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Transmitted light microscope Condenser Transmitted_light_microscope > Components > Condenser The condenser is a lens designed to focus light from the illumination source onto the sample. The condenser may also include other features, such as a diaphragm and/or filters, to manage the quality and intensity of the illumination. For illumination techniques like dark field, phase contrast and differential interference contrast microscopy additional optical components must be precisely aligned in the light path.
PID algorithm Loop tuning Steady-state_error > Loop tuning Designing and tuning a PID controller appears to be conceptually intuitive, but can be hard in practice, if multiple (and often conflicting) objectives, such as short transient and high stability, are to be achieved. PID controllers often provide acceptable control using default tunings, but performance can generally be improved by careful tuning, and performance may be unacceptable with poor tuning. Usually, initial designs need to be adjusted repeatedly through computer simulations until the closed-loop system performs or compromises as desired. Some processes have a degree of nonlinearity, so parameters that work well at full-load conditions do not work when the process is starting up from no load. This can be corrected by gain scheduling (using different parameters in different operating regions).
Non-muscle invasive bladder cancer Infection Non-muscle_invasive_bladder_cancer > Causes > Infection They cause alkylation DNA damage, specially Guanine to Adenine transition mutations in the HRAS and p53 tumor suppressor gene. Mutations of p53 are detected in 73% of the tumors, BCL-2 mutations accounting for 32% and the combination of the two accounting for 13%. Other causes of squamous cell carcinoma of the bladder include chronic catheterizations in people with a spinal cord injury and history of treatment with cyclophosphamide.
History of tuberculosis Containment History_of_tuberculosis > Twentieth century > Containment At the beginning of the 20th century, tuberculosis was one of the UK's most urgent health problems. A royal commission was set up in 1901, The Royal Commission Appointed to Inquire into the Relations of Human and Animal Tuberculosis. Its remit was to find out whether tuberculosis in animals and humans was the same disease, and whether animals and humans could infect each other. By 1919, the Commission had evolved into the UK's Medical Research Council.
Protein Protein purification Protein_function > Methods of study > Protein purification To simplify this process, genetic engineering is often used to add chemical features to proteins that make them easier to purify without affecting their structure or activity. Here, a "tag" consisting of a specific amino acid sequence, often a series of histidine residues (a "His-tag"), is attached to one terminus of the protein. As a result, when the lysate is passed over a chromatography column containing nickel, the histidine residues ligate the nickel and attach to the column while the untagged components of the lysate pass unimpeded. A number of different tags have been developed to help researchers purify specific proteins from complex mixtures.
Black body spectrum Further explanation Black-body_radiation > Theory > Further explanation According to the Classical Theory of Radiation, if each Fourier mode of the equilibrium radiation (in an otherwise empty cavity with perfectly reflective walls) is considered as a degree of freedom capable of exchanging energy, then, according to the equipartition theorem of classical physics, there would be an equal amount of energy in each mode. Since there are an infinite number of modes, this would imply infinite heat capacity, as well as a nonphysical spectrum of emitted radiation that grows without bound with increasing frequency, a problem known as the ultraviolet catastrophe. In the longer wavelengths this deviation is not so noticeable, as h ν {\displaystyle h\nu } and n h ν {\displaystyle nh\nu } are very small. In the shorter wavelengths of the ultraviolet range, however, classical theory predicts the energy emitted tends to infinity, hence the ultraviolet catastrophe.
Nervous system network models Computational neuron models Nervous_system_network_models > Nervous system models > Computational neuron models Computational neuroscience is an interdisciplinary field that combines engineering, biology, control systems, brain functions, physical sciences, and computer science. It has fundamental development models done at the lower levels of ions, neurons, and synapses, as well as information propagation between neurons. These models have established the enabling technology for higher-level models to be developed. They are based on chemical and electrical activities in the neurons for which electrical equivalent circuits are generated.
Log-linear analysis Assumptions Log-linear_analysis > Assumptions There are three assumptions in log-linear analysis:1. The observations are independent and random; 2. Observed frequencies are normally distributed about expected frequencies over repeated samples. This is a good approximation if both (a) the expected frequencies are greater than or equal to 5 for 80% or more of the categories and (b) all expected frequencies are greater than 1.
Driver CPC What is Driver CPC? Driver_CPC > What is Driver CPC? This must be maintained with 35 hours of periodic training every 5 years or the certificate will lapse. Bus and coach (PCV) drivers who hold a relevant vocational licence (D, D1, D+E and D1+E) gained before 10 September 2008, (including restricted vocational licence D(101) issued after 1991 and D1(101) issued before 1997) and lorry (LGV) drivers who obtained their licence (C, C1, C+E and C1+E) before 10 September 2009, do not need to take the initial qualification as they are deemed to hold 'acquired rights'. They must still complete periodic training to maintain their Driver CPC.
Operational calculus History Operational_calculus > History Guided greatly by intuition and his wealth of knowledge on the physics behind his circuit studies, developed the operational calculus now ascribed to his name.At the time, Heaviside's methods were not rigorous, and his work was not further developed by mathematicians. Operational calculus first found applications in electrical engineering problems, for the calculation of transients in linear circuits after 1910, under the impulse of Ernst Julius Berg, John Renshaw Carson and Vannevar Bush. A rigorous mathematical justification of Heaviside's operational methods came only after the work of Bromwich that related operational calculus with Laplace transformation methods (see the books by Jeffreys, by Carslaw or by MacLachlan for a detailed exposition).
Instruction pointer Summary Instruction_pointer The program counter (PC), commonly called the instruction pointer (IP) in Intel x86 and Itanium microprocessors, and sometimes called the instruction address register (IAR), the instruction counter, or just part of the instruction sequencer, is a processor register that indicates where a computer is in its program sequence.Usually, the PC is incremented after fetching an instruction, and holds the memory address of ("points to") the next instruction that would be executed.Processors usually fetch instructions sequentially from memory, but control transfer instructions change the sequence by placing a new value in the PC. These include branches (sometimes called jumps), subroutine calls, and returns. A transfer that is conditional on the truth of some assertion lets the computer follow a different sequence under different conditions.
