source stringlengths 31 227 | text stringlengths 9 2k |
|---|---|
https://en.wikipedia.org/wiki/Serous%20gland | Serous glands secrete serous fluid. They contain serous acini, a grouping of serous cells that secrete serous fluid, isotonic with blood plasma, that contains enzymes such as alpha-amylase.
Serous glands are most common in the parotid gland and lacrimal gland but are also present in the submandibular gland and, to a far lesser extent, the sublingual gland. |
https://en.wikipedia.org/wiki/Data-driven%20programming | In computer programming, data-driven programming is a programming paradigm in which the program statements describe the data to be matched and the processing required rather than defining a sequence of steps to be taken. Standard examples of data-driven languages are the text-processing languages sed and AWK, and the document transformation language XSLT, where the data is a sequence of lines in an input stream – these are thus also known as line-oriented languages – and pattern matching is primarily done via regular expressions or line numbers.
Related paradigms
Data-driven programming is similar to event-driven programming, in that both are structured as pattern matching and resulting processing, and are usually implemented by a main loop, though they are typically applied to different domains. The condition/action model is also similar to aspect-oriented programming, where when a join point (condition) is reached, a pointcut (action) is executed. A similar paradigm is used in some tracing frameworks such as DTrace, where one lists probes (instrumentation points) and associated actions, which execute when the condition is satisfied.
Adapting abstract data type design methods to object-oriented programming results in a data-driven design. This type of design is sometimes used in object-oriented programming to define classes during the conception of a piece of software.
Applications
Data-driven programming is typically applied to streams of structured data, for filtering, transforming, aggregating (such as computing statistics), or calling other programs. Typical streams include log files, delimiter-separated values, or email messages, notably for email filtering. For example, an AWK program may take as input a stream of log statements, and for example send all to the console, write ones starting with WARNING to a "WARNING" file, and send an email to a sysadmin in case any line starts with "ERROR". It could also record how many warnings are logged per day. Al |
https://en.wikipedia.org/wiki/PBR322 | pBR322 is a plasmid and was one of the first widely used E. coli cloning vectors. Created in 1977 in the laboratory of Herbert Boyer at the University of California, San Francisco, it was named after Francisco Bolivar Zapata, the postdoctoral researcher and Raymond L. Rodriguez. The p stands for "plasmid," and BR for "Bolivar" and "Rodriguez."
pBR322 is 4361 base pairs in length and has two antibiotic resistance genes – the gene bla encoding the ampicillin resistance (AmpR) protein, and the gene tetA encoding the tetracycline resistance (TetR) protein. It contains the origin of replication of pMB1, and the rop gene, which encodes a restrictor of plasmid copy number. The plasmid has unique restriction sites for more than forty restriction enzymes. Eleven of these forty sites lie within the TetR gene. There are two sites for restriction enzymes HindIII and ClaI within the promoter of the TetR gene. There are six key restriction sites inside the AmpR gene.The source of these antibiotic resistance genes are from pSC101 for Tetracycline and RSF2124 for Ampicillin.
The circular sequence is numbered such that 0 is the middle of the unique EcoRI site and the count increases through the TetR gene. If we have to remove ampicillin for instance, we must use restriction endonuclease or molecular scissors against PstI and then pBR322 will become anti-resistant to ampicillin .The same process of Insertional Inactivation can be applied to Tetracycline. The AmpR gene is penicillin beta-lactamase. Promoters P1 and P3 are for the beta-lactamase gene. P3 is the natural promoter, and P1 is artificially created by the ligation of two different DNA fragments to create pBR322. P2 is in the same region as P1, but it is on the opposite strand and initiates transcription in the direction of the tetracycline resistance gene.
Background
Early cloning experiments may be conducted using natural plasmids such the ColE1 and pSC101. Each of these plasmids may have its advantages and disadvantage |
https://en.wikipedia.org/wiki/Return%20on%20capital%20employed | Return on capital employed is an accounting ratio used in finance, valuation, and accounting. It is a useful measure for comparing the relative profitability of companies after taking into account the amount of capital used.
The formula
(Expressed as a %)
It is similar to return on assets (ROA), but takes into account sources of financing.
Capital employed
In the denominator we have net assets or capital employed instead of total assets (which is the case of Return on Assets). Capital Employed has many definitions. In general it is the capital investment necessary for a business to function. It is commonly represented as total assets less current liabilities (or fixed assets plus working capital requirement).
ROCE uses the reported (period end) capital numbers; if one instead uses the average of the opening and closing capital for the period, one obtains return on average capital employed (ROACE).
Application
ROCE is used to prove the value the business gains from its assets and liabilities. Companies create value whenever they are able to generate returns on capital above the weighted average cost of capital (WACC). A business which owns much land will have a smaller ROCE compared to a business which owns little land but makes the same profit.
It basically can be used to show how much a business is gaining for its assets, or how much it is losing for its liabilities.
Drawbacks
The main drawback of ROCE is that it measures return against the book value of assets in the business. As these are depreciated the ROCE will increase even though cash flow has remained the same. Thus, older businesses with depreciated assets will tend to have higher ROCE than newer, possibly better businesses. In addition, while cash flow is affected by inflation, the book value of assets is not. Consequently, revenues increase with inflation while capital employed generally does not (as the book value of assets is not affected by inflation).
See also
Cash flow return on investment |
https://en.wikipedia.org/wiki/Adaptive%20resonance%20theory | Adaptive resonance theory (ART) is a theory developed by Stephen Grossberg and Gail Carpenter on aspects of how the brain processes information. It describes a number of neural network models which use supervised and unsupervised learning methods, and address problems such as pattern recognition and prediction.
The primary intuition behind the ART model is that object identification and recognition generally occur as a result of the interaction of 'top-down' observer expectations with 'bottom-up' sensory information. The model postulates that 'top-down' expectations take the form of a memory template or prototype that is then compared with the actual features of an object as detected by the senses. This comparison gives rise to a measure of category belongingness. As long as this difference between sensation and expectation does not exceed a set threshold called the 'vigilance parameter', the sensed object will be considered a member of the expected class. The system thus offers a solution to the 'plasticity/stability' problem, i.e. the problem of acquiring new knowledge without disrupting existing knowledge that is also called incremental learning.
Learning model
The basic ART system is an unsupervised learning model. It typically consists of a comparison field and a recognition field composed of neurons, a vigilance parameter (threshold of recognition), and a reset module.
The comparison field takes an input vector (a one-dimensional array of values) and transfers it to its best match in the recognition field.
Its best match is the single neuron whose set of weights (weight vector) most closely matches the input vector.
Each recognition field neuron outputs a negative signal (proportional to that neuron's quality of match to the input vector) to each of the other recognition field neurons and thus inhibits their output.
In this way the recognition field exhibits lateral inhibition, allowing each neuron in it to represent a category to which input vectors a |
https://en.wikipedia.org/wiki/Uterine%20artery%20embolization | Uterine artery embolization (UAE) is a procedure in which an interventional radiologist uses a catheter to deliver small particles that block the blood supply to the uterine body. The procedure is primarily done for the treatment of uterine fibroids and adenomyosis. However, it may also be used to treat postpartum hemorrhage and uterine arteriovenous fistulas. Since this minimally invasive procedure is commonly used in the treatment of uterine fibroids and is also called uterine fibroid embolization.
Medical uses
Uterine fibroids are the most common type of benign uterine tumor and are composed of smooth muscle. They often cause bulk-related symptoms, which can be characterized by back pain, heaviness in the pelvic area, abdominal bloating. UAE may be used to treat these bothersome bulk-related symptoms as well as abnormal or heavy uterine bleeding due to uterine fibroids. Fibroid size, number, and location are three potential predictors of a successful outcome. UAE may also be appropriate for the treatment of adenomyosis, which is when the lining of the uterus aberrantly grows into the muscle of the uterus. Symptoms of adenomyosis include heavy or prolonged menstrual bleeding and painful menstrual periods.
Long-term patient satisfaction outcomes are similar to that of surgery. There is tentative evidence that traditional surgery may result in better fertility. UAE also appears to require more repeat procedures than if surgery was done initially.
It has shorter recovery times. UAE is thought to work because uterine fibroids have abnormal vasculature together with aberrant responses to hypoxia (inadequate oxygenation to tissues).
UAE can also be used to control heavy uterine bleeding for reasons other than fibroids, such as postpartum obstetrical hemorrhage. and adenomyosis.
According to the American Journal of Gynecology, UAE costs 12% less than hysterectomy and 8% less than myomectomy.
Adverse effects
The rate of serious complications is comparable to that of |
https://en.wikipedia.org/wiki/Mired | Contracted from the term micro reciprocal degree, the mired is a unit of measurement used to express color temperature. Values in mireds are calculated by the formula:
where T is the colour temperature in units of kelvins and M denotes the resulting mired dimensionless number. The constant is one million kelvins.
The SI term for this unit is the reciprocal megakelvin (MK−1), shortened to mirek, but this term has not gained traction.
For convenience, decamireds are sometimes used, with each decamired equaling ten mireds.
The use of the term mired dates back to Irwin G. Priest's observation in 1932 that the just noticeable difference between two illuminants is based on the difference of the reciprocals of their temperatures, rather than the difference in the temperatures themselves.
Examples
A blue sky, which has a color temperature T of about , has a mired value of M = 40 mireds, while a standard electronic photography flash, having a color temperature T of 5000 K, has a mired value of M = 200 mireds.
In photography, mireds are used to indicate the color temperature shift provided by a filter or gel for a given film and light source. For instance, to use daylight film (5700 K) to take a photograph under a tungsten light source (3200 K) without introducing a color cast, one would need a corrective filter or gel providing a mired shift
This corresponds to a color temperature blue (CTB) filter.
Color gels with negative mired values appear green or blue, while those with positive values appear amber or red. |
https://en.wikipedia.org/wiki/Complex%20measure | In mathematics, specifically measure theory, a complex measure generalizes the concept of measure by letting it have complex values. In other words, one allows for sets whose size (length, area, volume) is a complex number.
Definition
Formally, a complex measure on a measurable space is a complex-valued function
that is sigma-additive. In other words, for any sequence of disjoint sets belonging to , one has
As for any permutation (bijection) , it follows that converges unconditionally (hence absolutely).
Integration with respect to a complex measure
One can define the integral of a complex-valued measurable function with respect to a complex measure in the same way as the Lebesgue integral of a real-valued measurable function with respect to a non-negative measure, by approximating a measurable function with simple functions. Just as in the case of ordinary integration, this more general integral might fail to exist, or its value might be infinite (the complex infinity).
Another approach is to not develop a theory of integration from scratch, but rather use the already available concept of integral of a real-valued function with respect to a non-negative measure. To that end, it is a quick check that the real and imaginary parts μ1 and μ2 of a complex measure μ are finite-valued signed measures. One can apply the Hahn-Jordan decomposition to these measures to split them as
and
where μ1+, μ1−, μ2+, μ2− are finite-valued non-negative measures (which are unique in some sense). Then, for a measurable function f which is real-valued for the moment, one can define
as long as the expression on the right-hand side is defined, that is, all four integrals exist and when adding them up one does not encounter the indeterminate ∞−∞.
Given now a complex-valued measurable function, one can integrate its real and imaginary components separately as illustrated above and define, as expected,
Variation of a complex measure and polar decomposition
For a complex mea |
https://en.wikipedia.org/wiki/Rubble%20pile | In astronomy, a rubble pile is a celestial body that is not a monolith, consisting instead of numerous pieces of rock that have coalesced under the influence of gravity. Rubble piles have low density because there are large cavities between the various chunks that make them up.
The asteroids Bennu and Ryugu have a measured bulk density which suggests that their internal structure is a rubble pile. Many comets and most smaller minor planets (<10 km in diameter) are thought to be composed of coalesced rubble.
Minor planets
Most smaller asteroids are thought to be rubble piles.
Rubble piles form when an asteroid or moon (which may originally be monolithic) is smashed to pieces by an impact, and the shattered pieces subsequently fall back together, primarily due to self-gravitation. This coalescing usually takes from several hours to weeks.
When a rubble-pile asteroid passes a much more massive object, tidal forces change its shape.
Scientists first suspected that asteroids are often rubble piles when asteroid densities were first determined. Many of the calculated densities were significantly less than those of meteorites, which in some cases had been determined to be pieces of asteroids.
Many asteroids with low densities are thought to be rubble piles, for example 253 Mathilde. The mass of Mathilde, as determined by the NEAR Shoemaker mission, is far too low for the volume observed, considering the surface is rock. Even ice with a thin crust of rock would not provide a suitable density. Also, the large impact craters on Mathilde would have shattered a rigid body. However, the first unambiguous rubble pile to be photographed is 25143 Itokawa, which has no obvious impact craters and is thus almost certainly a coalescence of shattered fragments.
The asteroid 433 Eros, the primary destination of NEAR Shoemaker, was determined to be riven with cracks but otherwise solid. Other asteroids, possibly including Itokawa, have been found to be contact binaries, two majo |
https://en.wikipedia.org/wiki/Monogram%20%28company%29 | Monogram is an American brand and former manufacturing company of scale plastic models of cars, aircraft, spacecraft, ships, and military vehicles since the early 1950s. The company was formed by two former employees of Comet Kits, Jack Besser and Bob Reder.
Mattel acquired Monogram in 1968, and the firm passed through various owners and was merged with Revell, the combined company being bought by Hobbico in 2007. Along with Revell, AMT, and MPC, Monogram is sometimes called one of the traditional "Big 4" in plastic modeling.
History
Monogram was founded in Chicago in 1945, making balsa wood model kits of ships and airplanes. Seaships such as the USS Missouri battleship, the USS Shangri-La carrier and the USS Hobby destroyer were among the first products. Meanwhile, a company called Revell started making plastic kits in 1953, and Monogram responded with "All Plastic" "Plastikits" the first of which were a red plastic midget racer and a "Hot Rod" Model A - and the modeling race was on. These two cars, and later an Indianapolis-style racer and hydroplane racing boat, were also offered with CO2 "Jet Power". Early kits advertised that the models were made from "acetate parts molded to shape". The wording showed the newness of the plastics industry and how plastics were not yet being taken for granted.
Early airplane models were mainly balsa wood, but more plastic parts were added over the next couple of years. By 1954 the airplane lineup consisted of the "Speedee Built" series which flew under rubber band power. A few of these planes were all-plastic. Also seen were the Superkits with a prefabricated balsa fuselage, but more plastic parts.
Auto kit makers AMT and Jo-Han started early but focused on manufacturers' promotional models and did not enter the kit fray until the late 1950s. As the 1950s progressed, Monogram increasingly included more automobile models and custom wheeled creations in competition with the other makers. Through the 1970s, competition requir |
https://en.wikipedia.org/wiki/Process%20optimization | Process optimization is the discipline of adjusting a process so as to optimize (make the best or most effective use of) some specified set of parameters without violating some constraint. The most common goals are minimizing cost and maximizing throughput and/or efficiency. This is one of the major quantitative tools in industrial decision making.
When optimizing a process, the goal is to maximize one or more of the process specifications, while keeping all others within their constraints. This can be done by using a process mining tool, discovering the critical activities and bottlenecks, and acting only on them.
Areas
Fundamentally, there are three parameters that can be adjusted to affect optimal performance. They are:
Equipment optimization
The first step is to verify that the existing equipment is being used to its fullest advantage by examining operating data to identify equipment bottlenecks.
Operating procedures
Operating procedures may vary widely from person-to-person or from shift-to-shift. Automation of the plant can help significantly. But automation will be of no help if the operators take control and run the plant in manual.
Control optimization
In a typical processing plant, such as a chemical plant or oil refinery, there are hundreds or even thousands of control loops. Each control loop is responsible for controlling one part of the process, such as maintaining a temperature, level, or flow.
If the control loop is not properly designed and tuned, the process runs below its optimum. The process will be more expensive to operate, and equipment will wear out prematurely. For each control loop to run optimally, identification of sensor, valve, and tuning problems is important. It has been well documented that over 35% of control loops typically have problems.
The process of continuously monitoring and optimizing the entire plant is sometimes called performance supervision.
See also
Calculation of glass properties, optimization of |
https://en.wikipedia.org/wiki/Electronics%20manufacturing%20services | Electronics Manufacturing Services (EMS) is a term used for companies that design, manufacture, test, distribute, and provide return/repair services for electronic components and assemblies for original equipment manufacturers (OEMs). The concept is also referred to as Electronics Contract Manufacturing (ECM).
Many consumer electronics are built in China, due to maintenance cost, availability of materials, and speed as opposed to other countries such as the United States. Cities such as Shenzhen and Penang have become important production centres for the industry, attracting many consumer electronics companies such as Apple Inc. Some companies such as Flex and Wistron are Original design manufacturers and providers of Electronics manufacturing services.
History
The EMS industry was initially established in 1961 by SCI Systems of Huntsville Alabama. The industry realized its most significant growth in the 1980s; at the time, most electronics manufacturing for large-scale product runs was handled by the OEMs in-house assembly. These new companies offered flexibility and eased human resources issues for smaller companies doing limited runs. The business model for the EMS industry is to specialize in large economies of scale in manufacturing, raw materials procurement and pooling together resources, industrial design expertise as well as create added value services such as warranty and repairs. This frees up the customer who does not need to manufacture and keep huge inventories of products. Therefore, they can respond to sudden spikes in demand more quickly and efficiently.
The development of Surface Mount Technology (SMT) on printed circuit boards (PCB) allowed for the rapid assembly of electronics. By the mid-1990s the advantages of the EMS concept became compelling and OEMs began outsourcing PCB assembly (PCBA) in large scale. By the end of the 1990s and early 2000s, many OEMs sold their assembly plants to EMSs, aggressively vying for market share. A wave of con |
https://en.wikipedia.org/wiki/Free%20Boolean%20algebra | In mathematics, a free Boolean algebra is a Boolean algebra with a distinguished set of elements, called generators, such that:
Each element of the Boolean algebra can be expressed as a finite combination of generators, using the Boolean operations, and
The generators are as independent as possible, in the sense that there are no relationships among them (again in terms of finite expressions using the Boolean operations) that do not hold in every Boolean algebra no matter which elements are chosen.
A simple example
The generators of a free Boolean algebra can represent independent propositions. Consider, for example, the propositions "John is tall" and "Mary is rich". These generate a Boolean algebra with four atoms, namely:
John is tall, and Mary is rich;
John is tall, and Mary is not rich;
John is not tall, and Mary is rich;
John is not tall, and Mary is not rich.
Other elements of the Boolean algebra are then logical disjunctions of the atoms, such as "John is tall and Mary is not rich, or John is not tall and Mary is rich". In addition there is one more element, FALSE, which can be thought of as the empty disjunction; that is, the disjunction of no atoms.
