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64,342,838 | https://en.wikipedia.org/wiki/Traditional%20serrated%20adenoma | Traditional serrated adenoma is a premalignant type of polyp found in the colon, often in the distal colon (sigmoid, rectum). Traditional serrated adenomas are a type of serrated polyp, and may occur sporadically or as a part of serrated polyposis syndrome. Traditional serrated adenomas are relatively rare, accounting for less than 1% of all colon polyps. Usually, traditional serrated adenomas are found in the distal colon and are usually less than 10 mm in size.
Histopathology
Traditional serrated adenomas are characterized by ectopic crypts, pseudostratification, and a villous pattern with stretched nuclei.
Epidemiology
Usually found in individuals over the age of 50 years, traditional serrated adenomas affect men and women equally. The overall prevalence of traditional serrated adenomas is less than 1% of the general population. Traditional serrated adenomas are the least common type of serrated polyps found in the colon, accounting for 5% of serrated colon polyps.
References
Digestive system neoplasia
Histopathology | Traditional serrated adenoma | [
"Chemistry"
] | 237 | [
"Histopathology",
"Microscopy"
] |
64,343,101 | https://en.wikipedia.org/wiki/Ganoderma%20sinense | Ganoderma sinense is a black to purplish-black or dark brown laccate species of Ganoderma found in China, Japan and Taiwan growing on decaying wood of broad-leaved trees and pine stumps. It is used in traditional Asian medicine, where it is known as zizhi (紫芝, purple Ganoderma) in Chinese.
Taxonomy
Ganoderma sinense was erected as a species in 1979 by J.D. Zhao, L.W. Hsu, and X.Q. Zhang, distinguishing it from Ganoderma dimidiatum (formerly G. japonicum) by morphology.
One recent genetic study of two dozen samples collected in China and identified as G. sinense and G. japonicum by morphology showed all samples were the same species, G. sinense. The 20 of these identified as G. sinense showed a high variance in morphological features. Other studies have suggested that G. sinense and G. japonicum are the same species, based on their high sequence similarity in ITS data. However, because DNA samples collected in Japan under G. japonicum'''s revised name, G. dimediatum, were not available to test and compare to G. sinense, the authors believe is too early to determine that G. dimediatum and G. sinense are indeed synonyms.
Description
The basidiocarp is annual, stipitate, and corky–woody.
The pileus (cap) is semicircular and measures and is 9.2–1.2 cm thick in nature. When cultivated, it measures 2.5–6.5 by 3.5–12 cm and is 0.5–1.5 cm thick. The upper surface of the cap is usually purplish black to black or dark brown, laccate, concentrically sulcate or not, radially rugose, margin often subtruncated.
The pore surface is pale brown to dark brown, with grey-brown tubes up to 1.4 cm long. There are 5-6 pores per millimetre, circular, 50–180 μm in diameter, with dissepiments 40–160 μm thick.
The stipe is 6–19 cm long and 0.5–1.0 cm thick, lateral, dorsolateral or eccentric, cylindrical or flattened: the same color as the pileus and also laccate.
Context tissue is 1–5 mm thick, uniformly brown or red brown near the tube layer or with whitish streaks and patches near the cutis. The hyphal system is trimitic, with generative hyphae 3–5 μm in diameter, hyaline, thin-walled, with clamp connections. Skeletal hyphae measure 4.5–7 μm in diameter, and are golden brown in 5% KOH solution and are dextrinoid in Molder's reagent. Ligative hyphae are 1–2.5 μm in diameter, thick-walled, and much branched.
Basidiospores measure 10.5–13.5 by 7–9 μm including endosporium, and 8–9 by 5.5–7. μm excluding. The myxosporium is ovoid and brown with a dark brown eusporium bearing few and thick echinulae, overlaid by a hyaline myxosporium, truncate or not at the apex. Basidia are not seen. Cutis hymeniodermic elements are 20–60 by 4–8 μm, clavate and amyloid in Melzer's reagent.
Uses G. sinense has been used in traditional Chinese medicine since ancient times, appearing in the Shennong Ben Cao Jing, written in the third century CE. It also appears in the 11th century CE materia medica, Ben Cao Gang Mu, by Song dynasty physician Tang Shenwei, among others.G. sinense has wide applications in traditional Chinese medicine, as it is believed to strengthen the body's immune system and disease response while regulating metabolism and normalizing organ function. Diseases treated by G. sinense involve respiratory, circulatory, digestive, nervous, endocrine and immune systems, including internal, external, gynecological, pediatric and dermatological diseases. It is also believed to be useful for platelet-aggregation and as an anti-thrombotic, hepatic-protective, antioxidant, anti-aging, anti-inflammatory, anti-tumor and anti-radiation agent.
In 2010, a G. sinense'' polysaccharide tablet was approved by China's State Food and Drug Administration for use as an adjunctive therapeutic drug for treating leukopenia and hematopoietic injury caused by concurrent chemo/radiation therapy during cancer treatment.
References
sinense
Fungus species | Ganoderma sinense | [
"Biology"
] | 1,019 | [
"Fungi",
"Fungus species"
] |
64,343,520 | https://en.wikipedia.org/wiki/HD%201690 | HD 1690 is a giant star with an orbiting exoplanet companion in the constellation of Cetus. It has an apparent visual magnitude of 9.19, which is too faint to be visible to the naked eye. The distance to this system is approximately 2,570 light years, and it is drifting further away with a radial velocity of +18.2 km/s. HD 1690 has no known companion star, making it a single star system.
This is an evolved K-type giant star with a stellar classification of K1 III. It has 1.18 times the mass of the Sun and, at the estimated age of 6.7 billion years (two billion years older than the Sun), it has expanded to 16 times the Sun's radius. The surface metallicity of HD 1690 (the abundance of elements more massive than helium) is 30% that of the sun. The Hipparcos parallax data have resulted in a distance determination of just , but more recent data from Gaia data have placed HD 1690 much farther from the Sun at .
Planetary system
In 2010, a team of astronomers led by astronomer C. Moutou of the High Accuracy Radial Velocity Planet Searcher performed a radial-velocity analysis that detected a gas giant planet in orbit around HD 1690.
The planet HD 1690 b has a very eccentric (far from circular) orbit; its orbital eccentricity is 0.64. This eccentricity suggests that its mass is at least six times that of Jupiter, classifying it as a super-Jupiter. Other planets in the HD 1690 system are unlikely unless they are located on unstable crossing orbital paths.
References
K-type giants
Planetary systems with one confirmed planet
Cetus
Durchmusterung objects
1690
1692
J00211332-0816521 | HD 1690 | [
"Astronomy"
] | 361 | [
"Cetus",
"Constellations"
] |
64,344,766 | https://en.wikipedia.org/wiki/Kalafungin | Kalafungin is a substance discovered in the 1960s and found to act as a broad-spectrum antibiotic in vitro. It was isolated from a strain of the bacterium Streptomyces tanashiensis.
It is not known to be marketed anywhere in the world.
References
Antibiotics | Kalafungin | [
"Biology"
] | 59 | [
"Antibiotics",
"Biocides",
"Biotechnology products"
] |
64,345,118 | https://en.wikipedia.org/wiki/HAT-P-26 | HAT-P-26 is a K-type main-sequence star located about away in the constellation of Virgo. A survey in 2015 did not find any stellar companions in orbit around it, although a red dwarf companion with a temperature is suspected on wide orbit.
Nomenclature
The designation HAT-P-26 indicates that this was the 26th star found to have a planet by the HATNet Project.
In August 2022, this planetary system was included among 20 systems to be named by the third NameExoWorlds project. The approved names, proposed by a team from Puerto Rico, were announced in June 2023. HAT-P-26 is named Guahayona and its planet is named Guataubá, after figures from Taíno mythology.
Planetary system
In 2010 a transiting hot Neptune planet was detected. The transiting planet HAT-P-26b was detected by the HATNet Project using telescopes located in Hawaii and Arizona. The planet is likely formed by pebble accretion mechanism.
The transmission spectrum of HAT-P-26b was taken in 2015, with the best fit favouring either a cloudless atmosphere or an atmosphere with a low-lying cloud deck. The atmospheric composition of the planet was measured in 2019, and a water vapor volume fraction of 1.5% was detected. HAT-P-26 is carbon depleted, with a C/O ratio constrained to less than 0.33. Also, the planet's atmosphere contains light metal hydrides. The measured planetary temperature is equal to 563 K.
In 2023, the atmosphere of the planet was found to contain water vapor at a temperature of .
A 2019 study detected transit-timing variations (TTVs) of HAT-P-26b, the cause of which was unclear at that time. With more data by 2023, it was suggested that the TTVs may be caused by a second planet in the system. In 2024, a candidate second planet, about twice the size of Earth and slightly farther from the star than planet b, was detected by transit in TESS data, but requires further observations to be fully confirmed.
Notes
References
Virgo (constellation)
K-type main-sequence stars
Planetary systems with one confirmed planet
Planetary transit variables
Guahayona | HAT-P-26 | [
"Astronomy"
] | 460 | [
"Virgo (constellation)",
"Constellations"
] |
64,345,252 | https://en.wikipedia.org/wiki/The%20Fractal%20Dimension%20of%20Architecture | The Fractal Dimension of Architecture is a book that applies the mathematical concept of fractal dimension to the analysis of the architecture of buildings. It was written by Michael J. Ostwald and Josephine Vaughan, both of whom are architecture academics at the University of Newcastle (Australia); it was published in 2016 by Birkhäuser, as the first volume in their Mathematics and the Built Environment book series.
Topics
The book applies the box counting method for computing fractal dimension, via the ArchImage software system, to compute a fractal dimension from architectural drawings (elevations and floor plans) of buildings, drawn at multiple levels of detail. The results of the book suggest that the results are consistent enough to allow for comparisons from one building to another, as long as the general features of the images (such as margins, line thickness, and resolution), parameters of the box counting algorithm, and statistical processing of the results are carefully controlled.
The first five chapters of the book introduce fractals and the fractal dimension, and explain the methodology used by the authors for this analysis, also applying the same analysis to classical fractal structures including the Apollonian gasket, Fibonacci word, Koch snowflake, Minkowski sausage, pinwheel tiling, terdragon, and Sierpiński triangle. The remaining six chapters explain the authors' choice of buildings to analyze, apply their methodology to 625 drawings from 85 homes, built between 1901 and 2007, and perform a statistical analysis of the results.
The authors use this technique to study three main hypotheses, with a fractal structure of subsidiary hypotheses depending on them. These are
That the decrease in the complexity of social family units over the period of study should have led to a corresponding decrease in the complexity of their homes, as measured by a reduction in the fractal dimension.
That distinctive genres and movements in architecture can be characterized by their fractal dimensions, and
That individual architects can also be characterized by the fractal dimensions of their designs.
The first and third hypotheses are not convincingly supported by the analysis, but the results suggest further work in these directions. The second hypothesis, on distinctive fractal descriptions of genres and movements, does not appear to be true, leading the authors to weaker replacements for it.
Audience and reception
The book is aimed at architects and architecture students; its mathematical content is not deep, and it does not require much mathematical background of its readers. Reviewer Joel Haack suggests that it could also be used for general education courses in mathematics for liberal arts undergraduates.
References
Fractals
Architecture books
Mathematics books
2016 non-fiction books
Birkhäuser books | The Fractal Dimension of Architecture | [
"Mathematics"
] | 552 | [
"Mathematical analysis",
"Functions and mappings",
"Mathematical objects",
"Fractals",
"Mathematical relations"
] |
64,345,638 | https://en.wikipedia.org/wiki/Arithmologia | Arithmologia, sive De Abditis Numerorum Mysteriis is a 1665 work by the Jesuit scholar Athanasius Kircher. It was published by Varese, the main printing house for the Jesuit order in Rome in the mid-17th century. It was dedicated to Franz III. Nádasdy, a convert to Catholicism to whom Kircher had previously co-dedicated Oedipus Aegyptiacus. Arithmologia is the only one of Kircher's works devoted entirely to different aspects of number symbolism.
Content
Arithmologia was concerned with exploring numbers as the underlying principle and structure of the universe, and as the key to mystic understanding previously revealed to patriarchs and philosophers in ancient times. The field of arithmology may be understood as the intersection of traditional religious numerology and contemporary mathematics, drawing on ideas from Pythagoras, Gnosticism, and the Kabbala. The work discussed the significance of numbers in astrology, divination, magic formulas, amulets, seals and symbolic matrices. Kircher's purpose, as he declared in the final chapter, was to articulate a Christian philosophy of number, revealing the hidden harmonies within the material world and its connections with the spiritual.
Illustrations
The frontispiece depicts, at the top, the all-seeing Eye of Providence within a triangle representing the Holy Trinity. In each angle Hebrew letters spell out Jah, the name of God. Around this the nine orders of angels are arranged in three more overlapping triangles. Beneath this fly two putti, one carrying a ruler and a plumb line, while the other carries a tablet with the magic square of three. Within this square, numbers can be added by row, by column or diagonally, but always add up to fifteen.
In the centre of the image is a winged representation of the cosmos; the winged sphere was an ancient Egyptian symbol that Kircher interpreted as meaning the anima mundi. On the outer rim of this sphere are the primum mobile and the fixed stars, and within them the planets orbiting around the static earth at the centre. Beneath this, in the realm of the physical world, sit a learned Jew with an open book displaying the stars of David and Solomon, and a classical philosopher pointing to a model of Pythagoras' theorem.
Further reading
Sincretismo y paracristianismo: Peculiaridades inherentes al ideario filosófico presentes en la Arithmologia de Athanasius Kircher. Álvaro Patricio Jiménez Vargas (PhD thesis)
References
External links
digital copy of Arithmologia
high resolution image of frontispiece
1660s in Italy
1665 in science
Mathematics and mysticism
Arithmetic
Athanasius Kircher | Arithmologia | [
"Mathematics"
] | 574 | [
"Arithmetic",
"Number theory"
] |
64,345,705 | https://en.wikipedia.org/wiki/Sarala%20Sagar%20Project | Sarala Sagar is located in Wanaparthy District, Telangana, India, away from National Highway 44.
History
Sarala Sagar Project is the second biggest dam in Asia with siphon technology. It is the oldest project in India after independence Raja of Wanaparthy Raja Rameshwara Rao founded by the Sarala Sagar Dam Project that has incorporated siphon technology from California, United States. 1949 project was inaugurated by the military former Governor of Hyderabad General J.N Chowdary. The project construction stopped 9 years due to some unknown reasons and was later resumed in 1959. Presently this project provides irrigating a vast area of 4,182 Acres of agricultural land in the Wanaparthy district.
The project
Sarala sagar Dam capacity is 0.5 tmcft. Construction of the dam was started on September 15, 1949. Most of the catchment area upstream of this dam is located in Mahabubnagar. Telangana Government has taken priority to construct Mission Kakatiya Phase-III work Rs 2.30 crore for desilting and repair of guide walls of the sarala sagar.
Gallery
References
Dams in Telangana
Irrigation projects
Irrigation in India
Wanaparthy district | Sarala Sagar Project | [
"Engineering"
] | 244 | [
"Irrigation projects"
] |
64,345,796 | https://en.wikipedia.org/wiki/Conducted%20emissions | Conducted emissions are the effects in power quality that occur via electrical and magnetic coupling, electronic switch of semiconductor devices, which form a part of electromagnetic compatibility issues in electrical engineering. These affect the ability of all interconnected system devices in the electromagnetic environment, by restricting or limiting their intentional generation, propagation and reception of electromagnetic energy.
Conducted emissions consist a part of electromagnetic interference in circuits that mainly create issues in delivered power quality, owing to interference caused by harmonics arising due to linear & non linear loads present in the electric system mainly due to increasing presence of switched mode power supply and other consumer electronics. Due to these aggregated interferences, the delivered electric power quality from the mains electricity system affects the performance of electrical home appliances. These could include a decrease in lumen output of bulbs, flicker and poor heating of induction coil in kettles, and heating elements of other home appliances in every-day use.
Following the effects of conducted emissions, the electric power quality is classified separately in common AC mains and DC mains systems. Since alternating current technology has been well established, the parameters and the effects in power quality in AC are well established. The parameter for measuring AC power quality is called is termed total harmonic distortion (%THD), and it measures the power quality of power supply for different voltage levels. Due to the recent developments in DC technology, the interconnections between DC and AC mains give rise to harmonic issues not previously experienced. Especially, the effects in DC power quality due to conducted emissions are not well understood. Moreover, the interconnections of AC and DC mains has given rise to further electromagnetic interference issues not previously known. Based on the current EMC standards, conducted emissions are measured from 150 kHz and 30 MHz, however there exists a gap in the electric power quality measured up to 2 kHz and the conducted emissions in the low frequency up to 150 kHz. The gap frequency range is termed Supraharmonics.
Further, following the advancements in telecommunications engineering, the presence of electronic devices has gradually increased in the AC mains grid network towards having more semiconductor based switch devices, giving rise to further electromagnetic interference issues due to conducted emissions in the near and far electromagnetic environment. The electric grid progresses towards becoming increasingly nonlinear system and newer issues in power quality are being addressed.
Technically, conducted emissions may be described as noise in the electric current or voltage generated by the electrical appliance or its susceptibility to it. The main difference between signal noise and emissions is that noise exists in a finite energy signal while emission exists in a finite power signal. As noise in measuring circuits gets filtered out using filters, the emission must be filtered at the device under test at either the AC mains or the DC mains, depending on the device application. The emission source can exist from the source to the receptor and through the circuit where there is electron flow. Usually, the electrical appliance must be factory tested with standards for conducted emission, as the list of common EMC test standards denotes. Moreover, different manufacturers hold different versions of these standards as fit best to their appliances and warranty schemes.
Conducted emissions in electric supply system could be described as non-linearity or deviations observed in electric parameters. In AC, the variations are observed in the harmonics, while in DC they are observed as non linearity observed in time-domain and unexpected frequency peaks in frequency domain. The effects of conducted emissions in power quality in AC mains are well established in IEC standards, particularly in IEC Std 519–2014. Further, conducted emissions in DC are from multiple sources including electronic devices, non linear loads and other rotating magnetic field devices. In electronic devices, these are mainly from the interactions in the RLC circuit and the switching frequency. When loads like motors and generators that have DC magnetic fields, the conducted emission are non linear and difficult to predict. Further, the effects of conducted emissions in DC power quality is not well understood and is being researched extensively.
Effects on electric power quality
Electric power quality in AC mains is well developed and established with empirical data gathered over a century. Many parameters exist to determine and calculate the harmonic along with the noise. Concerning DC mains, much of the DC technology research for electric power distribution was abandoned in the 1920s after it was decided that AC alternating systems were to be applied over large distances. However, due to recent developments in photovoltaic system rooftop solutions and lesser electronic conversion stages required between AC & DC, researchers are now considering DC to be used to supply power to household appliances at low voltage and extra-low voltage levels.
Harmonics in AC Mains
For alternating current technology has been well established in the modern world, the parameter for measuring conducted emissions is well understood and is called total harmonic distortion (%THD). It measures power quality of AC mains for different voltage levels as described in common EMC test standards.
By definition, the AC harmonic is a multiple of the electrical quantity (voltage or current) at multiples of the fundamental frequency of the system, produced by the action of non-linear loads such as rectifier, lighting, or saturated magnetic devices. Harmonic frequencies in the power grid are a frequent cause of power quality problems and can result in increased heating in the equipment and conductors, misfiring in variable speed drives, and torque pulsations in motors. Depending on the frequency of the harmonics, the harmonic pollution is categorized in problems of electric power quality (frequency up to harmonic order 40), electromagnetic compatibility (frequency higher than 150 kHz), and low frequency compatibility (frequency between 2/3 kHz and 150 kHz).
Harmonics in DC Mains
Unlike AC, DC has no fundamental frequency or period and hence there cannot be a multiple of the fundamental frequency over which harmonics can be calculated. Further, the frequency range over which DC harmonics are calculated might not be the same as AC harmonics. Much of research covering DC harmonics suggest use of a percentage low frequency sinusoidal disturbance (%LFSD). This quantity measures the deviations that the DC quantity (voltage or current) over a specified measurement window or an analysis window in a frequency range. The percentage of root of squared summations of these deviations gives a total %LFSD value, which is a near equivalent of the %THD value in AC systems. Further, the DC harmonics are being studied in two frequency bandwidth as per the interference observed empirically.
Other issues with power quality in DC mains are to do with frequency range for conducted emissions in the electromagnetic spectrum. In the range of 0–2 kHz, commonly termed as garbage band, the DC harmonic quantity is calculated using an analogue of AC harmonics in frequency domain. However, as per the expected interactions between AC and DC systems and due to presence of power electronic devices and switched-mode power supply, the frequency range 2–150 kHz, recently termed as supraharmonics is being researched. It is primarily understood that due to the presence of electronic switching non-linear loads, the filter circuits tend to push emissions away into higher frequency bands.
Garbage Band
This frequency bandwidth is in the range of 0–2 kHz and is equivalent to the same frequency range as AC harmonics. The name suggest that lower amount of conducted emissions are expected due to advancements in filters. It is widely accepted among researchers that the %LFSD value should be sufficient to address the DC harmonics and relate to the %THD in AC harmonics.
Supraharmonics
This frequency bandwidth is in the range of 2–150 kHz and is termed as supraharmonics. The frequency bandwidth was previously ignored and was considered as a gap between radiated emission and conducted emission. The current research suggest that much effort is being given to understand measurement methods for supraharmonic emissions in order to further standardize DC power quality to include short circuits, voltage variations and other factors as well.
As per Thais.M.Mendes et al., the effects of Supraharmonic emissions are confined to neighboring devices and do not propagate over long distances. Defining the measurement window and analysis window is one of the appropriate way to standardize conducted emissions. Measurements as per IEC 61000-4-7, IEC 61000-4-30, IEC-61000-4-19 and other CISPR standards show that each method can be effective but have its own limitations. Further, as per M.Klattt et al. measurement windows should be used in standardizing the framework for supraharmonic standards. Moreover, V.Khokhlov et al. suggests that all the existing standards have limitations that can be overcome by combining time-based analysis with frequency domain analysis.
References
Electromagnetic compatibility
Electric power quality | Conducted emissions | [
"Engineering"
] | 1,783 | [
"Radio electronics",
"Electrical engineering",
"Electromagnetic compatibility"
] |
64,345,797 | https://en.wikipedia.org/wiki/Black%20box%20model%20of%20power%20converter | The black box model of power converter also called behavior model, is a method of system identification to represent the characteristics of power converter, that is regarded as a black box. There are two types of black box model of power converter - when the model includes the load, it is called terminated model, otherwise un-terminated model. The type of black box model of power converter is chosen based on the goal of modeling. This black box model of power converter could be a tool for filter design of a system integrated with power converters.
To successfully implement a black box model of a power converter, the equivalent circuit of the converter is assumed a-priori, with the assumption that this equivalent circuit remains constant under different operating conditions. The equivalent circuit of the black box model is built by measuring the stimulus/response of the power converter.
Different modeling methods of power converter could be applied in different circumstances. The white box model of power converters is suitable when all the inner components are known, which can be quite difficult due to the complex nature of the power converter. The grey box model combines some features from both, black box model and white box model, when parts of components are known or the relationship between physical elements and equivalent circuit is investigated.
Assumption
Since the power converter consists of power semiconductor device switches, it is a nonlinear and time-variant system. One assumption of black box model of a power converter is that the system is regarded as linear system when the filter is designed properly to avoid saturation and nonlinear effects. Another strong assumption related to the modeling procedure is that the equivalent circuit model is invariant under different operating conditions. Since in the modeling procedures circuit components are determined under different operating conditions.
Equivalent circuit
The expression of a black box model of power converter is the assumed equivalent circuit model (in frequency domain), which could be easily integrated in the circuit of a system in order to facilitate the process of filter design, control system design and pulse-width modulation design. In general, the equivalent circuit contains mainly two parts: active components like voltage/current sources, and passive components like impedance. The process of black box modeling is actually an approach to determine this equivalent circuit for the converter.
Active components
The active components in equivalent circuit are voltage/current sources. They are usually at least two sources, which could be variety options depending on the analysis approach, such as two voltage sources, two current sources, and one voltage and one current source.
Passive components
The passive components containing resistors, capacitors and inductors can be expressed as combination of several impedances or admittances. Another expression method is to regard the passive components of the power converter as a two-port network and use a Y-matrix or Z-matrix to describe the characteristics of passive components.
Modeling method
Different modeling methods can be utilized to define the equivalent circuit. It depends on the chosen equivalent circuit and the optional measurement techniques. However, many modeling methods need at least one or more assumption mentioned above in order to regard the systems as linear time-invariant system or periodically switched linear system.
One example of modeling method
This method is based on the two assumptions mentioned in section Assumption, so the system is regarded as linear time-invariant system. Based on these assumptions, the equivalent circuit could be derived from several equations of different operating conditions. The equivalent circuit model is defined containing three impedances and two current sources, where five unknown parameters needs to be determined. Three sets of different operating conditions are built up by changing external impedance and the corresponding currents and voltages at the terminals of the power converter are measured or simulated as known parameters. In each condition, two equations containing five unknown variables could be derived according to Kirchhoff's circuit laws and nodal analysis. In total, six equations could be used to solve these five unknowns and the equivalent circuit could be determined in this way.
Other methods to determine passive elements
There are many methods used to determine passive elements. The conventional method is to switch off the power converter and measure the impedance with an impedance analyzer, or measure the scattering parameters by a vector network analyzer and compute the impedance afterwards. These conventional methods assume that the impedances of power converter is the same in the operating condition and switched-off condition.
Many state-of-art methods are investigated to measure the impedance when the power converter is in operating condition. One method is to put two clamp-on current probes in the system, in which one is called receiving probe and another is injecting probe. The output of two probes are connected on a vector network analyzer, the impedance of power converter is measured after some calibration procedures in CM and DM measurement setups. This method is restricted with its delicate calibration procedure.
Another state-of-art method is to utilize a transformer and an impedance analyzer in two different setups in order to measure CM and DM impedance separately. The measurement range of this method is limited by the characteristics of the transformer.
See also
black box
grey box model
system identification
nonlinear system identification
linear time-invariant system
time-variant system
nonlinear system
References
Electromagnetic compatibility
Systems theory
Dynamical systems | Black box model of power converter | [
"Physics",
"Mathematics",
"Engineering"
] | 1,069 | [
"Radio electronics",
"Electromagnetic compatibility",
"Mechanics",
"Electrical engineering",
"Dynamical systems"
] |
64,345,803 | https://en.wikipedia.org/wiki/Aerial%20base%20station | An Aerial base station (ABS), also known as unmanned aerial vehicle (UAV)-mounted base station (BS), is a flying antenna system that works as a hub between the backhaul network and the access network.
If more than one ABS is involved in such a relaying mechanism the so-called fly ad-hoc network (FANET) is established. FANETs are an aerial form of wireless ad hoc networks (WANET)s or mobile ad hoc networks (MANET)s.
To provide "connectivity from the sky" is one of the innovative aspects of the 5G network. A strategic difference of ABSs with respect to the static classical network architecture is their ability to deploy on-demand networks at specific locations, thanks to their in-built properties of mobility, flexibility in three-dimensional space, adaptive altitude, and symmetric rotation. These characteristics allow to offer to ground users premium services with high quality wireless links, poor degradation, high capacity and low interference.
From an industry point of view, different use cases have been planned for ABS network deployment in order to provide connectivity during temporary events and emergency situations, and in zones or rural areas without pre-existing solid network infrastructure.
Unmanned aerial vehicles in wireless communications
UAV were born only for military aims. Thanks to the evolution of the manufacturing technology, nowadays, it is one of the candidate solutions to provide on-demand connectivity in 5G network systems.
History
UAVs, more commonly identified as drones, are small aircraft or balloons that can be controlled in a remote manner by a radio control/RF module or using intelligent on-board systems that make the drone autonomous, simply cooperating with the network infrastructure and without human interaction.
Historically, UAVs were only considered as expensive toys, thus, they were mainly used for military purposes such as cargo delivery, remote surveillance, armed attacks, and to reduce the soldiers losses in harsh territory since only a remote human pilot with a radiofrequency control was involved. The primitive use of a UAV was recorded at Venice in 1849 when the Austrians attacked Italy using unmanned balloons furnished with explosives. Applications of UAVs were also present during the first and second world wars.
Thanks to the advancement of on-board sensors and manufacturing technologies, in the second half of the twentieth century, UAVs were also used for espionage and hostage search using wireless sensors.
