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The earliest barometers were simply glass tubes that were closed at one end and filled with mercury. The tube was then inverted and its open end was submerged in a cup of mercury. The mercury then drained out of the tube until the pressure of the mercury in the tube — as measured at the surface of the mercury in the cup — equaled the atmosphere's pressure on the same surface.
In order to produce barometric light, the glass tube must be very clean and the mercury must be pure. If the barometer is then shaken, a band of light will appear on the glass at the meniscus of the mercury whenever the mercury moves downward.
When mercury contacts glass, the mercury transfers electrons to the glass. Whenever the mercury pulls free of the glass, these electrons are released from the glass into the surroundings, where they collide with gas molecules, causing the gas to glow — just as the collision of electrons and neon atoms causes a neon lamp to glow. | 0 | Luminescence |
Photocytes are found distributed unevenly near the plate cilia cells. Gastric cells form a barrier that keep the photocytes away from the opening of the radially canal which they are found to exist along. | 1 | Bioluminescence |
Zinc sulfide phosphors are used with radioactive materials, where the phosphor was excited by the alpha- and beta-decaying isotopes, to create luminescent paint for dials of watches and instruments (radium dials). Between 1913 and 1950 radium-228 and radium-226 were used to activate a phosphor made of silver doped zinc sulfide (ZnS:Ag), which gave a greenish glow. The phosphor is not suitable to be used in layers thicker than 25 mg/cm, as the self-absorption of the light then becomes a problem. Furthermore, zinc sulfide undergoes degradation of its crystal lattice structure, leading to gradual loss of brightness significantly faster than the depletion of radium. ZnS:Ag coated spinthariscope screens were used by Ernest Rutherford in his experiments discovering atomic nucleus.
Copper doped zinc sulfide (ZnS:Cu) is the most common phosphor used and yields blue-green light. Copper and magnesium doped zinc sulfide yields yellow-orange light.
Tritium is also used as a source of radiation in various products utilizing tritium illumination. | 0 | Luminescence |
Strontium aluminate phosphors produce green and aqua hues, where green gives the highest brightness and aqua the longest glow time. Different aluminates can be used as the host matrix. This influences the wavelength of emission of the europium ion, by its covalent interaction with surrounding oxygens, and crystal field splitting of the 5d orbital energy levels.
The excitation wavelengths for strontium aluminate range from 200 to 450 nm, and the emission wavelengths range from 420 to 520 nm. The wavelength for its green formulation is 520 nm, its aqua, or blue-green, version emits at 505 nm, and its blue emits at 490 nm. Strontium aluminate can be formulated to phosphoresce at longer (yellow to red) wavelengths as well, though such emission is often dimmer than that of more common phosphorescence at shorter wavelengths.
For europium-dysprosium doped aluminates, the peak emission wavelengths are 520 nm for , 480 nm for , and 400 nm for .
is important as a persistently luminescent phosphor for industrial applications. It can be produced by molten salt assisted process at 900 °C.
The most described type is the stoichiometric green-emitting (approx. 530 nm) . shows significantly longer afterglow than the europium-only doped material. The Eu dopant shows high afterglow, while Eu has almost none. Polycrystalline is used as a green phosphor for plasma displays, and when doped with praseodymium or neodymium it can act as a good active laser medium. is a phosphor emitting at 305 nm, with quantum efficiency of 70%. Several strontium aluminates can be prepared by the sol-gel process.
The wavelengths produced depend on the internal crystal structure of the material. Slight modifications in the manufacturing process (the type of reducing atmosphere, small variations of stoichiometry of the reagents, addition of carbon or rare-earth halides) can significantly influence the emission wavelengths.
Strontium aluminate phosphor is usually fired at about 1250 °C, though higher temperatures are possible. Subsequent exposure to temperatures above 1090 °C is likely to cause loss of its phosphorescent properties. At higher firing temperatures, the undergoes transformation to .
Cerium and manganese doped strontium aluminate shows intense narrowband (22 nm wide) phosphorescence at 515 nm when excited by ultraviolet radiation (253.7 nm mercury emission line, to lesser degree 365 nm). It can be used as a phosphor in fluorescent lamps in photocopiers and other devices. A small amount of silicon substituting the aluminium can increase emission intensity by about 5%; the preferred composition of the phosphor is .
However, the material has high hardness, causing abrasion to the machinery used in processing it; manufacturers frequently coat the particles with a suitable lubricant when adding them to a plastic. Coating also prevents the phosphor from water degradation over time.
The glow intensity depends on the particle size; generally, the bigger the particles, the better the glow.
Strontium aluminate is insoluble in water and has an approximate pH of 8 (very slightly basic). | 0 | Luminescence |
There are many GFP-like proteins that, despite being in the same protein family as GFP, are not directly derived from Aequorea victoria. These include dsRed, eqFP611, Dronpa, TagRFPs, KFP, EosFP/IrisFP, Dendra, and so on. Having been developed from proteins in different organisms, these proteins can sometimes display unanticipated approaches to chromophore formation. Some of these, such as KFP, are developed from naturally non- or weakly-fluorescent proteins to be greatly improved upon by mutagenesis. When GFP-like barrels of different spectra characteristics are used, the excitation spectra of one chromophore can be used to power another chromophore (FRET), allowing for conversion between wavelengths of light.
FMN-binding fluorescent proteins (FbFPs) were developed in 2007 and are a class of small (11–16 kDa), oxygen-independent fluorescent proteins that are derived from blue-light receptors. They are intended especially for the use under anaerobic or hypoxic conditions, since the formation and binding of the Flavin chromophore does not require molecular oxygen, as it is the case with the synthesis of the GFP chromophore.
Fluorescent proteins with other chromophores, such as UnaG with bilirubin, can display unique properties like red-shifted emission above 600 nm or photoconversion from a green-emitting state to a red-emitting state. They can have excitation and emission wavelengths far enough apart to achieve conversion between red and green light.
A new class of fluorescent protein was evolved from a cyanobacterial (Trichodesmium erythraeum) phycobiliprotein, α-allophycocyanin, and named small ultra red fluorescent protein (smURFP) in 2016. smURFP autocatalytically self-incorporates the chromophore biliverdin without the need of an external protein, known as a lyase. Jellyfish- and coral-derived GFP-like proteins require oxygen and produce a stoichiometric amount of hydrogen peroxide upon chromophore formation. smURFP does not require oxygen or produce hydrogen peroxide and uses the chromophore, biliverdin. smURFP has a large extinction coefficient (180,000 M cm) and has a modest quantum yield (0.20), which makes it comparable biophysical brightness to eGFP and ~2-fold brighter than most red or far-red fluorescent proteins derived from coral. smURFP spectral properties are similar to the organic dye Cy5.
Reviews on new classes of fluorescent proteins and applications can be found in the cited reviews. | 1 | Bioluminescence |
In phosphors and scintillators, the activator is the element added as dopant to the crystal of the material to create desired type of nonhomogeneities.
In luminescence, only a small fraction of atoms, called emission centers or luminescence centers, emit light. In inorganic phosphors, these inhomogeneities in the crystal structure are created usually by addition of a trace amount of dopants, impurities called activators. (In rare cases dislocations or other crystal defects can play the role of the impurity.) The wavelength emitted by the emission center is dependent on the atom itself, its electronic configuration, and on the surrounding crystal structure.
The activators prolong the emission time (afterglow). In turn, other materials (such as nickel) can be used to quench the afterglow and shorten the decay part of the phosphor emission characteristics.
The electronic configuration of the activator depends on its oxidation state and is crucial for the light emission. Oxidation of the activator is one of the common mechanisms of phosphor degradation. The distribution of the activator in the crystal is also of high importance. Diffusion of the ions can cause depletion of the crystal from the activators with resulting loss of efficiency. This is another mechanism of phosphor degradation.
The scintillation process in inorganic materials is due to the electronic band structure found in the crystals. An incoming particle can excite an electron from the valence band to either the conduction band or the exciton band (located just below the conduction band and separated from the valence band by an energy gap). This leaves an associated hole behind, in the valence band. Impurities create electronic levels in the forbidden gap. The excitons are loosely bound electron-hole pairs which wander through the crystal lattice until they are captured as a whole by impurity centers. The latter then rapidly de-excite by emitting scintillation light (fast component). In case of inorganic scintillators, the activator impurities are typically chosen so that the emitted light is in the visible range or near-UV where photomultipliers are effective. The holes associated with electrons in the conduction band are independent from the latter. Those holes and electrons are captured successively by impurity centers exciting certain metastable states not accessible to the excitons. The delayed de-excitation of those metastable impurity states, slowed by reliance on the low-probability forbidden mechanism, again results in light emission (slow component).
The activator is the main factor determining the phosphor emission wavelength. The nature of the host crystal can however to some degree influence the wavelength as well.
More activators can be used simultaneously.
Common examples of activators are:
* Copper, added in concentration of 5 ppm to copper-activated zinc sulfide, used in glow in the dark materials and green CRT phosphors; long afterglow
* Silver, added to zinc sulfide to produce a phosphor/scintillator used in radium dials, spinthariscopes, and as a common blue phosphor in color CRTs, and to zinc sulfide-cadmium sulfide used as a phosphor in black-and-white CRTs (where the ratio determines the blue/yellow balance of the resulting white); short afterglow
* Europium(II), added to strontium aluminate, used in high-performance glow in the dark materials, very long afterglow; with other host materials it is frequently used as the red emitter in color CRTs and fluorescent lights.
* Cerium, added to yttrium aluminium garnet used in white light emitting diodes, excited by blue light and emitting yellow
* Thallium, used in sodium iodide and caesium iodide scintillator crystals for detection of gamma radiation and for gamma spectroscopy
A newly discovered activator is Samarium(II), added to calcium fluoride. Sm(II) is one of the few materials reported which offers efficient scintillation in the red region of the spectrum, particularly when cooled by dry ice. | 0 | Luminescence |
Many stilbene derivatives (stilbenoids) are present naturally in plants. An example is resveratrol and its cousin, pterostilbene. | 0 | Luminescence |
Luciferins are a class of small-molecule substrates that react with oxygen in the presence of a luciferase (an enzyme) to release energy in the form of light. It is not known just how many types of luciferins there are, but some of the better-studied compounds are listed below.