Decentralized information technology Organizational structure of a firm Decentralization > Economic decentralization > Organizational structure of a firm These benefits are enhanced in firms with skill-intensive environments. Skilled workers are more able to analyze information, they pose less risk of information duplication given increased communication abilities, and the productivity cost of multi-tasking is lower. These outcomes of decentralizion make it a particularly effective organizational structure for entrepreneurial and competitive firm environments, such as start-up companies. The flexibility, efficiency of information flow and higher worker autonomy complement the rapid growth and innovation seen in successful start up companies.
Radiation biology Summary Radiobiology Radiobiology (also known as radiation biology, and uncommonly as actinobiology) is a field of clinical and basic medical sciences that involves the study of the effects of ionizing radiation on living things, in particular health effects of radiation. Ionizing radiation is generally harmful and potentially lethal to living things but can have health benefits in radiation therapy for the treatment of cancer and thyrotoxicosis. Its most common impact is the induction of cancer with a latent period of years or decades after exposure. High doses can cause visually dramatic radiation burns, and/or rapid fatality through acute radiation syndrome. Controlled doses are used for medical imaging and radiotherapy.
Mental model Summary Mental_model A mental model in psychology is an internal representation of external reality, hypothesized to play a major role in cognition, reasoning and decision-making. The term was coined by Kenneth Craik in 1943 who suggested that the mind constructs "small-scale models" of reality that it uses to anticipate events. Mental models can help shape behaviour and set an approach to solving problems (similar to a personal algorithm) and doing tasks. In psychology, the term mental models is sometimes used to refer to mental representations or mental simulation generally.
Pyridine ring Nucleophilic substitutions Pyridine > Reactions > Nucleophilic substitutions So fluorine is the best leaving group for the substitution with organolithium compounds. The nucleophilic attack compounds may be alkoxides, thiolates, amines, and ammonia (at elevated pressures).In general, the hydride ion is a poor leaving group and occurs only in a few heterocyclic reactions. They include the Chichibabin reaction, which yields pyridine derivatives aminated at the 2-position.
Special Relativity Summary Theoretical_total_mass-energy In physics, the special theory of relativity, or special relativity for short, is a scientific theory of the relationship between space and time. In Albert Einstein's 1905 treatment, the theory is presented as being based on just two postulates: The laws of physics are invariant (identical) in all inertial frames of reference (that is, frames of reference with no acceleration). The speed of light in vacuum is the same for all observers, regardless of the motion of light source or observer.
Chylomicron retention disease Signs and symptoms Chylomicron_retention_disease > Signs and symptoms Without Vitamin E, neurons cannot operate correctly and signals from the brain are weakened. This leads to reduced muscle development and reduced muscle contraction. Symptoms that manifest in the GI tract are likely to be a consequence of both reduced absorption of fats and physiological stress imposed on enterocytes that can not shuttle fats into circulation .
Machine learning Statistics Machine_learning > History and relationships to other fields > Statistics In contrast, machine learning is not built on a pre-structured model; rather, the data shape the model by detecting underlying patterns. The more variables (input) used to train the model, the more accurate the ultimate model will be.Leo Breiman distinguished two statistical modeling paradigms: data model and algorithmic model, wherein "algorithmic model" means more or less the machine learning algorithms like Random Forest. Some statisticians have adopted methods from machine learning, leading to a combined field that they call statistical learning.
Eccentric training Eccentric exercise Eccentric_exercise > Eccentric exercise Negative work is the mechanical energy absorbed by the work conducted on a muscle when the force on the muscle is greater than the force produced. An experiment was conducted on bicycle riding. The amount of oxygen consumption was measured during the motion of pedaling forward as positive work and pedaling with resistance as negative work.
Discovery and development of beta-blockers Synthesis Discovery_and_development_of_beta-blockers > Synthesis The second way is shown as the lower route in figure 5. It consists of displacement of the halogen directly with a SN2 reaction to give the same glycidic ether.
Thermal Energy Storage Molecular bonds Thermal_storage > Categories > Thermo-chemical heat storage > Molecular bonds This sounds easier than it actually is. Four electrons of the water molecules need to be separated and transported elsewhere.
Michell structures Summary Michell_structures Michell structures are structures that are optimal based on the criteria defined by A.G.M. Michell in his frequently referenced 1904 paper.Michell states that “a frame (today called truss) (is optimal) attains the limit of economy of material possible in any frame-structure under the same applied forces, if the space occupied by it can be subjected to an appropriate small deformation, such that the strains in all the bars of the frame are increased by equal fractions of their lengths, not less than the fractional change of length of any element of the space.” The above conclusion is based on the Maxwell load-path theorem: ∑ l p f p − ∑ l q f q = C {\displaystyle \sum _{}l_{p}f_{p}-\sum _{}l_{q}f_{q}=C} Where f p {\displaystyle f_{p}} is the tension value in any tension element of length l p {\displaystyle l_{p}} , f q {\displaystyle f_{q}} is the compression value in any compression element of length l q {\displaystyle l_{q}} and C {\displaystyle C} is a constant value which is based on external loads applied to the structure. Based on the Maxwell load-path theorem, reducing load path of tension members ∑ l p f p {\displaystyle \textstyle \sum _{}l_{p}f_{p}} will reduce by the same value the load path of compression elements ∑ l q f q {\displaystyle \textstyle \sum _{}l_{q}f_{q}} for a given set of external loads. Structure with minimum load path is one having minimum compliance (having minimum weighted deflection in the points of applied loads weighted by the values of these loads). In consequence Michell structures are minimum compliance trusses.
Primality tests Other tests Primality_tests > Probabilistic tests > Other tests Leonard Adleman and Ming-Deh Huang presented an errorless (but expected polynomial-time) variant of the elliptic curve primality test. Unlike the other probabilistic tests, this algorithm produces a primality certificate, and thus can be used to prove that a number is prime. The algorithm is prohibitively slow in practice. If quantum computers were available, primality could be tested asymptotically faster than by using classical computers. A combination of Shor's algorithm, an integer factorization method, with the Pocklington primality test could solve the problem in O ( ( log ⁡ n ) 3 ( log ⁡ log ⁡ n ) 2 log ⁡ log ⁡ log ⁡ n ) {\displaystyle O((\log n)^{3}(\log \log n)^{2}\log \log \log n)} .