This example yields a Boolean algebra with 16 elements; in general, for finite n, the free Boolean algebra with n generators has 2n atoms, and therefore elements.
If there are infinitely many generators, a similar situation prevails except that now there are no atoms. Each element of the Boolean algebra is a combination of finitely many of the generating propositions, with two such elements deemed identical if they are logically equivalent.
Another way to see why the free Boolean algebra on an n-element set has elements is to note that each element is a function from n bits to one. There are possible inputs to such a function and the function will choose 0 or 1 to output for each input, so there are possible functions.
Category-theoretic definition
In the language of category theory, free Boolean a |
https://en.wikipedia.org/wiki/Animal%20song | Animal song is not a well-defined term in scientific literature, and the use of the more broadly defined term vocalizations is in more common use. Song generally consists of several successive vocal sounds incorporating multiple syllables. Some sources distinguish between simpler vocalizations, termed “calls”, reserving the term “song” for more complex productions. Song-like productions have been identified in several groups of animals, including cetaceans (whales and dolphins), avians (birds), anurans (frogs), and humans. Social transmission of song has been found in groups including birds and cetaceans.
Anatomy of sound production
Mammals
Most mammalian species produce sound by passing air from the lungs across the larynx, vibrating the vocal folds. Sound then enters the supralaryngeal vocal tract, which can be adjusted to produce various changes in sound output, providing refinement of vocalizations. Although morphological differences between species affect production of sound, neural control is thought to be more essential factor in producing the variations within human speech and song compared to those of other mammals. Cetacean vocalizations are an exception to this general mechanism. Toothed whales (Odontocetes) pass air through a system of air sacs and muscular phonic lips, which vibrate to produce audible vocalizations, thus serving the function of vocal folds in other mammals. Sound vibrations are conveyed to an organ in the head called the melon, which can be changed in shape to control and direct vocalizations. Unlike in humans and other mammals, toothed whales are able to recycle air used in vocal production, allowing whales to sing without releasing air. Some cetaceans, such as humpback whales, sing continuously for hours.
Anurans
Like mammals, anurans possess a larynx and vocal folds, which are used to create vibrations in sound production. However, frogs also use structures called vocal sacs, elastic membranes in the base of the mouth which in |
https://en.wikipedia.org/wiki/Atom%20%28measure%20theory%29 | In mathematics, more precisely in measure theory, an atom is a measurable set which has positive measure and contains no set of smaller positive measure. A measure which has no atoms is called non-atomic or atomless.
Definition
Given a measurable space and a measure on that space, a set in is called an atom if
and for any measurable subset with
the set has measure zero, i.e. .
If is an atom, all the subsets in the -equivalence class of are atoms, and is called an atomic class. If is a -finite measure, there are countably many atomic classes.
Examples
Consider the set X = {1, 2, ..., 9, 10} and let the sigma-algebra be the power set of X. Define the measure of a set to be its cardinality, that is, the number of elements in the set. Then, each of the singletons {i}, for i = 1, 2, ..., 9, 10 is an atom.
Consider the Lebesgue measure on the real line. This measure has no atoms.
Atomic measures
A -finite measure on a measurable space is called atomic or purely atomic if every measurable set of positive measure contains an atom. This is equivalent to say that there is a countable partition of formed by atoms up to a null set. The assumption of -finitude is essential. Consider otherwise the space where denotes the counting measure. This space is atomic, with all atoms being the singletons, yet the space is not able to be partitioned into the disjoint union of countably many disjoint atoms, and a null set since the countable union of singletons is a countable set, and the uncountability of the real numbers shows that the complement would have to be uncountable, hence its -measure would be infinite, in contradiction to it being a null set. The validity of the result for -finite spaces follows from the proof for finite measure spaces by observing that the countable union of countable unions is again a countable union, and that the countable unions of null sets are null.
Discrete measures
A -finite atomic measure is called discrete if the inters |
https://en.wikipedia.org/wiki/Valence%20bond%20programs | Valence bond (VB) computer programs for modern valence bond calculations:-
CRUNCH, by Gordon A. Gallup and his group.
GAMESS (UK), includes calculation of VB wave functions by the TURTLE code, due to J.H. van Lenthe.
GAMESS (US), has links to interface VB2000, and XMVB.
MOLPRO and MOLCAS include code by David L. Cooper for generating Spin Coupled VB wave functions from CASSCF calculations.
VB2000 version 2.7 (released, 2014), by Jiabo Li, Brian Duke and Roy McWeeny allows the use of Group Function theory, whereby different groups can be handled by different methods (VB or Hartree–Fock). Many types of VB, including spin-coupled VB, and CASVB calculations are possible. It is part of the GAMESS (US) release and can be compiled into the GAMESS(US) executable. There is a more limited stand-alone program. Earlier versions were interfaced to GAUSSIAN.
XMVB (previously known as XIAMEN), by Lingchun Song, Yirong Mo, Qianer Zhang and Wei Wu. This allows several VB methods, including breathing orbital VB. The code now interfaces to GAMESS (US) in a similar manner to VB2000. Earlier versions interfaced to GAUSSIAN 98.
Note that several other programs, as well as some of those above, can do Goddard's Generalized Valence Bond (GVB) methods. GAMESS (US) does this either without the VB2000 interface or with it.
See also
Quantum chemistry computer programs |
https://en.wikipedia.org/wiki/Hyoglossus | The hyoglossus is a thin and quadrilateral extrinsic muscle of the tongue. It originates from the hyoid bone; it inserts onto the side of the tongue. It is innervated by the hypoglossal nerve (cranial nerve XII). It acts to depress and retract the tongue.
Structure
It forms a part of the floor of submandibular triangle.
Origin
from the side of the body and from the whole length of the greater cornu of the hyoid bone. The fibers arising from the body of the hyoid bone overlap those from the greater cornu.
Insertion
Its fibres pass almost vertically upward to enter the side of the tongue, inserting between the styloglossus and the inferior longitudinal muscle of the tongue.
Relations
Structures that are medial/deep to the hyoglossus are the glossopharyngeal nerve (CN IX), the stylohyoid ligament and the lingual artery and lingual vein.
The lingual vein passes medial to the hyoglossus. The lingual artery passes deep to the hyoglossus.
Laterally, in between the hyoglossus muscle and the mylohyoid muscle, lay several important structures (from upper to lower): sublingual gland, submandibular duct, lingual nerve, vena comitans of hypoglossal nerve, and the hypoglossal nerve. Note, posteriorly, the lingual nerve is superior to the submandibular duct and a portion of the submandibular salivary gland protrudes into the space between the hyoglossus and mylohyoid muscles.
Function
The hyoglossus depresses and retracts the tongue and makes the dorsum more convex.
Additional images |
https://en.wikipedia.org/wiki/Styloglossus | The styloglossus muscle is a bilaterally paired muscle of the tongue. It originates at the styloid process of the temporal bone. It inserts onto the side of the tongue. It acts to elevate and retract the tongue. It is innervated by the hypoglossal nerve (cranial nerve XII).
Anatomy
The styloglossus muscle is the shortest and smallest of the three styloid muscles.
Origin
It arises from (the anterior and lateral surfaces of) the styloid process of the temporal bone near its apex, and from the stylomandibular ligament.
Course and relations
It passes anterioinferiorly from its origin to its insertion between the internal carotid artery and the external carotid artery, and between the superior pharyngeal constrictor muscle and the middle pharyngeal constrictor muscle.
Insertion
It divides upon the side of the tongue near the dorsal surface of the tongue, blending with the fibers of the longitudinalis inferior muscle anterior to the hyoglossus muscle.
Innervation
The styloglossus is innervated by the hypoglossal nerve (CN XII) (like all muscles of the tongue except palatoglossus which is innervated by the pharyngeal plexus of vagus nerve (CN X)).
Function
The styloglossus draws up the sides of the tongue to create a trough for swallowing. Acting bilaterally (both styloglossus muscles contracting simultaneously) they also aid in retracting the tongue.
Additional images |
https://en.wikipedia.org/wiki/Palatoglossus%20muscle | The palatoglossal muscle is a muscle of the soft palate and an extrinsic muscle of the tongue. Its surface is covered by oral mucosa and forms the visible palatoglossal arch.
Structure
From its origin, it passes anteroinferiorly and laterally. It passes anterior to the palatine tonsil.
Origin
The palatoglossus arises (the oral aspect of) the palatine aponeurosis of the soft palate, where it is continuous with its contralateral partner (i.e. the same muscle of the opposite side).
Insertion
It inserts onto the side of the tongue; some of its fibers extend over the dorsum of the tongue, and some pass into the substance of the tongue to intermingle with the transverse muscle of tongue.
Innervation
The palatoglossus muscle receives motor innervation from the pharyngeal plexus of vagus nerve.
It is the only muscle of the tongue not innervated by the hypoglossal nerve (CN XII).
Controversy
Some sources state that the palatoglossus is innervated by fibers from the cranial part of the accessory nerve (CN XI) that travel via the pharyngeal plexus.
Other sources state that the palatoglossus is not innervated by XI hitchhiking on X, but rather it is innervated by IX via the pharyngeal plexus formed from IX and X.
Actions/movements
The palatoglossus elevates the root of the tongue (i.e. the posterior attached portion of the tongue). It approximates the ipsilateral (same side) palatoglossal arch to the contralateral (opposite side) one, thus separating the oral cavity and the oropharynx.
Function
It closes the oropharyngeal isthmus, and aids initiation of swallowing. This muscle also prevents the spill of saliva from vestibule into the oropharynx by maintaining the palatoglossal arch. |
https://en.wikipedia.org/wiki/Oenophilia | Oenophilia ( ; Greek) is a love (philia) of wine (oinos). In the strictest sense, oenophilia describes a disciplined devotion to wine, accompanying strict traditions of consumption and appreciation. In a general sense however, oenophilia simply refers to the enjoyment of wine, often by laymen. Oenophiles are also known as wine aficionados or connoisseurs. They are people who appreciate or collect wine, particularly grape wines from certain regions, varietal types, or methods of manufacture. While most oenophiles are hobbyists, some may also be professionals like vintners, sommeliers, wine merchants, or one who tastes and grades wines for a living.
According to the Oxford English Dictionary, the earliest occurrence of the word oenophile was in 1865 in Culture of the Vine and Wine Making, an English translation of a French book by Jules Guyot. The word oenophilia was initially primarily used in contexts of excessive drinking, and in its earliest occurrence in 1908, spelled oinophilia. It became common in the wine lexicon in 1977 when Shirley Copperman used it for her new bring-your-own-wine restaurant she and her husband dubbed "Oenophilia", located on the upper West Side of Manhattan. A reviewer in a local paper, The Westsider, wrote about the debut: "If the name suggests a rare disease you wouldn't want to catch, a sign in the window informs you that you may already have it. 'Oenophilia', it says, 'is an affliction of the senses characterized by intense cravings for good food and service and vintage wines served in a tasteful, comfortable setting at reasonable prices.'" The reviewer from The Village Voice wrote in 1977: "Oenophilia. No, not a social disease. It's the sensual orientation towards the pleasures of fine food and wine, and the name of a spiffy new bistro for elegant gourmandizing....'"
See also
Oenology |
https://en.wikipedia.org/wiki/Volcanic%20gas | Volcanic gases are gases given off by active (or, at times, by dormant) volcanoes. These include gases trapped in cavities (vesicles) in volcanic rocks, dissolved or dissociated gases in magma and lava, or gases emanating from lava, from volcanic craters or vents. Volcanic gases can also be emitted through groundwater heated by volcanic action.
The sources of volcanic gases on Earth include:
primordial and recycled constituents from the Earth's mantle,
assimilated constituents from the Earth's crust,
groundwater and the Earth's atmosphere.
Substances that may become gaseous or give off gases when heated are termed volatile substances.
Composition
The principal components of volcanic gases are water vapor (H2O), carbon dioxide (CO2), sulfur either as sulfur dioxide (SO2) (high-temperature volcanic gases) or hydrogen sulfide (H2S) (low-temperature volcanic gases), nitrogen, argon, helium, neon, methane, carbon monoxide and hydrogen. Other compounds detected in volcanic gases are oxygen (meteoric), hydrogen chloride, hydrogen fluoride, hydrogen bromide, sulfur hexafluoride, carbonyl sulfide, and organic compounds. Exotic trace compounds include mercury, halocarbons (including CFCs), and halogen oxide radicals.
The abundance of gases varies considerably from volcano to volcano, with volcanic activity and with tectonic setting. Water vapour is consistently the most abundant volcanic gas, normally comprising more than 60% of total emissions. Carbon dioxide typically accounts for 10 to 40% of emissions.
Volcanoes located at convergent plate boundaries emit more water vapor and chlorine than volcanoes at hot spots or divergent plate boundaries. This is caused by the addition of seawater into magmas formed at subduction zones. Convergent plate boundary volcanoes also have higher H2O/H2, H2O/CO2, CO2/He and N2/He ratios than hot spot or divergent plate boundary volcanoes.
Magmatic gases and high-temperature volcanic gases
Magma contains dissolved volatile componen |
https://en.wikipedia.org/wiki/Schubert%20calculus | In mathematics, Schubert calculus is a branch of algebraic geometry introduced in the nineteenth century by Hermann Schubert, in order to solve various counting problems of projective geometry (part of enumerative geometry). It was a precursor of several more modern theories, for example characteristic classes, and in particular its algorithmic aspects are still of current interest. The term Schubert calculus is sometimes used to mean the enumerative geometry of linear subspaces of a vector space, which is roughly equivalent to describing the cohomology ring of Grassmannians. Sometimes it is used to mean the more general enumerative geometry of algebraic varieties that are homogenous spaces of simple Lie groups. Even more generally, Schubert calculus is often understood to encompass the study of analogous questions in generalized cohomology theories.
The objects introduced by Schubert are the Schubert cells, which are locally closed sets in a Grassmannian defined by conditions of incidence of a linear subspace in projective space with a given flag. For further details see Schubert variety.
The intersection theory of these cells, which can be seen as the product structure in the cohomology ring of the Grassmannian of associated cohomology classes, in principle allows the prediction of the cases where intersections of cells results in a finite set of points, which are potentially concrete answers to enumerative questions. A key result is that the Schubert cells (or rather, the classes of their Zariski closures, the Schubert cycles or Schubert varieties) span the whole cohomology ring.
The combinatorial aspects mainly arise in relation to computing intersections of Schubert cycles. Lifted from the Grassmannian, which is a homogeneous space, to the general linear group that acts on it, similar questions are involved in the Bruhat decomposition and classification of parabolic subgroups (as block traingular matrices).
Putting Schubert's system on a rigorous footing wa |
https://en.wikipedia.org/wiki/Homogeneous%20broadening | Homogeneous broadening is a type of emission spectrum broadening in which all atoms radiating from a specific level under consideration radiate with equal opportunity. If an optical emitter (e.g. an atom) shows homogeneous broadening, its spectral linewidth is its natural linewidth, with a Lorentzian profile.
Broadening in laser systems
Broadening in laser physics is a physical phenomenon that affects the spectroscopic line shape of the laser emission profile. The laser emission is due to the (excitation and subsequent) relaxation of a quantum system (atom, molecule, ion, etc.) between an excited state (higher in energy) and a lower one. These states can be thought of as the eigenstates of the energy operator. The difference in energy between these states is proportional to the frequency/wavelength of the photon emitted. Since this energy difference has a fluctuation, then the frequency/wavelength of the "macroscopic emission" (the beam) will have a certain width (i.e. it will be "broadened" with respect to the "ideal" perfectly monochromatic emission).
Depending on the nature of the fluctuation, there can be two types of broadening. If the fluctuation in the frequency/wavelength is due to a phenomenon that is the same for each quantum emitter, there is homogeneous broadening, while if each quantum emitter has a different type of fluctuation, the broadening is inhomogeneous.
Examples of situations where the fluctuation is the same for each system (homogeneous broadening) are natural or lifetime broadening, and collisional or pressure broadening. In these cases each system is affected "on average" in the same way (e.g. by the collisions due to the pressure).
The most frequent situation in solid state systems where the fluctuation is different for each system (inhomogeneous broadening) is when because of the presence of dopants, the local electric field is different for each emitter, and so the Stark effect changes the energy levels in an inhomogeneous way. The ho |
https://en.wikipedia.org/wiki/Anonymous%20recursion | In computer science, anonymous recursion is recursion which does not explicitly call a function by name. This can be done either explicitly, by using a higher-order function – passing in a function as an argument and calling it – or implicitly, via reflection features which allow one to access certain functions depending on the current context, especially "the current function" or sometimes "the calling function of the current function".
In programming practice, anonymous recursion is notably used in JavaScript, which provides reflection facilities to support it. In general programming practice, however, this is considered poor style, and recursion with named functions is suggested instead. Anonymous recursion via explicitly passing functions as arguments is possible in any language that supports functions as arguments, though this is rarely used in practice, as it is longer and less clear than explicitly recursing by name.
In theoretical computer science, anonymous recursion is important, as it shows that one can implement recursion without requiring named functions. This is particularly important for the lambda calculus, which has anonymous unary functions, but is able to compute any recursive function. This anonymous recursion can be produced generically via fixed-point combinators.
Use
Anonymous recursion is primarily of use in allowing recursion for anonymous functions, particularly when they form closures or are used as callbacks, to avoid having to bind the name of the function.
Anonymous recursion primarily consists of calling "the current function", which results in direct recursion. Anonymous indirect recursion is possible, such as by calling "the caller (the previous function)", or, more rarely, by going further up the call stack, and this can be chained to produce mutual recursion. The self-reference of "the current function" is a functional equivalent of the "this" keyword in object-oriented programming, allowing one to refer to the current context. |
https://en.wikipedia.org/wiki/Estimation%20of%20distribution%20algorithm | Estimation of distribution algorithms (EDAs), sometimes called probabilistic model-building genetic algorithms (PMBGAs), are stochastic optimization methods that guide the search for the optimum by building and sampling explicit probabilistic models of promising candidate solutions. Optimization is viewed as a series of incremental updates of a probabilistic model, starting with the model encoding an uninformative prior over admissible solutions and ending with the model that generates only the global optima.
EDAs belong to the class of evolutionary algorithms. The main difference between EDAs and most conventional evolutionary algorithms is that evolutionary algorithms generate new candidate solutions using an implicit distribution defined by one or more variation operators, whereas EDAs use an explicit probability distribution encoded by a Bayesian network, a multivariate normal distribution, or another model class. Similarly as other evolutionary algorithms, EDAs can be used to solve optimization problems defined over a number of representations from vectors to LISP style S expressions, and the quality of candidate solutions is often evaluated using one or more objective functions.
