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77,529,364 | https://en.wikipedia.org/wiki/NGC%202342 | NGC 2342 is a spiral galaxy in the constellation of Gemini. Its velocity with respect to the cosmic microwave background is 5445 ± 11 km/s, which corresponds to a Hubble distance of 80.31 ± 5.62 Mpc (∼262 million light-years). It was discovered by German astronomer Albert Marth on 10 November 1864.
NGC 2342 is a luminous infrared galaxy (LIRG). Together with NGC 2341, they both form a gravitationally bound galaxy pair listed as HOLM 86.
One supernova has been observed in NGC 2342: SN 2023vck (type Ib, mag 19.917) was discovered by the Zwicky Transient Facility on 15 October 2023.
See also
List of NGC objects (2001–3000)
References
External links
2342
020265
03709
Gemini (constellation)
18641110
Discoveries by Albert Marth
+03-19-004
Spiral galaxies
Luminous infrared galaxies | NGC 2342 | [
"Astronomy"
] | 194 | [
"Gemini (constellation)",
"Constellations"
] |
77,531,388 | https://en.wikipedia.org/wiki/NGC%203974 | NGC 3974 is a lenticular galaxy in the constellation of Crater. Its velocity with respect to the cosmic microwave background is 6099 ± 41 km/s, which corresponds to a Hubble distance of 89.96 ± 6.34 Mpc (∼293 million light-years). However, one non-redshift measurement gives a much closer distance of . It was discovered by British astronomer John Herschel on 9 March 1828.
NGC 3974 is possibly a LINER galaxy, i.e. it has a type of nucleus that is defined by its spectral line emission which has weakly ionized or neutral atoms, while the spectral line emission from strongly ionized atoms is relatively weak.
One supernova has been observed in NGC 3974: SN 2024gra (type Ia, mag 18.8625) was discovered by the Automatic Learning for the Rapid Classification of Events (ALeRCE) on 16 April 2024.
See also
List of NGC objects (3001–4000)
References
External links
3974
037452
Crater (constellation)
18280309
Discoveries by John Herschel
-02-31-001
Lenticular galaxies
LINER galaxies | NGC 3974 | [
"Astronomy"
] | 237 | [
"Crater (constellation)",
"Constellations"
] |
77,531,717 | https://en.wikipedia.org/wiki/Benzgalantamine | Benzgalantamine, sold under the brand name Zunveyl, is a medication used for the treatment of mild to moderate dementia of the Alzheimer's type. It is a cholinesterase inhibitor. Benzgalantamine is a prodrug of galantamine.
The most common side effects include nausea, vomiting, diarrhea, dizziness, headache, and decreased appetite.
Benzgalantamine was approved for medical use in the United States in July 2024.
Medical uses
Benzgalantamine is indicated for the treatment of mild to moderate dementia of the Alzheimer's type in adults.
Side effects
The most common side effects include nausea, vomiting, diarrhea, dizziness, headache, and decreased appetite.
Society and culture
Legal status
Benzgalantamine was approved for medical use in the United States in July 2024.
Names
Benzgalantamine is the international nonproprietary name.
References
External links
Treatment of Alzheimer's disease
Benzoate esters
Prodrugs | Benzgalantamine | [
"Chemistry"
] | 206 | [
"Chemicals in medicine",
"Prodrugs"
] |
77,533,356 | https://en.wikipedia.org/wiki/Exidia%20subsaccharina | Exidia subsaccharina is a species of fungus in the family Auriculariaceae. Basidiocarps (fruit bodies) are gelatinous, reddish brown, button-shaped at first then often coalescing and becoming irregularly effused. It grows on dead branches of pine and is currently known only from France and England. Molecular research, based on cladistic analysis of DNA sequences, has shown that the species is distinct.
Description
Exidia subsaccharina forms reddish to vinaceous brown, gelatinous fruit bodies that are button-shaped at first, typically coalescing with age and becoming irregularly effused, around 10 cm (4 in) across. The upper, spore-bearing surface is smooth to weakly papillate. The spore print is white.
Microscopic characters
The microscopic characters are typical of the genus Exidia. The basidia are ellipsoid and septate. The spores are weakly to distinctly allantoid (sausage-shaped), 12.5 to 17.5 by 4 to 5.5 μm.
Similar species
Fruit bodies of Exidia saccharina also occur on conifers and are not distinguishable in the field, but have smaller basidia and spores (10 to 14 by 3 to 4.5 μm).
Habitat and distribution
Exidia subsaccharina is currently only known from the type collections made on dead trees of Pinus sylvestris in France and a single collection, also on pine, from England.
References
Fungi described in 2023
Fungi of Europe
Auriculariales
Fungus species | Exidia subsaccharina | [
"Biology"
] | 330 | [
"Fungi",
"Fungus species"
] |
77,533,552 | https://en.wikipedia.org/wiki/NGC%202890 | NGC 2890 is a lenticular galaxy in the constellation of Hydra. Its velocity with respect to the cosmic microwave background is 5455 ± 37 km/s, which corresponds to a Hubble distance of 80.45 ± 5.67 Mpc (∼263 million light-years). It was discovered by American astronomer Francis Leavenworth on 11 January 1886.
The SIMBAD database lists NGC 2890 as a Seyfert II Galaxy, i.e. it has a quasar-like nuclei with very high surface brightnesses whose spectra reveal strong, high-ionisation emission lines, but unlike quasars, the host galaxy is clearly detectable.
One supernova has been observed in NGC 2890: SN 2023xnl (type Ia, mag 17.4931) was discovered by the Zwicky Transient Facility on 11 November 2023.
See also
List of NGC objects (2001–3000)
References
External links
2890
026778
Hydra (constellation)
18860111
Discoveries by Francis Leavenworth
-02-24-024
Lenticular galaxies
Seyfert galaxies | NGC 2890 | [
"Astronomy"
] | 227 | [
"Hydra (constellation)",
"Constellations"
] |
77,534,334 | https://en.wikipedia.org/wiki/NGC%201590 | NGC 1590 is a spiral galaxy in the constellation of Taurus. Its velocity with respect to the cosmic microwave background is 3826 ± 8 km/s, which corresponds to a Hubble distance of 56.43 ± 3.95 Mpc (∼184 million light-years). It was discovered by German astronomer Heinrich d'Arrest on 28 October 1865.
One supernova has been observed in NGC 1590: SN 2007rz (type Ic, mag 16.9) was discovered by the Lick Observatory Supernova Search (LOSS) on 8 December 2007.
NGC 1762 Group
NGC 1590 is part of the NGC 1762 Group (also known as LGG 120) that includes at least 27 galaxies, including IC 392, NGC 1633, NGC 1642, NGC 1691, NGC 1713, NGC 1719, and NGC 1762, among others.
See also
List of NGC objects (1001–2000)
References
External links
1590
15368
03071
Taurus (constellation)
18651028
+01-12-008
Spiral galaxies | NGC 1590 | [
"Astronomy"
] | 213 | [
"Taurus (constellation)",
"Constellations"
] |
77,534,683 | https://en.wikipedia.org/wiki/HD%20194688 | HD 194688, also designated as HR 7816, is a solitary star located in the northern constellation Delphinus, the dolphin. It has an apparent magnitude of 6.22, placing it near the limit for naked eye visibility. The object is located relatively far away at a distance of 886 light-years based on Gaia DR3 parallax measurements, but it is drifting closer with a heliocentric radial velocity of . At its current distance, HD 196488's brightness is diminished due to an interstellar extinction of 0.17 magnitudes and it has an absolute visual magnitude of −1.19.
HD 194688 has a simple stellar classification of K0, indicating that it is an early K-type star. It has 1.57 times the mass of the Sun and an enlarged radius 21.58 times that of the Sun. It radiates 258 times the luminosity of the Sun from its photosphere at an effective temperature of , giving it an orangish-yellow hue when viewed in the night sky. The large radius and high luminosity suggests that HD 194688 may be an evolved giant star. It is slightly metal-deficient with an iron abundance 74.1% that of the Sun's.
References
K-type giants
Delphinus
BD+16 04259
194688
100807
7816
000305526917 | HD 194688 | [
"Astronomy"
] | 290 | [
"Delphinus",
"Constellations"
] |
77,534,762 | https://en.wikipedia.org/wiki/Diiodosyl%20sulfate | Diiodosyl sulfate is an inorganic compound, a basic salt of iodine and sulfuric acid with the formula (IO)2SO4. It forms yellow crystals.
Synthesis
Reaction of iodic and sulfuric acids :
2 HIO3 + H2SO4 → (IO)2SO4 + O2 + 2 H2O
Passing ozonized oxygen through a solution of iodine in sulfuric acid:
I2 + 3 O3 + H2SO4 → (IO)2SO4 + 3 O2 + H2O
Physical properties
Diiodosyl sulfate forms yellow hygroscopic crystals and is poorly soluble in cold water.
It dissolves in and can be recrystallized from concentrated sulfuric acid.
Chemical properties
Under the influence of atmospheric moisture, diiodosyl sulfate hydrolyzes with the release of iodine, iodic and sulfuric acids.
It decomposes when heated:
4(IO) 2 SO 4 → 2I2O5 + 2I2 + 4SO3 + O2
It reacts with sulfur trioxide:
(IO)2SO4 + 2SO3 → I2(SO4)3
With concentrated sulfuric acid, it forms an acidic salt:
(IO)2SO4 + H2SO4 → 2 IOHSO4
References
Iodine compounds
Inorganic compounds
sulfates | Diiodosyl sulfate | [
"Chemistry"
] | 277 | [
"Sulfates",
"Inorganic compounds",
"Salts"
] |
77,534,953 | https://en.wikipedia.org/wiki/NGC%207735 | NGC 7735 is an elliptical galaxy in the constellation of Pegasus. Its velocity with respect to the cosmic microwave background is 9249 ± 36 km/s, which corresponds to a Hubble distance of 136.41 ± 9.57 Mpc (∼445 million light-years). It was discovered by British astronomer John Herschel on 5 September 1828.
One supernova has been observed in NGC 7735: SN 2024we (type Ia, mag 17) was discovered by ASAS-SN on 11 January 2024.
See also
List of NGC objects (7001–7840)
References
External links
7735
072165
Pegasus (constellation)
18280905
Discoveries by John Herschel
+04-55-046
Elliptical galaxies
12744 | NGC 7735 | [
"Astronomy"
] | 154 | [
"Pegasus (constellation)",
"Constellations"
] |
77,535,075 | https://en.wikipedia.org/wiki/Laplace%20sphere | In astronomy and orbital mechanics, the Laplace sphere concerns a specific kind of Three-body problem with orbits. The prototype idea is to study the Sun-Earth-Moon system, and determine if it would be possible for the Sun to steal away the Moon from Earth orbit, into solar orbit. More generally, it is applied to any satellite of a body (often called the 'planet') that is, in turn, orbiting a much more massive body (often called the 'star'). Besides the moon, the satellite is usually a small planetoid, exoplanet, or a spacecraft that is orbiting the earth.
The Laplace sphere is a region around a planet where a satellite would maintain a stable orbit around the planet, rather than being pulled off toward the star, with its greater gravitational force, despite its larger distance. The 'sphere' region is actually an ellipsoid, specifically a prolate spheroid with its long axis perpendicular to the star-planet orbit. This results in the fact that the satellite with an eccentric orbit is safer with its apsis pointing up or down, than pointing in the plane of the planet's orbit. The derivation eliminates higher-order terms on the assumption that the star's mass is much larger than the planet's, and the planet's mass is much larger than the satellite's.
See also
Hill sphere
References
Orbits | Laplace sphere | [
"Astronomy"
] | 285 | [
"Astronomy stubs"
] |
77,535,397 | https://en.wikipedia.org/wiki/Photon%20Multiplicity%20Detector | Photon Multiplicity Detector (PMD) is a detector used in the measurement of the multiplicity and spatial distribution of photons produced in nucleus - nucleus collisions. In short form, it is denoted by PMD. It was incorporated in the WA93 experiment. The funding for research and development of the design of PMD was done by the Department of Atomic Energy (DAE) and the Department of Science and Technology (DST) of the Government of India. The detector was constructed in the collaboration of Variable Energy Cyclotron Centre in Kolkata, Institute of Physics in Bhubaneswar and group of universities at Chandigarh, Jaipur and Jammu.
Description
A PMD typically consists of two main layers Veto Detector and Preshower Detector. Veto Detector layer is designed to reject charged particles. Photons pass through a converter in Preshower Detector layer, initiating an electromagnetic shower. The detector then measures the number of cells activated by the shower, providing information about the photon's energy and position.
At ALICE experiment, PMD was used to measure the multiplicity and pseudorapidity density distributions of inclusive photons at forward rapidity, spanning the range η = 2.3 to 3.9. The measurement was conducted using LHC Run 1 and 2 data by PMD in pp (proton - proton collisions), pPb and Pbp collisions at a centre-of-mass energy of 5.02 TeV per nucleon pair.
References
Nuclear physics | Photon Multiplicity Detector | [
"Physics"
] | 303 | [
"Nuclear physics"
] |
70,301,091 | https://en.wikipedia.org/wiki/HTML%20landmarks | HTML landmarks are used to categorize and group content on a web page for better accessibility and SEO.
Sectioning elements
HTML5 included the addition of the following content sectioning elements, which inherit default landmark roles:
Landmark roles
The role attribute is used to define an element's role on a page. When sectioning elements were introduced, the role attribute became used less for landmarking. This is because roles were applied by default to most sectioning elements, therefore, they were more widely used and accepted for their simplicity.
The role attribute is not only used for assigning roles to content sections. The attribute can also be used to assign roles to many other elements, although it is used less nowadays due to new semantic HTML elements.
Examples
<div role="banner">
<h1>Hello, world!</h1>
</div>The code above is the same as the following more widely accepted version:<header>
<h1>Hello, world!</h1>
</header>
Misuse
Following the addition of sectioning elements in HTML5, there was confusion regarding whether role attributes were needed for sectioning elements. It is in fact redundant to give sectioning elements the role attribute.
Additionally, you should not try to alter sectioning elements' default roles.
Examples of misuse
The role of main on the <main> element is useless, as it already inherits that role as its default landmark role:<main role="main">
<p>Hello world!</p>
</main>Applying the form role to <header> is semantically improper, because it overrides <header>'s the default role of banner:<header role="form">
<!--Some HTML code here-->
</header>
See also
Semantic Web
Semantic HTML
Web accessibility
HTML element
HTML attribute
References
Web design
Web accessibility
HTML tags
HTML5
HTML | HTML landmarks | [
"Engineering"
] | 393 | [
"Design",
"Web design"
] |
70,301,343 | https://en.wikipedia.org/wiki/HD%2061563 | HD 61563 is a binary star in the constellation of Canis Minor consisting of two A-type stars with both spectral types A0IV, and the combined apparent magnitude is 6.02, barely visible to the naked eye.
References
Canis Minor
A-type subgiants
Durchmusterung objects
061563
2950
Double stars
Binary stars | HD 61563 | [
"Astronomy"
] | 75 | [
"Canis Minor",
"Constellations"
] |
70,302,266 | https://en.wikipedia.org/wiki/Gamas%27s%20theorem | Gamas's theorem is a result in multilinear algebra which states the necessary and sufficient conditions for a tensor symmetrized by an irreducible representation of the symmetric group to be zero. It was proven in 1988 by Carlos Gamas. Additional proofs have been given by Pate and Berget.
Statement of the theorem
Let be a finite-dimensional complex vector space and be a partition of . From the representation theory of the symmetric group it is known that the partition corresponds to an irreducible representation of . Let be the character of this representation. The tensor symmetrized by is defined to be
where is the identity element of . Gamas's theorem states that the above symmetrized tensor is non-zero if and only if it is possible to partition the set of vectors into linearly independent sets whose sizes are in bijection with the lengths of the columns of the partition .
See also
Algebraic combinatorics
Immanant
Schur polynomial
References
Algebraic combinatorics
Theorems
Multilinear algebra | Gamas's theorem | [
"Mathematics"
] | 210 | [
"Fields of abstract algebra",
"Algebraic combinatorics",
"Combinatorics"
] |
70,302,410 | https://en.wikipedia.org/wiki/4D%20scanning%20transmission%20electron%20microscopy | 4D scanning transmission electron microscopy (4D STEM) is a subset of scanning transmission electron microscopy (STEM) which utilizes a pixelated electron detector to capture a convergent beam electron diffraction (CBED) pattern at each scan location. This technique captures a 2 dimensional reciprocal space image associated with each scan point as the beam rasters across a 2 dimensional region in real space, hence the name 4D STEM. Its development was enabled by evolution in STEM detectors and improvements computational power. The technique has applications in visual diffraction imaging, phase orientation and strain mapping, phase contrast analysis, among others.
The name 4D STEM is common in literature, however it is known by other names: 4D STEM EELS, ND STEM (N- since the number of dimensions could be higher than 4), position resolved diffraction (PRD), spatial resolved diffractometry, momentum-resolved STEM, "nanobeam precision electron diffraction", scanning electron nano diffraction (SEND), nanobeam electron diffraction (NBED), or pixelated STEM.
History
The use of diffraction patterns as a function of position dates back to the earliest days of STEM, for instance the early review of John M. Cowley and John C. H. Spence in 1978 or the analysis in 1983 by Laurence D. Marks and David J. Smith of the orientation of different crystalline segments in nanoparticles. Later work includes the analysis of diffraction patterns as a function of probe position in 1995, where Peter Nellist, B.C. McCallum and John Rodenburg attempted electron ptychography analysis of crystalline silicon. There is also fluctuation electron microscopy (FEM) technique, proposed in 1996 by Treacy and Gibson, which also included quantitative analysis of the differences in images or diffraction patterns taken at different locations on a given sample.
The field of 4D STEM remained underdeveloped due to the limited capabilities of detectors available at the time. The earliest work used either Grigson coils to scan the diffraction pattern, or an optical camera pickup from a phosphur screen. Later on CCD detectors became available, but while these are commonly used in transmission electron microscopy (TEM) they had limited data acquisition rates, could not distinguish where on the detector an electron strikes with high accuracy, and had low dynamic range which made them undesirable for use in 4D STEM.
In the late 2010s, the development of hybrid pixel array detectors (PAD) with single electron sensitivity, high dynamic range, and fast readout speeds allowed for practical 4D STEM experiments.
Operating Principle
While the process of data collection in 4D STEM is identical to that of standard STEM, each technique utilizes different detectors and collects different data. In 4D STEM there is a pixelated electron detector located at the back focal plane which collects the CBED pattern at each scan location. An image of the sample can be constructed from the CBED patterns by selecting an area in reciprocal space and assigning the average intensity of that area in each CBED pattern to the real space pixel the pattern corresponds to.
It is also possible for there to be a(n) ADF or HAADF image taken concurrently with the CBED pattern collection, depending on where the detector is located on the microscope. An annular dark-field image taken may be complementary to a bright-field image constructed from the captured CBED images.
The use of a hollow detector with a hole in the middle can allow for transmitted electrons to be passed to an EELS detector while scanning. This allows for the simultaneous collection of chemical spectra information and structure information.
Detectors
In traditional TEM, imaging detectors use phosphorescent scintillators paired with a charge coupled device (CCD) to detect electrons. While these devices have good electron sensitivity, they lack the necessary readout speed and dynamic range necessary for 4D STEM. Additionally, the use of a scintillator can worsen the point spread function (PSF) of the detector due to the electron's interaction with the scintillator resulting in a broadening of the signal. In contrast, traditional annular STEM detectors have the necessary readout speed, but instead of collecting a full CBED pattern the detector integrates the collected intensity over a range of angles into a single data point. The development of pixelated detectors in the 2010s with single electron sensitivity, fast readout speeds, and high dynamic range has enabled 4D STEM as a viable experimental method.
4D STEM detectors are typically built as either a monolithic active pixel sensor (MAPS) or as a hybrid pixel array detector (PAD).
Monolithic active pixel sensor (MAPS)
A MAPS detector consists of a complementary metal–oxide–semiconductor (CMOS) chip paired with a doped epitaxial surface layer which converts high energy electrons into many lower energy electrons that travel down to the detector. MAPS detectors must be radiation hardened as their direct exposure to high energy electrons makes radiation damage a key concern.
Due to its monolithic nature and straightforward design, MAPS detectors can attain high pixel densities on the order of 4000 x 4000. This high pixel density when paired with low electron doses can enable single electron counting for high efficiency imaging. Additionally, MAPS detectors tend to have electron high sensitivities and fast readout speeds, but suffer from limited dynamic range.
Pixel array detector (PAD)
PAD detectors consist of a photodiode bump bonded to an integrated circuit, where each solder bump represents a single pixel on the detector.
These detectors typically have lower pixel densities on the order of 128 x 128 but can achieve much higher dynamic range on the order of 32 bits. These detectors can achieve relatively high readout speeds on the order of 1 ms/pixel but are still lacking compared to their annular detector counterparts in STEM which can achieve readout speeds on the order of 10 μs/pixel.
Detector noise performance is often measured by its detective quantum efficiency (DQE) defined as:
where is output signal to noise ratio squared and is the input signal to noise ratio squared. Ideally the DQE of a sensor is 1 indicating the sensor generates zero noise. The DQE of MAPS, APS and other direct electron detectors tend to be higher than their CCD camera counterparts.
Computational Methods
A major issue in 4D STEM is the large quantity of data collected by the technique. With upwards of 100s of TB of data produced over the course of an hour of scanning, finding pertinent information is challenging and requires advanced computation.
Analysis of such large datasets can be quite complex and computational methods to process this data are being developed. Many code repositories for analysis of 4D STEM are currently in development including: HyperSpy, , LiberTEM, Pycroscopy, and .
AI driven analysis is possible. However, some methods require databases of information to train on which currently do not exist. Additionally, lack of metrics for data quality, limited scalability due to poor cross-platform support across different manufacturers, and lack of standardization in analysis and experimental methods brings up questions of comparability across different datasets as well as reproducibility.
Selected Applications
4D STEM has been utilized in a wide array of applications, the most common uses include virtual diffraction imaging, orientation and strain mapping, and phase contrast analysis which are covered below. The technique has also been applied in: medium range order measurement, Higher order Laue zone (HOLZ) channeling contrast imaging, Position averaged CBED, fluctuation electron microscopy, biomaterials characterization, and medical fields (microstructure of pharmaceutical materials and orientation mapping of peptide crystals). This list is in no way exhaustive and as the field is still relatively young more applications are actively being developed.
Virtual Diffraction (Dark Field / Bright Field) Imaging
Virtual diffraction imaging is a method developed to generate real space images from diffraction patterns. This technique has been used in characterizing material structures since the 90s but more recently has been applied in 4D STEM applications. This technique often works best with scanning electron nano diffraction (SEND), where the probe convergence angle is relatively low to give separated diffraction disks (thus also giving a resolution measured in nm, not Å). A "virtual detector," is not a detector at all but rather a method of data processing which integrates a subset of pixels in diffraction patterns at each raster position to create a bright-field or dark-field image. A region of interest is selected on some representative diffraction pattern, and only those pixels within the aperture summed to form the image. This virtual aperture can be any size/shape desired and can be created using the 4D dataset gathered from a single scan. This ability to apply different apertures to the same dataset is possible because of having the whole diffraction pattern in the 4D STEM dataset. This eliminates a typical weaknesses in conventional STEM operation as STEM bright-field and dark-field detectors are placed at fixed angles and cannot be changed during imaging.
With a 4D dataset bright/dark-field images can be obtained by integrating diffraction intensities from diffracted and transmitted beams respectively. Creating images from these patterns can give nanometer or atomic resolution information (depending on the pixel step size and the range of diffracted angles used to form the image) and is typically used to characterize the structure of nanomaterials. Additionally, these diffraction patterns can be indexed and analyzed using other 4DSTEM techniques, such as orientation and phase mapping, or strain mapping. A key advantage of performing virtual diffraction imaging in 4D STEM is the flexibility. Any shape of aperture could be used: a circle (cognate with traditional TEM bright/dark field imaging), a rectangle, an annulus (cognate with STEM ADF/ABF imaging), or any combination of apertures in a more complex pattern. The use of regular grids of apertures is particularly powerful at imaging a crystal with high signal to noise and minimising the effects of bending and has been used by McCartan et al.; this also allowed the imaging of an array of superlattice spots associated with a particular crystal ordering in part of the crystal as a result of chemical segregation.
Virtual diffraction imaging has been used to map interfaces, select intensity from selected areas of the diffraction plane to form enhanced dark field images, map positions of nanoscale precipitates, create phase maps of beam sensitive battery cathode materials, and measure degree of crystallinity in metal-organic frameworks (MOFs).
Recent work has further extended the possibilities of virtual diffraction imaging, by applying a more digital approach adapted from one developed for orientation and phase mapping, or strain mapping. In these methods, the diffraction spot positions in a 4D dataset are determined for each diffraction pattern and turned into a list, and operations are performed on the list, not on the whole images. For dark field imaging, the centroid positions for the list of diffraction spots can be simply compared against a list of centroid positions for where spots are expected and intensity only added where diffraction spot centroids agree with the selected positions. This gives far more selectivity than simply integrating all intensity in an aperture (particularly because it ignores diffuse intensity that does not fall in spots), and consequently, much higher contrast in the resulting images and has recently been submitted to arXiv.
Phase Orientation Mapping
Phase orientation mapping is typically done with electron back scattered diffraction in SEM which can give 2D maps of grain orientation in polycrystalline materials. The technique can also be done in TEM using Kikuchi lines, which is more applicable for thicker samples since formation of Kikuchi lines relies on diffuse scattering being present. Alternatively, in TEM one can utilize precession electron diffraction (PED) to record a large number of diffraction patterns and through comparison to known patterns, the relative orientation of grains in can be determined. 4D STEM can also be used to map orientations, in a technique called Bragg spot imaging. The use of traditional TEM techniques typically results in better resolution than the 4D STEM approach but can fail in regions with high strain as the DPs become too distorted.
In Bragg spot imaging, first correlation analysis method is performed to group diffraction patterns (DPs) using a correlation method between 0 (no correlation) and 1 (exact match); then the DP's are grouped by their correlation using a correlation threshold. A correlation image can then be obtained from each group. These are summed and averaged to obtain an overall representative diffraction template from each grouping. Different orientations can be assigned colors which helps visualize individual grain orientations. With proper tilting and utilizing precession electron diffraction (PED) it is even possible to make 3D tomographic renderings of grain orientation and distribution. Since the technique is computationally intensive, recent efforts have been focused on a machine learning approach to analysis of diffraction patterns.
Strain Mapping
TEM can measure local strains and is often used to map strain in samples using condensed beam electron diffraction CBED. The basis of this technique is to compare an unstrained region of the sample's diffraction pattern with a strained region to see the changes in the lattice parameter. With STEM, the disc positions diffracted from an area of a specimen can provide spatial strain information. The use of this technique with 4D STEM datasets includes fairly involved calculations.
Utilizing SEND, bright and dark field images can be obtained from diffraction patterns by integration of direct and diffracted beams respectively, as discussed previously. During 4D STEM operation the ADF detector can be used to visualize a particular region of interest through a collection of scattered electrons to large angles to correlate probe location with diffraction during measurements. There is a tradeoff between resolution and strain information; since larger probes can average strain measurements over a large volume, but moving to smaller probe sizes gives higher real space resolution. There are ways to combat this issue such as spacing probes further apart than the resolution limit to increase the field of view.
This strain mapping technique has been applied in many crystalline materials and has been extended to semi-crystalline and amorphous materials (such as metallic glasses) since they too exhibit deviations from mean atomic spacing in regions of high strain
Phase Contrast Analysis
Differential phase contrast
The differential phase contrast imaging technique (DPC) can be used in STEM to characterise magnetic and electric fields inside a thin specimen. The electric or magnetic field in samples is estimated by measuring the deflection of the electron beam caused by the field at each scan point. This differs from the more traditional annular dark field (ADF) measurements by the placement of the detector in the bright field area such that the center of mass of the (mostly) unscattered electron beam may be measured. Additionally, segmented or pixelated detectors are used in order to gain the necessary radial resolution. ADF detectors are typically monolithic (single-segment) and are placed in the dark field region, such that they collect the electrons that have been scattered by the sample. Using DPC to image the local electric fields surrounding single atoms or atomic columns is possible. The use of a pixelated detector in 4D STEM and a computer to track the movement of the "center of mass" of the CBED patterns was found to provide comparable results to those found using segmented detectors. 4D STEM allows for phase change measurements along all directions to be measured without the need to rotate the segmented detector to align with specimen orientation. The ability to measure local polarization in parallel with the local electric field has also been demonstrated with 4D STEM.
DPC imaging with 4D STEM is up to 2 orders of magnitude slower than DPC with segmented detectors and requires advanced analysis of large four-dimensional datasets.
Ptychography
The overlapping CBED measurements present in a 4D STEM dataset allow for the construction of the complex electron probe and complex sample potential using the ptychography technique. Ptychographic reconstructions with 4D STEM data were shown to provide higher contrast than ADF, BF, ABF, and segmented DPC imaging in STEM. The high signal-to-noise ratio of this technique under 4D STEM makes it attractive for imaging radiation sensitive specimens such as biological specimens The use of a pixelated detector with a hole in the middle to allow the unscattered electron beam to pass to a spectrometer has been shown to allow ptychographic analysis in conjunction with chemical analysis in 4D STEM.
MIDI STEM
This technique MIDI-STEM (matched illumination and detector interferometry-STEM), while being less common, is used with ptychography to create higher contrast phase images. The placement of a phase plate with zones of 0 and π/2 phase shift in the probe forming aperture creates a series of concentric rings in the resulting CBED pattern. The difference in counts between the 0 and π/2 regions allows for direct measurement of local sample phase. The counts in the different regions could be measured via complex standard detector geometries or the use of a pixelated detector in 4D STEM. Pixelated detectors have been shown to utilize this technique with atomic resolution.
(MIDI)-STEM produces image contrast information with less high-pass filtering than DPC or ptychography but is less efficient at high spatial frequencies than those techniques. (MIDI)-STEM used in conjunction with ptychography has been shown to be more efficient in providing contrast information than either technique individually.
See also
Electron diffraction
Detectors for transmission electron microscopy
Energy filtered transmission electron microscopy (EFTEM)
High-resolution transmission electron microscopy (HRTEM)
Scanning confocal electron microscopy (SCEM)
Scanning electron microscope (SEM)
Scanning Transmission Electron Microscopy (STEM)
Transmission electron microscopy (TEM)
References
Electron beam
Electron microscopy techniques | 4D scanning transmission electron microscopy | [
"Chemistry"
] | 3,706 | [
"Electron",
"Electron beam"
] |
70,302,736 | https://en.wikipedia.org/wiki/Dilauroyl%20peroxide | Dilauroyl peroxide is an organic compound with the formula (C11H23CO2)2. A colorless solid, it is often sold as a water-damped solid. It is the symmetrical peroxide of lauric acid. It is produced by treating lauroyl chloride with hydrogen peroxide in the presence of base:
2C11H23COCl + H2O2 + 2NaOH → (C11H23CO2)2 + 2HCl
References
Organic peroxides
Radical initiators | Dilauroyl peroxide | [
"Chemistry",
"Materials_science"
] | 111 | [
"Radical initiators",
"Organic compounds",
"Polymer chemistry",
"Reagents for organic chemistry",
"Organic peroxides"
] |
70,303,561 | https://en.wikipedia.org/wiki/Prize%20of%20the%20Verkhovna%20Rada%20of%20Ukraine | The Prize of the Verkhovna Rada of Ukraine, for young scientists in the field of basic and applied research and scientific and technological research works, was established to promote domestic science and technology, increase the participation of young scientists in interdisciplinary basic and applied research and scientific development and increasing the prestige of the researcher. The award was established by the Verkhovna Rada of Ukraine in 2007.
Every year, since January 1, 2008, 20 Prizes of the Verkhovna Rada of Ukraine are awarded to young scientists. The awardees also receive a sum of ₴20 thousand each.
Laureates
Tetiana Ivanova
Oleksandr Kolodiazhnyi
References
Awards of the Verkhovna Rada of Ukraine
Ukrainian awards
State Prizes of Ukraine
Badges | Prize of the Verkhovna Rada of Ukraine | [
"Mathematics",
"Technology"
] | 157 | [
"Science and technology awards",
"Science award stubs",
"Symbols",
"Badges"
] |
70,303,781 | https://en.wikipedia.org/wiki/Atena%20Pashko | Atena-Sviatomyra Vasylivna Pashko (; 10 October 1931 – 20 March 2012) was a Ukrainian chemical engineer, poet, and social activist in the Ukrainian rights movement. Her published poetry collections include, On the crossroads (На перехрестях), Volume 1, 1989; On the tip of a candle (На вістрі свічки), 1991; and The blade of my trail (Лезо моєї стежки), 2007.
Pashko was the Chair of the Union of Ukrainian Women (1991), and served as president of the Viacheslav Chornovil International Charitable Foundation (1999). Administratively repressed during the Soviet era, she was later a recipient of the Order of Princess Olga and the Order of Liberty.
Biography
Athena Pashko was born on 10 October 1931 in the village of Bystrytsia, Drohobych district, Lwów Voivodeship, an administrative unit of interwar Poland. She graduated from Ukrainian National Forestry University.
Since the mid-1960s, she was persecuted and banned from publishing her works for defending repressed Ukrainian cultural figures. A reprimand was announced at her place of work, and searches were conducted in her apartment. In 1970, she signed an appeal to the Supreme Court of the Ukrainian Soviet Socialist Republic with a demand to overturn the sentence of Veronica Morozova, for which she was fired. Pashko was constantly under KGB surveillance. In December 1991, the founding congress of the Ukrainian Women's Union took place in Kyiv, and Pashko was elected chair of the Union. She later held the title of, Honorary Chair of the Union of Ukrainian Women. After the tragic death of her husband, Viacheslav Chornovil, on 25 March 1999 in a car accident, Pashko continued her political mission, and was even called the guardian of the People's Movement of Ukraine. She died in Kyiv on 20 March 2012, and was buried in Kyiv at the Baikove Cemetery, next to her husband.
Legacy
Athena Pashko Street in Buchach is named in her honor.
Awards
18 August 1997, Order of Princess Olga, 3rd class, for outstanding personal contribution to the spiritual revival of Ukraine, solving the problems of family, women and children, professional and social activities for the benefit of the Ukrainian people
18 November 2009, Order of Liberty, for outstanding personal contribution to the defense of the national idea, the formation and development of the independent Ukrainian state, and active political and social activities
Selected works
Poetry collections
На перехрестях, Volume 1, 1989
На вістрі свічки, 1991
Лезо моєї стежки, 2007
References
1931 births
2012 deaths
20th-century Ukrainian poets
20th-century Ukrainian women writers
21st-century Ukrainian poets
21st-century Ukrainian women writers
Burials at Baikove Cemetery
Chemical engineers
People from Lwów Voivodeship
Recipients of the Order of Princess Olga, 3rd class
Ukrainian women activists
Ukrainian National Forestry University alumni
Ukrainian women poets
Recipients of the Order of Liberty (Ukraine) | Atena Pashko | [
"Chemistry",
"Engineering"
] | 661 | [
"Chemical engineering",
"Chemical engineers"
] |
70,303,788 | https://en.wikipedia.org/wiki/Papiliotrema%20laurentii | Papiliotrema laurentii (synonym Cryptococcus laurentii) is a species of fungus in the family Rhynchogastremaceae. It is typically isolated in its yeast state.