Statistical bias Data selection Detection_bias > Types > Data selection Observer selection bias occurs when the evidence presented has been pre-filtered by observers, which is so-called anthropic principle. The data collected is not only filtered by the design of experiment, but also by the necessary precondition that there must be someone doing a study. An example is the impact of the Earth in the past.
Shared memory In hardware Shared_memory_architecture > In hardware Shared memory computers cannot scale very well. Most of them have ten or fewer processors; lack of data coherence: whenever one cache is updated with information that may be used by other processors, the change needs to be reflected to the other processors, otherwise the different processors will be working with incoherent data. Such cache coherence protocols can, when they work well, provide extremely high-performance access to shared information between multiple processors.
Basal ganglia Pallidum Basal_nuclei > Structure > Pallidum The GPe receives input mainly from the striatum, and projects to the subthalamic nucleus. The GPi receives signals from the striatum via the "direct" and "indirect" pathways. Pallidal neurons operate using a disinhibition principle. These neurons fire at steady high rates in the absence of input, and signals from the striatum cause them to pause or reduce their rate of firing. Because pallidal neurons themselves have inhibitory effects on their targets, the net effect of striatal input to the pallidum is a reduction of the tonic inhibition exerted by pallidal cells on their targets (disinhibition) with an increased rate of firing in the targets.
Serotonin toxicity Pathophysiology Serotonin_toxicity > Pathophysiology Serotonin is a neurotransmitter involved in multiple complex biological processes including aggression, pain, sleep, appetite, anxiety, depression, migraine, and vomiting. In humans the effects of excess serotonin were first noted in 1960 in patients receiving an MAOI and tryptophan. The syndrome is caused by increased serotonin in the CNS. It was originally suspected that agonism of 5-HT1A receptors in central grey nuclei and the medulla was responsible for the development of the syndrome.
Failure modes of electronics Contact failures Failure_modes_of_electronics > Contact failures Corrosion may cause buildup of oxides and other nonconductive products on the contact surfaces. When closed, these then show unacceptably high resistance; they may also migrate and cause shorts. Tin whiskers can form on tin-coated metals like the internal side of the packagings; loose whiskers then can cause intermittent short circuits inside the packaging. Cables, in addition to the methods described above, may fail by fraying and fire damage.
Cap and Share Design Cap_and_Share > Design 'Classic' Cap and Share says people in rich countries should not be entitled to greater allocations than those in poor countries - all allocations should be equal - but it also suggests that in the early years of the system, a portion of everyone's emissions entitlement should be held back and distributed to governments of countries which were facing exceptional difficulties in adapting to climate change or to low levels of fossil energy use. The governments involved would sell their certificates to raise money for remedial works. For example, the government of Bangladesh might sell its allocation to pay for better defenses against rising sea levels.
Table of Integrals, Series, and Products Japanese edition Table_of_Integrals,_Series,_and_Products > Editions > Japanese edition Градштейн (Guradoshu グラドシュ), И. С.; Рыжик (Rijiku リジク), И. М. (December 1983). Sūgaku daikōshikishū 数学大公式集 (in Japanese). Translated by Otsuki, Yoshihiko (大槻義彦) (1 ed.).
Earth ship Power Earthship > Power Earthships are designed to collect and store their own energy. The majority of electrical energy is harvested from the sun and wind. Photovoltaic panels and wind turbines on or near the Earthship generate DC electricity that is stored in deep-cycle batteries. The batteries are housed in a purpose-built room on the roof.
Seasonal breeder Physiology Seasonal_breeder > Physiology The hypothalamus is considered to be the central control for reproduction due to its role in hormone regulation. Hence, factors that determine when a seasonal breeder will be ready for mating affect this tissue. This is achieved specifically through changes in the production of the hormone GnRH. GnRH in turn transits to the pituitary where it promotes the secretion of the gonadotropins LH and FSH, both pituitary hormones critical for reproductive function and behavior, into the bloodstream. Changes in gonadotropin secretion initiate the end of anestrus in females.
Language codes Summary Language_codes A language code is a code that assigns letters or numbers as identifiers or classifiers for languages. These codes may be used to organize library collections or presentations of data, to choose the correct localizations and translations in computing, and as a shorthand designation for longer forms of language names.
Frantz Yvelin Early life and education Frantz_Yvelin > Early life and education A commercial pilot since the age of 21, Yvelin is type-rated on Airbus A320, Boeing 737, Boeing 757, Boeing 767, Cessna Citation and McDonnell Douglas MD80.
Twin Earth thought experiment The thought experiment Twin_Earth_thought_experiment > The thought experiment Putnam's original formulation of the experiment was this: We begin by supposing that elsewhere in the universe there is a planet exactly like Earth in virtually all aspects, which we refer to as "Twin Earth". (We should also suppose that the relevant surroundings are exactly the same as for Earth; it revolves around a star that appears to be exactly like our sun, and so on). On Twin Earth, there is a Twin equivalent of every person and thing here on Earth.
Cancer immunotherapy Immune checkpoints PD-1_inhibitor > Research > Immune checkpoints Immune checkpoints affect the immune system function. Immune checkpoints can be stimulatory or inhibitory. Tumors can use these checkpoints to protect themselves from immune system attacks. Currently approved checkpoint therapies block inhibitory checkpoint receptors.
Quantity equation Percentages, derivatives and integrals Quantity_equation > Concrete numbers and base units > Percentages, derivatives and integrals Percentages are dimensionless quantities, since they are ratios of two quantities with the same dimensions. In other words, the % sign can be read as "hundredths", since 1% = 1/100. Taking a derivative with respect to a quantity divides the dimension by the dimension of the variable that is differentiated with respect to.
Economic equilibrium Example: Nash equilibrium Market_equilibrium > Properties of equilibrium > Example: Nash equilibrium In the standard Cournot model this is downward sloping: if the other firm produces a higher output, the best response involves producing less. Best response dynamics involves firms starting from some arbitrary position and then adjusting output to their best-response to the previous output of the other firm. So long as the reaction functions have a slope of less than -1, this will converge to the Nash equilibrium.