In the early 2000s, both the costs and the size reduced, thus, UAVs civilian and commercial applications started to be predominant, allowing a myriad of uses in the wireless communications field with the support of the existing network architecture, such as package delivery and traffic control in smart city context, or precision agriculture and terrain inspection in Industry 4.0. It is worth noting that in all these scenarios UAVs work as aerial user equipments (UEs), in coexistence with the classical ground users of the network, and not as an integrated part of the network infrastructure itself. Such a wireless technology is generally referred as cellular-connected UAVs. Amazon Air and Google’s project Wing initiatives are prominent examples of cellular-connected UAVs use cases.
In recent years, due to the continuous miniaturization of components of wireless communication apparatus, the idea of equipping UAVs with radio frequency transceivers and dedicated hardware, to provide reliable, cost-effective, and on-demand wireless links to users on the ground, has started to be a reality. Nowadays, It is possible to find transceivers with a weight less than 2 kilograms, such as universal software radio peripheral integrated with software-defined radio, which can be easily mounted on the aircraft using a 3D printed support.
The new concept of UAV-assisted wireless communications is a promising technology to support the fast-growing wireless data traffic. As a result of industry testing and academic research, ABSs are identified as an important component of 5G and beyond network.
Key and challenging aspects
The integration of ABSs or FANETs into wireless cellular networks as aerial communication platforms brings new network infrastructure design possibilities and challenging aspects to take into account. Indeed, there are many differences compared to the terrestrial counterpart.
high altitude: the typical height of terrestrial BSs is around 10-20 meters in an urban scenario, whereas the current regulation allows the ABSs to hover up to 100-120 meters. This enables the ABS to achieve broader coverage compared to classical terrestrial infrastructure and reduce the interference from other terminals. In fact, the ground terminals can be easily discernible at different altitudes and elevation angles measured with respect to the ABS;
3D high mobility and user tracking: ABS can provide a higher line of sight (LoS) channel probability than classical ground-to-ground communications that generally suffer more path loss attenuation and fading effects. ABSs transceivers can track the moving users (pedestrian, connected vehicles or Internet of things devices) maintaining a stable LoS connection. There are several advantages of such condition. For instance, in 5G networks, millimeter-waves are employed and LoS is vital for providing connectivity at these frequency bandwidths. Moreover, LoS condition enables effective beamforming in the 3D space, making ABSs suitable candidates for the so-called 3D MIMO;
FANETs are scalable networks where the number of involved ABSs can be changed dynamically and based on use-case. Usually information among ABSs in FANETs is exchanged using the 802.11p protocol used for vehicular communications. The term ad-hoc refers to the fact that FANETs are characterized by a decentralized routing protocol for data information transmission;
energy-efficient design: ABSs, and UAVs in general, are really energy limited systems; this aspect poses critical bounds on their hovering and flight time, and some trade off can arise in terms of quality of services provided to user (i.e. transmitted power) and energy constrains;
security and surrounding environment health: the ABSs and their sensors need to be continually monitored to avoid incidents and maintain safety distance with others aerial vehicles, buildings, and obstacles. For this purpose, a control link is established with the terrestrial backhaul network;
privacy and data protection: the information collected by the on-board sensors are an issue in terms of both individuals and businesses privacy.
Impact and applications scenarios
ABSs allow a mobile operator/connectivity provider or network designers to create on demand networks in a bordered area that cater to particular clients and use cases. Lightweight, Commercial BSs are suitable to be mounted on UAVs with a moderate payload allowing a wide range of applications:
effectively accompaniment existing terrestrial systems in crowded areas (e.g., stadium during a sport event or live performances) by providing additional capacity;
information dissemination and collection in wireless sensor networks and IoT scenarios (smart city or in fields for terrain inspection and precision agriculture) where, due to low transmitted power of the devices, long range communications are not possible;
information transmission among geographically separated data centres or delivering network coverage in hard to reach rural or suburban areas, where deploying ABSs becomes highly advantageous compared to expensive telecommunications towers for BS or fiber links installation;
fast connectivity restoration after infrastructure failure or data relaying in emergency situations such as terroristic attacks. An example is the link between the frontline and the headquarters during such unpredictable situations;
Models of such an innovative technology are provided by Qualcomm and AT&T that have experimented the deployment of ABSs for enabling wide-scale wireless communications. Also, projects such as Facebook Aquila, cell-on-wheels and wings (COW-W), Google SKYBENDER, Nokia F-Cell, Huawei Digital Sky are aimed for testing the benefits of ABS services.
Regulations
One of the significant barriers of ABSs wireless communication technology is the absence of unique legal regulation. Policy differs among countries and zones.
The regulations criteria can be split into two categories, the first related to UAV technology and the second related to telecommunications.
Concerning UAVs, there are different agencies that develop guidelines for flight control. In the United States, operations are controlled by the Federal Aviation Administration (FAA) and National Aeronautics and Space Administration (NASA). In Europe, the European Aviation Safety Agency (EASA) has published the regulation on the use of UAV. The International Civil Aviation Organization (ICAO) is concerned with the Asia guideline for the regulation and safe operation of unmanned aircraft systems.
Wireless communication regulations are being continuously developed by different organizations, such as the Electronic Communications Committee (ECC) in Europe and the Federal Communications Commission (FCC) in the United States. The aim is to control the operations of ABS considering various factors such as ABS type and identification, frequency spectrum for data sharing and sensors control, altitude that depends on the presence of line of sight with the pilot, speed and weight.
Architectures overview
Although 3GPP is still concentrating its efforts on cellular-connected UAVs standardization, there are different proposed wireless architectures that involve flying systems carrying an intelligent router. The architecture involving ABSs is generally characterized by two basic types of communication links: the control and non-payload communications (CNPC) link and the data link.
Control and non-payload communications link
Control and non-payload communications link involves communications between the ABSs and ground control centres of the backhaul network that it is generally a specialized BS. CNPC link has mainly safety-critical functions, such as real-time control and obstacle collision avoidance. For this purpose, it needs more stringent latency and security requirements. Security and privacy are also prioritized to avoid unauthorized controllers. The CNPC link is also used for delivering information about the network configuration, which determines time and frequency resource allocation, and to collect some information about the ABSs's flight data (such as GPS, relative elevation angle, and flight speed), residual energy, and performances about the provide connectivity (such as average bit error rate, received and transmitted power). The frequency bandwidths allocated for this link are L-bands and C-bands since they do not suffer severe path loss, allowing a high reliability and low delay communications.
Data link
The data links involve the transmission of information data among mobile ground devices, terrestrial infrastructure (BS or gateway), sensors, and others ABSs. Since its scope is different compared to the CNPC, the requirements also vary. The data link is less delay-sensitive than the CNPC link, while the capacity request is generally application dependent. The data rate can range from kilobits per second in case of ABSs-ground users link, so that the 4G frequency bandwidth can be adopted, up to gigabits per second in case of ABS-backhaul network or ABS-ABS communications. Since these latter are mainly dominated by LoS component, the utilization of millimeter-wave bandwidth is a prominent solution for guaranteeing the high capacity requirement.
Placement considerations
The problem of finding an optimum location and/or path planning is more challenging for ABSs compared to the conventional terrestrial BSs. On one hand ABSs can freely move in 3D space without any borders, on the other hand, there are also variety of applied constraints that need to be considered, e.g., maintain LoS connectivity, energy limitation, and obstacles collision avoidance, many of which are time dependent and are difficult to predict.
In most of the cases, the optimal solution is application-based. For instance, in case of cellular coverage ABSs-supported, the solution is to deploy static ABS that hovers above the centre of the area to be covered. In case of real time applications or moving devices, it is more intuitive to employ more than one ABSs to cooperatively achieve low delay and high reliability communications. Also in case of energy-aware deployment several ABSs need to cooperate letting the ABS to leave the serving area for energy replenishment, meanwhile the connectivity gap is filled by neighbouring ABSs, for example, via increasing the transmission power and/or adjusting the aircraft positions.
See also
5G
UAV
List of unmanned aerial vehicle applications
Regulation of unmanned aerial vehicles
History of unmanned aerial vehicles
MANET
millimeter-wave
access network
Universal Software Radio Peripheral
References
Unmanned aerial vehicles
Wireless
Avionics | Aerial base station | [
"Technology",
"Engineering"
] | 2,460 | [
"Wireless",
"Avionics",
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64,345,806 | https://en.wikipedia.org/wiki/Rashba%E2%80%93Edelstein%20effect | The Rashba–Edelstein effect (REE) is a spintronics-related effect, consisting in the conversion of a bidimensional charge current into a spin accumulation. This effect is an intrinsic charge-to-spin conversion mechanism and it was predicted in 1990 by the scientist V.M. Edelstein. It has been demonstrated in 2013 and confirmed by several experimental evidences in the following years.
Its origin can be ascribed to the presence of spin-polarized surface or interface states. Indeed, a structural inversion symmetry breaking (i.e., a structural inversion asymmetry (SIA)) causes the Rashba effect to occur: this effect breaks the spin degeneracy of the energy bands and it causes the spin polarization being locked to the momentum in each branch of the dispersion relation. If a charge current flows in these spin-polarized surface states, it generates a spin accumulation. In the case of a bidimensional Rashba gas, where this band splitting occurs, this effect is called Rashba–Edelstein effect.
For what concerns a class of peculiar materials, called topological insulators (TI), spin-splitted surface states exist due to the surface topology, independently from the Rashba effect. Topological insulators, indeed, display a spin-splitted linear dispersion relation on their surfaces (i.e., spin-polarized Dirac cones), while having a band gap in the bulk (this is why these materials are called insulators). Also in this case, spin and momentum are locked and, when a charge current flows in these spin-polarized surface states, a spin accumulation is produced and this effect is called Edelstein effect. In both cases, a 2D charge-to-spin conversion mechanism occurs.
The reverse process is called the inverse Rashba–Edelstein effect and it converts a spin accumulation into a bidimensional charge current, resulting in a 2D spin-to-charge conversion.
The Rashba–Edelstein effect and its inverse effect are classified as a spin-charge interconversion (SCI) mechanisms, as the direct and inverse spin Hall effect, and materials displaying these effects are promising candidates for becoming spin injectors, detectors and for other future technological applications.
The Rashba–Edelstein effect is a surface effect, at variance with the spin Hall effect which is a bulk effect. Another difference among the two, is that the Rashba–Edelstein effect is a purely intrinsic mechanism, while the spin Hall effect origin can be either intrinsic or extrinsic.
Physical origin
The origin of the Rashba–Edelstein effect relies on the presence of spin-split surface or interface states, which can arise for a structural inversion asymmetry or because the material exhibits a topologically protected surface, being a topological insulator. In both cases, the material surface displays the spin polarization locked to the momentum, meaning that these two quantities are univocally linked and orthogonal one to the other (this is clearly visible from the Fermi countours). It is worth noticing that also a bulk inversion asymmetry could be present, which would result in the Dresselhaus effect. In fact, if, in addition to the spatial inversion asymmetry or to the topological insulator band structure, also a bulk inversion asymmetry is present, the spin and momentum are still locked but their relative orientation is not straightforwardly determinable (since also the orientation of the charge current with respect to the crystallographic axes plays a relevant role). In the following discussion, the Dresselhaus effect will be neglected, for simplicity.
The topological insulator case is easier to visualize due to the presence of a single Fermi contour, therefore the topological insulator case is discussed first. Topological insulators display spin-split surface states where spin-momentum locking is present. Indeed, when a charge current flows in the surface states of the topological insulator, it can also be seen as a well-defined momentum shift in the reciprocal space, resulting in a different occupation of the spin-polarized branches of the Dirac cone. This unbalance, according to the structure of the topological insulator band dispersion relation, produces a spin accumulation in the investigated material, i.e., a charge-to-spin conversion occurs. The spin accumulation is orthogonal to the injected charge current, accordingly to spin-momentum locking. Due to the fact that these materials display a conductive behaviour on their surface while being insulating on their bulk, the charge current is only allowed to flow on the topological insulator surfaces: this is the origin of the bidimensionality of this charge-to-spin conversion mechanism.
For what concerns the Rashba–Edelstein effect, the spin-split dispersion relation consists in two bands displaced along the k-axis due to a structural inversion asymmetry (SIA), accordingly to the Rashba effect (i.e., these bands show a linear splitting in k due to the spin-orbit coupling). This results in two Fermi countours, which are concentric at equilibrium, both displaying spin-momentum locking but with opposite helicity. If the system is driven in an out-of-equilibrium condition by injecting a charge current, the two disk displace one from the other and a net spin accumulation arises. This effect occurs, for instance, in a bidimensional Rashba gas. The Rashba splitting complicates the understanding and the visualization of the spin-to-charge conversion mechanism but the basic working principle of the Rashba–Edelstein effect is very similar to the one of the Edelstein effect.
Experimentally speaking, the Rashba–Edelstein effect occurs if a charge current is electrically injected inside the topological insulator, for instance by means of two electrodes where a potential difference is applied. The resulting spin accumulation can be probed in several ways, one of them is by employing the magneto optical Kerr effect (MOKE).
Inverse Rashba–Edelstein effect
The reverse process, i.e., the inverse Rashba–Edelstein effect (I(R)EE) occurs when a spin accumulation is generated inside the investigated material and a consequent charge current arises on the material surface (in this case, we have a 2D spin-to-charge conversion). In order to have the inverse Rashba–Edelstein effect, a spin accumulation is required to be generated inside the analyzed material, and this spin injection is usually achieved by coupling the material under investigation with a ferromagnet in order to perform the spin pumping or with a semiconductor where it is possible to perform optical orientation. As for the direct effect, the inverse Rashba–Edelstein effect occurs in materials lacking the structural inversion symmetry, while in topological insulators the inverse Edelstein effect arises.
In the case of the inverse Edelstein effect, by looking at the section of the Dirac cone, the spin-to-charge conversion can be visualized as follows: the spin injection produces a piling up of spins of one character in one of the energy dispersion relation branches. This results in a spin unbalance due to the different branch occupations (i.e., a spin accumulation), which leads to a momentum unbalance and, therefore, to a charge current which can be electrically probed. As for the direct effect, also in the inverse Edelstein effect, the charge current can only flow on the topological insulator surfaces due to the energy band conformation. This is how the 2D spin-to-charge conversion occurs in these materials and this could allow topological insulators to be exploited as spin detectors.
As for the direct effect, this analysis has been carried out for the inverse Edelstein effect because in this case only two energy branches are present. For what concerns the inverse Rashba–Edelstein effect, the process is very similar despite the presence of four energy branches, with spin-momentum locking, in the dispersion relation and two consequent Fermi countours with opposite helicity. In this case, the two Fermi countours, when a spin accumulation is generated inside the material, will be displaced one from the other, generating a charge current, at variance with the equilibrium case in which the two Fermi countours are concentric and no net momentum unbalance nor spin accumulation are present.
Process efficiency
While both the Rashba–Edelstein effect and the inverse Rashba–Edelstein effect rely on a spin accumulation, the figure of merit of the processes is commonly computed by accounting for the spin current density related to the spin accumulation, instead of the spin accumulation itself, in analogy with the spin Hall angle for the spin Hall effect. Indeed, the efficiency of the Rashba–Edelstein effect and of the inverse Rashba–Edelstein effect can be estimated by means of the Rashba–Edelstein length, i.e., the ratio between the charge current density, flowing on the surface of the investigated material, (i.e., a surface charge current density) and the three-dimensional spin current density (since the spin accumulation can diffuse in the three-dimensional space).
In the Rashba–Edelstein effect the spin current is a consequence of the spin accumulation that occurs in the material as the charge current flows on its surface (under the influence of a potential difference and, therefore, of an electric field), while in the inverse Rashba–Edelstein effect the spin current is the quantity injected inside the material leading to a spin accumulation and resulting in a charge flow localized at the material surface. In both cases, the asymmetry in the charge and spin current dimensions results in a ratio which dimensionally has the units of a length: this is the origin of the name of this efficiency parameter.
Analytically, the value of the bidimensional charge current density can be computed employing the Boltzmann equation and considering the action of an electric field , resulting in:
,
where is the elementary charge, is the momentum scattering time, and are, respectively, the Fermi wavevector and the Fermi velocity and is the reduced Planck constant.
The spin current density can be also analytically computed by integrating across the Fermi surface the product of the spin polarization and the corresponding distribution function.
In the Edelstein effect case, this quantity results in:
,
where is the unit vector perpendicular to the surface on which the charge current flows.
From these formula it can be observed the orthogonality of the spin and the charge current densities.
For what regards the Edelstein and its inverse effects, the conversion efficiency is:
.
This parameter is conventionally positive for a Fermi contour with a counterclockwise helicity. The Rashba–Edelstein length derivation is the same as the Edelstein one, except for which is substituted by the Rashba parameter , i.e., , resulting in:
.
The Rashba–Edelstein length of the investigated material can be compared to other spin-charge interconversion efficiencies, as the spin-Hall angle, to establish if this material is an efficient spin-charge interconverter, and, therefore, if it could be suitable for spintronic applications. The Rashba–Edelstein length (2D spin-charge interconversion efficiency) can be effectively compared to the spin Hall angle (3D spin-charge interconversion efficiency), by dividing the parameter for the thickness of the spin-splitted surface states in which this 2D conversion occurs. This "equivalent" spin Hall angle for the Rashba–Edelstein effect often results in being close to the unity or even greater than the unity: the Rashba–Edelstein effect, on average, is a more efficient spin-charge interconversion mechanism than the spin Hall effect and this could lead to a future employment of materials displaying this effect in the technological industry.
See also
Spin Hall effect
Topological insulator
Rashba effect
Dresselhaus effect
Spintronics
References
Condensed matter physics
Spintronics
Semiconductors
Quantum magnetism | Rashba–Edelstein effect | [
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64,345,820 | https://en.wikipedia.org/wiki/Anderson%20acceleration | In mathematics, Anderson acceleration, also called Anderson mixing, is a method for the acceleration of the convergence rate of fixed-point iterations. Introduced by Donald G. Anderson, this technique can be used to find the solution to fixed point equations often arising in the field of computational science.
Definition
Given a function , consider the problem of finding a fixed point of , which is a solution to the equation . A classical approach to the problem is to employ a fixed-point iteration scheme; that is, given an initial guess for the solution, to compute the sequence until some convergence criterion is met. However, the convergence of such a scheme is not guaranteed in general; moreover, the rate of convergence is usually linear, which can become too slow if the evaluation of the function is computationally expensive. Anderson acceleration is a method to accelerate the convergence of the fixed-point sequence.
Define the residual , and denote and (where corresponds to the sequence of iterates from the previous paragraph). Given an initial guess and an integer parameter , the method can be formulated as follows:
where the matrix–vector multiplication , and is the th element of . Conventional stopping criteria can be used to end the iterations of the method. For example, iterations can be stopped when falls under a prescribed tolerance, or when the residual falls under a prescribed tolerance.
With respect to the standard fixed-point iteration, the method has been found to converge faster and be more robust, and in some cases avoid the divergence of the fixed-point sequence.
Derivation
For the solution , we know that , which is equivalent to saying that . We can therefore rephrase the problem as an optimization problem where we want to minimize .
Instead of going directly from to by choosing as in fixed-point iteration, let's consider an intermediate point that we choose to be the linear combination , where the coefficient vector , and is the matrix containing the last points, and choose such that it minimizes . Since the elements in sum to one, we can make the first order approximation , and our problem becomes to find the that minimizes . After having found , we could in principle calculate .
However, since is designed to bring a point closer to , is probably closer to than what is, so it makes sense to choose rather than . Furthermore, since the elements in sum to one, we can make the first order approximation . We therefore choose
.
Solution of the minimization problem
At each iteration of the algorithm, the constrained optimization problem , subject to needs to be solved. The problem can be recast in several equivalent formulations, yielding different solution methods which may result in a more convenient implementation:
defining the matrices and , solve , and set ;
solve , then set .
For both choices, the optimization problem is in the form of an unconstrained linear least-squares problem, which can be solved by standard methods including QR decomposition and singular value decomposition, possibly including regularization techniques to deal with rank deficiencies and conditioning issues in the optimization problem. Solving the least-squares problem by solving the normal equations is generally not advisable due to potential numerical instabilities and generally high computational cost.
Stagnation in the method (i.e. subsequent iterations with the same value, ) causes the method to break down, due to the singularity of the least-squares problem. Similarly, near-stagnation () results in bad conditioning of the least squares problem. Moreover, the choice of the parameter might be relevant in determining the conditioning of the least-squares problem, as discussed below.
Relaxation
The algorithm can be modified introducing a variable relaxation parameter (or mixing parameter) . At each step, compute the new iterate as The choice of is crucial to the convergence properties of the method; in principle, might vary at each iteration, although it is often chosen to be constant.
Choice of
The parameter determines how much information from previous iterations is used to compute the new iteration . On the one hand, if is chosen to be too small, too little information is used and convergence may be undesirably slow. On the other hand, if is too large, information from old iterations may be retained for too many subsequent iterations, so that again convergence may be slow. Moreover, the choice of affects the size of the optimization problem. A too large value of may worsen the conditioning of the least squares problem and the cost of its solution. In general, the particular problem to be solved determines the best choice of the parameter.
Choice of
With respect to the algorithm described above, the choice of at each iteration can be modified. One possibility is to choose for each iteration (sometimes referred to as Anderson acceleration without truncation). This way, every new iteration is computed using all the previously computed iterations. A more sophisticated technique is based on choosing so as to maintain a small enough conditioning for the least-squares problem.
Relations to other classes of methods
Newton's method can be applied to the solution of to compute a fixed point of with quadratic convergence. However, such method requires the evaluation of the exact derivative of , which can be very costly. Approximating the derivative by means of finite differences is a possible alternative, but it requires multiple evaluations of at each iteration, which again can become very costly. Anderson acceleration requires only one evaluation of the function per iteration, and no evaluation of its derivative. On the other hand, the convergence of an Anderson-accelerated fixed point sequence is still linear in general.
Several authors have pointed out similarities between the Anderson acceleration scheme and other methods for the solution of non-linear equations. In particular:
Eyert and Fang and Saad interpreted the algorithm within the class of quasi-Newton and multisecant methods, that generalize the well known secant method, for the solution of the non-linear equation ; they also showed how the scheme can be seen as a method in the Broyden class;
Walker and Ni showed that the Anderson acceleration scheme is equivalent to the GMRES method in the case of linear problems (i.e. the problem of finding a solution to for some square matrix ), and can thus be seen as a generalization of GMRES to the non-linear case; a similar result was found by Washio and Oosterlee.
Moreover, several equivalent or nearly equivalent methods have been independently developed by other authors, although most often in the context of some specific application of interest rather than as a general method for fixed point equations.
Example MATLAB implementation
The following is an example implementation in MATLAB language of the Anderson acceleration scheme for finding the fixed-point of the function . Notice that:
the optimization problem was solved in the form using QR decomposition;
the computation of the QR decomposition is sub-optimal: indeed, at each iteration a single column is added to the matrix , and possibly a single column is removed; this fact can be exploited to efficiently update the QR decomposition with less computational effort;
the algorithm can be made more memory-efficient by storing only the latest few iterations and residuals, if the whole vector of iterations is not needed;
the code is straightforwardly generalized to the case of a vector-valued .
f = @(x) sin(x) + atan(x); % Function whose fixed point is to be computed.
x0 = 1; % Initial guess.
k_max = 100; % Maximum number of iterations.
tol_res = 1e-6; % Tolerance on the residual.
m = 3; % Parameter m.
x = [x0, f(x0)]; % Vector of iterates x.
g = f(x) - x; % Vector of residuals.
G_k = g(2) - g(1); % Matrix of increments in residuals.
X_k = x(2) - x(1); % Matrix of increments in x.
k = 2;
while k < k_max && abs(g(k)) > tol_res
m_k = min(k, m);
% Solve the optimization problem by QR decomposition.
[Q, R] = qr(G_k);
gamma_k = R \ (Q' * g(k));
% Compute new iterate and new residual.
x(k + 1) = x(k) + g(k) - (X_k + G_k) * gamma_k;
g(k + 1) = f(x(k + 1)) - x(k + 1);
% Update increment matrices with new elements.
X_k = [X_k, x(k + 1) - x(k)];
G_k = [G_k, g(k + 1) - g(k)];
n = size(X_k, 2);
if n > m_k
X_k = X_k(:, n - m_k + 1:end);
G_k = G_k(:, n - m_k + 1:end);
end
k = k + 1;
end
% Prints result: Computed fixed point 2.013444 after 9 iterations
fprintf("Computed fixed point %f after %d iterations\n", x(end), k);
See also
Fixed-point
Fixed-point iteration
Root-finding algorithms
Notes
References
Numerical analysis
Quasi-Newton methods
Iterative methods | Anderson acceleration | [
"Mathematics"
] | 1,937 | [
"Computational mathematics",
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64,345,824 | https://en.wikipedia.org/wiki/Elastix%20%28image%20registration%29 | Elastix is an image registration toolbox built upon the Insight Segmentation and Registration Toolkit (ITK). It is entirely open-source and provides a wide range of algorithms employed in image registration problems. Its components are designed to be modular to ease a fast and reliable creation of various registration pipelines tailored for case-specific applications. It was first developed by Stefan Klein and Marius Staring under the supervision of Josien P.W. Pluim at Image Sciences Institute (ISI). Its first version was command-line based, allowing the final user to employ scripts to automatically process big data-sets and deploy multiple registration pipelines with few lines of code. Nowadays, to further widen its audience, a version called SimpleElastix is also available, developed by Kasper Marstal, which allows the integration of elastix with high level languages, such as Python, Java, and R.
Image registration fundamentals
Image registration is a well-known technique in digital image processing that searches for the geometric transformation that, applied to a moving image, obtains a one-to-one map with a target image. Generally, the images acquired from different sensors (multimodal), time instants (multitemporal), and points of view (multiview) should be correctly aligned to proceed with further processing and feature extraction. Even though there are a plethora of different approaches to image registration, the majority is composed of the same macro building blocks, namely the transformation, the interpolator, the metric, and the optimizer. Registering two or more images can be framed as an optimization problem that requires multiple iterations to converge to the best solution. Starting from an initial transformation computed from the image moments the optimization process searches for the best transformation parameters based on the value of the selected similarity metric. The figure on the right shows the high-level representation of the registration of two images, where the reference remains constant during the entire process, while the moving one will be transformed according to the transformation parameters. In other words, the registration ends when the similarity metric, which is a mathematical function with a certain number of parameters to be optimized, reaches the optimal value which is highly dependent on the specific application.
Main building blocks
Following the structure of the image registration workflow, the elastix toolbox proposes a modular solution that implements for each of the building blocks different algorithms, highly employed in medical image registration, and helps the final users to build their specific pipeline by selecting the most suitable algorithm for each of the main building blocks. Each block is easily configurable both by selecting pre-defined initialization values or by trying multiple sets of parameters and then choosing the most performing one. The registration is performed on images, and the elastix toolbox supports all the data formats supported by ITK, ranging from JPEG and PNG to medical standard formats such as DICOM and NIFTI. It also stores physical pixel spacing, the origin and the relative position to an external world reference system, when provided in the metadata, to facilitate the registration process, especially in medical field applications.
Transformation
The transformation is an essential building block, since it defines the allowable transformations. In image registration, the main distinction can be done between parallel-to-parallel and parallel-to-non parallel (deformable) line mapping transformations. In the elastix toolbox, the final users can select one transformation or compose more transformations either through addition or via composition. Below are reported the different transformation models in order of increasing flexibility, along with the corresponding elastix class names between brackets.
Translation (TranslationTransform) allows only translations
Rigid (EulerTransform) expands the translation adding rotations and the object is seen as a rigid body
Similarity (SimilarityTransform) expands the rigid transformation by introducing isotropic scaling
Affine (AffineTransform) expands the rigid transformation allowing both scaling and shear
B-splines (BSplineTransform) is a deformable transformation usually preceded by a rigid or affine one
Thin-plate splines (SplineKernelTransform) is a deformable transformation belonging to the class of kernel-based transformations that is a composition of and affine and a non-rigid part
Metric
The similarity metric is the mathematical function whose parameters should be optimized to reach the desired registration, and, during the process, it is computed multiple times. Below are reported the available metrics computed employing the reference and the transformed images and the corresponding elastix class names between brackets.