The general procedure of an EDA is outlined in the following:
t := 0
initialize model M(0) to represent uniform distribution over admissible solutions
while (termination criteria not met) do
P := generate N>0 candidate solutions by sampling M(t)
F := evaluate all candidate solutions in P
M(t + 1) := adjust_model(P, F, M(t))
t := t + 1
Using explicit probabilistic models in optimization allowed EDAs to feasibly solve optimization problems that were notoriously difficult for most conventional evolutionary algorithms and traditional optimization techniques, such as problems with high levels of epistasis. Nonetheless, the advantage of EDAs is also that these algorithms provide an optimization practitioner with a series of probabilistic models that reveal a lot o |
https://en.wikipedia.org/wiki/H%C3%BCrthle%20cell | A Hürthle cell is a cell in the thyroid that is often associated with Hashimoto's thyroiditis as well as benign and malignant tumors (Hürthle cell adenoma and Hürthle cell carcinoma, formerly considered a subtype of follicular thyroid cancer). This version is a relatively rare form of differentiated thyroid cancer, accounting for only 3-10% of all differentiated thyroid cancers. Oncocytes in the thyroid are often called Hürthle cells. Although the terms oncocyte, oxyphilic cell, and Hürthle cell are used interchangeably, Hürthle cell is used only to indicate cells of thyroid follicular origin.
Diseases
Hürthle cell neoplasms can be separated into Hürthle cell adenomas and carcinomas, which are respectively benign and malignant tumors arising from the follicular epithelium of the thyroid gland. The mitochondrial DNA of Hürthle cell carcinoma contain somatic mutations. Hürthle cell carcinomas consists of at least 75% Hürthle cells. Chronic lymphocytic thyroiditis or Hashimoto's thyroiditis, along with cases of long-standing Graves' disease, show Hürthle cells present.
Diagnosis
Hürthle cell adenomas are most likely diagnosed much more frequently than Hürthle cell carcinomas. The female to male ratio for Hurthle cell adenomas is 8:1, while the ratio is 2:1 for the malignant version. Hürthle cell cancer tends to occur in older patients. The median age at diagnosis for Hürthle cell carcinomas is approximately 61 years old. Typically a painless thyroid mass is found in patients with this type of cancer. As expected, patients with carcinoma usually present larger tumors than patients with adenoma. Rarely, the cancer can spread to the lymph nodes. On few occasions, patients with Hürthle cell carcinoma have distant metastases in the lungs or surrounding bones. Hürthle cell neoplasms are somewhat difficult to differentiate between being benign or malignant. Since the size and growth pattern of the tumor cannot be used to determine malignancy, although larger tumors have h |
https://en.wikipedia.org/wiki/Abdallat%E2%80%93Davis%E2%80%93Farrage%20syndrome | Abdallat–Davis–Farrage syndrome is a form of phakomatosis, a disease of the central nervous system accompanied by skin abnormalities. It is characterized by the out of the ordinary pigment of the skin that is abnormal to one's genetics or the color perceived on a basis.
The condition is named after the team of medical professionals who first wrote it up, describing the appearance of the syndrome in a family from Jordan. It was characterized in 1980 by Adnan Abdallat, a Jordanian doctor.
Signs and symptoms
Clinical presentation is as follows:
Albinism (hair)
Irregular decreased skin pigmentation
Excessive freckling
Insensitivity to pain
Paraparesis/quadraparesis
Genetics
The syndrome is thought to be inherited as an autosomal recessive genetic trait, meaning that in order to manifest symptoms, a person must inherit a gene for Abdallat–Davis–Farrage syndrome from both parents. As it is also autosomal (not linked to either of the genes that determine gender), it can manifest in both men and women. Those with only one gene are carriers, and they typically manifest no symptoms; in the event that a person inherits both genes, symptoms usually appear before one year of age.
Treatment |
https://en.wikipedia.org/wiki/Neuroinformatics | Neuroinformatics is the field that combines informatics and neuroscience. Neuroinformatics is related with neuroscience data and information processing by artificial neural networks. There are three main directions where neuroinformatics has to be applied:
the development of computational models of the nervous system and neural processes.
the development of tools for analyzing and modeling neuroscience data,
the development of tools and databases for management and sharing of neuroscience data at all levels of analysis,
Neuroinformatics is related to philosophy (computational theory of mind), psychology (information processing theory), computer science (natural computing, bio-inspired computing), among others. Neuroinformatics doesn't deal with matter or energy, so it can be seen as a branch of neurobiology that studies various aspects of nervous systems. The term neuroinformatics seems to be used synonymously with cognitive informatics, described by Journal of Biomedical Informatics as interdisciplinary domain that focuses on human information processing, mechanisms and processes within the context of computing and computing applications. According to German National Library, neuroinformatics is synonymous with neurocomputing. At Proceedings of the 10th IEEE International Conference on Cognitive Informatics and Cognitive Computing was introduced the following description: Cognitive Informatics (CI) as a transdisciplinary enquiry of computer science, information sciences, cognitive science, and intelligence science. CI investigates into the internal information processing mechanisms and processes of the brain and natural intelligence, as well as their engineering applications in cognitive computing. According to INCF, neuroinformatics is a research field devoted to the development of neuroscience data and knowledge bases together with computational models.
Neuroinformatics in neuropsychology and neurobiology
Models of neural computation
Models of neural compu |
https://en.wikipedia.org/wiki/SHORT%20syndrome | SHORT syndrome is a medical condition in which affected individuals have multiple birth defects in different organ systems.
It was characterized in 1975.
Presentation
SHORT is an acronym for short stature, hyperextensibility of joints and/or inguinal hernia, ocular depression, Rieger anomaly and teething delay. Other characteristics common in SHORT syndrome are a triangular face, a prominent forehead, small chin with a dimple, a loss of fat under the skin (lipodystrophy), prominent ears (but no low implantation or posterior localisation), hearing loss and delayed speech. Facial lipodystrophy may be evident during birth and later on in the chest and higher extremities, but it usually won't affect buttocks and legs. Diabetes has been observed in ⅔ of the affected after they turn 15.
Diagnosis
Diagnosis is based on facial characteristics and molecular genetic testing that will show a mutation on gene PIK3R1 (5q13.1), which codifies the regulating alpha subunit of phosphatidylinositol 3-kinase. This mutation can alter the PI3K/AKT/mTOR signal route, which plays an important role in cell growth and proliferation.
Treatment
Treatment involves multiple disciplines.
-Screening for insulin resistance during late childhood stage.
-Glucose intolerance and diabetes mellitus can be treated with a different diet and lifestyle changes.
-Regular eye checkups are recommended in order to keep vision.
-Dental anomalies can be treated with common methods (protheses, crown, etc.) |
https://en.wikipedia.org/wiki/Neptune%20trojan | Neptune trojans are bodies that orbit the Sun near one of the stable Lagrangian points of Neptune, similar to the trojans of other planets. They therefore have approximately the same orbital period as Neptune and follow roughly the same orbital path. Thirty-one Neptune trojans are currently known, of which 27 orbit near the Sun–Neptune Lagrangian point 60° ahead of Neptune and four orbit near Neptune's region 60° behind Neptune. The Neptune trojans are termed 'trojans' by analogy with the Jupiter trojans.
The discovery of in a high-inclination (>25°) orbit was significant, because it suggested a "thick" cloud of trojans (Jupiter trojans have inclinations up to 40°), which is indicative of freeze-in capture instead of in situ or collisional formation. It is suspected that large (radius ≈ 100 km) Neptune trojans could outnumber Jupiter trojans by an order of magnitude.
In 2010, the discovery of the first known Neptune trojan, , was announced. Neptune's trailing region is currently very difficult to observe because it is along the line of sight to the center of the Milky Way, an area of the sky crowded with stars.
Discovery and exploration
In 2001, the first Neptune trojan was discovered, , near Neptune's region, and with it the fifth known populated stable reservoir of small bodies in the Solar System. In 2005, the discovery of the high-inclination trojan has indicated that the Neptune trojans populate thick clouds, which has constrained their possible origins (see below).
On August 12, 2010, the first trojan, , was announced. It was discovered by a dedicated survey that scanned regions where the light from the stars near the Galactic Center is obscured by dust clouds. This suggests that large trojans are as common as large trojans, to within uncertainty, further constraining models about their origins (see below).
It would have been possible for the New Horizons spacecraft to investigate Neptune trojans discovered by 2014, when it passed through this |
https://en.wikipedia.org/wiki/Oral%20myology | Oral myology (also known as "orofacial myology") is the field of study that involves the evaluation and treatment (known as "orofacial myofunctional therapy") of the oral and facial musculature, including the muscles of the tongue, lips, cheeks, and jaw.
Use
Orofacial myofunctional therapy treatment is most commonly used to retrain oral rest posture, swallowing patterns in the oral phase, and speech.
Tongue thrust and thumb sucking
A major focus of the field of oral myology and treatment of orofacial myofunctional disorders include tongue posture and establishing equilibrium between the tongue, lips and the cheek muscles. Tongue exercise proved to be successful in treating tongue thrust. Tongue exercise alone was reported to be successful in cessation of thumb sucking and treatment of anterior open bite malocclusion. When the tongue rests against the palate it begins to expand the maxilla by applying a slow and consistent force to the lingual (tongue side) surfaces of the teeth. This may aid in the treatment of crooked teeth and under-developed face.
Sleep apnea and snoring
Oral myology plays also an important role in the management of patients with sleep breathing disorders and snoring where oropharyngeal exercises were found to reduce the severity and primary symptoms of obstructive sleep apnea. Poor positioning of the tongue affects breathing and allows a series of events to occur that can affect the orofacial complex. Patients with sleep apnea and other breathing difficulties usually have decreased tone and mobility in the cheek, tongue, lip, and soft palate, and sensory alterations due to a tendency to engage in mouth breathing rather than nasal breathing. In treatment of sleep apnea, oral myology therapy involves a series of exercises designed to improve tongue position and tongue function for a better control of the extrinsic tongue muscles and place the tongue in a ‘‘proper posture during function and at rest.’’
Dysphagia
Disruption of normal swallowi |
https://en.wikipedia.org/wiki/Nielsen%20realization%20problem | The Nielsen realization problem is a question asked by about whether finite subgroups of mapping class groups can act on surfaces, that was answered positively by .
Statement
Given an oriented surface, we can divide the group Diff(S), the group of diffeomorphisms of the surface to itself, into isotopy classes to get the mapping class group π0(Diff(S)). The conjecture asks whether a finite subgroup of the mapping class group of a surface can be realized as the isometry group of a hyperbolic metric on the surface.
The mapping class group acts on Teichmüller space. An equivalent way of stating the question asks whether every finite subgroup of the mapping class group fixes some point of Teichmüller space.
History
asked whether finite subgroups of mapping class groups can act on surfaces.
claimed to solve the Nielsen realization problem but his proof depended on trying to show that Teichmüller space (with the Teichmüller metric) is negatively curved. pointed out a gap in the argument, and showed that Teichmüller space is not negatively curved. gave a correct proof that finite subgroups of mapping class groups can act on surfaces using left earthquakes. |
https://en.wikipedia.org/wiki/Partially%20observable%20Markov%20decision%20process | A partially observable Markov decision process (POMDP) is a generalization of a Markov decision process (MDP). A POMDP models an agent decision process in which it is assumed that the system dynamics are determined by an MDP, but the agent cannot directly observe the underlying state. Instead, it must maintain a sensor model (the probability distribution of different observations given the underlying state) and the underlying MDP. Unlike the policy function in MDP which maps the underlying states to the actions, POMDP's policy is a mapping from the history of observations (or belief states) to the actions.
The POMDP framework is general enough to model a variety of real-world sequential decision processes. Applications include robot navigation problems, machine maintenance, and planning under uncertainty in general. The general framework of Markov decision processes with imperfect information was described by Karl Johan Åström in 1965 in the case of a discrete state space, and it was further studied in the operations research community where the acronym POMDP was coined. It was later adapted for problems in artificial intelligence and automated planning by Leslie P. Kaelbling and Michael L. Littman.
An exact solution to a POMDP yields the optimal action for each possible belief over the world states. The optimal action maximizes the expected reward (or minimizes the cost) of the agent over a possibly infinite horizon. The sequence of optimal actions is known as the optimal policy of the agent for interacting with its environment.
Definition
Formal definition
A discrete-time POMDP models the relationship between an agent and its environment. Formally, a POMDP is a 7-tuple , where
is a set of states,
is a set of actions,
is a set of conditional transition probabilities between states,
is the reward function.
is a set of observations,
is a set of conditional observation probabilities, and
is the discount factor.
At each time period, the environment i |
https://en.wikipedia.org/wiki/Control%20variates | The control variates method is a variance reduction technique used in Monte Carlo methods. It exploits information about the errors in estimates of known quantities to reduce the error of an estimate of an unknown quantity.
Underlying principle
Let the unknown parameter of interest be , and assume we have a statistic such that the expected value of m is μ: , i.e. m is an unbiased estimator for μ. Suppose we calculate another statistic such that is a known value. Then
is also an unbiased estimator for for any choice of the coefficient .
The variance of the resulting estimator is
By differentiating the above expression with respect to , it can be shown that choosing the optimal coefficient
minimizes the variance of . (Note that this coefficient is the same as the coefficient obtained from a linear regression.) With this choice,
where
is the correlation coefficient of and . The greater the value of , the greater the variance reduction achieved.
In the case that , , and/or are unknown, they can be estimated across the Monte Carlo replicates. This is equivalent to solving a certain least squares system; therefore this technique is also known as regression sampling.
When the expectation of the control variable, , is not known analytically, it is still possible to increase the precision in estimating (for a given fixed simulation budget), provided that the two conditions are met: 1) evaluating is significantly cheaper than computing ; 2) the magnitude of the correlation coefficient is close to unity.
Example
We would like to estimate
using Monte Carlo integration. This integral is the expected value of , where
and U follows a uniform distribution [0, 1].
Using a sample of size n denote the points in the sample as . Then the estimate is given by
Now we introduce as a control variate with a known expected value and combine the two into a new estimate
Using realizations and an estimated optimal coefficient we obtain the following result |
https://en.wikipedia.org/wiki/Mutual%20authentication | Mutual authentication or two-way authentication (not to be confused with two-factor authentication) refers to two parties authenticating each other at the same time in an authentication protocol. It is a default mode of authentication in some protocols (IKE, SSH) and optional in others (TLS).
Mutual authentication is a desired characteristic in verification schemes that transmit sensitive data, in order to ensure data security. Mutual authentication can be accomplished with two types of credentials: usernames and passwords, and public key certificates.
Mutual authentication is often employed in the Internet of Things (IoT). Writing effective security schemes in IoT systems can become challenging, especially when schemes are desired to be lightweight and have low computational costs. Mutual authentication is a crucial security step that can defend against many adversarial attacks, which otherwise can have large consequences if IoT systems (such as e-Healthcare servers) are hacked. In scheme analyses done of past works, a lack of mutual authentication had been considered a weakness in data transmission schemes.
Process steps and verification
Schemes that have a mutual authentication step may use different methods of encryption, communication, and verification, but they all share one thing in common: each entity involved in the communication is verified. If Alice wants to communicate with Bob, they will both authenticate the other and verify that it is who they are expecting to communicate with before any data or messages are transmitted. A mutual authentication process that exchanges user IDs may be implemented as follows:
Alice sends an encrypted message to Bob to show that Alice is a valid user.
Bob verifies message:
Bob checks the format and timestamp. If either is incorrect or invalid, the session is aborted.
The message is then decrypted with Bob's secret key, giving Alice's ID.
Bob checks if the message matches a valid user. If not, the session is abor |
https://en.wikipedia.org/wiki/Cayley%E2%80%93Bacharach%20theorem | In mathematics, the Cayley–Bacharach theorem is a statement about cubic curves (plane curves of degree three) in the projective plane . The original form states:
Assume that two cubics and in the projective plane meet in nine (different) points, as they do in general over an algebraically closed field. Then every cubic that passes through any eight of the points also passes through the ninth point.
A more intrinsic form of the Cayley–Bacharach theorem reads as follows:
Every cubic curve over an algebraically closed field that passes through a given set of eight points also passes through (counting multiplicities) a ninth point which depends only on .
A related result on conics was first proved by the French geometer Michel Chasles and later generalized to cubics by Arthur Cayley and Isaak Bacharach.
Details
If seven of the points lie on a conic, then the ninth point can be chosen on that conic, since will always contain the whole conic on account of Bézout's theorem. In other cases, we have the following.
If no seven points out of are co-conic, then the vector space of cubic homogeneous polynomials that vanish on (the affine cones of) (with multiplicity for double points) has dimension two.
In that case, every cubic through also passes through the intersection of any two different cubics through , which has at least nine points (over the algebraic closure) on account of Bézout's theorem. These points cannot be covered by only, which gives us .
Since degenerate conics are a union of at most two lines, there are always four out of seven points on a degenerate conic that are collinear. Consequently:
If no seven points out of lie on a non-degenerate conic, and no four points out of lie on a line, then the vector space of cubic homogeneous polynomials that vanish on (the affine cones of) has dimension two.
On the other hand, assume are collinear and no seven points out of are co-conic. Then no five points of and no three points of are colline |
https://en.wikipedia.org/wiki/Tagetes%20erecta | Tagetes erecta, the Aztec marigold, Mexican marigold, big marigold, cempazúchitl or cempasúchil, is a species of flowering plant in the genus Tagetes native to Mexico. Despite being native to the Americas, it is often called the African marigold. In Mexico, this plant is found in the wild in the states of México, Michoacán, Puebla, Veracruz and Guerrero
This plant reaches heights of between . The Aztecs gathered the wild plant as well as cultivating it for medicinal, ceremonial and decorative purposes. It is widely cultivated commercially with many cultivars in use as ornamental plants, and for the cut-flower trade.
Some authorities regard Tagetes patula (the French marigold) as a synonym of Tagetes erecta.
Description
It is a herbaceous annual or perennial plant whose height ranges from 30–110 cm. The root is cylindrical, pivoting, with a fibrous and shallow branching system. The stem is striated, sometimes ridged, smooth or slightly with villi, cylindrical, oval and herbaceous to slightly woody, with resin channels in the bark, which are aromatic when squeezed. Opposite leaves at the bottom alternate at the top, up to 20 cm long, pinnate, composed of 11 to 17 leaflets, lanceolate to linear-lanceolate, up to 5 cm long and 1.5 cm wide, acute to acuminate, serrated to sub-holders, the lower ones of each leaf frequently setiform (in the form of threads), the superiors are sometimes completely setiform; with abundant round glands.