Open pond Photobioreactors Open_pond > Growing, harvesting, and processing algae > Methods > Photobioreactors A PBR can operate in "batch mode", which involves restocking the reactor after each harvest, but it is also possible to grow and harvest continuously. Continuous operation requires precise control of all elements to prevent immediate collapse.
Quantum system Particle in a box Quantum_laws > Examples > Particle in a box With the differential operator defined by p ^ x = − i ℏ d d x {\displaystyle {\hat {p}}_{x}=-i\hbar {\frac {d}{dx}}} the previous equation is evocative of the classic kinetic energy analogue, 1 2 m p ^ x 2 = E , {\displaystyle {\frac {1}{2m}}{\hat {p}}_{x}^{2}=E,} with state ψ {\displaystyle \psi } in this case having energy E {\displaystyle E} coincident with the kinetic energy of the particle. The general solutions of the Schrödinger equation for the particle in a box are ψ ( x ) = A e i k x + B e − i k x E = ℏ 2 k 2 2 m {\displaystyle \psi (x)=Ae^{ikx}+Be^{-ikx}\qquad \qquad E={\frac {\hbar ^{2}k^{2}}{2m}}} or, from Euler's formula, ψ ( x ) = C sin ⁡ ( k x ) + D cos ⁡ ( k x ) . {\displaystyle \psi (x)=C\sin(kx)+D\cos(kx).\!}
Power harassment Summary Power_harassment Power harassment is a form of harassment and workplace bullying in which someone in a position of greater power uses that power to harass or bully a lower-ranking person. It includes a range of behavior from mild irritation and annoyances to serious abuses which can even involve forced activity beyond the boundaries of the job description. Prohibited in some countries, power harassment is considered a form of illegal discrimination and political and psychological abuse. Types of power harassment include physical or psychological attacks, segregation, excessive or demeaning work assignments, and intrusion upon the victim's personal life.Power harassment may combine with other forms of bias and harassment, including sexual harassment.
Arc system Mechanism Arc_system > Mechanism Phosphorylated ArcA is then able to attach to specific, consensus gene sequences on the chromosome regulating approximately 30 different operons. ArcA is able to acts as both a repressor and an activator depending on which operon it attaches.When oxygen levels are low, ArcB acts as a phosphatase, removing the inorganic phosphate group from ArcA. Without the attached phosphate group, ArcA is unable to bind to DNA and genes return to their original, aerobic levels of expression.
Circuit theory Small signal equivalent circuit Non-linear_networks > Non-linear networks > Methods > Small signal equivalent circuit This method can be used where the deviation of the input and output signals in a network stay within a substantially linear portion of the non-linear devices transfer function, or else are so small that the curve of the transfer function can be considered linear. Under a set of these specific conditions, the non-linear device can be represented by an equivalent linear network. It must be remembered that this equivalent circuit is entirely notional and only valid for the small signal deviations. It is entirely inapplicable to the dc biasing of the device.
Chemical fuel Chemical Chemical_fuel > Chemical Chemical fuels are substances that release energy by reacting with substances around them, most notably by the process of combustion. Chemical fuels are divided in two ways. First, by their physical properties, as a solid, liquid or gas. Secondly, on the basis of their occurrence: primary (natural fuel) and secondary (artificial fuel). Thus, a general classification of chemical fuels is:
Thermal profiling Thermocouple attachments Thermal_profiling > Soldering of electronic products > Thermocouple attachments Aluminum tape comes in various thicknesses and density. Heavier aluminum tape can defuse the heat transfer through the tape and act as an insulator. Low density aluminum tape allows for heat transfer to the EMF-producing area of the TC. The thermal conductivity of the aluminum tape allows for even conduction when the thickness of the tape is fairly consistent in the EMF-producing area of the thermocouple.
Biological network DNA-DNA chromatin networks Biological_network > Networks in biology > DNA-DNA chromatin networks Within a nucleus, DNA is constantly in motion. Perpetual actions such as genome folding and Cohesin extrusion morph the shape of a genome in real time. The spatial location of strands of chromatin relative to each other plays an important role in the activation or suppression of certain genes. DNA-DNA Chromatin Networks help biologists to understand these interactions by analyzing commonalities amongst different loci.
MAXEkSAT Summary MAXEkSAT MAXEkSAT is a problem in computational complexity theory that is a maximization version of the Boolean satisfiability problem 3SAT. In MAXEkSAT, each clause has exactly k literals, each with distinct variables, and is in conjunctive normal form. These are called k-CNF formulas.
NewSQL Summary NewSQL NewSQL is a class of relational database management systems that seek to provide the scalability of NoSQL systems for online transaction processing (OLTP) workloads while maintaining the ACID guarantees of a traditional database system.Many enterprise systems that handle high-profile data (e.g., financial and order processing systems) are too large for conventional relational databases, but have transactional and consistency requirements that are not practical for NoSQL systems. The only options previously available for these organizations were to either purchase more powerful computers or to develop custom middleware that distributes requests over conventional DBMS. Both approaches feature high infrastructure costs and/or development costs. NewSQL systems attempt to reconcile the conflicts.
Complexification Formal definition Complexification > Formal definition As it stands, V C {\displaystyle V^{\mathbb {C} }} is only a real vector space. However, we can make V C {\displaystyle V^{\mathbb {C} }} into a complex vector space by defining complex multiplication as follows: α ( v ⊗ β ) = v ⊗ ( α β ) for all v ∈ V and α , β ∈ C .
Scandium acetate Summary Scandium_acetate Scandium acetate is an inorganic compound, with the chemical formula of Sc(CH3COO)3. It exists in the anhydrous and the hydrate forms. It can be obtained by reacting scandium hydroxide with aqueous acetic acid.
Diffuse proliferative nephritis End Stage Renal Disease Diffuse_proliferative_nephritis > Epidemiology > End Stage Renal Disease About 38% of people with ESRD will be diagnosed with DPGN. In the United States, about 4.5 per million cases of ESRD are caused by DPGN.