In its yeast state, it is a rare human pathogen, able to provoke a skin condition, or fungemia in immunocompromised hosts.
It can also be used as sole source of food for the rearing of Caenorhabditis elegans.
References
Tremellomycetes
Yeasts
Fungal pathogens of humans
Fungus species
Fungi described in 1920 | Papiliotrema laurentii | [
"Biology"
] | 118 | [
"Yeasts",
"Fungi",
"Fungus species"
] |
70,304,544 | https://en.wikipedia.org/wiki/Mrakia%20aquatica | Mrakia aquatica is a species of fungus in the family Mrakiaceae. It is only known from its yeast state, originally isolated from lake water in England.
Description
The species has an optimal growth temperature of 9 °C, but can grow at temperatures as low as 2 °C. When plated on agar it produces smooth, butyrous colonies that are cream. When grown in liquid media it takes approximately 76 hours to reach stationary phase and is very sensitive to decreases in pH. Cells are typically oval or cylindrical, but can be dumb-bell shaped. Mrakia aquatica reproduces through bipolar mypodial budding. It can weakly ferment D-glucose, D-galactose, maltose and melezitose. This species is DBB+. Mrakia aquatica has been studied because of its ability to produce pecticase. It produces polycalacturonase, but not isoenzymes of polygalacturonase, and it has increased activity in the presence of glucose. The species has an interesting trait in that it produces mycocins, which are proteinaceous toxins that either kill or inhibit the ability of fungi that are in the same taxonomic rank or in a related taxonomic rank. The mycocin that M. aquatica produces is only able to kill species in the Cystofilobasidiales.
References
Tremellomycetes
Fungi of Europe
Fungi described in 1966
Yeasts
Fungus species | Mrakia aquatica | [
"Biology"
] | 298 | [
"Yeasts",
"Fungi",
"Fungus species"
] |
70,304,653 | https://en.wikipedia.org/wiki/BRI%201335-0417 | BRI 1335-0417 is the most distant known spiral galaxy as of 2021. It is located in the Virgo constellation. The galaxy has a redshift of 4.4, meaning its light took 12.4 billion years to reach Earth, when the universe was 1.4 billion years old, and its present comoving distance is about 25 billion light-years. It is discovered by ALMA, led by Takafumi Tsukui and his colleague, professor Satoru Iguchi from SOKENDAI, and the National Astronomical Observatory of Japan, in May 2021.
See also
BX442, an old and distant spiral galaxy
A1689B11, another old and distant spiral galaxy
References
External links
on SIMBAD
Spiral galaxies
Virgo (constellation)
Dwarf spiral galaxies
Astronomical objects discovered in 2021 | BRI 1335-0417 | [
"Astronomy"
] | 166 | [
"Virgo (constellation)",
"Constellations"
] |
70,304,770 | https://en.wikipedia.org/wiki/%CE%92-Thromboglobulin | β-Thromboglobulin (β-TG), or beta-thromboglobulin, is a chemokine protein secreted by platelets. It is a type of chemokine (C-X-C motif) ligand 7. Along with platelet factor 4 (PF4), β-TG is one of the best-characterized platelet-specific proteins. β-TG and PF4 are stored in platelet alpha granules and are released during platelet activation. As a result, they are useful markers of platelet activation. β-TG also has multiple biological activities, for instance being involved in maturation of megakaryocytes.
Biological actions
β-TG is a chemoattractant, strongly for fibroblasts and weakly for neutrophils. It is a stimulator of mitogenesis, extracellular matrix synthesis, glucose metabolism, and plasminogen activator synthesis in human fibroblasts.
β-TG also affects megakaryocyte maturation, and thus helps in regulating platelet production.
Clinical uses
Levels of β-TG is used to index platelet activation. It is measured by ELISA in blood plasma or urine, and often in conjunction with PF4.
Influences
β-TG levels may increase with age. It is elevated in diabetes mellitus.
β-TG levels have been found to be increased by treatment with the synthetic estrogen ethinylestradiol, though were not significantly increased by the natural estrogen estradiol valerate. Levels of β-TG have also been found to be increased or unchanged during normal pregnancy.
References
Blood proteins
Coagulation system
Cytokines
Hematology | Β-Thromboglobulin | [
"Chemistry",
"Biology"
] | 366 | [
"Biotechnology stubs",
"Signal transduction",
"Biochemistry stubs",
"Cytokines",
"Biochemistry"
] |
70,307,173 | https://en.wikipedia.org/wiki/Gregatin%20B | Gregatin B is a metabolite of the fungi Cephalosporium gregatum and Aspergillus panamensis with the molecular formula C14H18O4 Gregatin B is a weak antibiotic. Gregatin B was discovered in 1982 and has been the subject of total synthesis.
References
Further reading
Gregatin B
Antibiotics
Cyclopentenes
Methyl esters | Gregatin B | [
"Chemistry",
"Biology"
] | 79 | [
"Antibiotics",
"Biocides",
"Biotechnology products"
] |
70,308,280 | https://en.wikipedia.org/wiki/Guisinol | Guisinol is an antibacterial depside with the molecular formula C23H25ClO5 that has been isolated from the fungus Aspergillus unguis.
References
Further reading
Chloroarenes
Antibiotics
Esters | Guisinol | [
"Chemistry",
"Biology"
] | 51 | [
"Biotechnology products",
"Esters",
"Functional groups",
"Organic compounds",
"Antibiotics",
"Biocides",
"Organic compound stubs",
"Organic chemistry stubs"
] |
70,308,613 | https://en.wikipedia.org/wiki/Prosthecobacter%20fluviatilis | Prosthecobacter fluviatilis is a bacterium from the genus Prosthecobacter.
References
Verrucomicrobiota
Bacteria described in 2008 | Prosthecobacter fluviatilis | [
"Biology"
] | 37 | [
"Bacteria stubs",
"Bacteria"
] |
70,309,041 | https://en.wikipedia.org/wiki/Slab%20%28geometry%29 | In geometry, a slab is a region between two parallel lines in the Euclidean plane, or between two parallel planes in three-dimensional Euclidean space or between two hyperplanes in higher dimensions.
Set definition
A slab can also be defined as a set of points:
where is the normal vector of the planes and .
Or, if the slab is centered around the origin:
where is the thickness of the slab.
See also
Bounding slab
Convex polytope
Half-plane
Hyperplane
Prismatoid
Slab decomposition
Spherical shell
References
Elementary geometry
Geometric shapes | Slab (geometry) | [
"Mathematics"
] | 108 | [
"Geometric shapes",
"Mathematical objects",
"Elementary mathematics",
"Elementary geometry",
"Geometric objects",
"Geometry",
"Geometry stubs"
] |
70,311,302 | https://en.wikipedia.org/wiki/Diploma%20of%20the%20Verkhovna%20Rada%20of%20Ukraine | The Diploma of the Verkhovna Rada of Ukraine is an award of the Verkhovna Rada of Ukraine for significant contribution to any sphere of state life, outstanding socio-political activity, merits to the Ukrainian people in promoting and strengthening Ukraine as a democratic, social, legal state, implementation of rights and freedoms of citizens, development of democracy, parliamentarism and civil harmony in society, and finally, active participation in legislative activities.
Laureates
See also
Honorary Diploma of the Verkhovna Rada of Ukraine
References
Awards of the Verkhovna Rada of Ukraine
Laureates of the Diploma of the Verkhovna Rada of Ukraine
Badges
Ukrainian awards | Diploma of the Verkhovna Rada of Ukraine | [
"Mathematics"
] | 138 | [
"Symbols",
"Badges"
] |
70,312,163 | https://en.wikipedia.org/wiki/M.%20Grace%20Burke | Mary Grace Burke is an American materials scientist who is an emeritus professor at the University of Manchester. She was awarded the 2020 International Metallographic Society Henry Clifton Sorby Award and was the 2019-2023 President of the Royal Microscopical Society.
Early life and education
Burke was raised in Pittsburgh. She remained in Pittsburgh for undergraduate studies, during which she specialized in metallurgical engineering at the University of Pittsburgh. Burke attended Imperial College London, where she did her PhD research on stress corrosion cracking (SCC). Working under the supervision of P. R. Swann and F. J. Humphreys, Burke studied the mechanism of SCC of austenitic stainless steel. Burke was interested in the relationship between materials behavior and microstructure.
Research and career
After earning her doctorate, Burke returned to the United States, where she worked at the U.S. Steel Research Laboratory in Monroeville, Pennsylvania. She studied thermomechanical processing effects on microstructural evolution in steels, using analytical transmission electron microscopy. She also performed correlative TEM analyses in combination with atom probe field ion microscopy (APFIM).
Burke also studies irradiation embrittlement of the steels and alloys used in light water reactor systems. She joined the Westinghouse Science and Technology Center, where she studied a broad range materials and alloys for nuclear power systems. She transferred to the Bettis Atomic Power Laboratory, where she studied how microstructure impacted the performance of materials.
Burke joined the University of Manchester in England as a Professor of Materials Performance and Director of the Materials Performance Centre in 2011.
Awards and honors
1995 Elected Fellow of ASM International
2005 President of the Microscopy Society of America
2015 Elected Fellow of the Institute of Materials, Minerals and Mining
2018 MicroAnalysis Society President's Award
2018 Elected Fellow of The Microanalysis Society
2019 Elected President of the Royal Microscopical Society
2019 Elected Fellow of The Metals, Materials and Minerals Society (TMS)
2020 International Metallographic Society Henry Clifton Sorby Award
2021 Henri Coriou Award
References
Living people
Scientists from Pittsburgh
Alumni of Imperial College London
University of Pittsburgh alumni
Academics of the University of Manchester
Materials scientists and engineers
21st-century American scientists
21st-century American women scientists
Year of birth missing (living people) | M. Grace Burke | [
"Materials_science",
"Engineering"
] | 464 | [
"Materials scientists and engineers",
"Materials science"
] |
70,312,168 | https://en.wikipedia.org/wiki/VPNLab | VPNLab was a VPN service that catered to cyber criminals. The service was shut down by following a seizure Europol in January 2022.
History
VPNLab was created in 2008. The service advertised VPN servers in multiple countries and offered double encryption. The service was known for providing services to cyber criminals, specifically ransomware authors. The site accepted a variety of payments, including WebMoney and Bitcoin. The "DoubleVPN" service was offered at $129 a year. The owners advertised the website on the dark web.
Raid and shutdown
On January 17, 2022, Europol, along with other national law enforcement agencies seized VPNLab's domain. As of January 19, 2022, no arrests were made. Along with Europol, the FBI (United States), Central Directorate of the Judicial Police (France), and National Crime Agency (United Kingdom) were involved in the site raid.
References
Defunct websites
Internet services shut down by a legal challenge
Virtual private network services
Internet properties established in 2008 | VPNLab | [
"Technology"
] | 214 | [
"Computing stubs",
"Computer network stubs"
] |
70,312,418 | https://en.wikipedia.org/wiki/Honorary%20Diploma%20of%20the%20Verkhovna%20Rada%20of%20Ukraine | The Honorary Diploma of the Verkhovna Rada of Ukraine is an award of the Verkhovna Rada (parliament) of Ukraine for significant contribution to any sphere of life, outstanding socio-political activities, services to the Ukrainian people in promoting and strengthening Ukraine as a democratic, social, legal state, implementing measures to ensure rights and freedoms of citizens, development of democracy, parliamentarism and civil harmony in society, and active participation in legislative activities.
Laureates
See also
Diploma of the Verkhovna Rada of Ukraine
References
Awards of the Verkhovna Rada of Ukraine
Laureates of the Honorary Diploma of the Verkhovna Rada of Ukraine
Ukrainian awards
Badges | Honorary Diploma of the Verkhovna Rada of Ukraine | [
"Mathematics"
] | 141 | [
"Symbols",
"Badges"
] |
70,313,461 | https://en.wikipedia.org/wiki/EQ%20Tauri | EQ Tauri is a triple star system in the equatorial constellation of Taurus that includes a contact eclipsing binary. The system is too faint to be viewed with the naked eye, having a baseline apparent visual magnitude of 10.5. During the primary eclipse, the brightness of the system drops to magnitude 11.03, then to 10.97 during the secondary minimum. The secondary eclipse is total. Based on parallax measurements, it is located at a distance of approximately 730 light years from the Sun.
The star HV 6189 was identified as a short-period variable by H. Shapley and E. M. Hughes in 1940, then was more closely studied by Soviet astronomer V. P. Tsesevich in 1954. It was determined to be a W UMa-type variable and was noted for being located in the region of the Pleiades open cluster. An analysis of data from Tsesevich and subsequent observations by B. S. Whitney in 1972 suggested that the period is variable. His observations from Konkoly Observatory showed a period of . W. R. Benbow and R. L. Mutel built a light curve of the eclipsing variable in 1995 that displayed evidence of an active region on the stellar surface. Orbital period changes continued to be observed, and in 2002 T. Pribulla and M. Vanko suggested it is caused by a third body in the system. They modeled it as a low mass red dwarf with an orbital period of 50.2 years.
This is a shallow contact binary system, belonging to sub-type A of the W Ursae Majoris class. It has an orbital period of and a semimajor axis of 2.48 times the radius of the Sun. The orbit shows a cyclical change with a period of 22.7 years and an amplitude of 0.0058 days. A transit-like event was observed in 2010. The more massive component is a solar-type star with a deep convection zone that appears magnetically active with a significant coverage of star spots.
References
Further reading
Triple stars
W Ursae Majoris variables
Taurus (constellation)
BD+18 661
029260
021517
Tauri, SZ | EQ Tauri | [
"Astronomy"
] | 456 | [
"Taurus (constellation)",
"Constellations"
] |
70,313,832 | https://en.wikipedia.org/wiki/Lassar%20Cohn | Lassar Cohn, Lassar-Cohn or Ernst Lassar Cohn (6 September 1858 – 9 October 1922) was a Prussian chemist and professor at the University of Königsberg who wrote several influential textbooks on organic analysis including methods for the analysis of urine.
Cohn was born in the Jewish family of Jacob Marcus Cohen and Hanna Hewe in Hamburg. He studied at the Gymnasium in Königsberg before going the University of Heidelberg. He also studied at Bonn and Königsberg. After receiving a doctorate in 1880 and habilitation in 1888 he joined the University of Königsberg and became a professor in 1894. He worked for some time from 1897 at the Ludwig-Maximilians-University in Munich but returned to Königsberg in 1902. In 1907 he also began to work with the chemical industry. Cohn's major works included studies of organic compounds, tartaric acid and its esters, bile chemistry and the recycling of industrial wastes. He innovated methods for nitrogen measurement, saccharimetry, and urine analysis.
References
External links
Chemistry in Daily Life (1909)
A laboratory manual of organic chemistry (1895)
Application of some general reactions to investigations in organic chemistry (1904)
1858 births
1922 deaths
Biochemists
Scientists from Hamburg
German chemists | Lassar Cohn | [
"Chemistry",
"Biology"
] | 261 | [
"Biochemistry",
"Biochemists"
] |
71,753,376 | https://en.wikipedia.org/wiki/Coastal%20Swamp%20Oak%20Forest | Coastal Swamp Oak Forests, also known as Swamp Oak Floodplain Forests and Estuarine swamp oak forests, are scattered riparian forests found in southeastern Queensland to southeastern New South Wales, Australia that would predominantly feature Casuarina glauca (swamp oaks). They occur within the South Eastern Queensland, NSW North Coast, Sydney Basin, or South East Corner bioregions.
Geography
Only about 26% of their original extent remaining, Coastal Swamp Oak Forests generally occur on light or alluvial soil on coastal flats, floodplains, drainage lines, lake margins, wetlands and estuarine fringes where soils are at least at times saturated, marshy or overflowed. Some may occur on coastal dune swales or flats.
Having a dense to sparse tree layer, the community is mostly found as disjointed residue patches along the coast between Curtis Island (south-east Queensland), north of Gladstone, and Bermagui (southern New South Wales), up to 50 m above sea level (ASL) but usually less than 20 m ASL and they are usually within 30km of the coast, but in several areas, such as along tidal river catchments, the community can be present more than 100km inland.
Extent
Major presence include: around 350 ha on the Tweed lowlands; to a lesser degree than 650 ha on the lower Clarence floodplain; less than 400 ha on the lower Macleay floodplain; less than 3,200 ha in the Hunter Valley; less than 5,200 ha in the Sydney and South Coast region and less than 1,000 ha in the Eden region. The community's composition may alter from open forests to low woodlands, scrubs or reed lands with scattered trees.
Ecology
Although swamp oaks are the principal trees that occur in the canopy, there also exist many other species such as, Acmena smithii, Alphitonia excelsa, Melaleuca salicina, Cupaniopsis anacardioides, Glochidion ferdinandi, Parsonsia straminea and at times Melaleuca spp., where they shape a sub-canopy layer.
The saline understorey consists of Baumea juncea, Alexfloydia repens, Baumea juncea, Juncus kraussii, Phragmites australis, Selliera radicans, Cynodon dactylon, Phragmites australis, Parsonsia straminea, Geitonoplesium cymosum, Stephania japonica and Suaeda australis, with freshwater species being Blechnum indicum, Carex appressa, Gahnia clarkei, Centella asiatica, Oplismenus imbecillis, Commelina cyanea, Hypolepis muelleri, Persicaria decipiens, Lomandra longifolia, Microlaena stipoides and Viola banksii. The total canopy cover is least 10%.
Biodiversity
The animals that occupy the community also dwell in conterminous wetlands, grasslands, woodlands and forests. The animals include bats, possums, bandicoots, birds, frogs, turtles and other reptiles. Mammals include Cercartetus nanus, Myotis macropus, Phascogale tapoatafa, Pteropus poliocephalus, Syconycteris australis, Phascolarctos cinereus, Antechinus stuartii, Perameles nasuta, Potorous tridactylus, Pseudomys novaehollandiae and Rattus lutreolus.
Reptiles present are, Cyclodomorphus michaeli, Egernia mcpheei, Boiga irregularis, Hemiaspis signata, Hoplocephalus bitorquatus, Pseudechis porphyriacus, Tropidechis carinatus, Chelodina longicollis, Emydura macquarii, Elseya albagula, Elusor macrurus and Wollumbinia georgesi.
Plant communities
Various state vegetation mapping units contain the Coastal Swamp Oak Forest, and patches of it are likely to correspond with the Plant Community Types (PCT) listed in the table below:
See also
River-flat eucalypt forest
References
Endangered ecological communities
Geography of Sydney
Remnant urban bushland
Vegetation of Australia
Ecoregions of New South Wales
Ecoregions of Queensland
Sclerophyll forests
Casuarina | Coastal Swamp Oak Forest | [
"Environmental_science"
] | 921 | [
"Riparian zone",
"Hydrology"
] |
71,754,236 | https://en.wikipedia.org/wiki/CHIMERE%20chemistry-transport%20model | CHIMERE is a chemistry-transport model. It is a computer code that unites a set of equations representing the transport and the chemistry of atmospheric species making it possible to quantify the evolution of air masses and pollution plumes as a function of time on different scales (from urban to continental). Using meteorological inputs and emission fluxes, CHIMERE calculates three-dimensional concentrations of pollutants in the atmosphere. Due to the input data used, the number of equations that are solved and the physico-chemistry included in the model, CHIMERE is considered to be a mesoscale model, i.e. simulating the troposphere (from the surface to 20 hPa) for a horizontal resolution of 1 to 100 km and over study areas ranging from the city to the hemisphere.
Simulated pollutants
Atmospheric pollutants are gaseous molecules or particles present in the Earth's atmosphere and are considered to be in excess. Beyond a certain concentration threshold, their content can be toxic to the vegetation or to human health. These thresholds are different for each pollutant and are monitored hourly on surface-level atmosphere. CHIMERE simulates around a hundred gaseous and aerosol chemical species, including those monitored on a daily basis: ozone O3, nitrogen oxides NO and NO2, particulate matter PM, carbon monoxide CO and sulfur dioxide SO2.
Possible applications
This numerical model can have several applications:
analyze past pollution episodes, by comparing available measurements to model results: this allows not only to better understand the mechanics of a particular episode but also to highlight the weaknesses of the model and therefore to guide the path for future development.
make scenarios: in particular by simulating a period for the first time in realistic conditions, then by redoing the simulation by modifying the emissions for example. For this example, this type of exercise makes it possible to quantify the gain that a decline in emissions could have or, on the contrary, to estimate the damage in advance in a possible future where emissions keep increasing.
carry out air quality forecasts: this is done typically two to three days in advance and over a given region. The CHIMERE model is used by a large number of air quality monitoring agencies in Europe for this purpose. In France, it is notably the model implemented daily for pollution forecasts (as part of the “Air Quality and the Rational Use of Energy” law passed on the 30 September 1996) by AIRPARIF in the Paris region and Atmo Grand Est in the Grand Est region. In France on a national level, CHIMERE is the modeling tool implemented by INERIS for the PREVAIR air quality forecasting platform.
Basis of the model
The CHIMERE model necessitates three main phases: a data preparation phase (pre-processing) essential for a simulation, the model itself for calculating atmospheric concentrations and a results exploitation phase (post-processing). This principle is true for all digital tools of this type (see figure).
Phase 1 - pre-processing:
The preprocessing phase contains the preparation of the input information necessary for running a chemistry-transport model throughout its simulation (several days or weeks are calculated with a time step of a few seconds): meteorological fields and emissions (of different sources). Additional inputs are also prepared during this step, which represent the initial and boundary conditions (chemical concentrations) and land surface information (soil and surface types, vegetation).
Phase 2 - CHIMERE model
After reading all the input data, systems of stiff differential equations, including all chemical reactions included in the model (with species having from a few microseconds to several days of lifetime in the atmosphere) are integrated over time and space. At the same time, transport (advection and convection), turbulence, emissions (sources) and dry and wet deposition (sinks) are treated in the form of flows which will increase (in case of sources) or decrease (in case of sinks) the pollutant concentrations for each chemical species, cell by cell and minute by minute.
Phase 3 - Post-processing:
Post-processing allows to analyze the results of the simulation. Concentration fields at thousands of cell points and hour by hour often represent too much information to draw conclusions from directly. This step makes it possible to calculate scores (by comparing the results of the simulation to surface stations, by which we seek to quantify the precision of the simulations in relation to observations), synthetic maps (for example maximum ozone or particles over a day, average daily SO2 concentration, etc.).
Current research with the model
The CHIMERE model is under continuous development and a new version of the code is made available to users about once a year. If the regional modeling of gaseous species is relatively well represented at this point, there are still great uncertainties in the simulation of aerosols. Aerosols have different origins (anthropogenic and urban, fire combustion aerosols, or mineral aerosols) and different lifetimes, making modeling them correctly complex. Current research is revolving around impact of air quality on health, including design of models that can compute the exposure of the population to different pollutants but also to around the consideration of new species to monitor (such as pollen, which are highly allergenic). The latest version of the model includes so-called "on-line" effects. Until recently, this type of model was always in "off-line" mode; i.e. the meteorology was pre-calculated and then used to calculate the chemistry and transport of pollutants. In the latest v2020 version, feedback between meteorology and atmospheric chemistry have been implemented, making it possible to calculate the radiative impact of aerosols (direct effects) and cloud formation (indirect effects) more realistically.
Development and distribution of the model
The model is developed by researchers from the P.S.Laplace CNRS Institute (IPSL). The code is developed under the GNU GPL free software license and is available on a website, http://www.lmd.polytechnique.fr/chimere.
References
Air pollution in France
Computational chemistry | CHIMERE chemistry-transport model | [
"Chemistry"
] | 1,254 | [
"Theoretical chemistry",
"Computational chemistry"
] |
71,754,298 | https://en.wikipedia.org/wiki/Exsiccata | Exsiccata (Latin, gen. -ae, plur. -ae) is a work with "published, uniform, numbered set[s] of preserved specimens distributed with printed labels". Typically, exsiccatae are numbered collections of dried herbarium specimens or preserved biological samples published in several duplicate sets with a common theme or title, such as Lichenes Helvetici (see figure). Exsiccatae are regarded as scientific contributions of the editor(s) with characteristics from the library world (published booklets of scientific literature, with authors/ editors, titles, often published in serial publications like journals and magazines and in serial formats with fascicles) and features from the herbarium world (uniform and numbered collections of duplicate herbarium specimens). Exsiccatae works represent a special method of scholarly communication. The text in the printed matters/published booklets is basically a list of labels () with information on each single numbered exsiccatal unit. Extensions of the concept occur.
There are several comprehensive bibliographies and treatments on exsiccatae devoted to algae, bryophytes and lichens, lichens and fungi. A printed bibliography on works devoted to vascular plants is missing. The IndExs – Index of Exsiccatae online database closes the gap.
Early history
Exsiccatae are also known under the terms exsiccatal series, exsiccata(e) series, exsiccata(e) works, exsiccatae collections, sometimes exsiccati, exsiccate. Furthermore, the feminine noun term "exsiccata" (Latin, gen. -ae, plur. -ae) for exsiccata series is often not clearly distinguished from the neuter noun "exsiccatum" (Latin, gen. -i, plur. -a) which is used in general for a dried herbarium specimen. There exists also the Latin adjective "exsiccatus, -a, -um" meaning "dried" which is often part of a Latin title of an exsiccata, e.g. Lichenes exsiccati.
The oldest series known as an exsiccata is that of the German naturalist and pharmacist called Herbarium vivum recens collectum... It was distributed in 1732. The plant material and text information is for the education of physician, pharmacists and teachers.
With this goal, the system of exsiccatae is originated from herbarium books with images of plants and fungi, such as the Herbaria viva distributed in the 16th and 17th century, but now contained dried and pressed plant material. Series with scholarly and scientific focus followed few years later. One of that kind of series was published by the Swiss botanist Jakob Friedrich Ehrhart, a pupil of Carl Linnaeus, with the title Plantae cryptogamae Linn., quas in locis earum natalibus collegit et exsiccavit Fridericus Ehrhart. The first fascicle was delivered in 1785. As one of the first Jakob Friedrich Ehrhart promoted the selling of dried plants with several series, among others Arbores, frutices et suffrutices Linnaei quas in usum dendrophilorum collegit et exsiccavit Fr. Ehrhart and Calamariae, Gramina et Tripetaloideae Linnaei, quas in usum botanicophilorum collegit et exsiccavit Fr. Ehrhart.
The majority of the 2,300 known exsiccatae appeared in the 19th century. They are often specialised by a single organism group or geographical region. Two examples:
Alexander Braun, Gottlob Ludwig Rabenhorst and Ernst Stizenberger have distributed Die Characeen Europa's in getrockneten Exemplaren, unter Mitwirkung mehrerer Freunde der Botanik, gesammelt und herausgegeben von Prof. A. Braun, L. Rabenhorst und E. Stizenberger in 1878 and Thomas Drummond published Musci Americani; or, specimens of the mosses collected in British North America, and chiefly among the Rocky Mountains, during the Second Land Arctic Expedition under the command of Captain Franklin, R.N. by Thomas Drummond, Assistant Naturalist ... in 1828.
Some series are devoted to organisms of economical or medicinal relevance, and thus of interest for pharmacists, plant pathologists, veterinarians, people working in horticulture, agriculture and forestry. Felix von Thümen published some exsiccatal series of this kind, e.g., Herbarium mycologicum oeconomicum.
Relevance in science
Exsiccatae are well-known reference systems in collection-based life science and biodiversity research. Especially in early, large and widely distributed series like the Fungi Rhenani of Karl Wilhelm Gottlieb Leopold Fuckel, many taxonomic type specimens are among the 2,700 numbered specimen units, now labelled as isotypes or lectotypes.
In 2001, a web portal with underlying database called IndExs – Index of Exsiccatae was published with the goal of gathering and providing bibliographic information on all types of exsiccatae and exsiccata-like series. Currently more than 2,200 series with more than 1,300 editors are known. The editors are often well known as taxonomists. In the case that they published exsiccatae, the series are explicitly cited in Frans Stafleu and Richard Sumner Cowan's standard work Taxonomic Literature: A Selective Guide to Botanical Publications and Collections, with Dates, Commentaries, and Types (7 volumes) and in the 8 volumes of the supplement series with the first 6 co-authored by Erik Albert Mennega. How many issues (= sets) of an exsiccata is published and distributed is often unknown. In large institutional herbaria (see List of herbaria), the exsiccatae are often not kept in their original sets, but each single numbered specimen unit is inserted in the general collections and filed under the current taxon name, e.g. in M and in HUH (FH).
ICBN/ ICN articles and exsiccatae
In the 19th century with mid of 20th century, exsiccatae played an important role in botany, mycology and binomial nomenclature. A lot of taxa were described with diagnosis in exsiccatae or exsiccatal-like specimen series using printed labels and schedae booklets for effective publication of the names, see for example Iris camillae described by Alexander Alfonsovich Grossheim in the schedae of Plantae orientales exsiccatae. These printed matters are often so-called grey literature. In the Vienna rules (1906) of the ICBN, now International Code of Nomenclature for algae, fungi, and plants (ICN), exsiccatae and their printed matters were explicitly mentioned in the context of valid publication (Article 37). With 1953 (under the Stockholm Code) the printed matters accompanying exsiccatae must be distributed independently of the exsiccatae for effective publication (see, e.g., Vienna Code 2006, Article 30.4). The recent code (Shenzhen Code 2018) does only mention exsiccatae explicitly but gives two exsiccatae as examples for effective publication under Article 30.8, Note 2. This correlates with the minor role that current exsiccatae play today with around 70 series running.
Herbarium digitization initiatives
Approximately 10 million of the 350 million botanical specimens in the major herbaria belong to the 2,300 widely distributed exsiccatae and exsiccata-like series. The specimens are either included in the general collections of the major herbaria or kept there as separate fascicles (see Index Herbariorum). Thus, the series are explicitly addressed by joint advanced digitization projects of biodiversity collections like iDigBio. As a result, most of the iDigBio web portals have a section for accessing specimens of exsiccatae, like the portal of the Consortium of Midwest Herbaria.
Approaches to generate virtual herbaria are optimizing their label data capture with linking the specimen text information to standard abbreviations of the exsiccata series following (online) bibliographies and example label images for disambiguation purposes. Citizen science approaches for herbarium label digitization have instructions about how to recognize exsiccatae and how to mobilize this information in a structured manner. An example is the guideline of the BGBM Herbonauten.. In general, the collections management systems used at major herbaria are able to handle data on exsiccata series and single exsiccata specimens.
Similar as iDigBio the concept for complete digitization of German herbaria is including the mobilisation of this structured historical information using a standard reference list of editors, titles, abbreviations, publication dates and number ranges. This procedure will facilitate the discovery of duplicate exsiccata specimens in the various herbaria and avoid multiple typing of the same text information. The mobilisation of this data is regarded as an example for creating synergies between institutional herbaria during the digitization process.
Exsiccata-like series
Ideally, exsiccatae comprise dried plant or fungus material as a result of plant collecting, have a descriptive title, one or more editors (or alternatively an editing organisation), printed labels and the single dried specimens have printed taxon names, locality information and exsiccatal numbers and are distributed in sets/fascicles. The publication size vary depending on the work from very few until up to 70 duplicate specimens per numbered unit. Over time, with the changing goals in the wide field of organismic botany and mycology there were deviations in all aspects. There are exsiccata-like series distributing preserved natural objects other than dried herbarium material. Examples are glass slides with microorganisms, see Diatomacearum species typicae edited by Hamilton Lanphere Smith, and slides of wood, see American Woods edited by Romeyn Beck Hough.
Especially within the 19th century a number of exsiccata-like series and duplicate specimen collections which superficially resemble exsiccatae are known: Some are without descriptive titles (instead they may have an organization as header), some without mentioned editors, others with labels that are in parts handwritten with handwritten numbers, and series without sequential numbers as well as series whose sets are not uniform and schedae which are not published as independent schedae work. Some works as that of William Gardiner with the title Twenty lessons on British Mosses; first steps to a knowledge of that beautiful tribe of plants ... illustrated with specimens with mounted herbarium specimens are primarily for educational purposes. This is also the case with the series Educational collections of Australian plants, edited by Ferdinand von Mueller. These works are regularly treated as library objects.
The 19th century saw the increase of the trade and the exchange with plant material: More than 100 societies for plant exchange purposes, mostly with non-commercial goals were founded, so-called plant exchange organizations, which build networks of citizen science to exchange plant material among their individual, private members. They were busy announcing new material, e.g., in scientific journals like Flora (Regensburg). Some of them distributed specimen series with characteristic printed labels superficially resembling exsiccatae, mostly with anonymous editors. An example is the Société Rochelaise pour l'échange des plantes françaises, starting in 1880, with around 15 specimen series. In addition to the plant exchange organisations described above, there were learned societies which, among other activities, published and distributed exsiccata-like collections of specimens. The Broterian Society with Flora Lusitanica (Soc. Brot. 1. anno) and its annual follow-up collections is a known example.
One of the well-known plant exchange organizations/ associations that existed more than a hundred years was the Société Française pour l'échange des plantes vasculaires, from 1911 to 2015. This organisation developed a large network of plant collectors worldwide, elaborated guidelines for plant collectors and distributed a number of exsiccata-like series, partly numbered, with printed labelsand distributed booklets. The last exsiccata-like series edited by the Société pour l'Échange des Plantes vasculaires de l'Europe et du Bassin méditerranéen et correspondant finally distributed 20,000 specimen units of vascular plants and started in 1947. The last secretary and in this function editor of the series was .
Few organizations had business models for selling exsiccatae and exsiccatae-like series. An example is the early Unio Itineraria, a society, which financially supported the scientific voyages of Georg Wilhelm Schimper and distributed series with printed labels like Schimper, Unio Itineraria 1835, and others. There were also individuals starting as plant collectors and later switching on dealing with exsiccata-like series. A famous example is Ignaz Dörfler who earned a living with this kind of trade for more than twenty years from 1894 until 1915. Some modern definitions of the term exsiccata reflect the purpose of sale and subscription in delivering exsiccatae, e.g. that in A Grammatical Dictionary of Botanical Latin. The recipients and buyers were private plant collectors, as well as learned societies and institutional herbaria. For more than two decades (1908-1932) there existed the journal Herbarium. Organ zur Förderung des Austausches wissenschaftlicher Exsiccatensammlungen Band I + II, no. 1-86 published by Theodor Oswald Weigel, Leipzig, who organised the sale of exsiccatae and exsiccata-like series in a professional manner.
Some individual historical collections of mounted plants (herbaria) were bounded as splendid book volumes. This kind of unique herbaria might
superficially resemble exsiccatae and were offered for purchase to single academic societies and princely courts as for example Giorgio Jan did at the beginning of the 19th century. In few cases the term exsiccata is used for characterizing botanical art works bounded as books, which contain decorative assortments of pressed plant specimens mounted to the pages, usually arranged in a theme.