Because of the chemical diversity of luciferins, there is no clear unifying mechanism of action, except that all require molecular oxygen, The variety of luciferins and luciferases, their diverse reaction mechanisms and the scattered phylogenetic distribution indicate that many of them have arisen independently in the course of evolution. | 1 | Bioluminescence |
The first type of photocyte granule has been found to contain between two and twelve microtubules. In addition, the matrix of the type I granule lacks a uniform shape or structure with ferritin distributed throughout. | 1 | Bioluminescence |
The most common electroluminescent (EL) devices are composed of either powder (primarily used in lighting applications) or thin films (for information displays.) | 0 | Luminescence |
After the discovery of the lux operon, the use of bioluminescent bacteria as a laboratory tool is claimed to have revolutionized the area of environmental microbiology. The applications of bioluminescent bacteria include biosensors for detection of contaminants, measurement of pollutant toxicity and monitoring of genetically engineered bacteria released into the environment. Biosensors, created by placing a lux gene construct under the control of an inducible promoter, can be used to determine the concentration of specific pollutants. Biosensors are also able to distinguish between pollutants that are bioavailable and those that are inert and unavailable. For example, Pseudomonas fluorescens has been genetically engineered to be capable of degrading salicylate and naphthalene, and is used as a biosensor to assess the bioavailability of salicylate and naphthalene. Biosensors can also be used as an indicator of cellular metabolic activity and to detect the presence of pathogens. | 1 | Bioluminescence |
The type III granules are characterized by the fact that they contain several tubules with thick walls. The ferritin present in the granules is associated with filament-like features contained in them. | 1 | Bioluminescence |
To improve its biophysical properties, derivatives of coelenterazine have been synthesized by means of different procedures including multicomponent strategies. | 1 | Bioluminescence |
The most common classes of compounds with this property are the stilbenes, e.g., 4,4′-diamino-2,2′-stilbenedisulfonic acid. Older, non-commercial fluorescent compounds include umbelliferone, which absorbs in the UV portion of the spectrum and re-emit it in the blue portion of the visible spectrum. A white surface treated with an optical brightener can emit more visible light than that which shines on it, making it appear brighter. The blue light emitted by the brightener compensates for the diminishing blue of the treated material and changes the hue away from yellow or brown and toward white.
Approximately 400 brightener types are listed in the international Colour Index database, but fewer than 90 are produced commercially, and only a handful are commercially important. The Colour Index Generic Names and Constitution Numbers can be assigned to a specific substance. However, some are duplicated, since manufacturers apply for the index number when they produce it. The global OBA production for paper, textiles, and detergents is dominated by just a few di- and tetra-sulfonated triazole-stilbenes and a di-sulfonated stilbene-biphenyl derivatives. The stilbene derivatives are subject to fading upon prolonged exposure to UV, due to the formation of optically inactive cis-stilbenes. They are also degraded by oxygen in air, like most dye colorants. All brighteners have extended conjugation and/or aromaticity, allowing for electron movement. Some non-stilbene brighteners are used in more permanent applications such as whitening synthetic fiber.
Brighteners can be "boosted" by the addition of certain polyols, such as high molecular weight polyethylene glycol or polyvinyl alcohol. These additives increase the visible blue light emissions significantly. Brighteners can also be "quenched". Excess brightener will often cause a greening effect as emissions start to show above the blue region in the visible spectrum. | 0 | Luminescence |
From around 2002 to 2012, chemical brighteners were used by many Chinese farmers to enhance the appearance of their white mushrooms. This illegal use was mostly eliminated by the Chinese Ministry of Agriculture. | 0 | Luminescence |
The Sylvania Lighting Division in Salem and Danvers, Massachusetts, produced and marketed an EL night light, under the trade name Panelescent at roughly the same time that the Chrysler instrument panels entered production. These lamps have proven extremely reliable, with some samples known to be still functional after nearly 50 years of continuous operation.
Later in the 1960s, Sylvania's Electronic Systems Division in Needham, Massachusetts developed and manufactured several instruments for the Apollo Lunar Module and Command Module using electroluminescent display panels manufactured by the Electronic Tube Division of Sylvania at Emporium, Pennsylvania. Raytheon in Sudbury, Massachusetts manufactured the Apollo Guidance Computer, which used a Sylvania electroluminescent display panel as part of its display-keyboard interface (DSKY). | 0 | Luminescence |
Vargulin, also called Cypridinid luciferin, Cypridina luciferin, or Vargula luciferin, is the luciferin found in the ostracod Cypridina hilgendorfii, also named Vargula hilgendorfii. These bottom dwelling ostracods emit a light stream into water when disturbed presumably to deter predation. Vargulin is also used by the midshipman fish, Porichthys. | 1 | Bioluminescence |
GFP can be used to analyse the colocalization of proteins. This is achieved by "splitting" the protein into two fragments which are able to self-assemble, and then fusing each of these to the two proteins of interest. Alone, these incomplete GFP fragments are unable to fluoresce. However, if the two proteins of interest colocalize, then the two GFP fragments assemble together to form a GFP-like structure which is able to fluoresce. Therefore, by measuring the level of fluorescence it is possible to determine whether the two proteins of interest colocalize. | 1 | Bioluminescence |
Phylogenetic analyses performed by Zhang et al. (2020) suggest that the luciferses of the Lampyridae, Rhagopthalmidae, and Phenogodidae families diverged from the Elateridae family 205 Mya. According to phylogenetic data, the emergences of these two luciferases appeared even before the families could diverge– indicating their analogous nature due phenotypic convergences. | 1 | Bioluminescence |
Bioluminescence is the process of light emission in living organisms. Bioluminescence imaging utilizes native light emission from one of several organisms which bioluminesce, also known as luciferase enzymes. The three main sources are the North American firefly, the sea pansy (and related marine organisms), and bacteria like Photorhabdus luminescens and Vibrio fischeri. The DNA encoding the luminescent protein is incorporated into the laboratory animal either via a viral vector or by creating a transgenic animal. Rodent models of cancer spread can be studied through bioluminescence imaging.for e.g.Mouse models of breast cancer metastasis.
Systems derived from the three groups above differ in key ways:
* Firefly luciferase requires D-luciferin to be injected into the subject prior to imaging. The peak emission wavelength is about 560 nm. Due to the attenuation of blue-green light in tissues, the red-shift (compared to the other systems) of this emission makes detection of firefly luciferase much more sensitive in vivo.
* Renilla luciferase (from the Sea pansy) requires its substrate, coelenterazine, to be injected as well. As opposed to luciferin, coelenterazine has a lower bioavailability (likely due to MDR1 transporting it out of mammalian cells). Additionally, the peak emission wavelength is about 480 nm.
* Bacterial luciferase has an advantage in that the lux operon used to express it also encodes the enzymes required for substrate biosynthesis. Although originally believed to be functional only in prokaryotic organisms, where it is widely used for developing bioluminescent pathogens, it has been genetically engineered to work in mammalian expression systems as well. This luciferase reaction has a peak wavelength of about 490 nm.
While the total amount of light emitted from bioluminescence is typically small and not detected by the human eye, an ultra-sensitive CCD camera can image bioluminescence from an external vantage point. | 1 | Bioluminescence |
According to legend, Puerto Mosquito is named after the Mosquito, the name of one of pirate Roberto Cofresí's ships. The bio bay was proclaimed a National Natural Landmark in 1980. | 1 | Bioluminescence |
EL works by exciting atoms by passing an electric current through them, causing them to emit photons. By varying the material being excited, the colour of the light emitted can be changed. The actual ELD is constructed using flat, opaque electrode strips running parallel to each other, covered by a layer of electroluminescent material, followed by another layer of electrodes, running perpendicular to the bottom layer. This top layer must be transparent in order to let light escape. At each intersection, the material lights, creating a pixel. | 0 | Luminescence |
Thick-film dielectric electroluminescent technology (TDEL) is a phosphor-based flat panel display technology developed by Canadian company iFire Technology Corp. TDEL is based on inorganic electroluminescent (IEL) technology that combines both thick-and thin-film processes. The TDEL structure is made with glass or other substrates, consisting of a thick-film dielectric layer and a thin-film phosphor layer sandwiched between two sets of electrodes to create a matrix of pixels. Inorganic phosphors within this matrix emit light in the presence of an alternating electric field. | 0 | Luminescence |
Biosynthesis of coelenterazine in Metridia starts from two molecules of tyrosine and one molecule of phenylalanine, and some researchers believe this comes in the form of a cyclized "Phe-Tyr-Tyr" (FYY) peptide.
Many members of the genus Metridia also produce luciferases that use this compound, some of which are secreted into extracellular space, an unusual property for luciferases. | 1 | Bioluminescence |
Radium was discovered by Marie and Pierre Curie in 1898 and was soon combined with paint to make luminescent paint, which was applied to clocks, airplane instruments, and the like, to be able to read them in the dark.
In 1914, Dr. Sabin Arnold von Sochocky and Dr. George S. Willis founded the Radium Luminous Material Corporation. The company made luminescent paint. The company later changed its name to the United States Radium Corporation. The use of radium to provide luminescence for hands and indices on watches soon followed.
The Ingersoll Watch division of the Waterbury Clock Company, a nationally-known maker of low-cost pocket and wristwatches, was a leading popularizer of the use of radium for watch hands and indices through the introduction of their "Radiolite" watches in 1916. The Radiolite series, made in various sizes and models, became a signature of the Connecticut-based company.
Radium dials were typically painted by young women, who used to point their brushes by licking and shaping the bristles prior to painting the fine lines and numbers on the dials. This practice resulted in the ingestion of radium, which caused serious jaw-bone degeneration and malignancy and other dental diseases. The disease, radium-induced osteonecrosis, was recognized as an occupational disease in 1925 after a group of radium painters, known as the Radium Girls, from the United States Radium Corporation sued. By 1930, all dial painters stopped pointing their brushes by mouth. Stopping this practice drastically reduced the amount of radium ingested and therefore, the incidence of malignancy.