Open rate Summary Open_rate There are two types of "open rates" one for electronic mail (aka e-mail; see below) and one for physical mail (aka snail mail via the USPS or other physical mail carrier).
Membrane potential Summary Cell_excitability This is called a depolarization if the interior voltage becomes less negative (say from –70 mV to –60 mV), or a hyperpolarization if the interior voltage becomes more negative (say from –70 mV to –80 mV). In excitable cells, a sufficiently large depolarization can evoke an action potential, in which the membrane potential changes rapidly and significantly for a short time (on the order of 1 to 100 milliseconds), often reversing its polarity. Action potentials are generated by the activation of certain voltage-gated ion channels.
JUNQ and IPOD Summary JUNQ_and_IPOD JUNQ and IPOD are types of cytosolic protein inclusion bodies in eukaryotes. Neurodegenerative diseases, such as Parkinson's, Alzheimer's, and Huntington's, are associated and correlated with protein aggregation and accumulation of misfolded proteins in inclusion bodies. For many years, protein aggregation was considered a random process by which misfolded proteins stick to each other to form inclusions (imagine a bundle of hairs haphazardly piling up in a corner of a room). Moreover, protein aggregates were thought to be toxic agents and the cause for neuronal dysfunction and death.
Permutation tests Monte Carlo testing Permutation_tests > Monte Carlo testing In the example above, the confidence interval only tells us that there is roughly a 50% chance that the p-value is smaller than 0.05, i.e. it is completely unclear whether the null hypothesis should be rejected at a level α = 0.05 {\displaystyle \alpha =0.05} . If it is only important to know whether p ≤ α {\displaystyle p\leq \alpha } for a given α {\displaystyle \alpha } , it is logical to continue simulating until the statement p ≤ α {\displaystyle p\leq \alpha } can be established to be true or false with a very low probability of error. Given a bound ϵ {\displaystyle \epsilon } on the admissible probability of error (the probability of finding that p ^ > α {\displaystyle {\widehat {p}}>\alpha } when in fact p ≤ α {\displaystyle p\leq \alpha } or vice versa), the question of how many permutations to generate can be seen as the question of when to stop generating permutations, based on the outcomes of the simulations so far, in order to guarantee that the conclusion (which is either p ≤ α {\displaystyle p\leq \alpha } or p > α {\displaystyle p>\alpha } ) is correct with probability at least as large as 1 − ϵ {\displaystyle 1-\epsilon } .
Reactive synthesis Summary Reactive_synthesis Reactive synthesis (or temporal synthesis) is the field of computer science that studies automatic generation of state machines (e.g. Moore machines) from high-level specifications (e.g. formulas in linear temporal logic). "Reactivity" highlights the fact that the synthesized machine interacts with the user, reading an input and producing an output, and never stops its operation. The synthesis problem was introduced by Alonzo Church in 1962, with specifications being formulas in monadic second-order logic and state machines in the form of digital circuits.
Lyapunov stable Lyapunov's second method for stability Lyapunov's_theory > Definition for continuous-time systems > Lyapunov's second method for stability An additional condition called "properness" or "radial unboundedness" is required in order to conclude global stability. Global asymptotic stability (GAS) follows similarly. It is easier to visualize this method of analysis by thinking of a physical system (e.g. vibrating spring and mass) and considering the energy of such a system.
Integer underflow Explicit propagation Integer_underflow > Methods to address integer overflow problems > Explicit propagation If a value is too large to be stored it can be assigned a special value indicating that overflow has occurred and then have all successive operations return this flag value. Such values are sometimes referred to as NaN, for "not a number". This is useful so that the problem can be checked once at the end of a long calculation rather than after each step. This is often supported in floating-point hardware called FPUs.
Current density In practice Current_density > In practice In transformers designed for high frequencies, loss is reduced if Litz wire is used for the windings. This is made of multiple isolated wires in parallel with a diameter twice the skin depth. The isolated strands are twisted together to increase the total skin area and to reduce the resistance due to skin effects.
Wrapped normal distribution Summary Wrapped_normal_distribution In probability theory and directional statistics, a wrapped normal distribution is a wrapped probability distribution that results from the "wrapping" of the normal distribution around the unit circle. It finds application in the theory of Brownian motion and is a solution to the heat equation for periodic boundary conditions. It is closely approximated by the von Mises distribution, which, due to its mathematical simplicity and tractability, is the most commonly used distribution in directional statistics.
Database encryption Key management Database_encryption > Key management The complexity of key management logistics is also a topic that needs to be taken into consideration. As the number of application that a firm uses increases, the number of keys that need to be stored and managed increases as well. Thus it is necessary to establish a way in which keys from all applications can be managed through a single channel, which is also known as enterprise key management.
Glossary of computer chess terms A–M Glossary_of_computer_chess_terms > A–M bit A binary digit, 0 or 1. The smallest piece of information that can be stored or manipulated by the computer bit board An array of 64 bits, each bit representing a square of the chess board. Multiple bit boards are used with each board recording a particular characteristic, such as all of the squares occupied by a particular type of piece or all squares under attack.
Zygosaccharomyces bailii Morphology and modes of reproduction Zygosaccharomyces_bailii > Morphology and modes of reproduction Zygosaccharomyces bailii vegetative cells are usually ellipsoid, non-motile and reproduced asexually by multilateral budding, i.e. the buds can arise from various sites on the cells. During the budding process, a parent cell produces a bud on its outer surface. As the bud elongates, the parent cell's nucleus divides and one nucleus migrates into the bud. Cell wall material is filled in the gap between the bud and the parent cell; eventually the bud is separated to form a daughter cell of unequal size.
DNA topology Primary structure Nucleic_acid_structure > Primary structure Cytosine, thymine, and uracil are pyrimidines, hence the glycosidic bonds form between their 1 nitrogen and the 1' -OH of the deoxyribose. For both the purine and pyrimidine bases, the phosphate group forms a bond with the deoxyribose sugar through an ester bond between one of its negatively charged oxygen groups and the 5' -OH of the sugar. The polarity in DNA and RNA is derived from the oxygen and nitrogen atoms in the backbone.