References
Herbaria
Botany
Lichenology
Bryology
Mycology
History of mycology
Phycology
History of botany
Botanical literature | Exsiccata | [
"Biology"
] | 3,009 | [
"Algae",
"Plants",
"Mycology",
"Phycology",
"Botany",
"Lichenology"
] |
71,754,942 | https://en.wikipedia.org/wiki/Bothriodontinae | The bothriodontines are a paraphyletic assemblage of anthracotheres that originated from Eurasia in the late middle Eocene (Bartonian). The group can be distinguished from other anthracothere lineages by their upper molars having a mesostyle occupied by a transverse valley, selenodont cusps, a ventrally concave symphysis, elongated muzzles, and a diastema between the canine and first premolar tooth. During their evolution, the bothriodontines evolved from small basal forms such as Qatraniodon into larger taxa such as Libycosaurus and Merycopotamus. In some genera, the snouts became even more elongated and teeth specialized in a folivorous diet (e.g., Bothriodon, Aepinacodon), while others like Merycopotamus developed wide, heavy, and shallow muzzles with teeth more adapted for grazing.
References
Anthracotheres
Mammal subfamilies
Eocene first appearances
Paraphyletic groups | Bothriodontinae | [
"Biology"
] | 226 | [
"Phylogenetics",
"Paraphyletic groups"
] |
71,756,353 | https://en.wikipedia.org/wiki/Boeing%208C | The Boeing 8C was a gas turbine that was tested in a Ford Thunderbird. The turbine was capable at 175hp and required exhaust pipes to be installed at the front out the side. It was developed around August 1955 to March 1956 after the Ford Thunderbird was released to the public. However, the project remained a secret until 2022.
See also
List of aircraft engines
References
Airplane powered car
1950s turboshaft engines
Aircraft auxiliary power units
Gas turbines
Centrifugal-flow turbojet engines | Boeing 8C | [
"Technology"
] | 100 | [
"Engines",
"Gas turbines"
] |
71,756,479 | https://en.wikipedia.org/wiki/EUICC | eUICC (embedded UICC) refers to the architectural standards published by the GSM Association (GSMA) or implementations of those standard for eSIM, a device used to securely store one or more SIM card profiles, which are the unique identifiers and cryptographic keys used by cellular network service providers to uniquely identify and securely connect to mobile network devices. Applications of eUICC are found in mobile network devices (cell phones, tablets, portable computers, security controllers, medical devices, etc.) that use GSM cellular network eSIM technology.
Standards
The core standards that define eUICC are published by the GSM Association in two topical areas.
Consumer and IOT
Core standards for implementing eSIM on mobile devices include the following articles:
eSIM Architecture Specification
eSIM IoT Architecture and Requirement Specification
SGP 22 Remote Sim Provisioning(RSP) Architecture for consumer Devices
Machine to Machine (M2M)
GSMA publishes standards for machine-to-machine (M2M) third-party provisioning of eSIM which includes the following articles:
SGP.01 M2M eSIM Architecture v4.2
SGP.02 eSIM Technical Specifications V4.2.1
Implementation
eUICC can refer to any implementation or application of the eUICC standards in an eSIM device. Each implementation of eUICC includes software code, a processor to emulate the software, non-volatile memory used to store the unique identifiers and cryptographic keys that are part of a SIM profile, and a bus interface to communicate the SIM profile to the mobile device. eUICC standards specify that only one eUICC security controller (ECASD) may be implemented in an eSIM, but the eSIM may store multiple SIM profiles.
EID
GSMA standards define EID as "eUICC Identifier". Some developers / implementers have referred to this using the descriptive term "eSIM identifier", which summarizes the function of an eUICC Identifier. Some third parties have joined this acronym with the term "electronic identity document", which is a general concept of any identifier stored or presented in electronic format.
References
Architecture | EUICC | [
"Engineering"
] | 446 | [
"Construction",
"Architecture"
] |
71,756,929 | https://en.wikipedia.org/wiki/B%C3%A9n%C3%A9dicte%20Cuenot | Bénédicte Cuenot is a French engineer specializing in the numerical simulation of combustion and related phenomena, including turbulent flow, the flow of plasma, and heat transfer. Her software has been used to investigate the emission of pollutants and other products of combustion, non-carbon-based fuels including hydrogen, ammonia, and metal powders, the start and end of combustion, and the ability of combustion chambers to stand up under use. She heads the combustion research group at the European Centre for Research and Advanced Training in Scientific Computation (CERFACS) in Toulouse, and holds a professorship in mechanical engineering at Eindhoven University of Technology in the Netherlands.
Education and career
Cuenot studied engineering at the École Centrale Paris, earning an engineering degree and master's degree in 1990. She completed a doctorate in 1995, with the thesis Étude asymptotique et numérique de la structure des flammes de diffusion laminaires et turbulentes [Asymptotic and numerical study of the structure of laminar and turbulent diffusion flames] supervised by Thierry Poinsot at the National Polytechnic Institute of Toulouse. She earned a habilitation in 2000.
After becoming head of combustion research at CERFACS, in 2021 she added a part-time affiliation as professor at Eindhoven University of Technology, where she is affiliated with the group of Jeroen A. van Oijen in the department of mechanical engineering.
Recognition
Cuenot was elected to the inaugural 2018 class of Fellows of The Combustion Institute, "for excellent advances in the modelling and simulation of turbulent flames in complex, multi-physics environments".
References
External links
Year of birth missing (living people)
Living people
French engineers
Academic staff of the Eindhoven University of Technology
Fellows of the Combustion Institute
20th-century French women engineers
21st-century French women engineers
20th-century French engineers
21st-century French engineers | Bénédicte Cuenot | [
"Chemistry"
] | 384 | [
"Fellows of the Combustion Institute",
"Combustion"
] |
71,757,009 | https://en.wikipedia.org/wiki/HD%20183552 | HD 183552, also known as HR 7411, is a probable spectroscopic binary located in the southern constellation Telescopium. The system has a combined apparent magnitude of 5.74, allowing it to be faintly visible to the naked eye. Based on parallax measurements from the Gaia spacecraft, it is estimated to be 337 light years distant. The value is horribly constrained, but it appears to receding with a radial velocity of .
This object is an Am star with a spectral classification of kA6hF2mF2 (II), an evolved F-type star having the calcium K-line of an A6 star plus the hydrogen and metallic lines of an F2 star. Its current mass is and is estimated to be 733 million years old, having completed 83.1% of its main sequence lifetime. It has expanded to 4.7 times the radius of the Sun and now radiates 45 times the luminosity of the Sun from its photosphere at an effective temperature of .
References
Spectroscopic binaries
Am stars
F-type giants
Telescopium
Telescopium, 62
183552
7411
096141
PD-53 09585 | HD 183552 | [
"Astronomy"
] | 249 | [
"Telescopium",
"Constellations"
] |
71,758,492 | https://en.wikipedia.org/wiki/River-flat%20eucalypt%20forest | The River-flat eucalypt forest or Coastal floodplain eucalypt forest is a critically endangered threatened ecological community that is primarily found in southeastern Australia, from southeastern Queensland, through New South Wales, to eastern Victoria, on alluvial soils of the coastal floodplains.
The name chiefly refers to its riparian and floodplain landscape location and the predominant tree canopy being Eucalyptus, Angophora and/or Corymbia, which may exceed 40 m in height.
Geography
Less than 30% of its original range remaining, the community is found within the following bioregions: South East Corner (SEC), Sydney Basin (SYB), NSW North Coast (NNC), and South East Queensland (SEQ). It may also occur in warm temperate areas from east of Sale, Victoria, north to the Great Lakes on the New South Wales Mid North Coast to the south of Gladstone on the eastern coast of Australia. The community is on Quaternary alluvial soils, which may be soaked, waterlogged or overflowed, which include the riparian zones close to rivers and creeks, floodplain and associated depressions.
Flora
Varying from tall open forests to woodlands, the community is dominated by Angophora floribunda, Angophora subvelutina, Eucalyptus amplifolia and Eucalyptus tereticornis. In the south, more temperate species are present such as, Eucalyptus baueriana, Eucalyptus bosistoana, Eucalyptus botryoides, Eucalyptus elata, Eucalyptus longifolia, Eucalyptus ovata and Eucalyptus viminalis.
Non-eucalypts include Melaleuca spp, Allocasuarina littoralis, Elaeocarpus reticulatus, Casuarina cunninghamiana, Casuarina glauca, Glochidion ferdinandi, Lophostemon suaveolens, Alphitonia excelsa and Allocasuarina torulosa. Shrubs include Acacia floribunda, Prostanthera lasianthos, Breynia oblongifolia, Bursaria spinosa, Goodenia ovata, Pittosporum revolutum and Plectranthus parviflorus, in addition to scramblers, forbs and vines.
Fauna
Mammals include Pseudocheirus peregrinus, Pteropus poliocephalus, Phascogale tapoatafa, Trichosurus vulpecula, Acrobates pygmaeus, Petaurus australis, Petaurus breviceps, Petaurus norfolcensis, Petauroides volans and Cercartetus nanus. Birds include Haliastur sphenurus, Haliastur indus, Haliaeetus leucogaster, Pandion haliaetus and Erythrotriorchis radiatus.
See also
Coastal Swamp Oak Forest
References
Endangered ecological communities
Geography of Sydney
Remnant urban bushland
Vegetation of Australia
Ecoregions of New South Wales
Environment of Queensland
Sclerophyll forests
Biogeography of Victoria (state) | River-flat eucalypt forest | [
"Environmental_science"
] | 628 | [
"Riparian zone",
"Hydrology"
] |
71,759,039 | https://en.wikipedia.org/wiki/Microbial%20electrochemical%20technologies | Microbial electrochemical technologies (METs) use microorganisms as electrochemical catalyst, merging the microbial metabolism with electrochemical processes for the production of bioelectricity, biofuels, H2 and other valuable chemicals. Microbial fuel cells (MFC) and microbial electrolysis cells (MEC) are prominent examples of METs. While MFC is used to generate electricity from organic matter typically associated with wastewater treatment, MEC use electricity to drive chemical reactions such as the production of H2 or methane. Recently, microbial electrosynthesis cells (MES) have also emerged as a promising MET, where valuable chemicals can be produced in the cathode compartment. Other MET applications include microbial remediation cell, microbial desalination cell, microbial solar cell, microbial chemical cell, etc.,.
History
The use of microbial cells to produce electricity was perceived by M.C. Potter in 1911 with the finding that "The disintegration of organic compounds by microorganisms is accompanied by the liberation of electrical energy". A noteworthy addition in MFC research was made by B. Cohen in 1931, when microbial half fuel cells stack connected in series was created, capable of producing over 35 V with a current of 0.2 mA. Two breakthroughs were made in the late 1980s when two of the first known bacteria capable of transporting electron from the cell interior to the extracellular metal oxides without artificial redox mediators: Shewanella (formerly Alteromonas) oneidensis MR-1 and Geobacter sulfurreducens PCA were isolated. In late 90s, Kim et al. showed that the Fe(III)-reducing bacterium, S. oneidensis MR-1 was electrochemically active and can generate electricity in a MFC without any added electron mediators. These findings set basis for the development of electromicrobiology, and the field of MFC started. However, due to low power generation, it was also doubtful whether the MFC can be practical application on wastewater organics reduction. This view was changed when it was established that domestic wastewater could be treated to practical limits while simultaneously producing power. Furthermore, power densities two orders of magnitude higher was demonstrated in an MFC using glucose, without the need for exogenous chemical mediators. Building upon these works, a race to develop practical applications of MFCs initiated to emerge at a very fast pace, with the major goals being development of a large scale technology for the treatment of domestic, industrial, and other types of wastewaters.
In 2004, extracellular electron uptake (EEU) from cathodes to microbes (Geobacter spp.) was established with attached biofilm, where fumarate was reduced to succinate. This reverse reaction for electron transport generated the research field of MES. In 2010, Nevin et al. discovered that the acetogenic microorganism Sporomusa ovata can convert CO2 to acetic acid in MES cells by uptaking electrons from the cathode electrode. In the next years, also due to the growing concerns on greenhouse gas emissions, the field of CO2 bioelectroconversion in MES cell flourished. Several autotrophic microorganisms showed ability of capturing electrons from the cathode, either directly or through mediators. Besides specific microbial species, it was shown that CO2 reducing communities can be enriched in MES cells from inoculum sources such as sewage sludge, digester sludge or marine/river sediments. In the following decade, technical improvements led to an increase of acetate production rate from few to hundreds g/m2cathode/d. MES cells demonstrated also a promising technology for converting CO2 into biomethane, with production rates up to 200 L CH4/m2cathode/d. Furthermore, the MES scope was expanded to target more valuable products, including ethanol and caproate.
Principles
Microbial extracellular electron transfer
There are various mechanisms for bacteria to electrons with an electrode. These include a "direct" process, where redox components located on the cell surface, that can be multiheme cytochromes or nanofilaments, contact directly with the solid surfaces (Figure 1A, C and D), and an "indirect" process that is mediated by soluble redox mediators that cyclically shuttle electrons between cells and electrodes [28-30] (Figure 1B). Electron shuttles can be humic substances that are not produced by the cells, or secondary metabolites that are produced by the organisms including phenazines [32, 33] and flavins [34, 35]. In addition, some primary metabolites of bacteria, such as sulphur species and H2, can convey electrons towards extracellular electron acceptors. In addition to heme cofactors in multiheme cytochromes, flavin mononucleotide also were shown to enhance the rate of electron transfer in some outer membrane cytochrome as redox cofactors [27]. Because electrons are transferred from the interior to the exterior of microbial cells across the cellular membrane during EET, ions with positive charge need to simultaneously move in the same direction as the electron flow to maintain charge neutrality (Figure 1A).
Bioelectrochemical systems (principles, components, configurations)
A bioelectrochemical system (BES) is the device used in METs. A classic BES such as the MFC is typically composed of two sections (Figure 2): An anodic and a cathodic section separated by a selectively permeable, proton/cation exchange membrane or a salt bridge. In a MFC, the anodic section contains microbes that work as biocatalysts under anaerobic conditions in the anolyte, where the cathodic section contains the electron acceptor (e.g. oxygen). Electrons generated from the oxidation of organic compounds are conveyed to the anode. Electrons produced by the microbes are transferred to the anode directly via 'nanowires' or outer-membrane proteins, or indirectly using electron shuttling agents. These electrons reach the cathode across an external circuit and for every electron conducted, protons react at the cathode for completing the reaction and sustaining the electric current
.There are numerous types of BES reactors but broadly they all share the same operating principles. Various designs and configurations have been established to optimize the assembly of the three basic elements (anode, cathode and separator) in a functioning system. The performance of BESs is significantly changed with their design. Table 1. shows a summary of the major BES components and associated materials for their construction.
Table 1. Major components of MFC
Applications
Energy recovery and generation
Wastewater treatment with MFC
It is well-known that pumping, aeration, and solids handling are the major energy consuming process in wastewater treatments. Aeration alone can account for 50% of the operation costs at a typical wastewater treatment plant. Eliminating these costs can save a large amount of energy. MFCs in wastewater treatment, besides electricity generation, also help in energy savings linked to these mentioned processes which add a great advantage. The MFC process is an anaerobic process and sludge production for an anaerobic process is approximately 1/5 of that for an aerobic process. Thus, using MFCs could reduce solids production at a wastewater treatment plant, ultimately reducing significant operating costs for solids handling. Moreover, this technology has seen a nearly exponential increase in power production from the start of this century. This evolution echoes a mounting appreciation by engineers that this technology is ready to emerge as practical applications and associated technologies will be in limelight very soon.
The treatment of wastewater by MFC technologies is a promising and yet unique methodology as the process of wastewater treatment can become an approach of producing energy in the form of electricity, rather than energy expenditure. MFCs were used for the determination of lactate in water by K.I.M. and coworkers, and later showed that electricity production in an MFC could be sustained by starch using an industrial wastewater. A great variety of substrates have been used in MFCs for electricity production varying from pure compounds to complex mixtures of organic matter present in wastewater. The application of MFC for biotreatment of wastewater has also recorded effective conversion of organic matter in wastewater into electricity with about 40-90% COD and BOD reduction. Obviously, the energy that could be captured from wastewater is not enough to power a city, but it could be large enough to run a treatment plant. With the continuous advances, bagging this power could lead to energy sustainability of the wastewater infrastructure.
Benthic MFC
Benthic MFCs generate power through the microbial oxidation of organic substrates in anoxic marine sediments coupled to reduction of oxygen in the overlying water column. Electrons are generated from the metabolism of the naturally occurring microorganism in the various sediments. As such, benthic MFCs do not require the addition of any exogenous microorganisms or electron shuttles. The weather buoys obtained their entire power from the benthic MFC allowing them to operate continuously and independently from the need to replace batteries. Benthic MFCs can be operated for several years with no decrease in power output. The researchers estimated that a benthic MFC could provide power indefinitely at the same power levels and the same cost as a deep-sea power and light enclosed lead acid battery could deliver for one year.
Nutrients recovery
Nitrogen and phosphorus are considered as major pollutants in the wastewater whose removal and recovery are required for sustainable treatment systems. Nitrogen is conventionally removed by biological nitrification and denitrification processes which involves a very high energy and cost in wastewater treatment. BESs has a good potential for the recovery of ammonium nitrogen with good profits from waste streams rich in nitrogen such as urine, swine liquor, digester liquor and landfill leachate, etc. Phosphorus from the wastewaters is conventionally recovered as polyphosphate granules, Fe-P or struvite by bacteria. Cusick et al. achieved struvite production in a BES by employing single-chamber MEC, where up to 40% soluble phosphate was recovered by struvite precipitation at a rate of 0.3–0.9 g/m2/h. Other phosphorus recovery in BES involved exchange of hydroxide ions generated by the cathode reaction with phosphate ions from wastewater which resulted in removing 52.4 ± 9.8% of phosphate.
Microbial Electrochemical Remediation
BESs are known for both the oxidation and reduction-based processes for remediation of underground contaminants. In comparison to conventional biological treatment or chemical processes, BESs employ a single or multiple electrodes which are not closed reactors for pollutants' remediation. Solid electrodes in this system work as non-exhaustible electron acceptors/donors for stimulating microbial transformation of pollutants into non-toxic or less toxic forms. For example, enhancing the biodegradation of toxins with concomitant bioelectricity can be production. The complex petroleum organics, such as BTEX complexes (benzene, toluene, xylenes, and ethylbenzenes, etc.) can be bioremediated using BES systems. Morris et al reported that diesel (C8–C25) degradation was improved by 164% by introducing electrodes without power input. Investigations on biodiesel, phenol, total petroleum hydrocarbons, polycyclic aromatic hydrocarbons (PAHs), 1,2-dichloroethane, pyridine, etc., have been also stated, validating BES can be used as a practical technology for degrading petroleum hydrocarbon with simultaneous current generation. Chlorinated solvents like trichloroethene and tetrachloroethene, known for high toxicity or carcinogenic nature have been reported to degrade by using negatively polarized solid-state electrode which donate electrons with and without electron shuttles. The removal of nitrate, a common groundwater contaminant, have also been demonstrated either alone {Cecconet, 2018 #9} or in combination with other co-contaminants such as arsenite. In comparison to traditional denitrification which involves heterotrophic denitrifying bacteria, denitrification by BES involves autotrophic denitrifying bacteria which have the electrons uptake ability from the electrodes. Consequently, biocathodes in BES have been developed for denitrification which results in an efficient reduction of nitrate/nitrite at low energy costs in either groundwater and wastewater. In other studies, reduction of perchlorate, Cr(VI), Cu(II), and radioactive uranium have also been achieved in BESs with cathode as electron donors. The major benefit associated with the use of a solid electrodes as an electron donor instead of soluble electron donor is the reduction of contaminant (e.g., U(VI) to U(IV)) which is a stable precipitate at the electrode. Not only groundwater but also soil bioremediation have been explored using BES. For example, it has been demonstrated successful cleaning of herbicides and antibiotics in soil (Ref).
Microbial electrochemical production of chemicals
MES, a type of BES, can employ electricity for driving the synthesis of fuels and high value chemicals by employing microbes as cathodic catalysts which also results in the treatment of waste streams (Fig. 3). The dual benefits associated with this system are carbon sequestration and value added chemicals production. A wide range of valuable compounds have been produced by MES, such as H2, acetate, CH4, ethanol, butanol, H2O2, etc. The product spectrum in MES is largely governed by biocathodes materials (carbon- or metal-based), microorganisms involved, reduction potentials, and redox mediators activity, and operation conditions including pH, temperature and pressure. Potentials between -0.6 and -1.0 V vs SHE are typically applied to MES inoculated with mixed cultures to ensure production of hydrogen at the cathode, which is then uptake by acetogenic and methanogenic microorganisms to reduce CO2. CO2 reduction at less negative potentials, even above the theoretical potential of -0.4 V vs SHE, ha been demonstrated for specific microorganisms such as Sporomusa, although is still debated whether this it to be attributed to direct electron uptake from the cathode or to favorable thermodynamics at the electrode surface. Most studies on MES has been performed under ambient (around 20 °C) or mesophilic (around 35 °C), but the process was demonstrated feasible under thermophilic conditions (50-70 °C). Neutral or slightly acidic pH (5.5-7.0) was shown optimal for CO2 conversion to acetic acid, although lower pH, or use of inhibitors such as bromoethane sulphonic acid (BESA), is required to avoid the onset of methanogenesis. The chemical compounds obtained from MES can be used as precursors for the production of downstream industrial products such as polymeric products, diesel or kerosene resembling products, plasticizers, and as lubricating agents in many industries.
Figure. 3. Schematics of MES showing treatment of waste streams and formation of high value products.
Many organic compounds such as acetate, butyrate, and lactate, largely exists in effluents of wastewater plants and fermentation units. These organics are valued products, but due to their low concentrations, extraction is not a cost-effective option. Therefore, MES has been employed for the conversion of these short-chain carboxylic acids to longer chain acids and other useful products. Although higher value compounds can be obtained from low resource cost feeds, studies are required to compare if controlling the redox potential and supplying current to cathodes is economically feasible in comparison to current technologies. Nevertheless, further improvements in this technology platform can help in overcoming many of the fundamental challenges of a future bioeconomy.
Microbial electrolysis for production of H2
When used for hydrogen production, the MEC needs to be supplemented by an external power source to get over the energy barrier of turning all organic material into carbon dioxide and hydrogen gas. A standard MFC is converted to a hydrogen producing MEC by supplementing > 0.14 V. Hydrogen bubbles form at the cathode and are collected to be used as fuel source. Although electricity is used instead of generated as in normal MFCs, this method of producing hydrogen is efficient because more than 90% of the protons and electrons generated by the bacteria at the anode are turned into hydrogen gas. Hydrogen can be accumulated and stored for later usage to overcome the inherent low power feature of the MFCs.
Microbial electrochemical biogas upgrading to CH4
The concept of microbial electrochemical reduction involves the conversion of carbon dioxide which is the non-energy-rich component of the biogas produced in the anaerobic digester to the energy-rich component of methane. This reduction is possible through the chemical reaction between carbon dioxide, protons and electrons (from electricity) in a MES. This is otherwise known as Power-to-Gas technology, which allows electrochemical units to act as carbon sinks for industrial waste and more importantly industrial CO2 emissions. Power-to-Gas technology potentially generates biogas with a similar grade to natural gas without the need to remove CO2 using expensive techniques, such as amine scrubbing or pressure swing adsorption.
Water desalination
Desalination of sea water and brackish water used for drinking water has always presented significant problems because of the amount of energy required to remove the dissolved salts from the water. By using an adapted MFC, this process could proceed with no external electrical energy input. When adding a third chamber in between the two electrodes of a standard MFC and filling it with sea water, the cell's positive and negative electrodes attract the positive and negative salt ions, respectively, and the salt can be filtered out from the sea water using semi-permeable membranes. Salt removal efficiencies of up to 90% have been recorded in laboratory work.
Biosensors
MFCs have applications in monitoring and control of biological waste treatment unit due to their correlation of coulombic yield of MFC and strength of organic matter in wastewater which serves as readings for biosensors. Systems based on the microorganism Shewanella show promise as sensors for quantifying the biological oxygen demand in sewage. This concept can readily be expanded to detect other compounds that can act as electron donors for electricity production, such as hydrogen or aromatic contaminants. Also, such sensors could be extremely useful as indicators of toxicants in rivers, at the entrance of wastewater treatment plants, to detect pollution or illegal dumping, or to perform research on polluted sites.
With the development of micro-electronics and related disciplines the power requirement for electronic devices has drastically reduced. MFCs can run low-power sensors that collect data from remote areas. Anaerobic bacteria that naturally grow in the sediment produce the small current that can be used to charge a capacitor to store energy for the sensor. One major advantage of using a MFC in remote sensing rather than a traditional battery is that the bacteria reproduce, giving the MFC a significantly longer lifetime than traditional batteries. The sensor can thus be left alone in a remote area for many years without maintenance. Extensive research toward developing reliable MFCs to this effect, is focused mostly on selecting suitable organic and inorganic substances that could be used as sources of energy. Microbial current production is also applicable to bioelectrochemical sensors for drug screening to biofilm or wastewater-based epidemiology.
See also
Geobacter
Bacterial nanowires
Exoelectrogen
Bioelectrochemical reactor
References
Biophysics | Microbial electrochemical technologies | [
"Physics",
"Biology"
] | 4,179 | [
"Applied and interdisciplinary physics",
"Biophysics"
] |
71,759,775 | https://en.wikipedia.org/wiki/Rhopalophora%20clavispora | Rhopalophora () is a genus of lichen-like fungus in the family Dactylosporaceae. It contains the sole species R. clavispora, previously belonging to the genus Phialophora but redescribed in 2016 to compose this monotypic genus.
Description
Members of Rhopalophora are lignicolous fungi of mycelium made of hyaline or pigmented hyphae that are occasionally monilioid. They have no conidiomata. Their conidiophores are pale brown in color, unbranched, macronematous (i.e. morphologically different from vegetative hyphae), often reduced to phialides generated directly from undifferentiated hyphae, sometimes with percurrent regeneration. Phialides are light brown in color, paler towards the tip, integrated, subcylindrical and sometimes with sympodial proliferation, tapering toward the collarette. The conidia are hyaline, aseptate, clavate, truncate at the base, and arranged in chains or heads.
The sexual morph of this genus is unknown.
Taxonomy
The genus Rhopalophora was described in 2016 by Martina Réblová, Wendy A. Untereiner & Walter Gams to accommodate the species R. clavispora, which was initially described in 1976 by the same Walter Gams as a member of Phialophora. The separation was due to a phylogenetic analysis revealing Phialophora clavispora to be more related to other fungal members of Sclerococcaceae than to Phialophora.
References
Lecanorales
Fungi described in 1976
Fungus species | Rhopalophora clavispora | [
"Biology"
] | 358 | [
"Fungi",
"Fungus species"
] |
71,762,787 | https://en.wikipedia.org/wiki/GM%20Whirlfire%20engine | The GM Whirlfire gas turbine engines were developed in the 1950s by the research division of General Motors Corporation and fitted to concept vehicles, including the Firebird concept cars, Turbo-Cruiser buses, and Turbo-Titan trucks through the 1960s. They are free-turbine turboshaft machines with two spools: one compressor/gasifier turboshaft and one power/output turboshaft sharing a common axis without a mechanical coupling between them. Fuel consumption of the first-generation GT-300 was high compared to piston engines, so thermal wheel regenerators were added to the second-generation GT-304, cutting consumption by approximately .
Initially, the engines were built by GM Research, but starting with the third generation GT-305, the Allison Engine division took over responsibility for commercializing gas turbine technology. This division, later merged with Detroit Diesel and renamed Detroit Diesel Allison, would produce approximately one hundred of the final design GT-404 engines, which incorporated ceramic components. Cost, driven by exotic turbine alloys and materials, and fuel consumption proved to be insoluble issues compared to conventional piston engines and further development of gas turbine engines at General Motors was discontinued in the early 1980s.
Design
Because the Whirlfire engines are free-turbine machines, maximum torque is developed when the output shaft is stalled (not turning), and is approximately double the torque developed at full power output. In addition, the lowest fuel consumption is achieved at full power.
Gas path
In the third-generation GT/GMT-305, the air intake is arranged axially with the turboshafts, which share a common horizontal axis. The single-stage rotary compressor draws air at atmospheric conditions through the intake and expels compressed air out radially into the side compartments, where the rotating drum-shaped regenerators preheat the compressed air using heat extracted from the exhaust gases. The compressed air is channeled through the combustors, where it is mixed with fuel and burned, and the resulting combustion gases are expanded through first the gasifier turbine, which is on the same shaft and is used to drive the rotary compressor, then through the power turbine, which is on the output shaft.
At the gasifier turbine inlet, the design temperature is . For the GMT-305, the rotary speed of the gasifier/compressor shaft is 33,000 RPM, while the power shaft turns at 24,000 RPM at full power; the power shaft speed is stepped down to 3,500 RPM through reduction gearing at the output to make it compatible with automotive components. A governor allows the output shaft to turn up to 4,500 RPM. An accessory shaft is driven from the gasifier/compressor shaft for engine ancillaries, including a gear-type lubrication oil pump.
Regeneration
Initially, the first engines developed (GT-300 and 302) did not have a regenerator, but adding regeneration to recapture heat from the exhaust gases was found to reduce fuel consumption by for the second-generation GT-304, so subsequent generations of GM Whirlfire gas turbine engines incorporated a regenerator.
For the GT/GMT-305, two drum regenerators are arranged to either side of the turboshafts in large compartments; the regenerators turn at approximately 30 RPM. Within each side compartment, a vertical bulkhead divides the regenerators into low-pressure exhaust (occupying approximately of the regenerator) and high-pressure inlet (the remaining ) sections. As a regenerator rotates through the exhaust section, it picks up waste heat from the exhaust gases, then as it continues to rotate into the inlet section, the heat is transferred to the compressed air, preheating it before fuel is added in the combustors.
In addition to improving thermodynamic efficiency, the regenerators serve to muffle engine noise and heat, reducing exhaust temperatures. The exhaust section operates at a lower pressure than the inlet section, so regenerator sealing is important to minimize loss of high-pressure compressed air.
Engine braking
In a conventional piston engine, engine braking can be used to slow a vehicle without use of the friction brakes; because the power turbine is not mechanically connected to the compressor in a free-turbine turboshaft engine, a similar effect cannot be accomplished. During the development of the Whirlfire engines, GM found the gasifier turbine could generate more power than was required to operate the compressor, so for the fifth-generation GT-309 (1964), GM and Allison coupled the gasifier and power turboshafts using a clutch to extract some of that surplus power. The resulting system, which Allison branded Power Transfer, gave the GT-309 an engine braking effect and improved fuel economy at partial load.
Fuel
As external combustion engines, the GM Whirlfire gas turbines were capable of burning a wide variety of fuels; for example turbine engines burning powdered coal were fitted to a Cadillac Eldorado and Oldsmobile Delta 88 in the early 1980s as a response to the 1979 oil crisis. Other potential sources of fuel included methanol, ethanol, liquefied coal, and shale oil.
Models
GT-300/302
The first engine, carrying an internal designation of GT-300 (1953), did not have a regenerator. The GT-300 had an output of when the gasifier (compressor) turbine was spinning at 26,000 RPM and the free (power) turbine was spinning at 13,000 RPM. The weight of the entire engine unit was . The GT-300 was fitted to an "Old Look" transit bus, which was branded "Turbo-Cruiser". To reduce overall size, the single large burner was replaced by two smaller burners and the engine was re-designated GT-302, which was fitted to Firebird I (XP-21).
The GT-300 was designed with a 3.5:1 compression ratio and nominal design turboshaft speeds of 24,000 RPM (gasifier) and 12,000 RPM (power). Engine accessories are driven by the gasifier turboshaft through a perpendicular bevel gear arrangement; a conventional automotive starting motor is used to crank the accessory drive shaft (and gasifier turboshaft). A new nickel-base alloy, designated GMR-235, was developed and patented for the turbine blades in the Whirlfire engine.
Externally, the Turbo-Cruiser was distinguished from piston-powered buses by "turbocruiser" script lettering on the sides, blanked-out rear windows, and a large central exhaust stack at the roof. The rearmost seats were replaced by "a complete mobile laboratory with a large [rear-facing] instrumentation panel" for two engineers. Operating experience with the Turbo-Cruiser showed the engine's mechanical durability; according to W.A. Turunen, "on several occasions, pieces of instrumentation have passed through the machine. The turbine buckets were bent, but in no instance did they fail even after subsequent running of damaged parts." The bus accumulated in testing.
Brake-specific fuel consumption (BSFC) was a notable issue, which at 1.63 lb/hp·h was significantly greater than that of a comparable Detroit Diesel 8V71 diesel engine (approximately 0.40 lb/hp·h), even though the turbine was lighter. Other planned improvements would target throttle lag, which was caused by accelerating the gasifier turbine to peak speed, and lack of engine braking.
GT-304
GT-304 (1956) was the first GM gas turbine to include a regenerator, which used exhaust heat to warm intake air, improving fuel consumption to 0.77 lb/hp·h. As fitted to Firebird II, GT-304 output was at a gasifier turbine speed of 35,000 RPM. The gasifier turbine idled at 15,000 RPM and the power turbine operated at up to 28,000 RPM. Overall compression ratio in the gasifier stage was 3.5:1. Turbine inlet temperature was increased to from ; after GM Research re-rated the temperature resistance of the GMR-235 superalloy. With the regenerators, the engine weight increased to ; each regenerator was . 7.27:1 reduction gearing made the output shaft speed compatible with conventional automobile accessories. A fluid input coupling was used between the engine and transmission; in addition, larger accessories were powered from the transmission, not the gasifier turboshaft, as it had been discovered that at idle, accessory power draw could exceed available surplus power.
The GT-304 also was fitted to the first Turbo-Titan, a heavy-duty Chevrolet Model 10413 truck-tractor with tandem rear axles; Turbo-Titan was tested with various loads, demonstrating superior acceleration and gradeability compared to the Loadmaster V-8 engine that was removed, a overhead valve V-8 with output.
GT-305
The GT-305 (1958) fitted to Firebird III had an output of (at turbine speeds of 33,000 RPM gasifier / 27,000 RPM power) and weight of . With a regenerator and additional component refinements, GT-305 achieved a brake-specific fuel consumption of 0.55 lb/hp·h, an improvement of 25% compared to the earlier GT-304; similarly, the engine weight of the GT-305 was reduced by 25% compared to the 304. External dimensions were long, high, and wide. Exhaust temperature had been reduced considerably; the GT-305 exhaust was at full power, decreasing to at idle.
Firebird III had a two-cylinder auxiliary power unit for accessories and a special grade retarder to simulate engine braking, which Jan Norbye criticized as resulting from "the refusal of the turbine experts to tackle the problems at the base ... these two systems seem of dubious value except in an application where cost is no object".