Mean squared difference (AdvancedMeanSquares) to be used for mono-modal applications
Normalized correlation coefficient (AdvancedNormalizedCorrelation) to be used for images that have an intensity linear relationship
Mutual information (AdvancedMattesMutualInformation) to be used for both mono- and multi-modal applications and optimized to reach better performance compared to the normalized version
Normalized mutual information (NormalizedMutualInformation) for both mono- and multi-modal applications
Kappa statistic (AdvancedKappaStatistic) to be used only for binary images
Sampler
For the computation of the similarity metrics, it is not always necessary to consider all the voxels and, sometimes, it can be useful to use only a fraction of the voxels of the images, i.e. to reduce the execution time for big input images. Below are reported the available criteria for selecting a fraction of the voxels for the similarity metric computation and the corresponding elastix class names between brackets.
Full (Full) to employ all the voxels
Grid (Grid) to employ a regular grid defined by the user to downsample the image
Random (Random) to randomly select a percentage of voxels defined by the users (all voxels have equal probability to be selected)
Random coordinate (RandomCoordinate) like the random criterion, but in this case also off-grid positions can be selected to simplify the optimization process
Interpolator
After the application of the transformation, it may occur that the voxels used for the similarity metric computation are at non-voxel positions, so intensity interpolation should be performed to ensure the correctness of the computed values. Below are reported the implemented interpolators and the corresponding elastix class names between brackets.
Nearest neighbor (NearestNeighborInterpolator) exploits little resources, but gives low quality results
Linear (LinearInterpolator) is sufficient in general applications
N-th order B-spline (BSplineInterpolator) can be used to increase the order N, increasing quality and computation time. N=0 and N=1 indicate the nearest neighbor and linear cases respectively.
Optimizer
The optimizer defines the strategy employed for searching the best transformation parameter to reach the correct registration, and it is commonly an iterative strategy. Below are reported some of the implemented optimization strategies.
Gradient descent
Robbins-Monro, similar to the gradient descent, but employing an approximation of the cost function derivatives
A wider range of optimizers is also available, such as Quasi-Newton or evolutionary strategies.
Other features
The elastix software also offers other features that can be employed to speed up the registration procedure and to provide more advanced algorithms to the end-users. Some examples are the introduction of blur and Gaussian pyramid to reduce data complexity, and multi-image and multi-metric framework to deal with more complex applications.
Applications
Elastix has applications mainly in the medical field, where image registration is fundamental to get comprehensive information regarding the analysed anatomical region. It is widely employed in image-guided surgery, tumour monitoring, and treatment assessment.
For example, in radiotherapy planning, image registration allows to correctly deliver the treatment and evaluate the obtained results. Thanks to the wide range of implemented algorithms, the use of the elastix software allows physicians and researchers to test different registration pipelines from the simplest to more complex ones, and to save the best one as a configuration file. This file and the fact that the software is completely open-source makes it easy to reproduce the work, that can help supporting the open science paradigm, and allows fast reuse on different patients data.
In image-guided surgery, registration time and accuracy are critical points, considering that, during the registration, the patient is on the operating table, and the images to be registered have lower resolution compared to the target ones. In this field, the possibility to exploit elastix with high-level languages, such as OpenCL, opens to research in the usage of GPUs and other hardware accelerators.
References
External links
GitHub repository
Computer vision
Medical imaging
Free science software
Software using the Apache license | Elastix (image registration) | [
"Engineering"
] | 1,784 | [
"Artificial intelligence engineering",
"Packaging machinery",
"Computer vision"
] |
64,345,861 | https://en.wikipedia.org/wiki/Advanced%20reprocessing%20of%20spent%20nuclear%20fuel | The advanced reprocessing of spent nuclear fuel is a potential key to achieve a sustainable nuclear fuel cycle and to tackle the heavy burden of nuclear waste management. In particular, the development of such advanced reprocessing systems may save natural resources, reduce waste inventory and enhance the public acceptance of nuclear energy. This strategy relies on the recycling of major actinides (Uranium and Plutonium, and also Thorium in the breeder fuel cycle) and the transmutation of minor actinides (Neptunium, Americium and Curium) in appropriate reactors. In order to fulfill this objective, selective extracting agents need to be designed and developed by investigating their complexation mechanism.
Managing spent nuclear fuel
The estimated inventory of spent nuclear fuel discharged from nuclear power reactors worldwide up to the end of 2013 is about 370,000 . To date, about 250,000 of this inventory is being stored. At the back-end step of the nuclear fuel cycle, two spent fuel management options could be potentially adopted:
Open fuel cycle: the cycle starts with the mining of uranium, goes through the fuel fabrication and ends with the direct disposal of the spent fuel.
Closed fuel cycle: the spent fuel stored for a long time can be safely handled and it undergoes reprocessing in order to recover and recycle a large amount of it.
According to the first option, the spent nuclear fuel is considered complete waste. After an interim storage (wet and dry), all the used fuel is directly disposed of in a deep geological repository. Several geological media and repository designs are being studied according to different natures of fuel and their burnup, radioactive inventory and decay heat generation. The assessment of a geological disposal is based on the multi-barrier approach, which combines multiple effects of engineered and natural barriers in order to delay potential long-lived radionuclide migrations to the biosphere over time.
Reprocessing is the alternative option for the spent fuel after a long interim storage. The used fuel is not considered waste anymore but a future energy resource. A large amount of fertile uranium ( ^{238}U ) is discharged along with a small quantity of fissile ( ^{235}U ) and a non-negligible portion of high level waste products and transuranic elements, which strongly contribute to the long-term radiotoxicity of the spent nuclear fuel. The recovery and recycling of uranium and plutonium were the first steps in developing a closed fuel cycle. Furthermore, a strong reduction of the volume, radiotoxicity and heat load of the spent nuclear fuel can be efficiently achieved.
Despite the benefits of this first reprocessing approach, an amount of waste must be treated, stored and disposed of in a deep geological repository over a long period of time. Waste from reprocessing and spent nuclear fuel are classified as High Level Waste (HLW) according to the IAEA guidance due to the high emission of radioactivity and decay heat.
The first reprocessing approach is based on the PUREX (Plutonium Uranium Reduction EXtraction) process, which is the standard and mature technology applied worldwide to recover uranium and plutonium from spent nuclear fuel at industrial scale. Following the dissolution of the spent fuel in nitric acid and the removal of uranium and plutonium, the generated secondary waste still contains fission and activation products along with transuranic elements that must be isolated from biosphere. Uranium and plutonium are recovered by the well-known tributylphosphate (TBP) ligand in a liquid-liquid extraction process.
Reprocessing allows the recycling of the uranium and plutonium into fresh fuel (RepU and MOX) and a strong reduction of volume, decay heat and radiotoxicity of the HLW. A measure of the HLW hazard is provided by radiotoxicity coming from the different nature of radionuclides. The SNF radiotoxicity is usually evaluated as a function of time and compared to the natural uranium ore. The spent nuclear fuel without reprocessing has a long-term toxicity that is mainly dominated by transuranic elements. Mainly due to plutonium, SNF without reprocessing reaches the reference radiotoxicity level after about 300,000 years. After uranium and plutonium removal, HLW is less radioactive and it decays to the reference level within 10,000 years. Since minor actinides (MAs) also contribute to the long-term decay heat and radiotoxicity of the spent fuel, an advanced reprocessing could further reduce the radiotoxic inventory with a decay to the reference level of about 300 years.
Partitioning & Transmutation strategy
Many efforts are being devoted to develop an advanced reprocessing approach with the aim to further reduce the radiotoxicity inventory of the spent nuclear fuel by removing all minor actinides (Neptunium, Americium and Curium) and the long-lived fission products (LLFP) from the high active raffinate downstream of the PUREX process. Before the conditioning process, the long-lived radionuclides undergo a transmutation into short-lived or stable nuclides by nuclear reactions. This coupled approach is known as Partitioning and Transmutation strategy (P&T), which inclusion in an advanced closed fuel cycle could lead to strongly reduce long-term radiotoxicity, volume and decay heat of the final waste thus simplifying a performance assessment of a future nuclear waste repository and enhancing proliferation resistance criteria.
Two potential process options for the partitioning of spent nuclear fuel are being developed: hydrometallurgical and pyrometallurgical processes. The hydrometallurgical partitioning, also known as solvent extraction process, was born and developed in Europe thereby becoming the reference technology for future SNF reprocessing at industrial level, whereas the pyrometallurgical option started in the United States and Russia as an alternative to the aqueous processes. Unlike plutonium, americium and curium show a very low affinity towards TBP ligand, thus needing further advanced separation processes and different extracting agents such as nitrogen-bearing ligands, also known as soft donors, which have been showing a very good affinity towards actinides. An efficient and selective separation of actinides from lanthanides (Ln) is crucial to meet the Closed Fuel Cycle goal. Lanthanide ions, present in a large mass ratio with respect to actinides in the PUREX raffinate, have a high neutron-capture cross section that would not lead to an efficient minor actinide transmutation. The presence of uranium isotopes and other impurities in the transmutation target could generate further radiotoxic transuranic isotopes by neutron capture, instead of more stable nuclides. Most of the radiotoxic nuclides could be transmuted by thermal neutrons in conventional reactors, but the process would take a lot of time due to the low transmutation efficiency. Recent research is focusing on innovative nuclear transmuters such as Gen IV fast reactors and hybrid reactors (Accelerator-driven Systems). The final product left by the P&T process will be a dense vitrified waste to be disposed of for a smaller period of time. All the benefits coming from the management of nuclear waste by this advanced approach will be a small step towards a sustainable energy source and an increased public acceptance of the nuclear energy.
Overview of European experience in nuclear partitioning
A lot of research funded by the European Commission is being devoted to hydrometallurgical processes for the partitioning and transmutation of trivalent actinides (An). These research programs have first led to multicycle processes, secondly to the development of simplified and innovative processes. The hydrometallurgical partitioning consists of two relevant steps: extraction and stripping. In the first step the organic phase, containing the extracting ligand dissolved in a suitable solvent, is contacted with the aqueous phase coming from the dissolution of the irradiated fuel. The solutes present in the aqueous phase are extracted by a complexation reaction with the extracting agent and transferred into the organic phase in which the formed complexes are soluble. The second step, known as stripping, is obtained by reversing the complexation reaction, where the solutes are back-extracted into another aqueous solution usually different in acidity compared to the previous one. The main goal is to develop reliable and affordable industrial separation processes by lipophilic and hydrophilic ligands to selectively extract minor actinides from the (3–4) M acidic target waste downstream of the PUREX process, but with the more challenging goal to minimize the amount of solid secondary waste. The CHON principle was born to meet this further process requirement, according to which all extractants and molecular reagents used in the developed processes have only to contain atoms of carbon (C), hydrogen (H), oxygen (O) and nitrogen (N), thus incinerable waste to easily release into the environment.
The industrial separation processes will be implemented stepwise by annular centrifugal contactors, developed for the first time at Argonne National Laboratory in the 1970s. The countercurrent process consists of the aqueous and organic phases moving continuously in opposite directions stage by stage. The two immiscible liquids enter each contactor unit, first contacted in the annular region between the housing and the spinning rotor and then centrifuged in the inner part of the unit. Two main ways are currently followed within the partitioning strategy: the heterogeneous and homogeneous recycling. All the first European research projects on hydrometallurgical partitioning started within the heterogeneous recycling, since none of the developed extracting agents were able to selectively extract actinides directly downstream of the PUREX process. This led research to develop first multi-stage and multi-cycle processes. A two-cycle process (DIAMide EXtraction + Selective ActiNide EXtraction) was developed for a selective actinide extraction downstream of a first co-extraction (DIAMEX) of actinides and lanthanides. The recent joint research projects point to develop innovative processes with a reduced number of cycles to directly extract minor actinides (americium and curium) from the PUREX raffinate in one cycle, either by a lipophilic extractant (1cycle-SANEX) or by a hydrophilic ligand (innovative-SANEX). Recent research efforts are being devoted to the homogeneous recycling by Grouped Actinides Extraction (GANEX), which consists in a previous uranium recovery (GANEX 1) and a successive group separation of plutonium, neptunium, americium and curium actinide ions (GANEX 2).
Industrial requirements for an extracting agent
The European experience in nuclear partitioning led to advanced hydrometallurgical separation processes. However, the feasibility of these advanced partitioning processes at industrial level relies on the use of reliable and affordable extracting agents, which have to meet these relevant industrial requirements:
Affinity towards An(III) over Ln(III)
Good An(III) back-extraction to enable solvent recycling
Good solubility in a proper diluent
CHON compliance to reduce secondary waste
Fast complexation kinetics
Hydrodynamic stability to prevent third phase and precipitates formation during extraction process
Chemical and radiolytic stability to prevent solvent degradation
Research on advanced reprocessing of spent nuclear fuel moves on by developing process optimization studies and designing new potential lipophilic and hydrophilic extracting agents that fulfill these industrial requirements.
Actinide partitioning: complexation mechanism
The selective separation of actinides from the PUREX raffinate by advanced processes needs new extracting agents, which must possess a more pronounced affinity towards actinides over lanthanides and other products mostly present in the acidic fuel dissolution. The design and the synthesis of efficient extracting agents rely on a deep knowledge of the complexation mechanism involved in the extraction process. Moreover, the structure and the stability of the ligand complexes with An(III) and Ln(III) upon extraction process, and the ligand selectivity need to be investigated. Research is being devoted to design more N-donor extracting agents, which show promising selectivity towards actinides.
Solvent extraction and complexation chemistry
The liquid-liquid extraction for the selective actinide partitioning (SANEX-like processes) consists of an organic phase, containing an extracting agent dissolved in a suitable solvent mixture, and an aqueous phase, containing the irradiated fuel dissolution in hot nitric acid. The two phases are vigorously mixed to promote the extraction kinetics. The centrifugation process is performed to favour the phase separation and the transfer of the formed complexes from the depleted aqueous phase (raffinate) into the organic phase (extract) where they result more soluble. This solvent separation can be performed by neutral extracting agents dissolved in the solvent. As can be seen in the equation, the solvating ligand (L) extracts the interested metal cation (M) together with its anion (A). The products of this reaction represent all the potential complexes that can form during an extraction process such as with .
The efficiency and the selectivity of the extraction and separation processes can be evaluated by the Distribution coefficients () and the Separation Factors (), as shown by the equations. The distribution coefficient is calculated as the ratio between the concentration of the metal cations in the organic and aqueous phase, whereas the separation factor is calculated as the ratio between the two distribution coefficients.
To perform a selective separation, the distribution ratio of the solute to be extracted must be greater than one, whereas that belonging to the solutes which remain in the aqueous feed must be lower than one. This always yields a separation factor SF > 1. Generally, the effects of acidity and temperature on distribution ratios and the separation factor are investigated because the main species with actinides and lanthanides could be prone to decomplexation upon increasing acidity due to protonation of the ligand or due to increasing temperature. The thermodynamic effects are usually investigated by performing extraction tests at increasing temperature. Furthermore, thermodynamics studies can assess the several alkyl chains of a ligand on its complexation properties towards minor actinides than lanthanides. The extraction processes are based on the complexation of metal ions with lipophilic or hydrophilic ligands. The extracting agent forms a coordination complex with the metal ion as a product of a Lewis acid-base reaction. Ligands are named bases (donors) and contain at least one electron lone pair to donate to metal ions named acids (acceptors). Metal cations in the aqueous feed raffinate are generally solvated by coordinating water molecules through the donor oxygen atoms to form aquo ions [M(H2O)_{n}]^{3+} . The complexation of a metal ion implies therefore the replacement of the coordinated water molecules with the respective ligands. The speed of this substitution plays a crucial role in the complexation kinetics and the following extraction processes. The replacement can be slow for an inert complex or rapid for a labile complex. The ligand could replace all the coordinated water molecules to form an inner sphere complex or just some of them for an outer-sphere complex. The complexation reaction is theoretically based on the Pearson's theory of hard and soft acids and bases, according to which hard acids form strong complexes with hard bases and likewise soft acids form strong complexes with soft bases. In aqueous solutions, hard-hard interactions are electrostatic, while soft-soft interactions usually show a covalent character.
The formation of strong complexes always implies either a large gain of entropy or a large decrease of enthalpy thereby obtaining a large negative value of the complexation free energy. According to Pearson's theory, lanthanide and actinide ions are considered hard acids, thus they bind especially with ligands bearing hard donors such as oxygen atoms by electrostatic interactions. The charge of actinide and lanthanide ions in solution is substantially +3 and the difference in size of these cations is very small. Thus, an efficient separation of minor actinides from lanthanides is very challenging. Actinides seem to be a little less hard than lanthanides, probably due to a longer spatial extent of 5f atomic orbitals with respect to 4f ones, then a selective separation is possible thanks to ligands bearing soft donors such as nitrogen and sulfur atoms, by a different bonding nature compared to hard donors. Despite the potential separation of actinides, a direct extraction from the PUREX raffinate is very hard, due to the presence of many other interfering species in the feed such as activation and fission products. In this perspective, advanced separation processes involving very selective extracting agents are required to achieve an efficient partitioning for the following transmutation process. To sum up, knowledge of hydration, acid-base interactions, kinetics and thermodynamic stabilities and speciation of actinide and lanthanide ions with ligands is of great value to understand a solvent extraction process and to design new and promising extracting agents.
Insight into complexation by spectroscopic techniques
The main objective is to elucidate the complexation and extraction mechanisms of a ligand in order to develop a reliable and affordable extraction process at industrial scale. In this perspective, the formation and the stability of different metal-ligand complexes are first investigated by different spectroscopic techniques on a laboratory scale. Preliminary studies can be performed by Electrospray ionization mass spectrometry (ESI-MS) to qualitatively explore the ligand complexes with lanthanides or actinides. Moreover, quantitative information about speciation and complexation of the ligand with some metal ions representatives of actinides and lanthanides can be obtained by Time-resolved fluorescence spectroscopy (TRLFS) experiments.
Electrospray ionization mass spectrometry
Electrospray ionization mass spectrometry is a very versatile technique, consisting in a transfer of the formed complexes from the injected solution to the gas phase by a soft ionization process without strongly perturbing the complex stability. In addition, a small amount of the prepared solution needs to be injected to obtain the speciation spectra. Speciation of several metal ions can be investigated in monophasic solutions at increasing ligand concentration in order to explore all potential complexes. Collision Induced Dissociation (CID) analysis can be also performed to assess the kinetic stability of the formed complexes by discovering the main fragmentation pathway of the ligand. Besides, the protonation effect on the complexation mechanism can be observed by performing analysis on monophasic solutions at increasing nitric acid concentration. Corroboration of the major complexes involved into the extraction process is generally found by performing experiments on biphasic solutions upon extraction tests. Despite versatility of this spectroscopic technique that directly provides information by changing the ligand to metal ratios, its qualitative nature due to instrumental set-up and potential changes in solution chemistry could partially affect species distribution and its ion abundance. For these reasons, corroboration for the speciation results needs to be found by other spectroscopic techniques.
Time Resolved Laser Fluorescence spectroscopy
Time-resolved laser fluorescence spectroscopy is a sensitive spectroscopic method able to investigate the formation of different complex species in sub-micro molar concentrations. Thanks to the great spectroscopic properties of some metal cations representatives of actinides and lanthanides, fluorescence analyses by laser excitation of ion energy levels can be carried out on monophasic and biphasic solutions. The fluorescence evolution resulting from the ion energy transitions is generally followed as a function of ligand concentration in monophasic titration experiments. The bathochromic shift of the fluorescence spectra are due to the ligand complexation. According to the postulated complexation model and the Slope Analysis on the experimental data, the stoichiometry of the major complexes can be determined. Moreover, the cumulative stability constants and the Separation Factor can be calculated, thus pointing out the potential ligand affinity towards actinides.
The fluorescence lifetime measurement is an additional way to follow the evolution of the metal-ion complexation with the ligand, starting from the initial solvent species up to the more stable complexes. Each species can be identified by a typical lifetime related to the decay of the emission intensity. The fluorescence lifetime measurements on the monophasic and biphasic solutions can confirm the formation of the major complexes, thanks to the correlation between the fluorescence lifetime and the number of water molecules potentially present in the inner coordination sphere of the metal ions. Fluorescence spectra can be also obtained at increasing temperature to study complexation thermodynamics and investigate complex stability at experimental conditions closer to industrial applications.
References
External links
Partitioning and Transmutation for waste management
The sustainability of used nuclear fuel management
Nuclear fuels
Uranium
Plutonium
Actinides
Nuclear reprocessing
Separation processes by phases
Liquid-liquid separation | Advanced reprocessing of spent nuclear fuel | [
"Chemistry"
] | 4,364 | [
"Separation processes",
"Separation processes by phases",
"Liquid-liquid separation"
] |
64,345,991 | https://en.wikipedia.org/wiki/Screen-printed%20electrodes | Screen-printed electrodes (SPEs) are electrochemical measurement devices that are manufactured by printing different types of ink on plastic or ceramic substrates, allowing quick in-situ analysis with high reproducibility, sensitivity and accuracy. The composition of the different inks (carbon, silver, gold, platinum) used in the manufacture of the electrode determines its selectivity and sensitivity. This fact allows the analyst to design the most optimal device according to its purpose.
The evolution of these electrochemical cells arises from the need to reduce the size of the devices, that implies a decrease of the sample volume required in each experiment. In addition, the development of SPEs has enable the reduction of the production costs.
One of the principal advantages is the possibility of modifying the screen-printed electrodes, modifying the composition of its inks by adding different metals, enzymes, complexing agents, polymers, etc., which is useful for the preparation of multitude electrochemical analyses.
Description
Screen printing is one of the oldest methods of reproduction. The screen-printed electrodes (SPEs) are presented as a single device in which there are three different electrodes:
Working electrode. Their response is sensitive to the analyte concentration.
Reference electrode. It allows the application of a known potential, which is independent of the analyte and other ions concentration. Its potential is constant, and the working electrode potential is measured against it.
Auxiliary or counter electrode. It is the electrode that completes the circuit of the three-electrode cell, as it allows the passage of current. It enables the analysis of processes in which electronic transfer takes place.
The three electrodes could be printed on different types of substrates (plastic or ceramic) and could be manufactured with a great variety of inks. The most common inks are those composed of silver and carbon, however, they can be based on other metals such as platinum, gold, palladium or copper. In addition, the electrodes can be modified with enzymes, metallic nanoparticles, carbon nanotubes, polymers or complexing agents. The electrode ink composition is chosen according to the final application and the selectivity and sensitivity required for the analysis.
The electrode manufacturing process involves the sequential deposition of different layers of conductive and/or insulating inks on the substrates of interest. The process consists of several stages:
Film deposition usually on plastic or ceramic.
Drying of the printed films, thus eliminating possible organic solvents needed to produce a proper adhesion. Drying can be done in an oven at temperatures between 300 and 1200 °C, or in cold cured ink with a subsequent UV light photocuring process.
The process can be repeated if complex structures are required using the appropriate material for the specific design.
On the other hand, as mentioned above, the most commonly used inks are silver and carbon, therefore, their printing and manufacturing characteristics should be highlighted:
Silver ink. This ink acts as a conductor, while the working electrodes are printed mainly with graphite inks, although gold, platinum and silver inks are also used. Some ink components induce differences in detection and analysis.
Silver/silver chloride ink. Silver/silver chloride is an industry preferred reference electrode because it has stable electrochemical potential under numerous measurement conditions. This makes silver/silver chloride ink a good choice for a variety of medical and industrial applications that require conductive ink, such as biometric monitoring or heavy metal detection. The properties of the ink can be adjusted by changing the ratio of silver to silver chloride.
Carbon ink. The electrodes composition is usually confidential information from the manufacturing company, however, there are key elements for the electrodes composition such as binders, used to improve the affinity of the substrate and ink, and solvents employed to improve the viscosity for the printing process. The type, size or charge of the graphite particles and the printing and drying conditions could affect the electron transfer and the analytical yield of the carbon sensors.
Gold ink. Gold ink is currently generating more interest due to the formation of self-assembling monolayers (SAM) by means of strong Au-S bonds.
Advantages and applications
Screen-printed electrodes offer several advantages such as low cost, flexibility of their design, great reproducibility of the process and of the electrodes obtained, the possibility of manufacturing them with different materials and the wide capacity of modification of the work surface. Another advantage is the possibility of connection to a portable instrumentation allowing the in-situ determination of specific analytes. In addition, screen-printed electrodes avoid tedious cleaning processes.
Currently, they are used as a support to produce portable electrochemical biosensors for environmental analysis. Some applications are:
Phenolic compounds: their quick detection from electrochemical biosensors based on SPE is a challenge because they easily penetrate plants, animals and humans through their membranes and skins, producing toxic side effects.
Nitrite and phosphate: their detection at low levels is of great importance due to their toxicity. SPEs capable of detecting nitrite and phosphate have been designed. Micro-electrodes combined with screen-printing technology have been used to manufacture nitrite-sensitive sensors.
Pesticides: Organophosphate pesticides are harmful to humans and animals because they inhibit the activity of many enzymes. Nowadays, inhibition biosensors based on SPEs have emerged.
Herbicides: Drinking water is contaminated due to the increased use of herbicides. To achieve selective detection, the most common method is the immunoassay which, combined with SPEs, is detected directly avoiding the cleaning and reuse of active components.
Heavy metal detection: simple and economic devices are needed for in-situ detection of heavy metals, due to their high toxicity even at low concentrations. The most common toxic metal ions are Pb (II) and Hg (II)
Pb (II): Sensors for lead detection are usually modified with certain materials (carbon, bismuth or gold among others) to increase their sensitivity. To improve their detection, these modifiers are attached to the SPEs surface. The most widely used is bismuth due to its great yield and improved sensitivity, reaching the level of parts per billion (ppb).
Hg (II): mercury is the most problematic pollutant. Generally, gold electrodes are used for detection due to their high affinity. However, the use of gold electrodes produces structural changes on the surface caused to the formation of amalgam. Commercially available screen-printed gold electrodes make mercury measurements in water easier because no electrode preparation is required.
Generation of SERS substrates. During the last years SPE have been used to generate in-situ SERS substrates for analytical purposes.
On the other hand, a correct manufacturing process is important to avoid low reproducibilities, to encourage mineral binders or insulating polymers that achieve a high resistance of SPE, and to use inks that do not significantly affect the kinetics of the reactions that take place. In manufacturing, surface treatments are used to remove organic contaminants from the ink. This improves their electrochemical properties by increasing the surface roughness.
References
Electrodes
Biosensors | Screen-printed electrodes | [
"Chemistry",
"Biology"
] | 1,458 | [
"Electrochemistry",
"Electrodes",
"Biosensors"
] |
64,346,404 | https://en.wikipedia.org/wiki/Ogataea | Ogataea is a genus of ascomycetous yeasts in the family Saccharomycetaceae. It was separated from the former genus Hansenula via an examination of their 18S and 26S rRNA partial base sequencings by Yamada et al. 1994.
The genus name of Ogataea is in honour of Koichi Ogata (x - 1977), who was a Japanese microbiologist from the Department of Agricultural Chemistry, Faculty of Agriculture, at Kyoto University. It was stated in the journal; "The genus is named in honor of the late Professor Dr. Koichi Ogata, Department of Agricultural Chemistry, Faculty of Agriculture, Kyoto University, Kyoto, Japan, in recognition of his studies on the oxidation and assimilation of methanol (C1 compound) in methanol-utilizing yeasts."
The genus was circumscribed by Yuzo Yamada, Kojiro Maeda and Kozaburo Mikata in Biosc., Biotechn. Biochem. vol.58 (Issue 7) on page 1253 in 1994.
Diagnosis
Like other yeasts, also the species within the genus Ogataea are single-celled or build pseudohyphae of only a few elongated cells; true hyphae are not formed.
They are able to reproduce sexually or asexually. The latter case happens with a cell division by multilateral budding on a narrow base with spherical to ellipsoidal budded cells. In the sexual reproduction the asci are deliquescent and may be unconjugated or show conjugation between a cell and its bud or between independent cells. Asci produce one to four, sometimes more, ascospores which are hat-shaped, allantoid or spherical with a ledge. The species are homothallic or infrequently heterothallic.
Ogataea cells are able to ferment glucose or other sugars and some species assimilate nitrate. All known species are able to utilize methanol as carbon source. The predominant ubiquinone is coenzyme Q-7 and the diazonium blue B test is negative. Some species are used and cultured for microbiological and genetic research e.g. Ogataea polymorpha, Ogataea minuta or Ogataea methanolica. Ogataea minuta (Wickerham) Y. Yamada, K. Maeda & Mikata is the type species for this genus.