The main characteristic of the flowers is that they are grouped in small heads or in solitary inflorescences, on peduncles up to 15 cm long, they are liguladas of yellow colors to red. In the flowers of the disc: 150 to 250 in the simple heads, in the doubles it shows different degrees of transformation in ligules, yellow to orange corollas, of 8 to 10 mm in length. The fruits and seeds are: linear achenes 7 to 10 mm long, smooth or slightly covered with stiff hairs at the corners. It has a long flowering period extending throughout the s |
https://en.wikipedia.org/wiki/Bacterial%20outer%20membrane | The bacterial outer membrane is found in gram-negative bacteria. Its composition is distinct from that of the inner cytoplasmic cell membrane - among other things, the outer leaflet of the outer membrane of many gram-negative bacteria includes a complex lipopolysaccharide whose lipid portion acts as an endotoxin - and in some bacteria such as E. coli it is linked to the cell's peptidoglycan by Braun's lipoprotein.
Porins can be found in this layer.
Clinical significance
If lipid A, part of the lipopolysaccharide, enters the circulatory system it causes a toxic reaction by activating toll like receptor TLR 4. Lipid A is very pathogenic and not immunogenic. However, the polysaccharide component is very immunogenic, but not pathogenic, causing an aggressive response by the immune system. The sufferer will have a high temperature and respiration rate and a low blood pressure. This may lead to endotoxic shock, which may be fatal. The bacterial outer membrane is physiologically shed as the bounding membrane of outer membrane vesicles in cultures, as well as in animal tissues at the host-pathogen interface, implicated in translocation of gram-negative microbial biochemical signals to host or target cells.
Biogenesis
The biogenesis of the outer membrane requires that the individual components are transported from the site of synthesis to their final destination outside the inner membrane by crossing both hydrophilic and hydrophobic compartments. The machinery and the energy source that drive this process are not yet fully understood. The lipid A-core moiety and the O-antigen repeat units are synthesized at the cytoplasmic face of the inner membrane and are separately exported via two independent transport systems, namely, the O-antigen transporter Wzx (RfbX) and the ATP binding cassette (ABC) transporter MsbA that flips the lipid A-core moiety from the inner leaflet to the outer leaflet of the inner membrane. O-antigen repeat units are then polymerised in the periplasm |
https://en.wikipedia.org/wiki/Hyaline | A hyaline substance is one with a glassy appearance. The word is derived from , and .
Histopathology
Hyaline cartilage is named after its glassy appearance on fresh gross pathology. On light microscopy of H&E stained slides, the extracellular matrix of hyaline cartilage looks homogeneously pink, and the term "hyaline" is used to describe similarly homogeneously pink material besides the cartilage. Hyaline material is usually acellular and proteinaceous. For example, arterial hyaline is seen in aging, high blood pressure, diabetes mellitus and in association with some drugs (e.g. calcineurin inhibitors). It is bright pink with PAS staining.
Ichthyology and entomology
In ichthyology and entomology, hyaline denotes a colorless, transparent substance, such as unpigmented fins of fishes or clear insect wings.
Botany
In botany hyaline refers to thin and translucent plant parts, such as the margins of some sepals, bracts and leaves.
See also
Hyaline arteriolosclerosis
Hyaloid canal, which passes through the eye
Hyalopilitic
Hyaloserositis
Infant respiratory distress syndrome, previously known as hyaline membrane disease |
https://en.wikipedia.org/wiki/Network%20Admission%20Control | Network Admission Control (NAC) refers to Cisco's version of Network Access Control, which restricts access to the network based on identity or security posture. When a network device (switch, router, wireless access point, DHCP server, etc.) is configured for NAC, it can force user or machine authentication prior to granting access to the network. In addition, guest access can be granted to a quarantine area for remediation of any problems that may have caused authentication failure. This is enforced through an inline custom network device, changes to an existing switch or router, or a restricted DHCP class. A typical (non-free) WiFi connection is a form of NAC. The user must present some sort of credentials (or a credit card) before being granted access to the network.
In its initial phase, the Cisco Network Admission Control (NAC) functionality enables Cisco routers to enforce access privileges when an endpoint attempts to connect to a network. This access decision can be on the basis of information about the endpoint device, such as its current antivirus state. The antivirus state includes information such as version of antivirus software, virus definitions, and version of scan engine.
Network admission control systems allow noncompliant devices to be denied access, placed in a quarantined area, or given restricted access to computing resources, thus keeping insecure nodes from infecting the network.
The key component of the Cisco Network Admission Control program is the Cisco Trust Agent, which resides on an endpoint system and communicates with Cisco routers on the network. The Cisco Trust Agent collects security state information, such as what antivirus software is being used, and communicates this information to Cisco routers. The information is then relayed to a Cisco Secure Access Control Server (ACS) where access control decisions are made. The ACS directs the Cisco router to perform enforcement against the endpoint.
This Cisco product has been m |
https://en.wikipedia.org/wiki/Microstate%20%28statistical%20mechanics%29 | In statistical mechanics, a microstate is a specific configuration of a system that describes the precise positions and momenta of all the individual particles or components that make up the system. Each microstate has a certain probability of occurring during the course of the system's thermal fluctuations.
In contrast, the macrostate of a system refers to its macroscopic properties, such as its temperature, pressure, volume and density. Treatments on statistical mechanics define a macrostate as follows: a particular set of values of energy, the number of particles, and the volume of an isolated thermodynamic system is said to specify a particular macrostate of it. In this description, microstates appear as different possible ways the system can achieve a particular macrostate.
A macrostate is characterized by a probability distribution of possible states across a certain statistical ensemble of all microstates. This distribution describes the probability of finding the system in a certain microstate. In the thermodynamic limit, the microstates visited by a macroscopic system during its fluctuations all have the same macroscopic properties.
In a quantum system, the microstate is simply the value of the wave function.
Microscopic definitions of thermodynamic concepts
Statistical mechanics links the empirical thermodynamic properties of a system to the statistical distribution of an ensemble of microstates. All macroscopic thermodynamic properties of a system may be calculated from the partition function that sums of all its microstates.
At any moment a system is distributed across an ensemble of microstates, each labeled by , and having a probability of occupation , and an energy . If the microstates are quantum-mechanical in nature, then these microstates form a discrete set as defined by quantum statistical mechanics, and is an energy level of the system.
Internal energy
The internal energy of the macrostate is the mean over all microstates of the syste |
https://en.wikipedia.org/wiki/Semantide | Semantides (or semantophoretic molecules) are biological macromolecules that carry genetic information or a transcript thereof. Three different categories or semantides are distinguished: primary, secondary and tertiary. Primary Semantides are genes, which consist of DNA. Secondary semantides are chains of messenger RNA, which are transcribed from DNA. Tertiary semantides are polypeptides, which are translated from messenger RNA. In eukaryotic organisms, primary semantides may consist of nuclear, mitochondrial or plastid DNA. Not all primary semantides ultimately form tertiary semantides. Some primary semantides are not transcribed into mRNA (non-coding DNA) and some secondary semantides are not translated into polypeptides (non-coding RNA). The complexity of semantides varies greatly. For tertiary semantides, large globular polypeptide chains are most complex while structural proteins, consisting of repeating simple sequences, are least complex. The term semantide and related terms were coined by Linus Pauling and Emile Zuckerkandl. Although semantides are the major type of data used in modern phylogenetics, the term itself is not commonly used.
Related terms
Isosemantic
DNA or RNA that differs in base sequence, but translate into identical polypeptide chains are referred to as being isosemantic.
Episemantic
Molecules that are synthesized by enzymes (tertiary semantides) are referred to as episemantic molecules. Episemantic molecules have a larger variety in types than semantides, which only consist of three types (DNA, RNA or polypeptides). Not all polypeptides are tertiary semantides. Some, mainly small polypeptides, can also be episemantic molecules.
Asemantic
Molecules that are not produced by an organism are referred to as asemantic molecules, because they do not contain any genetic information. Asementic molecules may be changed into episemantic molecules by anabolic processes. Asemantic molecules may also become semantic molecules when they integrate |
https://en.wikipedia.org/wiki/Nano-ITX | Nano-ITX is a computer motherboard form factor first proposed by VIA Technologies at CeBIT in March 2003, and implemented in late 2005. Nano-ITX boards measure , and are fully integrated, very low power consumption motherboards with many uses, but targeted at smart digital entertainment devices such as DVRs, set-top boxes, media centers, car PCs, and thin devices. Nano-ITX motherboards have slots for SO-DIMM.
There are four Nano-ITX motherboard product lines so far, VIA's EPIA N, EPIA NL, EPIA NX, and the VIA EPIA NR. These boards are available from a wide variety of manufacturers supporting numerous different CPU platforms.
Udoo has now released at least 1 nano-ITX board: the Udoo Bolt.
See also
Mini-ITX
Pico-ITX
Mobile-ITX
EPIA, mini-ITX and nano-ITX motherboards from VIA
Ultra-Mobile PC
Minimig, is an open source re-implementation of an Amiga 500 in Nano-ITX format |
https://en.wikipedia.org/wiki/Heisenberg%27s%20microscope | Heisenberg's microscope is a thought experiment proposed by Werner Heisenberg that has served as the nucleus of some commonly held ideas about quantum mechanics. In particular, it provides an argument for the uncertainty principle on the basis of the principles of classical optics.
The concept was criticized by Heisenberg's mentor Niels Bohr, and theoretical and experimental developments have suggested that Heisenberg's intuitive explanation of his mathematical result might be misleading. While the act of measurement does lead to uncertainty, the loss of precision is less than that predicted by Heisenberg's argument when measured at the level of an individual state. The formal mathematical result remains valid, however, and the original intuitive argument has also been vindicated mathematically when the notion of disturbance is expanded to be independent of any specific state.
Heisenberg's argument
Heisenberg supposes that an electron is like a classical particle, moving in the direction along a line below the microscope. Let the cone of light rays leaving the microscope lens and focusing on the electron make an angle with the electron. Let be the wavelength of the light rays. Then, according to the laws of classical optics, the microscope can only resolve the position of the electron up to an accuracy of
An observer perceives an image of the particle because the light rays strike the particle and bounce back through the microscope to the observer's eye. We know from experimental evidence that when a photon strikes an electron, the latter has a Compton recoil with momentum proportional to , where is Planck's constant. However, the extent of "recoil cannot be exactly known, since the direction of the scattered photon is undetermined within the bundle of rays entering the microscope." In particular, the electron's momentum in the direction is only determined up to
Combining the relations for and , we thus have
,
which is an approximate expression of Hei |
https://en.wikipedia.org/wiki/Jack%20Block | Jacob "Jack" Block (April 28, 1924 – January 13, 2010) was a psychology professor at UC Berkeley. His main areas of research were personality theory, personality development, research methodology, personality assessment, longitudinal research, and cognition. He often collaborated with his wife Jeanne Block.
His most renowned body of work, undertaken primarily with his wife, was a longitudinal study on a cohort of more than 100 San Francisco Bay Area toddlers. He studied them regularly for nearly 30 years. Unlike most longitudinal studies, the Blocks' focused on the psychological makeup and history of the subjects, rather than quantitative measures such as IQ. The study tracked how the subjects' background influenced their later choices and the outcomes of their lives.
Block was born in Brooklyn, New York, and received a bachelor's degree from Brooklyn College. He earned his Ph.D. from Stanford University in 1950. He received many awards over the years and was a fellow of the American Association for the Advancement of Science.
One of Block's studies drew particular notice in the news media. Published in The Journal of Research in Personality in 2006, it found that subjects who at 3 years old had seemed thin-skinned, rigid, inhibited and vulnerable tended at 23 to be political conservatives. On the other hand, 3-year-olds characterized as self-reliant, energetic, somewhat dominating and resilient were inclined to become liberals.
Book publications
"The Q-Sort Method in Personality Assessment and Psychiatric Research", 1961
"The Challenge of Response Sets", 1965
Lives Through Time, 1971
Personality as an Affect-Processing System, 2002
The Q-Sort in Character Appraisal, 2008 |
https://en.wikipedia.org/wiki/European%20Community%20number | The European Community number (EC number) is a unique seven-digit identifier that was assigned to substances for regulatory purposes within the European Union by the European Commission. The EC Inventory comprises three individual inventories, EINECS, ELINCS and the NLP list.
Structure
The EC number may be written in a general form as: NNN-NNN-R, where R is a check digit and N represents integers. The check digit is calculated using the ISBN method. According to this method, the check digit R is the following sum modulo 11:
If the remainder R is equal to 10, that combination of digits is not used for an EC number. To illustrate, the EC number of dexamethasone is 200-003-9. N1 is 2, N2 through N5 are 0, and N6 is 3.
The remainder is 9, which is the check digit.
There is a set of 181 ELINCS numbers (EC numbers starting with 4) for which the checksum by the above algorithm is 10 and the number has not been skipped but issued with a checksum of 1.
EC Inventory
The EC Inventory includes the substances in the following inventories. The content of these inventories is fixed and official.
List numbers
European Chemicals Agency (ECHA) also applies the EC number format to what it calls "List number". The number are assigned under the REACH Regulation without being legally recognised. Hence, they are not official because they have not been published in the Official Journal of the European Union. List numbers are administrative tools only and shall not be used for any official purposes.
See also
Registration, Evaluation, Authorisation and Restriction of Chemicals
European chemical Substances Information System
CAS registry number |
https://en.wikipedia.org/wiki/Quantitative%20psychology | Quantitative psychology is a field of scientific study that focuses on the mathematical modeling, research design and methodology, and statistical analysis of psychological processes. It includes tests and other devices for measuring cognitive abilities. Quantitative psychologists develop and analyze a wide variety of research methods, including those of psychometrics, a field concerned with the theory and technique of psychological measurement.
Psychologists have long contributed to statistical and mathematical analysis, and quantitative psychology is now a specialty recognized by the American Psychological Association. Doctoral degrees are awarded in this field in a number of universities in Europe and North America, and quantitative psychologists have been in high demand in industry, government, and academia. Their training in both social science and quantitative methodology provides a unique skill set for solving both applied and theoretical problems in a variety of areas.
History
Quantitative psychology has its roots in early experimental psychology when, in the nineteenth century, the scientific method was first systematically applied to psychological phenomena. Notable contributions included E. H. Weber's studies of tactile sensitivity (1830s), Fechner's development and use of the psychophysical methods (1850-1860), and Helmholtz's research on vision and audition beginning after 1850. Wilhelm Wundt is often called the "founder of experimental psychology", because he called himself a psychologist and opened a psychological laboratory in 1879 where many researchers came to study. The work of these and many others helped put to rest the assertion, by theorists such as Immanuel Kant, that psychology could not become a science because precise experiments on the human mind were impossible.
Intelligence testing
Intelligence testing has long been an important branch of quantitative psychology. The nineteenth-century English statistician Francis Galton, a pione |
https://en.wikipedia.org/wiki/Chan%20King-ming | Chan King-ming is a Hong Kong politician and academic. He served as the vice-chairman of the Democratic Party of Hong Kong from 2004 to 2006. He is also an associate professor in the department of biochemistry and Environmental Science Program of the Chinese University of Hong Kong.
Academic career
Chan King-ming earned his Bachelor of Science and Master of Philosophy degrees at the Chinese University of Hong Kong, and his doctoral degree from Memorial University of Newfoundland in St. John's, Newfoundland, Canada.
He is now director of the Environmental Science Program at the Chinese University of Hong Kong. He teaches many different courses including Current Environmental Issues, Biochemical Toxicology and Introduction to Environmental Science in the Environmental Science Program and Molecular Endocrinology in the Biochemistry Programme. Trained as a molecular biologist for his PhD and post-doctoral research, Professor Chan's research interests include gene regulation, aquatic toxicology, marine biotechnology and environmental biochemistry and environmental policy. Prof. Chan is also chairman of CUTA (Chinese University Teachers Association), trustee of Shaw College Board of trustees, Member of Assembly of Fellows, Shaw College, and warden of Hostel 2, Shaw College.
Political career
Chan is a founding member of the Democratic Party. He was elected as chairman of the New Territories East Branch in 1999, and later became the party's minister of organization affairs and central committee member. He ran for the chairmanship election in 2004 but lost to Lee Wing-tat. He was then elected vice-chairman of the party. He also served as a part-time member of Central Policy Unit of the Hong Kong Government between 2004 and 2006.
He ran again for the chairmanship in December 2006, but lost to Albert Ho. He did not seek to run for the vice-chairmanship in the 2006 election. In 2010, the Democratic Party decided to support the government's proposal of the political reform |
https://en.wikipedia.org/wiki/Houndstooth | Houndstooth, hounds tooth check or hound's tooth (and similar spellings), also known as dogstooth, dogtooth, dog's tooth, (), (), is a duotone textile pattern characterized by broken checks or abstract four-pointed shapes, traditionally in black and white or such contrasting dark and light pattern.
Design and history
The classic houndstooth pattern is an example of a tessellation. It is a duotone textile pattern characterized by broken checks or abstract four-pointed shapes, traditionally in black and white or such contrasting dark and light pattern, although other colour combinations are also often applied.
The oldest Bronze Age houndstooth textiles found so far are from the Hallstatt Celtic Salt Mine, Austria, 1500-1200 BC. One of the best known early occurrence of houndstooth is the Gerum Cloak, a garment uncovered in a Swedish peat bog, dated to between 360 and 100 BC. Contemporary houndstooth checks may have originated as a pattern in woven tweed cloth from the Scottish Lowlands, but are now used in many other woven fabric aside from wool. The traditional houndstooth check is made with alternating bands of four dark and four light threads in both warp and weft/filling woven in a simple 2:2 twill, two over/two under the warp, advancing one thread each pass. In an early reference to houndstooth, De Pinna, a New York City–based men's and women's high-end clothier founded in 1885, included houndstooth checks along with gun club checks and Scotch plaids as part of its 1933 spring men's suits collection. The actual term houndstooth for the pattern is not recorded before 1936.
Oversized houndstooth patterns were also employed prominently at Alexander McQueen's Fall 2009 Collection, entitled Horn of Plenty. The patterns were a reference to Christian Dior's signature tweed suits.
Houndstooth patterns, especially black-and-white houndstooth, have long been associated regionally with the University of Alabama (UA). This is because the longtime UA football coach Paul " |
https://en.wikipedia.org/wiki/Open%20%28system%20call%29 | For most file systems, a program initializes access to a file in a file system using the open system call. This allocates resources associated to the file (the file descriptor), and returns a handle that the process will use to refer to that file. In some cases the open is performed by the first access.
The same file may be opened simultaneously by several processes, and even by the same process, resulting in several file descriptors for the same file; depending on the file organization and filesystem. Operations on the descriptors such as moving the file pointer or closing it are independentthey do not affect other descriptors for the same file. Operations on the file, such as a write, can be seen by operations on the other descriptors: a later read can read the newly written data.
During the open, the filesystem may allocate memory for buffers, or it may wait until the first operation.