The engine was redesignated GMT-305 in 1959 and further development for regular production was handed off from GM Research to Allison Transmission. As the GMT-305, it incorporated approximately of nickel in alloys, including the turbine blades (GMR-235), turbine wheels (16-25-6), turboshafts (4340), turbine bolts (Inconel X), turbine and bulkhead casings (SAE 60347), and combustion chambers (Hastelloy X). The first GMT-305 prototypes began shipping in November 1959 for fitment to U.S. military vehicles, including the M56 Scorpion and a 28-foot personnel boat. The Whirlfire-powered M56 underwent winter conditions testing and accumulated of service with little trouble. In addition, the GMT-305 was fitted to an ore-hauling truck at an open-pit nickel mine in Sudbury, Ontario.
GT-309
GT-307, a proposed successor to GT-305, was designed in 1960 but never built. Instead, GM moved away from passenger cars with GT-309 (1964), which was designed for heavy-duty applications, as demonstrated by its use in the Chevrolet Turbo Titan III truck and Turbo-Cruiser II/III buses; for this updated engine, the gasifier turbine and compressor were designed to operate at 35,700 RPM, generating at a power shaft speed of 35,000 RPM (with reduction gearing, 4,000 RPM). Stall torque was at idle. In addition, the GT-309 was fitted to a conventional GMC Astro-95 cabover tractor and the RTX transit bus prototype of 1969.
Compared to earlier engines, the turbine inlet temperature was increased again to . The gasifier (compressor) shaft idled at 15,000 RPM and BSFC was 0.45 lb/hp·h. A "power transfer" system was used to harness some of the gasifier turbine to the output shaft; with this engaged, engine braking was available at an effectiveness of two to three times the equivalent effect as using a piston engine. The engine used a single rotating drum regenerator, moved to the top of the engine with a single combustor. With this reconfiguration, GT-309 measured long, wide, and high, consuming air at a rate of with a compression ratio of 3.9:1. Whenever the transmission was in gear, the engine operated at a ready-idle speed of 19,300 RPM (gasifier turboshaft) and was capable of accelerating to 32,130 RPM in 2.7 seconds to combat throttle lag. The single regenerator preheated the compressed air from , resulting in exhaust gas temperatures of less than .
Unlike the GT-305, commercial development of the GT-309 was handled by Detroit Diesel instead. However, Detroit Diesel and Allison were merged in 1970, resulting in the Detroit Diesel Allison Division of General Motors Corporation (DDAD), reuniting road vehicle gas turbine development in GM.
GT-404/505/606
The final evolution of the GM gas turbine engine was the GT-404, which was developed by DDAD and had dropped the Whirlfire branding. GT-404 output was at gasifier / power turbine speeds of 37,103 / 30,830 RPM, with a stall torque of and BSFC of 0.475 lb/hp·h. Compared to the preceding GT-309, the 404 returned to dual side-mounted regenerators, although the 404 used discs rather than drums. The 404 was considerably larger and heavier than the preceding 309, at (W×L×H) and . A special version of the Allison Transmission HT-740 heavy-duty automatic transmission was planned to be mated with the GT-404, which omitted the torque converter and saved some space.
The first GT-404 engines were shipped from the Detroit Diesel Allison plant in Indianapolis to Detroit and Portland, Oregon in 1971, for installation in prototype over-the-road tractors. In addition, it served in the electrical power generator set for the MIM-104 Patriot surface-to-air missile fire unit. The list price of the first versions, at , reportedly was "barely adequate to cover production costs" and not competitive with conventional diesel engines. Serial production was scheduled to begin in 1972, and GT-505 and 606 variants were planned to follow in 1973, with increased outputs of (505) and (606). Limited field experience with the 404 was obtained between 1974 and 1977, including use in MC-7 Super 7 Turbocruiser buses for Greyhound. Later versions of the 404 used advanced materials, including aluminum silicate ceramic disc regenerators.
The GM RTS-3T candidate prototype (1972) tested under the Transbus Program also used a GT-404. In the late 1970s, the U.S. Departments of Energy and Transportation jointly conducted the Gas Turbine Transit Bus Demonstration Program, using the DDA GT-404 gas turbine in both transit buses and highway coaches. 11 GT-404-4 engines were built for this program; this version was rated at a nominal output with a turbine inlet temperature of ; as-shipped, tested engine output varied from , with BSFC between 0.428 to 0.447 lb/hp·h. Under the demonstration program, four GT-404-powered RTS-II (T8H-603) transit buses and four MCI MC-8 Americruiser coaches were placed into revenue service for the MTA (in Baltimore, Maryland) and Greyhound Lines, respectively. The MTA terminated its test in July 1981 after three months in revenue service; by the time the study concluded in 1983, it had been placed under the auspices of NASA.
Because GM declined to convert the RTS-II buses to accommodate the turbine engines, a fabricator was contracted to custom install them; the GT-404-4 engines were hand-built at a per-unit cost of . Externally, the modified RTS-II turbine buses for MTA required a boxy cover at back of the bus to accommodate the relocated air conditioning condenser, changing the profile from a slanted rear end to a boxier look. The turbine engines were installed in Greyhound MC-8 fleet numbers 5991 (engine T6), 5992 (T5, later T8), 5993 (T7), and 5994 (T5, later T9); and MTA RTS-II fleet numbers 3318 (T11), 3319 (T11, later T14), 3320 (T14, later T13), and 3321 (T13, later T15 & T12). Engine T10 was cannibalized for parts before being installed into a bus. Over of service with Greyhound, the four MC-8 buses averaged , less efficient than diesel piston-engined peer coaches, which achieved on average. Similarly, over of revenue service with MTA, the four RTS-II buses averaged , consuming more than peer transit buses, which averaged on similar routes.
See also
Chrysler turbine engines, prototype contemporaneous engines with comparable levels of development
References
External links
1950s turboshaft engines
1960s turboshaft engines
1970s turboshaft engines
1980s turboshaft engines
General Motors engines
Gas turbines
Centrifugal-flow turbojet engines | GM Whirlfire engine | [
"Technology"
] | 3,516 | [
"Engines",
"Gas turbines"
] |
71,763,673 | https://en.wikipedia.org/wiki/Scandit | Scandit AG, commonly referred to as Scandit, is a Swiss technology company that provides smart data capture software. Their technology allows any smart device equipped with a camera to scan barcodes, IDs and text and to perform additional functions using augmented reality and advanced analytics.
The company has more than 550 employees, operating from offices in Zürich, Boston, London, Warsaw, Tampere, Singapore and Tokyo. In 2022, the company completed its Series D venture round, reaching a valuation of US$1 billion.
Scandit's core business is to provide computer vision-based smart data capture technology that enables barcode scanning, text and object recognition for enterprise workflows. Their smart data capture SDKs are deployed in a range of industries such as retail, transport, logistics and manufacturing for use cases including inventory management, order fulfilment, store operations, mobile self-scanning, asset tracking and field operations.
Scandit Smart Data Capture technologies are used by three of the top five global courier companies and eight of the top ten US grocers.
History
The three founders namely, Samuel Mueller, Christian Floerkemeier, and Christof Roduner met as doctoral students studying at ETH Zurich in 2009. Initially they set to work on a ten-year-old concept developed by their tutor Friedemann Mattern who had explored the potential of then low-resolution smartphone cameras as barcode scanning devices.
With a proof-of-concept in place, Scandit was formed a year later in 2010 to bring the product to market. In recognition of the technology's potential, Samuel Mueller was awarded the Fast Start award at the 2011 edition of the ACES awards, organised by the Science|Business Innovation Board. In the same year, Scandit was awarded the CTI Startup Label and debuted at 89th on the annual Top 100 Best Swiss Startups league table. Scandit was also recognised on the world stage, winning a US$150,000 prize in the Calling All Innovators competition run by Nokia.
In 2017 Scandit raised US$7.5 million Series A funding to drive development of their mobile barcode scanning technologies.
Series B followed in July 2018, raising a further US$30 million to drive development of new solutions.
A third round of funding (Series C) was secured in May 2020 as demand for ‘contactless apps’ surged. At the same time, Scandit reported recurring revenues had tripled and their customer base had doubled in the previous two years.
In October 2020, Samsung Electronics announced a new partnership with Scandit. Under the terms of the agreement, Scandit's mobile computer vision software would be integrated into Samsung's Knox framework and deployed initially on the Android-powered Galaxy Xcover Pro smartphone.
In April 2021 Scandit's computer vision technology was selected by the National Health Service to digitize the COVID-19 testing program in the UK. The system was used at all fixed and mobile test sites, in home-testing kits and at schools to conduct over 1.2 million tests every day.
In July 2021 Google partnered with Scandit to add barcode scanning capabilities to their AppSheet development platform.
In February 2022, Scandit raised US$150 million Series D funding, pushing Scandit's market valuation above US$1 billion. Scandit also reported that their annual recurring revenue had doubled since May 2020 with over 1,700 global customers in both B2B and B2C sectors.
In the same month, SAP announced their new SAP Warehouse Operator app for the Apple iPhone will include the Scandit barcode scanning SDK. Scandit technology had previously been included in SAP Fiori for SAP S/4HANA too.
In March 2022, Scandit was ranked as one of the 100 most promising B2B retail tech companies in the world by CB Insights. A few months later, Scandit was named as one of Switzerland's ten most valuable startups after achieving unicorn status.
In July 2022 the Scandit Barcode Scanner SDK (including MatrixScan) was made available on the Pega Marketplace for use in AI-powered decisioning and workflow automation projects.
Products
Scandit's core capabilities include software-based barcode scanning, ID scanning and text recognition functionality. Scandit describes their product and support ecosystem as the ‘Smart Data Capture platform’.
The platform incorporates the enterprise-grade barcode scanning and text recognition software library (SDK) base product, driven by proprietary computer vision algorithms. The SDK can be integrated into third-party apps, allowing any smart device with a camera, such as smartphones, to become a mobile barcode scanner. The SDK can be complemented by more complex features such as image processing, analytics and augmented reality.
As well as these core capabilities, Scandit also provides additional functionality including MatrixScan, which captures and decodes multiple barcodes simultaneously, and ShelfView which uses proprietary image recognition technology and augmented reality for stock management by retailers.
References
Swiss companies established in 2009
2009 establishments in Switzerland
Swiss brands
Software companies established in 2009
Automatic identification and data capture | Scandit | [
"Technology"
] | 1,033 | [
"Data",
"Automatic identification and data capture"
] |
71,763,816 | https://en.wikipedia.org/wiki/EC%2011507-2253 | EC 11507-2253 is a post-AGB star located about 81,000 light years, or 25 kpc, away from Earth in the constellation of Corvus. Located in the distant galactic halo, over 50,000 light years above the galactic plane, EC 11507-2253 is very isolated and the rest of its life (likely only a few tens of thousands of years) will be spent in the halo as well, far from much of the stellar population. The apparent magnitude is only about 15, and it was only discovered in 1997 in a survey for blue objects at high latitudes (above the galactic plane).
Properties
EC 11507-2253 is quite a hot post-AGB star. Initial analysis of its spectrum upon its discovery in 1997 yielded a spectral type of B5. Analysis of its spectrum in 2005 has revealed a temperature of about 15,500 K, which makes sense given its spectral type.
In 2015, a distance catalogue of post-AGB stars based on an assumed luminosity given the post-AGB star type and location was made, which included EC 11507-2253, which was assigned an estimated luminosity of based on its status as an outer halo post-AGB star. This also yielded its distance value of 24.93 kpc. Modelling published with Gaia Data release 3 gives a similar luminosity of and a radius of .
References
B-type stars
Post-asymptotic-giant-branch stars
Corvus (constellation) | EC 11507-2253 | [
"Astronomy"
] | 315 | [
"Corvus (constellation)",
"Constellations"
] |
71,764,437 | https://en.wikipedia.org/wiki/Chrysalis%20%28hypothetical%20moon%29 | In the astronomy of the Solar System, Chrysalis is a hypothetical moon of Saturn, named in 2022 by scientists of the Massachusetts Institute of Technology using data from the Cassini–Huygens mission. The moon would have been torn apart by Saturn's tidal forces, somewhere between 200 and 100 million years ago. Up to 99% of the moon's mass would have been swallowed by Saturn, with the remaining 1% forming the rings of Saturn. The origin of Saturn's rings from the destruction of a satellite has been previously proposed by other authors.
Chrysalis was hypothesized to be similar in size and mass to Iapetus, with a similar water-ice composition, and to have orbited somewhere between Iapetus and Titan. Its orbit around Saturn may have been degraded as a result of Titan's orbit expanding due to interactions of the Saturnian system with a resonance with Neptune, resulting in the increasing eccentricity of Chrysalis's orbit until being torn apart during a close encounter with Saturn by its parent planet's gravitational force.
The hypothetical moon was named after the pupa stage of a butterfly, with the rings of Saturn representing its emergence from the chrysalis.
See also
Rings of Saturn § Formation and evolution of main rings
References
Hypothetical moons
Moons of Saturn
Hypothetical bodies of the Solar System | Chrysalis (hypothetical moon) | [
"Astronomy"
] | 273 | [
"Astronomical hypotheses",
"Astronomical myths",
"Astronomy stubs",
"Hypothetical astronomical objects",
"Astronomical objects",
"Planetary science stubs"
] |
71,764,827 | https://en.wikipedia.org/wiki/Janet%20Ellzey | Janet L. Ellzey is an American mechanical engineer specializing in combustion, especially involving burners made of porous media. She is a professor in the J. Mike Walker Department of Mechanical Engineering at the University of Texas at Austin, where she holds an Engineering Foundation Centennial Teaching Fellowship in Engineering.
Education and career
Ellzey majored in mechanical engineering at the University of Texas at Austin, graduating in 1978 and continuing on for a master's degree in 1980. She earned a Ph.D. in mechanical engineering at the University of California, Berkeley in 1985.
After working as a staff scientist at the Naval Research Laboratory, she returned to the University of Texas at Austin as a faculty member in 1990. There, she was an associate dean from 2007 to 2009, and vice provost for international programs from 2009 to 2017.
She was a founder of the university's Projects with Underserved Communities program, which aims to develop engineering projects to help communities in developing nations. In 2021–2022 she won a Jefferson Science Fellowship from the National Academies of Science and Engineering, funding her to work as Senior Science Advisor in the Local, Faith, and Transformative Partnerships Hub of the United States Agency for International Development (USAID) Bureau of Development, Democracy, and Innovation.
Recognition
The University of Texas at Austin Department of Mechanical Engineering named Ellzey as a distinguished alumni member in 2011. She was elected to the inaugural 2018 class of Fellows of The Combustion Institute, "for excellent research in reacting and inert porous media".
References
Year of birth missing (living people)
Living people
American mechanical engineers
21st-century American women engineers
21st-century American engineers
University of Texas at Austin alumni
University of California, Berkeley alumni
University of Texas at Austin faculty
Fellows of the Combustion Institute | Janet Ellzey | [
"Chemistry"
] | 356 | [
"Fellows of the Combustion Institute",
"Combustion"
] |
71,764,867 | https://en.wikipedia.org/wiki/Capital%20in%20the%20Anthropocene | Capital in the Anthropocene () is a 2020 non-fiction book by Japanese academic Kohei Saito. Drawing from writings on ecology and natural science by Karl Marx, the book presents a Marxist argument for degrowth as a means of mitigating climate change. Capital in the Anthropocene was an unexpected commercial success in Japan, selling over half a million copies.
Background
Kohei Saito is an associate professor of philosophy at the University of Tokyo. He writes on ecology and political economy from a Marxist perspective, attributing the financial crisis of 2007–2008, the climate crisis, and the Fukushima nuclear disaster as influencing his orientation towards a Marxist interpretation of politics. These events prompted him to consider why "in such an affluent society, there are so many people living in poverty, without access to medical care, and unable to make ends meet," and that despite living in an outwardly convenient and prosperous society, "many people feel that there are no good prospects for the future".
Capital in the Anthropocene draws from Marx's unpublished notebooks on ecological research written late in his life, particularly his writing on natural science and the metabolic rift. In these writings, Marx argues that capitalism has created an "irreparable rift in the interdependent process of social metabolism" and examines self-governing agricultural communes that existed in pre-capitalist societies. From this foundation, Saito mounts an argument for degrowth based on Marx's conclusions.
Synopsis
Saito argues that while sustainable growth has become a central organizing principle in global responses to climate change, the expectation of perpetual growth has only exacerbated the climate crisis. He is particularly critical of the Sustainable Development Goals (SDGs), describing them as "the new opium of the masses" in regards to what he believes is the impossibility for the goals to be achieved under a capitalist system. Instead, Saito advocates for degrowth, which he conceives as the slowing of economic activity through the democratic reform of labor and production.
In practical terms, Saito's conception of degrowth involves the end of mass production and mass consumption, decarbonization through shorter working hours, and the prioritization of essential labor such as caregiving. The author argues that capitalism creates artificial scarcity by pursuing profit based on commodity value rather than the usefulness of what is produced, citing the privatization of the commons for purposes of capital accumulation as an example. Saito argues that by returning the commons to a system of social ownership, it is possible to restore abundance and focus on economic activities that are essential for human life.
Publication history
Capital in the Anthropocene was published by Shueisha on September 17, 2020. In 2021, a Korean translation was published under the title 지속 불가능 자본주의 ( 'Unsustainable Capitalism'). Marx in the Anthropocene: Towards the Idea of Degrowth Communism, an English-language book that builds on the material published in Capital in the Anthropocene, was published by Cambridge University Press in 2023. An English translation was published under the title Slow Down: The Degrowth Manifesto by Astra House in 2024.
Reception
Capital in the Anthropocene was awarded the 2021 New Book Award by Chuokoron-Shinsha, and was selected as one of the "Best Asian Books of the Year" at the Asia Book Awards in 2021.
The book was an unexpected mainstream commercial success in Japan, selling over a quarter million copies by May 2021 and over a half million copies by September 2022. Saito attributes the book's success to its popularity among young people and its coincidental release during the COVID-19 pandemic, stating the widening of the wealth gap that occurred as a result of the COVID-19 recession increased the visibility of social and economic inequality while revealing "how destructive a capitalist society based on excessive production and consumption can be."
The success of Capital in the Anthropocene has been credited with provoking a renewed interest in Marxist thought in Japan, with bookstores reporting an increase in sales in books about Marxism and Saito appearing on NHK's television series 100 Pun de Meicho to present a four-part introduction to Marx's Capital.
References
Further reading
2020 non-fiction books
Degrowth
Marxist books
Shueisha books
Japanese non-fiction books | Capital in the Anthropocene | [
"Environmental_science"
] | 905 | [
"Degrowth",
"Environmental ethics"
] |
71,765,640 | https://en.wikipedia.org/wiki/TMEM144 | Transmembrane Protein 144 (TMEM144) is a protein in humans encoded by the TMEM144 gene.
Gene
Transmembrane Protein 144 is located on the plus strand of chromosome 4 (4q32.1), spanning a total of 40,857 base pairs. The TMEM144 gene transcribes a mRNA sequence 3,210 nucleotides in length and composed of 13 exons.
Protein
There exist two isoforms of human Transmembrane Protein 144. Isoform one consist of 345 amino acids with a total mass of 37.6 kDa. This isoform has a theoretical isoelectric point of 6.63. The second isoform is 169 amino acids long with a mass of 18.3 kDa.
Expression
TMEM144 is over-expressed in adult brain tissue with low regional specificity. TMEM144 appears enriched in oligodendrocytes and immune cells, such as dendritic cells and monocytes.
Cellular Localization
Precise cell localization has multiple predicted locations. Localization tools state TMEM144 is likely found in the plasma membrane, endoplasmic reticulum, Lysosome/Vacuole, or Golgi apparatus. However, an immunofluorescent staining of various human cell lines display localization to the mitochondria.
Post Translational Modifications
There exists five predicted post translational modifications for TMEM144, including four sites of phosphorylation and a sumoylation site.
Interacting Proteins
Several proteins have been observed to be physically associated with TMEM144, including Transmembrane Protein 237, Homocysteine-Responsive Endoplasmic Reticulum-Resident Ubiquitin-Like Domain Member 2 Protein, Translocase of Inner Mitochondrial Membrane Domain-Containing Protein 1, Free Fatty Acid Receptor 2, Aquaporin 6, Serine Rich Single-Pass Membrane Protein 1, and Adrenoceptor Beta 2.
Homology
Transmembrane Protein 144 arose approximately 694 million years ago in desert locust. It can be found in both vertebrates and invertebrates. It takes TMEM144 approximately 6.8 million years to make a 1% change to its amino acid sequence, indicating a moderately low rate of evolution.
Ortholog Table
Clinical Significance
Transmembrane Protein 144 is predicted to be a direct or indirect negative regulator of kisspeptin. High expression of TMEM144 is prognostically favorable for patient with endometrial cancer. Whereas in patients with pancreatic cancer, high expression of TMEM144 is associated with poor prognostic outcomes.
References
Genes on human chromosome 4
Proteins | TMEM144 | [
"Chemistry"
] | 568 | [
"Biomolecules by chemical classification",
"Proteins",
"Molecular biology"
] |
71,770,439 | https://en.wikipedia.org/wiki/SW%20Ursae%20Majoris | SW Ursae Majoris is a cataclysmic binary star system in the northern circumpolar constellation of Ursa Major, abbreviated SW UMa. During quiescence it has an apparent visual magnitude of 16.5–17, which is too faint to be visible to the naked eye. Based on parallax measurements, it is located at a distance of approximately 526 light years from the Sun.
The variable nature of this object was noted by L. Tseraskaya in 1909 when it increased in brightness to 10th magnitude. It was determined to be a U Geminorum star, indicating this is a binary star system. A short orbital period of 81.8 minutes was determined by A. W. Shafter and associates in 1986. The same year, E. L. Robinson and associates detected superhumps with a period of 84.0 minutes. Large amplitude quasi-periodic oscillations were observed by T. Kato and associates in 1992, which is a property of SU UMa-type dwarf novae.
When the system is in a quiet period, it displays a periodicity of 15.9 minutes and has a marginal emission of soft X-rays. This is likely the rotation period of the white dwarf, and the system resembles an intermediate polar with a strongly-magnetized white dwarf as the accreting component. It undergoes outbursts that vary in brightness and duration. During quiescence, it is estimated that about 70% of the bolometric luminosity of the system is produced by the white dwarf, with almost all the rest produced by the accretion disk.
References
Further reading
Dwarf novae
White dwarfs
Ursa Major
Ursae Majoris, SW | SW Ursae Majoris | [
"Astronomy"
] | 348 | [
"Ursa Major",
"Constellations"
] |
71,771,891 | https://en.wikipedia.org/wiki/CD%E2%88%9234%208618 | CD−34°8618, also known as KELT-13 or WASP-167, is a yellowish-white hued star located in the southern constellation of Centaurus. It has an apparent magnitude of 10.52, making it readily visible in medium sized telescopes, but not to the naked eye. Based on parallax measurements from the Gaia spacecraft, the object is estimated to be approximately 1,350 light years away from the Solar System. It appears to be drifting closer to it, having a radial velocity of .
Description
WASP-167 has a stellar classification of F1 V, indicating that it is an ordinary F-type main-sequence star that is generating energy via hydrogen fusion at its core. At present it has 1.59 times the mass of the Sun and 1.94 times the radius of the Sun. It radiates 8.34 times the luminosity of the Sun from its photosphere at an effective temperature of . WASP-167 has an iron abundance 26% above solar levels, making it metal enriched — common among planetary hosts. The object has completed 63% of its main sequence lifetime at an age of 1 billion years. Like many hot stars, WASP-167 spins rapidly, having a projected rotational velocity of , meaning it completes a rotation under 2 days.
Planetary system
A Hot Jupiter was discovered in a tight, 2 day retrograde orbit the star by the SuperWASP and the KELT. WASP-167 was observed to have non-radial pulsations, which might be caused by the planet's close orbit. It has an equilibrium temperature of and is nearly tidally locked, similar to Mercury.
References
F-type main-sequence stars
Planetary systems with one confirmed planet
Centaurus
CD-34 08618 | CD−34 8618 | [
"Astronomy"
] | 357 | [
"Centaurus",
"Constellations"
] |
53,277,091 | https://en.wikipedia.org/wiki/TRAPPIST-1g | TRAPPIST-1g, also designated as 2MASS J23062928-0502285 g and K2-112 g, is an exoplanet orbiting around the ultra-cool dwarf star TRAPPIST-1, located away from Earth in the constellation Aquarius. It was one of four new exoplanets to be discovered orbiting the star in 2017 using observations from the Spitzer Space Telescope. The exoplanet is within the optimistic habitable zone of its host star. It was found by using the transit method, in which the dimming effect that a planet causes as it crosses in front of its star is measured.
The second-most-distant-known planet in its system, TRAPPIST-1g is a planet somewhat larger than Earth and with a similar density, meaning it is likely a rocky planet.
Physical characteristics
Mass, radius, and temperature
TRAPPIST-1g has a radius of and a mass of , with a density only slightly less than Earth's, though initial estimates suggested its density was only 4.186 g/cm3, about 76% of Earth's. Based on mass-radius calculations and its distant location relative to its host star (0.047 AU) and the fact that the planet only receives 25.2% of the stellar flux that Earth does, the planet is likely covered by a thick ice envelope if an atmosphere does not exist.
Atmosphere
TRAPPIST-1g could have a global water ocean or an exceptionally thick steam atmosphere. According to a simulation of magma ocean-atmosphere interaction, TRAPPIST-1g is likely to retain a large fraction of primordial steam atmosphere during the initial stages of evolution, and therefore today is likely to possess a thick ocean covered by atmosphere containing hundreds of bars of abiotic oxygen.
On 31 August 2017, astronomers at the Hubble Space Telescope reported the first evidence of possible water content on the TRAPPIST-1 exoplanets.
Host star
The planet orbits an (M-type) ultracool dwarf star named TRAPPIST-1. The star has a mass of 0.08 M☉ and a radius of 0.11 R☉. It has a temperature of 2,550 K. The age of the star is about billion years old. In comparison, the Sun is 4.6 billion years old and has a temperature of 5,778 K. The star is metal-rich, with a metallicity ([Fe/H]) of 0.04, or 109% the solar amount. This is particularly odd as such low-mass stars near the boundary between brown dwarfs and hydrogen-fusing stars should be expected to have considerably less metal content than the Sun. Its luminosity (L☉) is 0.05% of that of the Sun.
The star's apparent magnitude, or how bright it appears from Earth's perspective, is 18.8, too dim to be seen with the naked eye.
Orbit
TRAPPIST-1g orbits its host star with an orbital period of about 12.354 days and an orbital radius of about 0.0451 times that of Earth's (compared to the distance of Mercury from the Sun, which is about 0.38 AU). This is in the outer limit of TRAPPIST-1's theoretical habitable zone. The orbit of TRAPPIST-1g has an eccentricity of 0.00208, much lower than that of Earth and the lowest in its system. Its orbit varies by only about 41,000 kilometers (compared to about 5 million km for Earth), meaning the planet's climate is likely very stable. It is in a 3:2 orbital resonance with TRAPPIST-1h and a 3:4 resonance with TRAPPIST-1f.
See also
List of extrasolar candidates for liquid water
List of transiting exoplanets
List of potentially habitable exoplanets
List of nearest terrestrial exoplanet candidates
TRAPPIST-1d
TRAPPIST-1e
References
Exoplanets discovered in 2017
Near-Earth-sized exoplanets
Near-Earth-sized exoplanets in the habitable zone
Transiting exoplanets
TRAPPIST-1
Aquarius (constellation)
J23062928-0502285 g | TRAPPIST-1g | [
"Astronomy"
] | 888 | [
"Constellations",
"Aquarius (constellation)"
] |
53,277,189 | https://en.wikipedia.org/wiki/TRAPPIST-1e | TRAPPIST-1e, also designated as 2MASS J23062928-0502285 e, is a rocky, close-to-Earth-sized exoplanet orbiting within the habitable zone around the ultracool dwarf star TRAPPIST-1, located away from Earth in the constellation of Aquarius. Astronomers used the transit method to find the exoplanet, a method that measures the dimming of a star when a planet crosses in front of it.
The exoplanet was one of seven discovered orbiting the star using observations from the Spitzer Space Telescope. Three of the seven (e, f, and g) are in the habitable zone/"goldilocks" zone. TRAPPIST-1e is similar to Earth's mass, radius, density, gravity, temperature, and stellar flux. It is also confirmed that TRAPPIST-1e lacks a cloud-free hydrogen-dominated atmosphere, meaning it is more likely to have a compact atmosphere like the terrestrial planets in the Solar System.
In November 2018, researchers determined that of the seven exoplanets in the multi-planetary system, TRAPPIST-1e has the best chance of being an Earth-like ocean planet, and the one most worthy of further study regarding habitability. According to the Habitable Exoplanets Catalog, TRAPPIST-1e is among the best potentially habitable exoplanets discovered.
Physical characteristics
Mass, radius, density, composition and temperature
TRAPPIST-1e was detected with the transit method, where the planet blocked a small percentage of its host star's light when passing between it and Earth. This allowed scientists to accurately determine the planet's radius at , with a small uncertainty of about . Transit-timing variations and advanced computer simulations helped constrain the planet's mass, which turned out to be , or about 15% less massive than Venus. TRAPPIST-1e has 82% the surface gravity of Earth, the third-lowest in the system. Its radius and mass are also the third-least among the TRAPPIST-1 planets.
With both the radius and mass of TRAPPIST-1e determined with low error margins, scientists could accurately calculate the planet's density, surface gravity, and composition. Initial density estimates in 2018 suggested it has a density of 5.65 g/cm3, about 1.024 times Earth's density of 5.51 g/cm3. TRAPPIST-1e appeared to be unusual in its system, as it was the only planet with a density consistent with a pure rock-iron composition, and the only one with a higher density than Earth (TRAPPIST-1c also appeared to be entirely rock, but with a lower density than TRAPPIST-1e). The higher density of TRAPPIST-1e implies an Earth-like composition and a solid rocky surface. This also appeared to be unusual among the TRAPPIST-1 planets, as most were thought to have densities consistent with being completely covered in either a thick steam/hot CO2 atmosphere, a global liquid ocean, or an ice shell. However, refined estimates show that all planets in the system have similar densities, consistent with rocky compositions, with TRAPPIST-1e having a somewhat lower but still Earth-like bulk density.
The planet has a calculated equilibrium temperature of given an albedo of 0, also known as its "blackbody" temperature. For a more realistic Earth-like albedo however, this provides an unrealistic picture of the surface temperature of the planet. Earth's equilibrium temperature is 255 K; it is Earth's greenhouse gases that raise its surface temperatures to the levels we experience. If TRAPPIST-1e has a thick atmosphere, its surface could be much warmer than its equilibrium temperature.
Host star
The planet orbits an (late M-type) ultracool dwarf star named TRAPPIST-1. The star has a mass of 0.089 – near the boundary between a brown dwarf and low-mass star – and a radius of 0.121 . It has a temperature of and is 7.6 billion years old. In comparison, the Sun is 4.6 billion years old and has a temperature of . The star is metal-rich, with a metallicity ([Fe/H]) of 0.04, or 109% the solar amount. This is particularly odd as such low-mass stars near the boundary between brown dwarfs and hydrogen-fusing stars should be expected to have considerably less metal content than the Sun. Its luminosity () is 0.0522% of that of the Sun.
The star's apparent magnitude, or how bright it appears from Earth's perspective, is 18.8. Therefore, it is far too dim to be seen with the naked eye.
Orbit
TRAPPIST-1e orbits its host star quite closely. One full revolution around TRAPPIST-1 takes only 6.099 Earth days (~146 hours) to complete. It orbits at a distance of , or just under 3% the separation between Earth and the Sun. For comparison, the closest planet in the Solar System, Mercury, takes 88 days to orbit the Sun at a distance of . Despite its close proximity to its host star, TRAPPIST-1e gets only about 60% the starlight that Earth gets from the Sun due to the low luminosity of its star. The star would cover an angular diameter of about 2.17 degrees from the surface of the planet, and so would appear about four times larger than the Sun does from Earth.
Atmosphere
TRAPPIST-1e is confirmed to not have a cloud-free hydrogen-dominated atmosphere, meaning it is more likely to have a compact, hydrogen-free atmosphere like those of the Solar System's rocky planets, further raising the chances of habitability. Hydrogen is a powerful greenhouse gas, so if there was enough to be easily detected, it would mean that the surface of TRAPPIST-1e would be inhospitable. Since such an atmosphere is not present, it raises the chances for the planet to have a more Earth-like atmosphere instead. However, no atmosphere has been detected, and it is still possible that the planet has no atmosphere at all. Additionally, no helium emission from TRAPPIST-1e was detected .
Habitability
The exoplanet was announced to be orbiting within the habitable zone of its parent star, the region where, with the correct conditions and atmospheric properties, liquid water may exist on the surface of the planet. TRAPPIST-1e has a radius of around 0.91 , so it is likely a rocky planet. Its host star is a red ultracool dwarf, with only about 8% of the mass of the Sun (close to the boundary between brown dwarfs and hydrogen-fusing stars). As a result, stars like TRAPPIST-1 have the potential to remain stable for up to 12 trillion years, which is over 2,000 times longer than the Sun. Because of this ability to live for such a long period of time, it is likely TRAPPIST-1 will be one of the last remaining stars in the Universe, when the gas needed to form new stars will be exhausted, and the existing stars begin to die off.
Other factors and 2018 studies
Despite being likely tidally locked – meaning one hemisphere permanently faces the star while the other does not – which may reduce the habitability of the planet, more detailed studies of TRAPPIST-1e and the other TRAPPIST-1 planets released in 2018 determined that the planet is in fact one of the most Earth-sized worlds found, with 91% the radius, 77% the mass, 102.4% the density (5.65 g/cm3), and 93% the surface gravity. TRAPPIST-1e is confirmed to be a terrestrial planet with a solid, rocky surface. It is cool enough for liquid water to pool on the surface, but not so cold that it would freeze like on TRAPPIST-1f, g, and h.
The planet receives a stellar flux 60.4% that of Earth, about a third lower than that of Earth but significantly more than that of Mars. Its equilibrium temperature ranges from to , depending on how much light the planet reflects into space. Both of these are between those of Earth and Mars as well. In addition, its atmosphere is confirmed to not be dense or thick enough to harm the habitability potential as well, according to models by the University of Washington. The atmosphere, if it is dense enough, may also help to transfer additional heat to the dark side of the planet.
2024 studies
According to a 2024 study, based on modeling, TRAPPIST-1e could be having its atmosphere stripped by its host star, possibly as a result of its short orbital period, which would make it inhospitable to life. The same phenomenon could impact the atmospheres of the other planets in this system. , it is not yet known whether TRAPPIST-1e has an atmosphere based on observation.
Future observations
As it is one of the most promising potentially habitable exoplanets known, TRAPPIST-1e was an early target of the James Webb Space Telescope in a research program led by Nikole Lewis. Launched on 25 December 2021, the telescope allows more extensive analysis of the planet's atmosphere, facilitating the search for any chemical signs of life, or biosignatures.