Species
Ogataea consists of several species and is placed within the Saccharomycetales as a sister genus to Ambrosiozyma. Following Kurtzman et al. 2011 the genus consists of 31 species but also shows, that there are several more within the taxon that are part of the polyphyletic genus Candida.
Ogataea allantospora Péter, Tornai-Lehoczki & Dlauchy (2007)
Ogataea chonburiensis Limtong, Srisuk, Yongmanitchai, Yurimoto & Nakase (2008)
Ogataea corticis Nagatsuka, S. Saito & Sugiyama (2008)
Ogataea dorogensis (Péter, Tornai-Lehoczki, Fülöp & Dlauchy) Nagatsuka, S. Saito & Sugiyama (2008)
Ogataea falcaomoraisii Morais, Teixeira, J.M. Bowles, Lachance & C.A. Rosa (2004)
Ogataea ganodermae F.Y Bai & Z.H. Ji (2008)
Ogataea glucozyma (Wickerham) Y. Yamada, K. Maeda & Mikata (1994)
Ogataea henricii (Wickerham) Y. Yamada, K. Maeda & Mikata (1994)
Ogataea kodamae (van der Walt & Yarrow) Mikata & Y. Yamada (1995)
Ogataea methanolica (Makiguchi) Kurtzman & Robnett (2010)
Ogataea methylivora (Kumamoto & Seriu) Kurtzman & Robnett (2010)
Ogataea minuta (Wickerham) Y. Yamada, K. Maeda & Mikata (1994)
Ogataea naganishii (K. Kodama) Kurtzman & Robnett (2010)
Ogataea nakhonphanomensis Limtong, Srisuk, Yongmanitchai, Yurimoto & Nakase (2008)
Ogataea neopini Nagatsuka, S. Saito & Sugiyama (2008)
Ogataea nitratoaversa Péter, Tornai-Lehoczki & Dlauchy (2008)
Ogataea nonfermentans (Wickerham) Kurtzman & Robnett (2010)
Ogataea paradorogensis Nakase, Ninomiya, Kawasaki & Limtong (2008)
Ogataea philodendri (van der Walt & Scott) Y. Yamada, K. Maeda & Mikata (1994)
Ogataea pilisensis (Péter, Tornai-Lehoczki, Fülöp & Dlauchy) Kurtzman & Robnett (2010)
Ogataea pini (Holst) Y. Yamada, M. Matsuda, K. Maeda & Mikata (1995)
Ogataea polymorpha (Falcão de Morais & Dália Maia) Y. Yamada, K. Maeda & Mikata (1994)
Ogataea populialbae Péter, Tornai-Lehoczki & Dlauchy (2009)
Ogataea ramenticola (Kurtzman) Kurtzman & Robnett (2010)
Ogataea salicorniae (Hinzelin, Kurtzman & M.Th. Smith) Kurtzman & Robnett (2010)
Ogataea siamensis (Limtong, Srisuk, Yongmanitchai, H. Kawasaki, Yurimoto, Nakase & N. Kato) Limtong, Srisuk, Yongmanitchai, Yurimoto & Nakase (2008)
Ogataea thermomethanolica (Limtong, Srisuk, Yongmanitchai, Yurimoto, Nakase & N. Kato) Limtong, Srisuk, Yongmanitchai, Yurimoto & Nakase (2008)
Ogataea trehaloabstinens (Péter, Tornai-Lehoczki, Fülöp & Dlauchy) Nagatsuka, S. Saito & Sugiyama (2008)
Ogataea trehalophila (Phaff, M.W. Miller & Spencer) Kurtzman & Robnett (2010)
Ogataea wickerhamii (Capriotti) Y. Yamada, M. Matsuda, K. Maeda & Mikata (1995)
Ogataea zsoltii (Péter, Tornai-Lehoczki, Fülöp & Dlauchy) Nagatsuka, S. Saito & Sugiyama (2008)
References
Saccharomycetaceae
Yeasts
Yeasts used in brewing | Ogataea | [
"Biology"
] | 1,495 | [
"Yeasts",
"Fungi"
] |
64,347,405 | https://en.wikipedia.org/wiki/Composite%20methods%20for%20structural%20dynamics | Composite methods are an approach applied in structural dynamics and related fields. They combine various methods in each time step, in order to acquire the advantages of different methods. The existing composite methods show satisfactory accuracy and powerful numerical dissipation, which is particularly useful for solving stiff problems and differential-algebraic equations.
Definitions
After spatial discretization, structural dynamics problems are generally described by the second-order ordinary differential equation:
.
Here , and denote the displacement, velocity and acceleration vectors respectively, is the mass matrix, is the damping matrix, collects the internal force, and is the external load. At the initial time , the initial displacement and velocity are supposed to be given as and , respectively, and the initial acceleration can be solved as
.
For numerical analysis, the overall time domain is divided into a series of time steps by , , , , , . Taking the step
( is the step size), the main concept of composite methods is to subdivide the current step to several sub-steps , , , and to use different numerical methods in each sub-step.
Although there are lots of available methods, see the review, the existing composite methods basically employ the combination of the trapezoidal rule and linear multistep methods. However, to acquire at least second-order accuracy and unconditional stability, the scalar parameters of each method and the division of sub-steps need to be determined carefully.
Two examples of composite method
Two-sub-step Bathe method
The Bathe method is a two-sub-step method. In the first sub-step (, ), the trapezoidal rule is used as:
In the second sub-step (), the 3-point Euler backward method is employed as
For nonlinear dynamics, that is, the internal force is a nonlinear function with respect to , the Newton-Raphson iterations can be used to solve the nonlinear equations per step. The parameter is usually set as and in practice.
The Bathe method is second-order accurate and unconditionally stable from linear analysis. Besides, this method can provide strong numerical dissipation for high-frequency content, which is helpful to damp out the stiff components and enhance the stability for nonlinear dynamics.
On this basis, to acquire prescribed degree of numerical dissipation, the -Bathe method was developed by replacing the 3-point Euler backward method in the second sub-step with a general formula:
The parameters are selected as recommended
With the set of parameters, the -Bathe method can also achieve second-order accuracy and unconditional stability. Moreover, by adjusting the parameter , this method can provide tunable degree of numerical dissipation. The method with a smaller shows stronger numerical dissipation, but lower accuracy in the low-frequency content. When , it is equivalent to the original Bathe method with .
Three-sub-step composite method
Following the idea of the Bathe method, the three-sub-step composite methods that use the trapezoidal rule in the first two sub-steps were also discussed. They divides the current step into , and , and generally, the first two sub-steps are set as equal size, that is . In the first two sub-steps, the trapezoidal rule is used, as
and
In the last sub-step, a general formula is utilized as
For this method, Li et al. offered two optimal set of parameters, as
Here is assumed, and is the minimum value that satisfies .
The resulting two sub-families are all second-order accurate, unconditionally stable, and can provide tunable numerical dissipation by adjusting . They become the same when . When , the sub-family with shows better amplitude and period accuracy than the -Bathe method under the same computational costs, and the sub-family with further improves the period accuracy at the cost of lower amplitude accuracy.
Analysis
In structural dynamics, the test model for property analysis is the single degree-of-freedom homogeneous equation, as
Here is the damping ratio and is the natural frequency. Applying the composite method to the test model yields the compact scheme
Here and is the amplitude matrix, which governs the properties of a method. Generally, has one zero characteristic root and a pair of conjugate complex roots , which can be solved from
Here is the trace of and is the sum of second-order principal minors of . They are functions of , , and the parameters of the method.
Accuracy
From the compact scheme, the difference equation only with respect to the displacement can be written as
The local truncation error is defined as
The method is called th-order accurate if .
Stability
For physically stable systems (, ), the method can give stable solutions if the spectral radius . A method is called unconditionally stable if the condition is satisfied for any
, otherwise it is called conditionally stable. The spectral radius at the high-frequency limit, i.e. , is denoted as , which is usually employed to indicate the degree of numerical dissipation, as used above.
Amplitude decay ratio and period elongation ratio
In addition to the accuracy order, the amplitude decay ratio and period elongation ratio are also usually evaluated to measure the amplitude and period accuracy in the low-frequency content. The exact solution of the test model is
Here and are constants determined by the initial conditions. The numerical solution can be also expressed as a similar form, as
Likewise, and are also determined by the initial conditions and they should be close to and respectively for a convergent method. The damping ratio and frequency can be obtained from the norm and phase , as
Here is called the amplitude decay ratio, and () is called the period elongation ratio.
Example
Consider the Bathe method, and have the form as
Here the undamped case, i.e. , is considered for simplicity. One can check that this method can satisfy the conditions of second-order accuracy and unconditional stability. With and , the spectral radius, amplitude decay ratio, and period elongation ratio are shown here. It can be observed that this method can provide good amplitude and period accuracy in the low-frequency content, while strong numerical dissipation, as , in the high-frequency content.
See also
Runge-Kutta method
List of Runge–Kutta methods
Numerical ordinary differential equations
Linear multistep method
Lie group integrator
References
Numerical analysis
Numerical differential equations | Composite methods for structural dynamics | [
"Mathematics"
] | 1,316 | [
"Mathematical relations",
"Computational mathematics",
"Approximations",
"Numerical analysis"
] |
62,955,264 | https://en.wikipedia.org/wiki/Redmi%20Note%209 | Redmi Note 9 is a line of Android-based smartphones as part of the Redmi Note series by Redmi, a sub-brand of Xiaomi Inc.
The smartphone was succeeded by Redmi Note 10, an upgraded version released in March, 2021.
Specifications
Hardware
Design
Note 9
The Note 9/10X 4G measures and weighs which is heavier than usual for a 6.53-inch phone. The curved (slippery) back feels like glass, the front is made of Gorilla Glass 5, and the frame is made of plastic. The bottom half is heavier to prevent the device from tipping over and falling. The bezels and the camera bump are small.
In addition to the touchscreen, it has a power button and a volume up/down button located on the right side, an IR blaster on the top, and a USB-C port, a downward-firing speaker, and a headphone jack on the bottom. It has a hole punch in the left corner and a fingerprint scanner in the rear.
The Note 9/10X 4G has three colour options: Forest Green, Midnight Grey, and Polar White.
Note 9S/Pro (India)
The Note 9S/Pro (India) measures and weighs . The curved (slippery) back and the front is made of Gorilla Glass 5, and the matte frame is made of plastic. The bezels are small, however, the phone does wobble because of a camera bump raising the phone. It is also splash-proof and has a P2i water repellent coating.
In addition to the touchscreen, it has a power/fingerprint scanner button and a volume up/down button located on the right side, microSD slot in the left side, an IR blaster on the top, and a USB-C port, a downward-firing speaker, and a headphone jack on the bottom. It has an earpiece above the display, and a notification LED.
The Note 9S/Pro (India) has three colour options: Aurora Blue, Glacier White, and Interstellar Gray.
Note 9 Pro (global)/Pro Max
The Note 9 Pro (global) measures . For the Note 9 Pro Max, it measures . Both of them weigh . The curved back with a gloss finish and the front is made of Gorilla Glass 5, and the frame is made of plastic. The bezels, which are always painted in black, are small (except the chin at the bottom), however, the phone does wobble because of a camera bump raising the phone. It is also splash-proof and has a P2i water repellent coating.
In addition to the touchscreen, it has a power/fingerprint scanner button and a volume up/down button located on the right side, SIM card and microSD slot in the left side (triple slot), an IR blaster on the top, and a USB-C port, a downward-firing speaker, and a headphone jack on the bottom. It has an earpiece and a notification LED above the display.
The Note 9 Pro (global)/Pro Max has three color options: Tropical Green, Glacier White, and Interstellar Gray.
POCO M2 Pro
The POCO M2 Pro measures and weighs . The curved back with a gloss finish and the front is made of Gorilla Glass 5, and the matte frame is made of plastic. It has a striped pattern on the phone that takes up two-thirds of the rear, which resembles the original Google Pixel.
In addition to the touchscreen, it has a recessed power/fingerprint scanner button and a volume up/down button located on the right side, microSD slot, an IR blaster, and a USB-C port, a downward-firing speaker, and a headphone jack.
The POCO M2 Pro has three colour options: Out Of The Blue, Green and Greener, and Two Shades of Black.
Chipset
The Note 9 uses the octa-core MediaTek Helio G85 containing 2 2GHz Cortex-A75 core, 6 1.8GHz Cortex-A55 core, and an 1GHz Mali-G52 MC2 GPU), which is a small revision of the MediaTek Helio G80. The GPU's difference is the GPU clock at 950 MHz on the MediaTek Helio G80, and 1 GHz on the MediaTek Helio G85.It is also known as decent gaming processors.
The rest of the series uses the octa-core Qualcomm Snapdragon 720G which contains 22.3 GHz Kryo 465 Gold core, 6 1.8GHz Kryo 465 Silver core, and an Adreno 618 GPU.
Display
The Note 9 has a 2340x1080 1080p (395ppi with 19.5:9 aspect ratio), 16M colors, Gorilla Glass 5, and IPS LCD display with 1242:1 contrast ratio, 370 nits of brightness with 100% brightness, and up to 466 nits with Auto mode turned on.
The rest of the series has a slightly larger display, at 2400x1080 with a 20:9 aspect ratio, rated for 1500:1 contrast ratio and 450nits of brightness, and has support for HDR10. In the POCO M2 Pro, there is a daylight mode that triggers once the phone detects bright lighting. The mode increases the saturation and contrast of the display. The mode reduces colour accuracy and makes the colours unnatural, especially when playing games or looking at pictures.
The Note 9S/Pro (India) has 421nits of brightness with 100% brightness, up to 575nits of brightness with Auto mode turned on, and 1369-1389:1 contrast ratio. The Note 9 Pro (global)/Pro Max has 456 nits of brightness with 100% brightness, up to 616nits of brightness with Auto mode turned on, and a 1265-1285:1 contrast ratio.
Camera
The Note 9 uses a quad rear camera array, which is a 48MP ƒ/1.8 26 mm 1/2" 0.8 μm main camera with PDAF, an 8MP ƒ/2.2 13 mm 1/4" 1.12 μm 118° ultra-wide camera, a 2MP ƒ/2.4 1/5" 1.75 μm macro camera with autofocus, and an 2MP ƒ/2.4 depth sensor camera. It also has a 13 MP ƒ/2.3 29 mm 1/3.1" 1.12 μm front camera. It can shoot at 1080p/30 fps with the rear camera and the front camera.
The Note 9S/Pro (India)/POCO M2 Pro has the macro camera upgraded to 5MP, and the ultra-wide camera slightly wider at 119˚. It also has a 16MP f/2.5 1/3.06" 1 μm front camera, and can shoot at 4K/30 fps, 1080p/60/120 fps, and 720p/960 fps with the rear camera, 1080p/120 fps with the front camera, and has gyro-EIS.
The Note 9 Pro (global)/Pro Max has the main camera upgraded to a 64MP ƒ/1.9 26 mm 1/1.72" 0.8 μm main camera, and the Note 9 Pro Max has a 32MP 1/2.8" 0.8 μm front camera.
Battery
The entire line uses a non-removable 5020mAh Li-Po battery, except for the POCO M2 Pro which uses a slightly smaller non-removable 5000mAh Li-Po battery. The Note 9/9S/Pro (India) has 18 W fast charging, the Note 9 Pro (global) and the Note 9 Pro Max has 30 W fast charging, and the POCO M2 Pro has 33 W fast charging.
Software
User interface
The series is powered by Android. Among other features, the software allows users to maintain customized home screens, which can contain shortcuts to applications and widgets for displaying information. Shortcuts to frequently used applications can be stored on a dock at the bottom of the screen. A tray accessed by dragging from the top of the screen allows users to view notifications received from other apps. It contains toggle switches for commonly used functions.
The series uses MIUI 12.5.1 based on Android 11. MIUI 12.5 has a minimalistic design and some elements of the original Android, such as the toggle switches in the notification tray, and the app drawer in some markets. The app drawer can be customized, such as sorting different apps into categories, and the colour of the background. MIUI 12.5 also supports dark mode, making the system background turn black, and icons darken as well, reading mode, and night mode. The notification tray can be customized, such as the looks of the notification cards. MIUI 12.5 also has per-app background activity control. The task switcher shows all of the opened apps in two columns. MIUI 12.5 has split-screen capability accessible through pressing and holding an application in the task switcher.
Features and apps
MIUI 12.5 is a slight improvement over MIUI 12 and comes as an intermediary between MIUI 12 and the forthcoming MIUI 13. It has notification and alarm sounds that change their sounds depending on the time. MIUI 12.5 continues to have Mi's own gallery, music, video player, and document viewer. There is a paid option for streaming in the music and video player in some markets. MIUI 12.5 also has a Security app, which scans for malware, clears RAM space, manages permissions, quota usage, and battery-draining apps. In some countries, the first-party applications will show ads. This is one way Xiaomi manages to lower the cost of their phones.
Android fork
The Redmi Note 9 series have gone through 3 major Android updates, those being Android 10, Android 11 and the last major release being Android 12.
For Xiaomi's interface, or in general terms used to describe other brands interfaces as Android fork, those being MIUI 11, MIUI 12, MIUI 13 (the last one for EEA variant and the last one for Redmi Note 9/Redmi 10X 4G too.) and the last fork release being MIUI 14 (on Global,Indian,Indonesian and Turkey variant.).
Reception
Redmi Note 9
GSMArena rated the phone 3/5 stars. They praised the sturdy design, the battery life, the Night Mode, the AF on the macro camera, the headphone jack, microSD card slot, the IR blaster, and the feature-rich OS. They criticized the mediocre display, the performance, the overall camera quality, the lack of 4K recording, the slow UI, and the charging speed.
Redmi Note 9S/Pro/Pro Max
TechRadar reviewer Aakash Jhaveri and Tom Bedford gave the Note 9S / Pro (India) a 4/5 star rating, stating that the phone was a "killer deal for the price" despite the conservatism of the Note 9S (no 90 Hz or more display, no next-gen cameras, no 30 W+ fast charging, and no unique design). They praised the long battery life, the performance. They criticized the buggy pre-release software, the notifications from the pre-installed apps, and the speaker.
GSMArena rated the series (except Redmi Note 9) 3.8/5 stars. They praised the screen, the battery, the performance for the price, good image quality for the cost, the design, and the availability of NFC (Note 9 Pro (global) / Pro Max only). They criticized the uneven lighting around the hole punch, the lack of NFC (Note 9S/Pro Indian version), and the charging speed (Note 9S/Pro Indian version).
References
External links
Phablets
Note 9
Mobile phones introduced in 2020
Mobile phones with multiple rear cameras
Mobile phones with 4K video recording
Mobile phones with infrared transmitter
Discontinued smartphones | Redmi Note 9 | [
"Technology"
] | 2,535 | [
"Crossover devices",
"Phablets"
] |
62,955,446 | https://en.wikipedia.org/wiki/Kurt%20Koffka%20Medal | The Kurt-Koffka Medal, Kurt Koffka Medal, Kurt Koffka Award, or Koffka Prize is an annual, international award bestowed by Giessen University's Department of Psychology for "advancing the fields of perception or developmental psychology to an extraordinary extent". The prize commemorates the German psychologist Kurt Koffka, a pioneer of Gestalt Psychology, in particular in the fields of perception and developmental psychology. Koffka worked at Giessen University for 16 years, from 1911 to 1927. The medal was first awarded in 2007.
The medal is notable among psychologists.
History
Kurt Koffka (18 March 1886 – 22 November 1941) was a German psychologist. He was born and educated in Berlin. Along with Max Wertheimer and his close associate Wolfgang Köhler they established Gestalt psychology. Koffka's wide-ranging interests included perception, hearing impairments in brain-damaged patients, interpretation, learning, and the extension of Gestalt theory to developmental psychology.
Each year since 2006, a committee of Giessen University Department of Psychology has sought nominations and decided on the recipient(s) of the award. The first medal was awarded in 2007 to Martin "Marty" Banks. The one exception was 2020, when the award ceremony was deferred to 2021 because of the COVID-19 pandemic.
Description of the medal
The medal is bronze. The front (obverse) side is shown in the info box. A recipient's name is engraved on the outer ring at the bottom. The other side is an embossed version of the seal of the university.
Nominations
Nomination forms are sent by the members of the Committee to large numbers of individuals, usually in September the year before the award is made. These individuals are generally prominent academics working in a relevant area.
Selection
The members of the Committee prepare a report reflecting the advice of experts in the relevant fields.
Prizewinners
Source: Justus Liebig University, Giessen
2007: Martin Banks
2008: Claes van Hofsten
2009: Janette Atkinson and Oliver Braddick
2010: Roberta Klatzky
2011: Concetta Morrone and David Burr
2012: Sandra Trehub
2013: Stuart Anstis
2014: Elizabeth Spelke
2015: Roland S. Johansson
2016: Andrew N. Meltzoff
2017: Jan J. Koenderink and Andrea J. van Doorn
2018: Karen E. Adolph
2019: Dan Kersten
2020: No award
2021: Linda B. Smith
2022: Ted Adelson
2023: Richard Aslin
2024: Mary Hayhoe
Gender balance of recipients
Unlike some science awards, such as the Nobel Prize, the Kurt-Koffka medal has a good gender balance of recipients (by 2023, 11 men and 9 women).
See also
Nobel Prize
Fields Medal
Ig Nobel Prize
List of prizes known as the Nobel of a field
Lists of science and technology awards
List of psychology awards
References
Academic awards
International awards
Science and technology awards
German science and technology awards
University of Giessen
Perception
Psychology awards | Kurt Koffka Medal | [
"Technology"
] | 626 | [
"Science and technology awards",
"International science and technology awards"
] |
62,957,904 | https://en.wikipedia.org/wiki/Parasaurus | Parasaurus (meaning "near lizard") is a genus of pareiasaur known from fossils collected in the Kupferschiefer in Germany (Hesse, Thuringia and Lower Saxony), dating to the Late Permian (Wuchiapingian). The type species, Parasaurus geinitzi, described by Hermann von Meyer in 1857, was the first pareiasaur ever described. The seven known specimens were redescribed in 2008.
Discovery and naming
As early as 1848, pareiasaur fossils have been reported from Germany; some of these fossils may have belonged to Parasaurus. It was not until 1857 when von Meyer described these fossils and created the Parasaurus genus. von Meyer classified Parasaurus as a reptile but it was classified as a pareiasaur when the family was created in 1888. Lee (1997) classified Parasaurus as a nomen dubium. In 2008, Tsuji and Müller re-evaluated the genus.
Description
Parasaurus was small for a pareiasaur, only around long. Axial osteoderms appear to be absent. The skull surface is pitted, with small spike-like horns on the supratemporal and quadratojugal.
Phylogeny
Below is a cladogram from Tsuji et al. (2013):
Paleoenvironment
The Kupferschiefer is a marine unit that forms part of the Zechstein, a sequence of rocks formed on the edge of the Zechstein Sea, a large inland shallow sea that existed in Northern Europe during the Late Permian. The environment at the time of deposition is considered to have been semi-arid. The terrestrial flora of the Zechstein is dominated by conifers, with seed ferns also being common, while taeniopterids, ginkgophytes and sphenophytes are rare. Other terrestrial vertebrates found in the Kupferschiefer and lower Zechstein include the gliding weigeltisaurid reptiles Weigeltisaurus and Glaurung, the archosauromorph reptile Protorosaurus, the cynodont Procynosuchus, and indeterminate captorhinids, dicynodonts, and dissorophid temnospondyls.
References
Pareiasaurs
Nomina dubia
Fossil taxa described in 1857
Prehistoric reptile genera
Lopingian life
Wuchiapingian life | Parasaurus | [
"Biology"
] | 508 | [
"Biological hypotheses",
"Nomina dubia",
"Controversial taxa"
] |
62,960,766 | https://en.wikipedia.org/wiki/Salisbury%20cutlery%20industry | The Salisbury cutlery industry was active in the city of Salisbury, England from late Medieval times until the start of the 20th century. While production was not on the scale of the Sheffield cutlery industry, the Salisbury cutlers were noted for the quality of their products. A reason given for success of the industry was the fineness of the steel produced, resulting from the quality of the local water, which came from the surrounding chalk downland. The Salisbury Museum has a collection of Salisbury-made cutlery and a scrapbook of trade-cards that were collected by the Salisbury cutlers, James and Thomas Goddard, who were cutlers to George III.
References to the industry
Poets sang the praise of the industry. John Gay (1685–1735) in an epistle to Lord Burlington extolls Salisbury:
A couplet from the Bath Guide c.1820 runs:
While a traditional saying attributes Salisbury’s fame to:
The earliest reference to a cutler working in Salisbury was in c1270-80 when "Sebode the Cutiller, held a tenement in Brown Street."
John Aubrey wrote that Salisbury was 'ever-famous' for the manufacture of razors, scissors, and knives. Late 18th-century directories list six cutlers in Salisbury, and in 1790 it was said that the city was noted for the manufacture of scissors. The trade continued throughout the 19th century. George III and the Duchess of Kent are said to have patronised members of the Botly family, cutlers of the Market Place. It was the custom to meet the London and Exeter coach and display cutlery to the passengers.
James Macklin, a working cutler who was Mayor of Salisbury at the outbreak of the First World War, was knighted for his work for the war effort.
References
Sources
Haskins C. (1912) Ancient Trade Guilds and Companies of Salisbury.
Moore C.N. (undated but ?1971) The Salisbury Cutlery Industry, Wiltshire Industrial Archaeology, the magazine of the Salisbury and South Wilts Industrial Archaeology Society, No4, pp.7-14.
External links
Salisbury cutlery at The Salisbury Museum
Metallurgical industry of the United Kingdom
Cutlery | Salisbury cutlery industry | [
"Chemistry"
] | 441 | [
"Metallurgical industry of the United Kingdom",
"Metallurgical industry by country"
] |
62,960,782 | https://en.wikipedia.org/wiki/Heinz%20Raether | Heinz Artur Raether (14 October 1909 — 31 December 1986) was a German physicist. He is best known for his theoretical and experimental contributions to the study of surface plasmons, as well as for Kretschmann-Raether configuration, a commonly-used experimental setup for the excitation of surface plasmon resonances.
From 1944 to 1946 he was a professor of physics at the University of Jena at the Physikalisches Institut. Here he dealt with electron physics, electron microscopy, electron interference and gas discharges.
In 1951, he took over the management of the Institute for Applied Physics at the University of Hamburg. After the development of the transistor, he focused on solid state physics. His work during this period concerned the structure and growth of crystals. Later he became interested in the collective behavior of the electrons of a crystal, the solid-state electron plasma.
In gas discharge physics, he devoted himself to the ignition process, especially the formation of the spark channel, the initial phase of electrical breakdown. In 1963 he was elected a full member of the Göttingen Academy of Sciences. In 1979 he was elected a member of the Academy of Sciences Leopoldina.
Selected publications
Articles
Books
See also
Raether limit
Surface plasmon polariton
Townsend discharge
References
1909 births
1986 deaths
Condensed matter physicists
Electrical breakdown
Optical physicists
People associated with electricity
Scientists from Nuremberg
German plasma physicists
Plasmonics
Academic staff of the University of Hamburg
Academic staff of the University of Jena
20th-century German physicists
Nanophysicists | Heinz Raether | [
"Physics",
"Chemistry",
"Materials_science"
] | 313 | [
"Plasmonics",
"Physical phenomena",
"Condensed matter physicists",
"Surface science",
"Electrical phenomena",
"Condensed matter physics",
"Electrical breakdown",
"Nanotechnology",
"Solid state engineering"
] |
62,960,859 | https://en.wikipedia.org/wiki/Pete%20Tomlin | Pete Tomlin is an expert in transit signalling systems, who was employed by both the Toronto Transit Commission, the New York City Transit Authority, Hong Kong and the London Underground.
Signalling systems
Tomlin was responsible for installing the signal system on London's Jubilee line, in 1997, and the West Rail and Ma On Shan subway lines in Hong Kong, before coming to Toronto to upgrade the signal system on the Yonge-University Line.
The New York's MTA Andy Byford hired Tomlin in January 2019, who had worked under him in Toronto. Byford described his hiring of Tomlin as a "coup", because multiple other systems had wanted to hire him.
According to the New York Daily News it was his expertise in upgrading the signal infrastructure subways use that put him in demand. Many major cities share the problem of their most used lines approaching or occasionally exceeding their maximum passenger carrying capacity. Improving the signals system allows trains to run closer together and more frequently, increasing a subway line's passenger capacity. It can postpone the need for new parallel lines to be installed.