Luminous Processes employees interviewed by a journalist in 1978 stated they had been left ignorant of radium's dangers. They were told that eliminating lip-pointing had ended earlier problems. They worked in unvented rooms, they wore smocks that they laundered at home. Geiger counters could pick up readings from pants returned from a dry cleaner and from clothes stored away in a cedar chest." | 0 | Luminescence |
Coelenterazine can be crystallized into orange-yellow crystals. The molecule absorbs light in the ultraviolet and visible spectrum, with peak absorption at 435 nm in methanol, giving the molecule a yellow color. The molecule spontaneously oxidizes in aerobic conditions or in some organic solvents such as dimethylformamide and DMSO and is preferentially stored in methanol or with an inert gas. | 1 | Bioluminescence |
A photocyte is a cell that specializes in catalyzing enzymes to produce light (bioluminescence). Photocytes typically occur in select layers of epithelial tissue, functioning singly or in a group, or as part of a larger apparatus (a photophore). They contain special structures termed as photocyte granules. These specialized cells are found in a range of multicellular animals including ctenophora, coelenterates (cnidaria), annelids, arthropoda (including insects) and fishes. Although some fungi are bioluminescent, they do not have such specialized cells. | 1 | Bioluminescence |
An autoluminograph is a photograph produced by placing a light emitting object directly on a piece of film. A famous example is an autoluminograph published in Science magazine in 1986 of a glowing transgenic tobacco plant bearing the luciferase gene of fireflies placed on Kodak Ektachrome 200 film. | 1 | Bioluminescence |
Many PAFPs have been engineered from existing fluorescent proteins or identified from large-scale screens in the wake of Kaede's discovery. Many of these undergo green-to-red photoconversion, but other colors are available. Some proteins take part in irreversible photoconversion reactions while other reactions can be reversed using light of a specific wavelength. | 1 | Bioluminescence |
Unlike other fluorescent proteins, PAFPs can be used as selective optical markers. An entirely labeled cell can be followed to assess cell division, migration, and morphology. Very small volumes containing PAFPs can be activated with a laser. In these cases, protein trafficking, diffusion, and turnover can be assessed. | 1 | Bioluminescence |
EosFP is a photoactivatable green to red fluorescent protein. Its green fluorescence (516 nm) switches to red (581 nm) upon UV irradiation of ~390 nm (violet/blue light) due to a photo-induced modification resulting from a break in the peptide backbone near the chromophore. Eos was first discovered as a tetrameric protein in the stony coral Lobophyllia hemprichii. Like other fluorescent proteins, Eos allows for applications such as the tracking of fusion proteins, multicolour labelling and tracking of cell movement. Several variants of Eos have been engineered for use in specific study systems including mEos2, mEos4 and CaMPARI. | 1 | Bioluminescence |
As all other fluorescent proteins, Kaede can be the regional optical markers for gene expression and protein labeling for the study of cell behaviors.
One of the most useful applications is the visualization of neurons. Delineation of an individual neuron is difficult due to the long and thin processes which entangle with other neurons. Even when cultured neurons are labeled with fluorescent proteins, they are still difficult to identify individually because of the dense package.
In the past, such visualization could be done conventionally by filling neurons with Lucifer yellow or sulforhodamine, which is a laborious technique.[1] After the discovery of Kaede protein, it was found to be useful in delineating individual neurons. The neurons are transfected by Kaede protein cDNA, and are UV irradiated. The red, photoconverted Kaede protein has free diffusibility in the cell except for the nucleus, and spreads over the entire cell including dendrites and axon. This technique help disentangle the complex networks established in a dense culture. Besides, by labeling neurons with different colors by UV irradiating with different duration times, contact sites between the red and green neurons of interest are allowed to be visualized.
The ability of visualization of individual cells is also a powerful tool to identify the precise morphology and migratory behaviors of individual cells within living cortical slices. By Kaede protein, a particular pair of daughter cells in neighboring Kaede-positive cells in the ventricular zone of mouse brain slices can be followed. The cell-cell borders of daughter cells are visualized and the position and distance between two or more cells can be described.
As the change in the fluorescent colour is induced by UV light, marking of cells and subcellular structures is efficient even when only a partial photoconversion is induced. | 1 | Bioluminescence |
EosFP has been used to track cell movements during embryonic development of Xenopus laevis. At the two-cell/ early gastrula stage, capped mRNA coding for a dimeric EosFP (d2EosFP) was injected into cells and locally photoconverted using fluorescence microscopy. These fluorescent embryos demonstrated the dynamics of cell movement during neurulation. EosFP was found in part of the notochord which shows the possibility of EosFP to be used in fate-mapping experiments. | 1 | Bioluminescence |
ZnS exists in two main crystalline forms. This dualism is an example of polymorphism. In each form, the coordination geometry at Zn and S is tetrahedral. The more stable cubic form is known also as zinc blende or sphalerite. The hexagonal form is known as the mineral wurtzite, although it also can be produced synthetically. The transition from the sphalerite form to the wurtzite form occurs at around 1020 °C. | 0 | Luminescence |
The effect that different chemicals present in solution have to the velocity of the collapsing bubble has recently been studied. Nonvolatile liquids such as sulfuric and phosphoric acid have been shown to produce flashes of light several nanoseconds in duration with a much slower bubble wall velocity, and producing several thousand-fold greater light emission. This effect is probably masked in SBSL in aqueous solutions by the absorption of light by water molecules and contaminants. | 0 | Luminescence |
In the 1960s and 1970s, GFP, along with the separate luminescent protein aequorin (an enzyme that catalyzes the breakdown of luciferin, releasing light), was first purified from the jellyfish Aequorea victoria and its properties studied by Osamu Shimomura. In A. victoria, GFP fluorescence occurs when aequorin interacts with Ca ions, inducing a blue glow. Some of this luminescent energy is transferred to the GFP, shifting the overall color towards green. However, its utility as a tool for molecular biologists did not begin to be realized until 1992 when Douglas Prasher reported the cloning and nucleotide sequence of wtGFP in Gene. The funding for this project had run out, so Prasher sent cDNA samples to several labs. The lab of Martin Chalfie expressed the coding sequence of wtGFP, with the first few amino acids deleted, in heterologous cells of E. coli and C. elegans, publishing the results in Science in 1994. Frederick Tsuji's lab independently reported the expression of the recombinant protein one month later. Remarkably, the GFP molecule folded and was fluorescent at room temperature, without the need for exogenous cofactors specific to the jellyfish. Although this near-wtGFP was fluorescent, it had several drawbacks, including dual peaked excitation spectra, pH sensitivity, chloride sensitivity, poor fluorescence quantum yield, poor photostability and poor folding at .
The first reported crystal structure of a GFP was that of the S65T mutant by the Remington group in Science in 1996. One month later, the Phillips group independently reported the wild-type GFP structure in Nature Biotechnology. These crystal structures provided vital background on chromophore formation and neighboring residue interactions. Researchers have modified these residues by directed and random mutagenesis to produce the wide variety of GFP derivatives in use today. Further research into GFP has shown that it is resistant to detergents, proteases, guanidinium chloride (GdmCl) treatments, and drastic temperature changes. | 1 | Bioluminescence |
The symbiotic relationship between the Hawaiian bobtail squid Euprymna scolopes and the marine gram-negative bacterium Aliivibrio fischeri has been well studied. The two organisms exhibit a mutualistic relationship in which bioluminescence produced by A. fischeri helps to attract pray to the squid host, which provides nutrient-rich tissues and a protected environment forA. fischeri. Bioluminescence provided by A. fischeri also aids in the defense of the squid E. scolopes by providing camouflage during its nighttime foraging activity. Following bacterial colonization, the specialized organs of the squid undergo developmental changes and a relationship becomes established. The squid expels 90% of the bacterial population each morning, because it no longer needs to produce bioluminescence in the daylight. This expulsion benefits the bacteria by aiding in their dissemination. A single expulsion by one bobtail squid produces enough bacterial symbionts to fill 10,000m of seawater at a concentration that is comparable to what is found in coastal waters. Thus, in at least some habitats, the symbiotic relationship between A. fischeri and E. scolopes plays a key role in determining the abundance and distribution of E. scolopes. There is a higher abundance of A. fischeri in the vicinity of a population of E. scolopes and this abundance markedly decreases with increasing distance from the host's habitat.
Bioluminescent Photobacterium species also engage in mutually beneficial associations with fish and squid. Dense populations of P. kishitanii, P. leiogathi, and P. mandapamensis can live in the light organs of marine fish and squid, and are provided with nutrients and oxygen for reproduction in return for providing bioluminescence to their hosts, which can aid in sex-specific signaling, predator avoidance, locating or attracting prey, and schooling.<!-- Empty reference | 1 | Bioluminescence |
Incandescence is the emission of electromagnetic radiation (including visible light) from a hot body as a result of its high temperature. The term derives from the Latin verb incandescere, to glow white. A common use of incandescence is the incandescent light bulb, now being phased out.
Incandescence is due to thermal radiation. It usually refers specifically to visible light, while thermal radiation refers also to infrared or any other electromagnetic radiation. | 0 | Luminescence |
Goldstein used a gas-discharge tube which had a perforated cathode. When an electrical potential of several thousand volts is applied between the cathode and anode, faint luminous "rays" are seen extending from the holes in the back of the cathode. These rays are beams of particles moving in a direction opposite to the "cathode rays", which are streams of electrons which move toward the anode. Goldstein called these positive rays Kanalstrahlen, "channel rays", or "canal rays", because these rays passed through the holes or channels in the cathode.
The process by which anode rays are formed in a gas-discharge anode ray tube is as follows. When the high voltage is applied to the tube, its electric field accelerates the small number of ions (electrically charged atoms) always present in the gas, created by natural processes such as radioactivity. These collide with atoms of the gas, knocking electrons off them and creating more positive ions. These ions and electrons in turn strike more atoms, creating more positive ions in a chain reaction. The positive ions are all attracted to the negative cathode, and some pass through the holes in the cathode. These are the anode rays.