Discovery
A team of astronomers headed by Michaël Gillon used the TRAPPIST (Transiting Planets and Planetesimals Small Telescope) telescope at the La Silla Observatory in the Atacama Desert, Chile, to observe TRAPPIST-1 and search for orbiting planets. By utilising transit photometry, they discovered three Earth-sized planets orbiting the dwarf star; the innermost two are tidally locked to their host star while the outermost appears to lie either within the system's habitable zone or just outside of it. The team made their observations from September–December 2015 and published its findings in the May 2016 issue of the journal Nature.
The original claim and presumed size of the planet was revised when the full seven-planet system was revealed in 2017:
"We already knew that TRAPPIST-1, a small, faint star some 40 light years away, was special. In May 2016, a team led by Michaël Gillon at Belgium’s University of Liege announced it was closely orbited by three planets that are probably rocky: TRAPPIST-1b, c and d ...
"As the team kept watching shadow after shadow cross the star, three planets no longer seemed like enough to explain the pattern. "At some point we could not make sense of all these transits," Gillon said.
"Now, after using the space-based Spitzer telescope to stare at the system for almost three weeks straight, Gillon and his team have solved the problem: TRAPPIST-1 has four more planets.
"The planets closest to the star, TRAPPIST-1b and c, are unchanged. But there's a new third planet, which has taken the d moniker, and what had looked like d before turned out to be glimpses of e, f, and g. There's a planet h, too, drifting farthest out, and only spotted once."
Gallery
Videos
See also
List of extrasolar candidates for liquid water
List of potentially habitable exoplanets
List of transiting exoplanets
References
Exoplanets discovered in 2017
Near-Earth-sized exoplanets
Transiting exoplanets
TRAPPIST-1
Aquarius (constellation)
Near-Earth-sized exoplanets in the habitable zone
J23062928-0502285 e | TRAPPIST-1e | [
"Astronomy"
] | 2,438 | [
"Constellations",
"Aquarius (constellation)"
] |
53,277,204 | https://en.wikipedia.org/wiki/TRAPPIST-1h | TRAPPIST-1h, also designated as 2MASS J23062928-0502285 h, is an exoplanet orbiting around the ultra-cool dwarf star TRAPPIST-1, located away from Earth in the constellation Aquarius. It was one of four new exoplanets to be discovered orbiting the star in 2017 using observations from the Spitzer Space Telescope. In the following years, more studies were able to refine its physical parameters.
The outermost known planet in its system, it is roughly one third the mass of Earth, and about 76% as large. Its relatively low density indicates that it is likely water-rich, like several other planets in the system.
Physical characteristics
Mass, radius, and temperature
TRAPPIST-1h has a radius of , a mass of , and about 57% Earth's surface gravity. It was initially estimated to have a density of 3.97 g/cm3, similar to that of Mars. Given this density, about ≤5% of its mass may be water, likely in the form of a thick ice shell, since it only receives about 13% of the stellar flux that Earth does. It has an equilibrium temperature of , similar to that of Earth's south pole.
Host star
TRAPPIST-1h orbits the ultracool dwarf star TRAPPIST-1. It is 0.121 and 0.089 , with a temperature of 2,511 K and an age between 3 and 8 billion years. For comparison, the Sun has a temperature of 5,778 K and is about 4.5 billion years old. TRAPPIST-1 is also very dim, with about 0.0005 times the luminosity of the Sun. The star's apparent magnitude, or how bright it appears from Earth's perspective, is 18.8. Therefore, it is too dim to be seen with the naked eye.
Orbit
Despite it being the most distant known planet in its system, TRAPPIST-1h orbits its host star with an orbital period of 18.868 days and an orbital radius of about 0.0619 AU. This is even smaller than Mercury's orbit around the Sun (which is about 0.38 AU).
Stable liquid water
Although TRAPPIST-1h's orbit falls near its star's frost line, it could harbor liquid water under an H2-rich atmosphere, either primordial or resulting from continuous outgassing combined with internal heating, although existence of such atmosphere was strongly disfavored by observations in 2021 and 2022. If ice-covered, it could also potentially harbor a subsurface ocean by way of tidal heating, which could lead to cryovolcanism in the form of erupting geysers.
See also
List of transiting exoplanets
References
Exoplanets discovered in 2017
Near-Earth-sized exoplanets
Transiting exoplanets
TRAPPIST-1
Aquarius (constellation)
Sub-Earth exoplanets
J23062928-0502285 h | TRAPPIST-1h | [
"Astronomy"
] | 636 | [
"Constellations",
"Aquarius (constellation)"
] |
53,277,860 | https://en.wikipedia.org/wiki/Lian%20Pin%20Koh | Koh Lian Pin (born 1976 in Singapore) is a Singaporean conservation scientist. He is Vice President (Sustainability & Resilience), and Chief Sustainability Scientist at the National University of Singapore (NUS), where he oversees and champions sustainability-related research. He employs a whole-of-University strategy to bridge academia with policy makers, industry and civil society, driving the change needed across all sectors to tackle the twin planetary crises of climate change and biodiversity loss.
By initiating and spearheading engagements with stakeholders locally and at international fora, Koh seeks to promote societal understanding of the world we live in, and amplify the university’s and Singapore’s contributions to sustainability efforts globally.
He is presently also the Kwan Im Thong Hood Cho Temple Chair Professor of Conservation, and Director of the Centre for Nature-based Climate Solutions at NUS.
An internationally renowned name in the field of sustainability and environmental science, Koh is one of the most highly cited conservation scientists in the world, with over 20 years of international research experience. His previous stints include Swiss National Science Foundation Professor at ETH Zurich, Chair of Applied Ecology and Conservation at the University of Adelaide, Vice President of Science Partnerships and Innovation at Conservation International Foundation. He was also the Founding Director of Conservation Drones, a non-profit organisation that seeks to introduce drone technology to conservation scientists and practitioners worldwide.
Koh has received multiple awards including the Frontiers Planet Prize, National Champion, in 2023, the Australian Research Council Future Fellowship Level II in 2014, the Swiss National Science Foundation Professorship in 2011, the ETH Fellowship in 2008, and was also named a World Economic Forum Young Global Leader in 2013.
In 2020, Koh received a prestigious award from the National Research Foundation of the Singapore Prime Minister's Office under its Returning Singaporean Scientists Scheme. Established in 2013, the Scheme seeks to attract outstanding overseas-based Singaporean research leaders back to Singapore to take up leadership positions in Singapore's autonomous universities and publicly funded research institutes. Koh was the sixth recipient of the award.
On 14 January 2021, Koh was appointed as one of nine Nominated Members of Parliament (NMP) in the 14th Parliament of Singapore, which began on 21 January 2021.
Education
Koh studied at Hwa Chong Institution for his pre-tertiary education in Singapore. He completed his Bachelor of Science (with First Class Honours) and Master of Science degrees at the National University of Singapore in 2001 and 2003, respectively. Koh received his PhD from the Department of Ecology and Evolutionary Biology at Princeton University, New Jersey, US in 2008. Following that, he received postdoctoral training at ETH Zurich.
Research
Koh's scientific contributions include the study of species co-extinctions and modeling the environmental impacts of industrial agriculture across the tropics.
His research focuses on developing innovative science and science-based decision support tools to reconcile societal needs with environmental protection. He addresses this challenge through field studies and experiments, computer simulations and modelling, as well as by co-opting emerging technologies for use in environmental research and applications.
His more recent research as Director of the Centre for Nature-based Climate Solutions seeks to produce policy-relevant science on nature-based climate solutions – tackling climate change by protecting and better managing natural ecosystems – to address knowledge gaps, build capacity and deliver pragmatic solutions and innovations to inform climate policies, strategies and actions to achieve the centre's vision.
Koh’s research is complemented by his rich work in advocacy, which has seen him offer a science-based perspective to socioeconomic and environmental issues on both local and global platforms, including speaking at the United Nations Climate Change Conferences (COP27 in Sharm El Sheik and COP28 in Dubai), TED Global and TEDx conferences, among others.
Impact
Koh has published over 150 journal articles, including Nature, Science, and Proceedings of the National Academy of Sciences USA. He is one of the most highly cited conservation scientists in the world. His research has received over 28,000 citations (with an h-index of >80).
Koh is a pioneer in the use of low-cost drone technology for environmental applications. Koh founded Conservation Drones which has received numerous awards and media coverage.
Koh was an invited speaker at the TED Global 2013: Think Again conference in Edinburgh, where he spoke on the positive use of drones.
Outreach
Koh is a regular plenary speaker at international meetings, including the WWF Fuller Symposium in 2012, the Clinton Global Initiative University in 2013, and the Intergovernmental Eye on Earth Summit in 2015.
Koh's work has been featured in international media, including the New York Times, Smithsonian Magazine, Scientific American, NewScientist, the Telegraph, among others.
References
1976 births
Living people
Ecologists
Princeton University alumni
Academic staff of the University of Adelaide
National University of Singapore alumni
Singaporean Nominated Members of Parliament
Academic staff of ETH Zurich | Lian Pin Koh | [
"Environmental_science"
] | 997 | [
"Ecologists",
"Environmental scientists"
] |
53,278,977 | https://en.wikipedia.org/wiki/Language%20Server%20Protocol | The Language Server Protocol (LSP) is an open, JSON-RPC-based protocol for use between source code editors or integrated development environments (IDEs) and servers that provide "language intelligence tools": programming language-specific features like code completion, syntax highlighting and marking of warnings and errors, as well as refactoring routines. The goal of the protocol is to allow programming language support to be implemented and distributed independently of any given editor or IDE. In the early 2020s, LSP quickly became a "norm" for language intelligence tools providers.
History
LSP was originally developed for Microsoft Visual Studio Code and is now an open standard. On June 27, 2016, Microsoft announced a collaboration with Red Hat and Codenvy to standardize the protocol's specification. The protocol was originally supported and adopted by these three companies. Its specification is hosted and developed on GitHub.
Background
Modern IDEs provide programmers with sophisticated features like code completion, refactoring, navigating to a symbol's definition, syntax highlighting, and error and warning markers.
For example, in a text-based programming language, a programmer might want to rename a method read. The programmer could either manually edit the respective source code files and change the appropriate occurrences of the old method name into the new name, or instead use an IDE's refactoring capabilities to make all the necessary changes automatically. To be able to support this style of refactoring, an IDE needs a sophisticated understanding of the programming language that the program's source is written in. A programming tool without such an understanding—for example, one that performs a naive search-and-replace instead—could introduce errors. When renaming a read method, for example, the tool should not replace the partial match in a variable that might be called readyState, nor should it replace the portion of a code comment containing the word "already". Neither should renaming a local variable read, for example, end up altering identically-named variables in other scopes.
Conventional compilers or interpreters for a specific programming language are typically unable to provide these language services, because they are written with the goal of either transforming the source code into object code or immediately executing the code. Additionally, language services must be able to handle source code that is not well-formed, e.g. because the programmer is in the middle of editing and has not yet finished typing a statement, procedure, or other construct. Additionally, small changes to a source code file which are done during typing usually change the semantics of the program. In order to provide instant feedback to the user, the editing tool must be able to very quickly evaluate the syntactical and semantical consequences of a specific modification. Compilers and interpreters therefore provide a poor candidate for producing the information needed for an editing tool to consume.
Prior to the design and implementation of the Language Server Protocol for the development of Visual Studio Code, most language services were generally tied to a given IDE or other editor. In the absence of the Language Server Protocol, language services are typically implemented by using a tool-specific extension API. Providing the same language service to another editing tool requires effort to adapt the existing code so that the service may target the second editor's extension interfaces.
The Language Server Protocol allows for decoupling language services from the editor so that the services may be contained within a general-purpose language server. Any editor can inherit sophisticated support for many different languages by making use of existing language servers. Similarly, a programmer involved with the development of a new programming language can make services for that language available to existing editing tools. Making use of language servers via the Language Server Protocol thus also reduces the burden on vendors of editing tools, because vendors do not need to develop language services of their own for the languages the vendor intends to support, as long as the language servers have already been implemented. The Language Server Protocol also enables the distribution and development of servers contributed by an interested third party, such as end users, without additional involvement by either the vendor of the compiler for the programming language in use or the vendor of the editor to which the language support is being added.
LSP is not restricted to programming languages. It can be used for any kind of text-based language, like specifications or domain-specific languages (DSL).
Technical overview
When a user edits one or more source code files using a language server protocol-enabled tool, the tool acts as a client that consumes the language services provided by a language server. The tool may be a text editor or IDE and the language services could be refactoring, code completion, etc.
The client informs the server about what the user is doing, e.g., opening a file or inserting a character at a specific text position. The client can also request the server to perform a language service, e.g. to format a specified range in the text document. The server answers a client's request with an appropriate response. For example, the formatting request is answered either by a response that transfers the formatted text to the client or by an error response containing details about the error.
The Language Server Protocol defines the messages to be exchanged between client and language server. They are JSON-RPC preceded by headers similar to HTTP. Messages may originate from the server or client.
The protocol does not make any provisions about how requests, responses and notifications are transferred between client and server. For example, client and server could be components within the same process exchanging JSON strings via method calls. They could also be different processes on the same or on different machines communicating via network sockets.
Registry
There are lists of LSP-compatible implementations, maintained by the community-driven Langserver.org or Microsoft.
References
Further reading
External links
Communications protocols
Open standards
Programming tools | Language Server Protocol | [
"Technology"
] | 1,195 | [
"Computer standards",
"Communications protocols"
] |
53,279,262 | https://en.wikipedia.org/wiki/Instance%20selection | Instance selection (or dataset reduction, or dataset condensation) is an important data pre-processing step that can be applied in many machine learning (or data mining) tasks. Approaches for instance selection can be applied for reducing the original dataset to a manageable volume, leading to a reduction of the computational resources that are necessary for performing the learning process. Algorithms of instance selection can also be applied for removing noisy instances, before applying learning algorithms. This step can improve the accuracy in classification problems.
Algorithm for instance selection should identify a subset of the total available data to achieve the original purpose of the data mining (or machine learning) application as if the whole data had been used. Considering this, the optimal outcome of IS would be the minimum data subset that can accomplish the same task with no performance loss, in comparison with the performance achieved when the task is performed using the whole available data. Therefore, every instance selection strategy should deal with a trade-off between the reduction rate of the dataset and the classification quality.
Instance selection algorithms
The literature provides several different algorithms for instance selection. They can be distinguished from each other according to several different criteria. Considering this, instance selection algorithms can be grouped in two main classes, according to what instances they select: algorithms that preserve the instances at the boundaries of classes and algorithms that preserve the internal instances of the classes. Within the category of algorithms that select instances at the boundaries it is possible to cite DROP3, ICF and LSBo. On the other hand, within the category of algorithms that select internal instances, it is possible to mention ENN and LSSm. In general, algorithm such as ENN and LSSm are used for removing harmful (noisy) instances from the dataset. They do not reduce the data as the algorithms that select border instances, but they remove instances at the boundaries that have a negative impact on the data mining task. They can be used by other instance selection algorithms, as a filtering step. For example, the ENN algorithm is used by DROP3 as the first step, and the LSSm algorithm is used by LSBo.
There is also another group of algorithms that adopt different selection criteria. For example, the algorithms LDIS, CDIS and XLDIS select the densest instances in a given arbitrary neighborhood. The selected instances can include both, border and internal instances. The LDIS and CDIS algorithms are very simple and select subsets that are very representative of the original dataset. Besides that, since they search by the representative instances in each class separately, they are faster (in terms of time complexity and effective running time) than other algorithms, such as DROP3 and ICF.
Besides that, there is a third category of algorithms that, instead of selecting actual instances of the dataset, select prototypes (that can be synthetic instances). In this category it is possible to include PSSA, PSDSP and PSSP. The three algorithms adopt the notion of spatial partition (a hyperrectangle) for identifying similar instances and extract prototypes for each set of similar instances. In general, these approaches can also be modified for selecting actual instances of the datasets. The algorithm ISDSP adopts a similar approach for selecting actual instances (instead of prototypes).
References
Machine learning
Data mining | Instance selection | [
"Engineering"
] | 672 | [
"Artificial intelligence engineering",
"Machine learning"
] |
53,280,578 | https://en.wikipedia.org/wiki/Box-counting%20content | In mathematics, the box-counting content is an analog of Minkowski content.
Definition
Let be a bounded subset of -dimensional Euclidean space such that the box-counting dimension exists.
The upper and lower box-counting contents of are defined by
where is the maximum number of disjoint closed balls with centers
and radii .
If , then the common value, denoted , is called the box-counting content of .
If , then is said to be box-counting measurable.
Examples
Let denote the unit interval.
Note that the box-counting dimension and the Minkowski dimension coincide with a common value of 1; i.e.
Now observe that , where denotes the integer part of . Hence is box-counting measurable with .
By contrast, is Minkowski measurable with .
See also
Box counting
References
Fractals | Box-counting content | [
"Mathematics"
] | 169 | [
"Mathematical analysis",
"Functions and mappings",
"Mathematical objects",
"Fractals",
"Mathematical relations"
] |
53,280,922 | https://en.wikipedia.org/wiki/Hallia | Hallia is a taxonomic synonym that may refer to:
Hallia = Alysicarpus
Hallia = Psoralea
References | Hallia | [
"Biology"
] | 28 | [
"Set index articles on plants",
"Set index articles on organisms",
"Plants"
] |
53,280,992 | https://en.wikipedia.org/wiki/HydroCAD | HydroCAD is a computer-aided design (CAD) program used by civil engineers for modeling the hydrology and hydraulics (H&H) of stormwater runoff. Its use as a tool has grown in the U.S. as rules for managing stormwater have become more stringent. Specifically, the National Pollutant Discharge Elimination System (NPDES), last updated in December 2016, regulates point source pollution by municipal governments, industrial facilities and agricultural facilities. The NPDES was introduced in 1972 as part of the Clean Water Act, and is administered by the U.S. Environmental Protection Agency (EPA) in partnership with state environmental agencies.
H&H software such as HydroCAD is important in the implementation of the Low-Impact Development approach to stormwater management that is gaining popularity throughout the U.S. and Canada.
History
The company was founded in 1977 as Applied Microcomputer Systems (AMS), initially developing custom software for technical and scientific applications. In the early years of personal computers, AMS produced various other programming tools for technical professionals.
In 1985, AMS began development of the HydroCAD Stormwater Modeling System as a response to growing hydrology requirements facing civil engineers. The program, ultimately introduced in 1986 for HP workstations, made it possible to conduct complex calculations on desktop computers rather than only on mainframes. It also added new graphical interfaces to improve ease of use.
In 2001, the HydroCAD software was re-written as a native Windows application, using Borland's Delphi programming environment, and released as HydroCAD 6.0.
In 2004, the company officially changed its name to “HydroCAD Software Solutions LLC”. Its headquarters office is on Chocorua Mountain Highway (also known as Route 16) in the town of Tamworth, New Hampshire.
The latest HydroCAD version 10.2 was released in May 2022. Future updates are expected approximately twice a year, allowing HydroCAD to stay current with the ever-expanding market of stormwater storage products (chambers) and flow control devices.
== References ==
External links
Eng-Tips Forum
Training Videos
Hydrology models
Hydraulics
Computer-aided design software | HydroCAD | [
"Physics",
"Chemistry",
"Biology",
"Environmental_science"
] | 449 | [
"Hydrology",
"Biological models",
"Physical systems",
"Hydraulics",
"Hydrology models",
"Environmental modelling",
"Fluid dynamics"
] |
53,281,588 | https://en.wikipedia.org/wiki/Comet%20%28experiment%29 | COMET (Coherent Muon to Electron Transition) is a nuclear physics experiment in J-PARC, Tokai, Japan. In contrast to the usual muon decay to an electron and neutrino, COMET seeks to look for neutrinoless muon to electron conversion, where the electron flies away with an energy of 104.8 MeV. Muon to electron conversion is not forbidden in the Standard Model but the branching ratio is about considering neutrino oscillations. In beyond the Standard Model approaches the muon to electron conversion process can be as high as e.g. via the supersymmetric .
COMET will be using a new beamline connecting the J-PARC main ring and the J-PARC Nuclear and particle Physics Experimental Hall (NP hall).
The current spokesperson is Kuno Yoshitaka alongside project manager Mihara Satoshi. The collaboration consists of universities coming from 15 countries.
See also
Mu2e experiment
References
External links
SINDRUM
MECO
Particle experiments
Physics beyond the Standard Model
Science and technology in Japan | Comet (experiment) | [
"Physics"
] | 211 | [
"Unsolved problems in physics",
"Nuclear and atomic physics stubs",
"Particle physics",
"Nuclear physics",
"Physics beyond the Standard Model"
] |
53,282,729 | https://en.wikipedia.org/wiki/Dinogunellin | Dinogunellins are unusual toxic phospholipids found in the roe of some fishes, and is one of the best studied ichthyotoxin. These phospholipids could be found as a complex with non-toxic proteins like in the cabezon toxin or in the lipostichaerin.
Occurrence
Dinogunellins were detected in the mature roe of four fishes: the cabezon or marbled sculpin Scorpaenichthys marmoratus, the blennies Stichaeus grigorjewi and Stichaeus nozawae, and the killifish Fundulus heteroclitus.
The presence of dinogunellins has been discarded in the roe of the carp Cyprinus carpio, the sculpin Hemitripterus villosus, the blenny Lumpenus fowleri, and the lamprey Lapetra japonica.
Structure
Dinogunellins are unusual phospholipids having a nucleotide instead of the typical glycerol in their structure. They consist of an adenine nucleotide, with a 2-aminosuccinimide attached to the phosphorus moiety and a fatty acid attached to the oxygen from either the C2' or the C3' of the sugar moiety. The fatty acid chain could be either the eicosapentaenoic acid (Dinogunellin-A and Dinogunellin-B) or the stearidonic acid (Dinogunellin-C and Dinogunellin-D). In consequence, Dinogunellin-A and Dinogunellin-B have the same molecular formula (C34H49N8O9P) and molecular weight (744.8 g/mol), an so do Dinogunellin-C and Dinogunellin-D (C32H47N8O9P; 718.7 g/mol).
Pharmacology
When intraperitoneally administered to mice, dinogunellins have a mean lethal dose (LD50) of 25 mg/kg. Dinogunellins are also orally toxic to mice and guinea pigs and has also deleterious effects on humans. A few hours after ingestion, humans develop abrupt onset diaphoresis, chills, abdominal pain and cramping, with nausea and vomiting followed by voluminous, non-bloody diarrhea.
Analysis made on the cabezon toxin showed that its effects start 12 hours after administration and is characterized by several signs such as diarrhea, nasal discharge, and death. In addition, cabezon toxin showed cytotoxicity on fibroblast in culture. Besides, toxin administration causes an increase in white cell number, but with a decrease in lymphocytes associated with the observation of spleen necrosis.
References
External links
Dinogunellin A (Pubchem)
Dinogunellin B (Pubchem)
Dinogunellin C (Pubchem)
Dinogunellin D (Pubchem)
Ichthyotoxins
Phospholipids
Nucleosides | Dinogunellin | [
"Chemistry"
] | 658 | [
"Phospholipids",
"Signal transduction"
] |
53,282,876 | https://en.wikipedia.org/wiki/NGC%205837 | NGC 5837 is a barred spiral galaxy in the constellation Boötes. It was discovered on 19 June 1887 by Lewis A. Swift.
Supernovae
A Type Ia Supernova, SN 2014ac, was discovered 9 March 2014, and on 16 June 2015, a Type IIN Supernova, SN 2015z, was discovered.
References
External links
Barred spiral galaxies
Boötes
5837
09686
053817 | NGC 5837 | [
"Astronomy"
] | 86 | [
"Boötes",
"Constellations"
] |
53,282,928 | https://en.wikipedia.org/wiki/Agni%20Vlavianos%20Arvanitis | Agni Vlavianos Arvanitis (9 March 1936 – 7 April 2018) was a professor and researcher in biology. Her main contribution lies in the field of biopolitics, and the theory of bios. She graduated from Barnard College in 1957 (B.A.), New York University (M.S.) and the University of Athens (Ph.D.). She worked as a researcher at the Museum of Natural History in New York, the University of California at Berkeley, and the University of Paris. She has also taught Biology, Biochemistry and Human Genetics at the Friends Seminary in New York, the American Community Schools Academy in Athens, and the University of Maryland.
The biopolitics theory
Her theory of biopolitics sees biopolitics as a conceptual and operative framework for societal development, promoting bios (Greek = life) as the central theme in every human endeavor, be it policy, education, art, government, science or technology. This concept uses bios as a term referring to all forms of life on our planet, including their genetic and geographic variation.
Achievements
In 1985, Agni Vlavianos Arvanitis founded the Biopolitics International Organisation (B.I.O.) with the goal of promoting respect for the gift of bios (life) and international cooperation for the protection of the environment. B.I.O created an international network of associates in over 160 countries around the world, with scholars and decision-makers supporting its goals and projects.
Recognition
Agni Vlavianos Arvanitis was the recipient of a number of international distinctions including election as Honorary President for Life of the United Nations Association in Sri Lanka; election as an International Patron of the Global Cooperation for a Better World; the commemorative Gold Medal of Honor for outstanding achievements and dedication to personal and professional goals, as well as election as 1994 Woman of the year by ABI. Notably she has been appointed Doctor Honoris Causa of Mendeleyev University in Moscow, and Honorary professor of St. Petersburg State Technological University of Plant Polymers.
References
1936 births
2018 deaths
Biopolitics
American women biologists
Barnard College alumni
New York University alumni
National and Kapodistrian University of Athens alumni
21st-century American women scientists | Agni Vlavianos Arvanitis | [
"Engineering",
"Biology"
] | 461 | [
"Biopolitics",
"Genetic engineering"
] |
53,282,932 | https://en.wikipedia.org/wiki/NewStore | NewStore, Inc. provides Omnichannel-as-a-Service for enterprise retail brands worldwide. Its mobile-first, modular cloud platform includes point of sale (POS), order management (OMS), inventory, store fulfillment, clienteling, and native consumer app solutions.
The company was founded in 2015 by Stephan Schambach, who also founded Intershop Communications and Demandware, which was acquired by Salesforce in 2016 for US$2.8 billion. It is headquartered in Boston, USA with offices in Berlin, Germany and Utrecht, Netherlands. It received a Series A investment of US$38M in September 2015 and Series B investment of US$50M in July 2017. Additionally, the company raised US$45M in Series B-1 financing in July 2021, a strategic investment to accelerate company growth.
Funding
History
Founded in 2015 by Stephan Schambach, NewStore, Inc. has established itself as a leader in Omnichannel-as-a-Service (OaaS) for global retail brands. The company's mobile-first, modular cloud platform empowers retailers with a comprehensive suite of solutions including point of sale (POS), order management (OMS), inventory management, store fulfillment, clienteling, and native consumer apps. In April 2024, NewStore appointed Mike DeSimone as CEO with Stephan Schambach transitioning to Chairman of the Board. Notably, in January 2024, NewStore released its 10th annual Omnichannel Leadership Report, assessing the omnichannel capabilities of nearly 700 retailers across 10 countries and highlighting the significant opportunity for improvement in omnichannel adoption.
References
2015 establishments in the United States
Retail point of sale systems
Providers of services to on-line companies
Online companies of the United States
Companies based in Boston | NewStore | [
"Technology"
] | 374 | [
"Retail point of sale systems",
"Information systems"
] |
53,283,441 | https://en.wikipedia.org/wiki/Turbo-Hauser%20bases | Turbo-Hauser bases are amido magnesium halides that contain stoichiometric amounts of LiCl. These mixed Mg/Li amides of the type R2NMgCl⋅LiCl are used in organic chemistry as non-nucleophilic bases for metalation reactions of aromatic and heteroaromatic substrates. Compared to their LiCl free ancestors Turbo-Hauser bases show an enhanced kinetic basicity, excellent regioselectivity, high functional group tolerance and a better solubility.
Preparation
Typically Turbo-Hauser bases are prepared by treating an amine with a Grignard reagent and lithium chloride. In some cases they are prepared by treating a lithium amide with MgCl2:
Common Turbo-Hauser bases: R'2NH = iPr2NMgCl·LiCl (iPr-Turbo-Hauser base), TMPMgCl·LiCl, TMP (Turbo-Hauser base or Knochel-Hauser Base)
Structure
In solution, Turbo-Hauser bases participate in temperature- and concentration-dependent equilibria. Diffusion-Ordered Spectroscopy (DOSY) show that at room temperature and high concentrations (0.6 M) dimeric [iPr2NMgCl·LiCl]2 remains intact solution.
Solid State Structure
The iPr-Turbo-Hauser base crystallizes as a dimeric amido bridged contact ion pair (CIP). Due to the high steric demand of the TMP ligand the dimerization process is sterically hindered. This is why the TMP-Turbo-Hauser base crystallizes as a monomeric CIP.
In both structures LiCl coordinates to the magnesium amides.
The solid state structure of TMPMgCl·LiCl is retained almost completely in THF solution independently of temperature and concentration. Due to the high steric demand of the TMP ligand, the THF ligand dissociates from the magnesium cation. This dissociation gives a magnesium amido complex with enhanced reactivity for deprotonation of C-H bonds.
Reactions
Turbo-Hauser bases are used as metalation/deprotonation reagents. In this way, they resemble some organolithium reagents. The lithiated compounds, however, are only stable at low temperatures (e.g. -78 °C) and suffer competing addition reactions (like e.g. Chichibabin reactions). In contrast, the magnesium compounds are less reactive. The magnesium amide complex is stabilized by LiCl. Turbo-Hauser bases display a high functional group tolerance and greater chemoselectivity at high and low temperatures. The resulting reagent is then quenched with an electrophile.
iPr2NMgCl·LiCl and TMPMgCl·LiCl react differently. The TMP-Turbo-Hauser base easily metalates ethyl-3-chlorobenzoate in the C2 position, while the same reaction carried out with the iPr-Turbo-Hauser base resulted in no metalation at all. Instead, an addition-elimination reaction occurs.
Another difference is illustrated by the differing rates of deprotonation of isoquinoline in THF solution. Whereas TMPMgCl·LiCl required only 2h and 1.1 equivalents, iPr2NMgCl·LiCl needed 12h and 2 equivalents for comparable metalation.
The differing reactivity of the TMP vs iPr-based reagents is related to the fact that the TMP is always a terminal ligand whereas iPr2N is sometimes bridging (μ-). Generally, in organolithium chemistry monomeric species display the most active kinetic species. This could explain why reactions of the monomeric TMP-Turbo-Hauser base are much faster than that of dimeric iPr-Turbo-Hauser base. The regioselective ortho deprotonation reactions of TMPMgCl·LiCl could stem from a sufficient complex-induced proximity effect (CIPE) between the bimetallic aggregate and the functionalized (hetero)aromatic substrate.
Related reagents
Turbo-Grignard reagents used for halide/Mg exchange reactions. "Turbo-Grignards", as they are often called, are aggregates with the formula [i-PrMgCl·LiCl]2
Organozinc-LiCl complexes
References
Magnesium compounds | Turbo-Hauser bases | [
"Chemistry"
] | 925 | [
"Metal amides",
"Coordination chemistry"
] |
53,283,857 | https://en.wikipedia.org/wiki/Alpha%20Profiling | Alpha profiling is an application of machine learning to optimize the execution of large orders in financial markets by means of algorithmic trading. The purpose is to select an execution schedule that minimizes the expected implementation shortfall, or more generally, ensures compliance with a best execution mandate.
Alpha profiling models learn statistically-significant patterns in the execution of orders from a particular trading strategy or portfolio manager and leverages these patterns to associate an optimal execution schedule to new orders. In this sense, it is an application of statistical arbitrage to best execution. For example, a portfolio manager specialized in value investing may have a behavioral bias to place orders to buy while an asset is still declining in value. In this case, a slow or back-loaded execution schedule would provide better execution results than an urgent one. But this same portfolio manager will occasionally place an order after the asset price has already begun to rise in which case it should best be handled with urgency; this example illustrates the fact that Alpha Profiling must combine public information such as market data with private information including as the identity of the portfolio manager and the size and origin of the order, to identify the optimal execution schedule.
Market Impact
Large block orders can generally not be executed immediately because there is no available counterparty with the same size. Instead, they must be sliced into smaller pieces which are sent to the market over time. Each slice has some impact on the price, so on average the realized price for a buy order will be higher than at the time of the decision, or less for a sell order. The implementation shortfall is the difference between the price at the time of the decision and the average expected price to be paid for executing the block, and is usually expressed in basis points as follows.
Alpha Profile
The alpha profile of an order is the expected impact-free price conditioned on the order and the state of the market, form the decision time to the required completion time. In other words, it is the price that one expects for the security would have over the execution horizon if the order were not executed. To estimate the cost of an execution strategy, market impact must be added to the impact-free price. It is well worth stressing that attempts to estimate the cost of alternative schedules without impact adjustments are counter-productive: high urgency strategies would capture more liquidity near the decision time and therefore would always be preferred if one did not account for their impact. In fact, front-loaded execution schedules have a higher average impact cost.
Estimating an alpha profile
One way to compute an alpha profile is to use a classification technique such as Naive Bayes: find in the historical record a collection of orders with similar features, compute the impact-free price for each case, and take the simple average return from trade start over the next few days. This method is robust and transparent: each order is attached to a class of orders that share specific features that can be shown to the user as part of an explanation for the proposed optimal decision. However, an alpha profiling model based on classifying trades by similarity has limited generalization power. New orders do not always behave in the same way as other orders with similar features behaved in the past. A more accurate estimation of alpha profiles can be accomplished using Machine Learning (ML) methods to learn the probabilities of future price scenarios given the order and the state of the market. Alpha profiles are then computed as the statistical average of the security price under various scenarios, weighted by scenario probabilities.
Risk-adjusted Cost
Optimal execution is the problem of identifying the execution schedule that minimizes a risk-adjusted cost function, where the cost term is the expected effect of trading costs on the portfolio value and the risk term is a measure of the effect of trade execution on risk. It is difficult to attribute the effect of trade execution on portfolio returns, and even more difficult to attribute its effect on risk, so in practice an alternate specification is often used: cost is defined as the implementation shortfall and risk is taken to be the variance of the same quantity. While this specification is commonly used, it is important to be aware of two shortcomings. First, the implementation shortfall as just defined is only a measure of the cost to the portfolio if all orders are entirely filled as originally entered; if portfolio managers edit the size of orders or some orders are left incomplete, opportunity costs must be considered. Second, execution risk as just defined is not directly related to portfolio risk and therefore has little practical value.
Optimal Execution Schedule
A method for deriving optimal execution schedules that minimize a risk-adjusted cost function was proposed by Bertsimas and Lo. Almgren and Chriss provided closed-form solutions of the basic risk-adjusted cost optimization problem with a linear impact model and trivial alpha profile. More recent solutions have been proposed based on a propagator model for market impact, but here again the alpha profile is assumed to be trivial. In practice, impact is non-linear and the optimal schedule is sensitive to the alpha profile. A diffusion model yields a functional form of market impact including an estimate of the speed exponent at 0.25 (trading faster causes more impact). It is possible to derive optimal execution solutions numerically with non-trivial alpha profiles using such a functional form.
