Scientific News

Articles across mathematics, physics, chemistry, biology, and astronomy.

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  Science

  Irreversible process

  In thermodynamics, an irreversible process is a process impossible to reverse or undo. All complex natural processes are irreversible, although a phase transition at the coexistence temperature (e.g. melting of ice cubes in water) is well approximated as reversible. A change in the thermodynamic state of a system and all of its surroundings cannot be precisely restored to its initial state by infi

  8/24/2026

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  Irreducibility (mathematics)

  In mathematics, the concept of irreducibility is used in several ways. A polynomial over a field may be an irreducible polynomial if it cannot be factored over that field. In abstract algebra, irreducible can be an abbreviation for irreducible element of an integral domain; for example an irreducible polynomial. In representation theory, an irreducible representation is a nontrivial representatio

  8/24/2026

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  Isohydric principle

  The isohydric principle is the phenomenon whereby multiple acid/base pairs in solution will be in equilibrium with one another, tied together by their common reagent: the hydrogen ion and hence, the pH of solution. That is, when several buffers are present together in the same solution, they are all exposed to the same hydrogen ion activity. Hence, the pK of each buffer will dictate the ratio of t

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  Science

  Ishango bone

  The Ishango bone, discovered at the "Fisherman Settlement" of Ishango in the Democratic Republic of the Congo, is a bone tool and possible mathematical device that dates to the Upper Paleolithic era. The curved bone is dark brown in color, about 10 centimeters in length, and features a sharp piece of quartz affixed to one end, perhaps for engraving. Because the bone has been narrowed, scraped, pol

  8/24/2026

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  Science

  Irrationality measure

  In mathematics, an irrationality measure of a real number x {\displaystyle x} is a measure of how "closely" it can be approximated by rationals. If a function f ( t , λ ) {\displaystyle f(t,\lambda )} , defined for t , λ >

  8/24/2026

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  Isochore (genetics)

  In genetics, an isochore is a large region of genomic DNA (greater than 300 kilobases) with a high degree of uniformity in GC content; that is, guanine (G) and cytosine (C) bases. The distribution of bases within a genome is non-random: different regions of the genome have different amounts of G-C base pairs, such that regions can be classified and identified by the proportion of G-C base pairs th

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  Science

  Iron stress repressed RNA

  Iron stress repressed RNA (IsrR) is a cis-encoded antisense RNA which regulates the expression of the photosynthetic protein isiA. In other words, IsrR is located in the bacteria which serves as a regulator RNA that helps the bacteria adapt to an iron limited environment within the host. IsiA expression is activated by the Ferric uptake regulator protein (Fur) under iron stress conditions. IsiA en

  8/24/2026

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  Island ecology

  Island ecology is the study of island organisms and their interactions with each other and the environment. Islands account for nearly 1/6 of earth's total land area, yet the ecology of island ecosystems is vastly different from that of mainland communities. Their isolation and high availability of empty niches lead to increased speciation. As a result, island ecosystems comprise 30% of the wor

  8/24/2026

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  Ischemic cell death

  Ischemic cell death, or oncosis, is a form of accidental cell death. The process is characterized by an ATP depletion within the cell leading to impairment of ionic pumps, cell swelling, clearing of the cytosol, dilation of the endoplasmic reticulum and golgi apparatus, mitochondrial condensation, chromatin clumping, and cytoplasmic bleb formation. Oncosis refers to a series of cellular reactions

  8/24/2026

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  Isodrin

  Isodrin may refer to either of two chemical compounds: Isodrin, an organochlorine insecticide which is an isomer of aldrin Pholedrine (4-HMA), a methylamphetamine derivative

  8/24/2026

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  Isotopes in medicine

  A medical isotope is an isotope used in medicine. The first uses of isotopes in medicine were in radiopharmaceuticals, and this is still the most common use. However more recently, separated stable isotopes have come into use.