By the time they reach the cathode, the ions have been accelerated to a sufficient speed such that when they collide with other atoms or molecules in the gas they excite the species to a higher energy level. In returning to their former energy levels these atoms or molecules release the energy that they had gained. That energy gets emitted as light. This light-producing process, called fluorescence, causes a glow in the region behind the cathode. | 0 | Luminescence |
In its anionic form, the green chromophore has an absorption maxima at 506 nm and an emission maxima at 516 nm. It is formed autocatalytically from amino acids His-62, Tyr-63 and Gly-64. Immediately surrounding the chromophore there is a cluster of charged or polar amino acids as well as structural water molecules. Above the plane of the chromophore, there is a network of hydrogen bond interactions between Glu-144, His-194, Glu-212 and Gln-38. Arg-66 and Arg-91 participate in hydrogen bonding with the carbonyl oxygen of green Eos's imidazolinone moiety. The His-62 side chain lies in an unpolar environment. Conversion from the green to red form depends on the presence of a histidine in the first position of the tripeptide HYG that forms the chromophore. When this histidine residue is substituted with M, S, T or L, Eos only emits bright green light and no longer acts as a photoconvertible fluorescent protein. | 1 | Bioluminescence |
Between 1915 and 1993, 235 sightings of milky seas were documented, most of which are concentrated in the northwestern Indian Ocean near to Somalia. The luminescent glow is concentrated on the surface of the ocean and does not mix evenly throughout the water column.
In 1985, a research vessel in the Arabian Sea took water samples during milky seas. Their conclusions were that the effect was caused by the bacterium Vibrio harveyi. Mareel is typically caused by Noctiluca scintillans (popularly known as "sea sparkle"), a dinoflagellate that glows when disturbed and is found in oceans throughout much of the world.
In July 2015, at Alleppey, Kerala, India, the phenomenon occurred and the National Institute of Oceanography and Kerala Fisheries Department researched it, finding that the glittering waves were the result of Noctiluca scintillans.
In 2005, Steven Miller of the Naval Research Laboratory in Monterey, California, was able to match 1995 satellite images with a first-hand account of a merchant ship. U.S. Defense Meteorological Satellite Program showed the milky area to be approximately (roughly the size of Connecticut). The luminescent field was observed to glow over three consecutive nights.
While monochromatic photos make this effect appear white, Monterey Bay Aquarium Research Institute scientist Steven Haddock (an author of a milky seas effect study) has commented, "the light produced by the bacteria is actually blue, not white. It is white in the graphic because of the monochromatic sensor we used, and it can appear white to the eye because the rods in our eye (used for night vision) dont discriminate color." In Shetland (where generally caused by Noctiluca scintillans'), mareel has sometimes been described as being green, rather than the traditional blue or white milky seas effect seen by the rest of the world. It is not known whether this difference depends on the area, or simply a perception of a cyanic colour as being green. | 1 | Bioluminescence |
Phosphor banded stamps first appeared in 1959 as guides for machines to sort mail. Around the world many varieties exist with different amounts of banding. Postage stamps are sometimes collected by whether or not they are "tagged" with phosphor (or printed on luminescent paper). | 0 | Luminescence |
The Akula is a Dunkleosteus like creature. They have 3 sets of jaws and is the apex predator of the Pandoran ocean. They are introduced in Avatar: The Way of Water, where Jakes son Loak fights of one after he is stranded in the ocean, before being saved by Payakan. | 1 | Bioluminescence |
In geology, mineralogy, materials science and semiconductor engineering, a scanning electron microscope (SEM) fitted with a cathodoluminescence detector, or an optical cathodoluminescence microscope, may be used to examine internal structures of semiconductors, rocks, ceramics, glass, etc. in order to get information on the composition, growth and quality of the material. | 0 | Luminescence |
The main advantage of FbFPs over GFP is their independence of molecular oxygen. Since all GFP derivatives and homologues require molecular oxygen for the maturation of their chromophore, these fluorescent proteins are of limited use under anaerobic or hypoxic conditions.
Since FbFPs bind FMN as chromophore, which is synthesized independently of molecular oxygen, their fluorescence signal does not differ between aerobic and anaerobic conditions.<br />
Another advantage is the small size of FbFPs, which is typically between 100 and 150 amino acids. This is about half the size of GFP (238 amino acids). It could for example be shown that this renders them superior tags for monitoring tobacco mosaic virus infections in tobacco leaves.<br />
Due to their extraordinary long average fluorescence lifetime of up to 5.7 ns they are also very well suited for the use as donor domains in FRET systems in conjunction with e.g. YFP (see photophysical properties). A fusion of EcFbFP and YFP was e.g. used to develop the first genetically encoded fluorescence biosensor for oxygen (FluBO)
The main disadvantage compared to GFP variants is their lower brightness (the product of ε and Φ). The commonly used EGFP (ε = 55,000 Mcm; Φ = 0.60 ) for example is approximately five times as bright as EcFbFP.<br />
Another disadvantage of the FbFPs is the lack of color variants to tag and distinguish multiple proteins in a single cell or tissue. The largest spectral shift reported for FbFPs so far is 10 nm. Although this variant (Pp2FbFP Q116V) can be visually distinguished from the others with the human eye, the spectral differences are too small for fluorescence microscopy filters. | 1 | Bioluminescence |
Strontium aluminates are considered non-toxic, and are biologically and chemically inert.
Care should be used when handling loose powder, which can cause irritation if inhaled or exposed to mucous membranes. | 0 | Luminescence |
Julian Voss-Andreae, a German-born artist specializing in "protein sculptures," created sculptures based on the structure of GFP, including the 1.70 m (56") tall "Green Fluorescent Protein" (2004) and the 1.40 m (47") tall "Steel Jellyfish" (2006). The latter sculpture is located at the place of GFPs discovery by Shimomura in 1962, the University of Washingtons Friday Harbor Laboratories. | 1 | Bioluminescence |
The thanator (Palulukan in Navi) is a large hexapodal land predator that is believed, by the RDA, to be the apex land predator. It is scientifically known as Bestiapanthera ferox. Cameron personally designed the creature. The thanator is first seen when Jake wanders off into the jungle and touches multiple helicoradian leaves, at which they retract to reveal a family of hammerhead titanotheres behind. The thanator frightens the titanotheres and pursues Jake. Jake later escapes the thanator by jumping off a cliff into pool below. It later appears during the climax where it assists Neytiri and later battles Quaritchs AMP Suit Beyond Glory, but is killed by the AMP suit's knife. The thanator is black with white fleshy skin under each hand. Its appearance is similar to a panther; Cameron describes the thanator as "the panther from hell". The thanator has ten sensory quills connected to six pads at the rear of the skull that flare up before it attacks the prey. The director explained how the thanator is the most fearsome creature on Pandora, "The thanator could eat a T-Rex and have the Alien for dessert." | 1 | Bioluminescence |
Overall, the evolution of light producing cells (photocytes) is believed to have happened twice in sharks through convergence. Evidence suggests that the bioluminescent properties of the shark, Etmopterus spinax, came about as a mechanism of camouflage. It is thought that luminescence has other functions as well due to camouflage not being a logical explanation for the luminescence on the lateral sides of the shark. Bioluminescence is believed to have only evolved in sharks among the cartilaginous fishes. The function of bioluminescence among sharks has not been fully ascertained. | 1 | Bioluminescence |
Both sphalerite and wurtzite are intrinsic, wide-bandgap semiconductors. These are prototypical II-VI semiconductors, and they adopt structures related to many of the other semiconductors, such as gallium arsenide. The cubic form of ZnS has a band gap of about 3.54 electron volts at 300 kelvins, but the hexagonal form has a band gap of about 3.91 electron volts. ZnS can be doped as either an n-type semiconductor or a p-type semiconductor. | 0 | Luminescence |
Apoaequorin is an ingredient in "Prevagen", which is marketed by Quincy Bioscience as a memory supplement. In 2017, the US Federal Trade Commission (FTC) charged the maker with falsely advertising that the product improves memory, provides cognitive benefits, and is "clinically shown" to work. According to the FTC, "the marketers of Prevagen preyed on the fears of older consumers experiencing age-related memory loss". Quincy said that it would fight the charges.
Prior to the suit, a clinical trial run by researchers employed by Quincy Bioscience "found no overall benefit compared to a placebo for its primary endpoints involving memory and cognition", while the company's advertising misleadingly cited a few contested subgroup analyses that showed slight improvements.
The suit (Spath, et al. v. Quincy Bioscience Holding Company, Inc., et al., Case No. 18-cv-12416, D. NJ.) was dismissed in the District court, but an appeal seeking to overturn the dismissal was filed. The suit was consolidated with another against Quincy Pharmaceuticals, Vanderwerff v. Quincy Bioscience (Case No. 17-cv-784, D. NJ), which was the lead case.
On February 21, 2019, the United States Court of Appeals for the Second Circuit ruled that the FTC and the state of New York could proceed with their lawsuit against Quincy Bioscience for its claims that Prevagen can improve memory. The order came less than two weeks after the parties argued the case before a three-judge panel of the circuit, where company lawyers admitted they did not "dispute that if you look across the entire 211 people who completed the study there was no statistically significant difference". The court vigorously dismissed allegations by the company lawyers that the FTC pursued its action for political reasons.
On March 23, 2020, a federal magistrate judge in the United States District Court for the Southern District of Florida entered a report and recommendations certifying a nationwide class action for the class of consumers who purchased Prevagen over the previous four years. The trial in the case was set for October 2020.
Quincy Bioscience agreed to settle the claims that it misrepresented its Prevagen products as supporting brain health and helping with memory loss. Under the terms of the settlement, eligible purchasers applying by October 26, 2020 for purchases made from 2007 through July 31, 2020 could recover refunds of up to $70.
Dr. Harriet Hall, writing for Science-Based Medicine, noted that the Quincy-sponsored study (known as "Madison Memory Study") was negative, but that the company utilized p-hacking to find favorable results. She wrote that their cited safety studies were all rat studies and their claim that apoaequorin crosses the blood–brain barrier was based solely on a dog study. The American Pharmacists Association warns that Apoaequorin "is unlikely to be absorbed to a significant degree; instead it degrades into amino acids". | 1 | Bioluminescence |
Light production may first be triggered by nerve impulses which stimulate the photocyte to release the enzyme luciferase into a "reaction chamber" of luciferin substrate. In some species the release occurs continually without the precursor impulse via osmotic diffusion. Molecular oxygen is then actively gated through surrounding tracheal cells which otherwise limit the natural diffusion of oxygen from blood vessels; the resulting reaction with the luciferase and luciferin produces light energy and a by-product (usually carbon dioxide). The reaction occurs in the peroxisome of the cell.