References
External links
Learning By Doing
Alpha Profiling
Mathematical finance
Investment | Alpha Profiling | [
"Mathematics"
] | 1,078 | [
"Applied mathematics",
"Mathematical finance"
] |
73,175,612 | https://en.wikipedia.org/wiki/Finland%E2%80%93Russia%20border%20barrier | The Finland–Russia border barrier (, ) is an under construction border barrier in Finland along the Finland–Russia border. The border barrier began to be built in response to the 2022 Russian Invasion of Ukraine by the Marin Cabinet, and gained increased popularity due to the use of migrants in hybrid warfare by the Russian Federation. The border barrier is to be long, covering roughly 15% of the border. The construction of the border barrier began in Imatra on 28 February 2023, and construction is set to be complete in 2027 or 2028.
The border barrier is to be built by the Finnish Border Guard, and the border barrier is to be equipped with razor wire and cameras. The border barrier is predicted to cost around 380 million euros.
Gallery
See also
Finland–Russia relations
References
Border barriers
Barrier
2020s establishments in Finland
21st-century fortifications
Buildings and structures in South Karelia
Buildings and structures under construction in Finland
Fortifications in Finland
Imatra
Reactions to the Russian invasion of Ukraine | Finland–Russia border barrier | [
"Engineering"
] | 199 | [
"Separation barriers",
"Border barriers"
] |
73,175,704 | https://en.wikipedia.org/wiki/Krisp | Krisp (or Krisp Technologies Inc.) is an Armenian AI-based audio processing software company that offers real-time noise and voice suppression technology. The company was founded in 2017 in Yerevan, Armenia, by Davit Baghdasaryan and Artavazd Minasyan, and is based in Berkeley, California.
Krisp's main product is a software application that can remove background noises and voices from audio in real-time. The software uses machine learning algorithms to analyze the audio signal and separate the speech from background noise, allowing the speech to be output in clear, noise-free audio. This technology has a wide range of applications, including teleconferencing, remote work, podcasting, and video production.
The software can be used as a standalone application, or it can be integrated into existing audio applications such as Skype, Zoom, and Slack. This allows users to enjoy noise-free audio without having to switch between different applications. Additionally, the software can be trained to recognize specific types of noise, such as traffic noise or dog barking, which makes it more effective in suppressing noise in specific environments.
Krisp was on the list of Forbes’ America's Most Promising Artificial Intelligence Companies of 2020. Additionally, Krisp was on the TIME List of The 100 Best Inventions of 2020. It has also won two Webby Awards.
In July 2020, Discord added noise suppression into its mobile app using the Krisp audio-filtering technology.
References
Software companies established in 2017
Software companies based in the San Francisco Bay Area
Audio software | Krisp | [
"Engineering"
] | 318 | [
"Audio engineering",
"Audio software"
] |
73,179,359 | https://en.wikipedia.org/wiki/Sophie%20Brasselet | Sophie Brasselet is a French optical physicist whose research interests include nonlinear optics, the optical and fluorescent properties of biomolecules, the optical manipulation of molecules, and the development of instrumentation for biological imaging, over scales ranging from single molecules to multi-cellular tissues. She is a director of research for the French National Centre for Scientific Research (CNRS), and the director of the Fresnel Institute in Marseille (France) also affiliated with the Mosaic advanced photonics group within the institute.
Education and career
Brasselet studied optics and photonics as a student at the École supérieure d'optique, completing her studies in 1994. She went on to a doctorate in 1997 at Paris-Sud University, under the supervision of Joseph Zyss.
After postdoctoral research at Stanford University in California with William E. Moerner, she returned to France in 2000 as an assistant professor at the École normale supérieure de Cachan. In 2006, she moved to Aix-Marseille University and in 2009 she was named a director of research within the CNRS.
Recognition
Brasselet received the CNRS Silver Medal in 2016. In 2022 she won the Léon Brillouin grand prize of the French Optical Society (La Société Française d'Optique), the first female winner of this prize.
She was named a Fellow of Optica, in the 2022 class of fellows, "for advancing fundamental knowledge of molecular nonlinear optics and application to polarization-resolved nonlinear and super resolution orientation microscopy".
References
External links
Year of birth missing (living people)
Living people
Microscopists
Optical physicists
21st-century French physicists
French women physicists
Women in optics
Research directors of the French National Centre for Scientific Research
Fellows of Optica (society) | Sophie Brasselet | [
"Chemistry"
] | 358 | [
"Microscopists",
"Microscopy"
] |
73,181,449 | https://en.wikipedia.org/wiki/Social%20anxiety%20and%20relationship%20development | Social anxiety is characterised by the fear of being judged negatively in social interactions or performance situations, which can lead to emotional distress and disrupt an individual's social functioning. Individuals with social anxiety have a fear of social situations that is so intense that they feel it is beyond their control. Social anxiety disorder usually begins in late childhood and may resemble extreme shyness or avoidance of situations or social interactions. Women are more likely to develop this condition than men, and this gender difference is more pronounced in adolescents and young adults. If left untreated, social anxiety can last for years, even a lifetime.
Communication style
Individuals who experience high levels of social anxiety may adopt a communication style that involves disclosing very little about themselves in situations where they fear negative evaluation. While this approach may seem like a protective measure, it often backfires, leading to the very negative perceptions they were trying to avoid. As a result, establishing close relationships can be difficult, as the process of moving from strangers to acquaintances to friends requires a certain degree of self-disclosure. In fact, a self-protective communication style can actually be a hindrance, limiting both the quantity and quality of relationships that socially anxious individuals are able to develop. Moreover, high levels of social anxiety have been associated with various dysfunctional interpersonal behaviors, such as an inability to assert oneself and a tendency to suppress emotions. This can make it challenging for individuals to navigate conflicts in a healthy and productive manner, as they may struggle to communicate their needs and feelings effectively.
Friendships
"Adolescents who are socially anxious often find themselves with fewer friends, lower quality friendships, fewer interpersonal skills, and more negative peer experiences". Gender differences may play a role, as research suggests that the association between peer acceptance and social anxiety is stronger for girls, and that there are stronger links between social anxiety and friendship quality and quantity for girls as well. Interestingly, individuals with high levels of social anxiety may be more likely to self-disclose to others who also experience high levels of social anxiety, suggesting that friendships between individuals with similar levels of social anxiety can lead to more positive outcomes. Additionally, research has indicated that individuals with high levels of social anxiety often experience cognitive and behavioral uncertainty in the early stages of friendships, which can lead to lower self-efficacy and social performance expectations, making them unsure of how to behave in future interactions and potentially hindering their behavior in social situations. This could result in less positive affect and fewer verbalizations which may lead to relationship deterioration over time and results in lower level of liking among friends. A study led by Hannesdo´ttir and Ollendick found that self-efficacy in social interaction was a better predictor of social anxiety than outcome expectations, indicating that confidence in one's abilities plays an important role in their anxiety about social situation.
Romantic relationships
Social anxiety has a similar impact on both platonic relationships and romantic relationships. The social skills learned through early friendships are often transferred to other peer relationships, including romantic relationships. Studies indicate that there is a developmental trajectory from same-sex friendships to other-sex friendships that aids in the development of heterosexual romantic relationships. Therefore, the quality of one's platonic relationships (both same-sex and other-sex) is predictive of their romantic relationship functioning. However, social anxiety can make it difficult to navigate peer relationships at each of these levels. On the first level, socially withdrawn adolescents are more likely to be excluded by their same-sex peers. The creation of mixed-sex peer groups is facilitated by same-sex peers, so rejection from same-sex peers means fewer opportunities to be involved with other-sex peers. Mixed-sex interactions provides opportunities to learn how to interact with other-sex peers and provide an avenue for meeting potential dating partners. This has negative implications for their romantic life like delayed or limited romantic experiences, or they go into a romantic relationship without having developed the necessary skills and/or without a social support system, which could have a negative effect on their relationship quality and functioning. Socially anxious youth that are sensitive to stressful peer experiences like rejection may also struggle with romantic activities which often expose people to potentially anxiety-provoking situations.
Perceived social support and satisfaction
Research suggests that depression may mediate the relationship between social anxiety and relationship satisfaction due to the high co-morbidity between social anxiety and depression. Depression is strongly associated with decreased relationship satisfaction. Studies have explored the relationship between social anxiety and relationship satisfaction while controlling for depression, with mixed results. One study noted that even after controlling for depression, people with social anxiety remained lower in intimate relationship satisfaction. Other studies have shown no significant association between social anxiety and relationship development after controlling for depression. Perceptions of social support may be lower in socially anxious individuals, which is related to their negative interpretive bias towards relationships.
Social support and social anxiety can be broadly categorized into three categories: received support, provided support, and desired support. Received support refers to the amount of support that a person receives from their partner or social network, while provided support refers to the amount of support that a person provides to their partner or social network. Desired support refers to the ideal amount of support that a person would like to receive from their partner or social network. Most research on this topic suggests that due to their negative interpretation bias of interpersonal relationships, socially anxious individuals tend to perceive less received support from their social network. In other words, they have a tendency to perceive their partner's behavior in a negative light, leading them to feel unsupported even when their partner is behaving in a supportive manner. This negative interpretation bias can exacerbate feelings of social anxiety and may contribute to lower levels of perceived support in social relationships. With women especially, higher levels of social anxiety is associated with reported lower received, desired, and provided support.
References
Wikipedia Student Program
Anxiety
Interpersonal relationships | Social anxiety and relationship development | [
"Biology"
] | 1,182 | [
"Behavior",
"Interpersonal relationships",
"Human behavior"
] |
73,181,722 | https://en.wikipedia.org/wiki/Programming%20language%20design%20and%20implementation | Programming languages are typically created by designing a form of representation of a computer program, and writing an implementation for the developed concept, usually an interpreter or compiler. Interpreters are designed to read programs, usually in some variation of a text format, and perform actions based on what it reads, whereas compilers convert code to lower level.
Design
In programming language design, there are a wide variety of factors to consider. Some factors may be mutually exclusive (e.g. security versus speed). It may be necessary to consider whether a programming language will perform better interpreted, or compiled, if a language should be dynamically or statically typed, if inheritance will be in, and the general syntax of the language. Many factors involved with the design of a language can be decided on by the goals behind the language. It's important to consider the target audience of a language, its unique features and its purpose. It is good practice to look at what existing languages lack, or make difficult, to make sure a language serves a purpose.
Various experts have suggested useful design principles:
As the last paragraph of an article published in 1972, Tony Hoare has provided some general advice for any software project:
“So my advice to the designers and implementer of software of the future is in a nutshell:
do not decide exactly what you are going to do until you know how to do it;
and do not decide how to do it until you have evaluated your plan against all the desired criteria of quality.
And if you cannot do that, simplify your design until you can.”
At a SIGPLAN symposium in 1973, Tony Hoare discussed various language aspects in some detail. He also identifies a number of shortcomings in (then) current programming languages.
“a programming language is a tool which should assist the programmer in the most difficult aspects of his art,
namely program design, documentation, and debugging.”
“objective criteria for good language design may be summarized in five catch phrases:
simplicity, security, fast translation, efficient object code, and readability.”
"It is absurd to make elaborate security checks on debugging runs, when no trust is put in the results, and then remove them in production runs, when an erroneous result could be expensive or disastrous. What would we think of a sailing enthusiast who wears his life-jacket when training on dry land but takes it off as soon as he goes to sea?"
At IFIP Congress 1974, Niklaus Wirth, designer of Pascal, presented a paper "On the design of programming languages”. Wirth listed a number of conflicting suggestions, most notably that a language should be easy to learn and use, it should be usable without new features being added, the compiler should generate efficient code, a compiler should be fast, and that a language should be compatible with libraries, the system it is running on, and programs written in other languages.
Implementation
Interpreters
An interpreter is a program that reads another program, typically as text, as seen in languages like Python. Interpreters read code, and produce the result directly. Interpreters typically read code line by line, and parse it to convert and execute the code as operations and actions.
Compilers
Compilers are programs that read programs, also usually as some form of text, and converts the code into lower level machine code or operations. Compiled formats generated by compilers store the lower level actions as a file. Compiled languages converted to machine code, tend to be a lot faster, as lower level operations are easier to run, and outcomes can be predicted and compiled ahead of time.
Process
Processes of making a programming language may differ from developer to developer; however, here is a general process of how one might create a programming language, which includes common concepts:
Design: Design aspects are considered, such as types, syntax, semantics, and library usage to develop a language.
Consideration: Syntax, implementation, and other factors are considered. Languages like Python interpret code at runtime, whereas languages like C++ follow an approach of basing its compiler off of C's compiler.
Create an implementation: A first implementation is written. Compilers will convert to other formats, usually ending up as low-level as assembly, even down to binary.
Improve your implementation: Implementations should be improved upon. Expand the programming language, aiming for it to have enough functionality to bootstrap, where a programming language is capable of writing an implementation of itself.
Bootstrapping: If using a compiler, a developer may use the process of bootstrapping, where a compiler for a programming language is rewritten in itself. This is good for bug checking, and proving its capability. Bootstrapping also comes with the benefit of only needing to program the language in itself from there-on.
References
Programming language topics | Programming language design and implementation | [
"Engineering"
] | 973 | [
"Software engineering",
"Programming language topics"
] |
73,182,435 | https://en.wikipedia.org/wiki/Pore-C | Pore-C is a genomic technique which utilizes chromatin conformation capture (3C) and Oxford Nanopore Technologies' (ONT) long-read sequencing to characterize three-dimensional (3D) chromatin structure. To characterize concatemers, the originators of Pore-C developed an algorithm to identify alignments that are assigned to a restriction fragment; concatemers with greater than two associated fragments are deemed high order. Pore-C attempts to improve on previous 3C technologies, such as Hi-C and SPRITE, by not requiring DNA amplification prior to sequencing. This technology was developed as a simpler and more easily scalable method of capturing higher-order chromatin structure and mapping regions of chromatin contact. In addition, Pore-C can be used to visualize epigenomic interactions due to the capability of ONT long-read sequencing to detect DNA methylation. Applications of this technology include analysis of combinatorial chromatin interactions, the generation of de novo chromosome scale assemblies, visualization of regions associated with multi-locus histone bodies, and detection and resolution of structural variants.
Background
Although the DNA within eukaryotic cells is linear, it is also intricately folded and packaged to fit within each cell’s nucleus. Thus, specific parts of the genome may be closer in physical space than would otherwise appear to be based on DNA sequence alone. The 3D genome refers to how DNA is spatially organized within cells. The 3D structures found in the genome include active and inactive chromatin, chromatin loops, and topologically associated domains (TADs). These structures function to regulate gene expression. In genomic and epigenomic research, chromatin structure is most often visualized by 3C techniques, which quantify interactions between loci to construct a 3D map. The fundamental 3C technique is used to quantify interactions between pairs of genomic loci. Methods that are derived from this technique, such as 4C, 5C, and Hi-C assays, allow quantification of pairwise interactions between multiple loci. Other variations, such as ChIP-loop and ChIA-PET, combine 3C with immunoprecipitation assays to detect interactions mediated by a protein of interest. These techniques all involve an amplification step, most often using polymerase chain reaction (PCR). A limitation of most current 3D chromatin assays is that they are less useful to categorize interactions between more than two loci, and Pore-C was developed to fill this gap in technology. Additionally, not requiring PCR amplification simplifies the workflow, therefore Pore-C is intended to be simpler and more easily scalable than previous techniques. Pore-C can also be used in populations of cells to characterize topology polymorphisms at specific loci.
Methodology
Many methods to characterize the 3D genome are variations on 3C technology. Like other 3C-based technologies, Pore-C seeks to characterize the architecture of the 3D genome by determining which genomic loci are in close spatial proximity (within ~200 nm). Similar to previous 3C-based methods, Pore-C relies on crosslinking, restriction enzyme digestion, proximity ligation, reverse cross-linking, and protein degradation steps. However, Pore-C is distinct from many previous methods in its subsequent utilization of ONT long-read sequencing, which facilitates the resolution of multi-way chromosome contacts and simultaneous detection of DNA methylation
Cross-linking DNA to protein
First, in order to preserve the 3D structure of the genome from degradation in subsequent steps, DNA is cross-linked to DNA-associated proteins, such as histones.Formaldehyde is used for cross-linking, as it joins DNA to proteins with covalent bonds, thus temporarily locking the 3D genome in place. Specifically, after a series of washes with phosphate-buffered saline (PBS), cells are pelletted with centrifugation, and then resuspended in a formaldehyde and PBS solution. Following a short incubation period, glycine is added to stop the cross-linking reaction. By quenching the excess formaldehyde, glycine prevents the reaction from going to completion, thereby maximizing the efficiency of later steps and ensuring the cross-linking reaction is reversible.
Restriction enzyme digestion and proximity ligation
Cross-linking generates loops of DNA, with each loop arising from a separate locus. To capture long-range interactions between distant loci, potentially from different chromosomes, these loops are first cut and then re-joined back together based on proximity. Although fragments deriving from the same loop may reanneal back together, sometimes fragments from separate loops will ligate together, thus creating chimeric sequences. The cutting and rejoining of DNA is achieved by the in situ restriction enzyme digestion and proximity ligation steps respectively. Specifically, a restriction endonuclease cuts the DNA to create free ends, whereas T4 ligase is used to join fragments together. Ultimately, these steps result in genomic loci close together in physical space being linked together on contiguous DNA segments referred to as concatemers.
Cross-linking reversal, protein degradation, and DNA purification
Next, in order to isolate DNA for sequencing, proteins bound to the DNA have to be detached and degraded. First, Proteinase K, sodium dodecyl sulfate (SDS; a detergent), Tween-20, and nuclease-free water are added. Subsequently, the reaction is heated to 56 °C in a thermocycler for optimal reaction kinetics. Proteinase K degrades proteins, and SDS acts a denaturing agent that disrupts protein structure. This reaction results in the breakage of covalent bonds between DNA and protein and removes potential protein contamination. DNA is then isolated and purified, typically using phenol-chloroform extraction followed by ethanol precipitation.
Size selection, library preparation, and long-read sequencing
Pore-C concatemers undergo size selection prior to library preparation and ONT long-read sequencing. Via size selection, Pore-C is able to detect high-order interactions, which are defined as concatemers containing greater than two DNA fragments. Specifically, Pore-C size selection enriches for DNA sequences greater than 1.5 kb, thereby filtering out shorter concatemers unlikely to contain greater than two fragments. Many size selection methods have been developed for ONT long-read sequencing. For example, Solid Phase Reversible Immobilisation (SPRI) size selection has been used in the Pore-C literature. Following size selection, library preparation for ONT long-read sequencing is performed, usually with a ligation sequencing kit provided by ONT. Key steps include DNA repair and adaptor ligation. Subsequently, DNA is loaded onto flow cells for sequencing, where each concatemer is fed through a pore, aided by a motor protein. Nitrogenous DNA bases are read out by their characteristic disruption of an electric current
Bioinformatic analysis
Overall, bioinformatic approaches applied to Pore-C data allow for the inference of pairwise and multi-way contacts between loci. Since concatemers in Pore-C contain DNA sequences that come from different regions of the genome, aligning sequencing reads to a reference genome is challenging. One solution to this problem involves a bioinformatic pipeline using a greedy piece-wise algorithm. Further analysis of Pore-C results depends on the study and what other data types are available.
Applications
Pore-C is a relatively new method, so its applications have not yet been fully appreciated. A strength of Pore-C over previous methods is its ability to detect interactions between more than two genomic loci. Such high-order interactions enable the study of cellular processes, such as gene expression regulation at a more system-level scale. With statistical methods, Pore-C data can be used to identify cooperative interactions, wherein high-order interactions are observed at a frequency greater than the sum of their expected pairwise contacts. In addition, using ONT long reads, Pore-C can detect DNA methylation, thereby providing an additional layer of epigenetic information to analyze. In the future, Pore-C may be applied to study how the 3D genome changes during developmental processes, such as cellular differentiation. Additionally, Pore-C may be applied to the study of cancer, where the 3D genome is often structurally rearranged, which can result in aberrant gene transcription via processes such as enhancer hijacking.
Use
Advantages
Pore-C has a higher efficiency and fidelity compared to previous methods.
The absence of an amplification step that is required in other chromatin conformation capture methods simplifies the experimental protocol. Additionally, bisulfite conversion (as is required in Methyl-HiC) is not required when detecting DNA methylation.
Pore-C can detect more higher order interactions than Hi-C and other previous methods, because concatemers can span multiple chromosomes and detect distal interactions. Previously, these interactions have been understudied because of the limitations of previous methods.
Because ONT long-read sequencing can detect DNA methylation, Pore-C can be extended to characterize epigenetic interactions and their relationship with chromatin topology.
Limitations
Oxford Nanopore sequencing technology is costly, and therefore Pore-C is more expensive per run when compared to other chromatin conformation capture techniques.
Pore-C throughput is relatively low when compared to other techniques, particularly due to DNA-bound proteins clogging sequencing pores. This can cause it to be less efficient, especially when combined with its relatively high cost per run. However, recent work has shown that the throughput can be increased by treating DNA fragments with proteases to reduce clogging.
Because it relies on ONT long-read sequencing technology, Pore-C is subject to the same limitations. For example, longer reads can be less accurate when compared to shorter reads.
Because Pore-C is a newer technique, it is relatively unproven and has not been tested to the same extent as other chromatin conformation capture techniques.
References
Molecular biology techniques | Pore-C | [
"Chemistry",
"Biology"
] | 2,127 | [
"Molecular biology techniques",
"Molecular biology"
] |
73,184,585 | https://en.wikipedia.org/wiki/Lateral%20olfactory%20tract%20usher%20substance | Lateral olfactory tract usher substance (LOTUS), also known as Cartilage acidic protein-1B (Crtac1B), is a membrane protein produced by neurons. During embryonic development, it is strongly expressed in the olfactory bulb by Mitral cells.
Function
LOTUS is an endogenous antagonist of the Nogo receptor (NgR1) and Paired Immunoglobulin-Like Receptor B (PirB in mice, LilrB2 in humans). These receptors block neuronal outgrowth when activated. By blocking their function, LOTUS promotes neuronal growth, e.g. during the formation of the lateral olfactory tract. As LOTUS generates a permissive brain environment for neuronal regeneration, it may aid recovery after spinal cord injury. It also has been shown to reduce synapse loss in a mouse model of Alzheimer's disease.
References
Neuroscience | Lateral olfactory tract usher substance | [
"Biology"
] | 183 | [
"Neuroscience"
] |
73,185,006 | https://en.wikipedia.org/wiki/Air%20travel%20demand%20reduction | Air travel demand mitigation or aviation demand reduction or air travel demand reduction is a part of transportation demand management and climate change mitigation.
Inhibition of a large or general growth in demand or reduction of demand and need for flights is considered an important part of climate change mitigation as air travel has a substantial impact on the climate. Changes in "behavioral travel parameters can significantly impact the projections for travel demand and the associated energy use and emissions".
Significance to global air travel emissions reduction
Aviation is one of three sectors identified in a study where "demand-side options" can have a large effect in "reaching levels". According to a study, the attainment of the 1.5–2 °C global temperature goal necessitates substantial demand reductions in the critical sectors of aviation, shipping, road freight, and industry, should large-scale negative emissions not be realized. According to the IMAGE model used to project scenarios aimed at limiting global temperature increases to 1.5 °C and 2 °C, it is suggested that achieving deep decarbonization within the aviation sector within the specified timeframe is contingent upon a reduction in air travel in certain markets. The decreases in carbon intensity of aviation energy in net-zero scenarios "are heavily dependent on projected changes in aviation demand and energy intensity". The significant challenges of sustainable aviation fuel expansion, including food security, local community impacts, and land use issues, underscore the importance of simultaneous demand reduction efforts. For instance, according to a report by the Royal Society, to produce enough biofuel to supply the UK's aviation industry would require using half of Britain's farming land which would put major pressures on food supplies.
Tourism is projected to generate up to 40% of total global emissions by 2050. Of climate change mitigation consumption options investigated by a review, the consumption options with "the highest mitigation potential advocate reduction in car and air travel". A study projected a potential reduction of "transport direct emissions by around 50% in the end of the century compared to the baseline" via combined behavioral factors.
Measures
According to the IPCC Sixth Assessment Report, "the greatest Avoid potential" in demand-side mitigation, which consists of Avoid-Shift-Improve (ASI) options, "comes from reducing long-haul aviation and providing short-distance low-carbon urban infrastructure". It lists the following related mobility measures:
Avoid: integrate transport & land use planning, tele-working, fewer long-haul flights, local holidays
Shift: from air travel to high-speed rail
It found that socio-cultural factors promoting a preference for train travel over long-haul flights have the potential to reduce aviation greenhouse gas emissions by 10% to 40% by 2050.
Role of targeted measures in demand mitigation
The IPCC report also concluded that "voluntary behaviour change can support emissions reduction, but behaviours that are not convenient to change are unlikely to shift without changes to policy". A study demonstrated varying attitudes towards environmental measures across different contexts. While voluntary measures like carbon offsetting faced skepticism, there was more willingness to accept regulatory measures, including government intervention through taxation. The study concluded that voluntary approaches alone would be insufficient, emphasizing the need for a diverse policy mix to promote behavioral change in public flying habits. The response of governments "has been to encourage voluntary public behaviour change towards lower carbon lifestyles; an approach that has failed to gain traction in the context of discretionary tourist air travel".
Cities can increase the capability of citizens to make sustainable choices such as by "changing urban form to increase locational and mobility options and providing feedback mechanisms to support socio-behavioural change". Socio-politico-technical feedback processes could "be decisive for climate policy and emissions outcomes". A modal shift away from air transport is complicated by that many people are "used to the current affordability, flexibility and speed of air travel" due to which "passenger acceptance will be a significant barrier to modal shifts and lower cruising speed particularly in wealthy nations". Collective efforts to reduce air-travel-related carbon emissions are much more likely to be successful than isolated attempts.
A 2020 study reported that authors "could not locate quantitative research on large-scale modal shifts and demand reduction in aviation, except during the COVID-19 lockdown."
Related policies have been called "travel demand management" (TDM) policies or "mobility management strategies".
Short-haul flight restrictions
Restricting short-haul flights has a relatively high potential for reducing emissions (and non-emission forcing). One approach or element of such restrictions could be short-haul flight bans:
Improvement of train infrastructure
A shift towards high-speed rail could replace air travel. While improvements in rail travel times "have resulted in reductions in short-haul air travel", substitution results vary. Notably, concurrent "expansion of low-cost carriers has led to a significant increase in total European air traffic". Air travel demand decreased significantly after the entry of the Beijing-Shanghai high-speed rail. Costs of train trips are often higher but can in some cases "be offset by travelling on an overnight train and avoiding the cost of a hotel room".
In studies up to 2022, levels of air traffic reduction from substitution by rail ranged between 7% and 28% – for example, one study estimated that about 17% of intra-European short- and medium-haul traffic can be substituted by rail with an up to 20% increase in travel time. Not considering complementary concurrent measures, another study estimated that air traffic could be reduced by 25% if high-speed rail were available between all major cities. One study from 2005 found there "recently been a rather large reduction of between 34% and 75% in domestic aviation demand in Korea", identifying "the introduction of several new highway services and the fact that Korea Train Express (KTX) began operating a route between Seoul and Daegu in April 2004" as the "two primary causes".
Train connections can reduce feeder flights.
Regional travel
Local holidays can avoid emissions. Boosting or building "travel bubbles" (limited-range tourism) "through other means of transport like train services with landlocked countries" and encouraging more domestic tourism could help in substantial reductions of air travel demand. Long-distance travel can be replaced with travel along short-haul regional bubbles.
A study suggests that a stronger demand for medium- to long-haul air transport is the main driver of the tourism industry's increasing greenhouse gas emissions. A 2014 study notes that the travel sector could compensate for losses from distant-destination travel mitigation, for instance, "by investing in less carbon-intensive (domestic, short-haul) tourism or by raising a small fee on long-haul travel to contribute to a special poverty alleviation fund. It also found that a "reduction in tourist travel distances" has significantly less severe impacts than previously envisioned". It "strongly recommended" that future research examines "impacts of specific policies aimed at reducing the growth of tourism transport demand for long- and medium-haul travel based on the adoption of a more holistic approach and the inclusion of economic aspects in a more systematic manner". Moreover, there also are "negative impacts of the current growth of air transport on the tourism economies in both poor and wealthy countries" as many countries "may attract additional tourists by reducing the distances that people travel", specifically those viably reachable by high-speed rail or other low-carbon modes of transport from domestic and nearby countries.
A study indicates promotion of low-carbon travel markets could play a role and noted that "[l]ong-haul markets are [...] generally much more carbon-intensive than visitors from proximal (nearby) source markets, even though they tend to stay longer and spend more per journey". It also noted that destination country governments could contribute to optimizing the demand mix proactively and that the "current approach toward the tourism market mix is largely passive".
Changes to international conferences
Most international professional or academic conference attendants travel by plane, conference travel is often regarded as an employee benefit as costs are supported by employers. The Tyndall Centre has reported means to change common institutional and professional practices. Environmental impacts of in-person conferences can also be reduced via "multi-site" or "multi-hub hybrid conferences" with "spatially optimized conference hubs".
Air travel infrastructure
Building new or larger airports increase greenhouse gas emissions. A "limit to airport expansion" could suppress demand. Concerning constraints to individual airports' capacities, one study suggests that "airlines would adjust operations within a constrained flight network in such a way as to avoid airports with high delays".
The large expansion in air travel over the last decades has been facilitated by the increased network of airports along with the "relative cheapness of flights (compared to other travel modes), greater incomes and more available leisure time".
Economics
Changes in prices – mainly concurrent increases and decreases in ticket prices – "will impact air transport demand and supply characteristics", making travelers consider alternative travel modes. While demand does not appear to be sensitive to small incremental price changes, "particularly for long-haul and business trips", more significant price increases could significantly suppress demand. High carbon taxes may be needed for shifts to high-speed trains. Distance-based air passenger taxes through increased ticket prices could reduce demand, depending on the tax level and price elasticity. Taxes may be especially effective "if there is a direct link between punishing polluting behaviour and investments that benefit many". Targeted interventions could make not only air travel more expensive but also train tickets cheaper using, for instance, subsidies.
Humans who travel have a "Travel Time Budget (TTB) and Travel Money Budget (TMB)".
Norms, social feedback, psychology, and awareness
Current norms may promote unsustainable behaviors like frequent flying. Air travel is relevant to contemporary social capital generation. (e.g. see standard of living or life activities, interpersonal attraction, social norm, and motivations for travel)
The failure of voluntary policy-independent changes has been partly explained by "contemporary neoliberal western lifestyles" which encourage "unrestrained consumption" of the socioeconomic system's products. The "deeply embedded nature of contemporary tourist air travel in developed societies" has been described as 'air travel addiction' which could be compared to other public health issues and related lobbies. Social media "has been instrumental in creating an interest in frequent air travel". A study notes that declining real cost of air travel "has 'normalized' flying into an everyday activity.
Sustainability education – e.g. about the impacts of aviation, flights and climate change – can also play a role in reducing air travel demand. Moreover, a review finds that if the media stops "uncritical reporting on technology 'solutions'", this would raise feelings of responsibility and if it does "not accept advertisement for air travel", this could reduce demand. There are reports about some implemented bans for advertisements for emissions-intensive products that include cheap short-haul flights.
Information provision, "to encourage and stimulate pro-climate decision-making", and related 'nudging' and social marketing approaches could also play a role. A study outlines potential decision-making or psychological reactions by air travelers "feeling accountable for emissions", including cognitive dissonance.
There are organizations that campaign for targets-based demand management interventions such as removing "the considerable tax breaks the aviation industry receives, through not paying VAT or fuel duty" or "airport expansion" such as UK's AirportWatch and the global Stay Grounded.
Bottom-up voluntary unbeneficial action such as flying less if sustained "could alter social norms can spark collective action and move the needle on policy". It can also alter incentives for top-down decisions including consumer demand and raise expectations for reciprocity as collectively "We punish free riders who don't do their part and reward those who chip in", which could co-trigger some level of further action, for instance from the industry. The Fridays for Future movement prompted "debates regarding the desirability and justifiability of air travel, with evidence of [some subsequent] avoidance and substitution".
Flight shame
In Sweden the concept of "flight shame" or "flygskam" has been cited as a cause of falling air travel. To a small extent, the concept has also spread globally. Swedish rail company SJ AB reports that twice as many Swedish people chose to travel by train instead of by air in summer 2019 compared with the previous year. Swedish airports operator Swedavia reported 4% fewer passengers across its 10 airports in 2019 compared to the previous year despite global growth: a 9% drop for domestic passengers and 2% for international passengers.
Personal carbon allowances
With personal carbon allowances (PCAs), certificates must be used for GHG-intensive activities. If they were implemented, they could also include air travel. According to Sodha, "rationing everyone's flights" – an "individual cap on air travel, that people can trade with each other" – could play a role in climate change mitigation.
In 2021, a study published in Nature Sustainability concluded that PCAs could be a component of climate change mitigation. It found there currently is an open window of opportunity for first trial implementations in climate-conscious technologically advanced countries. PCAs could consist of credit-feedbacks and decreasing default levels of per capita emissions allowances.
A PCA scheme was trialed in the UK with 100 volunteers, showing the technical feasibility of the scheme in 2008. The nature of the traded credits for personal consumption could lead to additional psychology-based impacts when compared to a carbon tax. A rationing framework may reduce air travel in a fair and just way.
Other
Telepresence and remote work: adoption of teleworking, remote working, videoconferencing, and other telepresence technologies, can reduce flight demand.
Restricting the use of private jets
Frequent flyer levies (FFLs)
Prior-travel evaluation: a study suggests many people who took flights for purposes other than vacation considered a large share of their flights to have been of little importance or unnecessary, suggesting "curtailing travel" may be possible by further means. The COVID-19 pandemic illustrated that a significant share of business travel is unnecessary.
Delegation: Bearne suggested that if there is "someone who lives or works nearer to the event or meeting who could go", this could be leveraged to reduce air travel.
Alternative propulsion has limited near-term potential, as commercial availability of such designs is expected only after 2030.
Air travel usage and social impacts
The aviation industry's emissions are projected to continue to rise – and rapidly so – without related climate policy and demand for air travel is projected to quickly return to its pre-COVID-19 pandemic level.
A study found that "[l]ong-term scenarios generally project a steep increase in global travel demand, leading to an rapid rise in emissions", with "[m]ajor driving forces" being "the increasing car use in developing countries and the global growth in air travel".
Demand for air travel across countries and population groups is "closely associated with affluence and lifestyle". While "the share of passenger demand is substantially smaller in the Middle East (9%), Latin America and the Caribbean (5%) and Africa (2%), demand in those regions has been rapidly increasing, for example, growing by 234% in the Middle East between 2007 and 2019". It has been estimated that around 90% of people have never flown and 1% of the current population is responsible for 50% of current emissions from flying. It is estimated that, "at most, 11% of the global population flew in 2018, and only 2%–4% traveled between countries". Total aviation demand in 2019 was almost 1 trillion ton-kilometer equivalent with 78% representing passenger flights and 22% freight.