Tomlin was hired during the middle of a hiring freeze.
Tomlin has overseen modernization of the signal systems of both London and Hong Kong's subway systems, prior to coming to Toronto.
In describing the challenge of gradually replacing a subway line's signals system, while it is still in use, Tomlin said “A colleague of mine once described it like … conducting open-heart surgery on a 100-year-old person while he’s eating his lunch.”
Byford repeatedly clashed with Governor Andrew Cuomo, and resigned on January 15, 2020. Tomlin resigned nine days later, on January 24, 2020.
References
Electrical engineers
Year of birth missing (living people)
Living people | Pete Tomlin | [
"Engineering"
] | 360 | [
"Electrical engineering",
"Electrical engineers"
] |
62,964,007 | https://en.wikipedia.org/wiki/Quarter%20minus | Quarter minus is a type of construction aggregate that is usually made from crushed basalt (but can be made of other rock types) from which the crushed rock product is not any bigger than 1/4" in diameter. The quarter minus rock size can consist of rock in diameter as big as 1/4" in size and "fines" (anything smaller than the maximum allowable rock size (which in this case is 1/4), even as small as stone dust). Any aggregate with the name "minus" can contain up to 80% fines. Quarter minus is mostly used as filler aggregate for bigger aggregate, empty space between two different sized aggregate, vehicle parking grade, and landscape surfaces. A positive of using quarter minus as a landscape aggregate is that it does not provide a home for pests and does not decompose like other landscape aggregates like wood-chips, for example.
References
Building materials
Pavements
Stone (material) | Quarter minus | [
"Physics",
"Engineering"
] | 192 | [
"Building engineering",
"Construction",
"Materials",
"Building materials",
"Matter",
"Architecture"
] |
62,965,775 | https://en.wikipedia.org/wiki/Thomas%20Lecuit | Thomas Lecuit, born 4 October 1971 in Saumur, is a French biologist specializing in the emergence of forms or morphogenesis. He is a professor at the Collège de France, holding the Dynamics of Life Chair. He leads a research team at the Institut de Biologie du Développement de Marseille (IBDM), and the Turing Centre for Living Systems, an interdisciplinary centre dedicated to the study of living organisms.
Biography
Thomas Lecuit grew up in Saumur, from medical parents who gave him a broad education, open to the arts, the humanities and science. He develops early a marked attraction for the things of nature, which arouse his curiosity. After a scientific baccalaureate (1989) he began studies in the preparatory class at the Lycée Sainte Geneviève, and in 1991 he entered the École Normale Supérieure.
In 1993-1994, he completed a decisive research internship at the Rockefeller University in New York under the direction of Claude Desplan, who introduced him to the world of research.
Pursuing his interest in the study of development, he completed his thesis at the EMBL in Heidelberg, under the supervision of Stephen Cohen. His work focuses on developmental genetics, that is, the way genes called morphogens orchestrate the identity of cells at a distance.
In 1998, Thomas Lecuit extended the study of developmental genetics to the analysis of its cellular bases during a postdoctoral fellowship at Princeton University with Eric Wieschaus, winner of the 1995 Nobel Prize in Physiology and Medicine. He is interested in cell dynamics and polarization, the starting point for a study of developmental dynamics.
Recruited at the CNRS in 2001 as a research fellow, he returned to France at the Institute of Developmental Biology in Marseille. He set up a research team on tissue architecture and plasticity which led him to unify genetic, cellular and physical approaches to morphogenesis.
His research focuses on the mechanical forces that generate cell and tissue movement and how developmental genes organize these forces. He was appointed director of research at the CNRS in 2006 and again in 2010, second class and then first class.
In 2014, Thomas Lecuit was elected to the French Academy of sciences. In 2016 he was appointed Professor at the Collège de France, holding the Dynamiques du Vivant chair. His inaugural lecture was delivered on 27 April 2017.
Thomas Lecuit's research is interdisciplinary and brings together biologists and physicists. Thomas Lecuit directs the Turing Centre for Living Systems in Marseille, an interdisciplinary centre dedicated to the study of life through collaborations between biologists, physicists, computer scientists and mathematicians.
Scientific contributions
Thomas Lecuit's scientific contributions address the general question of the origin of forms in biology and the nature of morphogenetic information.
To this end, he studies the Drosophila fly, a powerful model system for the study of development. The twentieth century was marked by the discovery of genetic determinisms of development, in particular the genes that define the cellular position information in an embryo, i.e. their spatial coordinates. In 1995-1998, Thomas Lecuit worked on a general way of organizing positional information by so-called morphogenic factors. Morphogens were first proposed by the mathematician Alan Turing in 1954, as factors organizing form according to purely physico-chemical principles of reaction-diffusion. Lewis Wolpert in 1969 and Francis Crick in 1971 proposed a more precise definition, as factors that form a concentration gradient at the origin of positional information. Thomas Lecuit shows that the growth factors of the BMP/Dpp and Wg/Wnt families are morphogens, acting at a distance, whose local concentration constitutes positional information that spatially organizes cell identity and limb axes. He focuses his attention on the close relationship between positional information and tissue growth from a dynamic point of view.
From 1998 onwards, as fluorescence imaging in living organisms develops, Thomas Lecuit studies the cellular basis of developmental dynamics. He is interested in the formation of the primordial tissue of the Drosophila embryo, a process called cellularization, and discovers the origins of membrane dynamics and its polarization.
Since 2001, Thomas Lecuit has been studying how genes orchestrate the cellular movements that cause changes in the shape of embryonic tissues. His research includes characterization of the physical principles of morphogenesis, along the lines of the work begun by d'Arcy Thompson in On Growth and Form (1917). His team first discovered the nature of the mechanical forces that cause tissue plasticity, namely the contractile forces that reshape the shape and cellular interactions and their division. They also study the nature of cohesive forces through intercellular adhesion. Contractile forces are organized in space and time and are polarized in privileged directions. Several articles reveal how embryonic position information orchestrates cell mechanics in space and time. This work is discussed in a broader perspective in several journals.
Since 2010, Thomas Lecuit and his colleagues have been highlighting the limits of a tradition that has largely seen development as the strict execution of a deterministic program governed by hierarchically regulated genes. Several studies indicate that it is also appropriate to consider statistical laws of organization, without hierarchy but with many feedbacks of a mechano-chemical nature. This work reveals the importance of self-organization during development and allows for a renewed definition of biological information that combines genetics, mechanics and geometry.
Awards
Elected member of the French Academy of sciences (2014)
Elected member of Academia Europaea (2014)
Liliane Bettencourt Prize for Life Sciences (2015)
Bronze medal (2006) then Silver medal (2015) from the CNRS
Grand Prix Victor Noury of the French Academy of sciences (2011)
Elected member of EMBO (2009)
Antoine Laccassagne Prize of the Collège de France (2009)
Schlumberger Foundation Awards for Education and Research (2004)
Officer of the Palmes Académiques
References
1971 births
People from Saumur
French biologists
Molecular biologists
Academic staff of the Collège de France
École Normale Supérieure alumni
Research directors of the French National Centre for Scientific Research
Members of the French Academy of Sciences
Members of Academia Europaea
Living people | Thomas Lecuit | [
"Chemistry"
] | 1,260 | [
"Molecular biologists",
"Biochemists",
"Molecular biology"
] |
62,966,467 | https://en.wikipedia.org/wiki/Relationships%20and%20health | There is empirical evidence of the causal impact of social relationships on health. The social support theory suggests that relationships might promote health especially by promoting adaptive behavior or regulating the stress response. Troubled relationships as well as loneliness and social exclusion may have negative consequences on health. Neurosciences of health investigate the neuronal circuits implicated in the context of both social connection and disconnection.
Models
Poor relationships have a negative impact on health outcomes. In 1985, Cohen and Wills presented two models that have been employed to describe this connection: the main effect model and the stress-buffering model.
The main effect model postulates that our social networks influence our psychology (our affect) and our physiology (biological responses). These three variables are thought to influence health, as described in Figure 1. This model predicts that increasing social networks may enhance general health. A possible mechanism by which social networks improve our health is through our behaviors: if our social network influences us to behave in a certain way that enhances our health, then it can be argued that our social network influences our health. For example, it has been demonstrated that higher social support improves our level of physical activity, which in turn has a positive effect on our health. It is unclear if this effect of social support is a threshold or a gradient. The difference between the two of them is that a threshold effect is a necessary amount of social support required to have a positive effect on health, on the opposite, a gradient effect can be described as a linear effect of the amount of social support on health, meaning that an increase of x amount of social support will result in an increase of y level of health.
The second model proposed by Cohen and Wills (1985) is the stress-buffering model. This model explains the effect of social networks on health when an individual is facing a stressful event. It predicts that, when facing a stressful event, an individual with a high perceived social support network will have better strategies, or resources, to face this event, hence resulting in better physical and mental health. Stress is an adaptive response when facing stressful events. A stressful event can be a life-threatening event (e.g., a disease, encountering a dangerous wild-animal) or a social-life event (e.g., a deadline, loss of a job, a conflict with a friend). This stress generates physiological or behavioral responses, depending on the event. However, this stress is not always "negative stress", it can also be "positive stress": Hans Selye distinguishes them as distress and eustress, respectively. As described in Figure 2, social support, more precisely perceived social support, has an impact on the appraisal processes and on the physiological and behavioral responses, according to the stress-buffering model. The appraisal processes refer to the way we evaluate an event as stressful or not (perceived stress or benign appraisal, respectively). The physiological and behavioral responses refer to what we call coping strategies. Those strategies are meant to help an individual to deal with a stressful event, but they can prove to be successful or not. Among different studies, this model has been used to understand how social support can be protective against infectious disease and also the link between social support and health outcomes in the specific case of homeless individuals, and both these studies demonstrate that social support has a positive impact on health outcomes, even if these two contexts seem highly different.
It has been argued that the main effect of social support is based on structural aspects of social relationships, like the social network size, and that the stress-buffering effect of social support is based on functional aspects of social relationships, like the quality of social support. This assumption has been quite well supported by the literature, but it remains unclear if other mechanisms of social relationships can have an impact on health too. Some studies have observed that there exist differences in this effect between males and females. In the specific domain of depression, it has been shown that some differences in the type of social support used to face depression are different between male and female participants, and this difference results in different coping strategies between gender. Indeed, men seem to need a social network that supports them for self-control, while women seem to need a social network that helps them recognize their problems. Thus, it seems important that the theoretical models include some other factors, such as gender, to explain the links between social networks and health outcomes. Despite this kind of criticism, both models have been supported by many studies.
Relationship quality and health
There is evidence that social integration is negatively linked to suicide and marital status is negatively linked to mortality rates from all-causes. Hibbard (1985) explored the link between social ties and health status by conducting a series of household surveys. Indeed, she found that people who have more social ties, more perception of control, and are most trustful with others tend to have better physical health. Thoits investigated how social ties can improve both mental and physical health. The results showed that social ties might influence emotional sustenance and promote active coping assistance. The other significant point of this research is that we can define two types of "supporters" able to provide different types of social support. Significant others (i.e., family, friends, spouse, etc.) tend to provide more instrumental support and emotional sustaining whereas experientially similar others (i.e., people who experienced the same life events than us) tend to provide more empathy, "role model" (a similar person looked like a model, a person to imitate) and active coping assistance.
Furthermore, social support can help us to regulate emotions above all when we are facing a stressful event. Probably one of the most famous studies on this field of investigation was conducted by Coan, Schaefer, and Davidson. In their study, they told married couples to go together in the laboratory. All couples reported a high level of marital satisfaction. The study aimed to evaluate the effect of hand-holding on the neural response to a threat. To create a stressful event, they informed the woman participant of each couple that she will receive moderate electric shocks. There were three experimental conditions: no hand holding, stranger hand holding, or spouse hand-holding. The findings suggested that both spouse and stranger hand holding attenuated neural response to the threat, but spousal hand-holding was particularly efficient. Moreover, even within this sample of married couples with high satisfaction levels, the benefits of spousal hand holding under threat were even more important in those couples who have reported the highest quality of marital relationship.
As it was mentioned before, social contact can help regulate emotional responses to cope with life stressors. People who benefit from high social support tend to perceive the stressful situation as less threatening. Consequently, they produce a less intense behavioral response to deal with the stressors. People who have more social support must engage less cognitive effort to regulate emotions than people who do not experience this kind of social support. Relationships provide social support that allows us to engage fewer resources to regulate our emotions, especially when we must cope with stressful situations.
Social relationships have short-term and long-term effects on health, both mental and physical. In a lifespan perspective, recent research suggests that early life experiences still have consequences on health behavior in adulthood. Indeed, either positive or negative effects of relationships tend to foster cumulative advantage or disadvantage in health. Low-quality relationships, as well as the lack of social support, have negative consequences on health, moreover, these consequences can be cumulative in a lifespan perspective.
In some studies, marriage was found as one of the most important relationships for many adults and may have beneficial effects on health, depending on the perception of the marital relationship. Low-quality marital relationships can have negative effects on physical health. Thus, unfortunate marriages might be more associated with morbidity and mortality. Moreover, some physiological responses such as elevations in heart rate, changes in hormone levels related to stress, and alterations to immunity function, emerge during conflict discussions in married couples. Low-quality marital relationships increase the probability of developing chronic stress and tend to have long-term implications for health.
However, the lack of relationships, that is social isolation, loneliness, or social exclusion, have also negative consequences on both mental and physical health. First, it is important to distinguish between two similar expressions that are social isolation and loneliness. Social isolation refers to the objective lack of relationships, whereas loneliness is a more subjective feeling of isolation and distress. A study was conducted in the United States among older adults to examine the relationship between social isolation, loneliness, and health outcomes. The results gave evidence that the feeling of loneliness is not always correlated with social isolation. Indeed, the feeling of loneliness is more strongly related to having mental health problems than objective social isolation.
Younger people are also affected by social isolation. Hefner and Eisenberg conducted a study among college students to evaluate the relationship between social support and mental health. The study reveals two interesting results. First, students with greater risk of social isolation are those who have characteristics that differ from most of their classmates (i.e., minority race or ethnicity, international status, low socio-economic status, etc.). Second, students who report lower quality of social support tend to experience more mental health problems (i.e., depression symptoms) than those who report a higher quality of social support.
Proposed neuroscientific explanations for the link between relationships and health
The development of some research methods such as neuroimaging, hormone studies, and clinical neuropsychology has opened and expanded both the study and the understanding of the link between health and social relationships. Even animal studies have also helped the progress of this new field which is called "neuroscience of health". From a neuroscientific perspective, it could be considered that social experiences involve specific neural systems. Some research has managed to differentiate two brain response systems based on the type of social experience. In this sense, social experiences considered negative would activate brain structures destined to the threat process, and the social experiences perceived as positive or pleasant would involve structures corresponding to the reward system.
Each system, whether it is the threat response system or the reward system, would trigger a series of certain psychophysiological responses that are linked to health such as adaptive behaviors, heart rate, hormone production, blood pressure, respiratory rate, etc. Similarly, it has been argued that the involvement of the reward system would have an inhibitory effect on the alarm system. Some empirical evidence supporting these ideas has been obtained based on research in animals, in humans through neuroimaging, and hormonal studies.
Concerning the threat response system, it has been observed that the dorsal anterior cingulate cortex (dACC), the anterior insula, and the periaqueductal gray play an important role. When these areas have been impaired in animals, they show a reduction of distress. In the same vein, when humans are presented with photos of deceased loved ones, these same structures show a significant activation.
On the other hand, for the reward system linked to the social experience, the ventromedial prefrontal cortex (VMPFC) seems to have an important implication. In a study conducted by Eisenberger and colleagues in 2011, the participants saw a picture of a highly supportive, romantic relationship partner during an experience of physical pain. The results showed increased activation of the VMPFC and at the same time, a decrease of the dACC. Similarly, the supportive messages during social exclusion show the same activity in the VMPFC.
Finally, regarding hormonal studies, Uchino and colleagues suggest that there is a link between the hypothalamic-pituitary-adrenal axis and inflammatory markers that may predict some health problems such as cardiovascular disease, diabetes, and frailty. Furthermore, during social stimuli such as touch or massage, some production of oxytocin has been observed. This hormone has anti-stress effects which are associated with a decrease in cortisol levels and blood pleasure. Thus, although the neuroscientific approach is still in development, there is some neurological evidence of the link between social relationships and health.
Applications
Based on what has been described above, it is important to elaborate interventions that improve physical and mental health by enhancing social relationships. These interventions could target different contexts (work, friendship, etc.) or different populations (young or aged people, married or single, etc.). Identifying the context and the population targeted is important because some individuals are more at risk than others overall or in some specific contexts. For instance, it is well described that students are a population categorized at risk of health problems, and among students, black students are more concerned by mental health problems. In this example, it is important to design an intervention that is specific for black students, which is slightly different from the one designed for students in general.
According to Kawachi and Berkman, some interventions have been proposed, with some success, to improve social ties: support group interventions, one-to-one support interventions, and interventions to enhance natural networks. Due to the variability of each intervention, even in the same category of intervention, that has been proposed in the literature, it is not feasible to draw generalized conclusions. However, by targeting specific contexts and specific populations, some studies found that these kinds of interventions can be effective to improve physical or mental health. For instance, Leung, Orrell, and Orgeta (2015) reviewed the literature testing the positive effect of social support group interventions for people diagnosed with dementia and found out they have small benefits on depression and the quality of life of the patients. However, the trials included in this review are too limited (only two studies that fit the inclusion criteria), they are heterogeneous, meaning that it is difficult to conclude on the effect of social support group interventions on this context, and more randomized controlled trials will be needed.
Four interventions have been identified by Masi and collaborators to reduce loneliness: improving social skills, enhancing social support, increasing opportunities for social interaction, and addressing abnormal social cognition. Increasing opportunities for social interaction and enhancing social skills could have a bigger impact on social isolation, whereas improving social skills and addressing abnormal social cognition focus on loneliness. Improving social skills refers to giving methods to better interact with others. Among lonely college students, this kind of intervention was positively associated with less loneliness. The goal of the interventions that address abnormal social cognition is that lonely individuals learn that automatic negative thoughts are not facts, but hypotheses. For seniors, interventions could be home-visit or telephone contacts, group interventions/activities, etc. The most effective ones might be group interventions. One intervention that aims to increase opportunities for social interaction is befriending, which seems to reduce social isolation. The interventions that seem to be the most effective one is interventions that enhance opportunities for social interaction via group activities or group-based interventions. Men tend to be more receptive to those interventions than women, potentially because women tend to be more self-reliant than men. The interventions that enhance social support seem to be the least effective, and interventions that address abnormal social cognition seem to have the biggest impact on loneliness compared to the other interventions.
Another aspect that is important to mention is the social policies. Because the effect of the relationship on health is also preventive, the implementation of social ties policies may be effective to enhance health and well-being in the population. Some health outcomes (obesity, happiness, etc.) may be widely "expanded" through social networks. Social policies should use this natural effect on the interventions. One major issue that policies must face is that the relation between social ties and health vary across social groups, so they need to be careful about how to and whose implement the interventions. To reduce social isolation, policies can enhance the education system to improve social-emotional skills for instance.
To improve both interventions and health policies, future research is still needed to identify the populations that are at high risk of social isolation and to understand what types of interventions or prevention campaigns can be effective on this public health issue.
Criticism of models
The sample size of related studies has generally been low, which impacts statistical robustness of findings.
Another criticism is a lack of representativeness of the samples. Most of the studies were conducted in western societies. As Adams and Glenn point out, personal relationships can have various effects among different countries. Thus, it is possible that studying in most of the populations of western countries will highlight different results than studying low-income countries. This assumption is reinforced by the findings of De Silva and colleagues that suggest the effect of relationships on health might differ depending on the culture. Hence, it will be important to explore this effect with larger samples that fit better with the populations of the countries and to explore this link between different cultures.
When reviewing the link between social support and depression symptoms, Gariépy et al. found out that the measurement of social support was problematic in the literature. Indeed, the tools used to measure social support were heterogeneous between the studies reviewed. The consequence of this heterogeneity is that it cannot be sure that all the studies measure the same thing. Furthermore, they stated that more than half of the studies reviewed used measurement tools that were not statistically valid, meaning that it is unsure whether these tools truly measure social support. Based on their research, it can be easily guessed that this problem is also found in other research that studies the link between social relationships and health. Digging this issue, Dambi and colleagues compared the translation of one of the most used scales to assess perceived social support, the Multidimensional Perceived Social Support Scale (MSPSS), and found out that they were not equally valid. One of the major issues they described is that the different translated scales were not rigorously translated. Hence, it cannot be possible to compare different studies from different countries that used the MSPSS to evaluate the effect of relationships on health, and it can be assumed that this problem can also be found in other international scales.
Given all the critics presented, this field of psychology needs to explore the links between relationships and health by using reliable methods: bigger sample size, representative samples, causality design, and valid measurement tools. The utilization of these reliable methods will be useful to generalize the findings to a broader population and to enhance the statistical power of the studies (what can be summarized as the quality of the studies). It is reassuring to observe the development of new ways of doing science, like crowdsourced science that encourages the use of better methods to enhance the quality of scientific research.
References
Health
Interpersonal relationships | Relationships and health | [
"Biology"
] | 3,804 | [
"Behavior",
"Interpersonal relationships",
"Human behavior"
] |
62,966,735 | https://en.wikipedia.org/wiki/Distributionalism | Distributionalism was a general theory of language and a discovery procedure for establishing elements and structures of language based on observed usage. The purpose of distributionalism was to provide a scientific basis for syntax as independent of meaning. Zellig Harris defined 'distribution' as follows.“The DISTRIBUTION of an element is the total of all environments in which it occurs, i.e. the sum of all the (different) positions (or occurrences) of an element relative to the occurrence of other elements[.]”Based on this idea, an analysis of immediate constituents could be based on observing the environments in which an element, such as a word, appears in corpora. Critics of distributionalism, such as Louis Hjelmslev, pointed out that the analysis of occurrence adds nothing to traditional structure analysis, which is based on the hierarchical, step-by-step categorization of elements. Hjelmslev proposed glossematics, which combines the analysis of meaning and form. However, in American linguistics in the 1960s, distributionalism became replaced by Noam Chomsky's proposal of transformational generative grammar. It proposed that the constituency structure is the manifestation of innate grammar, allowing the preservation of autonomous syntax.
Origins
Distributionalism can be said to have originated in the work of structuralist linguist Leonard Bloomfield and was more clearly formalised by Zellig S. Harris.
This theory emerged in the United States in the 1950s, as a variant of structuralism, which was the mainstream linguistic theory at the time, and dominated American linguistics for some time. Using "distribution" as a technical term for a component of discovery procedure is likely first to have been done by Morris Swadesh in 1934 and then applied to principles of phonematics, to establish which observable various sounds of a language constitute the allophones of a phoneme and which should be kept as separate phonemes.
According to Turenne and Pomerol, distributionalism was in fact a second phase in the history of linguistics, following that of structuralism, as distributionalism was mainly dominant since 1935 to 1960. It is considered one of the scientific grounds of Noam Chomsky's generative grammar and had considerable influence on language teaching.
Distributionalism has much in common with structuralism. However, both appear in the United States while the theses of Ferdinand de Saussure are only just beginning to be known in Europe: distributionism must be considered as an original theory in relation to Saussurianism.
Behaviorist psychological theories which allowed the birth of distributionalism are reminiscent of Pavlov's work on animals. According to these theories, human behaviour would be totally explainable, and its mechanics could be studied. The study of reflexes, for example, should have made it possible to predict certain attitudes. Leonard Bloomfield argues that language, like behaviour, could be analysed as a predictable mechanism, explicable by the external conditions of its appearance.
The notions of "mechanism", "inductive method" and "corpus" are key terms of distributionalism.
Mechanism vs Mentalism
Bloomfield calls his thesis mechanism, and he opposes it to mentalism: for him, in fact, speech cannot be explained as an effect of thoughts (intentions, beliefs, feelings). Thus, one must be able to account for linguistic behaviour and the hierarchical structure of the messages conveyed without any assumptions about the speakers' intentions and mental states.
From the behaviourist perspective, a given stimulus corresponds to a given response. However, meaning is an unstable thing for distributionists, depending on the situation, and is not observable. It must therefore be eliminated as an element of language analysis. The only regularity is of a morphosyntactic nature: it is the structural invariants of the morphosyntax that allow us to reconstruct the language system from an analysis of its observable elements, the words of a given corpus.
Salient features
The main idea of distributionalism is that linguistic units "are what they do", which means that the identity of linguistic units are defined by their distribution. Zellig Harris used to consider meaning as too intuitive to be a reliable ground for linguistic research. Language use has to be observed directly while looking at all the environments in which a unit can occur. Harris advocated for a distributional approach, since "difference of meaning correlates with difference of distribution.".
References
Sources
Matthews, P. H.. 1993. Grammatical Theory in the United States from Bloomfield to Chomsky. Cambridge Studies in Linguistics: 67,
John G. FOUGHT, Diamond BAR, "Distributionalism and Immediate Constituent Analysis in American Linguistics", in Auroux, Sylvain / Koerner, E.F.K. / Niederehe, Hans-Josef / Versteegh, Kees, Eds. 2001, History of the Language Sciences, vol. 2, coll. Handbücher zur Sprach- und Kommunikationswissenschaft / Handbooks of Linguistics and Communication Science (HSK) 18/2, DE GRUYTER MOUTON, 1986–97.
Geeraerts, Dirk. 2017. "Distributionalism, old and new", in Makarova, Anastasia, Dickey, Stephen M., Divjak, Dagmar Eds., Each Venture a New Beginning. Studies in Honor of Laura A. Janda, Slavica Publisher; Bloomington, IN, , pp. 29 – 38
Theories of language
Computational linguistics | Distributionalism | [
"Technology"
] | 1,139 | [
"Natural language and computing",
"Computational linguistics"
] |
62,966,941 | https://en.wikipedia.org/wiki/Sleep%20emailing | Sleep messaging (or sleep emailing or sleep texting) is a phenomenon related to sleepwalking where people send emails or other textual communications to co-workers in a combined state of sleep and wakefulness.
References
Parasomnias
Sleep disorders | Sleep emailing | [
"Biology"
] | 51 | [
"Behavior",
"Sleep",
"Sleep disorders"
] |
62,967,629 | https://en.wikipedia.org/wiki/Dingwall%20Beloe%20Lecture%20Series | The Dingwall Beloe Lecture Series is the result of bequests by Eric Dingwall, formerly an Assistant Keeper of Printed Books in the British Museum, and to the Clockmakers Company by Reginald Beloe TD, the noted horological collector and Master of the Company in 1977.
History
The Museum and the Company agreed the formation of a fund to back the presentation of an annual lecture, intended to make new contributions to the history of horology, with a particular international focus.
The lectures, under the organization of the Clocks and Watches department of the British Museum, have become one of the most significant annual events in the international horological calendar. The inaugural lecture was in 1989.
The lectures
1989 Giuseppe Brusa, Museo Poldi Pezzoli, Milan, 'Early mechanical horology in Italy'
1990 Joachim Schardin, Staatlich Mathematisch-Physikalischer Salon, Dresden, 'The history of the horological collections in Dresden'.
1991 Anthony Turner, 'Berthoud in England, Harrison in France: the transmission of horological knowledge in 18th century Europe'.
1992 Jan Jaap Haspels, Director/Curator, Museum Speelklok, Utrecht, 'The Early History of Musical Clocks'.
1993 owing to the illness of K. J. Langer, Munich, who was to lecture on 'German Precision Horology After 1800', David Thompson of the British Museum gave a talk on 'The British Museum Horological Collections'.
1994 Gerhard Dohrn-van Rossum, Chemnitz University of Technology, 'Public Clocks and Modern Hours - Time Measurement and Urban Life since the late Middle Ages'.
1995 John Leopold, British Museum, 'The Third Seafaring Nation: The introduction of the marine chronometer in the Netherlands'.
1996 Jaroslav Folta, National Technical Museum (Prague), 'Horology in Prague'.
1997 Peter Friess, Deutsches Museum Bonn, 'An unknown talent of German clockmaking: Joseph Weidenheimer 1758– 1795'.
1998 Günther Oestmann, University of Hamburg, 'The Strasbourg Cathedral Clock'.
1999 James Dowling, London, 'Mechanical Timekeeping in the Electronic Age'.
2000 William J. H. Andrewes, Concord, Massachusetts 'French Clocks in American Collections'.
2001 Mikhail Gouriev, Hermitage Museum, St. Petersburg, 'Clocks and Watches in the Hermitage'.
2002 Jonathan Betts, National Maritime Museum, 'John Hyacinth Magellan (1720– 1790), horological and scientific agent'.
2003 Sir George White, Worshipful Company of Clockmakers, Jeremy Evans, The British Museum, 'Thomas Tompion 'at The Dial and Three Crowns' '.