Researchers once postulated that ATP was the source of reaction energy for photocytes, but since ATP only produces a fraction the energy of the luciferase reaction, any resulting light wave-energy would be too small for detection by a human eye. The wavelengths produced by most photocytes fall close to 490 nm; although light as energetic as 250 nm is reportedly possible.
The variations of color seen in different photocytes are usually the result of color filters that alter the wavelength of the light prior to exiting the endoderm, thanks to the other parts of the photophore. The range of colors vary between bioluminescent species.
The exact combinations of luciferase and luciferin types found among photocytes are specific to the species to which they belong. This would seem to be the result of consistent evolutionary divergence. | 1 | Bioluminescence |
Work on aequorin began with E. Newton Harvey in 1921. Though Harvey was unable to demonstrate a classical luciferase-luciferin reaction, he showed that water could produce light from dried photocytes and that light could be produced even in the absence of oxygen. Later, Osamu Shimomura began work into the bioluminescence of Aequorea in 1961. This involved tedious harvesting of tens of thousands of jellyfish from the docks in Friday Harbor, Washington. It was determined that light could be produced from extracts with seawater, and more specifically, with calcium. It was also noted during the extraction the animal creates green light due to the presence of the green fluorescent protein, which changes the native blue light of aequorin to green.
While the main focus of his work was on the bioluminescence, Shimomura and two others, Martin Chalfie and Roger Tsien, were awarded the Nobel Prize in 2008 for their work on green fluorescent proteins. | 1 | Bioluminescence |
By arranging each strand of EL wire into a shape slightly different from the previous one, it is possible to create animations using EL wire sequencers. EL wire sequencers are also used for costumes and have been used to create animations on various items such as kimono, purses, neckties, and motorcycle tanks. They are increasingly popular among artists, dancers, maker culture, and similar creative communities, such as exhibited in the annual Burning Man alt-culture festival. | 0 | Luminescence |
A cathodoluminescence (CL) microscope combines a regular (light optical) microscope with a cathode-ray tube. It is designed to image the luminescence characteristics of polished thin sections of solids irradiated by an electron beam.
Using a cathodoluminescence microscope, structures within crystals or fabrics can be made visible which cannot be seen in normal light conditions. Thus, for example, valuable information on the growth of minerals can be obtained. CL-microscopy is used in geology, mineralogy and materials science for the investigation of rocks, minerals, volcanic ash, glass, ceramic, concrete, fly ash, etc.
CL color and intensity are dependent on the characteristics of the sample and on the working conditions of the electron gun. Here, acceleration voltage and beam current of the electron beam are of major importance. Today, two types of CL microscopes are in use. One is working with a "cold cathode" generating an electron beam by a corona discharge tube, the other one produces a beam using a "hot cathode". Cold-cathode CL microscopes are the simplest and most economical type. Unlike other electron bombardment techniques like electron microscopy, cold cathodoluminescence microscopy provides positive ions along with the electrons which neutralize surface charge buildup and eliminate the need for conductive coatings to be applied to the specimens. The "hot cathode" type generates an electron beam by an electron gun with tungsten filament. The advantage of a hot cathode is the precisely controllable high beam intensity allowing to stimulate the emission of light even on weakly luminescing materials (e.g. quartz – see picture). To prevent charging of the sample, the surface must be coated with a conductive layer of gold or carbon. This is usually done by a sputter deposition device or a carbon coater. | 0 | Luminescence |
The protein structure of firefly luciferase consists of two compact domains: the N-terminal domain and the C-terminal domain. The N-terminal domain is composed of two β-sheets in an αβαβα structure and a β barrel. The two β-sheets stack on top of each other, with the β-barrel covering the end of the sheets.
The C-terminal domain is connected to the N-terminal domain by a flexible hinge, which can separate the two domains. The amino acid sequences on the surface of the two domains facing each other are conserved in bacterial and firefly luciferase, thereby strongly suggesting that the active site is located in the cleft between the domains.
During a reaction, luciferase has a conformational change and goes into a "closed" form with the two domains coming together to enclose the substrate. This ensures that water is excluded from the reaction and does not hydrolyze ATP or the electronically excited product. | 1 | Bioluminescence |
Phosphorescent materials were discovered in the 1700s, and people have been studying them and making improvements over the centuries. The development of strontium aluminate pigments in 1993 was spurred on by the need to find a substitute for glow-in-the-dark materials with high luminance and long phosphorescence, especially those that used promethium. This led to the discovery by Yasumitsu Aoki (Nemoto & Co.) of materials with luminance approximately 10 times greater than zinc sulfide and phosphorescence approximately 10 times longer, and 10 times more expensive. The invention was patented by Nemoto & Co., Ltd. and licensed to other manufacturers and watch brands. Strontium aluminates are now the longest lasting and brightest phosphorescent material commercially available.
For many phosphorescence-based purposes, strontium aluminate is a superior phosphor to its predecessor, copper-activated zinc sulfide, being about 10 times brighter and 10 times longer glowing. It is frequently used in glow in the dark objects, where it replaces the cheaper but less efficient Cu:ZnS that many people recognize with nostalgia – this is what made glow in the dark stars stickers glow.
Advancements in understanding of phosphorescent mechanisms, as well as advancements in molecular imaging, have enabled the development of novel, state-of-the-art strontium aluminates. | 0 | Luminescence |
*9,10-Diphenylanthracene (DPA) emits blue light
*9-(2-Phenylethenyl) anthracene emits teal light
*1-Chloro-9,10-diphenylanthracene (1-chloro(DPA)) and 2-chloro-9,10-diphenylanthracene (2-chloro(DPA)) emit blue-green light more efficiently than nonsubstituted DPA
*9,10-Bis(phenylethynyl)anthracene (BPEA) emits green light with maximum at 486 nm
*1-Chloro-9,10-bis(phenylethynyl)anthracene emits yellow-green light, used in 30-minute high-intensity Cyalume sticks
*2-Chloro-9,10-bis(phenylethynyl)anthracene emits green light, used in 12-hour low-intensity Cyalume sticks
*1,8-Dichloro-9,10-bis(phenylethynyl)anthracene emits yellow light, used in Cyalume sticks
*Rubrene emits orange-yellow at 550 nm
*2,4-Di-tert-butylphenyl 1,4,5,8-tetracarboxynaphthalene diamide emits deep red light, together with DPA is used to produce white or hot-pink light, depending on their ratio
*Rhodamine B emits red light. It is rarely used, as it breaks down in contact with CPPO, shortening the shelf life of the mixture.
*5,12-Bis(phenylethynyl)naphthacene emits orange light
*Violanthrone emits orange light at 630 nm
*16,17-(1,2-Ethylenedioxy)violanthrone emits red at 680 nm
*16,17-Dihexyloxyviolanthrone emits infrared at 725 nm
*16,17-Butyloxyviolanthrone emits infrared
*N,N′-Bis(2,5,-di-tert-butylphenyl)-3,4,9,10-perylenedicarboximide emits red
*1-(N,N-Dibutylamino)anthracene emits infrared
*6-Methylacridinium iodide emits infrared | 0 | Luminescence |
All bacterial species that have been reported to possess bioluminescence belong within the families Vibrionaceae, Shewanellaceae, or Enterobacteriaceae, all of which are assigned to the class Gammaproteobacteria.
(List from Dunlap and Henryk (2013), "Luminous Bacteria", The Prokaryotes ) | 1 | Bioluminescence |
GFP has a beta barrel structure consisting of eleven β-strands with a pleated sheet arrangement, with an alpha helix containing the covalently bonded chromophore 4-(p-hydroxybenzylidene)imidazolidin-5-one (HBI) running through the center. Five shorter alpha helices form caps on the ends of the structure. The beta barrel structure is a nearly perfect cylinder, 42Å long and 24Å in diameter (some studies have reported a diameter of 30Å), creating what is referred to as a "β-can" formation, which is unique to the GFP-like family. HBI, the spontaneously modified form of the tripeptide Ser65–Tyr66–Gly67, is nonfluorescent in the absence of the properly folded GFP scaffold and exists mainly in the un-ionized phenol form in wtGFP. Inward-facing sidechains of the barrel induce specific cyclization reactions in Ser65–Tyr66–Gly67 that induce ionization of HBI to the phenolate form and chromophore formation. This process of post-translational modification is referred to as maturation. The hydrogen-bonding network and electron-stacking interactions with these sidechains influence the color, intensity and photostability of GFP and its numerous derivatives. The tightly packed nature of the barrel excludes solvent molecules, protecting the chromophore fluorescence from quenching by water. In addition to the auto-cyclization of the Ser65-Tyr66-Gly67, a 1,2-dehydrogenation reaction occurs at the Tyr66 residue. Besides the three residues that form the chromophore, residues such as Gln94, Arg96, His148, Thr203, and Glu222 all act as stabilizers. The residues of Gln94, Arg96, and His148 are able to stabilize by delocalizing the chromophore charge. Arg96 is the most important stabilizing residue due to the fact that it prompts the necessary structural realignments that are necessary from the HBI ring to occur. Any mutation to the Arg96 residue would result in a decrease in the development rate of the chromophore because proper electrostatic and steric interactions would be lost. Tyr66 is the recipient of hydrogen bonds and does not ionize in order to produce favorable electrostatics. | 1 | Bioluminescence |
The first tagged stamps of Canada were issued in 1962 with vertical phosphorescent bands. In 1972, fluorescent general tagging was introduced, initially as vertical bars, now normally on all four sides of the stamp. | 0 | Luminescence |
The helicoradian (Loreyu in Navi) is a carnivorous plant that has red spiral-leaves. The plants are up to tall and, when touched, instantly curl and collapse into themselves. They are zooplantae, part animal, part plant. They are first seen when Jake wanders off into a forest of helicoradia and touches multiple leaves, at which they retract and coil up to reveal a hammerhead titanothere behind. According to Avatar designer Craig Shoji, the behavior and design of the helicoradian' was based on the Christmas tree worms, tube worms that reside on coral reefs. In the video games, the species has the ability to heal the player. | 1 | Bioluminescence |
SBSL emits more light than MBSL due to fewer interactions between neighboring bubbles. Another advantage for SBSL is that a single bubble collapses without being affected by other surrounding bubbles, allowing more accurate studies on acoustic cavitation and sonoluminescence theories. Some exotic theories have been made, for example from Schwinger in 1992 who hinted the dynamical Casimir effect as a potential photon-emission process. Several theories say that the location of light emission is in the liquid instead of inside the bubble. Other SBSL theories explain that the emission of photons due to the high temperatures in the bubble are analogical to the hot spot theories of MBSL. Regarding the thermal emission a large variety of different processes are prevalent. Because temperatures are increasing from several hundred to many thousand kelvin during collapse, the processes can be molecular recombination, collision-induced emission, molecular emission, excimers, atomic recombination, radiative attachments of ions, neutral and ion Bremsstrahlung, or emission from confined electrons in voids. Which of these theories applies depends on accurate measurements and calculations of the temperature inside the bubble. | 0 | Luminescence |
Bioluminescence has only been observed in three classes of mollusks: Cephalopoda, Gastropoda, and Bivalvia. Bioluminescence is widely spread among cephalopods, but much rarer among the other classes of mollusk. Most species of biolumenescent mollusk that have been discovered are found in the ocean with the exception of the genera Latia and Quantula found in freshwater and terrestrial habitats respectively; however, more recent research has discovered luminescence in the Phuphania genus. It is hypothesized that terrestrial mollusks that use bioluminescence developed it as a strategy to deter predation. The green color emanated by the mollusk's photocytes is thought to be the most visible color to nocturnal predators. | 1 | Bioluminescence |
All bacterial luciferases are approximately 80 KDa heterodimers containing two subunits: α and β. The α subunit is responsible for light emission. The luxA and luxB genes encode for the α and β subunits, respectively. In most bioluminescent bacteria, the luxA and luxB genes are flanked upstream by luxC and luxD and downstream by luxE.