The ICCT estimates that 3% of the global population take regular flights.
Stefan Gössling of the Western Norway Research Institute estimates 1% of the world population emits half of commercial aviation's CO2, while close to 90% does not fly in a given year.
A study finds that "disadvantaged groups" remain far less likely to be "affected by air travel demand management policies because air travel inequality is still at a very high level". Taxes on air travel would raise fewer fairness concerns than other types of carbon taxes. A study notes that in comparison, kinds of frequent flyer levies or levies on excessive consumption in general have the potential to (more easily or inherently) be "equitable, effective and politically acceptable environmental policy".
In early 2022, the European Investment Bank published the results of its 2021–2022 Climate Survey, showing that 52% of Europeans under 30, 37% of people between 30 and 64 and 25% of people aged 65 and above plan to travel by air for their summer holidays in 2022; and 27% of those under 30, 17% for people aged 30–64 and 12% for people aged 65 and above plan to travel by air to a faraway destination.
See also
Electric aircraft
Hydrogen-powered aircraft
Impact of the COVID-19 pandemic on aviation
Travel during the COVID-19 pandemic
Energy demand management
Environmental psychology
Demand destruction
Marketing
Water demand management
Supply reduction
Modal share
References
Further reading
– includes an overview table of potential interventions
Climate change mitigation
Aviation and the environment
Transportation planning
Sustainable transport
Demand management | Air travel demand reduction | [
"Physics"
] | 3,587 | [
"Physical systems",
"Transport",
"Sustainable transport"
] |
73,186,796 | https://en.wikipedia.org/wiki/Bondarzewia%20kirkii | Bondarzewia kirkii is a species of polypore fungus in the family Russulaceae that is endemic to the beech forests of New Zealand.
Ecology
Bondarzewia kirkii is a parasitic fungus that fruits on the roots of beech trees throughout New Zealand. It appears to be long lived and to fruit on mature trees. It only has been collected from January through March, significantly earlier than most other macrofungi in New Zealand.
External links
Bonzardewia kirkii in Index Fungorum
References
Fungi described in 2019
Fungi of Oceania
Russulales
Fungus species | Bondarzewia kirkii | [
"Biology"
] | 119 | [
"Fungi",
"Fungus species"
] |
73,187,255 | https://en.wikipedia.org/wiki/NGC%202617 | NGC 2617 is a Seyfert galaxy in the equatorial constellation of Hydra. It was discovered on February 12, 1885, by French astronomer Édouard Stephan. In 1888, Danish astronomer J. L. E. Dreyer described it as "extremely faint, very small, 2 very faint stars involved". It is located at an estimated distance of million light years. In the infrared, the galaxy has an angular size of arcminutes.
This is an almost face-on spiral galaxy with a morphological classification of Sc, indicating a spiral galaxy (S) with loosely wound spiral arms (c). In 1992, NGC 2617 was shown to be an extragalactic source of X-ray emission, and in 1996 it was identified as a Seyfert 1.8 galaxy by E. C. Moran and associates. A radio counterpart was found in 1998.
During April 2013, a dramatic outburst was discovered at the core of NGC 2617, and the spectral type was found to have changed to a Seyfert 1. An increase in X-ray emission was observed, followed by an increase in ultraviolet and then infrared luminosity. This event can be modeled by X-ray radiation heating the accretion disk orbiting a supermassive black hole (SMBH) at the center of the galaxy. This was followed by emission at longer wavelengths from the heated disk. An increase in luminosity between 2010 and 2012 may have cleared away dust in the inner part of the disk prior to the outburst, allowing a clearer view and changing the Seyfert type of the galaxy. The SMBH has an estimated mass of .
Additional outbursts were observed from 2016 to 2018, in between deep minima.
References
Further reading
Seyfert galaxies
Spiral galaxies
2608
Discoveries by Édouard Stephan
Hydra (constellation) | NGC 2617 | [
"Astronomy"
] | 370 | [
"Hydra (constellation)",
"Constellations"
] |
73,189,075 | https://en.wikipedia.org/wiki/Koml%C3%B3s%27%20theorem | Komlós' theorem is a theorem from probability theory and mathematical analysis about the Cesàro convergence of a subsequence of random variables (or functions) and their subsequences to an integrable random variable (or function). It's also an existence theorem for an integrable random variable (or function). There exist a probabilistic and an analytical version for finite measure spaces.
The theorem was proven in 1967 by János Komlós. There exists also a generalization from 1970 by Srishti D. Chatterji.
Komlós' theorem
Probabilistic version
Let be a probability space and be a sequence of real-valued random variables defined on this space with
Then there exists a random variable and a subsequence , such that for every arbitrary subsequence when then
-almost surely.
Analytic version
Let be a finite measure space and be a sequence of real-valued functions in and . Then there exists a function and a subsequence such that for every arbitrary subsequence
if then
-almost everywhere.
Explanations
So the theorem says, that the sequence and all its subsequences converge in Césaro.
Literature
Kabanov, Yuri & Pergamenshchikov, Sergei. (2003). Two-scale stochastic systems. Asymptotic analysis and control. 10.1007/978-3-662-13242-5. Page 250.
References
Probability theorems
Theorems in analysis | Komlós' theorem | [
"Mathematics"
] | 308 | [
"Theorems in mathematical analysis",
"Mathematical analysis",
"Theorems in probability theory",
"Mathematical problems",
"Mathematical theorems"
] |
73,189,382 | https://en.wikipedia.org/wiki/Drawing%20tower | A drawing tower produces a fine glass filament by drawing a glass preform. The tip of the preform is heated to melting temperature and then a strand of molten material is pulled downward. Industrial drawing towers range in height from 30 to 45 meters. A drawing tower is used in the production of optical fiber, for example for fiber-optic communication cables. The preform is a multi-layered cylinder typically 20 cm in diameter, and 2 m long.
References
Fiber optics | Drawing tower | [
"Materials_science",
"Engineering"
] | 97 | [
"Materials science stubs",
"Materials science"
] |
73,190,005 | https://en.wikipedia.org/wiki/Xanthatin | Xanthatin, or (3aR,7S,8aS)-7-methyl-3-methylidene-6-[(E)-3-oxobut-1-enyl]-4,7,8,8a-tetrahydro-3aH-cyclohepta[b]furan-2-one (C15H18O3) is a major bioactive compound found in the leaves of the Xanthium strumarium (Asteracae) plant. It is classified as a natural sesquiterpene lactone. Xanthatin is believed to have anti-inflammatory, anti-tumour, anti-microbial, and anti-parasitic properties hence it is being researched for potential use in treatment of cancer and autoimmune diseases. While it has been used in traditional medicine for decades, its mechanisms and modern use haven’t been fully understood yet.
History
Traditional usage
Xanthium strumarium L. (Asteracae) has been used thousands of years as Chinese herbal medicine (named ). Its leaves have shown anti-inflammatory, analgesic, anti-asthmatic, anti-microbial, and diuretic properties in an herbal supplement before it was known that xanthatin was the main bioactive compound.
In 1963, the fruits of Xanthium strumarium L. were listen in the Pharmacopoeia of the People’s Republic of China.
Modern usage
In 1975, xanthatin was isolated from the leaves of the Xanthium strumarium and it was determined to be the predominant compound in these plant leaves.
In the 21st century, in vitro, and in vivo research is performed on xanthatin showing promising results in anti-tumour, anti-inflammatory and antibacterial applications on various cell lines.
Structure
Xanthatin is a sesquiterpene lactone. It consists of three isoprene units with a lactone ring attached resulting in a sesquiterpene derivative of C15H18O3 compared to the usual C15H18. During the synthesis of Xanthatin it was reported that a multitude of functional groups could be derived from the same synthetic pathway showing much promise for other medicinal candidates.
Synthesis
Xanthatin was first reported to be enantioselective synthesized by Shishido. Further developments have shown that the synthesis can be adapted to form other xanthanolide analogues, which could be of medicinal interest. Many reaction steps are involved in the synthesis of Xanthatin a general overview is given with details below based on the research of Bergman et al.
Methyl-furoate (1) is the commercially available starting compound used. To form the ketone group and prepare seven membered ring formation asymmetric catalytic cyclopropanation, ozonolysis is used followed by allylation, realdolation and lactonization. An apple type reaction a chemoselective reduction of the aldehyde formed is used to form 2.
Knochel’s protocol is used to provoke sp3-sp3 coupling with tert-butyl-2-(bromomethyl)acrylate after which the compound is used as a substrate in a ring closing metathesis reaction under influence of a Grubbs II catalyst. Giving rise to the bicyclic sesquiterpene skeleton of Xanthatin (3).
In order to form Xanthatin, more steps have to be executed. Due to the chair conformation of 3 it is sterically favored to form a single stereomere by execution of a Ene-reaction. The alcohol or ester that is formed can be removed by presence of CuCN and RLi in a SN2 like fashion.
The final steps include the formation of a α-exo-methylene group at the C-3 position. The α-exo-methylene group introduction is a difficult process since the molecule is already prone to unwanted side reactions. In order to achieve this a method involving base induced hydroxymethylation by gaseous formaldehyde following a pivalylation introduced a methanol group at the C-3. The tert-butylester needs to be stepwise hydrolysed towards an aldehyde. When the molecule was introduced to a strong base the desired α-exo-methylene-γ-butyrolactone group was formed. A Makaiyama aldol condensation with trimethyl(prop-1-en-2-yloxy)silane is added for the complete synthesis of Xanthatin and its derivatives
Mechanism of action
The exact mechanism of action of xanthatin is not exactly known. However, it was found that it works through various molecular pathways which all lead to apoptosis. One of these proposed pathways is that xanthatin inhibits the nuclear factor-kappa B (NF-κB) transcription factor which is critical for controlling cell proliferation. This would reduce inflammation and suppress growth of cancer cells. Another study suggests the same with addition of induced endoplasmic reticulum (ER) stress in glioma (brain cancer) which also leads to apoptosis. Oxidative stress is another pathway in which xanthatin works. It binds to selenocysteine (Sec) residue of TrxR enzyme which leads to irreversible inhibition. This leads to oxidative stress which can induce apoptosis.
Metabolism
Xanthatin is classified as a sesquiterpene lactone, which can help to determine the metabolism of xanthatin, because metabolism of xanthatin is unknown. There are studies about the metabolism of different sesquiterpene lactones. Most of the sesquiterpene lactones are BCS II classified, which means that they have high permeability and low water solubility. After they entered the gastrointestinal tract, the absorption is poorly due to their pH sensitivity. Xanthatin contains a α-methylene-γ-butyrolactone, which is the main location of metabolism in other sesquiterpene lactones. However, there are metabolic differences in similar compounds with this reactive group. But phase I reactions such as oxidation, (de)hydration, hydroxylation, sequential desaturation, and epoxidation are found in different sesquiterpene lactones. (Acetyl)cysteine conjugation, methylation, glutathione conjugation are common phase II reactions in sesquiterpene lactones.
Indications
In traditional medicine, some symptoms may occur at high doses. These may include vomiting, tremors, weak pulse, a loss of appetite, and convulsions.
Efficacy
Traditionally, Xanthatin has been used in folk medicine. Xanthatin is a bioactive compound and possesses anti-inflammatory, analgesic, anti-asthmatic, anti-microbial, diuretic properties. However, scientific research of xanthatin is limited.
Scientific studies show that xanthatin can be anti-proliferative against various tumour cells in-vitro and in-vivo through inhibition and induce apoptosis. Xanthatin also consists of an anti-inflammatory activity by inhibiting PGE2 synthesis and 5-lipoxygenase activity.
Side effects
Research data about side effects has not been reported due to lack of human data.
Toxicity
At high concentrations, xanthatin exhibits hepatotoxic effects, causing liver damage in mice. Xanthatin has been reported to promote apoptosis. Thus, this will also include cell proliferation of healthy tissue. In vitro, and in vivo research has shown that it can also cause DNA damage in regular cells.
References
Sesquiterpenes
Lactones
Ketones | Xanthatin | [
"Chemistry"
] | 1,649 | [
"Ketones",
"Functional groups"
] |
73,190,019 | https://en.wikipedia.org/wiki/Four-dimensional%20Chern%E2%80%93Simons%20theory | In mathematical physics, four-dimensional Chern–Simons theory, also known as semi-holomorphic or semi-topological Chern–Simons theory, is a quantum field theory initially defined by Nikita Nekrasov, rediscovered and studied by Kevin Costello, and later by Edward Witten and Masahito Yamazaki. It is named after mathematicians Shiing-Shen Chern and James Simons who discovered the Chern–Simons 3-form appearing in the theory.
The gauge theory has been demonstrated to be related to many integrable systems, including exactly solvable lattice models such as the six-vertex model of Lieb and the Heisenberg spin chain and integrable field theories such as principal chiral models, symmetric space coset sigma models and Toda field theory, although the integrable field theories require the introduction of two-dimensional surface defects. The theory is also related to the Yang–Baxter equation and quantum groups such as the Yangian.
The theory is similar to three-dimensional Chern–Simons theory which is a topological quantum field theory, and the relation of 4d Chern–Simons theory to the Yang–Baxter equation bears similarities to the relation of 3d Chern–Simons theory to knot invariants such as the Jones polynomial discovered by Witten.
Formulation
The theory is defined on a 4-dimensional manifold which is a product of two 2-dimensional manifolds: , where is a smooth orientable 2-dimensional manifold, and is a complex curve (hence has real dimension 2) endowed with a meromorphic one-form .
The field content is a gauge field . The action is given by wedging the Chern–Simons 3-form with :
Restrictions on underlying manifolds
A heuristic puts strong restrictions on the to be considered. This theory is studied perturbatively, in the limit that the Planck constant . In the path integral formulation, the action will contain a ratio . Therefore, zeroes of naïvely correspond to points at which , at which point perturbation theory breaks down. So may have poles, but not zeroes. A corollary of the Riemann–Roch theorem relates the degree of the canonical divisor defined by (equal to the difference between the number of zeros and poles of , with multiplicity) to the genus of the curve , giving
Then imposing that has no zeroes, must be or . In the latter case, has no poles and a complex torus (with a 2d lattice). If , then is the complex projective line. The form has two poles; either a single pole with multiplicity 2, in which case it can be realized as on , or two poles of multiplicity one, which can be realized as on . Therefore is either a complex plane, cylinder or torus.
There is also a topological restriction on , due to a possible framing anomaly. This imposes that must be a parallelizable 2d manifold, which is also a strong restriction: for example, if is compact, then it is a torus.
Surface defects and field theories
The above is sufficient to obtain spin chains from the theory, but to obtain 2-dimensional integrable field theories, one must introduce so-called surface defects. A surface defect, often labelled , is a 2-dimensional 'object' which is considered to be localized at a point on the complex curve but covers which is fixed to be for engineering integrable field theories. This defect is then the space on which a 2-dimensional field theory lives, and this theory couples to the bulk gauge field .
Supposing the bulk gauge field has gauge group , the field theory on the defect can interact with the bulk gauge field if it has global symmetry group , so that it has a current which can couple via a term which is schematically .
In general, one can have multiple defects with , and the action for the coupled theory is then
with the collection of fields for the field theory on , and coordinates for .
There are two distinct classes of defects:
Order defects, which introduce new degrees of freedom on the defect which couple to the bulk gauge field.
Disorder defects, where the bulk gauge field has some singularities.
Order defects are easier to define, but disorder defects are required to engineer many of the known 2-dimensional integrable field theories.
Systems described by 4d Chern–Simons theory
Spin chains
Six-vertex model
Eight-vertex model
XXZ Heisenberg spin-chain
Integrable field theories
Gross–Neveu model
Thirring model
Wess–Zumino–Witten model
Principal chiral model and deformations
Symmetric space coset sigma models
Master theories of integrable systems
4d Chern–Simons theory is a 'master theory' for integrable systems, providing a framework that incorporates many integrable systems. Another theory which shares this feature, but with a Hamiltonian rather than Lagrangian description, is classical affine Gaudin models with a 'dihedral twist', and the two theories have been shown to be closely related.
Another 'master theory' for integrable systems is the anti-self-dual Yang–Mills (ASDYM) system. Ward's conjecture is the conjecture that in fact all integrable ODEs or PDEs come from ASDYM. A connection between 4d Chern–Simons theory and ASDYM has been found so that they in fact come from a six-dimensional holomorphic Chern–Simons theory defined on twistor space. The derivation of integrable systems from this 6d Chern–Simons theory through the alternate routes of 4d Chern–Simons theory and ASDYM in fact fit into a commuting square.
See also
Chern–Simons theory
Integrable system
Classical Gaudin model
Anti-self-dual Yang–Mills equations
External links
nLab page
References
Quantum field theory
Integrable systems | Four-dimensional Chern–Simons theory | [
"Physics"
] | 1,215 | [
"Integrable systems",
"Quantum field theory",
"Theoretical physics",
"Quantum mechanics"
] |
68,787,170 | https://en.wikipedia.org/wiki/Where%20the%20Giant%20Sleeps | Where the Giant Sleeps is a 2007 children's picture book by Mem Fox and illustrated by Vladimir Radunsky. A bedtime book, it was published by Harcourt, Inc., and it is about a giant and the creatures that inhabit it sleeping and preparing for sleep as seen through a telescope by a child who, as it turns out, is dreaming.
Reception
A brief review of Where the Giant Sleeps in The New York Times wrote: "A dreamlike landscape - houses, trees, hills and pastures - makes the form of a sleeping giant. Small readers will enjoy putting the details together, and Radunsky's gouache illustrations seem to glow with starlight". Kirkus Reviews wrote: "Casting dim moonlight over drowsy forms made with cloudy edges and soft colors, the artist expertly captures the poem’s tone and makes the slide down into dreamland well-nigh inevitable".
Where the Giant Sleeps has also been reviewed by the following publications: Publishers Weekly, Booklist, School Library Journal, Horn Book Guides, Library Media Connection, Magpies, and The Center for Children’s Literature.
References
External links
Library holdings of Where the Giant Sleeps
Australian picture books
2007 children's books
Picture books by Mem Fox
Giants in popular culture
Sleep in fiction | Where the Giant Sleeps | [
"Biology"
] | 261 | [
"Behavior",
"Sleep in fiction",
"Sleep"
] |
68,787,817 | https://en.wikipedia.org/wiki/Boletus%20shiyong | Boletus shiyong is a species of porcini-like fungus native to Yunnan Province in Southwestern China, where it grows under Picea spp., Pinus densata, and Quercus aquifolioides. It is very closely related to Boletus quercophilus and Boletus nobilissimus; less closely to Boletus aereus.
The epithet shiyong is the Hanyu Pinyin transcription of the fungus's Mandarin epithet, "edible", originally used to translate the epithet of Boletus edulis.
References
shiyong
Fungi of China
Fungi described in 2013
Fungus species | Boletus shiyong | [
"Biology"
] | 130 | [
"Fungi",
"Fungus species"
] |
68,788,098 | https://en.wikipedia.org/wiki/List%20of%20investigational%20attention%20deficit%20hyperactivity%20disorder%20drugs | This is a list of investigational attention deficit hyperactivity disorder drugs, or drugs that are currently under development for clinical use in the treatment of attention deficit hyperactivity disorder (ADHD) but are not yet approved.
Chemical/generic names are listed first, with developmental code names, synonyms, and brand names in parentheses.
This list was last comprehensively updated in September 2021. It is likely to become outdated with time.
Under development
Preregistration
ATT-377 Combination treatment of Methylphenidate ER, cyproheptadine
TRN-110 [extended-release] undefined mechanism / extended-release form of an undisclosed drug
Phase 3 clinical trials
Centanafadine [sustained-release] (centanafadine SR, CTN-SR, EB-1020, EB-1020 SR) serotonin–norepinephrine–dopamine reuptake inhibitor
Dexmethylphenidate [controlled release] (CTX-1301) norepinephrine–dopamine reuptake inhibitor
Edivoxetine (LY-2216684) norepinephrine reuptake inhibitor
Molindone [extended-release] (AFX-2201, EN-1733A, molindone XR, SPN-810, SPN-810M, Zalvari) antipsychotic / dopamine D2 receptor antagonist and serotonin receptor modulator (e.g., serotonin 5-HT2B and 5-HT2A receptor antagonist) specifically under development for impulsive aggression in ADHD
Serdexmethylphenidate (KP-484) dexmethylphenidate prodrug / norepinephrine–dopamine reuptake inhibitor
Solriamfetol (ADX-N05, ARL-N05, JZP-110, SKL-N05; Sunosi) norepinephrine–dopamine reuptake inhibitor
Phase 2 clinical trials
CX-717 ampakine / AMPA receptor modulator
Mazindol [controlled release] (NLS-0, NLS-1, NLS-10, NLS-13, NLS-2, Nolazol, Quilience) serotonin–norepinephrine–dopamine reuptake inhibitor
PDC-1421 (BLI-1005) norepinephrine reuptake inhibitor
Phase 1 clinical trials
AFX-2401 "neurotransmitter modulator"
Atomoxetine [oral solution] (TAH-9922) norepinephrine reuptake inhibitor
Dextroamphetamine [abuse-deterrent immediate-release] (ADAIR) norepinephrine–dopamine releasing agent
Preclinical/research
Atomoxetine [oral suspension] norepinephrine reuptake inhibitor
Dextroamphetamine [controlled release] (CTX-1302) norepinephrine–dopamine releasing agent
NNI-351 DYRK1A inhibitor and "neurogenesis enhancer"
No development reported
AFI-002 undefined mechanism
Altropane (123-I Altropane®, [123I]-E-IACFT Injection, [123I]NAV5001, CFT, Iodine-123-E-IACFT Injection, NAV-5001, O-587) dopamine reuptake inhibitor / single-photon emission-computed tomography enhancer
Amphetamine [oral abuse-deterrent immediate-release] (ADAIR) norepinephrine–dopamine releasing agent
Bavisant (BEN-2001, JNJ-1074, JNJ-31001074) histamine H3 receptor antagonist
BCWP-E003 undefined mechanism
BLI-1008 undefined mechanism
Brilaroxazine (RP-5000, RP-5063) atypical antipsychotic / dopamine receptor partial agonist and serotonin receptor modulator
Cannabidiol/gabapentin (Cannbleph) cannabinoid receptor modulator and gabapentinoid
Ciforadenant (CPI-444, V-81444) adenosine A2A receptor antagonist
CM-4612 (CM-ADHD, CM-AT, CM-PK) gastrointestinal/pancreatic enzyme replacement therapy
CRD-102 undefined mechanism
Dasotraline (DSP-225289, SEP-225289, SEP-0225289, SEP-225289-HCI, SEP-289) serotonin–norepinephrine–dopamine reuptake inhibitor
Dextroamphetamine [abuse-resistant] (PF-08, PFR 08001, PFR08026) – norepinephrine–dopamine releasing agent
Dextroamphetamine sulfate [modified release capsules] (HLD-900, HLD-100) norepinephrine–dopamine releasing agent
Dopamine [intranasal] (DopaMat, MPP-18) dopamine receptor agonist
Eltoprazine (DU-28853) serotonin 5-HT1A and 5-HT1B receptor agonist
Fasoracetam [co-crystallised] (AEVI-004, NFC-1) racetam / metabotropic glutamate receptor modulator
GTS-21 (DMXB-A, DMXB-A sustained release, DMXB-A-SR) α7 nicotinic acetylcholine receptor agonist
Guanfacine [once-daily] (Guanfacine Carrier Wave, SPD-547) α2-adrenergic receptor agonist
IPX-233 (IPX233 ER C0003, IPX233-C0001, IPX233-C0002, IPX233-T0001, IPX233-T0002) central nervous system stimulant
Masupirdine (M1, M1 of SUVN-502, SUVN-502, SVN-502) serotonin 5-HT6 receptor antagonist
Methylphenidate [extended-release/abuse-resistant] (COL-171) norepinephrine–dopamine reuptake inhibitor
Methylphenidate [fast dissolve tablet] [Samyang Holdings Biopharmaceuticals] norepinephrine–dopamine reuptake inhibitor
Methylphenidate [transdermal system] (SHX-009) norepinephrine–dopamine reuptake inhibitor
Methylphenidate/naltrexone (AVK-001) norepinephrine–dopamine reuptake inhibitor and opioid receptor antagonist
Nic-12 undefined mechanism
NLS-2 antianaemic / heavy metal / iron replacement
PD-3044 dopamine reuptake inhibitor
Pitolisant (tiprolisant; BF-2.649, BF-2649, Ozawade, Wakix) histamine H3 receptor antagonist
R-Sibutramine metabolite ((+)-desmethylsibutramine, (+)-didesmethylsibutramine, R-DDMS, R-desmethylsibutramine, R-didesmethylsibutramine) serotonin–norepinephrine–dopamine reuptake inhibitor
Selegiline [transdermal] (Emsam) monoamine oxidase B inhibitor
SKL-13865 (SKL-ADHD) norepinephrine–dopamine reuptake inhibitor
Sofinicline (A-422894.0, ABT-894) α4β2 nicotinic acetylcholine receptor modulator
SPN-811 undefined mechanism
Taminadenant (NIR-178, PBF-509) adenosine A2A receptor antagonist
Research programmes
Ampakines / AMPA receptor modulators [RespireRx] (CX-516, CX-614, CX-707, CX-929, CX-1501, CX-1763, CX-1796, CX-1837, CX-1846, CX-1942, CX-2007, CX-2076)
Cannabis extracts [Cannabis Science] (CBIS GAP-001, CBIS LC-001, CBIS OBLD-001, CBIS OCD-001, CBIS PC-001, CBIS PPC-001, CBIS PS-001, CBIS SD-001, CBIS SSA-001, CBIS-OS-001, CBIS-PTSD-001, CS NEURO 1, CS-S/BCC-1, CS-TATI-1) cannabinoid receptor modulators
Norepinephrine reuptake inhibitors / adrenergic receptor antagonists [Pfizer] (NRI-022, NRI-193, WAY-253203, WAY-256805, WAY-260022, WAY-315193, WAY-318068)
Pim2 / PolyPhetamine [ITL Pharma]
Subtype-selective glutamate NMDA receptor modulators / glutamate NR2B receptor modulators [Novartis]
Not under development
Development discontinued
ABT-418 nicotinic acetylcholine receptor agonist
Amphetamine [transdermal patch] [Noven/Takeda] norepinephrine–dopamine releasing agent
Ampreloxetine (TD-9855) norepinephrine reuptake inhibitor
AR-08 adrenergic receptor agonist
Aripiprazole (Abilify, Abilify Maintena, Abilify MyCite, Abilitat, Ao Pai, Aripiprazole depot, Aripiprazole ECER tablets, Arlemide; OPC-14597, OPC-14597 IMD, OPC-31) atypical antipsychotic / dopamine receptor partial agonist and serotonin receptor modulator
AZD-5213 histamine H3 receptor antagonist
Bifemelane (SON-216) monoamine oxidase inhibitor and weak norepinephrine reuptake inhibitor
Bradanicline (ATA-101, TC-0569, TC-5619, TC-5619-238) α7 nicotinic acetylcholine receptor agonist
Brexpiprazole (Rexulti, Rxulti; Lu-AF41156, OPC-34712, OPDC-34712) atypical antipsychotic / dopamine receptor partial agonist and serotonin receptor modulator
Buspirone [transdermal] (BuSpar Patch) serotonin 5-HT1A receptor partial agonist, other actions
Cipralisant (GT-2331; Perceptin) histamine H3 receptor antagonist
CX-516 (1-BCP, AMPAlex, BDP-12, SPD-420) ampakine / AMPA receptor modulator
CX-1739 ampakine / AMPA receptor modulator
Donepezil (Aricept, Aricept D, Aricept Dry Syrup, Aricept Evess, Aricept ODT, Aricept SR, Donepezil SR, E-2020, E-2022, Eranz) acetylcholinesterase inhibitor
Droxidopa (3,4-dihydroxyphenylserine, 3,4-threo-DOPS, L-threo-dihydroxyphenylserine, L-threodops, Northera, threo-dopaserine, threo-DOPS) prodrug of norepinephrine / adrenergic receptor agonist
Fasoracetam (AEVI-001, LAM-105, MDGN-001, NFC-1, NS-105) racetam / metabotropic glutamate receptor modulator
Ispronicline (AZD-3480, RJR-1734, TC 01734, TC-1734, TC-1734-112) α4β2-nicotinic acetylcholine receptor agonist
KP-106 (dextroamphetamine prodrug oral film) norepinephrine–dopamine releasing agent
Lauflumide (flmodafinil, bisfluoromodafinil; NLS-14, NLS-4) weak dopamine reuptake inhibitor, possibly other actions
Manifaxine (BW-1555U88, GW-320659) norepinephrine–dopamine reuptake inhibitor
Mecamylamine (Inversine, Tridmac) nicotinic acetylcholine receptor antagonist
MEM-68626 5-HT6 receptor antagonist
Metadoxine [sustained/extended-release] (pyridoxine-pyrrolidone carboxylate, pyridoxine pidolate; MDX, metadoxine SR, MG-01CI) serotonin 5-HT2B receptor antagonist, GABA modulator, other actions
Methylphenidate [transdermal patch] (TAH-9901) norepinephrine–dopamine reuptake inhibitor
MK-0249 histamine H3 receptor antagonist
Modafinil (AFT-801, Alertec, Attenace, CN-801, CRL-40476, Modasamil, Modasonil, Modavigil, Modiodal, Provigil, Sparlon, Vigil) weak dopamine reuptake inhibitor, possibly other actions
Nicotine/opipramol (ND-0801; opipramol/nicotine) tricyclic antidepressant / monoamine and sigma receptor modulator and nicotinic acetylcholine receptor agonist
NLS-8(melafenoxate) undefined mechanism
NS-2359 (GSK-372475) serotonin–norepinephrine–dopamine reuptake inhibitor
OPC-64005 serotonin–norepinephrine–dopamine reuptake inhibitor
ORG-26576 (ORG26576) ampakine / AMPA receptor modulator
PF-3654746 (PF-03654746) histamine H3 receptor antagonist
Phacetoperane (NLS-3) methylphenidate analogue / central nervous system stimulant / norepinephrine–dopamine reuptake inhibitor (?)
Pirepemat (IRL-752) "cortical enhancer" / serotonin 5-HT7 receptor antagonist and α2C-adrenergic receptor antagonist, other actions
Pozanicline (A-87089.0, ABT-089) α4β2 nicotinic acetylcholine receptor agonist
SEP-225432 serotonin–norepinephrine–dopamine reuptake inhibitor
SGS-742 (CGP-36742, DVD-742, Lu-AE58479, SGS-742) GABAB receptor antagonist
SPD-483 undefined mechanism
SPD-554 (Guanfacine Carrier Wave project) α2-adrenergic receptor agonist
SPI-339 (NEO-339) undefined mechanism
TAK-137 AMPA receptor potentiator
TC-6683 (AZD 1446, TC-6683) α4β2 nicotinic acetylcholine receptor agonist
Tipepidine [sustained-release] (TS-141) GIRK inhibitor
Vortioxetine (Brintellix, LU-AA21004, LuAA 21004, Trintellix) antidepressant / serotonin reuptake inhibitor and serotonin receptor modulator
Research programmes
Potassium channel modulators [Astellas Pharma/Icagen]
Formal development never or not yet started
Dopamine precursors (L-phenylalanine, L-tyrosine, L-DOPA (levodopa))
Clinically used drugs
Approved drugs
Norepinephrine–dopamine releasing agents
Amphetamine (Adzenys ER, Adzenys XR-ODT, Dyanavel XR, Evekeo, Evekeo ODT)
Dextroamphetamine (Dexedrine, Zenzedi, Xelstrym)
Fenethylline (Biocapton, Captagon, Fitton) amphetamine and theophylline prodrug discontinued/no longer used
Levoamphetamine (Cydril) discontinued/no longer used
Lisdexamfetamine (Elvanse, Tyvense, Venvanse, Vyvanse) dextroamphetamine prodrug
Methamphetamine (dextromethamphetamine; Desoxyn, Methampex)
Mixed amphetamine salts (Adderall, Adderall XR, Mydayis)
Pemoline (Betanamin, Ceractiv, Cylert, Tradon) withdrawn/discontinued due to toxicity
Norepinephrine–dopamine reuptake inhibitors
Dexmethylphenidate (Focalin, Focalin XR)
Methylphenidate (Adhansia XR, Aptensio XR, Benjorna, Biphentin, Concerta, Cotempla XR-ODT, Daytrana, Equasym, Foquest, Jornay PM, Metadate, Metadate CD, Metadate ER, Methydur, MethyPatch, Oradur, QuilliChew ER, Quillivant XR, Ritalin, Ritalin SR)
Serdexmethylphenidate/dexmethylphenidate (Azstarys)
Norepinephrine reuptake inhibitors
Atomoxetine (tomoxetine; Strattera)
Viloxazine [extended-release] (Qelbree)
α2-Adrenergic receptor agonists
Clonidine (Catapres, CloniBID, Clonicel, Jenloga XR, Kapvay)
Guanfacine (Connexyn, Intuniv, Intuniv XR, Tenex)
Off-label drugs
Bupropion (Wellbutrin) norepinephrine–dopamine reuptake inhibitor and nicotinic acetylcholine receptor antagonist
Modafinil (Provigil) weak dopamine reuptake inhibitor, possibly other actions
Reboxetine (Edronax) norepinephrine reuptake inhibitor
Serotonin–norepinephrine reuptake inhibitors (e.g., venlafaxine (Effexor), duloxetine (Cymbalta))
Tricyclic antidepressants (e.g., desipramine (Norpramin) – norepinephrine reuptake inhibitor)
See also
List of investigational drugs
References
Further reading
External links
AdisInsight - Springer
Attention deficit hyperactivity disorder drugs, investigational
Dynamic lists
Experimental psychiatric drugs | List of investigational attention deficit hyperactivity disorder drugs | [
"Chemistry"
] | 4,188 | [
"Drug-related lists"
] |
68,788,124 | https://en.wikipedia.org/wiki/Cat%20Nap%20%28Yuly%20book%29 | Cat Nap is a 2016 children's picture book by Toni Yuly. It is about a sleepy cat having to play hide-and-seek with a boisterous kitten.
Reception
A review in Booklist of Cat Nap wrote, "Yuly's artwork is as sprightly as the tale, which milks all the humor from a situation that mirrors the experiences of a younger and older sibling." Kirkus Reviews was also positive, writing, "The simple text relies on repetition to stress Cat’s futile plight, while bold illustrations use flat, bright colors, basic shapes, and definitive black outlines to amplify Kitten’s successful pursuit."
Cat Nap has also been reviewed by Publishers Weekly, School Library Journal, and Horn Book Guides.