The absolute file path is resolved. This may include connecting to a remote host and notifying an operator that a removable medium is required. It may include the initialization of a communication device. At this point an error may be returned if the host or medium is not available. The first access to at least the directory within the filesystem is performed. An error will usually be returned if the higher level components of the path (directories) cannot be located or accessed. An error will be returned if the file is expected to exist and it does not or if the file should not already exist and it does.
If the file is expected to exist and it does, the file access, as restricted by permission flags within the file meta data or access control list, is validated against the requested type of operations. This usually requires an additional filesystem access although in some filesystems meta-flags may be part of the directory structure.
If the file is being created, the filesystem may allocate the default initial amount of storage or a specified amount depending on the file |
https://en.wikipedia.org/wiki/Section%20%28botany%29 | In botany, a section () is a taxonomic rank below the genus, but above the species. The subgenus, if present, is higher than the section, and the rank of series, if present, is below the section. Sections may in turn be divided into subsections.
Sections are typically used to help organise very large genera, which may have hundreds of species. A botanist wanting to distinguish groups of species may prefer to create a taxon at the rank of section or series to avoid making new combinations, i.e. many new binomial names for the species involved.
Examples:
Lilium sectio Martagon Rchb. are the Turks' cap lilies
Plagiochila aerea Taylor is the type species of Plagiochila sect. Bursatae
See also
Section (biology) |
https://en.wikipedia.org/wiki/Enumerative%20geometry | In mathematics, enumerative geometry is the branch of algebraic geometry concerned with counting numbers of solutions to geometric questions, mainly by means of intersection theory.
History
The problem of Apollonius is one of the earliest examples of enumerative geometry. This problem asks for the number and construction of circles that are tangent to three given circles, points or lines. In general, the problem for three given circles has eight solutions, which can be seen as 23, each tangency condition imposing a quadratic condition on the space of circles. However, for special arrangements of the given circles, the number of solutions may also be any integer from 0 (no solutions) to six; there is no arrangement for which there are seven solutions to Apollonius' problem.
Key tools
A number of tools, ranging from the elementary to the more advanced, include:
Dimension counting
Bézout's theorem
Schubert calculus, and more generally characteristic classes in cohomology
The connection of counting intersections with cohomology is Poincaré duality
The study of moduli spaces of curves, maps and other geometric objects, sometimes via the theory of quantum cohomology. The study of quantum cohomology, Gromov–Witten invariants and mirror symmetry gave a significant progress in Clemens conjecture.
Enumerative geometry is very closely tied to intersection theory.
Schubert calculus
Enumerative geometry saw spectacular development towards the end of the nineteenth century, at the hands of Hermann Schubert. He introduced it for the purpose the Schubert calculus, which has proved of fundamental geometrical and topological value in broader areas. The specific needs of enumerative geometry were not addressed until some further attention was paid to them in the 1960s and 1970s (as pointed out for example by Steven Kleiman). Intersection numbers had been rigorously defined (by André Weil as part of his foundational programme 1942–6, and again subsequently), but this did |
https://en.wikipedia.org/wiki/Sidetone | Sidetone is audible feedback to someone speaking or otherwise producing sound as an indication of active transmission. Sidetone is introduced by some communications circuits and anti-sidetone circuitry is used to control its level.
Sidetone is expected behavior for telephone systems. Absence of sidetone can cause users to believe the call has been dropped or cause them to speak loudly. Too much sidetone can cause users to speak softly.
Telephony
In telephony, sidetone is the effect of sound picked up by the telephone's transmitter (mouthpiece) and instantly introduced at a low electronic signal level into the receiver (earpiece) of the same handset, a form of electrical feedback through the telephone hybrid. Sidetone in early 19th century telephones was strong due to the type of circuit used in instruments. Anti-sidetone circuitry in the telephone hybrid brought sidetone under control in the early 20th century, leaving enough feedback signal to assure the user that the telephone is working.<ref>J. W. Foley, Bell Laboratories Record 17(11) 347 (July 1939) The Anti-Sidetone Station Circuit</ref>
Almost all land-line (wired and wireless) telephones have employed sidetone, so it was an expected convention for cellular telephony, but is not standard. The amount of sidetone on land-lines is typically 8%, and is 4% for cellular phones. Usability experts believe that lack of adequate sidetone causes some people to shout or speak too loudly when using a cell phone, a behavior that is sometimes referred to as "cell yell".
One of the benefits of sidetone-enabled phones is that a user knows a call has been dropped or ended if he or she no longer hears sidetone. Comfort noise provides a similar benefit.
Sidetone is disabled when telephones are running in speakerphone mode to prevent direct acoustical feedback from the speaker to the microphone, resulting in howling. Sidetone can be, and often is, amplified for land-line phones for the hearing impaired.
Radiotelegraphy
In w |
https://en.wikipedia.org/wiki/Opera%20Mini | Opera Mini is a mobile web browser made by Opera. It was primarily designed for the Java ME platform, as a low-end sibling for Opera Mobile, but only the Android build was still under active development. It had previously been developed for iOS, Windows 10 Mobile, Windows Phone 8.1, BlackBerry, Symbian, and Bada.
Opera Mini was derived from the Opera web browser. Opera Mini requests web pages through Opera Software's compression proxy server. The compression server processes and compresses requested web pages before sending them to the mobile phone. The compression ratio is 90% and the transfer speed is increased by two to three times as a result. The pre-processing increases compatibility with web pages not designed for mobile phones. However, interactive sites which depend upon the device processing JavaScript do not work properly.
In July 2012, Opera Software reported that Opera Mini had 168.8 million users as of March 2012. In February 2013, Opera reported 300 million unique Opera Mini active users and 150 billion page views served during that month. This represented an increase of 25 million users from September 2012.
History
Origin
Opera Mini was derived from the Opera web browser for personal computers, which has been publicly available since 1996. Opera Mini was originally intended for use on mobile phones not capable of running a conventional Web browser. It was introduced on 10 August 2005, as a pilot project in cooperation with the Norwegian television station TV 2, and only available to TV 2 customers. The beta version was made available in Sweden, Denmark, Norway, and Finland on 20 October 2005. After the final version was launched in Germany on 10 November 2005, and quietly released to all countries through the Opera Mini website in December, the browser was officially launched worldwide on 24 January 2006.
On 3 May 2006, Opera Mini 2.0 was released. It included new features such as the ability to download files, new custom skins, more search eng |
https://en.wikipedia.org/wiki/Line%20spectral%20pairs | Line spectral pairs (LSP) or line spectral frequencies (LSF) are used to represent linear prediction coefficients (LPC) for transmission over a channel. LSPs have several properties (e.g. smaller sensitivity to quantization noise) that make them superior to direct quantization of LPCs. For this reason, LSPs are very useful in speech coding.
LSP representation was developed by Fumitada Itakura, at Nippon Telegraph and Telephone (NTT) in 1975. From 1975 to 1981, he studied problems in speech analysis and synthesis based on the LSP method. In 1980, his team developed an LSP-based speech synthesizer chip. LSP is an important technology for speech synthesis and coding, and in the 1990s was adopted by almost all international speech coding standards as an essential component, contributing to the enhancement of digital speech communication over mobile channels and the internet worldwide. LSPs are used in the code-excited linear prediction (CELP) algorithm, developed by Bishnu S. Atal and Manfred R. Schroeder in 1985.
Mathematical foundation
The LP polynomial can be expressed as , where:
By construction, P is a palindromic polynomial and Q an antipalindromic polynomial; physically P(z) corresponds to the vocal tract with the glottis closed and Q(z) with the glottis open. It can be shown that:
The roots of P and Q lie on the unit circle in the complex plane.
The roots of P alternate with those of Q as we travel around the circle.
As the coefficients of P and Q are real, the roots occur in conjugate pairs
The Line Spectral Pair representation of the LP polynomial consists simply of the location of the roots of P and Q (i.e. such that ). As they occur in pairs, only half of the actual roots (conventionally between 0 and ) need be transmitted. The total number of coefficients for both P and Q is therefore equal to p, the number of original LP coefficients (not counting ).
A common algorithm for finding these is to evaluate the polynomial at a sequence of closely |
https://en.wikipedia.org/wiki/Retirement%20annuity%20plan | Retirement annuity plan is a financial product that ensures regular income to retirees in later years most often issued and distributed (or sold) by an insurance organization. The main idea behind this product is to provide retirees the opportunity to attain income after retirement. A 'Retirement annuity plan (RAP) is a type of retirement plan similar to IRA that provides a stream of regular (single) distributions to an insured retiree. Time intervals between distributions as well as their amount are defined by conditions and type of the annuity between issuer organization and client. Nowadays many types of retirement annuities are offered on the market.
Accumulation & Distribution Phase
Accumulation Phase
The Accumulation Phase of a retirement plan is a period of an individual's life in which they are working and are able to save money for retirement. The accumulation phase begins when an individual starts to save money for retirement and ends when they start to receive distributions.
When individuals decide to buy an annuity they agree to pay a lump upfront or to make regular deposits to the insurance institution. The money individuals pay to the insurance companies is then reinvested into the market. Money grows until the day when an individual decides to retire.
Distribution (Payback) Phase
The payback phase starts as soon as distributions are paid to the insured individuals. There are different ways how insurance organizations can distribute payments. Payments could be distributed for a predetermined period of time (e. g. 15 years) annually, semi-annually, etc.; as well as in the form of a life annuity or a single payment. Payments could be paid immediately after the retirement of an individual or after some period of time.
Types of Retirement Annuities and their differences
Fixed vs. Variable Retirement Annuity
Individuals that enter into a fixed annuity have the opportunity to decide ahead of time how much they will receive when the distribution phas |
https://en.wikipedia.org/wiki/Non-functional%20requirement | In systems engineering and requirements engineering, a non-functional requirement (NFR) is a requirement that specifies criteria that can be used to judge the operation of a system, rather than specific behaviours. They are contrasted with functional requirements that define specific behavior or functions. The plan for implementing functional requirements is detailed in the system design. The plan for implementing non-functional requirements is detailed in the system architecture, because they are usually architecturally significant requirements.
Definition
Broadly, functional requirements define what a system is supposed to do and non-functional requirements define how a system is supposed to be. Functional requirements are usually in the form of "system shall do <requirement>", an individual action or part of the system, perhaps explicitly in the sense of a mathematical function, a black box description input, output, process and control functional model or IPO Model. In contrast, non-functional requirements are in the form of "system shall be <requirement>", an overall property of the system as a whole or of a particular aspect and not a specific function. The system's overall properties commonly mark the difference between whether the development project has succeeded or failed.
Non-functional requirements are often called the "quality attributes" of a system. Other terms for non-functional requirements are "qualities", "quality goals", "quality of service requirements", "constraints", "non-behavioral requirements", or "technical requirements". Informally these are sometimes called the "ilities", from attributes like stability and portability. Qualities—that is non-functional requirements—can be divided into two main categories:
Execution qualities, such as safety, security and usability, which are observable during operation (at run time).
Evolution qualities, such as testability, maintainability, extensibility and scalability, which are embodied in the |
https://en.wikipedia.org/wiki/Electrolyte%E2%80%93insulator%E2%80%93semiconductor%20sensor | Within electronics, an Electrolyte–insulator–semiconductor (EIS) sensor is a sensor that is made of these three components:
an electrolyte with the chemical that should be measured
an insulator that allows field-effect interaction, without leak currents between the two other components
a semiconductor to register the chemical changes
The EIS sensor can be used in combination with other structures, for example to construct a light-addressable potentiometric sensor (LAPS). |
https://en.wikipedia.org/wiki/Achondrogenesis%20type%201B | Achondrogenesis, type 1B is a severe autosomal recessive skeletal disorder, invariably fatal in the perinatal period. It is characterized by extremely short limbs, a narrow chest and a prominent, rounded abdomen. The fingers and toes are short and the feet may be rotated inward. Affected infants frequently have a soft out-pouching around the belly-button (an umbilical hernia) or near the groin (an inguinal hernia).
Achondrogenesis, type 1B is a rare genetic disorder; its incidence is unknown. Achondrogenesis, type 1B is the most severe condition in a spectrum of skeletal disorders caused by mutations in the SLC26A2 gene. This gene provides instructions for making a protein that is essential for the normal development of cartilage and for its conversion to bone. Mutations in the SLC26A2 gene disrupt the structure of developing cartilage, preventing bones from forming properly and resulting in the skeletal problems characteristic of achondrogenesis, type 1B.
Achondrogenesis, type 1B is inherited in an autosomal recessive pattern, which means two copies of the gene in each cell are altered. Most often, the parents of an individual with an autosomal recessive disorder are carriers of one copy of the altered gene but do not show signs and symptoms of the disorder.
See also
Diastrophic dysplasia
Achondrogenesis type 1A |
https://en.wikipedia.org/wiki/RNSAP | RNSAP (Radio Network Subsystem Application Part) is a 3GPP signalling protocol responsible for communications between RNCs Radio Network Controllers defined in 3GPP specification TS 25.423. It is carried on the lur interface and provides functionality needed for soft handovers and SRNS (Serving Radio Network Subsystem) relocation (handoff between RNCs). It defines signalling between RNCs, including SRNC (Serving RNC) and DRNC (drift RNC).
SRNC | DRNC
| IUR |
RNSAP | RNSAP
| | |
Converge protol | Converge protol
| | |
AAL 5 | AAL5
ATM | ATM
Physical links------→→→ Physical links
RNSAP Layer Architecture
Procedures
RNSAP Basic Mobility Procedures-
This set of procedures is used to handle mobility with in the UTRAN.This is the most important of the RNSAP procedures. The
procedures belonging to this set includes SRNC relocation, inter-RNC cell update and UTRAN registration area update.
RNSAP DCH procedures-
This set of procedure used to handle dedicated channel traffic (it includes DCH, DSCH and TDD USCH) between two RNCs. Unlike the basic mobility procedures which is used only for signalling, this set of procedures provides support for data transfer over the Iur interface. The data transfer takes place using a frame protocol. The procedures belonging to this set include establishment, modification and release of dedicated channel in the DRNC due to hard and soft handover, set-up/release of dedicated transport connections over Iur interface and data transfer for dedicated channels.
RNSAP Common Transport Channel Procedures-
This set of procedures is used to handle common and shared channel traffic (it excludes DCH, DSCH and TDD USCH) between two RNCs. In particular, this set of procedures facilitates the set-up and release of common channel transport |
https://en.wikipedia.org/wiki/CHAIN%20%28industry%20standard%29 | The CECED Convergence Working Group has defined a new platform, called CHAIN (Ceced Home Appliances Interoperating
Network), which defines a protocol for interconnecting different home appliances in a single multibrand system.
It allows for control and automation of all basic appliance-related services in a home: e.g., remote control of appliance operation, energy or load management, remote diagnostics and automatic maintenance support to appliances, downloading and updating of data, programs and services (possibly from the Internet).
See also
CECED
KNX/EIB
LonWorks
OSGi
Home automation
Interoperability
ja:欧州家電機器委員会#CHAIN |
https://en.wikipedia.org/wiki/Software%20visualization | Software visualization or software visualisation refers to the visualization of information of and related to software systems—either the architecture of its source code or metrics of their runtime behavior—and their development process by means of static, interactive or animated 2-D or 3-D visual representations of their structure, execution, behavior, and evolution.
Software system information
Software visualization uses a variety of information available about software systems. Key information categories include:
implementation artifacts such as source codes,
software metric data from measurements or from reverse engineering,
traces that record execution behavior,
software testing data (e.g., test coverage)
software repository data that tracks changes.
Objectives
The objectives of software visualization are to support the understanding of software systems (i.e., its structure) and algorithms (e.g., by animating the behavior of sorting algorithms) as well as the analysis and exploration of software systems and their anomalies (e.g., by showing classes with high coupling) and their development and evolution. One of the strengths of software visualization is to combine and relate information of software systems that are not inherently linked, for example by projecting code changes onto software execution traces.
Software visualization can be used as tool and technique to explore and analyze software system information, e.g., to discover anomalies similar to the process of visual data mining. For example, software visualization is used to monitoring activities such as for code quality or team activity. Visualization is not inherently a method for software quality assurance. Software visualization participates to Software Intelligence in allowing to discover and take advantage of mastering inner components of software systems.
Types
Tools for software visualization might be used to visualize source code and quality defects during software development an |
https://en.wikipedia.org/wiki/Stem-cell%20line | A stem cell line is a group of stem cells that is cultured in vitro and can be propagated indefinitely. Stem cell lines are derived from either animal or human tissues and come from one of three sources: embryonic stem cells, adult stem cells, or induced stem cells. They are commonly used in research and regenerative medicine.
Properties
By definition, stem cells possess two properties: (1) they can self-renew, which means that they can divide indefinitely while remaining in an undifferentiated state; and (2) they are pluripotent or multipotent, which means that they can differentiate to form specialized cell types. Due to the self-renewal capacity of stem cells, a stem cell line can be cultured in vitro indefinitely.
A stem-cell line is distinctly different from an immortalized cell line, such as the HeLa line. While stem cells can propagate indefinitely in culture due to their inherent properties, immortalized cells would not normally divide indefinitely but have gained this ability due to mutation. Immortalized cell lines can be generated from cells isolated from tumors, or mutations can be introduced to make the cells immortal.
A stem cell line is also distinct from primary cells. Primary cells are cells that have been isolated and then used immediately. Primary cells cannot divide indefinitely and thus cannot be cultured for long periods of time in vitro.
Types and methods of derivation
Embryonic stem cell line
An embryonic stem cell line is created from cells derived from the inner cell mass of a blastocyst, an early stage, pre-implantation embryo. In humans, the blastocyst stage occurs 4–5 days post fertilization. To create an embryonic stem cell line, the inner cell-mass is removed from the blastocyst, separated from the trophoectoderm, and cultured on a layer of supportive cells in vitro. In the derivation of human embryonic stem cell lines, embryos left over from in vitro fertilization (IVF) procedures are used. The fact that the blastocyst is dest |
https://en.wikipedia.org/wiki/Nat%20%28unit%29 | The natural unit of information (symbol: nat), sometimes also nit or nepit, is a unit of information or information entropy, based on natural logarithms and powers of e, rather than the powers of 2 and base 2 logarithms, which define the shannon. This unit is also known by its unit symbol, the nat. One nat is the information content of an event when the probability of that event occurring is 1/e.
One nat is equal to shannons ≈ 1.44 Sh or, equivalently, hartleys ≈ 0.434 Hart.
History
Boulton and Wallace used the term nit in conjunction with minimum message length, which was subsequently changed by the minimum description length community to nat to avoid confusion with the nit used as a unit of luminance.
Alan Turing used the natural ban.
Entropy
Shannon entropy (information entropy), being the expected value of the information of an event, is inherently a quantity of the same type and with a unit of information. The International System of Units, by assigning the same unit (joule per kelvin) both to heat capacity and to thermodynamic entropy implicitly treats information entropy as a quantity of dimension one, with . Systems of natural units that normalize the Boltzmann constant to 1 are effectively measuring thermodynamic entropy with the nat as unit.