The bioluminescent reaction is as follows:
FMNH + O + R-CHO -> FMN + HO + R-COOH + Light (~ 495 nm)
Molecular oxygen reacts with FMNH (reduced flavin mononucleotide) and a long-chain aldehyde to produce FMN (flavin mononucleotide), water and a corresponding fatty acid. The blue-green light emission of bioluminescence, such as that produced by Photobacterium phosphoreum and Vibro harveyi, results from this reaction. Because light emission involves expending six ATP molecules for each photon, it is an energetically expensive process. For this reason, light emission is not constitutively expressed in bioluminescent bacteria; it is expressed only when physiologically necessary. | 1 | Bioluminescence |
Marcel Joseph Vogel (April 14, 1917 – February 12, 1991) was a research scientist working at the IBM San Jose Research Center for 27 years. He is sometimes referred to as Dr. Vogel, although this title was based on an honorary degree, not a Ph.D. Later in his career, he became interested in various theories of quartz crystals and other occult and esoteric fields of study. | 0 | Luminescence |
Photoproteins do not display typical enzyme kinetics as seen in luciferases. Instead, when mixed with luciferin, they display luminescence proportional to the amount of the photoprotein. For example, the photoprotein aequorin produces a flash of light when luciferin and calcium are added, rather than the prolonged glow that is seen for luciferases when luciferin is added. In this respect, it may appear that photoproteins are not enzymes, when in fact they do catalyze their bioluminescence reactions. This is due to a fast catalytic step, which produces the light, and a slow regeneration step, where the oxyluciferin is freed and another molecule of luciferin is then enabled to bind to the enzyme. Because of the kinetically slow step, each aequorin molecule must "recharge" with another molecule of luciferin before it can emit light again, and this makes it appear as though it is not behaving as a typical enzyme.
Photoproteins form a stable luciferin-photoprotein complex, often until the addition of another required factor such as Ca in the case of aequorin. | 1 | Bioluminescence |
A formation light, also known as a slime light, is a type of thin film electroluminescent light that assists aircraft flying in formation in low visibility environments. | 0 | Luminescence |
The phosphorescence of ZnS was first reported by the French chemist Théodore Sidot in 1866. His findings were presented by A. E. Becquerel, who was renowned for the research on luminescence. ZnS was used by Ernest Rutherford and others in the early years of nuclear physics as a scintillation detector, because it emits light upon excitation by x-rays or electron beam, making it useful for X-ray screens and cathode ray tubes. This property made zinc sulfide useful in the dials of radium watches. | 0 | Luminescence |
Strontium aluminate is an aluminate compound with the chemical formula (sometimes written as ). It is a pale yellow, monoclinic crystalline powder that is odourless and non-flammable. When activated with a suitable dopant (e.g. europium, written as ), it acts as a photoluminescent phosphor with long persistence of phosphorescence.
Strontium aluminates exist in a variety of other compositions including (monoclinic), (cubic), (hexagonal), and (orthorhombic). The different compositions cause different colours of light to be emitted. | 0 | Luminescence |
Glow sticks are used by militaries, and occasionally also police tactical units, as light sources during night operations or close-quarters combat in dark areas. They are also used to mark secured areas or objects of note. When worn, they can be used to identify friendly soldiers during nighttime operations. | 0 | Luminescence |
A glow stick, also known as a light stick, chem light, light wand, light rod, and rave light, is a self-contained, short-term light-source. It consists of a translucent plastic tube containing isolated substances that, when combined, make light through chemiluminescence. The light cannot be turned off and can be used only once. The used tube is then thrown away. Glow sticks are often used for recreation, such as for events, camping, outdoor exploration, and concerts. Glow sticks are also used for light in military and emergency services applications. Industrial uses include marine, transportation, and mining. | 0 | Luminescence |
Luciferin () is a generic term for the light-emitting compound found in organisms that generate bioluminescence. Luciferins typically undergo an enzyme-catalyzed reaction with molecular oxygen. The resulting transformation, which usually involves breaking off a molecular fragment, produces an excited state intermediate that emits light upon decaying to its ground state. The term may refer to molecules that are substrates for both luciferases and photoproteins. | 1 | Bioluminescence |
Field-induced polymer electroluminescent (FIPEL) technology is a low power electroluminescent light source. Three layers of moldable light-emitting polymer blended with a small amount of carbon nanotubes glow when an alternating current is passed through them. The technology can produce white light similar to that of the Sun, or other tints if desired. It is also more efficient than compact fluorescent lamps in terms of the energy required to produce light. As cited from the Carroll Research Group at Wake Forest University, "To date our brightest device – without output couplers – exceeds 18,000 cd/m2." This confirms that FIPEL technology is a viable solution for area lighting.
FIPEL lights are different from LED lighting, in that there is no junction. Instead, the light emitting component is a layer of polymer containing an iridium compound which is doped with multi-wall carbon nanotubes. This planar light emitting structure is energized by an AC field from insulated electrodes. The lights can be shaped into many different forms, from mimicking conventional light bulbs to unusual forms such as 2-foot-by-4-foot flat sheets and straight or bent tubes. The technology was developed by a team headed by Dr. David Carroll of Wake Forest University in Winston-Salem, North Carolina. | 0 | Luminescence |
In chemistry, a luminophore (sometimes shortened to lumophore) is an atom or functional group in a chemical compound that is responsible for its luminescent properties. Luminophores can be either organic or inorganic.
Luminophores can be further classified as fluorophores or phosphors, depending on the nature of the excited state responsible for the emission of photons. However, some luminophores cannot be classified as being exclusively fluorophores or phosphors. Examples include transition-metal complexes such as tris(bipyridine)ruthenium(II) chloride, whose luminescence comes from an excited (nominally triplet) metal-to-ligand charge-transfer (MLCT) state, which is not a true triplet state in the strict sense of the definition; and colloidal quantum dots, whose emissive state does not have either a purely singlet or triplet spin.
Most luminophores consist of conjugated π systems or transition-metal complexes. There are also purely inorganic luminophores, such as zinc sulfide doped with rare-earth metal ions, rare-earth metal oxysulfides doped with other rare-earth metal ions, yttrium oxide doped with rare-earth metal ions, zinc orthosilicate doped with manganese ions, etc. Luminophores can be observed in action in fluorescent lights, television screens, computer monitor screens, organic light-emitting diodes and bioluminescence.
The correct, textbook terminology is luminophore, not lumophore, although the latter term has been frequently used in the chemical literature. | 0 | Luminescence |
Pistol shrimp (also called snapping shrimp) produce a type of cavitation luminescence from a collapsing bubble caused by quickly snapping its claw. The animal snaps a specialized claw shut to create a cavitation bubble that generates acoustic pressures of up to 80 kPa at a distance of 4 cm from the claw. As it extends out from the claw, the bubble reaches speeds of 60 miles per hour (97 km/h) and releases a sound reaching 218 decibels. The pressure is strong enough to kill small fish. The light produced is of lower intensity than the light produced by typical sonoluminescence and is not visible to the naked eye. The light and heat produced by the bubble may have no direct significance, as it is the shockwave produced by the rapidly collapsing bubble which these shrimp use to stun or kill prey. However, it is the first known instance of an animal producing light by this effect and was whimsically dubbed "shrimpoluminescence" upon its discovery in 2001. It has subsequently been discovered that another group of crustaceans, the mantis shrimp, contains species whose club-like forelimbs can strike so quickly and with such force as to induce sonoluminescent cavitation bubbles upon impact.
A mechanical device with 3D printed snapper claw at five times the actual size was also reported to emit light in a similar fashion, this bioinspired design was based on the snapping shrimp snapper claw molt shed from an Alpheus formosus, the striped snapping shrimp. | 0 | Luminescence |
Another important technique in testing samples from a historic or archaeological site is a process known as thermoluminescence testing, which involves the principle that all
objects absorb radiation from the environment. This process frees electrons within elements or minerals that remain caught within the item. Thermoluminescence testing involves
heating a sample until it releases a type of light, which is then measured to determine the last time the item was heated.
In thermoluminescence dating, these long-term traps are used to determine the age of materials: When irradiated crystalline material is again heated or exposed to strong light, the trapped electrons are given sufficient energy to escape. In the process of recombining with a lattice ion, they lose energy and emit photons (light quanta), detectable in the laboratory.
