algae that synthesize organic bromine compounds. Other natural sources of bromine come from polar regions, salt lakes, and volcanoes.
The primary natural source of bromine to the atmosphere is sea spray aerosols. Smaller fluxes originate from volcanic emissions and biomass burning. The primary atmospheric sinks are sea spray deposition and photochemical reactions, which release gaseous bromine.
Anthropogenic sources
Bromine is used in flame retardants, pesticides, lighter fuel, antiknocking agents, and for water purification. The organic form of this element is used as flame retardants commercially and in pesticides. These chemicals have led to an increase in the depletion of the stratospheric ozone layer. Some countries use bromine to treat drinking water, similar to chlorination. Bromine is also present as impurities emitted from cooling towers.
Reactions with ozone
Winter sea ice is a significant atmospheric contribution of bromine. Organic bromine gases such as CH3Br, CH2Br2, CH2IBr are emitted by microorganisms in sea ice and snow at ten-fold higher rates than from other environments. In polar areas, decreasing sea ice releases bromine and at the Arctic and Antarctic boundary layer, bromine is released in the spring when the ice melts.
Inorganic bromine is found in the atmosphere and is quickly cycled between its gas and its particulate phase. Bromine gas (Br2) undergoes an autocatalytic cycle known as the 'bromine explosion', which occurs in the ocean and salt lakes such as the Dead Sea, where a high quantity of salts are exposed to the atmosphere. Bromine contributes to 5-15% of tropospheric ozone layer losses.
References
Biogeochemistry
Bromine | Bromine cycle | [
"Chemistry",
"Environmental_science"
] | 421 | [
"Chemical oceanography",
"Biogeochemistry",
"Environmental chemistry"
] |
67,339,218 | https://en.wikipedia.org/wiki/Serazapine | Serazapine (developmental code name CGS-15040A), or serazepine, is a serotonin 5-HT2 receptor antagonist that was investigated as a potential treatment for generalized anxiety disorder in the 1990s. In humans, serazapine was well tolerated at doses of 10 to 40 mg and was found to be superior to placebo for reducing anxiety symptoms as indicated by HAM-A scores. However, clinical development was discontinued.
References
5-HT2 antagonists
Abandoned drugs
Anxiolytics
Heterocyclic compounds with 5 rings
Nitrogen heterocycles
Methyl esters | Serazapine | [
"Chemistry"
] | 125 | [
"Drug safety",
"Abandoned drugs"
] |
67,339,350 | https://en.wikipedia.org/wiki/Francium%20hydroxide | Francium hydroxide is a hypothetical inorganic compound with a chemical formula . It is a hydroxide of francium.
It probably can be produced by reacting francium metal with water:
This reaction might be explosive, because this reaction is probably very exothermic, because of which water could suddenly start boiling violently, producing hot water vapor, and very flammable hydrogen gas is produced in the reaction as well, and hydrogen could ignite, causing fire and explosion. However this is all guesswork, as a visible quantity of francium has never been made.
Francium hydroxide's alkalinity is predicted to be stronger than caesium hydroxide.
References
Francium compounds
Hydroxides
Hypothetical chemical compounds | Francium hydroxide | [
"Chemistry"
] | 152 | [
"Theoretical chemistry stubs",
"Hydroxides",
"Hypotheses in chemistry",
"Theoretical chemistry",
"Hypothetical chemical compounds",
"Bases (chemistry)"
] |
67,339,846 | https://en.wikipedia.org/wiki/Patricia%20E.%20Molina | Patricia Molina is the Richard Ashman, PhD Professor and Department Head of Physiology and Director of the Alcohol and Drug Abuse Center of Excellence (ADACE) at Louisiana State University Health Sciences Center New Orleans. In 2015, she was the 88th President of the American Physiological Society, and is the author of the Lange monographic series Endocrine Physiology.
Life
Molina graduated from the Universidad Francisco Marroquín, and from Louisiana State University Health Sciences Center New Orleans with a PhD in physiology.