  8/24/2026

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  Isoazimuth

  The isoazimuth is the locus of the points on the Earth's surface whose initial orthodromic course with respect to a fixed point is constant. That is, if the initial orthodromic course Z from the starting point S to the fixed point X is 80 degrees, the associated isoazimuth is formed by all points whose initial orthodromic course with respect to point X is 80° (with respect to true north). The iso

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  Science

  Isotope effect on lipid peroxidation

  Kinetic isotope effect is observed when molecules containing heavier isotopes of the same elements (for example, deuterium for hydrogen) engage in a chemical reaction at a slower rate. Deuterium-reinforced lipids can be used for protecting living cells by slowing the chain reaction of lipid peroxidation. The lipid bilayer of the cell and organelle membranes contain polyunsaturated fatty acids (PUF

  8/24/2026

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  Isolume

  Isolumes are the preferred light zone of an organism in the ocean in the preferendum hypothesis. The preferendum hypothesis suggests that some organisms living in the mesopelagic zone, change their depth as light levels change in order to remain in their isolume. Organisms prefer to remain within a certain light level for a variety of reason. Some organisms, like Sergestidae, Euphausiid, and Palin

  8/24/2026

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  Iridium bromide

  Iridium bromide may refer to: Iridium(IV) bromide (iridium tetrabromide), IrBr4 Iridium(III) bromide (iridium tribromide), IrBr3

  8/24/2026

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  Iron iodide

  Iron iodide may refer to: Iron(II) iodide (ferrous iodide, iron diiodide), FeI2 Iron(III) iodide (ferric iodide, iron triiodide), FeI3, unstable

  8/24/2026

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  Iron perchlorate

  Iron perchlorate may refer to: Iron(II) perchlorate, Fe(NO3)2, a green compound Iron(III) perchlorate (or ferric perchlorate), Fe(NO3)3, a pale violet compound

  8/24/2026

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  Iron cyanide

  Iron cyanide may refer to: Iron(I) cyanide, FeCN Iron(II) cyanide, Fe(CN)2 Ferrocyanide, [Fe(CN)6]4− Ferricyanide, [Fe(CN)6]3−

  8/24/2026

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  Introduction to electromagnetism

  Electromagnetism is one of the fundamental forces of nature. Early on, electricity and magnetism were studied separately and regarded as separate phenomena. Hans Christian Ørsted discovered that the two were related – electric currents give rise to magnetism. Michael Faraday discovered the converse, that magnetism could induce electric currents, and James Clerk Maxwell put the whole thing toget

  8/24/2026

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  Science

  Interstellar medium

  The interstellar medium (ISM) is the matter and radiation that exists in the space between the star systems in a galaxy. This matter includes gas in ionic, atomic, and molecular form, as well as dust and cosmic rays. It fills interstellar space and blends smoothly into the surrounding intergalactic medium. The energy that occupies the same volume, in the form of electromagnetic radiation, is the i

  8/24/2026

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  Intrinsic parity

  In quantum mechanics, the intrinsic parity is a phase factor that arises as an eigenvalue of the parity operation x i → x i ′ = − x i {\displaystyle

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  Intramolecular reaction

  In chemistry, intramolecular describes a process or characteristic limited within the structure of a single molecule, a property or phenomenon limited to the extent of a single molecule.

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  Science

  Intersystem crossing

  Intersystem crossing (ISC) is an isoenergetic radiationless process involving a transition between the two electronic states with different spin multiplicity.

  8/24/2026

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  Inversion recovery

  Inversion recovery is a magnetic resonance imaging sequence that provides high contrast between tissue and lesion. It can be used to provide high T1 weighted image, high T2 weighted image, and to suppress the signals from fat, blood, or cerebrospinal fluid.

  8/24/2026

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  Science

  Interplanetary medium

  The interplanetary medium (IPM) or interplanetary space consists of the mass and energy which fills the Solar System, and through which all the larger Solar System bodies, such as planets, dwarf planets, asteroids, and comets, move. The IPM stops at the heliopause, outside of which the interstellar medium begins. Before 1950, interplanetary space was widely considered to either be an empty vacuum,

  8/24/2026

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  Interventionism (medicine)

  Interventionism, when discussing the practice of medicine, is generally a derogatory term used by critics of a medical model in which patients are viewed as passive recipients receiving external treatments provided by the physician that have the effect of prolonging life, or at least of providing a subjective sense of doing everything possible. Interventionism is commonly encouraged by terminally