The amount of light produced is proportional to the number of trapped electrons that have been freed which is in turn proportional to the radiation dose accumulated. In order to relate the signal (the thermoluminescence—light produced when the material is heated) to the radiation dose that caused it, it is necessary to calibrate the material with known doses of radiation since the density of traps is highly variable.
Thermoluminescence dating presupposes a "zeroing" event in the history of the material, either heating (in the case of pottery or lava) or exposure to sunlight (in the case of sediments), that removes the pre-existing trapped electrons. Therefore, at that point the thermoluminescence signal is zero.
As time goes on, the ionizing radiation field around the material causes the trapped electrons to accumulate (Figure 2). In the laboratory, the accumulated radiation dose can be measured, but this by itself is insufficient to determine the time since the zeroing event.
The Radiation Dose Rate - the dose accumulated per year-must be determined first. This is commonly done by measurement of the alpha radioactivity (the uranium and thorium content) and the potassium content (K-40 is a beta and gamma emitter) of the sample material.
Often the gamma radiation field at the position of the sample material is measured, or it may be calculated from the alpha radioactivity and potassium content of the sample environment, and the cosmic ray dose is added in. Once all components of the radiation field are determined, the accumulated dose from the thermoluminescence measurements is divided by the dose accumulating each year, to obtain the years since the zeroing event. | 0 | Luminescence |
The Glowing Plant project was the first crowdfunding campaign for a synthetic biology application. The project was started by the Sunnyvale-based hackerspace Biocurious as part of the DIYbio philosophy. According to the projects goals, funds were used to create a glowing Arabidopsis thaliana' plant using firefly luminescence genes. Long-term ambitions (never realized) included the development of glowing trees that can be used to replace street lights, reducing CO emissions by not requiring electricity. | 1 | Bioluminescence |
The direhorse (Pali in Navi ) is a bioluminescent, hexapodal, superficially equine animal. It is scientifically known as Equidirus hoplites. The Navi use the direhorse to hunt. The direhorse was conceived and designed by Cameron and Stan Winston Studios. The direhorse is grey with blue stripes and stands tall, long. The Navi "break" a direhorse by connecting the fleshy tip of their hair to the animals antennae. Xenobiologists call this a neural whip. Once intertwined, the Navi rider can communicate motor commands instantly through the neural interface; however, this connection does not lead to a lifelong, exclusive bond, as it does with the mountain banshee. Cameron described the creature as a "six-legged alien Clydesdale with moth-like antennae". The direhorse uses its long tongue to eat the sap out of pitcher plants. | 1 | Bioluminescence |
Prosperetti found a way to accurately determine the internal pressure of the bubble using the following equation.
where is the temperature, is the thermal conductivity of the gas, and is the radial distance. | 0 | Luminescence |
The collapsed bubble expands due to high internal pressure and experiences a diminishing effect until the high pressure antinode returns to the center of the vessel. The bubble continues to occupy more or less the same space due to the acoustic radiation force, the Bjerknes force, and the buoyancy force of the bubble. | 0 | Luminescence |
Records of bioluminescence due to bacteria have existed for thousands of years. They appear in the folklore of many regions, including Scandinavia and the Indian subcontinent. Both Aristotle and Charles Darwin have described the phenomenon of the oceans glowing. Since its discovery less than 30 years ago, the enzyme luciferase and its regulatory gene, lux, have led to major advances in molecular biology, through use as a reporter gene. Luciferase was first purified by McElroy and Green in 1955. It was later discovered that there were two subunits to luciferase, called subunits α and β. The genes encoding these enzymes, luxA and luxB, respectively, were first isolated in the lux operon of Aliivibrio fisheri. | 1 | Bioluminescence |
Because the compounds that exhibit bioluminescence are typically fluorescent, fluorescence can be used to identify photocytes in organisms. | 1 | Bioluminescence |
A variety of organisms regulate their light production using different luciferases in a variety of light-emitting reactions. The majority of studied luciferases have been found in animals, including fireflies, and many marine animals such as copepods, jellyfish, and the sea pansy. However, luciferases have been studied in luminous fungi, like the Jack-O-Lantern mushroom, as well as examples in other kingdoms including bioluminescent bacteria, and dinoflagellates. | 1 | Bioluminescence |
Phosphorescent paint is commonly called "glow-in-the-dark" paint. It is made from phosphors such as silver-activated zinc sulfide or doped strontium aluminate, and typically glows a pale green to greenish-blue color. The mechanism for producing light is similar to that of fluorescent paint, but the emission of visible light persists long after it has been exposed to light. Phosphorescent paints have a sustained glow which lasts for up to 12 hours after exposure to light, fading over time.
This type of paint has been used to mark escape paths in aircraft and for decorative use such as "stars" applied to walls and ceilings. It is an alternative to radioluminescent paint. Kenners Lightning Bug Glo-Juice was a popular non-toxic paint product in 1968, marketed at children, alongside other glow-in-the-dark toys and novelties. Phosphorescent paint is typically used as body paint, on childrens walls and outdoors.
When applied as a paint or a more sophisticated coating (e.g. a thermal barrier coating), phosphorescence can be used for temperature detection or degradation measurements known as phosphor thermometry. | 0 | Luminescence |
* Stilbene will typically have the chemistry of a diarylethene, a conjugated alkene.
* Stilbene can undergo photoisomerization under the influence of UV light.
* Stilbene can undergo stilbene photocyclization, an intramolecular reaction.
* (Z)-Stilbene can undergo electrocyclic reactions. | 0 | Luminescence |
Aequorin is a holoprotein composed of two distinct units, the apoprotein that is called apoaequorin, which has an approximate molecular weight of 21 kDa, and the prosthetic group coelenterazine, the luciferin. This is to say, apoaequorin is the enzyme produced in the photocytes of the animal, and coelenterazine is the substrate whose oxidation the enzyme catalyzes. When coelenterazine is bound, it is called aequorin. Notably, the protein contains three EF hand motifs that function as binding sites for Ca ions. The protein is a member of the superfamily of the calcium-binding proteins, of which there are some 66 subfamilies.
The crystal structure revealed that aequorin binds coelenterazine and oxygen in the form of a peroxide, coelenterazine-2-hydroperoxide. The binding site for the first two calcium atoms show a 20 times greater affinity for calcium than the third site. However, earlier claims that only two EF-hands bind calcium were questioned when later structures indicated that all three sites can indeed bind calcium. Thus, titration studies show that all three calcium-binding sites are active but only two ions are needed to trigger the enzymatic reaction.
Other studies have shown the presence of an internal cysteine bond that maintains the structure of aequorin. This has also explained the need for a thiol reagent like beta mercaptoethanol in the regeneration of the protein since such reagents weaken the sulfhydryl bonds between cysteine residues, expediting the regeneration of the aequorin.
Chemical characterization of aequorin indicates the protein is somewhat resilient to harsh treatments. Aequorin is heat resistant. Held at 95 °C for 2 minutes the protein lost only 25% activity. Denaturants such as 6-M urea or 4-M guanidine hydrochloride did not destroy the protein. | 1 | Bioluminescence |
Stilbene exists as two possible stereoisomers. One is trans-1,2-diphenylethylene, called (E)-stilbene or trans-stilbene. The second is cis-1,2-diphenylethylene, called (Z)-stilbene or cis-stilbene, and is sterically hindered and less stable because the steric interactions force the aromatic rings out-of-plane and prevent conjugation. Cis-stilbene is a liquid at room temperature (melting point: ), while trans-stilbene is a crystalline solid which does not melt until around , illustrating the two isomers have significantly different physical properties. | 0 | Luminescence |
Glow sticks are used for outdoor recreation, often used at night for marking. Scuba divers use diving-rated glow sticks to mark themselves during night dives, and then can turn off bright diving lights. This is done to enable visibility of bioluminescent marine organisms, which cannot be seen while a bright dive light is illuminated. Glow sticks are used on backpacks, tent pegs, and on jackets during overnight camping expeditions. Often, glow sticks are recommended as an addition to survival kits. | 0 | Luminescence |
Coelenteramine is a metabolic product of the bioluminescent reactions in organisms that utilize coelenterazine. It was first isolated from Aequorea victoria along with coelenteramide after coelenterates were stimulated to emit light. | 1 | Bioluminescence |
Nemoto & Co., Ltd. – a global manufacturer of phosphorescent pigments and other specialized phosphors – was founded by Kenzo Nemoto in December 1941 as a luminous paint processing company and has supplied and developed luminous paint to the watch and clock and aviation instruments industry since.
Super-LumiNova is based on LumiNova branded pigments, invented in 1993 by the Nemoto staff members Yoshihiko Murayama, Nobuyoshi Takeuchi, Yasumitsu Aoki and Takashi Matsuzawa as a safe replacement for radium-based luminous paints. The invention was patented by Nemoto & Co., Ltd. and licensed to other manufacturers and watch brands.
In 1998 Nemoto & Co. established a join-venture with RC Tritech AG called LumiNove AG, Schweitz to manufacture 100 percent Swiss made afterglow pigments branded as Super-LumiNova. After that, the production of radioactive luminous compounds by RC Tritech AG was completely stopped. According to RC Tritech AG the Swiss watch brands all use their Super-LumiNova pigments. | 0 | Luminescence |
An anode ray (also positive ray or canal ray) is a beam of positive ions that is created by certain types of gas-discharge tubes. They were first observed in Crookes tubes during experiments by the German scientist Eugen Goldstein, in 1886. Later work on anode rays by Wilhelm Wien and J. J. Thomson led to the development of mass spectrometry. | 0 | Luminescence |
James Camerons core idea for the Avatars fictional creatures was for them to be "superslick and aerodynamic, and be like a race car with racing stripes". Neville Page worked on Avatar as the lead creature designer. He, Wayne Barlowe (author, artist, and initial lead creature designer), and Yuri Bartoli (concept designer and supervising virtual art director) adapted Camerons conceptions of the fauna into a design that served three purposes: to appear expressive, to function with animation technology, and to seem realistic. He and creature designer Wayne Barlowe sought to base the design of Pandora's creatures on race cars, but they struggled to adapt the concept. Page drew on his education in automotive design, recognizing the irony that race cars were based on real-life animals in having "bone lines". Existing automotive designs drew from seashells, turtle shells, and insects, so the designers returned the design to the fictional creatures. They found that the prime challenge in designing most creatures was to give them organic appearances, including skin texture. Some creatures were also designed to have special breathing holes located in the trachea, copying how cars have intakes. Challenges that the creatures posed for visual effects technicians were to form "walk and run" cycles for six-legged creatures and to impart credible flying for creatures that had four wings. Many of the animals also have four eyes, with an apparent major and minor eye on either side of their head.