When the shannon entropy is written using a natural logarithm,
it is implicitly giving a number measured in nats.
Notes |
https://en.wikipedia.org/wiki/Ternary%20Golay%20code | In coding theory, the ternary Golay codes are two closely related error-correcting codes.
The code generally known simply as the ternary Golay code is an -code, that is, it is a linear code over a ternary alphabet; the relative distance of the code is as large as it possibly can be for a ternary code, and hence, the ternary Golay code is a perfect code.
The extended ternary Golay code is a [12, 6, 6] linear code obtained by adding a zero-sum check digit to the [11, 6, 5] code.
In finite group theory, the extended ternary Golay code is sometimes referred to as the ternary Golay code.
Properties
Ternary Golay code
The ternary Golay code consists of 36 = 729 codewords.
Its parity check matrix is
Any two different codewords differ in at least 5 positions.
Every ternary word of length 11 has a Hamming distance of at most 2 from exactly one codeword.
The code can also be constructed as the quadratic residue code of length 11 over the finite field F3 (i.e., the Galois Field GF(3) ).
Used in a football pool with 11 games, the ternary Golay code corresponds to 729 bets and guarantees exactly one bet with at most 2 wrong outcomes.
The set of codewords with Hamming weight 5 is a 3-(11,5,4) design.
The generator matrix given by Golay (1949, Table 1.) is
The automorphism group of the (original) ternary Golay code is the Mathieu group M11, which is the smallest of the sporadic simple groups.
Extended ternary Golay code
The complete weight enumerator of the extended ternary Golay code is
The automorphism group of the extended ternary Golay code is 2.M12, where M12 is the Mathieu group M12.
The extended ternary Golay code can be constructed as the span of the rows of a Hadamard matrix of order 12 over the field F3.
Consider all codewords of the extended code which have just six nonzero digits. The sets of positions at which these nonzero digits occur form the Steiner system S(5, 6, 12).
A generator matrix for the extended ternary Golay code is
The corresponding par |
https://en.wikipedia.org/wiki/Cardiac%20skeleton | In cardiology, the cardiac skeleton, also known as the fibrous skeleton of the heart, is a high-density homogeneous structure of connective tissue that forms and anchors the valves of the heart, and influences the forces exerted by and through them. The cardiac skeleton separates and partitions the atria (the smaller, upper two chambers) from the ventricles (the larger, lower two chambers).The heart's cardiac skeleton comprises four dense connective tissue rings that encircle the mitral and tricuspid atrioventricular (AV) canals and extend to the origins of the pulmonary trunk and aorta. This provides crucial support and structure to the heart while also serving to electrically isolate the atria from the ventricles.
The unique matrix of connective tissue within the cardiac skeleton isolates electrical influence within these defined chambers. In normal anatomy, there is only one conduit for electrical conduction from the upper chambers to the lower chambers, known as the atrioventricular node. The physiologic cardiac skeleton forms a firewall governing autonomic/electrical influence until bordering the bundle of His which further governs autonomic flow to the bundle branches of the ventricles. Understood as such, the cardiac skeleton efficiently centers and robustly funnels electrical energy from the atria to the ventricles.
Structure
The structure of the components of the heart has become an area of increasing interest. The cardiac skeleton binds several bands of dense connective tissue, as collagen, that encircle the bases of the pulmonary trunk, aorta, and all four heart valves. While not a traditionally or "true" or rigid skeleton, it does provide structure and support for the heart, as well as isolate the atria from the ventricles. This is why atrial fibrillation almost never degrades to ventricular fibrillation. In youth, this collagen structure is free of calcium adhesions and is quite flexible. With aging, calcium and other mineral accumulation occur withi |
https://en.wikipedia.org/wiki/Gravitational%20acceleration | In physics, gravitational acceleration is the acceleration of an object in free fall within a vacuum (and thus without experiencing drag). This is the steady gain in speed caused exclusively by the force of gravitational attraction. All bodies accelerate in vacuum at the same rate, regardless of the masses or compositions of the bodies; the measurement and analysis of these rates is known as gravimetry.
At a fixed point on the surface, the magnitude of Earth's gravity results from combined effect of gravitation and the centrifugal force from Earth's rotation. At different points on Earth's surface, the free fall acceleration ranges from , depending on altitude, latitude, and longitude. A conventional standard value is defined exactly as 9.80665 m/s² (about 32.1740 ft/s²). Locations of significant variation from this value are known as gravity anomalies. This does not take into account other effects, such as buoyancy or drag.
Relation to the Universal Law
Newton's law of universal gravitation states that there is a gravitational force between any two masses that is equal in magnitude for each mass, and is aligned to draw the two masses toward each other. The formula is:
where and are any two masses, is the gravitational constant, and is the distance between the two point-like masses.
Using the integral form of Gauss's Law, this formula can be extended to any pair of objects of which one is far more massive than the other — like a planet relative to any man-scale artifact. The distances between planets and between the planets and the Sun are (by many orders of magnitude) larger than the sizes of the sun and the planets. In consequence both the sun and the planets can be considered as point masses and the same formula applied to planetary motions. (As planets and natural satellites form pairs of comparable mass, the distance 'r' is measured from the common centers of mass of each pair rather than the direct total distance between planet centers.)
If one |
https://en.wikipedia.org/wiki/Giant%20cell | A giant cell (also known as a multinucleated giant cell, or multinucleate giant cell) is a mass formed by the union of several distinct cells (usually histiocytes), often forming a granuloma. Although there is typically a focus on the pathological aspects of multinucleate giant cells (MGCs), they also play many important physiological roles. Osteoclasts are a type of MGC that are critical for the maintenance, repair, and remodeling of bone and are present normally in a healthy human body. Osteoclasts are frequently classified and discussed separately from other MGCs which are more closely linked with disease.
Non-osteoclast MGCs can arise in response to an infection, such as tuberculosis, herpes, or HIV, or as part of a foreign body reaction. These MGCs are cells of monocyte or macrophage lineage fused together. Similar to their monocyte precursors, they can phagocytose foreign materials. However, their large size and extensive membrane ruffling make them better equipped to clear up larger particles. They utilize activated CR3s to ingest complement-opsonized targets. Non-osteoclast MGCs are also responsible for the clearance of cell debris, which is necessary for tissue remodeling after injuries.
Types include foreign-body giant cells, Langhans giant cells, Touton giant cells, Giant-cell arteritis, and Reed–Sternberg cells.
History
Osteoclasts were discovered in 1873. However, it wasn't until the development of the organ culture in the 1970s that their origin and function could be deduced. Although there was a consensus early on about the physiological function of osteoclasts, theories on their origins were heavily debated. Many believed osteoclasts and osteoblasts came from the same progenitor cell. Because of this, osteoclasts were thought to be derived from cells in connective tissue. Studies that observed that bone resorption could be restored by bone marrow and spleen transplants helped prove osteoclasts' hematopoietic origin.
Other multinucleated giant ce |
https://en.wikipedia.org/wiki/Theta%20wave | Theta waves generate the theta rhythm, a neural oscillation in the brain that underlies various aspects of cognition and behavior, including learning, memory, and spatial navigation in many animals. It can be recorded using various electrophysiological methods, such as electroencephalogram (EEG), recorded either from inside the brain or from electrodes attached to the scalp.
At least two types of theta rhythm have been described. The hippocampal theta rhythm is a strong oscillation that can be observed in the hippocampus and other brain structures in numerous species of mammals including rodents, rabbits, dogs, cats, and marsupials. "Cortical theta rhythms" are low-frequency components of scalp EEG, usually recorded from humans. Theta rhythms can be quantified using quantitative electroencephalography (qEEG) using freely available toolboxes, such as, EEGLAB or the Neurophysiological Biomarker Toolbox (NBT).
In rats, theta wave rhythmicity is easily observed in the hippocampus, but can also be detected in numerous other cortical and subcortical brain structures. Hippocampal theta waves, with a frequency range of 6–10 Hz, appear when a rat is engaged in active motor behavior such as walking or exploratory sniffing, and also during REM sleep. Theta waves with a lower frequency range, usually around 6–7 Hz, are sometimes observed when a rat is motionless but alert. When a rat is eating, grooming, or sleeping, the hippocampal EEG usually shows a non-rhythmic pattern known as large irregular activity or LIA. The hippocampal theta rhythm depends critically on projections from the medial septal area, which in turn receives input from the hypothalamus and several brainstem areas. Hippocampal theta rhythms in other species differ in some respects from those in rats. In cats and rabbits, the frequency range is lower (around 4–6 Hz), and theta is less strongly associated with movement than in rats. In bats, theta appears in short bursts associated with echolocation.
|
https://en.wikipedia.org/wiki/Fossorial | A fossorial () animal is one adapted to digging which lives primarily, but not solely, underground. Some examples are badgers, naked mole-rats, clams, meerkats, and mole salamanders, as well as many beetles, wasps, bees and spiders.
Prehistoric evidence
The physical adaptation of fossoriality is widely accepted as being widespread among many prehistoric phyla and taxa, such as bacteria and early eukaryotes. Furthermore, fossoriality has evolved independently multiple times, even within a single family. Fossorial animals appeared simultaneously with the colonization of land by arthropods in the late Ordovician period (over 440 million years ago). Other notable early burrowers include Eocaecilia and possibly Dinilysia. The oldest example of burrowing in synapsids, the lineage which includes modern mammals and their ancestors, is a cynodont, Thrinaxodon liorhinus, found in the Karoo of South Africa, estimated to be 251 million years old. Evidence shows that this adaptation occurred due to dramatic mass extinctions in the Permian period.
Physical adaptations in vertebrates
There are six major external modifications, as described by H. W. Shimer in 1903, that are shared in all mammalian burrowing species:
Fusiform, a spindle-shaped body tapering at both ends, adapted for the dense subsurface environment.
Lesser developed or missing eyesight, considering subsurface darkness.
Small or missing external ears, to reduce naturally occurring friction during burrowing.
Short and stout limbs, since swiftness or speed of movement is less important than the strength to dig.
Broad and stout forelimbs (manus), including long claws, designed to loosen the burrowing material for the hind feet to disperse in the back. This trait is disputed by Jorge Cubo, who states that the skull is the main tool during excavation, but that the most active parts are the forelimbs for digging and that the hind-limbs are used for stability.
Short or missing tail, which has little to no l |
https://en.wikipedia.org/wiki/Photon%20sphere | A photon sphere or photon circle is an area or region of space where gravity is so strong that photons are forced to travel in orbits, which is also sometimes called the last photon orbit. The radius of the photon sphere, which is also the lower bound for any stable orbit, is, for a Schwarzschild black hole,
where is the gravitational constant, is the mass of the black hole, is the speed of light in vacuum, and is the Schwarzschild radius (the radius of the event horizon); see below for a derivation of this result.
This equation entails that photon spheres can only exist in the space surrounding an extremely compact object (a black hole or possibly an "ultracompact" neutron star).
The photon sphere is located farther from the center of a black hole than the event horizon. Within a photon sphere, it is possible to imagine a photon that's emitted from the back of one's head, orbiting the black hole, only then to be intercepted by the person's eyes, allowing one to see the back of the head.
For non-rotating black holes, the photon sphere is a sphere of radius 3/2 rs. There are no stable free-fall orbits that exist within or cross the photon sphere. Any free-fall orbit that crosses it from the outside spirals into the black hole. Any orbit that crosses it from the inside escapes to infinity or falls back in and spirals into the black hole. No unaccelerated orbit with a semi-major axis less than this distance is possible, but within the photon sphere, a constant acceleration will allow a spacecraft or probe to hover above the event horizon.
Another property of the photon sphere is centrifugal force (note: not centripetal) reversal. Outside the photon sphere, the faster one orbits, the greater the outward force one feels. Centrifugal force falls to zero at the photon sphere, including non-freefall orbits at any speed, i.e. an object weighs the same no matter how fast it orbits, and becomes negative inside it. Inside the photon sphere, faster orbiting leads to g |
https://en.wikipedia.org/wiki/Vladimir%20Levenshtein | Vladimir Iosifovich Levenshtein (; 20 May 1935 – 6 September 2017) was a Russian and Soviet scientist who did research in information theory, error-correcting codes, and combinatorial design. Among other contributions, he is known for the Levenshtein distance and a Levenshtein algorithm, which he developed in 1965.
He graduated from the Department of Mathematics and Mechanics of Moscow State University in 1958 and worked at the Keldysh Institute of Applied Mathematics in Moscow ever since. He was a fellow of the IEEE Information Theory Society.
He received the IEEE Richard W. Hamming Medal in 2006, for "contributions to the theory of error-correcting codes and information theory, including the Levenshtein distance".
Life
Levenshtein graduated from Moscow State University in 1958, where he studied in the faculty of Mechanics and Mathematics. After graduation he worked at the M.V Keldysh Institute of Applied Mathematics.
Publications
V.I. Levenshtein, Application of Hadamard matrices to a problem in coding theory, Problems of Cybernetics, vol. 5, GIFML, Moscow, 1961, 125–136.
V.I. Levenshtein, On the stable extension of finite automata, Problems of Cybernetics, vol. 10, GIFML, Moscow, 1963, 281–286.
V.I. Levenshtein, On some coding systems and self-tuning machines for decoding messages, Problems of Cybernetics, vol. 11, GIFML, Moscow, 1964, 63–121.
V.I. Levenshtein, Decoding automata invariant with respect to the initial state, Problems of Cybernetics, vol. 12, GIFML, Moscow, 1964, 125–136.
V.I. Levenshtein, Binary codes providing synchronization and correction of errors, Abstracts of short scientific reports of the International Congress of Mathematicians, Section 13, Moscow, 1966, 24.
V.I. Levenshtein, Asymptotically optimal binary code with correction of occurrences of one or two adjacent characters, Problems of Cybernetics, vol. 19, Science, Moscow, 1967, 293–298.
V.I. Levenshtein, On the redundancy and deceleration of separable c |
https://en.wikipedia.org/wiki/Patch%20panel | A patch panel is a device or unit featuring a number of jacks, usually of the same or similar type, for the use of connecting and routing circuits for monitoring, interconnecting, and testing circuits in a convenient, flexible manner. Patch panels are commonly used in computer networking, recording studios, and radio and television.
The term patch came from early use in telephony and radio studios, where extra equipment kept on standby could be temporarily substituted for failed devices. This reconnection was done via patch cords and patch panels, like the jack fields of cord-type telephone switchboards.
Terminology
Patch panels are also referred to as patch bays, patch fields, jack panels or jack fields.
Uses and connectors
In recording studios, television and radio broadcast studios, and concert sound reinforcement systems, patchbays are widely used to facilitate the connection of different devices, such as microphones, electric or electronic instruments, effects (e.g. compression, reverb, etc.), recording gear, amplifiers, or broadcasting equipment. Patchbays make it easier to connect different devices in different orders for different projects, because all of the changes can be made at the patchbay. Additionally, patchbays make it easier to troubleshoot problems such as ground loops; even small home studios and amateur project studios often use patchbays, because it groups all of the input jacks into one location. This means that devices mounted in racks or keyboard instruments can be connected without having to hunt around behind the rack or instrument with a flashlight for the right jack. Using a patchbay also saves wear and tear on the input jacks of studio gear and instruments, because all of the connections are made with the patchbay.
Patch panels are being used more prevalently in domestic installations, owing to the popularity of "Structured Wiring" installs. They are also found in home cinema installations more and more.
Normalization
It is convent |
https://en.wikipedia.org/wiki/Agitator%20%28device%29 | An agitator is a device or mechanism to put something into motion by shaking or stirring. There are several types of agitation machines, including washing machine agitators (which rotate back and forth) and magnetic agitators (which contain a magnetic bar rotating in a magnetic field). Agitators can come in many sizes and varieties, depending on the application.
In general, agitators usually consist of an impeller and a shaft. An impeller is a rotor located within a tube or conduit attached to the shaft. It helps enhance the pressure in order for the flow of a fluid be done. Modern industrial agitators incorporate process control to maintain better control over the mixing process.
Washing machine agitator
In a top load washing machine the agitator projects from the bottom of the wash basket and creates the wash action by rotating back and forth, rolling garments from the top of the load, down to the bottom, then back up again.
There are several types of agitators with the most common being the "straight-vane" and "dual-action" agitators. The "straight-vane" is a one-part agitator with bottom and side fins that usually turns back and forth. The Dual-action is a two-part agitator that has bottom washer fins that move back and forth and a spiral top that rotates clockwise to help guide the clothes to the bottom washer fins.
The modern agitator, which is dual-action, was first made in Kenmore Appliances washing machines in the 1980s to present. These agitators are known by the company as dual-rollover and triple-rollover action agitators.
Magnetic agitator
This is a device formed by a metallic bar (called the agitation bar) which is normally covered by a plastic layer, and a sheet that has underneath it a rotatory magnet or a series of electromagnets arranged in a circular form to create a magnetic rotatory field. Commonly, the sheet has an arrangement of electric resistances that can heat some chemical solutions.
During the operation of a typical magnetic agita |
https://en.wikipedia.org/wiki/Orthometric%20height | The orthometric height is the vertical distance H along the plumb line from a point of interest to a reference surface known as the geoid, the vertical datum that approximates mean sea level. Orthometric height is one of the scientific formalizations of a laypersons' "height above sea level", along with other types of heights in Geodesy.
In the US, the current NAVD88 datum is tied to a defined elevation at one point rather than to any location's exact mean sea level. Orthometric heights are usually used in the US for engineering work, although dynamic height may be chosen for large-scale hydrological purposes. Heights for measured points are shown on National Geodetic Survey data sheets, data that was gathered over many decades by precise spirit leveling over thousands of miles.
Alternatives to orthometric height include dynamic height and normal height, and various countries may choose to operate with those definitions instead of orthometric. They may also adopt slightly different but similar definitions for their reference surface.
Since gravity is not constant over large areas the orthometric height of a level surface (equipotential) other than the reference surface is not constant, and orthometric heights need to be corrected for that effect. For example, gravity is 0.1% stronger in the northern United States than in the southern, so a level surface that has an orthometric height of 1000 meters in one place will be 1001 meters high in other places. In fact, dynamic height is the most appropriate height measure when working with the level of water over a large geographic area.
Orthometric heights may be obtained from differential leveling height differences by correcting for gravity variations.
Practical applications must use a model rather than measurements to calculate the change in gravitational potential versus depth in the earth, since the geoid is below most of the land surface (e.g., the Helmert orthometric heights of NAVD88).
GPS measurements give |
https://en.wikipedia.org/wiki/363%20%28number%29 | 363 (three hundred [and] sixty-three) is the natural number following 362 and preceding 364.