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  Intraspecific competition

  Intraspecific competition is an interaction in population ecology, whereby members of the same species compete for limited resources. This leads to a reduction in fitness for both individuals, but the more fit individual survives and is able to reproduce. By contrast, interspecific competition occurs when members of different species compete for a shared resource. Members of the same species have

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  Science

  Intracluster medium

  In astronomy, the intracluster medium (ICM) is the superheated plasma that permeates a galaxy cluster. The gas consists mainly of ionized hydrogen and helium and accounts for most of the baryonic material in galaxy clusters. The ICM is heated to temperatures on the order of 10 to 100 megakelvins, emitting strong X-ray radiation.

  8/24/2026

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  Intersubband polariton

  Intersubband transitions (also known as intraband transitions) are dipolar allowed optical excitations between the quantized electronic energy levels within the conduction band of semiconductor heterostructures. Intersubband transitions when coupled with an optical resonator form new, mixed-state photons. This mixing is referred to as an intersubband cavity-polariton. These transitions exhibit an

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  Science

  Interspecific competition

  Interspecific competition, in ecology, is a form of competition in which individuals of different species compete for the same resources in an ecosystem (e.g. food or living space). This can be contrasted with mutualism, a type of symbiosis. Competition between members of the same species is called intraspecific competition. If a tree species in a dense forest grows taller than surrounding tree sp

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  Interplanetary magnetic field

  The interplanetary magnetic field (IMF), also commonly referred to as the heliospheric magnetic field (HMF), is the component of the solar magnetic field that is dragged out from the solar corona by the solar wind flow to fill the Solar System.

  8/24/2026

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  Science

  Intraguild predation

  Intraguild predation, or IGP, is the killing and sometimes eating of a potential competitor of a different species. This interaction represents a combination of predation and competition, because both species rely on the same prey resources and also benefit from preying upon one another. Intraguild predation is common in nature and can be asymmetrical, in which one species feeds upon the other,

  8/24/2026

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  Interrupt coalescing

  Interrupt coalescing, also known as interrupt moderation, is a technique in which events which would normally trigger a hardware interrupt are held back, either until a certain amount of work is pending, or a timeout timer triggers. Used correctly, this technique can reduce interrupt load by up to an order of magnitude, while only incurring relatively small latency penalties. Interrupt coalescing

  8/24/2026

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  Interspecies hydrogen transfer

  Interspecies hydrogen transfer (IHT) is a form of interspecies electron transfer. It is a syntrophic process by which H2 is transferred from one organism to another, particularly in the rumen and other anaerobic environments. IHT was discovered between Methanobacterium bryantii strain M.o.H and an "S" organism in 1967 by Marvin Bryant, Eileen Wolin, Meyer Wolin, and Ralph Wolfe at the University o

  8/24/2026

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  Interscript

  Interscript was a rich text document markup language designed by Xerox to act as a common interchange format between disparate document formats. It was part of a system that included the Xerox Character Code Standard (XCCS) and the InterPress page description representation.

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  Introduction to Electrodynamics

  Introduction to Electrodynamics is a textbook by physicist David J. Griffiths. Generally regarded as a standard undergraduate text on the subject, it began as lecture notes that have been perfected over time. Its most recent edition, the fifth, was published in 2023 by Cambridge University Press. This book uses SI units (what it calls the mks convention) exclusively. A table for converting between

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  Science

  Intravenous ascorbic acid

  Intravenous Ascorbic Acid (also known as vitamin C or L-ascorbic acid), is a process that delivers soluble ascorbic acid directly into the bloodstream. It is not approved for use to treat any medical condition. The use of intravenous ascorbic acid as a proposed cancer treatment or co-treatment has been a controversial topic since the emergence of misleading data in the 1970s.