Tunnel field-effect transistor Summary Tunnel_field-effect_transistor The tunnel field-effect transistor (TFET) is an experimental type of transistor. Even though its structure is very similar to a metal–oxide–semiconductor field-effect transistor (MOSFET), the fundamental switching mechanism differs, making this device a promising candidate for low power electronics. TFETs switch by modulating quantum tunneling through a barrier instead of modulating thermionic emission over a barrier as in traditional MOSFETs.
Crystallographic point group Schoenflies notation Crystallographic_point_group > Notation > Schoenflies notation Dnd has, in addition to the elements of Dn, mirror planes parallel to the n-fold axis. The letter T (for tetrahedron) indicates that the group has the symmetry of a tetrahedron.
Gran plot Summary Gran_plot These approximations are only valid near, but not at, the end point, and so the method differs from end point estimations by way of first- and second-derivative plots, which require data at the end point. Gran plots were originally devised for graphical determinations in pre-computer times, wherein an x-y plot on paper would be manually extrapolated to estimate the x-intercept. The graphing and visual estimation of the end point have been replaced by more accurate least-squares analyses since the advent of modern computers and enabling software packages, especially spreadsheet programs with built-in least-squares functionality.
Ockham’s razor Richard Swinburne Ockham’s_razor > Justifications > Other philosophers > Richard Swinburne Richard Swinburne argues for simplicity on logical grounds: ... the simplest hypothesis proposed as an explanation of phenomena is more likely to be the true one than is any other available hypothesis, that its predictions are more likely to be true than those of any other available hypothesis, and that it is an ultimate a priori epistemic principle that simplicity is evidence for truth. According to Swinburne, since our choice of theory cannot be determined by data (see Underdetermination and Duhem–Quine thesis), we must rely on some criterion to determine which theory to use. Since it is absurd to have no logical method for settling on one hypothesis amongst an infinite number of equally data-compliant hypotheses, we should choose the simplest theory: "Either science is irrational or the principle of simplicity is a fundamental synthetic a priori truth. ".
Drift racing Drift competition Drift_racing > Drift competition This is why a driver wants to maintain their speed through the large angle. Achieving this correctly judges will give you a higher score. Line - In almost any drifting scene or competition the driver will need to follow a "line".
Temporary satellite Artificial objects on temporary satellite orbits Temporary_satellite > Artificial objects on temporary satellite orbits The Earth can also temporarily capture defunct space probes or rockets travelling on solar orbits, in which case astronomers cannot always immediately determine whether the object is artificial or natural. The possibility of an artificial origin has been considered for both 2006 RH120 and 1991 VG.The artificial origin has been confirmed in other cases. In September 2002, astronomers found an object designated J002E3.
Closest point query Locality sensitive hashing Nearest_neighbor_distance_ratio > Methods > Approximation methods > Locality sensitive hashing Locality sensitive hashing (LSH) is a technique for grouping points in space into 'buckets' based on some distance metric operating on the points. Points that are close to each other under the chosen metric are mapped to the same bucket with high probability.
Mean values Arithmetic mean (AM) Mean_values > Types of means > Pythagorean means > Arithmetic mean (AM) The arithmetic mean (or simply mean) of a list of numbers, is the sum of all of the numbers divided by the number of numbers. Similarly, the mean of a sample x 1 , x 2 , … , x n {\displaystyle x_{1},x_{2},\ldots ,x_{n}} , usually denoted by x ¯ {\displaystyle {\bar {x}}} , is the sum of the sampled values divided by the number of items in the sample. x ¯ = 1 n ( ∑ i = 1 n x i ) = x 1 + x 2 + ⋯ + x n n {\displaystyle {\bar {x}}={\frac {1}{n}}\left(\sum _{i=1}^{n}{x_{i}}\right)={\frac {x_{1}+x_{2}+\cdots +x_{n}}{n}}} For example, the arithmetic mean of five values: 4, 36, 45, 50, 75 is: 4 + 36 + 45 + 50 + 75 5 = 210 5 = 42. {\displaystyle {\frac {4+36+45+50+75}{5}}={\frac {210}{5}}=42.}
Benzo(a)pyrene Interaction with DNA Benzo(a)pyrene > Toxicity > Interaction with DNA Upon binding the transformed receptor translocates to the nucleus where it dimerises with ARNT (aryl hydrocarbon receptor nuclear translocator) and then binds xenobiotic response elements (XREs) in DNA located upstream of certain genes. This process increases transcription of certain genes, notably CYP1A1, followed by increased CYP1A1 protein production.
Intelligent speed assistance Dead reckoning Intelligent_speed_adaptation > Speed and location determination and verification > Dead reckoning By overlaying this path onto a digital map, the DR system knows approximately where the vehicle is, what the local speed limit is, and the speed at which the vehicle is travelling. The system can then use information provided by the digital map to warn of upcoming hazards or points of interest and to provide warnings if the speed limit is exceeded. Dead reckoning is prone to cumulative measurement errors such as variations between the assumed circumference of the tyres compared to the actual dimension (which is used to calculate vehicle speed and distance travelled).
Paired-end tag PET applications Paired-end_tag > PET applications Sequencing the cDNAs can reveal the structures of transcripts in great details, but this approach is much more expensive than RNA-PET sequencing, especially for characterizing the whole transcriptome. The major limitation of RNA-PET is the lack of information regarding the organization of the internal exons of transcripts. Therefore, RNA-PET is not suitable for detecting alternative splicing.
Biological Theory Abstracting and indexing Biological_Theory > Abstracting and indexing The journal is abstracted and indexed in BIOSIS Previews, Biological Abstracts, and The Zoological Record.
Latent tuberculosis Epidemiology Latent_tuberculosis > Epidemiology "In the US, over half of all active TB cases occur in immigrants. The reported cases of active TB in foreign-born persons has remained at 7000–8000 per year, while the number of cases in US-born people has dropped from 17,000 in 1993 to 6,500 in 2005. As a result, the percentage of active TB cases in immigrants has increased steadily (from 29% of all cases in 1993 to 54% in 2005)," and most of those cases are in developing countries.