2004 David Penney, 'Evidence from the Transient: The Importance of Ephemera for a Proper Understanding of the Clock and Watch Making Trade'.
2005 Professor Carlos R. Alba, Autonomous University of Madrid (collector) & Juan J. Ontalva (clockmaker), 'Spain's Magnificent Horological Collections: An English and French Heritage'.
2006 Roger Smith, 'The Sing-SongTrade: Exporting Clocks to China in the Eighteenth Century'.
2007 Hans Boeckh, Patek-Philippe Museum, Geneva, 'French Literary Themes on 17th-Century Watches'.
2008 Paul Buck, British Museum, 'Courtenay Adrian Ilbert (1888–1956), Horological Collector'.
2009 John Glanville, 'Made in England – House clock production in the 20th century'.
2010 Eddy Fraiture and Paul van Rompay (Belgian Horological Society), 'Clock & Watch Making in Flanders 1300–1830'.
2011 Michael Grange, Cheltenham, 'The Grange Collection at the British Museum. English Provincial Clockmaking 1695–1840. The Role of the Thirty-Hour Clock'.
2012 Alice Arnold-Becker, 'Friedberg – a centre of watch and clock making in 17th and 18th century Bavaria'.
2013 Eduard C. Saluz, Deutsches Uhrenmuseum, 'The German Clock Museum Furtwangen – 160 Years of collecting'.
2014 Andrew King, 'Winner or loser. Did John Harrison win the Longitude Prize?'
2015 James Nye, Chairman AHS, An Englishman, a Frenchman, and a Watchman—The Cross-Border Life of Robert Lenoir (1898–1979) (available on YouTube)
2016 Sibylle Gluch, 'Timing the stars: astronomers, clockmakers and German precision horology around 1800'
2017 Matthew Champion, 'The music of the clock, c.1300–c.1600'
2018 Marisa Addomine, 'Heavenly advisors: the astrological purpose of public clocks in Italy'
2019 Sebastian Whitestone, 'Revelation in revision. How alterations to a woodcut block change the history of Huygens' pendulum clock invention'
2020 Owing to COVID-19 restrictions, the lecture was combined with the annual Harrison Lecture of the Clockmakers Company and held virtually as a Zoom webinar, entitled 'Time in a Space'. There were three speakers: Joanna Migdal, 'Proportion - An Artist Craftsman's Perspective'; John Martineau, 'The Beauty of Asymmetry'; and Lee Yuen-Rapati, 'The Importance of Spacing in Clock and Watch Dial Design'. (available on YouTube)
2022 Peter de Clercq, 'Travel journals and the history of horology'.
2023 Keith Scobie-Youngs, 'From Man to Machine - The history of the winding of the Great Clock of Westminster'.
2024 Michael Korey, 'Geared to the planets'.
References
If there are references to two locations in Antiquarian Horology, the first gives the location of the announcement of the lecture, the second the location of the published text.
British Museum
British lecture series
Horology
1989 establishments in the United Kingdom
Recurring events established in 1989 | Dingwall Beloe Lecture Series | [
"Physics"
] | 1,220 | [
"Spacetime",
"Horology",
"Physical quantities",
"Time"
] |
62,968,102 | https://en.wikipedia.org/wiki/Ding%20%28company%29 | Ding is an international mobile recharge service, allowing users to send mobile top-up to friends and family in over 150 countries and across more than 500 global operators.
History
The company was founded by Mark Roden on June 23, 2006. In October 2019 the company opened a new office in London. In 2016, Ding acquired French retail top-up company called Transfert Credit.
In 2018 Ding released its DingConnect API, allowing businesses to integrate the Ding platform to sell or offer mobile top-up on their website or mobile app. In 2018, the company was listed by the Financial Times as one of Europe's fastest growing companies. In January 2019, Ding agreed a partnership with Logista that will see it provide international top-up services at over 10,000 Spanish outlets. On May 19, 2019, Ding announced its partnership with LuLu Money to offer international mobile top-up to foreign workers living in the Asia Pacific region.
As of 2022, its users have sent over 500 million mobile top-ups online, on the Ding app and across 600,000 retail outlets worldwide.
References
External links
Mobile telecommunication services
Technology companies of the Republic of Ireland | Ding (company) | [
"Technology"
] | 236 | [
"Mobile telecommunications",
"Mobile telecommunication services"
] |
62,968,403 | https://en.wikipedia.org/wiki/Cognitive%20ecology%20of%20individual%20recognition%20in%20colonial%20birds | The cognitive ecology of individual recognition has been studied in many species, especially in primates or other mammalian species that exhibit complex social behaviours, but comparatively little research has been done on colonial birds. Colonial birds live in dense colonies in which many individuals interact with each other daily. For colonial birds, being able to identify and recognize individuals can be a crucial skill.
Sociality and brain size
Individual recognition is one of the most basic forms of social cognition. If we were to define individual recognition, it would imply that a given individual has the capacity to discriminate a familiar individual from another one at any given time. It is believed that in many species, group size is often a representation of social complexity, with higher social complexity demanding higher cognitive capabilities. This hypothesis is also known as the "social brain hypothesis" and has been supported by many researchers. The logic behind this hypothesis is based on the principle that larger group size will require a higher degree of complexity in their interactions. Many studies have looked at the effect of sociality on the brain development, mostly focussing on non-human primate species. In primates, it has been shown that relative brain size, when controlling for the size of the species and the phylogeny, seemed to correlate with the size of the social group. These results allowed for a direct correlation between sociality and cognition. However, when reproducing such experiments in non-primate species, like with reptiles, birds and even other mammalian species, the correlation between brain size and social group size does not seems to exist. A study done on mountain chickadees looking at the impact of sociality on the hippocampus size as well as on neurogenesis found no evidence of change related to group size, therefore rejecting the "social brain hypothesis" in birds. Further research looking at bird cognitive ecology demonstrated that social complexity is a more reliable proxy for brain size, as it relies not only on the number of individuals but also on the degree of social interactions and more.
Role of recognition
In the wild, recognition can have many advantages. When looking at monogamous birds species, being able to recognize your mate can be crucial. As colonial birds tend to cluster in high density groups, finding your mate can be a challenge. Being able to identify your mate is not all, recognition can also help in the context of mate selection as individual recognition allows birds to avoid inbreeding with conspecifics. Inbreeding avoidance has been shown in a species of storm petrel, a colonial seabird that nests in burrows. In the case of storm petrels, individual relatedness is assessed based on olfactory signatures that allow them to distinguish closely related individuals from non-related ones. The capacity of an individual to identify conspecifics is not only used to avoid inbreeding, but can also be used in order to help closely related individuals. Such instances can be seen in scrub jays, whose offspring stay after fledging in order to help raise the next brood.
Moreover, recognition can be useful for chick identification. Being able to recognize your own chick is essential in many colonial bird species as chicks can wander around and mix up with others' chicks. Feeding the wrong chick would result in high cost for the parent with little to no benefit for their own reproductive success. In herring gulls, chicks can be found wandering around the colony only a few days after hatching from the egg, creating a need for the parent to recognize its own chick. However, in order to have evolved, recognition needs to be beneficial not only for one side, but for both sides, meaning that the chick has to be able to recognize its parents as well. Still looking at herring gulls, chicks will often hide when the parents are not present in order to avoid being predated on by other adult herring gulls or any other predator. Therefore, being able to recognize your parent is crucial in order to reveal your position to the right adult. In the case of bird species that raise many offspring at once, chicks that are able to recognize their parents may also increase their begging rate and therefore obtain more food in return. Chicks that have better recognition capacities would therefore have the advantage over their siblings.
Mechanism of recognition in colonial birds
Olfactory recognition
It has been believed for a long time that birds had a very bad sense of smell, but recent studies have demonstrated that some species of birds such as the procellariiformes have a quite developed sense of smell. Olfaction seems to be used in an array of different task such as for finding food, migrating and kin recognition. In burrowing species such as in puffins, auks and petrels, smells seem to be at the basis of mate and nest recognition. The procellariiformes, also known as tubed-noses, are one of the best studied groups when it comes to olfaction as they seem to have a quite developed sense of smell. A study done on storm petrels showed that not only do petrels use olfaction in order to find their burrow and their mate, but that they are also aware of their own smell. Petrels nest in dense colonies and use the smell of their mate or their own smell in order to find their burrow and avoid entering the wrong burrow. Such a mechanism of recognition has also been shown in auks as they mostly fly at night, keeping them from using spatial memory in order to find their burrow. When looking at the available literature, olfactory cues seems to be used mostly by colonial birds that nest in burrows.
Concerning chick recognition in burrowing birds, a researcher called Eduardo Minguez (1997) showed that there was no chick recognition in storm petrels. One of the advantages of burrow nesting is that your chick is confined in the burrow until it is ready to fledge, eliminating the need for chick recognition. It is likely that chicks will acquire their "signature smell" only later upon fledging the parental nest. There are few instances of burrowing birds that have the mechanism of chick recognition, but as recognition is a costly mechanism, it tends to be lost in many bird species for which it is not necessary.
Acoustic recognition
In many bird colonies, the environment in the colony tends to be quite loud and filed with countless acoustic stimuli. Many researchers have looked into how individuals can identify each other in such a heavily charged acoustic environment. Recognition based on acoustic signatures has been demonstrated in many bird species such as in penguins, swallows, gulls, razorbills and more. A study done on king penguins by Jouventin et al. (1999) was one of the first study to look at the technicalities behind acoustic recognition. They found that chicks could identify their parents based on an acoustic signature specific to the pattern of the call as well as the frequency of the parents' call. The amplitude of the call did not seem to affect the call signature. A similar study done on black-headed gulls in 2001 obtained similar results supporting that the acoustic signatures of parents' calls is most likely based on a redundant pattern and the frequency of the call with no effect regarding the amplitude. This study also supported that the mechanism of acoustic recognition is most likely the same in most species within the gull family, Laridae. Nevertheless, not all members of Laridae exhibit parent-offspring recognition.
The black-legged kittiwake, a small cliff nesting gull, does not seem to recognize its chick. This lack of recognition is most likely the result of cliff nesting, as chicks cannot explore far from the nest and get mixed with other chicks. Recognition would have then been lost in kittiwakes. Other exceptions can be found, for example in razorbills. Razorbills exhibit parent-offspring recognition, but research has shown that only males and chicks exhibit such behaviour, meaning that females do not recognize their chick and vice versa. Such difference between the parents can be explained when looking at the natural history of razorbills. Like in kittiwakes, razorbills are cliff nesters, limiting the chicks movement quite a bit. However, when the chick will fledge, only the male will bring the chick out at sea and will keep caring for its chicks for a little while after fledging, creating the need to be able to recognize its own chick. As females do not follow its offspring at sea, there is no need for her to recognize her own chick.
References
Animal cognition | Cognitive ecology of individual recognition in colonial birds | [
"Biology"
] | 1,720 | [
"Animals",
"Animal cognition"
] |
62,971,153 | https://en.wikipedia.org/wiki/Nuclear%20anxiety | Nuclear anxiety, also known as nucleomitophobia, refers to anxiety or even a phobia in the face of a potential future nuclear holocaust, particularly during the Cold War and more recently the Russian invasion of Ukraine.
American anthropologist Margaret Mead viewed such anxiety in the 1960s as a violent survivalist impulse that should instead be channeled toward a recognition of the need for peace. American psychologist Michael D. Newcomb and others defined "nuclear anxiety" in the 1980s post-détente period, Newcomb developing a psychometric to evaluate it with the Nuclear Attitudes Questionnaire (NAQ) in 1986, although mental effects had been at issue since the start of the Atomic Age.
The term originates from the Cold War period and has been defined as a "fear of nuclear war and of its consequences". It was particularly examined as an issue in child and adolescent psychiatry and much of the research on nuclear anxiety among youth was conducted in the 1980s in many countries. Due to the influence of the particular context under which studies were carried out, replicability is difficult if not impossible to verify. More recent studies regarding nuclear anxiety in the 21st century are relatively scarce.
Causes
Historical context
The buildup of fear regarding the plausibility of nuclear threat was embedded in the historical and political context of the Cold War. Political events such as the use of nuclear bombs on Hiroshima and Nagasaki in 1945 had proven the destructive power of nuclear weapons, while the Cuban Missile Crisis and Euromissile Crisis contributed to broadcasting to the wider public the increase of tensions between superpowers, and warned of the increasing possibility of resorting to nuclear missiles. Fear of mutually assured destruction stoked nuclear anxiety.
Nuclear anxiety took a greater importance in the political landscape of the United States around the 1984 presidential elections. Two adolescents spoke to Congress of their fears of nuclear war in an event hosted by the United States House Select Committee on Children, Youth and Families on 20 September 1983. The American Orthopsychiatric Association led programmes around nuclear anxiety in children. In addition, Walter Mondale mentioned “nuclear nightmares” experienced by American youth in a speech given during his 1984 election campaign.
Dispute
The existence of nuclear anxiety experienced by youth in the United States in the Cold War has been challenged by Joseph Adelson and Chester E. Finn Jr. in their 1985 article Terrorizing Children. They denounce the political left of spreading fear among children for political ends. The authors argue that nuclear anxiety was not prevalent in children before the term was coined, and that surveys measuring nuclear anxiety regularly confronted youth with the thought of nuclear weapons to distill fear.
Adelson and Finn's Terrorizing Children caused controversy and was considered unscientific, as the author's criticism of the American Psychological Association's nuclear anxiety-related programmes, called it a “fifty-ring circus” led by “luminaries of the Left”, and questioned the credibility of researchers and journals that published evidence of nuclear anxiety among children.
It has also been argued that wealth, ethnicity and social class have a role in the cause of nuclear anxiety. This claim asserts that wealthy, white children of upper class are more susceptible to suffer from nuclear anxiety as they are exposed to fewer discriminatory or material concerns than children of colour and of lower social class.
Both arguments regarding fear-mongering and social conditioning were debated by other researchers who found no correlation between nuclear anxiety, political preferences and social class.
Prevalence during the Cold War
Nuclear anxiety was prevalent in many parts of the world during the 1980s. Nuclear threats were identified among northern European students as their biggest concern, as the second or third biggest concern among North American students in 1986, and was a source of anxiety in Third World countries, such as among Colombian youth. It was rated the most frequently mentioned concern among Ontario students in 1985 and Finnish children and teenagers in a national survey in the same year.
Newcomb's Nuclear Attitudes Questionnaire
Michael D. Newcomb created a Nuclear Attitudes Questionnaire for a study with the aim of assessing 722 young adults’ opinions and fears of nuclear power plants and weapons. The fifteen-item questionnaire uses likert-scale questions to evaluate four constructs: nuclear concern, nuclear support, fear of the future and nuclear denial. Possible responses to each item were “Strongly disagree or disagree”, “Don't know”, and “Agree or strongly agree”.
Impact on mental health
Nuclear anxiety has been found to have negative effects on mental health on people of all ages, and especially on children and teenagers, and have been found in many countries throughout the world due to the omnipresence of nuclear threats. These impacts typically include feelings of anxiety, helplessness, frequent worrying, stress, hopelessness, loss of meaning or purpose, fear, low life satisfaction, depression, increased drug use, “disturbances in maturational development” among youth, worthlessness, loneliness, alienation, low self-esteem and low subjective wellbeing. Nuclear anxiety also correlated among teenagers with getting into trouble.
Some gender differences have been found with regards to these effects. A study has found that men were less inclined to report anxiety and more inclined to deny the threats of nuclear warfare than women, potentially due to machismo according to the author. Women also reported lower life satisfaction and men higher drug use.
Impacts on mental health also depend on the extent of worry about nuclear threats. While worry to the level of “concern” rarely leads to degradation of mental health, while worry to the level of “despair” has been found to have impacts on mental health that remain stable over time, but that subjects can live with.
Parental denial of the existence of a nuclear threat or of nuclear anxiety worsens its consequences.
Effects on mental health also depended on whether subjects participated in disarmament activism. Those who did not faced bigger anxiety-related issues lasting until at least mid-adulthood, while those who did reported no decrease in mental health.
Impact on activism
Nuclear anxiety has also had an impact on political activism, notably through peace protests and the nuclear freeze movement. Nuclear anxiety has been correlated with greater opposition to nuclear armament and with the desire to take action about the issue. Those who believe that survival is unlikely or impossible in the advent of a nuclear war are likely to turn to antinuclear activism, seeking to educate others about such threats and protesting to pressure governments to disarm. A greater interest in political processes is likely for those whose nuclear anxiety does not surpass the level of ‘concern’, while despaired individuals may be more likely to support disarmament but withdraw from politics due to distrust towards governments and anti-nationalistic feelings.
Protests such as the nuclear freeze movement have also been shown to likely incite support for disarmament among those experiencing nuclear anxiety.
Treatment
Treatment of nuclear anxiety mainly revolves around finding a way to live with fear and taking action to limit its nefarious effects on mental health. Preparing food and medical supplies to enhance chances of survival has been correlated with increased optimism, key to reducing anxiety. Discussing fears with peers, family and teachers has also been useful to alleviate anxiety and increase confidence. Activism may be very efficient at reducing nuclear anxiety, as it helps minimise feelings of helplessness and empowers subjects. Mobilisation can greatly reduce adverse effects of nuclear anxiety.
The participation of relatives, especially parents, in disarmament activism has been linked to higher participation of subjects and higher optimism.
Some nuclear anxiety workshops have found success at reducing nuclear anxiety and finding a meaning to life in the nuclear age, especially those practising logotherapy.
One study compiled coping mechanisms used to treat nuclear anxiety as follows:
On the other hand, denial or avoidance of emotional distress and of activism may prevent recovery.
See also
Nuclear holocaust
Nuclear proliferation
Anti-nuclear movement
Anti-nuclear protests
Eco-anxiety
Ecological grief
Psychic numbing
Doomsday Clock
References
Psychological concepts
Mental health
Cold War
Nuclear warfare
Anxiety
Applied psychology | Nuclear anxiety | [
"Chemistry"
] | 1,601 | [
"Radioactivity",
"Nuclear warfare"
] |
62,971,328 | https://en.wikipedia.org/wiki/Sarah%20Trimpin | Sarah Trimpin is a German/American chemist and Professor at the Wayne State University. Her research interests revolve around ionizing methods in mass spectrometry. Her work has resulted in the formation of a company (MSTM, LLC) which aims to bring advanced ionization methods to industry. Her work has been recognized by the American Society for Mass Spectrometry with the Research Award in 2010, and the Biemann Medal in 2019.
Trimpin received her undergraduate training at the Universität Konstanz in Germany in 1999 and her PhD from the Max Planck Institute for Polymer Research in 2002 (Mainz). After postdoctoral work at Oregon State University and Indiana University, she joined the faculty at Wayne State University in 2008.
References
External links
http://www.indiana.edu/~clemmer/home.htm
21st-century American chemists
Mass spectrometrists
Living people
Year of birth missing (living people)
Swiss women chemists
Wayne State University faculty
21st-century German chemists | Sarah Trimpin | [
"Physics",
"Chemistry"
] | 211 | [
"Biochemists",
"Mass spectrometry",
"Spectrum (physical sciences)",
"Mass spectrometrists"
] |
54,426,201 | https://en.wikipedia.org/wiki/Unique%20homomorphic%20extension%20theorem | The unique homomorphic extension theorem is a result in mathematical logic which formalizes the intuition that the truth or falsity of a statement can be deduced from the truth values of its parts.
The lemma
Let A be a non-empty set, X a subset of A, F a set of functions in A, and the inductive closure of X under F.
Let be B any non-empty set and let G be the set of functions on B, such that there is a function in G that maps with each function f of arity n in F the following function in G (G cannot be a bijection).
From this lemma we can now build the concept of unique homomorphic extension.
The theorem
If is a free set generated by X and F, for each function there is a single function such that:
For each function f of arity n > 0, for each
Consequence
The identities seen in (1) e (2) show that is an homomorphism, specifically named the unique homomorphic extension of . To prove the theorem, two requirements must be met: to prove that the extension () exists and is unique (assuring the lack of bijections).
Proof of the theorem
We must define a sequence of functions inductively, satisfying conditions (1) and (2) restricted to . For this, we define , and given then shall have the following graph:
First we must be certain the graph actually has functionality, since is a free set, from the lemma we have when , so we only have to determine the functionality for the left side of the union. Knowing that the elements of G are functions(again, as defined by the lemma), the only instance where and for some is possible is if we have for some and for some generators and in .
Since and are disjoint when this implies and . Being all in , we must have .
Then we have with , displaying functionality.
Before moving further we must make use of a new lemma that determines the rules for partial functions, it may be written as:
(3)Be a sequence of partial functions such that . Then, is a partial function.
Using (3), is a partial function. Since then is total in .
Furthermore, it is clear from the definition of that satisfies (1) and (2). To prove the uniqueness of , or any other function that satisfies (1) and (2), it is enough to use a simple induction that shows and work for , and such is proved the Theorem of the Unique Homomorphic Extension.
Example of a particular case
We can use the theorem of unique homomorphic extension for calculating numeric expressions over whole numbers. First, we must define the following:
where
Be
Be he inductive closure of under and be
Be
Then will be a function that calculates recursively the truth-value of a proposition, and in a way, will be an extension of the function that associates a truth-value to each atomic proposition, such that:
(1)
(2) (Negation)
(AND Operator)
(OR Operator)
(IF-THEN Operator)
References
Theorems in analysis | Unique homomorphic extension theorem | [
"Mathematics"
] | 649 | [
"Theorems in mathematical analysis",
"Mathematical analysis",
"Mathematical problems",
"Mathematical theorems"
] |
54,426,651 | https://en.wikipedia.org/wiki/Ackermann%27s%20formula | In control theory, Ackermann's formula is a control system design method for solving the pole allocation problem for invariant-time systems by Jürgen Ackermann. One of the primary problems in control system design is the creation of controllers that will change the dynamics of a system by changing the eigenvalues of the matrix representing the dynamics of the closed-loop system. This is equivalent to changing the poles of the associated transfer function in the case that there is no cancellation of poles and zeros.
State feedback control
Consider a linear continuous-time invariant system with a state-space representation
where is the state vector, is the input vector, and are matrices of compatible dimensions that represent the dynamics of the system. An input-output description of this system is given by the transfer function
where is the determinant and is the adjugate.
Since the denominator of the right equation is given by the characteristic polynomial of , the poles of are eigenvalues of (note that the converse is not necessarily true, since there may be cancellations between terms of the numerator and the denominator). If the system is unstable, or has a slow response or any other characteristic that does not specify the design criteria, it could be advantageous to make changes to it. The matrices , however, may represent physical parameters of a system that cannot be altered. Thus, one approach to this problem might be to create a feedback loop with a gain that will feed the state variable into the input .
If the system is controllable, there is always an input such that any state can be transferred to any other state . With that in mind, a feedback loop can be added to the system with the control input , such that the new dynamics of the system will be
In this new realization, the poles will be dependent on the characteristic polynomial of , that is
Ackermann's formula
Computing the characteristic polynomial and choosing a suitable feedback matrix can be a challenging task, especially in larger systems. One way to make computations easier is through Ackermann's formula. For simplicity's sake, consider a single input vector with no reference parameter , such as
where is a feedback vector of compatible dimensions. Ackermann's formula states that the design process can be simplified by only computing the following equation:
in which is the desired characteristic polynomial evaluated at matrix , and is the controllability matrix of the system.
Proof
This proof is based on Encyclopedia of Life Support Systems entry on Pole Placement Control. Assume that the system is controllable. The characteristic polynomial of is given by
Calculating the powers of results in
Replacing the previous equations into yields
Rewriting the above equation as a matrix product and omitting terms that does not appear isolated yields
From the Cayley–Hamilton theorem, , thus
Note that is the controllability matrix of the system. Since the system is controllable, is invertible. Thus,
To find , both sides can be multiplied by the vector giving
Thus,
Example
Consider
We know from the characteristic polynomial of that the system is unstable since
the matrix will only have positive eigenvalues. Thus, to stabilize the system we shall put a feedback gain
From Ackermann's formula, we can find a matrix that will change the system so that its characteristic equation will be equal to a desired polynomial. Suppose we want
Thus, and computing the controllability matrix yields
Also, we have that
Finally, from Ackermann's formula
State observer design
Ackermann's formula can also be used for the design of state observers. Consider the linear discrete-time observed system
with observer gain . Then Ackermann's formula for the design of state observers is noted as
with observability matrix . Here it is important to note, that the observability matrix and the system matrix are transposed: and .
Ackermann's formula can also be applied on continuous-time observed systems.
See also
Full state feedback
References
External links
Chapter about Ackermann's Formula on Wikibook of Control Systems and Control Engineering
Engineering concepts
Control engineering
Control theory | Ackermann's formula | [
"Mathematics",
"Engineering"
] | 832 | [
"Applied mathematics",
"Control theory",
"Control engineering",
"nan",
"Dynamical systems"
] |
54,427,200 | https://en.wikipedia.org/wiki/Body%20contact%20%28electricity%29 | A body contact or body fault is a conductive connection between body and active parts of electrical equipment resulting from a fault.
A body, short or ground fault is:
Perfect (direct) contact
If there is no fault resistance in the circuit
Imperfect (indirect) contact
If a fault resistance is present in the circuit (e.g. wet branch, arc)
This can be caused by installation errors or defects, such as cable breaks.
There is a risk of electric shock when touching the parts of the system under voltage by the body joint. As a countermeasure, so-called protective conductors and residual current circuit breakers are used in electrical engineering.
See also
Power engineering
Electrical fault
References
Power engineering | Body contact (electricity) | [
"Engineering"
] | 141 | [
"Power engineering",
"Electrical engineering",
"Energy engineering"
] |
54,427,340 | https://en.wikipedia.org/wiki/Scale%20microfossils | Apatitic scale microfossils are a group of reticulate phosphatic plates found in the Neoproterozoic () strata of the Fifteenmile Group, Yukon, Canada. They represent some of the earliest examples of biologically induced biomineralization, using the mineral hydroxyapatite.
References
Microfossils
Neoproterozoic Canada | Scale microfossils | [
"Chemistry"
] | 79 | [
"Microfossils",
"Microscopy"
] |
54,427,559 | https://en.wikipedia.org/wiki/VoIP%20vulnerabilities | VoIP vulnerabilities are weaknesses in the VoIP protocol or its implementations that expose users to privacy violations and other problems. VoIP is a group of technologies that enable voice calls online. VoIP contains similar vulnerabilities to those of other internet use.
Risks are not usually mentioned to potential customers. VoIP provides no specific protections against fraud and illicit practices.
Vulnerabilities
Eavesdropping
Unencrypted connections are vulnerable to security breaches. Hackers/trackers can eavesdrop on conversations and extract valuable data.
Network attacks
Attacks on the user network or internet provider can disrupt or destroy the connection. Since VoIP requires an internet connection, direct attacks on the internet connection, or provider, can be effective. Such attacks target office telephony. Mobile applications that do not rely on an internet connection to make calls are immune to such attacks.
Default security settings
VoIP phones are smart devices that need to be configured. In some cases, Chinese manufacturers are using default passwords that lead to vulnerabilities.
VOIP over Wi-Fi
While VoIP is relatively secure, it still needs a source of internet, which is often a Wi-Fi network, making VoIP subject to Wi-Fi vulnerabilities
Packet loss
Since VoIP runs over an internet connection, via wired, Wi-Fi or 4G, it is susceptible to packet loss which affects the ability to make and receive calls or makes the calls hard to hear. The susceptibility is due to the real time nature of the communication. Packet loss is the biggest reason for VoIP support calls.
SIP ALG
When VoIP was first setup, a setting called SIP ALG was added to routers to prevent VoIP Packets being modified. However, on more modern VoIP systems, the SIP ALG router setting causes routing issues with VoIP Packets causing calls to drop. Routers are usually shipped with SIP ALG turned on.
Exploits
Spam
VoIP is subject to spam called SPIT (Spam over Internet Telephony). Using the extensions provided by VoIP PBX capabilities, the spammer can harass their target from different numbers. The process can be automated and can fill the target's voice mail with notifications. The spammer can make calls often enough to block the target from getting important calls.