She was assistant professor of surgery and physiology at the Stony Brook University, director of surgical research at North Shore University Hospital, and guest scientist at Brookhaven National Laboratory prior to joining the Department of Physiology at Louisiana State University Health Sciences Center New Orleans as an associate professor in 1999.
In 2008, she was named the Richard Ashman, PhD Professor (endowed chair) and Department Head of Physiology and was appointed as director of the Alcohol and Drug Abuse Center of Excellence.
Molina is principal investigator and director of the National Institutes of Health-funded Comprehensive Alcohol-HIV/AIDS Research Center, Biomedical Research Training Program, and Medical Student Alcohol Research Internship Program.
In addition to being the first Hispanic woman to be chair of a department of physiology, Molina has served in a number of leadership roles in her discipline. In 2015, she was the first Hispanic woman president of the American Physiological Society. In 2019, she was president of the Association of Chairs of Department of Physiology, and in 2020-2021 served as president of the Research Society on Alcoholism.
Molina's research focuses on the impact of unhealthy alcohol use on risk of behavioral and metabolic comorbidities associated with HIV/AIDS. Her research is currently funded by the National Institute on Alcohol Abuse and Alcoholism of the National Institutes of Health.
References
External links
Year of birth missing (living people)
Living people
Louisiana State University alumni
Women physiologists
Stony Brook University faculty
21st-century women scientists
Universidad Francisco Marroquín alumni
Women in medicine
Physiology
Physiologists | Patricia E. Molina | [
"Biology"
] | 403 | [
"Physiology"
] |
67,341,981 | https://en.wikipedia.org/wiki/Methylenation | In organic chemistry, methylenation is a chemical reaction that inserts a methylene () group into a chemical compound:
In a related sense, it also describes a process in which a divalent group of a starting material is removed and replaced with a terminal CH2 group:
Methylenation in this context is also known as methenylation. Most commonly, E is an oxygen atom, so that the reaction results in terminal alkenes from aldehydes and ketones, or more rarely, enol ethers from esters or enamines from amides.
Methods
Methylene Insertion into Alkanes
Singlet methylene (1[:CH2]), produced from photolysis of diazomethane under ultraviolet irradiation, methylenates hydrocarbons. Arenes and olefins undergo methylenation to give cyclopropanated products. In the case of arenes, the cyclopropanation product undergoes further electrocyclic ring opening to give cycloheptatriene products (Buchner ring expansion). Alkenes undergo both C=C methylenation and C–H methylenation insertion to give a mixture of cyclopropanation and homologation products.
Reflecting the exceptionally high reactivity of singlet methylene, normally unreactive alkanes undergo methylenation to give homologation products, even at –75 °C.
Photolysis of a solution of diazomethane in n-pentane gives a mixture of hexanes and higher homologues. At –75 °C, the product ratio is 48:35:17 mixture of n-hexane, 2-methylpentane, and 3-methylpentane. The ratio is remarkably close to the statistical product ratio of 6:4:2 (~50:33:17) based on the number of available C–H bonds at each position that could undergo methylene insertion. As a result, Doering and coworkers concluded:Methylene must be classed as the most indiscriminate reagent known in organic chemistry.
Methylene-for-oxo reactions
A common method for methylenation involves the Wittig reaction using methylenetriphenylphosphorane with an aldehyde (Ph = phenyl, ):
RCHO + Ph3P=CH2 -> RCH=CH2 + Ph3PO
A related reaction can be accomplished with Tebbe's reagent, which is sufficiently versatile to allow methylenation of esters:
RCO2R' + Cp2Ti(Cl)CH2AlMe2 -> RC(OR')=CH2 + Cp2TiOAlMe2Cl
Other less well-defined titanium reagents, e.g., Lombardo's reagent, effect similar transformations.
Carbanions derived from methylsulfones have also been employed, equivalently to the Wittig reaction.