The fictional creatures are not connected telepathically according to Cameron and the designers. However, even though they discussed the idea of the creatures being part of Pandoras "Worldmind", they preferred to interpret the creatures as having heightened instincts. Page explained, "Animals are hooked up to this planet. Were the ones who are detached.... The way I dealt with it was, We have so much rich [material] here to reference, that we don't have to dream up a whole new process of animal awareness."
The fictional moon has less gravity than Earth, so the creatures larger sizes match their environment. Most Pandoran wildlife is hexapodal, or six-legged. Much of the fauna and flora is bioluminescent, which is seen in creatures on Earth such as fireflies, many deep sea animals, and some microscopic algae. The aforementioned breathing holes, located on multiple parts of a creatures body other than the mouth, are similar to spiracles in some of Earths animals. The flying reptile-like creatures in the film can be compared to extinct flying reptiles such as pterosaurs and to the modern gliding lizard Draco sumatranus'. | 1 | Bioluminescence |
Raphaël Horace Dubois (20 June 1849, Le Mans – 21 January 1929) was a French pharmacologist known for his work on bioluminescence and anesthesia. He coined the terms proteon and bioproteon, from the Greek "proteon" for matter and "bios" for life. Bioproteon means "living matter". He concluded that there was no difference between matter and living matter.
Dubois bioluminescence work began when he became a research assistant to Paul Bert in 1882. While initially planning to study the effects of anesthesia on mollusks, witnessing the bioluminescence of Pyrophorus noctilucus inspired him to study the beetle more in depth. Dubois discovered that not only do the adults glow, but so do the unfertilized eggs, embryo, and larvae. Dubois later conducted studies on Scolioplanes crassipes, wherein Dubois discovered the source of its luminescence is in cells of the wall of the gut. Dubois published a paper studying the light production of Pholas dactylus' in 1887, in which he coined the terms luciferin and luciferase. | 1 | Bioluminescence |
Luminous paint (or luminescent paint) is paint that emits visible light through fluorescence, phosphorescence, or radioluminescence. | 0 | Luminescence |
According to Entertainment Weekly, "The Navi can commune with animals on their planet by literally plugging their braid into the creatures nerve systems. To become a warrior, a Navi must tame and ride a flying creature known as Ikran." The Navi also use this neural bonding system, called "tsaheylu", to mate with a "life partner", a bond that, when made, cannot be broken in the Navis lifetime. This is akin to human marriage.
The Navi way of life revolves around their religion, and the Home Tree. The Navi sleep in hammocks in large groups for comfort and as a warning system.
Conceived for the film was the Navi language, a constructed language often spoken by the actors when they played Navi characters. The Navi language was created by communications professor emeritus and linguistics consultant Paul Frommer of the University of Southern California. He designed the language so as to be speakable by human actors, combining syntactic and grammatical rules from other existing languages. Frommer created over a thousand words for the Navi language and coached the actors who narrated Navi characters. When communicating to humans in the film, Navi characters – especially Neytiri – speak in accented and broken English.
Human visitors see the Navi as possessing a religion, whose chief and possibly sole deity is a benevolent goddess known as Eywa. The Navi are able to physically connect to Eywa when they use their braids to connect to the Tree of Souls and other similar flora which function as the global brain's interfaces. Eywa is said to have a connection to all things Pandoran.
Political power is exceedingly diffused, with each clan being a sovereign entity under either the diarchical rule of both a temporal chieftain (known as an Oloeyktan) and a spiritual chieftain (known as a Tsahik), or the monarchical rule of a single individual who holds the two separate offices simultaneously. The numerous clans are seemingly only ever brought together as a tribe by Toruk Makto, a messianic war chief whose office is both non-permanent and apparently the only one with an authority that covers the entire race of Navi. By the time of the film, there had only been five Toruk Maktos in the history of the tribe, and the last one had ruled no fewer than four generations before the present day. This may be due to the fact that the Toruk Maktos seem to draw their power from a situation of explicitly external danger, and therefore are not really necessary for the day to day internal running of the tribal clans. Succession to the various offices is smooth, however, based more on popular recognition and customary worthiness than on anything else, and respect for hierarchical superiors appears to be high. | 1 | Bioluminescence |
The property of photoconverted fluorescence Kaede protein was serendipitously discovered and first reported by Ando et al. in Proceedings of the United States National Academy of Sciences. An aliquot of Kaede protein was discovered to emit red fluorescence after being left on the bench and exposed to sunlight. Subsequent verification revealed that Kaede, which is originally green fluorescent, after exposure to UV light is photoconverted, becoming red fluorescent. It was then named Kaede. | 1 | Bioluminescence |
Some other phosphors commercially available, for use as X-ray screens, neutron detectors, alpha particle scintillators, etc., are:
*GdOS:Tb (P43), green (peak at 545 nm), 1.5 ms decay to 10%, low afterglow, high X-ray absorption, for X-ray, neutrons and gamma
*GdOS:Eu, red (627 nm), 850 μs decay, afterglow, high X-ray absorption, for X-ray, neutrons and gamma
*GdOS:Pr, green (513 nm), 7 μs decay, no afterglow, high X-ray absorption, for X-ray, neutrons and gamma
*, green (513 nm), 4 μs decay, no afterglow, high X-ray absorption, for X-ray, neutrons and gamma
*YOS:Tb (P45), white (545 nm), 1.5 ms decay, low afterglow, for low-energy X-ray
*YOS:Eu (P22R), red (627 nm), 850 μs decay, afterglow, for low-energy X-ray
*YOS:Pr, white (513 nm), 7 μs decay, no afterglow, for low-energy X-ray
* (HS), green (560 nm), 80 μs decay, afterglow, efficient but low-res X-ray
* (HSr), red (630 nm), 80 μs decay, afterglow, efficient but low-res X-ray
*CdWO, blue (475 nm), 28 μs decay, no afterglow, intensifying phosphor for X-ray and gamma
*CaWO, blue (410 nm), 20 μs decay, no afterglow, intensifying phosphor for X-ray
*MgWO, white (500 nm), 80 μs decay, no afterglow, intensifying phosphor
*YSiO:Ce (P47), blue (400 nm), 120 ns decay, no afterglow, for electrons, suitable for photomultipliers
*YAlO:Ce (YAP), blue (370 nm), 25 ns decay, no afterglow, for electrons, suitable for photomultipliers
*YAlO:Ce (YAG), green (550 nm), 70 ns decay, no afterglow, for electrons, suitable for photomultipliers
* (YGG), green (530 nm), 250 ns decay, low afterglow, for electrons, suitable for photomultipliers
*CdS:In, green (525 nm), <1 ns decay, no afterglow, ultrafast, for electrons
*ZnO:Ga, blue (390 nm), <5 ns decay, no afterglow, ultrafast, for electrons
*ZnO:Zn (P15), blue (495 nm), 8 μs decay, no afterglow, for low-energy electrons
* (P22G), green (565 nm), 35 μs decay, low afterglow, for electrons
* (P22G), green (540 nm), 35 μs decay, low afterglow, for electrons
* (P20), green (530 nm), 80 μs decay, low afterglow, for electrons
*ZnS:Ag (P11), blue (455 nm), 80 μs decay, low afterglow, for alpha particles and electrons
*anthracene, blue (447 nm), 32 ns decay, no afterglow, for alpha particles and electrons
*plastic (EJ-212), blue (400 nm), 2.4 ns decay, no afterglow, for alpha particles and electrons
*ZnSiO:Mn (P1), green (530 nm), 11 ms decay, low afterglow, for electrons
*ZnS:Cu (GS), green (520 nm), decay in minutes, long afterglow, for X-rays
*NaI:Tl, for X-ray, alpha, and electrons
*CsI:Tl, green (545 nm), 5 μs decay, afterglow, for X-ray, alpha, and electrons
*LiF/ZnS:Ag (ND), blue (455 nm), 80 μs decay, for thermal neutrons
* (NDg), green (565 nm), 35 μs decay, for neutrons
*Cerium doped YAG phosphor, yellow, used in white LEDs for turning blue to white light with a broad spectrum of light | 0 | Luminescence |
Life That Glows (also known as David Attenborough’s Light on Earth) is a 2016 British nature documentary programme made for BBC Television, first shown in the UK on BBC Two on 9 May 2016. The programme is presented and narrated by Sir David Attenborough.
Life That Glows depicts the biology and ecology of bioluminescent organisms, that is, organisms capable of creating light. The programme features fireflies, who use light as a means of sexual attraction, luminous fungi, luminous marine bacteria responsible for the Milky seas effect, the flashlight fish, the aposematism of the Sierra luminous millipede, earthworms, and the bioluminescent tides created by blooms of dinoflagellates in Tasmania, as well as dolphins swimming in the bloom in the Sea of Cortez, the defensive flashes of brittle stars and ostracods, sexual attraction in ostracods, prey attraction by luminous click beetles in Cerrado, Brazil and Arachnocampa gnats in New Zealand.
The programme then introduces many luminous deep sea animals, including the vampire squid, the polychaete worm Tomopteris that generates yellow light, the jellyfish Atolla, the comb jelly Beroe, the viper fish, pyrosomes, a dragonfish, and the polychaete worm Flota. Next, the programme discusses specialised adaptations in the eyes of particular animals to see bioluminescence, such as the barreleye fish and the cock-eyed squid. Lastly, the programme features the mass spawning event of the firefly squid in Japan. | 1 | Bioluminescence |
Luciferins have been shown to be largely conserved among different species while luciferases show a greater degree of diversity. Eighty percent of the species that exhibit bioluminescence exist in aquatic habitats. | 1 | Bioluminescence |