Phishing
VoIP users can change their Caller ID if they have admin rights on the VoIP server. Anyone who resells VoIP or manages their own VoIP server can allocate any phone number as an outgoing number. This is commonly used for genuinue reasons when a customer is porting a number, so they can use their number of a new plaform while the port takes place. But it can be used maliciously to mask any number. (a.k.a. Caller ID spoofing), allowing a caller to pose as a relative or colleague in order to extract information, money or benefits from the target.
See also
Comparison of VoIP software
INVITE of Death
List of VoIP companies
Mobile communications over IP - Mobile VoIP
Voice over WLAN - VoIP over a WiFi network
References
Internet security | VoIP vulnerabilities | [
"Technology"
] | 650 | [
"Computer security exploits"
] |
54,427,567 | https://en.wikipedia.org/wiki/NGC%203506 | NGC 3506 is a spiral galaxy in the constellation Leo. It is located at a distance of circa 300 million light years from Earth, which, given its apparent dimensions, means that NGC 3506 is about 115,000 light years across. The galaxy has two main spiral arms, with high surface brightness, which can be traced for half a revolution before they fade. One arm splits into four spiral arcs.
Three supernovae have been observed in NGC 3506: SN 2003L (type Ic, mag. 16.9), SN 2017dfq (type Ia, mag. 15.3), and SN 2021adgz (type II, mag. 19.4). SN 2003L spectrum featured a relatively blue continuum, dominated by strong P-Cyg lines of Ca II (H and K) and Fe II and a relatively weaker Si II 635.5-nm line was also visible.
It is an isolated galaxy.
Gallery
See also
UGC 6093 - A nearby barred spiral galaxy
References
External links
Spiral galaxies
Leo (constellation)
3506
06120
33379 | NGC 3506 | [
"Astronomy"
] | 228 | [
"Leo (constellation)",
"Constellations"
] |
54,428,435 | https://en.wikipedia.org/wiki/NGC%20596 | NGC 596 is an elliptical galaxy in the constellation Cetus. The galaxy lies 65 million light years away from Earth, which means, given its apparent dimensions, that NGC 596 is approximately 60,000 light years across. The galaxy shows an outer envelope and is a merger remnant. The surface brightness profile is smooth and featureless. The galaxy hosts a supermassive black hole, whose mass is estimated to be 170 million (108.24) .
NGC 596 belongs at the NGC 584 galaxy group, which also includes the galaxies NGC 584, which lies 25 minutes to the northwest, NGC 600, NGC 615 and NGC 636.
The galaxy is included in the Herschel 400 Catalogue. It lies about 2 and half degrees northeast from theta Ceti.
References
External links
Elliptical galaxies
Cetus
0596
005766 | NGC 596 | [
"Astronomy"
] | 170 | [
"Cetus",
"Constellations"
] |
54,428,859 | https://en.wikipedia.org/wiki/ICPRAM | The International Conference on Pattern Recognition Applications and Methods (ICPRAM) is held annually since 2012. From the beginning it is held in conjunction with two other conferences: ICAART - International Conference on Agents and Artificial Intelligence and ICORES - International Conference on Operations Research and Enterprise Systems.
ICPRAM is composed by two main topics areas: theory and methods and applications. Each one of these areas is constituted by several sub-topics like Evolutionary Computation, Density Estimation, Spectral method, Combinatorial Optimization, Reinforcement learning, Meta learning, Convex optimization in the case of Theory and methods and Natural language processing, robotics, Signal processing, Information retrieval, perception in the applications area.
The conference papers are made available at the SCITEPRESS digital library and are published in the conference proceedings. It's also made a selection of the best papers presented in the conference for publication in a Springer volume.
Besides the presentation of papers from the authors, the conference is composed by tutorials. For example, the conference had a tutorial on Secure our society - Computer Vision Techniques for Video Surveillance given by Huiyu Zhou from the Queen's University Belfast, UK.
Since the first edition, ICPRAM has counted on several keynote speakers like Tomaso Poggio, Josef Kittler, Hanan Samet, Nello Cristianini, John Shawe-Taylor and Antonio Torralba.
Editions
ICPRAM 2020 - Valletta, Malta
ICPRAM 2019 - Prague, Czech Republic
ICPRAM 2018 - Funchal, Madeira, Portugal
ICPRAM 2017 - Porto, Portugal
ICPRAM 2016 - Rome, Italy
ICPRAM 2015 - Lisbon, Portugal
ICPRAM 2014 - ESEO, Angers, Loire Valley, France
ICPRAM 2013 - Barcelona, Spain
ICPRAM 2012 - Vilamoura, Algarve, Portugal
Best Paper Awards
2019
Area: Applications
Best Paper Award: Yehezkel S. Resheff, Itay Lieder and Tom Hope. "All Together Now! The Benefits of Adaptively Fusing Pre-trained Deep Representations"
Area: Applications
Best Student Paper Award: Manex Serras, María Inés Torres and Arantza del Pozo. "Goal-conditioned User Modeling for Dialogue Systems using Stochastic Bi-Automata"
2018
Area: Theory and Methods
Best Paper Award: Huanqian Yan, Yonggang Lu and Heng Ma. "Density-based Clustering using Automatic Density Peak Detection"
Area: Applications
Best Student Paper Award: Marcin Kopaczka, Marco Saggiomo, Moritz Guttler, Thomas Gries and Doreit Merhof. "Fully Automatic Faulty Weft Thread Detection using a Camera System and Feature-based Pattern Recognition"
2017
Area: Theory and Methods
Best Paper Award: Seiya Satoh and Ryohei Nakano. "How New Information Criteria WAIC and WBIC Worked for MLP Model Selection"
Best Student Award: Xiaoyi Chen and Régis Lengellé. "Domain Adaptation Transfer Learning by SVM Subject to a Maximum-Mean-Discrepancy-like Constraint"
Area: Applications
Best Paper Award:Sarah Ahmed and Tayyaba Azim. "Compression Techniques for Deep Fisher Vectors"
Best Student Award:Niels Ole Salscheider, Eike Rehder and Martin Lauer. "Analysis of Regionlets for Pedestrian Detection"
2016
Area: Theory and Methods
Best Paper Award: Anne C. van Rossum, Hai Xiang Lin, Johan Dubbeldam and H. Jaap van den Herik. "Nonparametric Bayesian Line Detection - Towards Proper Priors for Robotic Computer Vision "
Best Student Award: Roghayeh Soleymani, Eric Granger and Giorgio Fumera. "Classifier Ensembles with Trajectory Under-Sampling for Face Re-Identification "
Area: Applications
Best Paper Award: Jeonghwan Park, Kang Li and Huiyu Zhou . "k-fold Subsampling based Sequential Backward Feature Elimination "
Best Student Award: Julia Richter, Christian Wiede, Enes Dayangac, Markus Heß and Gangolf Hirtz. "Activity Recognition based on High-Level Reasoning - An Experimental Study Evaluating Proximity to Objects and Pose Information "
2015
Area: Theory and Methods
Best Paper Award: Mohamed-Rafik Bouguelia, Yolande Belaïd and Abdel Belaïd. "Stream-based Active Learning in the Presence of Label Noise"
Best Student Paper: João Costa and Jaime S. Cardoso. "oAdaBoost"
Area: Applications
Best Paper Award: Wei Quan, Bogdan Matuszewski and Lik-Kwan Shark. "3-D Shape Matching for Face Analysis and Recognition"
Best Student Paper: Julia Richter, Christian Wiede and Gangolf Hirtz. "Mobility Assessment of Demented People Using Pose Estimation and Movement Detection"
2014
Area: Theory and Methods
Best Paper Award: Jameson Reed, Mohammad Naeem and Pascal Matsakis. "A First Algorithm to Calculate Force Histograms in the Case of 3D Vector Objects"
Best Student Paper: Johannes Herwig, Timm Linder and Josef Pauli. "Removing Motion Blur using Natural Image Statistics"
Area: Applications
Best Paper Award: Sebastian Kurtek, Chafik Samir and Lemlih Ouchchane. "Statistical Shape Model for Simulation of Realistic Endometrial Tissue"
Best Student Paper: Florian Baumann, Jie Lao, Arne Ehlers and Bodo Rosenhahn. "Motion Binary Patterns for Action Recognition"
2013
Area: Theory and Methods
Best Paper Award: Barbara Hammer, Andrej Gisbrecht and Alexander Schulz. "Applications of Discriminative Dimensionality Reduction"
Best Student Paper: Cristina Garcia-Cardona, Arjuna Flenner and Allon G. Percus. "Multiclass Diffuse Interface Models for Semi-supervised Learning on Graphs"
Area: Applications
Best Paper Award: Yoshito Otake, Carneal Catherine, Blake Lucas, Gaurav Thawait, John Carrino, Brian Corner, Marina Carboni, Barry DeCristofano, Michale Maffeo, Andrew Merkle and Mehran Armand. "Prediction of Organ Geometry from Demographic and Anthropometric Data based on Supervised Learning Approach using Statistical Shape Atlas"
Best Student Paper: James Lotspeich and Mathias Kolsch. "Tracking Subpixel Targets with Critically Sampled Optics"
2012
Area: Theory and Methods
Best Paper Award: Martin Emms and Hector-Hugo Franco-Penya. "ON ORDER EQUIVALENCES BETWEEN DISTANCE AND SIMILARITY MEASURES ON SEQUENCES AND TREES"
Best Student Paper: Anna C. Carli, Mario A. T. Figueiredo, Manuele Bicego and Vittorio Murino. "GENERATIVE EMBEDDINGS BASED ON RICIAN MIXTURES"
Area: Applications
Best Paper Award: Laura Antanas, Martijn van Otterlo, José Oramas, Tinne Tuytelaars and Luc De Raedt. "A RELATIONAL DISTANCE-BASED FRAMEWORK FOR HIERARCHICAL IMAGE UNDERSTANDING"
Best Student Paper: Laura Brandolini and Marco Piastra. "COMPUTING THE REEB GRAPH FOR TRIANGLE MESHES WITH ACTIVE CONTOURS"
References
External links
Science and Technology Events
Conference website
Science and Technology Publications
Event management system
WikiCfp call for papers
Information systems conferences
Computer science conferences
Academic conferences | ICPRAM | [
"Technology"
] | 1,481 | [
"Computer science",
"Computer science conferences"
] |
54,429,225 | https://en.wikipedia.org/wiki/USP-1 | USP-1 or "Tyulpan" (From Russian: Унифицированный Стрелковый Прицел, первый образец, Unifitsirovannyj Strelkovyj Pritsel, pervyj obrazets, "Unified Firearm Sight, first model, GRAU index 1P29) is a Soviet/Russian universal optic sight, used on the AK rifle family (AKMN, AK-74N, AK-74M, AK-101, AK-102, AK-105), the RPK-74N, the PKMN and the PKP "Pecheneg" and is designed for quick-mounting and quick-detaching. Compared with an open mechanical sight, the effectiveness of firing at targets is increased 1.2 to 2 times, and the time taken to conduct a firing session is reduced by 60%. [ It was designed by the Royal Armaments Research Development Establishment (RARDE) in the United Kingdom in the early 1970s; the design was stolen by the USSR, and new elevation cams ballistically matched to Soviet weapons were developed to replace the original British cam matched to the L1A1 Self-Loading Rifle. Production is conducted in Novosibirsk instrument manufacturing factory (NPZ). ] - needs proper historical citation.
Design
The sight possesses a mechanism for adjustments and a stadiametric rangefinder. No batteries are required in the sight. The optic scheme of the sight is a prismatic wrapping. It is easily mounted on the weapon using the standard Warsaw Pact rail. The sight is a copy of the British L2A2 Sight Unit Infantry Trilux.
Specifications
Sight weight: 0.8 kg
Weight of a complete sight system: 1.25 kg
Magnification: 4x
Field of view: 8 (14) degrees
Exit pupil diameter: 6.5 mm
Exit pupil length: 35 mm
Resolution limit: 13 sec
Amount of light retained: >70 %
Adjustment range for zeroing: 0 – 400 m for vertical and horizontal adjustments
Dimensions (L x H x W): 203 mm x 80 mm x 178 mm
Literature (in Russian)
Изделие 1П29. Техническое описание и инструкция по эксплуатации, АЛ3.812.129 ТО. — 1994 г.
Оружие ближнего боя России / Альманах. — М.: НО «Лига содействия оборонным предприятиям», 2010. — 660 с. —
References
Firearm components
Optical devices
Firearm sights of the Soviet Union | USP-1 | [
"Materials_science",
"Technology",
"Engineering"
] | 623 | [
"Glass engineering and science",
"Firearm components",
"Optical devices",
"Components"
] |
54,431,332 | https://en.wikipedia.org/wiki/Mariya%20Zerova | Mariya Yakovlevna Zerova, alternately Marija Jakovlevna Zerova, (; April 7, 1902 – July 21, 1994) was a Ukrainian biologist and taxonomist known for her work in mycology.
Her research included work on ectrotrophic mycorrhiza and fungal diseases of the rubber tree (Hevea brasiliensis) and beet (Beta sp). She made a major contribution to the multi-volume books of the Determination of Mushrooms of Ukraine published between 1967 and 1979. Her collection of 12,000 specimens of fungi and plants is now held in the National Herbarium of Ukraine.
Education
In 1917, she left the Mariinsky Women's Gymnasium with a silver medal and entered the Kiev Medical Institute. However, she contracted tuberculosis and left after studying for three years. She then attended Kiev University, studying in the Faculty of Biology within the (then) Institute of Public Education. She graduated in 1924.
In 1942, Zerova defended a dissertation in mycology entitled Pleomorphism of some ascomycetes about the ontogenetic relationships of Ascomycota to the fungi imperfecti. In 1969, she was awarded a higher Doctor of Sciences degree for a thesis on the Study of the microflora of the USSR and mycorrhiza of the steppe part of Ukraine.
Career
After graduating, Zerova worked initially as a school teacher. However, she soon resumed a scientific career and spent her life studying fungal taxonomy, ecology and uses of fungi. After working at the Scientific Research Institute for Sugar Beet, in 1932 she was appointed head of the phytopathology department of the Scientific Research Institute of Rubber and Rubber Products. She studied the microflora and diseases of rubber plants and identified and described four new species of fungi: Macrosporium tausaghyzianum Zerova; Phyllosticta tausaghyziana Zerova; Myrothecium transchelianum Zerova & Tropova and Melanospora asclepiadis Zerova (a mycoparasite of Fusarium solani App. & Wr.).
She moved to an Institute for Forest Plantations and researched plant pathology and also how mycology could improve the establishment of trees and shrubs in landscaped urban areas. She identified over 400 species of fungi, some new to science, on 160 plant species.
In 1942 Zerova joined the MG Kholodny Institute of Botany of the USSR Academy of Sciences and remained there for the rest of her career. In 1963 she became head of the department of mycology, and from 1972 until her death in 1994 was a senior researcher-consultant. Research into mycorrhiza began at the Institute in the 1950s and her research moved into this area. She investigated the diversity of species associated with trees, shrubs and also the grasses and forbs of the Ukraine steppe. The specimens that she collected during this work are now kept in the National Herbarium of Ukraine within the Institute of Botany.
Later, in the 1960s, she worked on fungal classification including of the genera Inocybe and Dacryomstra. She applied the newly available technology of scanning electron microscopy in this research. She led research on increasing the number of fungal species harvested for human food, including developing cultivation methods for more species. These cultivation strategies were considered more important after the realisation that wild fungal fruiting bodies could accumulate heavy metals and radioactive isotopes from the soil. She also initiated research into medicinal properties of some of these species.
During her career she supervised postgraduate students and also gave lectures and seminars to the public as well as scientific conferences.
Publications
Zerova is the author or co-author of over 200 publications. These include books about the fungi of Ukraine.
M. Ya. Zerova, Edible and poisonous mushrooms of Ukraine (Їстівні та отруйні гриби України) (in Ukrainian, two editions, 1963 and 1970).
M. Ya. Zerova and SP Wasser, Edible and Poisonous Mushrooms of the Ukrainian Carpathians (Їстівні та отруйні гриби Українських Карпат) (in Ukrainian, 1972).
M. Ya. Zerova, Atlas of Mushrooms of Ukraine (Атлас грибів України) (in Ukrainian, 1974). With colour drawings of 550 species of mushrooms.
She was one of the authors of the Determination of mushrooms of Ukraine (Визначник грибів України), that was published in five volumes in seven books between 1967 and 1979, although work on it started in 1946. She contributed to Volume 2, on ascomycota and basidiomycota found in the Ukraine region, and also to Volume 3 where she provided a critical revision of the fungi imperfecti.
In the 60's Zerova published generalized works on the classification and evolution of ascomycetes.
Awards
In December 1983 Zerova was awarded the State Prize of Ukraine in Science and Technology in the field of science and technology for her contributions to the Determination of Mushrooms of Ukraine (1967–1979).
Personal life
She met and married Dmitry Zerov while she was a student at Kiev University. They had a child, zoologist Marina Zerova.
References
1902 births
1994 deaths
Soviet mycologists
Women mycologists
Ukrainian women biologists
20th-century Ukrainian women scientists
Laureates of the State Prize of Ukraine in Science and Technology
Soviet women biologists
Soviet biologists
Ukrainian Soviet Socialist Republic people
Taxonomists
Women taxonomists | Mariya Zerova | [
"Biology"
] | 1,178 | [
"Taxonomists",
"Taxonomy (biology)"
] |
54,431,682 | https://en.wikipedia.org/wiki/Relational%20constructivism | Relational constructivism can be perceived as a relational consequence of radical constructivism. In contrary to social constructivism, it picks up the epistemological threads and maintains the radical constructivist idea that humans cannot overcome their limited conditions of reception (i.e. self-referentially operating cognition). Therefore, humans are not able to come to objective conclusions about the world.
In spite of the subjectivity of human constructions of reality, relational constructivism focusses on the relational conditions applying to human perceptional processes. According to Björn Kraus:
It is substantial for relational constructivism that it basically originates from an epistemological point of view, thus from the subject and its construction processes. Coming from this perspective it then focusses on the (not only social, but also material) relations under which these cognitive construction processes are performed. Consequently, it's not only about social construction processes, but about cognitive construction processes performed under certain relational conditions.
Lifeworld and life conditions as relational constructions
In the course of recent constructivist discourses, a discussion about the term lifeworld took place. Björn Kraus' relational-constructivist version of the lifeworld term considers its phenomenological roots (Husserl and Schütz), but expands it within the range of epistemological constructivist theory building.
In consequence, a new approach is created, which focusses on the individual perspective upon the lifeworld term and takes account of social and material environmental conditions and their relevance, as emphasized, for example, by Jürgen Habermas. Essential therefore is Kraus' basic assumption that cognitive development depends on two determining factors. A person's own reality is their subjective construct, but this construct—in spite of all subjectivity—is not random: because a person is still linked to their environment, their own reality is influenced by the conditions of this environment (German: Grundsätzliche Doppelbindung menschlicher Strukturentwicklung).
Building up on this point of view, a separation of individual perception and the social and material environmental conditions is made possible. Kraus accordingly picks up the term lifeworld, adds the term "life conditions" (German: Lebenslage; originally introduced by philosophers Otto Neurath in 1931 as well as Gerhard Weisser in 1956) and opposes the two terms to each other.
By this means, lifeworld describes a person's subjectively experienced world, whereas life conditions describe the person's actual circumstances in life. Accordingly, it could be said a person's lifeworld is built depending on their particular life conditions. More precisely, the life conditions include the material and immaterial living circumstances as for example employment situation, availability of material resources, housing conditions, social environment as well as the person's physical condition. The lifeworld, in contrast, describes the subjective perception of these conditions.
Kraus uses the epistemological distinction between subjective reality and objective reality. Thus, a person's lifeworld correlates with the person's life conditions in the same way that subjective reality correlates with objective reality. One is the insurmountable, subjective construct built depending on the other one's conditions.
Kraus defined lifeworld and life conditions as follows:Life conditions mean a person's material and immaterial circumstances of life. Lifeworld means a person's subjective construction of reality, which he or she forms under the condition of his or her life circumstances.
This contrasting comparison provides a conceptual specification, enabling in the first step the distinction between a subjectively experienced world and its material and social conditions and allowing in the second step to focus on these conditions' relevance for the subjective construction of reality. With this in mind, Manfred Ferdinand, who is reviewing the lifeworld terms used by Alfred Schütz, Edmund Husserl, Björn Kraus and Ludwig Wittgenstein, concludes: "Kraus' thoughts on a constructivist comprehension of lifeworlds contours the integration of micro-, meso- and macroscopic approaches, as it is demanded by Invernizzi and Butterwege: This integration is not only necessary in order to relate the subjective perspectives and the objective frame conditions to each other but also because the objective frame conditions obtain their relevance for the subjective lifeworlds not before they are perceived and assessed."
A relational constructivist theory of power: Instructive vs. destructive power
Björn Kraus deals with the epistemological perspective upon power regarding the question about possibilities of interpersonal influence by developing a special form of constructivism ("Machtanalytischer Konstruktivismus").
Instead of focussing on the valuation and distribution of power, he asks what the term can describe at all. Coming from Max Weber's definition of power, he realizes the term of power has to be split into "instructive power" and "destructive power". More precisely, instructive power means the chance to determine the actions and thoughts of another person, whereas destructive power means the chance to diminish the opportunities of another person.
Kraus defined "instructive power" and "destructive power" as follows:"Instructive power" means the chance to determine a human's thinking or behaviour. (Instructive power as chance for instructive interaction is dependent on the instructed person's own will, which ultimately can refuse instructive power.) "Destructive power" means the chance to restrict a human's possibilities. (Destructive power as chance for destructive interaction is independent of the instructed person's own will, which can't refuse destructive power.)
How significant this distinction really is, becomes evident by looking at the possibilities of rejecting power attempts: rejecting instructive power is possible – rejecting destructive power is not. By using this distinction, proportions of power can be analyzed in a more sophisticated way, helping to sufficiently reflect on matters of responsibility. This perspective permits one to get over an "either-or-position" (either there is power, or there isn't), which is common especially in epistemological discourses about power theories, and to introduce the possibility of an "as well as-position".
According to Wolf Ritscher, it is Björn Kraus who "has reflected on the topic of power as a substantial aspect of social existence in a constructivist manner and has shown that constructivism can also be used in terms of social theory".
The systems term in relational constructivism
It is central to relational constructivism that social conditions cannot be recognized as allegedly objective, but are described from an observer position in social relationships on the basis of determined criteria. In this sense, for example, power is not seen as objectively recognizable, but as a relational phenomenon. Its description depends on the observers point of view. As with Weber, the definition of instructive power and destructive power focuses on the "opportunity within a social relation to put through one's own will, also against reluctance". Here, the category of power is not conceived as a per se existing but rather as a social phenomenon. In this respect, the terms instructive power and destructive power do not describe any observer-independent, existing units that a person has or attributes that are inherent in a person, but rather assertion potential in social relations.
The same applies to the relational-constructivist understanding of lifeworlds and living conditions: Although a person's living conditions seem to be much more accessible than a person's lifeworld by observation, both categories are always subject to the ever differing perspective of an observer. Nevertheless, it remains easier to describe life conditions than lifeworlds. While living conditions actually can be observed, statements about lifeworlds always refer to speculated cognitive constructs that cannot be accessed by observation.
For Kraus, it is important that systems cannot be defined as independent from an observer. This is the reason he names criteria allowing distinction between a system and its surrounding environment:
A system is a set of elements, which are determined as cohesive from an observer's perspective. Their relations to each other differ quantitatively and/or qualitatively from those to other entities. These observed differences allow to constitute a system border, distinguishing the system from its environment.
He concludes that it depends on these criteria and the observations made by the observing persons, whether systems can be identified or not.
Criticism and counter-criticism – loss of truth and "fake news"
Constructivist positions are accused with being "blind to the difference between truth and lies." It is problematized that truths only seem to exist in the plural and that the associated task of distinguishing between lies and truth is "dangerous on the one hand and inappropriate on the other".
Kraus takes a detailed look at this problem at various points and, using recourse to philosophical discourses of truth, clarifies that a distinction must first be made between "truth" and "truthfulness" and that the opposite of "truth" is not the "lie" but the "Falsehood". The counterpart of "truthfulness", on the other hand, is the category of "lies".
So there are the following comparisons: truth - falsehood and truthfulness - lie. Based on this, Kraus defines lie as a contradiction to the subjective belief that it is true.
A person's statement is considered a lie if it contradicts their own thinking of it as true.
Then he differentiates between lies (as deliberate false statements) and errors (as subjective thinking of something as true that is judged as not true or false). He also clarifies that it can only be decided from observer positions whether a statement is true or false, but that these decisions cannot be made arbitrarily, but must be reasonably justified.
In this respect, there can be no objective truth from the perspective of a constructivist epistemology, but it is still possible to justify when a statement should be considered true in terms of consensus and/or coherence.
Kraus claims that with this approach, it is also constructivistically possible to make a well-founded decision about the difference between news and fake news.
Literature
Kraus, Björn (2014): Introducing a model for analyzing the possibilities of power, help and control. In: Social Work and Society. International Online Journal. Retrieved 3 April 2019. (http://www.socwork.net/sws/article/view/393)
Kraus, Björn (2015): The Life We Live and the Life We Experience: Introducing the Epistemological Difference between "Lifeworld" (Lebenswelt) and "Life Conditions" (Lebenslage). In: Social Work and Society. International Online Journal. Retrieved 27 August 2018.(http://www.socwork.net/sws/article/view/438)
Kraus, Björn (2017): Plädoyer für den Relationalen Konstruktivismus und eine Relationale Soziale Arbeit. (Forum Sozial, 1/2017). (http://www.pedocs.de/frontdoor.php?source_opus=15381)
Kraus, Björn (2019): Relational constructivism and relational social work. In: Webb, Stephen, A. (edt.) The Routledge Handbook of Critical Social Work. Routledge international Handbooks. London and New York: Taylor & Francis Ltd.
Kraus, Björn (2019): Relationaler Konstruktivismus – Relationale Soziale Arbeit. Von der systemisch-konstruktivistischen Lebensweltorientierung zu einer relationalen Theorie der Sozialen Arbeit. Weinheim, München: Beltz, Juventa.
References
German philosophy
Social epistemology
Constructivism | Relational constructivism | [
"Technology"
] | 2,424 | [
"Social epistemology",
"Science and technology studies"
] |
54,431,721 | https://en.wikipedia.org/wiki/Algatron | The Algatron was a proposed and prototyped waste filtration and recycling system to be implemented on NASA missions. Designed and built by a pair of sanitary engineers at the University of California, Berkeley, William J. Oswald and Clarence Golueke, the Algatron relied on algae to provide carbon Dioxide absorption and oxygen generation as well as "microbiological waste conversion" for "humans sealed within an isolated capsule.". A working model was built by Oswald and Golueke in 1965 or 1966 under a contract by from the Air Force Cambridge Research Laboratories. Composed of two stacked cylinders lined with Algae, the cylinders would spin in opposite directions. With ports to allow sunlight in, nutrients (the waste and urine) were introduced via some overflow mechanism. Despite the promise that the Algatron represented, and the ways in which Oswald and Golueke "understood that the closed environment of the space capsule was itself just the a microcosm of the closed system of the earth's biosphere," the technology would never get past the prototype stage. NASA instead decided to go with fecal bags to deal with waste. The Russians developed a similar system, the BIOS-3, which got as far enough as a successful test run with human occupants in 1965.
See also
Assimitron
Biotron (disambiguation)
Eggatron
Phytotron
References
External links
The Algatron at World of Trons
David P.D. Munns, Engineering the Environment: Phytotrons and the Quest to Control Climate in the Cold War (University of Pittsburgh Press, 2017).
Atmospheric chemistry
Environmental science | Algatron | [
"Chemistry",
"Environmental_science"
] | 332 | [
"nan"
] |
54,431,812 | https://en.wikipedia.org/wiki/Honor%209 | The Honor 9 is a smartphone made by Huawei under their Honor sub-brand. It is a successor of the Huawei Honor 8 within the Honor N series.
Specifications
Hardware
The Honor 9 has a HiSilicon Kirin 960 octa-core processor (four 2.4 GHz cores and four 1.8 GHz cores), a Mali-G71 MP8 GPU, and a 3,200 mAh non-removable battery. It measures by by and weighs .