High-level synthesis Source input Algorithmic_synthesis > Source input The most common source inputs for high-level synthesis are based on standard languages such as ANSI C/C++, SystemC and MATLAB. High-level synthesis typically also includes a bit-accurate executable specification as input, since to derive an efficient hardware implementation, additional information is needed on what is an acceptable Mean-Square Error or Bit-Error Rate etc. For example, if the designer starts with an FIR filter written using the "double" floating type, before he can derive an efficient hardware implementation, they need to perform numerical refinement to arrive at a fixed-point implementation. The refinement requires additional information on the level of quantization noise that can be tolerated, the valid input ranges etc. This bit-accurate specification makes the high level synthesis source specification functionally complete. Normally the tools infer from the high level code a Finite State Machine and a Datapath that implement arithmetic operations.
Hurter–Driffield curve Details Hurter–Driffield_curve > Details Plots of film density (log of opacity) versus the log of exposure are called characteristic curves, Hurter–Driffield curves, H–D curves, HD curves, H & D curves, D–logE curves, or D–logH curves. At moderate exposures, the overall shape is typically a bit like an "S" slanted so that its base and top are horizontal. There is usually a central region of the HD curve which approximates to a straight line, called the "linear" or "straight-line" portion; the slope of this region is called the gamma. The low end is called the "toe", and at the top, the curve rounds over to form the "shoulder".
Web of Trust Summary Web_of_Trust In cryptography, a web of trust is a concept used in PGP, GnuPG, and other OpenPGP-compatible systems to establish the authenticity of the binding between a public key and its owner. Its decentralized trust model is an alternative to the centralized trust model of a public key infrastructure (PKI), which relies exclusively on a certificate authority (or a hierarchy of such). As with computer networks, there are many independent webs of trust, and any user (through their public key certificate) can be a part of, and a link between, multiple webs.
Organoactinide chemistry Organometallic complexes with σ-bonding Organoactinide_chemistry > Organometallic complexes with σ-bonding Most common organoactinide complexes involve π-bonding with ligands such as cyclopentadienyl, but there are a few exceptions with σ-bonding, namely in thorium and uranium chemistry as these are the most easily handleable elements of this group.
Silent auction Terminology Rank_auction > Terminology If the lot is for a group of items, the price paid is for the entire lot and the winning bidder must take all the items sold. Variants on a group lot bid include "choice" and "times the money" (see definitions for each). Example: An auction has five bath fragrance gift baskets where bidding is "lot", and the hammer price is $5.
Computer-human interaction Principles based on attention Human-computer_interactions > Display designs > Thirteen principles of display design > Principles based on attention 8. Minimizing information access cost or interaction cost. When the user's attention is diverted from one location to another to access necessary information, there is an associated cost in time or effort. A display design should minimize this cost by allowing frequently accessed sources to be located at the nearest possible position.
Material point method The algorithm Material_point_method > The algorithm An MPM simulation consists of the following stages: (Prior to the time integration phase) Initialization of grid and material points. A geometry is discretized into a collection of material points, each with its own material properties and initial conditions (velocity, stress, temperature, etc.) The grid, being only used to provide a place for gradient calculations is normally made to cover an area large enough to fill the expected extent of computational domain needed for the simulation. (During the time integration phase - explicit formulation) Material point quantities are extrapolated to grid nodes. Material point mass ( m m p {\textstyle m_{mp}} ), momenta ( P m p → {\textstyle {\vec {P_{mp}}}} ), stresses ( σ ¯ ¯ m p {\displaystyle {\boldsymbol {\bar {\bar {\sigma }}}}_{mp}} ), and external forces ( b → {\displaystyle {\vec {b}}} ) are extrapolated to the nodes at the corners of the cells within which the material points reside.
Data independence First Level of Data Independence Physical_data_independence > First Level of Data Independence The logical structure of the data is known as the 'schema definition'. In general, if a user application operates on a subset of the attributes of a relation, it should not be affected later when new attributes are added to the same relation. Logical data independence indicates that the conceptual schema can be changed without affecting the existing schemas.
Ontology chart Overview Ontology_chart > Overview The nodes of an ontology chart represent universal affordances and rarely represent particulars. The exception is the root which is a particular agent often labelled ‘society’ and located on the extreme left of an ontology chart. The root is often dropped in practice but is implied in every ontology chart. If any other particular is present in an ontology chart it is recognised by the ‘#’ sign prefix and upper case letters.
Clonal selection Theories supported by clonal selection Clonal_selection_theory > Theories supported by clonal selection If non-self tissue is introduced, lymphocytes that develop are the ones that include the non-self tissues as self tissue. In 1959, Burnet proposed that under certain circumstances, tissues could be successfully transplanted into foreign recipients. This work has led to a much greater understanding of the immune system and also great advances in tissue transplantation.
Linear time-invariant system Z and discrete-time Fourier transforms Linear_time-invariant_system > Discrete-time systems > Z and discrete-time Fourier transforms The eigenfunction property of exponentials is very useful for both analysis and insight into LTI systems. The Z transform is exactly the way to get the eigenvalues from the impulse response. Of particular interest are pure sinusoids; i.e. exponentials of the form e j ω n {\displaystyle e^{j\omega n}} , where ω ∈ R {\displaystyle \omega \in \mathbb {R} } . These can also be written as z n {\displaystyle z^{n}} with z = e j ω {\displaystyle z=e^{j\omega }} .
Z88 FEM software Overview Z88_FEM_software > History and functionalities > Overview The software was developed by Frank Rieg, a professor for engineering design and CAD at the University of Bayreuth. Originally written in FORTRAN 77, the program was ported to the programming language C in the early 1990s. There are two programs for finite element analysis: Z88OS (current version 15.0) is available as free software including the source code under the GNU General Public License. Due to the modular structure of the program and the open availability of the source code it is possible to develop customized extensions and add-ons and several special case 2D and 3D continuum elements (e.g. anisotropic shell element) were developed by users.
Ecophenotypic variation Animals Ecophenotypic_variation > Animals Mutations to the genes are the only source of genetic variation. In sexual reproduction, each parent contributes half of his or her genome to the offspring; thus the offspring contain a mixture of genetic material. Adaptations are traits that increase fitness, the driving force for natural selection.