Methylenation adjacent to carbonyl groups
Ketones and esters can be methylenated at the α position to give α,β-unsaturated carbonyl products containing an additional terminal CH2 group in a three-step process known as the Eschenmoser methylenation. An enolate is generated by deprotonation of the α-C–H bond using a hindered lithium amide (LiNR2) base (e.g., LDA, LHMDS). Subsequently, the enolate is reacted with Eschenmoser's salt ([Me2N=CH2]+I–) to give a β-dimethylamino carbonyl compound (Mannich base). The Mannich base is then subjected to methylation or N-oxidation to give a trimethylammonium salt or amine N-oxide, which is then subjected to Hofmann elimination or Cope elimination, respectively to give the α-methylene carbonyl compound. If the Hofmann elimination is used, the process can be represented as follows:
RC(=O)CH2R' -> RC(=O) CH(CH2NMe2)R' -> [RC(=O) CH(CH2NMe3)R']+I- -> RC(=O) C(=CH2)(R')
Other approaches
Ethenolysis is a method for methylenation of internal alkene as illustrated by the following example:
In principle, the addition of across a double bond could be classified as a methylenation, but such transformations are commonly described as cyclopropanations.
References
Carbon-carbon bond forming reactions | Methylenation | [
"Chemistry"
] | 970 | [
"Carbon-carbon bond forming reactions",
"Organic reactions"
] |
67,342,560 | https://en.wikipedia.org/wiki/John%20Robert%20Suman | John Robert Suman (April 9, 1890, Daleville, Indiana – January 5, 1972, Houston, Texas) was a geologist, petroleum engineer, and business executive.
Biography
As a child, John R. Suman emigrated with his family from Indiana to Southern California. After completing high school he matriculated at the University of Southern California. He transferred to the University of California, Berkeley, where he graduated from the Mining College with honors in 1912. After graduation he worked as an assistant geologist for the Houston-based Rio Bravo Oil Company, a Southern Pacific Railroad Company subsidiary that supplied oil to the railroad company and administered the land it owned. He worked under Dr. Edwin T. Dumble, a former director of the Texas Geological Survey, and William Kennedy, who in the early 1890s was the primary petroleum geologist working on the Texas Coastal Plain. After one year working for Rio Bravo, Suman was promoted of chief engineer. In 1917 he resigned from Rio Bravo and joined Roxana Petroleum Company, a subsidiary of Royal Dutch Shell. For two years he worked for Roxana Petroleum as technical superintendent for the company's operations in Texas and Louisiana. In 1919 he rejoined Rio Bravo as an assistant to the vice-president. He was promoted to general manager in 1925 and resigned from Rio Bravo in 1927. In 1923 he, along with several colleagues, formed the Houston Geological Society and served for two years as the Society's first president.
In 1927 John Suman began work for Humble Oil and Refining Company, chief operating subsidiary of Standard Oil Company of New Jersey. In 1933 he was appointed Humble Oil's vice president in charge of production at Houston. In 1933, near Conroe, Texas, a blowout occurred in an oil well, resulting in an uncontrolled flow of about 7,000 barrels per day. Suman pioneered the use of a directional well drilled into the producing sand in order to flood the sand with water and with drilling mud to stop the uncontrolled flow. In the 1930s and early 1940s he was instrumental in Humble Oil's development into the American Southwest's leading petroleum producer. From 1945 until his retirement in 1955 he was a vice-president and member of the board of directors of Standard Oil Company of New Jersey. In 1941 he was the president of American Institute of Mining, Metallurgical, and Petroleum Engineers (AIME). In 1943 he was awarded AIME's Anthony F. Lucas Gold Medal. In 1958 he won the John Fritz Medal.
On December 16, 1912, he married Beatrice Mary Mowers (1888–1976). They had two sons, John Robert Suman Jr. (1916–2004) and Richard Harlan Suman (1917–1999). Both sons had careers in the petroleum industry.
Selected publications
References
1890 births
1972 deaths
People from Delaware County, Indiana
University of California, Berkeley alumni
20th-century American businesspeople
20th-century American engineers
American businesspeople in the oil industry
Petroleum engineers
Standard Oil | John Robert Suman | [
"Engineering"
] | 608 | [
"Petroleum engineers",
"Petroleum engineering"
] |
67,345,123 | https://en.wikipedia.org/wiki/Rizia%20Bardhan | Rizia Bardhan is an Indian origin American biomolecular engineer who is an Associate Professor of Chemical & Biological Engineering at Iowa State University. She is Associate Editor of ACS Applied Materials & Interfaces.