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  Science

  Intersex (biology)

  Intersex is a general term for an organism that has sex characteristics that are between male and female. It typically applies to a minority of members of gonochoric animal species such as mammals (as opposed to hermaphroditic species in which the majority of members can have both male and female sex characteristics). Such organisms are usually sterile. Intersexuality can occur due to both genetic

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  Science

  Intersex healthcare

  People with intersex variations, also called disorders of sex development, have hormonal, genetic, or anatomical differences unexpected of an endosex (non-intersex) male or female. These can include, but are not limited to, reproductive organs with a mix of male and female structures, underdeveloped reproductive organs, and rare sex chromosomes or chromosomes unexpected of one's sex. The healthcar

  8/24/2026

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  Intrinsic DNA fluorescence

  Intrinsic DNA fluorescence is the fluorescence emitted directly by DNA when it absorbs ultraviolet (UV) radiation. It contrasts to that stemming from fluorescent labels that are either simply bound to DNA or covalently attached to it, widely used in biological applications; such labels may be chemically modified, not naturally occurring, nucleobases. The intrinsic DNA fluorescence was discovered i

  8/24/2026

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  Intuitionism

  In philosophy of mathematics, intuitionism, or neointuitionism (opposed to preintuitionism), is an approach where mathematics is considered to be purely the result of the constructive mental activity of humans rather than the discovery of fundamental principles claimed to exist in an objective reality. That is, logic and mathematics are not considered analytic activities wherein deep properties of

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  Inverse parser

  An inverse parser, as its name suggests, is a parser that works in reverse. Rather than the user typing into the computer, the computer presents a list of words fitting the context, and excludes words that would be unreasonable. This ensures the user knows all of their options. The concept and an implementation were originally developed and patented by Texas Instruments. A few years later, it was

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  Science

  Invariant (mathematics)

  In mathematics, an invariant is a property of a mathematical object (or a class of mathematical objects) which remains unchanged after operations or transformations of a certain type are applied to the objects. The particular class of objects and type of transformations are usually indicated by the context in which the term is used. For example, the area of a triangle is an invariant with respect

  8/24/2026

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  Invariable plane

  The invariable plane of a planetary system, also called Laplace's invariable plane, is the plane passing through its barycenter (center of mass) perpendicular to its angular momentum vector.

  8/24/2026

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  Introduction to quantum mechanics

  Quantum mechanics is the study of matter and matter's interactions with energy on the scale of atomic and subatomic particles. By contrast, classical physics explains matter and energy only on a scale familiar to human experience, including the behavior of astronomical bodies such as the Moon. Classical physics is still used in much of modern science and technology. However, towards the end of the

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  Iodobenzenes

  Iodobenzenes are a group of aryl iodides/halobenzenes consisting of one or more iodine atoms as substituents on a benzene core. They have the formula C6H6–nIn, where n = 1–6 is the number of iodine atoms. Depending on the number of iodine substituents, there may be several constitutional isomers possible. Monoiodobenzene Diiodobenzene 1,2-Diiodobenzene 1,3-Diiodobenzene 1,4-Diiodobenzene Triiodob

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  Science

  Introduction to genetics

  Genetics is the study of genes and tries to explain what they are and how they work. Genes are how living organisms inherit features or traits from their ancestors; for example, children usually look like their parents because they have inherited their parents' genes. Genetics tries to identify which traits are inherited and to explain how these traits are passed from generation to generation. Som

  8/24/2026

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  Ion drift meter

  An ion drift meter is a device used to measure the velocity of individual ions in the area of a spacecraft. This information can then be used to calculate the ion drift in the space surrounding the instrument as well as the strength of an electric field present, provided that the magnetic field strength has been determined using a magnetometer. The device itself works by allowing ions to pass thro

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  Ionized jewelry

  An Ionized bracelet, or ionic bracelet, is a type of metal bracelet jewelry purported to affect the chi of the wearer. No claims of effectiveness made by manufacturers have ever been substantiated by independent sources, and the US Federal Trade Commission (FTC) has found the bracelets are "part of a scheme devised to defraud". Q-Ray, Balance, Bio-Ray, iRenew, Rayma, and Rico's Bio-Energy brand b

  8/24/2026

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  Iridium chloride

  Iridium chloride is a group of inorganic chemical compounds of iridium metal and chlorine. The term can refer to: Iridium(III) chloride (iridium trichloride), IrCl3 Iridium tetrachloride (iridium(IV) chloride), IrCl4 Iridium dichloride (iridium(II) chloride), IrCl2

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