References
External links
Library holdings of Cat Nap
2016 children's books
American picture books
Children's books about cats
Sleep in fiction | Cat Nap (Yuly book) | [
"Biology"
] | 180 | [
"Behavior",
"Sleep in fiction",
"Sleep"
] |
68,788,883 | https://en.wikipedia.org/wiki/Proxmark3 | Proxmark3 is a multi-purpose hardware tool for radio-frequency identification (RFID) security analysis, research and development. It supports both high frequency (13.56 MHz) and low frequency (125/134 kHz) proximity cards and allows users to read, emulate, fuzz, and brute force the majority of RFID protocols.
Originally created by Jonathan Westhues and published as open-source hardware, it was later picked up by a community of developers who significantly improved both hardware and software in comparison with the original version. Proxmark3 gathered a large community of security researchers investigating RFID access control systems, who expand and maintain the project while using it in their own research. The original Proxmark3 hardware platform served as the basis for new device versions, including commercial ones.
Technical specification
Proxmark3 is based on field-programmable gate array (FPGA) technology, which allows the implementation of high-performance low-level analog signal processing, modulation and demodulation. A separate microcontroller processes demodulated frames. Such setup potentially allows any RFID protocol to be implemented in Proxmark3's software.
Antennas
2 independent antenna circuits are used for low frequencies (LF) 125 kHz and 134 kHz, and high frequency (HF) 13.56 MHz. Initially, both antennas were connected with a shared 4-pin Hirose USB connector, which was unreliable at times. Subsequent revisions have opted to use a separate connector for each antenna.
ADC
8-bit Analog-to-digital converter (ADC) receives an analog signal from the antenna circuit, digitizes it and outputs the digital signal to the FPGA.
FPGA
Field-programmable gate array does both the low-level modulation when transmitting data from CPU and demodulation when receiving a signal from an ADC. It can process various modulations such as on–off keying (OOK), amplitude-shift keying (ASK), etc. The FPGA works in two ways: as reader generating electromagnetic field for cards, or as card waiting for reader field.
CPU
The ARM microcontroller is responsible for the protocol part. It encodes and decodes the frames (Manchester, Miller, etc) and performs more advanced functions. The CPU can reply back to the FPGA after signal handling, thus implementing the transport layer. The CPU also manages the USB communication with the PC client application.
Flash memory
Flash memory is used to store firmware. The early versions of Proxmark3 only had 64 kB of flash memory, but as firmware developed that became scarce and versions with 512 kB appeared.
The firmware itself consists of ARM code and an FPGA image (which is loaded by the ARM). The FPGA communicates with the ARM through either its SPI port (the ARM is the master) or its generic SSP. The SPI is used for FPGA configuration. The SSP is used for data sent over the air.
Software
At the time Proxmark3 was developed, SDR was a hard to access technology. For that reason a split FPGA/MCU architecture was designed: an FPGA handles low-level functionality such as modulation/demodulation, while a microcontroller cares for the high-level functionality (command-line interface, protocol encoding/decoding, etc). While the FPGA/MCU architecture is technically outdated, it remained unchanged throughout hardware revisions. This allowed different versions to use the same firmware and resulted in a large code-base. However, with time the Proxmark3 codebase became increasingly fractured and hardware instabilities started to appear. As a result, some implementations refine and optimize the code (for example Proxmark3 RDV4), while others use the original Proxmark3 codebase (for example Proxmark3 EVO).
Proxmark3 software is divided into three parts:
PC client (application layer) – PC application which calls the Proxmark3 functions. It is used to display data, analyze the signal and manage Proxmark3. Subsequently, in newer Proxmark3 versions a mobile app can be used to control the Bluetooth-connected device.
CPU firmware (transport layer) – ARM firmware that manages protocol messages, formats and queues. It also provides CLI tools.
FPGA firmware (physical layer) – Xilinx Spartan II firmware is responsible for the DSP: modulating/demodulating of signals.
Older firmware used USB HID protocol to connect the client to the Proxmark3. It was not possible to stream the received samples in real-time to the PC. CPU received a command from the client, executed it and stored the result in the memory buffer. The client had to send a new command to retrieve the CPU buffered data. New firmware versions use CDC serial interface to communicate with the client.
Signal samples may be handled by the PC client, it can plot received data to assist in analyzing unknown signals.
Community
Since Proxmark3's release in 2007 several RFID enthusiasts have been extending its functionality. Proxmark3 community has seen rapid growth after the release of firmware supporting the ISO/IEC 14443-A standard and appearing successful attacks on Mifare Classic. The Proxmark3 forum (registration required) became one of the main hubs for RFID system vulnerability discussion frequented by security researchers focusing on electronic access control (EAC) systems. The Proxmark community also houses developers of other RFID research tools: for example LibNFC. The community Discord server was later created to host both text and voice discussions on the topic of EAC system security. It had about 3000 members at the end of 2021.
Researches used Proxmark3
Mifare Classic cards attacks:
Darkside attack (Nijmegen/Oakland Group, 2009)– recovering at least one key from any sector of the card. Works for every card, takes a long time. Using mfoc (Mifare Offline Cracker) tool from libnfc stack.
Nested attack (Nicolas T. Curtois, 2009) – If one sector is encrypted with a known key, other sectors are crackable in a short amount of time. There is also the updated version of this attack – Hardnested. Using mfcuk (Mifare Classic universal toolkit) tool from libnfc stack.
Mifare Classic paper:
A practical attack on the MIFARE Classic
Mifare DESFire paper:
An investigation of possible attacks on the MIFARE DESFire EV1 smartcard used in public transportation
HID iClass papers:
Heart of darkness – exploring the uncharted backwaters of HID iCLASS security
Hitag paper:
Gone in 360 Seconds: Hijacking with Hitag2
Megamos paper:
Dismantling Megamos Crypto: Wirelessly Lockpicking a Vehicle Immobilizer
NFC papers:
Practical attacks on NFC enabled cell phones
Radio-frequency identification
Open-source hardware
Computer-related introductions in 2007
References | Proxmark3 | [
"Engineering"
] | 1,458 | [
"Radio-frequency identification",
"Radio electronics"
] |
68,789,708 | https://en.wikipedia.org/wiki/DOTAM | DOTAM (also known as TCMC) is an organic compound used as a chelator much like its carboxylic acid analog DOTA. A derivative with a reactive linking group of para-isothiocyanatobenzyl attached to the cyclen ring is also of interest as a bifunctional chelator (BFC).
References
Macrocycles
Acetamides
Octadentate ligands | DOTAM | [
"Chemistry"
] | 88 | [
"Organic compounds",
"Macrocycles"
] |
68,789,736 | https://en.wikipedia.org/wiki/Lenglart%27s%20inequality | In the mathematical theory of probability, Lenglart's inequality was proved by Èrik Lenglart in 1977. Later slight modifications are also called Lenglart's inequality.
Statement
Let be a non-negative right-continuous -adapted process and let be a non-negative right-continuous non-decreasing predictable process such that for any bounded stopping time . Then
References
Citations
General sources
Stochastic differential equations
Articles containing proofs
Probabilistic inequalities | Lenglart's inequality | [
"Mathematics"
] | 96 | [
"Theorems in probability theory",
"Probabilistic inequalities",
"Articles containing proofs",
"Inequalities (mathematics)"
] |
68,789,789 | https://en.wikipedia.org/wiki/Balanced%20lethal%20systems | In evolutionary biology, a balanced lethal system is a situation where recessive lethal alleles are present on two homologous chromosomes. Each of the chromosomes in such a pair carries a different lethal allele, which is compensated for by the functioning allele on the other chromosome. Since both these lethal alleles end up in the gametes in the same frequency as the functioning alleles, half of the offspring, the homozygotes, receive two copies of a lethal allele and therefore die during development. In such systems, only the heterozygotes survive.
Balanced lethal systems appear to pose a challenge to evolutionary theory, since a system so wasteful should be rapidly eliminated through natural selection and recombination. Instead, it has become fixed in various species all over the tree of life.
Mechanism
The exact mechanism behind balanced lethal systems remains unknown. Prior to the availability of efficient DNA sequencing methods, it was already known that the lethality in such a system was caused by homozygosity of a certain chromosome pair.
One theory is that, in the case of the Triturus genus, the balanced lethal system is a remnant of an ancient sex-determination system. One of the chromosomes of the pair that contains the system is longer than the other, which is also the case for the actual sex chromosomes. In this theory, deleterious mutations accumulated on the non-recombining part of the Y-chromosome (Muller’s ratchet). Then, two distinct Y-chromosomes, both with different lethal mutations, co-segregated in a population. Since sex-determination in many cold-blooded vertebrates is potentially dependent on temperature, a shift away from chromosomal sex determination occurred. This system favoured the sex reversal of females, which eventually led to the loss of the original X-chromosome. A mutation on another chromosome later restored the even sex ratio, and gave rise to a new male-heterogametic system. A major restriction for this theory is that it could only evolve in species where temperature-dependent sex-reversal is possible. Since balanced lethal systems are found in many species where this is not the case, this theory does not provide a general explanation for how such a system evolved.
Another theory is that balanced lethal systems are collapsed supergenes. Supergenes are linked genes that are inherited as a single unit. Genes can only be inherited together when recombination is suppressed, for example when selection favors certain allelic combinations. The lack of recombination can lead to the accumulation of mutations in both supergene clusters and this could generate a feedback loop: when natural selection favours heterozygotes, few homozygotes reproduce. This lack of reproduction leads to the accumulation of deleterious alleles. When lethal mutations become fixed on both supergene alleles, homozygotes are no longer viable, resulting in a balanced lethal system.
Prevalence
A well known balanced lethal system is the one fixed in the genus Triturus (containing the crested and the marbled newts). Each of the homologous chromosomes of pair 1 (1A and 1B) has a different recessive deleterious allele on a non-recombining section of the chromosome. Therefore, only heterozygotes are viable since these deleterious alleles are compensated for by the functioning allele on the other homologue. As a result half of all offspring stop growing and die during early development.
The offspring of Triturus carnifex for example, have either a viable heterozygous genotype (1A/1B) or one of the homozygous embryonic lethal genotypes: fat-tailed (1A/1A) or slim-tailed (1B/1B).
See also
Balancer chromosome
Recessive lethals
Northern crested newt
Hermann Joseph Muller
Linkage disequilibrium
References
Further reading
Evolutionary biology
Classical genetics | Balanced lethal systems | [
"Biology"
] | 798 | [
"Evolutionary biology"
] |
68,789,829 | https://en.wikipedia.org/wiki/Maria%20Benktzon | Maria Benktzon (born 1946) is a Swedish designer, she is known for industrial design with human factors. She is a co-founder of Ergonomi Design Gruppen which later became Veryday, an industrial design consultancy located in Stockholm. The company aimed to design improved everyday objects for the home and work. In November 2016, Veryday joined forces with McKinsey & Company, and today operates under the name "McKinsey Design."
Biography
Maria Benktzon was born in 1946 in Nyköping, Sweden. and studied at the Konstfack University of Arts, Crafts and Design in Stockholm.
In 1968, Benktzon was at a conference and saw a talk given by Victor Papanek concerning design for social good, which inspired her user-centred and inclusive approach to design. In 1969, Maria graduated and joined Henrik Wahlforss’ group, established as Ergonomidesign. In 1972, Maria Benktzon and collaborated with in-depth ergonomic and physiological studies to investigate the grip of knives and bread saws, among other things. Their efforts were able to raise the standards of facilities for the disabled regarding for accessibility and functionality. They designed kitchenware, cutlery and personal hygiene tools; in order to allow people with limited hand strength or movement to continue using these items.
Much of Maria Benktzon’s work has been recognised as landmarks of inclusive design. One of the first products resulting from her collaboration on studies with Sven Eric Juhlin was the world’s first angled kitchen knife, designed for Gustavsberg in 1973. In 1978, they designed the revolutionary Knork Fork, which acts as a knife and fork and was aimed at people incapable of using two hands to eat. In the same year, they also designed the Eat and Drink Plate.
Other notable design objects include the Scandinavian Airlines (SAS) coffee pot (1987), various Tupperware knives, Doro phones, and Ejendals work gloves. Maria's work is in various public museum collections, including at the Museum of Modern Art (MoMA), the Cooper Hewitt, Smithsonian Design Museum, the Röhsska Museum, and the Nationalmuseum.
Maria has received various awards recognising her innovative, ergonomic and consumer-friendly designs of household objects. She was presented with the Ron Mace “Designing for the 21st century” award in 2000 and a lifetime achievement award at the Include Conference in London in 2005. In 2023, Maria received the Lifetime Achievement Award at the DesignEuropa Awards, organised by the European Union Intellectual Property Office (EUIPO).
References
Living people
1946 births
Swedish industrial designers | Maria Benktzon | [
"Engineering"
] | 542 | [
"Design stubs",
"Design"
] |
68,789,853 | https://en.wikipedia.org/wiki/Stochastic%20Gronwall%20inequality | Stochastic Gronwall inequality is a generalization of Gronwall's inequality and has been used for proving the well-posedness of path-dependent stochastic differential equations with local monotonicity and coercivity assumption with respect to supremum norm.
Statement
Let be a non-negative right-continuous -adapted process. Assume that is a deterministic non-decreasing càdlàg function with and let
be a non-decreasing and càdlàg adapted process starting from . Further, let be an - local martingale with and càdlàg paths.
Assume that for all ,
where .
and define . Then the following estimates hold for and :
If and is predictable, then ;
If and has no negative jumps, then ;
If then ;
Proof
It has been proven by Lenglart's inequality.
References
Stochastic differential equations
Articles containing proofs
Probabilistic inequalities | Stochastic Gronwall inequality | [
"Mathematics"
] | 185 | [
"Theorems in probability theory",
"Probabilistic inequalities",
"Articles containing proofs",
"Inequalities (mathematics)"
] |
68,790,094 | https://en.wikipedia.org/wiki/Hyperspectral%20Imager%20for%20the%20Coastal%20Ocean | The Hyperspectral Imager for the Coastal Ocean (HICO) was a hyperspectral earth observation sensor that operated on the International Space Station (ISS) from 2009 to 2014. HICO collected hyperspectral satellite imagery of the Earth's surface from the ISS.
HICO was a pathfinder or proof-of-concept mission for hyperspectral imaging of the oceans, particularly for optically complex coastal waters. The dataset collected by HICO serves as an example dataset for future hyperspectral satellite missions such as PACE.
HICO was mounted directly on the ISS rather than on a separate unmanned satellite platform (i.e., distinct from the MODIS sensor mounted on Aqua and Terra satellites and from SeaWiFS mounted on OrbView-2 aka Seastar satellite). As such, HICO was tasked to collect images of certain regions in sync with the daytime orbit path of the ISS. Further, its data record may contain some gaps in time for operational tasks on board the ISS such as spacewalks and docking.
History
HICO was developed by the United States Office of Naval Research. The sensor was launched on September 10, 2009, from the Tanegashima Space Center in Japan as payload for the ISS on the H-2B-304 rocket (including HTV-1 transfer vehicle). It was installed on September 24, 2009, onto the Japanese Experiment Module Exposed Facility of the Kibo Laboratory (Japanese Kibo complex) of the ISS by two Expedition-20 engineers, ESA astronaut Frank De Winne and NASA astronaut Nicole Stott. HICO was installed concurrently with the RAIDS/Remote Atmospheric and Ionospheric Detection System: together these two systems are referred to as the “HICO and RAIDS Experiment Payload (HREP or HREP-RAIDS).” HICO Collected over 10,000 images during its operating lifetime.
Financial support came from the United States Office of Naval Research, the United States Department of Defense, and later from the International Space Station Program.
In summer 2013 HICO data became publicly available and remain freely accessible today.
HICO stopped collecting data in September 2014 when radiation from a solar flare damaged its computer. Attempts to restart the computer were unsuccessful. The last image date and official end of operations was September 13, 2014.
After the end of its lifetime, HICO and RAIDS Experiment Payload (HREP) was removed from the ISS on August 3, 2018, on the SpaceX CRS-15 Dragon space capsule after its July–August 2018 resupply mission. The Dragon's trunk section burned up during re-entry, disposing of the HICO instrument and other contents. The flight that offloaded HICO was the fourth ever round-trip cargo flight with a reused Dragon capsule.
Technical specifications and data products
Spectral coverage and resolution
HICO uses 128 spectral bands from approximately 353 nm to 1080 nm wavelengths at 5.7 nm spectral resolution (band centers 5.7 nm apart). Data from wavelengths less than 400 nm and greater than 900 nm are not recommended for analysis; 400-900 nm data are higher quality. A 10 nm smoothing filter is applied to wavelengths 400 to 745 nm and a 20 nm filter is applies to wavelengths 746 to 900 nm.
Spatial coverage and resolution
HICO pixels are approximately 90 meters in spatial resolution. Each full scene covers approximately a 42 by 192 km rectangle (varying with altitude and angle). High latitude regions of the Earth are not covered. The ISS accomplishes about sixteen 90-minute orbits per day, and the location of the track for orbit moves to the west as Earth rotates. The ISS orbit tracks over the same area on the ground about every three days, including nighttime overpasses. However, HICO imaging was limited to collect only one scene per orbit, resulting in about seven to eight daylight scenes per day, often spatially scattered throughout the world.
Radiometric resolution
HICO data have a signal-to-noise ratio of greater than 200-to-1 for water-penetrating wavelengths and assuming 5% albedo. The sensor had high sensitivity in the blue wavelengths and full coverage of water-penetrating wavelengths.
Temporal coverage and resolution
HICO collected satellite imagery from September 25, 2009, to September 13, 2014. A maximum of eight daylight scenes were collected per day. In any specific coastal region where scenes were imaged, temporal resolution is patchy. For example, over Chesapeake Bay on the United States east coast, 101 scenes were collected over the entire 5-year mission, and 16 scenes were imaged during the calendar year 2012.
Data products
HICO datasets, like other hyperspectral satellite datasets, are large in terms of data volume. For example, one HICO scene requires 120 MB to 700 MB of disk space (depending on format and compression). Data are available from NASA Ocean Color Web in HDF file format (similar to netCDF).
Similar sensors
Deutsches Zentrum fur Luft–und Raumfahrt German Aerospace Center (DLR) Earth Sensing Imaging Spectrometer (DESIS), installed on the International Space Station. This sensor is the most comparable to HICO because it is both hyperspectral and mounted on the ISS.
Other hyperspectral satellite sensors
(partial list)
Hyperion, launched aboard the Earth Observing-1 (EO-1) spacecraft in 2000
Compact High Resolution Imaging Spectrometer (CHRIS), on PROBA-1 in 2001
Scanning Imaging Absorption Spectrometer for Atmospheric Chartography (SCIAMACHY) on ENVISAT from 2002 to 2012
PRecursore IperSpettrale della Missione Applicativa (PRISMA), launched 2019 by the Italian Space Agency
Advanced Hyperspectral Imager (AHSI), onboard China's GaoFen-5 satellite in 2018
Hyperspectral Imaging Satellite (HySIS) launched from India in 2018
HyperScout instruments launched on nanosatellites
(Planned) Ocean Color Instrument (OCI) on the Plankton, Aerosols, Clouds, and ocean Ecosystems (PACE) satellite
Other Earth science instruments on the ISS
(partial list)
ISS-RapidScat, which operated from 2014 to 2016.
Total and Spectral Solar Irradiance Sensor 1 (TSIS-1), which was installed in 2013.
SAGE III, installed in 2017.
Lightning Imaging Sensor (LIS), installed in 2017.
Global Ecosystem Dynamics Investigation (GEDI) full-waveform LIDAR, installed in 2018.
ECOsystem Spaceborne Thermal Radiometer Experiment on Space Station (ECOSTRESS) instrument, which was delivered to the ISS on the same mission that offloaded HICO in 2018.
Orbiting Carbon Observatory 3 (OCO-3), installed in 2019.
Applications
Phytoplankton ecology in general, such as which types of phytoplankton are present in a region of the ocean based on the signature of their pigments and the colors of light those pigments absorb.
Detection of harmful algal blooms (HABs) by recognizing unique wavelengths of light being emitted by specific types of plankton blooming in large quantities. For example, HICO imagery has been used in the detection of cyanobacteria blooms in inland waters (such as Lake Erie and Pinto Lake, California and blooms of the ciliate Mesodinium rubrum in Long Island Sound.
Mapping bathymetry of shallow waters.
Dissolved matter photochemistry in coastal waters.
Water quality monitoring, including variables such as chlorophyll-a and suspended particulate matter.
Maps of terrain, vegetation type, and bottom type.
Characterization of the Deepwater Horizon Oil Spill in April 2010, including collecting images from the area around the explosion sites and from nearby marshes to identify unpolluted water, oil-water mixtures, and emulsified oil strands.
See also
Earth observation satellite
Hyperspectral imaging
Imaging spectroscopy
International Space Station
Kibo (ISS module)
Ocean color
Plankton, Aerosol, Cloud, ocean Ecosystem
Scientific research on the International Space Station
References
External links
HICO data access via NASA ocean color website
Hyperspectral Data for Land and Coastal Systems, training by NASA ARSET, including use of HICO data
Remote sensing
Satellite imaging sensors
Earth sciences
Space science
Satellites
NASA
Piggyback mission
Components of the International Space Station
Earth observation satellite sensors
Oceanography
Kibo (ISS module) | Hyperspectral Imager for the Coastal Ocean | [
"Physics",
"Astronomy",
"Environmental_science"
] | 1,705 | [
"Hydrology",
"Applied and interdisciplinary physics",
"Outer space",
"Oceanography",
"Space science",
"Satellites"
] |
68,790,217 | https://en.wikipedia.org/wiki/European%20Journal%20of%20Taxonomy | The European Journal of Taxonomy is a peer-reviewed open access scientific journal for descriptive taxonomy of living and fossil eukaryotes, covering subjects in zoology, botany, and palaeontology. It is supported by the EJT Consortium, a group of European natural history institutes, which fully funds the publication. Therefore, the journal is free for both authors and readers (diamond open access).
History
The journal was initiated by a task force of people from the European Distributed Institute of Taxonomy network. The first article was published on 9 September 2011. In October 2015, the Consortium of European Taxonomic Facilities endorsed the journal.
Several older journals have been merged into the European Journal of Taxonomy:
Journal of Afrotropical Zoology
Bulletin de l'Institut Royal des Sciences Naturelles de Belgique, Entomologie
Bulletin de l'Institut Royal des Sciences Naturelles de Belgique, Biologie
Bulletin de l'Institut Royal des Sciences Naturelles de Belgique, Sciences de la Terre
Steenstrupia
Zoologische Mededelingen
Abstracting and indexing
The journal is abstracted and indexed in:
Biological Abstracts
BIOSIS Previews
CAB Abstracts
Current Contents/Agriculture, Biology & Environmental Sciences
Science Citation Index Expanded
The Zoological Record
According to the Journal Citation Reports, the journal has a 2020 impact factor of 1.372.
References
External links
English-language journals
Continuous journals
Academic journals established in 2011
Systematics journals | European Journal of Taxonomy | [
"Biology"
] | 286 | [
"Systematics journals",
"Taxonomy (biology)"
] |
68,792,288 | https://en.wikipedia.org/wiki/Surface%20Laptop%20Studio | The Surface Laptop Studio is a 2-in-1 convertible laptop developed by Microsoft. It was announced by the company alongside the Surface Go 3 and Surface Pro 8, Surface Duo 2 and several Surface accessories at their Surface Event on September 22, 2021. The device is a new form factor featuring a dual-pivoting screen that flips into tablet mode. The laptop shipped with Windows 11.
On 4 February, 2022, Microsoft announced the general availability for organizations across industries in the UAE of its Surface Laptop Studio and Surface Pro 8.
Microsoft announced its replacement, the Surface Laptop Studio 2 in September 2023.
Features
Windows 11 operating system
Intel Tiger Lake 11th Gen Core i5 or Core i7 processor
Intel Iris Xe graphics, Nvidia GeForce RTX 3050 Ti (Consumer), or NVIDIA RTX A2000 (Enterprise) GPU with 4 GB of GDDR6 RAM
120 Hz refresh rate and Dolby Vision support
16 or 32 GB of LPDDR4X RAM
256 GB to 2 TB NVME SSD storage
2 Thunderbolt 4 USB-C ports
Configurations
Hardware
A new three-position display with a complete overhaul.
14.4-inch touch display with 2400 x 1600 pixels (201 ppi) and a 3:2 aspect ratio
The first Surface Laptop to contain 2 USB-C ports with Thunderbolt 4.
It comes with a removable SSD.
Precision Haptic touchpad
Software
The Surface Laptop Studio will be powered by the new Windows 11 operating system with a 30-day trial of Microsoft 365. Consumer models will get the Home edition and the business models will get the Pro edition of the operating system. The device also supports Windows Hello login using biometric facial recognition.
Timeline
References
Studio
2-in-1 PCs
Computer-related introductions in 2021 | Surface Laptop Studio | [
"Technology"
] | 369 | [
"Crossover devices",
"2-in-1 PCs",
"Computing stubs",
"Computer hardware stubs"
] |
68,792,348 | https://en.wikipedia.org/wiki/Neptunium%28VII%29%20oxide-hydroxide | Neptunium(VII) oxide-hydroxide is a chemical compound which has neptunium in its highest oxidation state of +7. This compound reacts with basic salts such as potassium hydroxide to form neptunates (NpO53-) and water.
NpO2(OH)3 + 3KOH → K3NpO5 + 3H2O
Neptunium(VII) oxide-hydroxide is stable in an alkaline solution, however, it is slowly reduced to Np(VI) in an acidic solution. In water, it forms a greenish solution. This compound decomposes slowly to an oxidized solid.
Production
Neptunium(VII) oxide-hydroxide is produced by the oxidation of Np(VI) in alkaline solution with ozone, then neutralized with nitric acid to precipitate out the neptunium(VII) oxide-hydroxide.
References
Neptunium compounds
Hydroxides | Neptunium(VII) oxide-hydroxide | [
"Chemistry"
] | 203 | [
"Inorganic compounds",
"Bases (chemistry)",
"Hydroxides",
"Inorganic compound stubs"
] |
68,793,989 | https://en.wikipedia.org/wiki/Solid-phase%20reversible%20immobilization | Solid-phase reversible immobilization, or SPRI, is a method of purifying nucleic acids from solution. It uses silica- or carboxyl-coated paramagnetic beads, which reversibly bind to nucleic acids in the presence of polyethylene glycol and a salt. A common application of SPRI technology is purifying samples of DNA amplified by PCR for sequencing reactions:.
Use in nucleic acid purification
SPRI beads are paramagnetic beads coated with silica or carboxyl groups. When the beads are resuspended in solutions with high concentrations of polyethylene glycol and salts, they are capable of binding reversibly to nucleic acids. This binding is size selective, in that longer polymers of nucleic acids bind more efficiently than shorter ones. A SPRI purification typically includes the following steps:
SPRI beads in a solution of polyethylene glycol and sodium chloride are mixed with a sample of nucleic acids. The nucleic acids bind to the beads.
The mixture is placed in a magnetic field, which separates the nucleic-acid bound beads from the solution.
The solution is removed and the beads are washed multiple times with 80% ethanol in water.
The beads are allowed to dry to remove residual ethanol.
The beads are removed from the magnetic field and resuspended in water or an elution buffer, which releases the nucleic acids from the beads.
The mixture is once again placed in a magnetic field, separating the beads from the solution.
The solution, which now contains the purified nucleic acids, is removed and used for downstream applications.
See also
Nucleic acid methods
DNA sequencing
Solid-phase extraction
References
Nucleic acids | Solid-phase reversible immobilization | [
"Chemistry"
] | 360 | [
"Biomolecules by chemical classification",
"Nucleic acids"
] |
68,795,873 | https://en.wikipedia.org/wiki/Andrew%20Crowther%20Hurley | Andrew Crowther Hurley (1926–1988) was a quantum chemist and mathematician who was elected a Fellow of the Australian Academy of Science in 1972.
He was a student of the University of Melbourne and obtained First Class Honours B Sc in Theoretical Physics and theory of Statistics. He received his Bachelor of Arts (Honours) in 1947 and his Bachelor of Science in 1948.
He received his Master of Arts degree in March 1949 for his thesis 'Finite Rotation Groups and Crystal Classes in Four Dimensions', receiving First Class Honours and first place.
In 1950 he moved to Trinity College, Cambridge, where he studied for his PhD in theoretical physics under the supervision of Paul Dirac. After one term, he transferred to the Department of Theoretical Chemistry under the supervision of John Lennard-Jones, and also interacted with S. Francis Boys, George G. Hall and John Pople. He worked on Moffitt's method of atoms in molecules and
introduced the method of 'intra-atomic correlation correction' using the rather poor computational facilities available, which limited the calculations to small molecules.
In 1953 he joined the Commonwealth Scientific and Industrial Research Organisation, Chemical Physics Section, and remained there until his death in 1988. He was an expert on group theory and its uses in quantum chemistry.
In 1963, he wrote a monograph on the 'Electronic Theory of Small Molecules' for the series 'Theoretical Chemistry' published by Academic Press.
References
1926 births
1988 deaths
20th-century Australian chemists
Fellows of the Australian Academy of Science
Computational chemists
CSIRO people
Australian mathematicians
University of Melbourne alumni
Alumni of Trinity College, Cambridge | Andrew Crowther Hurley | [
"Chemistry"
] | 319 | [
"Computational chemistry",
"Theoretical chemists",
"Computational chemists"
] |
68,796,562 | https://en.wikipedia.org/wiki/Daniele%20Dini | Daniele Dini is an Italian/British Mechanical Engineer. He is a Professor of Tribology at Imperial College London, where he is Head of the Tribology Group. Tribology is the science and engineering of friction, lubrication and wear.
Education
Dini received an M.Eng. degree in Mechanical Engineering from the Politecnico di Bari, Italy in 2000, He then studied for a D.Phil. in the Department of Engineering Science at the University of Oxford, which he obtained in 2004. His D.Phil. research was performed under the supervision of Professor David Hills.
Research and career
Dini is currently the Shell-Royal Academy of Engineering Chair in Complex Engineering Interfaces. Previously, he was an Engineering and Physical Sciences Research Council Established Career Fellow. Dini has published over 250 peer-reviewed papers in the field of tribology. According to Google Scholar, his research has been cited over 6000 times and he has a h-index of 43. He is an expert in the modelling and simulation of tribological systems across scales. Dini was promoted to full Professor in 2017, his inaugural lecture was entitled 'Releasing friction's potential'. In the same year, he succeeded Professor Hugh Spikes as Head of the Tribology Group.
He is an Assistant Editor for the Elsevier journal International Journal of Solids and Structures and is on the International Advisory Editorial Board for Tribology International. He is a Co-Director of both the Shell University Technology Centre (UTC) for Fuels and Lubricants and the SKF UTC, which are based in the Department of Mechanical Engineering at Imperial College London. He is also currently Director of Research for the Department of Mechanical Engineering at Imperial College London.
Honours and awards
Dini is the recipient of a number of awards, including: the Tribology Bronze Medal (IMechE, 2004); the Jacob Wallenberg Foundation Award (Royal Swedish Academy of Engineering Sciences, 2007); three best paper awards: Thomas Bernard Hall Prize (IMechE, 2008 and 2010) and the Kenneth L. Johnson Award (ASME, 2012); Teaching Excellence in Engineering Education (Imperial College London, 2014). He was the recipient of the prestigious EPSRC Established Career Fellowship, awarded in 2016. The strong links of his group with industrial partners was recognised through the Imperial College President’s Award and Medal for Excellence in External Collaboration and Partnerships in 2017. He received the Donald Julius Groen Prize from the IMechE in 2019. In 2022, Dini was presented with the inaugural Peter Jost Tribology Award from the International Tribology Council at the 7th World Tribology Congress. Dini received the Tribology Silver Medal from the IMechE in 2022.
In 2014, Dini was elected as a Fellow of the Institution of Mechanical Engineers (FIMechE). In 2021, he was also elected as a Fellow of the Society of Tribologists and Lubrication Engineers (FSTLE) and a Fellow of the Royal Academy of Engineering (FREng).
References
External links
Fellows of the Royal Academy of Engineering
Fellows of the Institution of Mechanical Engineers
British mechanical engineers
Tribologists
Alumni of the University of Oxford
Academics of Imperial College London
Living people
Year of birth missing (living people) | Daniele Dini | [
"Materials_science"
] | 663 | [
"Tribology",
"Tribologists"
] |
68,796,711 | https://en.wikipedia.org/wiki/Rural-Urban%20gradient | The Rural-Urban gradient is a gradient that is used to describe how Anthropocene effects affect their surroundings and how they compare to areas less affected by Anthropocene effects. Effects such as but, not limited to disturbance, change in biota, pollution, and landscape modification. Mainly used in the context of ecosystem services, it has also been used to describe biodiversity along the gradient, as well as behavioral change.
Research
Individual research on the topic is often done by taking multiple samples along a transect from a city center and working outwards. At first, research mainly focused on characteristics involved in land cover structures, the biota of the rural-urban areas and socio-economic structures. However, nowadays research also focuses on many ecosystem services, as well as on biodiversity and evolution.
Ecosystem services
In ecosystem services, rural-urban gradients have shown Anthropocene effects affect their surroundings in multiple ways. For example, research has shown that energy consumption increases with increases population and industrialization. As of now, there is no clear pattern on how ecosystem services are affected by the rural-urban gradient, as it still differs widely between different cities and is dependent on other factors.
Biodiversity
In biodiversity, the rural-urban gradient is sometimes also used to describe the species richness distribution along the gradient. It is known that for most groups of organisms when urbanization is high, species richness decreases. However, when urbanization is at a low to medium level, species richness tends to increase. These are mostly suburban, low-density housing and there are several reasons why the species richness tends to be higher there. For instance, the large presence of private gardens. In these gardens, a great floral diversity exists, largely mostly existing of non-native plants. This, combined with the combined size of all the gardens, create a large, diverse floral area, attracting more fauna than the more urbanized cores of cities. In return, this also creates a greater species richness than both the more urbanized city cores, as well as the rural lands further away from the city.
Another factor of biodiversity on the rural-urban gradient is the effect of invasive and introduced species. With an increase in human activity comes a greater introduction of non-native species. This, combined with research that traffic corridors help to disperse non-native species, make that non-native species also follow a rural-urban gradient, with the highest concentration in the cities and lower concentrations as you go outwards from the city.
In evolution
The rural-urban gradient is also studied in the light of evolution. Research on the common sparrow (Passer domesticus) has shown that populations along a rural-urban gradient can also genetically differentiate from one another over relatively small distances. In contrast, research on the black-headed gull (Chroicocephalus ridibundus) has shown that this genetic differentiation does not always appear along a rural-urban gradient, as the research did not show any significant difference between the genetic make-up of urban and rural populations.
Behavior
In behavioral biology, the rural-urban gradient has mainly been studied in the context of songbirds. Research on European blackbirds (Turdus merula) has shown that there is a significant variation of songs of the European blackbird along a rural-urban gradient. This is probably to avoid the song from being masked by the background noises. However, since the different populations are not isolated, it is unclear whether this is an evolutionary change or part of behavioral plasticity.
References
Urban economics
Urban planning
Anthropology | Rural-Urban gradient | [
"Engineering"
] | 718 | [
"Urban planning",
"Architecture"
] |
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