Early life and education
Bardhan was an undergraduate student in chemistry at Westminster College and graduated in 2005. She moved to Rice University for her graduate studies, where she worked under the supervision of Naomi Halas. Bardhan completed her doctoral research at Rice, where she studied nanostructures for plasmonic enhancement. When these nanostructures are excited using light they can enhance the fluorescence signatures of nearby molecules. When molecules were 7 nm from the surface of these nanostructures, it was possible to generate an enhancement of 50 times of the fluorescent signal. After earning her doctorate, Bardhan was appointed a research fellow at the Molecular Foundry.
Research and career
Bardhan joined the faculty at Vanderbilt University in 2012. Her research considered nanomedicine and nanophotonics. In particular, Bardhan studied new imaging modalities for identifying immunomarkers, metabolic imaging using Raman spectroscopy, examinations of the mechano-molecular model of nanomaterials and the mechanisms that underpin photothermal immunotherapies.
In 2020, Bardhan joined the faculty at the Iowa State University as an Associate Professor of Chemical & Biological Engineering. She was awarded over $2 million in funding from the National Institutes of Health for her biomedical engineering program. Bardhan combined her experience creating plasmonic nanostructures with her understanding of immunomarkers to better predict who will respond well to immunotherapy. The approach combined immunoactive gold nanostructures with positron emission tomography and Raman spectroscopy, detecting tumour cells that were expressing a particular biomarker as well as immune cells.
Bardhan was made Associate Editor of ACS Applied Materials & Interfaces in 2021.
Awards and honors
2012 Forbes 30 Under 30
2013 National Science Foundation BRIGE Award
2014 Oak Ridge Associated Universities Ralph E. Powe Junior Faculty Enhancement Award
2020 Westminster College 40 Years, 40 Women Honorees
Selected publications
References
External links
Year of birth missing (living people)
Living people
American bioengineers
American biotechnologists
Westminster College (Missouri) alumni
Rice University alumni
Lawrence Berkeley National Laboratory people
Vanderbilt University faculty
Iowa State University faculty
21st-century American women scientists
Nanotechnologists
American women academics | Rizia Bardhan | [
"Materials_science"
] | 498 | [
"Nanotechnology",
"Nanotechnologists"
] |
67,345,230 | https://en.wikipedia.org/wiki/Gem%20towns | The gem towns are 51 British towns chosen by the Council for British Archaeology in 1964 from a list 324 historic towns and cities that were thought to be "particularly splendid and precious". The compilation of the list was in response to the 1963 Colin Buchanan report, Traffic in Towns and the redevelopment of Worcester town centre which was seen as insensitive and causing the loss of many heritage assets. The inclusion of a town on the list is still cited in tourist publicity and local authority development plans.
Origins and criteria
The list was compiled in response to the 1963 Colin Buchanan report, Traffic in Towns. It was also in the wake of the insensitive redevelopment of Worcester town centre, with the loss of many heritage assets. Gem towns have been described as having predominantly tourism-based economies that contrast with towns also worthy of preservation but which do not qualify as "gems" because they have an industrial past, or present, and so are less picturesque.
Ongoing significance
The status as a gem town has been used to resist development which is seen as diminishing the historic and attractive features of a town, such as the proposal to open a large discount store in medieval Cockermouth, Cumbria, in 2018 with those in favour citing the lower prices and greater choice that it would bring to residents who were forced to pay high prices locally or shop elsewhere, while those against argued that it would diminish the appeal of one of the last remaining intact gem towns.
The status of a town as a "gem" also continues to be mentioned in local government tourist publicity and in development plans, for instance in the plan for Whitehaven in 2013, and Lewes in 2015.
List of gem towns
The following towns and cities were identified as "gems".