Dynamic equilibrium Relationship between equilibrium and rate constants Dynamic_equilibrium > Relationship between equilibrium and rate constants {\textstyle t\gtrapprox {\frac {10}{k_{f}+k_{b}}}.} Since the concentrations do not change thereafter, they are, by definition, equilibrium concentrations. Now, the equilibrium constant for the reaction is defined as K = eq eq {\displaystyle K={\frac {_{\text{eq}}}{_{\text{eq}}}}} It follows that the equilibrium constant is numerically equal to the quotient of the rate constants. K = k f k f + k b 0 k b k f + k b 0 = k f k b {\displaystyle K={\frac {{\frac {k_{f}}{k_{f}+k_{b}}}_{0}}{{\frac {k_{b}}{k_{f}+k_{b}}}_{0}}}={\frac {k_{f}}{k_{b}}}} In general they may be more than one forward reaction and more than one backward reaction. Atkins states that, for a general reaction, the overall equilibrium constant is related to the rate constants of the elementary reactions by K = ( k f k b ) 1 × ( k f k b ) 2 × ⋯ {\displaystyle K=\left({\frac {k_{f}}{k_{b}}}\right)_{1}\times \left({\frac {k_{f}}{k_{b}}}\right)_{2}\times \cdots }
Linear hashing File contraction Linear_hashing > Algorithm details > File contraction If under controlled splitting the load factor sinks below a threshold, a merge operation is triggered. The merge operation undoes the last split, also resetting the file state.
Pyruvate dehydrogenase complex 3D structures Pyruvate_dehydrogenase_complex > External links > 3D structures 98 (26): 14802–14807. Bibcode:2001PNAS...9814802Z. doi:10.1073/pnas.011597698.
Human kidney Function Kidney > Function The kidneys excrete a variety of waste products produced by metabolism into the urine. The microscopic structural and functional unit of the kidney is the nephron. It processes the blood supplied to it via filtration, reabsorption, secretion and excretion; the consequence of those processes is the production of urine. These include the nitrogenous wastes urea, from protein catabolism, and uric acid, from nucleic acid metabolism.
Common lymphoid progenitor Terminology Common_lymphoid_progenitor > Terminology But science is an additive game, and it was eventually found these progenitors were not unique, and further that the two great families of myeloid and lymphoid were not disjoint, but rather two partially interwoven family trees. This is more than just nomenclature, it is new science that provides challenges of complexity yet offers new vistas of bio-science and the promise of early enhancement of private and public health issues. And it gives insight into the nature of redundancy and overlap in the immune system and hints how to use this to advantage.
Subquadratic time Summary Logarithmic_time In computer science, the time complexity is the computational complexity that describes the amount of computer time it takes to run an algorithm. Time complexity is commonly estimated by counting the number of elementary operations performed by the algorithm, supposing that each elementary operation takes a fixed amount of time to perform. Thus, the amount of time taken and the number of elementary operations performed by the algorithm are taken to be related by a constant factor. Since an algorithm's running time may vary among different inputs of the same size, one commonly considers the worst-case time complexity, which is the maximum amount of time required for inputs of a given size.
Multiple sclerosis research Treatments Multiple_sclerosis_research > Treatments Moreover, synergies, in which a drug potentiates the effect of another are also possible. Nevertheless, there can also appear important drawbacks such as antagonizing mechanisms of action or potentiation of deleterious secondary effects. While there have been several clinical trials of combined therapy none has shown positive enough effects to merit the consideration as a viable treatment for MS.Regarding neuroprotective and regenerative treatments such as stem cell therapy, while their research is considered of high importance at the moment they are only a promise of future therapeutic approaches. Likewise, there are not any effective treatments for the progressive variants of the disease. Many of the newest drugs as well as those under development are probably going to be evaluated as therapies for PPMS or SPMS, and their improved effectiveness when compared with previously existing drugs may eventually lead to a positive result in these groups of patients.
Aether theories Quantum vacuum Aether_theories > Non-standard interpretations in modern physics > Quantum vacuum Quantum mechanics can be used to describe spacetime as being non-empty at extremely small scales, fluctuating and generating particle pairs that appear and disappear incredibly quickly. It has been suggested by some such as Paul Dirac that this quantum vacuum may be the equivalent in modern physics of a particulate aether. However, Dirac's aether hypothesis was motivated by his dissatisfaction with quantum electrodynamics, and it never gained support from the mainstream scientific community.Physicist Robert B. Laughlin wrote: It is ironic that Einstein's most creative work, the general theory of relativity, should boil down to conceptualizing space as a medium when his original premise was that no such medium existed The word 'ether' has extremely negative connotations in theoretical physics because of its past association with opposition to relativity. This is unfortunate because, stripped of these connotations, it rather nicely captures the way most physicists actually think about the vacuum.
Quality of service IP and Ethernet efforts Quality_of_service > Mechanisms > IP and Ethernet efforts Typically, some bandwidth is allocated by default to network control packets (such as Internet Control Message Protocol and routing protocols), while best-effort traffic might simply be given whatever bandwidth is left over. At the Media Access Control (MAC) layer, VLAN IEEE 802.1Q and IEEE 802.1p can be used to distinguish between Ethernet frames and classify them. Queueing theory models have been developed on performance analysis and QoS for MAC layer protocols.Cisco IOS NetFlow and the Cisco Class Based QoS (CBQoS) Management Information Base (MIB) are marketed by Cisco Systems.
Hilbert spaces Partial differential equations Hilbert_Space > Applications > Partial differential equations For linear elliptic equations, one geometrical result that ensures unique solvability for a large class of problems is the Lax–Milgram theorem. This strategy forms the rudiment of the Galerkin method (a finite element method) for numerical solution of partial differential equations.A typical example is the Poisson equation −Δu = g with Dirichlet boundary conditions in a bounded domain Ω in R2. The weak formulation consists of finding a function u such that, for all continuously differentiable functions v in Ω vanishing on the boundary: This can be recast in terms of the Hilbert space H10(Ω) consisting of functions u such that u, along with its weak partial derivatives, are square integrable on Ω, and vanish on the boundary.

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