In mathematics
It is an odd, composite, positive, real integer, composed of a prime (3) and a prime squared (112).
363 is a deficient number and a perfect totient number.
363 is a palindromic number in bases 3, 10, 11 and 32.
363 is a repdigit (BB) in base 32.
The Mertens function returns 0.
Any subset of its digits is divisible by three.
363 is the sum of nine consecutive primes (23 + 29 + 31 + 37 + 41 + 43 + 47 + 53 + 59).
363 is the sum of five consecutive powers of 3 (3 + 9 + 27 + 81 + 243).
363 can be expressed as the sum of three squares in four different ways: 112 + 112 + 112, 52 + 72 + 172, 12 + 12 + 192, and 132 + 132 + 52.
363 cubits is the solution given to Rhind Mathematical Papyrus question 50 – find the side length of an octagon with the same area as a circle 9 khet in diameter . |
https://en.wikipedia.org/wiki/Elliptic%20surface | In mathematics, an elliptic surface is a surface that has an elliptic fibration, in other words a proper morphism with connected fibers to an algebraic curve such that almost all fibers are smooth curves of genus 1. (Over an algebraically closed field such as the complex numbers, these fibers are elliptic curves, perhaps without a chosen origin.) This is equivalent to the generic fiber being a smooth curve of genus one. This follows from proper base change.
The surface and the base curve are assumed to be non-singular (complex manifolds or regular schemes, depending on the context). The fibers that are not elliptic curves are called the singular fibers and were classified by Kunihiko Kodaira. Both elliptic and singular fibers are important in string theory, especially in F-theory.
Elliptic surfaces form a large class of surfaces that contains many of the interesting examples of surfaces, and are relatively well understood in the theories of complex manifolds and smooth 4-manifolds. They are similar to (have analogies with, that is), elliptic curves over number fields.
Examples
The product of any elliptic curve with any curve is an elliptic surface (with no singular fibers).
All surfaces of Kodaira dimension 1 are elliptic surfaces.
Every complex Enriques surface is elliptic, and has an elliptic fibration over the projective line.
Kodaira surfaces
Dolgachev surfaces
Shioda modular surfaces
Kodaira's table of singular fibers
Most of the fibers of an elliptic fibration are (non-singular) elliptic curves. The remaining fibers are called singular fibers: there are a finite number of them, and each one consists of a union of rational curves, possibly with singularities or non-zero multiplicities (so the fibers may be non-reduced schemes). Kodaira and Néron independently classified the possible fibers, and Tate's algorithm can be used to find the type of the fibers of an elliptic curve over a number field.
The following table lists the possible fibers of a minimal el |
https://en.wikipedia.org/wiki/Why%27s%20%28poignant%29%20Guide%20to%20Ruby | why's (poignant) Guide to Ruby, sometimes called w(p)GtR or just "the poignant guide", is an introductory book to the Ruby programming language, written by why the lucky stiff. The book is distributed under the Creative Commons Attribution-ShareAlike license.
The book is unusual among programming books in that it includes much strange humor and many narrative side tracks which are sometimes completely unrelated to the topic. Many motifs have become inside jokes in the Ruby community, such as references to the words "chunky bacon". The book includes many characters which have become popular as well, particularly the cartoon foxes and Trady Blix, a large black feline friend of why's, who acts as a guide to the foxes (and occasionally teaches them some Ruby).
The book is published in HTML and PDF. Chapter three was reprinted in The Best Software Writing I: Selected and Introduced by Joel Spolsky (Apress, 2005).
Contents
About this book
Kon'nichi wa, Ruby
A Quick (and Hopefully Painless) Ride Through Ruby (with Cartoon Foxes): basic introduction to central Ruby concepts
Floating Little Leaves of Code: evaluation and values, hashes and lists
Them What Make the Rules and Them What Live the Dream: case/when, while/until, variable scope, blocks, methods, class definitions, class attributes, objects, modules, introspection in IRB, dup, self, module
Downtown: metaprogramming, regular expressions
When You Wish Upon a Beard: send method, new methods in existing classes
The following chapters are "Expansion Packs":
The Tiger's Vest (with a Basic Introduction to IRB): discusses IRB, the interactive Ruby interpreter.
External links
Original Site
Actively maintained fork
3rd-party PDF version: Ruby Inside
Computer programming books
Creative Commons-licensed books
Ruby (programming language)
Books about free software |
https://en.wikipedia.org/wiki/Push%20Proxy%20Gateway | A Push Proxy Gateway is a component of WAP Gateways that pushes URL notifications to mobile handsets. Notifications typically include MMS, email, IM, ringtone downloads, and new device firmware notifications. Most notifications will have an audible alert to the user of the device. The notification will typically be a text string with a URL link. Note that only a notification is pushed to the device; the device must do something with the notification in order to download or view the content associated with it.
Technical specifications
PUSH to PPG
A push message is sent as an HTTP POST to the Push Proxy Gateway. The POST will be a multipart XML document, with the first part being the PAP (Push Access Protocol) Section and the second part being either a Service Indication or a Service Loading.
+---------------------------------------------+
| HTTP POST | \
+---------------------------------------------+ | WAP
| PAP XML | | PUSH
+---------------------------------------------+ | Flow
| Service Indication or Service Loading XML | /
+---------------------------------------------+
POST
The POST contains at a minimum the URL being posted to (this is not standard across different PPG vendors), and the content type.
An example of a PPG POST:
PAP
The PAP XML contains at the minimum, a <pap> element, a <push-message> element, and an <address> element.
An example of a PAP XML:
--someboundarymesg
Content-Type: application/xml
The important parts of this PAP message are the address value and type. The value is typically a MSISDN and type indicates whether to send to an MSISDN (typical case) or to an IP Address. The TYPE is almost always MSISDN as the Push Initiator (PI) will not typically have the Mobile Station's IP address - which is generally dynamic. In the case of IP Address:
TYPE=USER@a.b.c.d
Additional capability of PAP can be found in the PAP article.
Service In |
https://en.wikipedia.org/wiki/Partial%20order%20reduction | In computer science, partial order reduction is a technique for reducing the size of the state-space to be searched by a model checking or automated planning and scheduling algorithm. It exploits the commutativity of concurrently executed transitions that result in the same state when executed in different orders.
In explicit state space exploration, partial order reduction usually refers to the specific technique of expanding a representative subset of all enabled transitions. This technique has also been described as model checking with representatives. There are various versions of the method, the so-called stubborn set method, ample set method, and persistent set method.
Ample sets
Ample sets are an example of model checking with representatives. Their formulation relies on a separate notion of dependency. Two transitions are considered independent only if they cannot disable another whenever they are mutually enabled. The execution of both results in a unique state regardless of the order in which they are executed. Transitions that are not independent, are dependent. In practice dependency is approximated using static analysis.
Ample sets for different purposes can be defined by giving conditions as to when a set of transitions is "ample" in a given state.
C0
C1 If a transition depends on some transition relation in , this transition cannot be invoked until some transition in the ample set is executed.
Conditions C0 and C1 are sufficient for preserving all the deadlocks in the state space. Further restrictions are needed in order to preserve more nuanced properties. For instance, in order to preserve properties of linear temporal logic, the following two conditions are needed:
C2 If , each transition in the ample set is invisible.
C3 A cycle is not allowed if it contains a state in which some transition is enabled, but is never included in ample(s) for any states s on the cycle.
These conditions are sufficient for an ample set, but not necessary |
https://en.wikipedia.org/wiki/ARGUS%20distribution | In physics, the ARGUS distribution, named after the particle physics experiment ARGUS, is the probability distribution of the reconstructed invariant mass of a decayed particle candidate in continuum background.
Definition
The probability density function (pdf) of the ARGUS distribution is:
for . Here and are parameters of the distribution and
where and are the cumulative distribution and probability density functions of the standard normal distribution, respectively.
Cumulative distribution function
The cumulative distribution function (cdf) of the ARGUS distribution is
.
Parameter estimation
Parameter c is assumed to be known (the kinematic limit of the invariant mass distribution), whereas χ can be estimated from the sample X1, …, Xn using the maximum likelihood approach. The estimator is a function of sample second moment, and is given as a solution to the non-linear equation
.
The solution exists and is unique, provided that the right-hand side is greater than 0.4; the resulting estimator is consistent and asymptotically normal.
Generalized ARGUS distribution
Sometimes a more general form is used to describe a more peaking-like distribution:
where Γ(·) is the gamma function, and Γ(·,·) is the upper incomplete gamma function.
Here parameters c, χ, p represent the cutoff, curvature, and power respectively.
The mode is:
The mean is:
where M(·,·,·) is the Kummer's confluent hypergeometric function.
The variance is:
p = 0.5 gives a regular ARGUS, listed above. |
https://en.wikipedia.org/wiki/Orbital%20plane | The orbital plane of a revolving body is the geometric plane in which its orbit lies. Three non-collinear points in space suffice to determine an orbital plane. A common example would be the positions of the centers of a massive body (host) and of an orbiting celestial body at two different times/points of its orbit.
The orbital plane is defined in relation to a reference plane by two parameters: inclination (i) and longitude of the ascending node (Ω).
By definition, the reference plane for the Solar System is usually considered to be Earth's orbital plane, which defines the ecliptic, the circular path on the celestial sphere that the Sun appears to follow over the course of a year.
In other cases, for instance a moon or artificial satellite orbiting another planet, it is convenient to define the inclination of the Moon's orbit as the angle between its orbital plane and the planet's equatorial plane.
The coordinate system defined that uses the orbital plane as the plane is known as the perifocal coordinate system.
Artificial satellites around the Earth
For launch vehicles and artificial satellites, the orbital plane is a defining parameter of an orbit; as in general, it will take a very large amount of propellant to change the orbital plane of an object. Other parameters, such as the orbital period, the eccentricity of the orbit and the phase of the orbit are more easily changed by propulsion systems.
Orbital planes of satellites are perturbed by the non-spherical nature of the Earth's gravity. This causes the orbital plane of the satellite's orbit to slowly rotate around the Earth, depending on the angle the plane makes with the Earth's equator. For planes that are at a critical angle this can mean that the plane will track the Sun around the Earth, forming a Sun-synchronous orbit.
A launch vehicle's launch window is usually determined by the times when the target orbital plane intersects the launch site.
See also
Earth-centered inertial coordinate sys |
https://en.wikipedia.org/wiki/MOS%20Technology%208568 | The MOS Technology 8568 Video Display Controller (VDC) was the graphics processor responsible for the 80 column or RGBI display on the Commodore 128DCR personal computer. In the Commodore 128 service manual, this part was referred to as the "80 column CRT controller." The 8568 embodied many of the features of the older 6545E monochrome CRT controller plus RGBI color.
The original ("flat") Commodore 128 and the Commodore 128D (European plastic hausing) used the 8563 video controller to generate the 80 column display. The 8568 was essentially an updated version of the 8563, combining the latter's functionality with glue logic that had been implemented by discrete components in physical proximity to the 8563. Unlike the 8563, the 8568 included an unused (in the C-128) active low interrupt request line (/INTR), which was asserted when the "ready" bit in the 8568's status register changed from 0 to 1. Reading the control register would automatically deassert /INTR. Owing to differences in pin assignments and circuit interfacing, the 8563 and 8568 are not electrically interchangeable.
The Commodore 128 had two video display modes, which were usually used singularly, but could be used simultaneously if the computer was connected to two compatible video monitors. The VIC-II chip, also found in the Commodore 64, was mapped directly into main memory—the video memory and CPUs (the 8502 and Z80A processors) shared a common 128 KB RAM, and the VIC-II control registers were accessed as memory locations (that is, they were memory mapped).
Unlike the VIC-II, the 8568 had its own local video RAM, 64K in the C-128DCR model (sold in North America) and, depending on the date of manufacture of the particular machine, either 16 or 64K in the C-128D model (marketed in Europe). Addressing the VDC's internal registers and dedicated video memory must be accomplished by indirect means. First the program must tell the VDC which of its 37 internal registers is to be accessed. Next t |
https://en.wikipedia.org/wiki/Capacity%20planning | Capacity planning is the process of determining the production capacity needed by an organization to meet changing demands for its products. In the context of capacity planning, design capacity is the maximum amount of work that an organization or individual is capable of completing in a given period. Effective capacity is the maximum amount of work that an organization or individual is capable of completing in a given period due to constraints such as quality problems, delays, material handling, etc.
The phrase is also used in business computing and information technology as a synonym for capacity management. IT capacity planning involves estimating the storage, computer hardware, software and connection infrastructure resources required over some future period of time. A common concern of enterprises is whether the required resources are in place to handle an increase in users or number of interactions. Capacity management is concerned about adding central processing units (CPUs), memory and storage to a physical or virtual server. This has been the traditional and vertical way of scaling up web applications, however IT capacity planning has been developed with the goal of forecasting the requirements for this vertical scaling approach.
A discrepancy between the capacity of an organization and the demands of its customers results in inefficiency, either in under-utilized resources or unfulfilled customer demand. The goal of capacity planning is to minimize this discrepancy. Demand for an organization's capacity varies based on changes in production output, such as increasing or decreasing the production quantity of an existing product, or producing new products. Better utilization of existing capacity can be accomplished through improvements in overall equipment effectiveness (OEE). Capacity can be increased through introducing new techniques, equipment and materials, increasing the number of workers or machines, increasing the number of shifts, or acquiring a |
https://en.wikipedia.org/wiki/Anharmonicity | In classical mechanics, anharmonicity is the deviation of a system from being a harmonic oscillator. An oscillator that is not oscillating in harmonic motion is known as an anharmonic oscillator where the system can be approximated to a harmonic oscillator and the anharmonicity can be calculated using perturbation theory. If the anharmonicity is large, then other numerical techniques have to be used. In reality all oscillating systems are anharmonic, but most approximate the harmonic oscillator the smaller the amplitude of the oscillation is.
As a result, oscillations with frequencies and etc., where is the fundamental frequency of the oscillator, appear. Furthermore, the frequency deviates from the frequency of the harmonic oscillations. See also intermodulation and combination tones. As a first approximation, the frequency shift is proportional to the square of the oscillation amplitude :
In a system of oscillators with natural frequencies , , ... anharmonicity results in additional oscillations with frequencies .
Anharmonicity also modifies the energy profile of the resonance curve, leading to interesting phenomena such as the foldover effect and superharmonic resonance.
General principle
An oscillator is a physical system characterized by periodic motion, such as a pendulum, tuning fork, or vibrating diatomic molecule. Mathematically speaking, the essential feature of an oscillator is that for some coordinate of the system, a force whose magnitude depends on will push away from extreme values and back toward some central value , causing to oscillate between extremes. For example, may represent the displacement of a pendulum from its resting position . As the absolute value of increases, so does the restoring force acting on the pendulums weight that pushes it back towards its resting position.
In harmonic oscillators, the restoring force is proportional in magnitude (and opposite in direction) to the displacement of from its natural position |
https://en.wikipedia.org/wiki/Randstad%20NV | Randstad NV, commonly known as Randstad and stylized as randstad, is a Dutch multinational human resource consulting firm headquartered in Diemen, Netherlands. It was founded in the Netherlands in 1960 by Gerrit Daleboudt who asked Frits Goldschmeding to join him and operates in around 39 countries. Randstad NV is listed as RAND on the AEX of Euronext Amsterdam. Founder Frits Goldschmeding is still (April 2023) the biggest shareholder. The company is named after the Randstad region of the Netherlands.
Core activities
Randstad specializes in human resource services for temporary and permanent jobs, including contract staffing of professionals and senior managers.
In most of these countries, Randstad works according to a unit structure, whereby each unit consists of two consultants who are responsible for service provision to clients and selecting candidates. Randstad promotes these activities under two brand names: Randstad and Tempo Team.
A separate division of Randstad focuses on recruiting supervisors, managers, professionals, interim specialists, and advisors. These people are deployed in temporary positions in middle and senior management, such as engineers, ICT specialists, or marketing & communication specialists.
HR Solutions also involves a number of services such as selection processes, HR consultancy, outplacement, and career support.
Randstad operates under brands, including Randstad, Randstad Care, Tempo Team, Expectra, Ausy, and Yacht.
Randstad was a sponsor of the English Formula 1 team Williams F1 from 2006 until 2017. In 2019, Randstad became the sponsor of the Italian Formula 1 team Scuderia Toro Rosso, since 2020 called AlphaTauri.
History
1960–1970: The company's launch
Randstad was founded in 1960 by Frits Goldschmeding and Gerrit Daleboudt, who were both studying economics at the time at VU University Amsterdam. When Goldschmeding was supposed to write a thesis at the VU University Amsterdam his professor advised him to write a thesis on |
https://en.wikipedia.org/wiki/Instruction%20set%20simulator | An instruction set simulator (ISS) is a simulation model, usually coded in a high-level programming language, which mimics the behavior of a mainframe or microprocessor by "reading" instructions and maintaining internal variables which represent the processor's registers.
Instruction simulation is a methodology employed for one of several possible reasons:
To simulate the instruction set architecture (ISA) of a future processor to allow software development and test to proceed without waiting for the development and production of the hardware to finish. This is often known as "shift-left" or "pre-silicon support" in the hardware development field. A full system simulator or virtual platform for the future hardware typically includes one or more instruction set simulators.
To simulate the machine code of another hardware device or entire computer for upward compatibility.
For example, the IBM 1401 was simulated on the later IBM/360 through use of microcode emulation.
To monitor and execute the machine code instructions (but treated as an input stream) on the same hardware for test and debugging purposes, e.g. with memory protection (which protects against accidental or deliberate buffer overflow).
To improve the speed performance—compared to a slower cycle-accurate simulator—of simulations involving a processor core where the processor itself is not one of the elements being verified; in hardware description language design using Verilog where simulation with tools like ISS can be run faster by means of "PLI" (not to be confused with PL/1, which is a programming language).
Implementation
Instruction-set simulators can be implemented using three main techniques:
Interpretation, where each instruction is executed directly by the ISS.
Just-in-time compilation (JIT), where the code to be executed is first translated into the instruction set of the host computer. This is typically about ten times faster than a well-optimized interpreter.
Virtualization, wher |
https://en.wikipedia.org/wiki/Machine%20epsilon | Machine epsilon or machine precision is an upper bound on the relative approximation error due to rounding in floating point arithmetic. This value characterizes computer arithmetic in the field of numerical analysis, and by extension in the subject of computational science. The quantity is also called macheps and it has the symbols Greek epsilon .
There are two prevailing definitions. In numerical analysis, machine epsilon is dependent on the type of rounding used and is also called unit roundoff, which has the symbol bold Roman u. However, by a less formal, but more widely used definition, machine epsilon is independent of rounding method and may be equivalent to u or 2u.