Aberdeen
Abingdon
Barnard Castle
Bath
Beverley
Blandford
Bradford-on-Avon
Bridgnorth
Burford
Cambridge
Chipping Campden
Cockermouth
Colchester
Conway
Cromarty
Culross
Edinburgh and Leith
Haddington
Hadleigh
Hereford
Inveraray
Kelso
King's Lynn
Lavenham
Lewes
Lincoln
Ludlow
Marlborough
Monmouth
Newark-on-Trent
Newcastle upon Tyne
Norwich
Oxford
Pershore
Richmond
Rye
Salisbury
Sandwich
Scarborough
Stamford
Stirling
Tenby
Tewkesbury
Thaxted
Totnes
Warwick
Wells
Whitehaven
Wisbech
Wymondham
York
References
External links
Gem towns on Google Maps
https://www.bidwells.co.uk/news/living-in-a-conservation-area-ten-things-you-need-to-know/
Urban planning
Conservation in the United Kingdom
1964 in the United Kingdom | Gem towns | [
"Engineering"
] | 514 | [
"Urban planning",
"Architecture"
] |
67,345,490 | https://en.wikipedia.org/wiki/HD%2030080 | HD 30080, also known as HR 1509, is a solitary, orange hued star located in the southern constellation Caelum, the chisel. It has an apparent magnitude of 5.66, allowing it to be faintly visible to the naked eye. Parallax measurements from Gaia DR3 place the object at a distance of 612 light years. It appears to be approaching the Solar System with a heliocentric radial velocity of . Eggen (1989) lists it as a member of the thick disk population.
HD 30080 is an evolved red giant with a stellar classification of K3 III. It is currently on the red giant branch, generating energy by fusing a hydrogen shell around an inert helium core. It has 116% the mass of the Sun but has expanded to 41.6 times its girth. It radiates 299 times the luminosity of the Sun from its enlarged photosphere at an effective temperature of . HD 30080 has a solar metallicity and spins slowly with a projected rotational velocity of .
References
Caelum
K-type giants
30080
1509
CD-30 01968
021958
170882932
Caeli, 12 | HD 30080 | [
"Astronomy"
] | 244 | [
"Caelum",
"Constellations"
] |
67,346,535 | https://en.wikipedia.org/wiki/Batelapine | Batelapine (developmental code name CGS-13429) is a structural analogue of clozapine which was investigated as a potential antipsychotic.
References
External links
Batelapine - AdisInsight
Abandoned drugs
Antipsychotics
4-Methylpiperazin-1-yl compounds
Triazolobenzodiazepines
Tricyclic compounds | Batelapine | [
"Chemistry"
] | 76 | [
"Drug safety",
"Abandoned drugs"
] |
67,346,546 | https://en.wikipedia.org/wiki/A%20Philosophical%20Essay%20on%20Probabilities | A Philosophical Essay on Probabilities is a work by Pierre-Simon Laplace on the mathematical theory of probability. The book consists of two parts, the first with five chapters and the second with thirteen.
Table of Contents
Part I - A Philosophical Essay on Probabilities
Introduction
Concerning Probability
General Principles of the Calculus of Probability
Concerning Hope
Analytical Methods of the Calculus of Probability
Part II - Application of the Calculus of Probabilities
Games of Chance
Concerning the Unknown Inequalities which may Exist among Chances Supposed to be Equal
Concerning the Laws of Probability which result from the Indefinite Multiplication of Events
Application of the Calculus of Probabilities to Natural Philosophy
Application of the Calculus of Probabilities to the Moral Sciences
Concerning the Probability of Testimonies
Concerning the Selections and Deliberations of Assemblies
Concerning the Probability of the Judgements of Tribunals
Concerning Tables of Mortality, and the Mean Durations of Life, Marriage and Some Assemblies
Concerning the Benefits of Institutions which Depend on the Probability of Events
Concerning Illusions in the Estimation of Probabilities
Concerning the Various Means of Approaching Certainty
Historical Note of the Calculus of Probabilities to 1816
References
External links
A Philosophical Essay on Probabilities at Project Gutenberg
A Philosophical Essay on Probabilities at Internet Archive
History of probability and statistics
Probability books
1814 documents
19th-century essays
Pierre-Simon Laplace | A Philosophical Essay on Probabilities | [
"Mathematics"
] | 265 | [
"Probability and statistics",
"History of probability and statistics"
] |
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