Values for standard hardware arithmetics
The following table lists machine epsilon values for standard floating-point formats. Each format uses round-to-nearest.
Formal definition
Rounding is a procedure for choosing the representation of a real number in a floating point number system. For a number system and a rounding procedure, machine epsilon is the maximum relative error of the chosen rounding procedure.
Some background is needed to determine a value from this definition. A floating point number system is characterized by a radix which is also called the base, , and by the precision , i.e. the number of radix digits of the significand (including any leading implicit bit). All the numbers with the same exponent, , have the spacing, . The spacing changes at the numbers that are perfect powers of ; the spacing on the side of larger magnitude is times larger than the spacing on the side of smaller magnitude.
Since machine epsilon is a bound for relative error, it suffices to consider numbers with exponent . It also suffices to consider positive numbers. For the usual round-to-nearest kind of rounding, the absolute rounding error is at most half the spacing, or . This value is the biggest possible numerator for the relative error. The denominator in the relative error is the number be |
https://en.wikipedia.org/wiki/Diamond%E2%80%93Blackfan%20anemia | Diamond–Blackfan anemia (DBA) is a congenital erythroid aplasia that usually presents in infancy. DBA causes low red blood cell counts (anemia), without substantially affecting the other blood components (the platelets and the white blood cells), which are usually normal. This is in contrast to Shwachman–Bodian–Diamond syndrome, in which the bone marrow defect results primarily in neutropenia, and Fanconi anemia, where all cell lines are affected resulting in pancytopenia. There is a risk to develop acute myelogenous leukemia (AML) and certain other cancers.
A variety of other congenital abnormalities may also occur in DBA, such as hand anomalies.
Signs and symptoms
Diamond–Blackfan anemia is characterized by normocytic or macrocytic anemia (low red blood cell counts) with decreased erythroid progenitor cells in the bone marrow. This usually develops during the neonatal period. About 47% of affected individuals also have a variety of congenital abnormalities, including craniofacial malformations, thumb or upper limb abnormalities, cardiac defects, urogenital malformations, and cleft palate. Low birth weight and generalized growth delay are sometimes observed. DBA patients have a modest risk of developing leukemia and other malignancies.
Genetics
Most pedigrees suggest an autosomal dominant mode of inheritance with incomplete penetrance. Approximately 10–25% of DBA occurs with a family history of disease.
~70% of DBA cases can be attributed genetic mutations affecting ribosomal protein genes. The disease is characterized by genetic heterogeneity, affecting different ribosomal gene loci: Exceptions to this paradigm have been demonstrated, such as with rare mutations of transcription factor GATA1. RPS19, RPL5, RPS26, and RPL11 are the most frequently mutated genes in DBA patients. Given that ribosome function is essential for life, DBA patients carry loss-of-function alleles affecting only one copy. Initial descriptions of DBA patients primarily concentrated o |
https://en.wikipedia.org/wiki/Dyskeratosis%20congenita | Dyskeratosis congenita (DKC), also known as Zinsser-Engman-Cole syndrome, is a rare progressive congenital disorder with a highly variable phenotype. The entity was classically defined by the triad of abnormal skin pigmentation, nail dystrophy, and leukoplakia of the oral mucosa, and MDS/AML, but these components do not always occur. DKC is characterized by short telomeres. Some of the manifestations resemble premature ageing (similar to progeria) and cognitive impairment can be a feature. The disease initially mainly affects the skin, but a major consequence is progressive bone marrow failure which occurs in over 80%, causing early mortality.
Presentation
DKC can be characterized by cutaneous pigmentation, premature graying, dystrophy of the nails, leukoplakia of the oral mucosa, continuous lacrimation due to atresia of the lacrimal ducts, often thrombocytopenia, anemia, testicular atrophy in the male carriers, and predisposition to cancer. Many of these symptoms are characteristic of geriatrics, and those carrying the more serious forms of the disease often have significantly shortened lifespans. Also, liver abnormalities are associated with this syndrome, Nodular Regenerative Hypoplasia of the liver, although rare, it is one of many manifestations of liver disorders short telomeres can cause.
Predisposition to cancer
Susceptibility to cancer seems counterintuitive because in many known cancers reactivation of telomerase is actually a required step for malignancy to evolve (see telomere). In a disease where telomerase is affected, it does not seem to follow that cancer would be a complication to result. The authors note the paradoxical nature of cancer predisposition in individuals who seem to lack one of the required components for cancer to form. It is thought that without functional telomerase, chromosomes will likely be attached together at their ends through the non-homologous end joining pathway. If this proves to be a common enough occurrence, maligna |
https://en.wikipedia.org/wiki/Cartilage%E2%80%93hair%20hypoplasia | Cartilage–hair hypoplasia (CHH) is a rare genetic disorder. Symptoms may include short-limbed dwarfism due to skeletal dysplasia, variable level of immunodeficiency, and predisposition to cancer. It was first reported by Victor McKusick in 1965.
Signs and symptoms
Short limb dwarfism
Very fine, light hairs and eyebrows
Hyperextensible joints of hand and feet
Abnormalities of spine
Neutropenia
Defective antibody and cell mediated immunity
Genetics
CHH is an autosomal recessive inherited disorder. It is a highly pleiotropic disorder. A rarely encountered genetic phenomenon, known as uniparental disomy (a genetic circumstance where a child inherits two copies of a chromosome from one parent, as opposed to one copy from each parent) has also been observed with the disorder.
An association between mutations near or within the ncRNA component of RNase MRP, RMRP, has been identified. The endoribonuclease RNase MRP is a complex of RNA molecule and several proteins and it participates in cleavage of mitochondrial primers responsible for DNA replication and in pre-rRNA processing in the nucleolus. The locus of the gene has been mapped to the short arm of chromosome 9.
Immunodeficiency
Patients with CHH usually suffer from cellular immunodeficiency. In the study of 108 Finnish patients with CHH, there was detected mild to moderate form of lymphopenia, decreased delayed type of hypersensitivity and impaired responses to phytohemagglutinin. This leads to susceptibility to and, in some more severe cases, mortality from infections early in childhood. There has also been detected combined immunodeficiency in some patients.
Patients with CHH often have increased predispositions to malignancies.
Diagnosis
Treatment
A verified treatment for this disease is yet to be discovered.
See also
List of cutaneous conditions
List of radiographic findings associated with cutaneous conditions |
https://en.wikipedia.org/wiki/Microoxygenation | Micro-oxygenation is a process used in winemaking to introduce oxygen into wine in a controlled manner. Developed in 1991 by Patrick DuCournau, working with the exceptionally tannic grape Tannat in Madiran, the process gained usage in modern winemaking following the 1996 authorization by the European Commission. Today, the technique is widely employed in Bordeaux, as well as at least 11 different countries, including the United States and Chile.
Process
The process of micro-oxygenation involves a large two-chamber device with valves interconnected to a tank of oxygen. In the first chamber, the oxygen is calibrated to match the volume of the wine. In the second chamber, the oxygen is injected into the wine through a porous ceramic stone located at the bottom of the chamber. The dosage is controlled and can range anywhere from .75 to 3 cubic centimetres per liter of wine. The process normally occurs in multiple treatments that can last anywhere from one or two treatments during the early stages of fermentation (to help avoid stuck fermentation) to a more prolonged treatment during the maturation period that can last four to eight months.
Micro-oxygenation affects colour, aromatic bouquet, mouth-feel and phenolic content. Carboxypyranoanthocyanidins can be considered markers of microoxygenation techniques.
Benefits
Exposure to oxygen during production may improve wine, but the exposure must be limited: too much oxygen can lead to oxidation while too little can lead to reduction, either one leading to its associated wine faults. In barrel aging, the natural properties of the wood allow for gentle aeration of the wine to occur over a prolonged period. This aids in polymerization of tannin into larger molecules, which could fall out of solution, not promoting protein precipitation in the mouth and thus improving mouth astringency. The process of micro-oxygenation aims to mimic the effects of slow barrel maturation in a shorter period or for lower cost. It also enable |
https://en.wikipedia.org/wiki/White%20poppy | The white poppy is a flower used as a symbol of peace, worn either in place of or in addition to the red remembrance poppy for Remembrance Day or Anzac Day.
History
In 1926, a few years after the introduction of the red poppy in the UK, the idea of pacifists making their own poppies was put forward by a member of the No More War Movement (as well as the proposal that the black centre of the British Legion's red poppies should be imprinted with "No More War"). Their intention was to remember casualties of all wars, with the added meaning of a hope for the end of all wars; the red poppy signified only the British military dead. However, they did not pursue the idea. The first white poppies were sold by the Co-operative Women's Guild in 1933. The Peace Pledge Union (PPU) took part in their distribution from 1936, and white poppy wreaths were laid from 1937 as a pledge to peace that war must not happen again. Anti-war organisations such as the Anglican Pacifist Fellowship now support the White Poppy Movement.
Those who promote the wearing of white poppies argue that the red poppy also conveys a specific political standpoint, and point to the divisive nature of the red poppy in Northern Ireland, where it is worn mainly by unionists but boycotted by Irish republicans.
Sales of white poppies steadily rose throughout the 2010s, often causing supporters of the PPU to become targets of abuse. On 1 November 2018 sales of white poppies were higher than in any previous year since white poppies were founded in 1933. As of 7 November 2018, 119,555 white poppies had been sold. The final figure was 122,385. The previous record was 110,000 white poppies in 2015. Until 2014, the record was around 80,000 in 1938.
Those who endorse the white poppy campaign include actor Mark Rylance, poet Benjamin Zephaniah and rapper Lowkey.
Children's author Michael Morpurgo described his decision to wear a white poppy alongside his red one in a Radio Times article:
"Wearing the red poppy for me |
https://en.wikipedia.org/wiki/Metal%20Slug%203 | is a run and gun video game developed by SNK. It was originally released in 2000 for the Neo-Geo MVS arcade platform as the sequel to Metal Slug 2/Metal Slug X. The music of the game was developed by Noise Factory.
The game was ported to the PlayStation 2, Xbox, Microsoft Windows, iOS, Android, Wii, PlayStation Portable, PlayStation 3, PlayStation 4, PlayStation Vita, and Nintendo Switch.
The game adds several features to the gameplay of the original Metal Slug and Metal Slug 2, such as weapons and vehicles, as well as introducing branching paths into the series. It received generally positive reviews.
Gameplay
The gameplay mechanics are the same as in previous Metal Slug games; the player must shoot constantly at a continual stream of enemies in order to reach the end of each level. At this point, the player confronts a boss, who is usually considerably larger and tougher than regular enemies. On the way through each level, the player can find numerous weapon upgrades and "Metal Slug" tanks. The tank is known as the SV-001 ("SV" stands for Super Vehicle), which increases the player's offense and considerably adds to their defense.
In addition to shooting, the player can perform melee attacks by using a knife and/or kicking. The player does not die by coming into contact with enemies, and correspondingly, many of the enemy troops have melee attacks. Much of the game's scenery is destructible, and occasionally, this reveals extra items or power-ups.
During the course of a level, the player encounters prisoners of war (POWs), who, if freed, offer the player bonuses in the form of random items or weapons. At the end of each level, the player receives a scoring bonus based on the number of freed POWs. If the player dies before the end of the level, the tally of freed POWs reverts to zero.
A new feature in Metal Slug 3 is the branching path system; in most missions, there are forking paths from which the player must choose one, each with their own obstacles, and |
https://en.wikipedia.org/wiki/Interdimensional | Interdimensional may refer to:
Interdimensional hypothesis
Interdimensional doorway
Interdimensional travel
Dimension |
https://en.wikipedia.org/wiki/Fenchel%27s%20theorem | In differential geometry, Fenchel's theorem is an inequality on the total absolute curvature of a closed smooth space curve, stating that it is always at least . Equivalently, the average curvature is at least , where is the length of the curve. The only curves of this type whose total absolute curvature equals and whose average curvature equals are the plane convex curves. The theorem is named after Werner Fenchel, who published it in 1929.
The Fenchel theorem is enhanced by the Fáry–Milnor theorem, which says that if a closed smooth simple space curve is nontrivially knotted, then the total absolute curvature is greater than .
Proof
Given a closed smooth curve with unit speed, the velocity is also a closed smooth curve. The total absolute curvature is its length .
The curve does not lie in an open hemisphere. If so, then there is such that , so , a contradiction. This also shows that if lies in a closed hemisphere, then , so is a plane curve.
Consider a point such that curves and have the same length. By rotating the sphere, we may assume and are symmetric about the axis through the poles. By the previous paragraph, at least one of the two curves and intersects with the equator at some point . We denote this curve by . Then .
We reflect across the plane through , , and the north pole, forming a closed curve containing antipodal points , with length . A curve connecting has length at least , which is the length of the great semicircle between . So , and if equality holds then does not cross the equator.
Therefore, , and if equality holds then lies in a closed hemisphere, and thus is a plane curve. |
https://en.wikipedia.org/wiki/Fenchel%27s%20duality%20theorem | In mathematics, Fenchel's duality theorem is a result in the theory of convex functions named after Werner Fenchel.
Let ƒ be a proper convex function on Rn and let g be a proper concave function on Rn. Then, if regularity conditions are satisfied,
where ƒ * is the convex conjugate of ƒ (also referred to as the Fenchel–Legendre transform) and g * is the concave conjugate of g. That is,
Mathematical theorem
Let X and Y be Banach spaces, and be convex functions and be a bounded linear map. Then the Fenchel problems:
satisfy weak duality, i.e. . Note that are the convex conjugates of f,g respectively, and is the adjoint operator. The perturbation function for this dual problem is given by .
Suppose that f,g, and A satisfy either
f and g are lower semi-continuous and where is the algebraic interior and , where h is some function, is the set , or
where are the points where the function is continuous.
Then strong duality holds, i.e. . If then supremum is attained.
One-dimensional illustration
In the following figure, the minimization problem on the left side of the equation is illustrated. One seeks to vary x such that the vertical distance between the convex and concave curves at x is as small as possible. The position of the vertical line in the figure is the (approximate) optimum.
The next figure illustrates the maximization problem on the right hand side of the above equation. Tangents are drawn to each of the two curves such that both tangents have the same slope p. The problem is to adjust p in such a way that the two tangents are as far away from each other as possible (more precisely, such that the points where they intersect the y-axis are as far from each other as possible). Imagine the two tangents as metal bars with vertical springs between them that push them apart and against the two parabolas that are fixed in place.
Fenchel's theorem states that the two problems have the same solution. The points having the minimum vertical sepa |
https://en.wikipedia.org/wiki/Fluorodeoxyglucose%20%2818F%29 | {{DISPLAYTITLE:Fluorodeoxyglucose (18F)}}
[18F]Fluorodeoxyglucose (INN), or fluorodeoxyglucose F 18 (USAN and USP), also commonly called fluorodeoxyglucose and abbreviated [18F]FDG, 2-[18F]FDG or FDG, is a radiopharmaceutical, specifically a radiotracer, used in the medical imaging modality positron emission tomography (PET). Chemically, it is 2-deoxy-2-[18F]fluoro-D-glucose, a glucose analog, with the positron-emitting radionuclide fluorine-18 substituted for the normal hydroxyl group at the C-2 position in the glucose molecule.
The uptake of [18F]FDG by tissues is a marker for the tissue uptake of glucose, which in turn is closely correlated with certain types of tissue metabolism. After [18F]FDG is injected into a patient, a PET scanner can form two-dimensional or three-dimensional images of the distribution of [18F]FDG within the body.
Since its development in 1976, [18F]FDG had a profound influence on research in the neurosciences. The subsequent discovery in 1980 that [18F]FDG accumulates in tumors underpins the evolution of PET as a major clinical tool in cancer diagnosis. [18F]FDG is now the standard radiotracer used for PET neuroimaging and cancer patient management.
The images can be assessed by a nuclear medicine physician or radiologist to provide diagnoses of various medical conditions.
History
In 1968, Dr. Josef Pacák, Zdeněk Točík and Miloslav Černý at the Department of Organic Chemistry, Charles University, Czechoslovakia were the first to describe the synthesis of FDG. Later, in the 1970s, Tatsuo Ido and Al Wolf at the Brookhaven National Laboratory were the first to describe the synthesis of FDG labeled with fluorine-18. The compound was first administered to two normal human volunteers by Abass Alavi in August, 1976 at the University of Pennsylvania. Brain images obtained with an ordinary (non-PET) nuclear scanner demonstrated the concentration of [18F]FDG in that organ (see history reference below).
Beginning in August 1990, and continuing |
https://en.wikipedia.org/wiki/Kiss%20%28cryptanalysis%29 | In cryptanalysis, a kiss is a pair of identical messages sent using different ciphers, one of which has been broken. The term was used at Bletchley Park during World War II. A deciphered message in the breakable system provided a "crib" (piece of known plaintext) which could then be used to read the unbroken messages. One example was where messages read in a German meteorological cipher could be used to provide cribs for reading the difficult 4-wheel Naval Enigma cipher.
cribs from re-encipherments ... were known as 'kisses' in Bletchley Park parlance because the relevant signals were marked with 'xx'
See also
Cryptanalysis of the Enigma
Known-plaintext attack |
https://en.wikipedia.org/wiki/Radio%20teleswitch | A radio teleswitch is a device used in the United Kingdom primarily to allow electricity suppliers to switch large numbers of electricity meters between different tariff rates, by broadcasting an embedded signal in broadcast radio signals. Radio teleswitches are also used to switch on/off consumer appliances to make use of cheaper differential tariffs such as Economy 7.
Service role
The typical use of a teleswitch is to manage the start and end times of off-peak charging periods associated with tariffs such as Economy 7 and Economy 10. This includes switching between 'peak' and 'off-peak' meter registers as well as controlling the supply to dedicated off-peak loads such as night storage heating. The use of dynamic switching instead of a fixed timer allows some additional demand management, such as by flexing start and finish times for electric heating loads according to prevailing overall demand levels.
Some suppliers also offer more sophisticated heating control using the radio teleswitch network. For example, Scottish Power 'Weathercall' and SSE's 'Total Heat Total Control' both dynamically vary the length of time storage heating is energised each night depending on the forecast temperature for the following day to help maintain a consistent household temperature.
Teleswitching has also been used to help level out demand in areas where the supply network is close to capacity. In the 1990s, Manweb used such a system to provide different households with different off-peak periods on a weekly alternating basis. By spreading out the high peak demand associated with electric storage heating in Mid Wales, the company avoided upgrading costs of over a million pounds, and £200,000 a year in reduced use-of-system charges.
In the north of Scotland, the radio teleswitch service is also used to help control the local electricity distribution network for resilience purposes.
Operation
Each of the user companies (the RTS Users, or Service Providers) has its own database |
Subsets and Splits
No community queries yet
The top public SQL queries from the community will appear here once available.