The phone comes with 64 or 128 gigabytes of storage and 4 GB or 6 GB of RAM, depending on the region. It has a display with a pixel resolution of 1920x1080 and pixel density of 428 ppi. The Honor 9 has an 8 MP front-facing camera and its dual rear camera setup consists of a 12 MP RGB lens and a 20-megapixel monochrome lens. It can record video in 4K and has electronic image stabilization for Full HD video. Other features include dual-SIM support, furthermore includes a USB-C port, and a fingerprint reader located on the lower bezel.
The Honor 9 has a metal frame and a 3D curved glass rear, and its official tagline is "the light catcher." The phone comes in "Glacier Grey," "Sapphire Blue," "Midnight Black," and gold, but some colors are not available in certain markets. During IFA 2017 in Berlin, Honor announced the new color variant for the Honor 9, which was the limited edition "Robin Egg Blue." The color became available in China in August, and was released in the United Kingdom in September.
Software
Huawei launched the Honor 9 with Android Nougat (version 7.0) and Huawei's EMUI 5.1. In the spring of 2019, Huawei began to roll out Android Pie (EMUI 9.0) for the device.
Release
The phone was released in China on June 12, 2017, revealed in Berlin on June 27, 2017, and became available for pre-ordering across United Kingdom on June 27, 2017.
Reception
Overall, initial reviews of the Honor 9 were positive, averaging 8.8 out of 10. Android Authority's Gary Sims gave the phone a rating of 8.7 out of 10, and wrote in his review summary: "The Honor 9 certainly ticks a lot of the right boxes: great performance, dual cameras, sleek design, and an IR blaster! The only downsides are the lack of toughened glass over the display and the slippery nature of the build materials." Andy Boxall of Digital Trends wrote the following as a summary of his review: "The Honor 9 impresses so much, it's a strong contender for one of the best reasonably priced smartphones available." PC Magazine Thomas Newton assigned the Honor 9 a rating of 4 out of 5, meaning "excellent". Swedroid offered its recommendation and rated the phone 8.3 out of 10 overall.
Jessica Murgia of AndroidPit, Dominic Preston of TechAdvisors, James Peckham of TechRadar, and ZDNet's Sandra Vogel each rated the phone 4.5 out of 5. Preston's summary read, "The Honor 9 is an undeniably impressive phone for an unmatched price right now. In performance terms, it's nipping at the heels of the year's top flagships, and only lacking flashy features like waterproofing or a bezel-less screen. It looks great, it runs fast, and it costs less than £400. We're sold." Summarizing his review, Peckham wrote, "The Honor 9 offers a lot of what the high-end flagship phones do right now, but for a much lower price. There's no exciting, headline-grabbing feature here, but a great design, fantastic performance and lots of nice touches make this an all-round impressive and affordable phone." Vogel also gave a rating of 8.9 on a 10-point scale, meaning "outstanding".
Android Central's Alex Dobie called the Honor 9 the "best phone for less than £400". He gave the phone the "Choice Award" and wrote, "The Honor 9 isn't perfect, but it is a great all-rounder that makes high-end performance and design more affordable than ever before." Stuff rated the Honor 9 five out of five stars and said, "High-end hardware at a middleweight price makes the Honor 9 one of the best phone deals around." TechRadar recommend the Honor 9, which won in the "Best Mid-range Phone" category at the 2017 T3 Awards.
References
External links
(CNET, 27 June 2017)
(Android Authority, 28 June 2017)
Mobile phones introduced in 2017
Phablets
Android (operating system) devices
Mobile phones with multiple rear cameras
Huawei Honor
Mobile phones with 4K video recording
Discontinued flagship smartphones
Mobile phones with infrared transmitter | Honor 9 | [
"Technology"
] | 1,019 | [
"Phablets",
"Crossover devices",
"Discontinued flagship smartphones",
"Flagship smartphones"
] |
54,431,929 | https://en.wikipedia.org/wiki/NGC%207019 | NGC 7019 is a spiral galaxy located about 480 million light-years away in the constellation of Capricornus. It was discovered by American astronomer Francis Leavenworth in 1886. It is host to a supermassive black hole with an estimated mass of with an estimated mass of 7.5 × 107 M☉.
See also
List of NGC objects (7001–7840)
References
External links
Spiral galaxies
Capricornus
7019
66107
Astronomical objects discovered in 1886 | NGC 7019 | [
"Astronomy"
] | 99 | [
"Capricornus",
"Constellations"
] |
54,432,193 | https://en.wikipedia.org/wiki/International%20Convention%20on%20Civil%20Liability%20for%20Bunker%20Oil%20Pollution%20Damage | The International Convention on Civil Liability for Bunker Oil Pollution Damage (BUNKER) is an International treaty listed and administered by the International Maritime Organization, signed in London on and in force generally on . The purpose is to adopt uniform international rules and procedures for determining questions of liability and providing adequate compensation.
In the convention, Bunker Oil is fuel used to power the ship. The convention covers leakage of that oil, and requires signatories to the convention to have their ships appropriately insured against such leakages.
It is associated with and references:
United Nations Convention on the Law of the Sea
International Convention on Civil Liability for Oil Pollution Damage (CLC [Convention])
International Convention on Liability and Compensation for Damage in Connection with the Carriage of Hazardous and Noxious Substances by Sea (HNS Convention)
International Convention for the Prevention of Pollution from Ships (MARPOL)
While BUNKER is apparently similar to CLC Convention – they are substantially different. Unlike the CLC, the BUNKER Convention is not limited to persistent fuel oils and will apply to any hydrocarbon used to operate the ship.
State parties
While the convention has been widely adopted, notable exceptions include Bolivia and Honduras — which are generally flag of convenience states—have not ratified the treaty. As with the CLC, the United States of America was a driver behind the BUNKER convention, and had legislation in place similar to BUNKER provisions, the Oil Pollution Act of 1990, hence it claimed, the treaty did not need to be signed.
As of November 2018, the treaty has been ratified by 90 states.
References
External links
IMO Brochure on Civil Liability for Bunker Oil Pollution Damage
Treaties of Albania
Treaties of Antigua and Barbuda
Treaties of Australia
Treaties of Austria
Treaties of Azerbaijan
Treaties of the Bahamas
Treaties of Bahrain
Treaties of Barbados
Treaties of Belgium
Treaties of Belize
Treaties of Brazil
Treaties of Bulgaria
Treaties of Canada
Treaties of China
Treaties of the Comoros
Treaties of the Republic of the Congo
Treaties of the Cook Islands
Treaties of Croatia
Treaties of Cyprus
Treaties of the Czech Republic
Treaties of Ivory Coast
Treaties of Denmark
Treaties of Djibouti
Treaties of Egypt
Treaties of Estonia
Treaties of Ethiopia
Treaties of Fiji
Treaties of Finland
Treaties of France
Treaties of Georgia (country)
Treaties of Germany
Treaties of Greece
Treaties of Grenada
Treaties of Hungary
Treaties of Indonesia
Treaties of Iran
Treaties of Ireland
Treaties of Italy
Treaties of Jamaica
Treaties of Jordan
Treaties of Kenya
Treaties of Kiribati
Treaties of North Korea
Treaties of South Korea
Treaties of Latvia
Treaties of Liberia
Treaties of Lithuania
Treaties of Luxembourg
Treaties of Madagascar
Treaties of Malaysia
Treaties of Malta
Treaties of the Marshall Islands
Treaties of Mauritius
Treaties of Mongolia
Treaties of Montenegro
Treaties of Morocco
Treaties of Myanmar
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Treaties of Niue
Treaties of Norway
Treaties of Palau
Treaties of Panama
Treaties of Poland
Treaties of Portugal
Treaties of Romania
Treaties of Russia
Treaties of Saint Kitts and Nevis
Treaties of Saint Lucia
Treaties of Saint Vincent and the Grenadines
Treaties of Samoa
Treaties of Serbia
Treaties of Sierra Leone
Treaties of Singapore
Treaties of Slovakia
Treaties of Slovenia
Treaties of Spain
Treaties of Sweden
Treaties of Switzerland
Treaties of Syria
Treaties of Togo
Treaties of Tonga
Treaties of Tunisia
Treaties of Turkey
Treaties of Tuvalu
Treaties of the United Kingdom
Treaties of Vanuatu
Treaties of Vietnam
2001 in the environment
2008 in the environment
Environmental treaties
Environmental impact of shipping
International Maritime Organization treaties
Law of the sea treaties
Liability treaties
Oil spills
Treaties concluded in 2001
Treaties entered into force in 2008
2001 in London
Treaties extended to the Isle of Man
Treaties extended to Gibraltar
Treaties extended to Bermuda
Treaties extended to the Cayman Islands
Treaties extended to the British Virgin Islands
Treaties extended to Macau
Treaties extended to Hong Kong | International Convention on Civil Liability for Bunker Oil Pollution Damage | [
"Chemistry",
"Environmental_science"
] | 725 | [
"Oil spills",
"Water pollution"
] |
54,432,896 | https://en.wikipedia.org/wiki/Androstanolone | Androstanolone, or stanolone, also known as dihydrotestosterone (DHT) and sold under the brand name Andractim among others, is an androgen and anabolic steroid (AAS) medication and hormone which is used mainly in the treatment of low testosterone levels in men. It is also used to treat breast development and small penis in males.
Compared to testosterone, androstanolone (DHT) is less likely to aromatize into estrogen, and therefore it shows less pronounced estrogenic side effects, such as gynecomastia and water retention. On the other hand, androstanolone (DHT) show more significant androgenic side effects, such as acne, hair loss and prostate enlargement.
It has strong androgenic effects and muscle-building effects, as well as relatively weak estrogenic effects.
It is typically given as a gel for application to the skin, but can also be used as an ester by injection into muscle.
Side effects of androstanolone include symptoms of masculinization like acne, increased hair growth, voice changes, and increased sexual desire. The medication is a naturally occurring androgen and anabolic steroid and hence is an agonist of the androgen receptor (AR), the biological target of androgens like testosterone and DHT.
Androstanolone was discovered in 1935 and was introduced for medical use in 1953. It is used mostly in France and Belgium. The drug has been used by weightlifters to increase performance due to its powerful androgenic properties. The medication is a controlled substance in many countries and so non-medical use is generally illicit.
Medical uses
Androstanolone is available in pharmaceutical formulations for medical use as an androgen. It is used mainly as a form of androgen replacement therapy in the treatment of male hypogonadism and is specifically approved for this indication in certain countries. However, it is no longer recommended for this purpose due to biological differences from testosterone such as lack of estrogenic effects and partial androgenic effects. Topical androstanolone is useful in the treatment of gynecomastia. Similarly, androstanolone enanthate via intramuscular injection has been found to be effective in the treatment persistent pubertal gynecomastia. The medication has also been used as a topical gel to treat small penis in pre- and peripubertal boys with mild or partial androgen insensitivity syndrome.
Androstanolone was found to be effective in the treatment of advanced breast cancer in women in the 1950s, although it was used in very high doses and caused severe virilization. It was used as a microcrystalline aqueous suspension by intramuscular injection. Shortly thereafter, drostanolone propionate (2α-methylandrostanolone propionate) was developed for this use instead of androstanolone due to its superior pharmacokinetics and was introduced for this indication in the United States and Europe in the early 1960s.
Androstanolone was used at a dose of 25 mg sublingually two to three times per day in androgen replacement therapy for men. This is also the anabolic dosage of androstanolone in men.
Available forms
Androstanolone is available as a 2.5% hydroalcoholic gel given transdermally in doses of 5 or 10 g/day (brand name Andractim). The medication was previously available as a 10 mg oral tablet with 300 mg L-lysine (brand name Lysinex) and as a 25 mg sublingual tablet (brand names Anabolex, Anaprotin, Anabolene, Anaboleen, Proteina). The medication has also been marketed in the form of several androstanolone esters, including androstanolone benzoate (brand names Ermalone-Amp, Hermalone, Sarcosan), androstanolone enanthate (brand name Anaboleen Depot), androstanolone propionate (brand name Pesomax), and androstanolone valerate (brand name Apeton), which are provided as oil solutions for intramuscular injection at regular intervals.
Side effects
Adverse effects of androstanolone are similar to those of other AAS and include androgenic side effects like oily skin, acne, seborrhea, increased facial/body hair growth, scalp hair loss, and increased aggressiveness and sex drive. In women, androstanolone can cause partially irreversible virilization, for instance voice deepening, hirsutism, clitoromegaly, breast atrophy, and muscle hypertrophy, as well as menstrual disturbances and reversible infertility. In men, the medication may also cause hypogonadism, testicular atrophy, and reversible infertility at sufficiently high dosages.
Androstanolone can have adverse effects on the cardiovascular system, especially with long-term administration of high dosages. AAS like androstanolone stimulate erythropoiesis (red blood cell production) and increase hematocrit levels and at high dosages can cause polycythemia (overproduction of red blood cells), which can greatly increase the risk of thrombic events such as embolism and stroke. Unlike many other AAS, androstanolone is not aromatized into estrogens and hence has no risk of estrogenic side effects like gynecomastia, fluid retention, or edema. In addition, as it is not a 17α-alkylated AAS and is administered parenterally, androstanolone has no risk of hepatotoxicity.
It has been theorized that androstanolone may have less risk of benign prostatic hyperplasia and prostate cancer than testosterone because it is not aromatized into estrogens. This is relevant because estrogens are thought to possibly be necessary for the manifestation of these diseases. In accordance, androstanolone has been found to not increase prostate gland size in men. Conversely, due to lack of aromatization into estrogens, androstanolone therapy for androgen replacement may result in decreased bone mineral density, incomplete effects in the brain, and undesirable changes in cholesterol levels.
Pharmacology
Pharmacodynamics
Androstanolone is a potent agonist of the AR. It has an affinity (Kd) of 0.25 to 0.5 nM for the human AR, which is about 2- to 3-fold higher than that of testosterone (Kd = 0.4 to 1.0 nM) and the dissociation rate of androstanolone from the AR is also about 5-fold slower than that of testosterone. The EC50 of androstanolone for activation of the AR is 0.13 nM, which is about 5-fold stronger than that of testosterone (EC50 = 0.66 nM). In bioassays, androstanolone has been found to be 2.5- to 10-fold more potent than testosterone. Upon intramuscular injection in rats, androstanolone is about 1.5- to 2.5-fold the potency of testosterone.
Unlike testosterone and various other AAS, androstanolone cannot be aromatized, and for this reason, poses no risk of estrogenic side effects like gynecomastia at any dosage. In addition, androstanolone cannot be metabolized by 5α-reductase (as it is already 5α-reduced), and for this reason, is not potentiated in so-called "androgenic" tissues like the skin, hair follicles, and prostate gland, thereby improving its ratio of anabolic to androgenic effects. However, androstanolone is nonetheless described as a very poor anabolic agent. This is attributed to its high affinity as a substrate for 3α-hydroxysteroid dehydrogenase (3α-HSD), which is highly expressed in skeletal muscle and inactivates androstanolone into 3α-androstanediol, a metabolite with very weak AR activity. Unlike androstanolone, testosterone is very resistant to metabolism by 3α-HSD, and so is not similarly inactivated in skeletal muscle. For the preceding reasons, androstanolone has been described as a "partial androgen".
Pharmacokinetics
Absorption
The bioavailability of androstanolone differs considerably depending on its route of administration. Its oral bioavailability is very low, and androstanolone has been considered to be ineffective by the oral route. However, it has been used orally, and is described as a weak AAS by this route. The transdermal bioavailability of androstanolone is approximately 10%. Its bioavailability with intramuscular injection, on the other hand, is complete (100%).
Doses of topical androstanolone gel of 16, 32, and 64 mg have been found to produce total testosterone and DHT levels in the low, mid, and high normal adult male range, respectively.
Distribution
The plasma protein binding of androstanolone is about 98.5 to 99.0%. It is bound 50 to 80% to sex hormone-binding globulin, 20 to 40% to albumin, and less than 0.5% to corticosteroid-binding globulin, with about 1.0 to 1.5% circulating freely or unbound.
Metabolism
The terminal half-life of androstanolone in the circulation (53 minutes) is longer than that of testosterone (34 minutes), and this may account for some of the difference in their potency. A study of transdermal androstanolone and testosterone therapy reported terminal half-lives of 2.83 hours and 1.29 hours, respectively.
Chemistry
Androstanolone, also known as 5α-androstan-17β-ol-3-one or as 5α-dihydrotestosterone (5α-DHT), is a naturally occurring androstane steroid with a ketone group at the C3 position and a hydroxyl group at the C17β position. It is the derivative of testosterone in which the double bond between the C4 and C5 positions has been reduced or hydrogenated.
Esters
Several C17β ester prodrugs of androstanolone, including androstanolone benzoate, androstanolone enanthate, androstanolone propionate, and androstanolone valerate, have been developed and introduced for medical use as AAS. Conversely, dihydrotestosterone acetate, dihydrotestosterone butyrate, and dihydrotestosterone formate have been developed but have not been marketed.
Derivatives
Synthetic derivatives of androstanolone (DHT) that have been developed as AAS include:
Non-17α-alkylated derivatives
Marketed
Bolazine (an azine dimer prodrug of drostanolone)
Drostanolone (2α-methyl-DHT)
Epitiostanol (2α,3α-epithio-DHT)
Mepitiostane (a 17-ether prodrug of epitiostanol)
Mesterolone (1α-methyl-DHT)
Metenolone (1-methyl-δ1-DHT)
Stenbolone (2-methyl-δ1-DHT)
Never marketed
1-Testosterone (dihydroboldenone; δ1-DHT)
Mesabolone (a 17-ether prodrug of δ1-DHT)
Prostanozol (a 17-ether prodrug of 17α-demethylstanozolol)
17α-Alkylated derivatives
Marketed
Androisoxazole (a 2,3-isoxazole A ring-fused derivative of 17α-methyl-DHT)
Furazabol (a 2,3-furan A ring-fused derivative of 17α-methyl-DHT)
Mebolazine (an azine dimer prodrug of methasterone)
Mestanolone (17α-methyl-DHT)
Oxandrolone (2-oxa-17α-methyl-DHT)
Oxymetholone (2-hydroxymethylene-17α-methyl-DHT)
Stanozolol (a 2,3-pyrazole A ring-fused derivative of 17α-methyl-DHT)
Never marketed
Desoxymethyltestosterone (3-deketo-17α-methyl-δ2-DHT)
Methasterone (2α,17α-dimethyl-DHT)
Methyl-1-testosterone (methyldihydroboldenone; 17α-methyl-δ1-DHT)
Methylepitiostanol (2α,3α-epithio-17α-methyl-DHT)
Methylstenbolone (2,17α-dimethyl-δ1-DHT)
History
Androstanolone was first discovered and synthesized in 1935 by Adolf Butenandt and his colleagues. It was first introduced for medical use in 1953, under the brand name Neodrol in the United States, and was subsequently marketed in the United Kingdom and other European countries. Transdermal androstanolone gel has been available in France since 1982.
Society and culture
Generic names
When used as a drug, androstanolone is referred to as androstanolone () or as stanolone () rather than as DHT.
Brand names
Brand names of androstanolone include Anaboleen, Anabolex, Anaprotin (), Andractim (formerly AndroGel-DHT) (, , ), Androlone, Apeton, Gelovit (), Neodrol, Ophtovital (), Pesomax (), Stanaprol, and Stanolone, among others.
Availability
The availability of pharmaceutical androstanolone is limited; it is not available in the United States or Canada, but it is or has been available in certain European countries, including the United Kingdom, Germany, France, Spain, Italy, Belgium, and Luxembourg.
The available formulations of androstanolone include buccal or sublingual tablets (Anabolex, Stanolone), topical gels (Andractim, Gelovit, Ophtovital), and, as esters in oil, injectables like androstanolone propionate (Pesomax) and androstanolone valerate (Apeton). Androstanolone benzoate (Ermalone-Amp, Hermalone, Sarcosan) and androstanolone enanthate (Anaboleen Depot) are additional androstanolone esters that are available for medical use in some countries. Androstanolone esters act as prodrugs of androstanolone in the body and have a long-lasting depot effect when given via intramuscular injection.
Legal status
Androstanolone, along with other AAS, is a schedule III controlled substance in the United States under the Controlled Substances Act.
Androstanolone is on the World Anti-Doping Agency's list of prohibited substances, and is therefore banned from use in most major sports.
Research
In the early- to mid-2000s, transdermal or topical androstanolone was under development in the United States for the treatment of hypogonadism (as a form of androgen replacement therapy), male osteoporosis, and cachexia (in cancer patients) and in Australia for the treatment of benign prostatic hyperplasia (BPH). It reached phase II clinical trials for hypogonadism and BPH and phase III clinical studies for cachexia but development was ultimately never completed for these indications in these specific countries. Although androstanolone itself has not been approved for cachexia in any country, an orally active synthetic derivative of androstanolone, oxandrolone (2-oxa-17α-methylandrostanolone), is approved and used for this indication in the United States.
Topical androgens like androstanolone have been used and studied in the treatment of cellulite in women. Topical androstanolone on the abdomen has also been found to significantly decrease subcutaneous abdominal fat in women, and hence may be useful for improving body silhouette. However, men and hyperandrogenic women have higher amounts of abdominal fat than healthy women, and androgen therapy has been found to increase abdominal fat in postmenopausal women and transgender men.
References
External links
Androstanolone (for hypogonadism and cachexia) - AdisInsight
Androstanolone (for hypogonadism and BPH) - AdisInsight
Androstanolone (for male osteoporosis) - AdisInsight
5α-Reduced steroid metabolites
Secondary alcohols
Anabolic–androgenic steroids
Androstanes
Estrogens
GABAA receptor positive allosteric modulators
Ketones
Testosterone | Androstanolone | [
"Chemistry"
] | 3,721 | [
"Ketones",
"Functional groups"
] |
54,434,510 | https://en.wikipedia.org/wiki/Aspergillus%20waksmanii | Aspergillus waksmanii is a homothallic species of fungus in the genus Aspergillus which has been isolated from soil from New Jersey in the United States. It is from the Fumigati section. Several fungi from this section produce heat-resistant ascospores, and the isolates from this section are frequently obtained from locations where natural fires have previously occurred. Aspergillus waksmanii produces apolar indoloterpenes.
Growth and morphology
A. waksmanii has been cultivated on both Czapek yeast extract agar (CYA) plates and Malt Extract Agar Oxoid® (MEAOX) plates. The growth morphology of the colonies can be seen in the pictures below.
References
Further reading
waksmanii
Fungi described in 2013
Fungus species | Aspergillus waksmanii | [
"Biology"
] | 169 | [
"Fungi",
"Fungus species"
] |
54,434,600 | https://en.wikipedia.org/wiki/25%20great%20circles%20of%20the%20spherical%20octahedron | In geometry, the 25 great circles of the spherical octahedron is an arrangement of 25 great circles in octahedral symmetry. It was first identified by Buckminster Fuller and is used in construction of geodesic domes.
Construction
The 25 great circles can be seen in 3 sets: 12, 9, and 4, each representing edges of a polyhedron projected onto a sphere. Nine great circles represent the edges of a disdyakis dodecahedron, the dual of a truncated cuboctahedron. Four more great circles represent the edges of a cuboctahedron, and the last twelve great circles connect edge-centers of the octahedron to centers of other triangles.
See also
31 great circles of the spherical icosahedron
References
Edward Popko, Divided Spheres: Geodesics and the Orderly Subdivision of the Sphere, 2012, pp 21–22.
Vector Equilibrium and its Transformation Pathways
Geodesic domes
Polyhedra
Circles | 25 great circles of the spherical octahedron | [
"Mathematics"
] | 193 | [
"Circles",
"Pi",
"Geometry",
"Geometry stubs"
] |
54,434,626 | https://en.wikipedia.org/wiki/June%20Huh | June E Huh (; born June 9, 1983) is an Korean American mathematician who is currently a professor at Princeton University. Previously, he was a professor at Stanford University. He was awarded the Fields Medal and a MacArthur Fellowship in 2022. He has been noted for the linkages that he has found between algebraic geometry and combinatorics.
Early life and education
Huh was born in Stanford, California while his parents were completing graduate school at Stanford University. He was raised in South Korea, where his family returned when he was approximately two years old. His father was a professor of statistics at Korea University, while his mother was a professor of Russian language at Seoul National University. Poor scores on elementary school tests convinced him that he lacked the innate aptitude to excel in mathematics. He later dropped out of high school to focus on writing poetry after becoming bored and exhausted by the constant routine of relentless
studying. Huh has been described as a late bloomer, both in terms of his career phenomena and with regards to his academic and professional development. Huh matriculated at Seoul National University in 2002, but found himself initially unsettled. He pinned his initial career aspirations on becoming a science journalist and decided to major in physics and astronomy, but compiled a poor attendance record and had to repeat several courses that he initially failed at.
Early in his studies he was mentored by Japanese award-winning mathematician Heisuke Hironaka, who went to Seoul National University as a visiting professor. Having failed several courses, Huh took an algebraic geometry course under Hironaka in his sixth year which focused on singularity theory and was based on Hironaka's current research rather than established teaching material. Huh credited the course with sparking his interest in research-level math. Huh then proceeded to complete a master's degree at Seoul National University, while frequently travelling to Japan with Hironaka and acting as his personal assistant. Due to his poor academic record as an undergraduate, Huh was rejected from all but one of the American universities that he applied to. He started his Ph.D. studies at the University of Illinois Urbana-Champaign in 2009, before transferring to the University of Michigan in 2011. He graduated in 2014 with a thesis written under the direction of Mircea Mustață at the age of 31. He was awarded the Sumner Byron Myers Prize for his PhD thesis.
Career
In 2009, during his PhD studies, Huh proved Read's conjecture about the unimodality of the coefficients of chromatic polynomials in graph theory, which had been unresolved for more than 40 years. In joint work with Karim Adiprasito and Eric Katz, he resolved the Heron–Rota–Welsh conjecture on the log-concavity of the characteristic polynomial of matroids.
With Karim Adiprasito, he is one of five winners of the 2019 New Horizons in Mathematics Prize, associated with the Breakthrough Prize in Mathematics. He was a winner of Blavatnik Award for Young Scientists (U.S. Regional) in 2017. In 2018, Huh was an invited speaker at the International Congress of Mathematicians in Rio de Janeiro. In 2021, he received the Samsung Ho-Am Prize in Science for physics and mathematics.
Huh was awarded the 2022 Fields Medal for "bringing the ideas of Hodge theory to combinatorics, the proof of the Dowling–Wilson conjecture for geometric lattices, the proof of the Heron–Rota–Welsh conjecture for matroids, the development of the theory of Lorentzian polynomials, and the proof of the strong Mason conjecture".
Huh is the seventh recipient of East Asian ancestry and the first winner of Korean ancestry to have the prize bestowed upon him.
Personal life
Huh is married to Kim Nayoung, whom he met during his studies while attending Seoul National University. Kim is a graduate of Seoul National University where she earned her doctorate in mathematics. The couple has two sons.
References
External links
1983 births
Living people
21st-century American mathematicians
Algebraic geometers
American academics of Korean descent
American expatriates in South Korea
Combinatorialists
Fields Medalists
Institute for Advanced Study visiting scholars
Mathematicians from California
MacArthur Fellows
People from Stanford, California
Princeton University faculty
Recipients of the Ho-Am Prize in Science
Seoul National University alumni
Stanford University Department of Mathematics faculty
University of Michigan alumni
University of Illinois Urbana-Champaign alumni | June Huh | [
"Mathematics"
] | 873 | [
"Combinatorialists",
"Combinatorics"
] |
54,434,627 | https://en.wikipedia.org/wiki/Eric%20Katz | Eric Katz is a mathematician working in combinatorial algebraic geometry and arithmetic geometry. He is currently an associate professor in the Department of Mathematics at Ohio State University.
In joint work with Karim Adiprasito and June Huh, he resolved the Heron–Rota–Welsh conjecture on the log-concavity of the characteristic polynomial of matroids. With Joseph Rabinoff and David Zureick-Brown, he has given bounds on rational and torsion points on curves.
Education
Katz went to Beachwood High School, in Beachwood, Ohio, a suburb of Cleveland. After earning a Bachelor of Science in Mathematics from Ohio State University in 1999, he pursued graduate studies at Stanford University, obtaining his Doctor of Philosophy in 2004 with a thesis written under the direction of Yakov Eliashberg and Ravi Vakil.
References
Year of birth missing (living people)
1970s births
Living people
Ohio State University faculty
Academic staff of the University of Waterloo
Stanford University alumni
Academics from Cleveland
Mathematicians from Ohio
Algebraic geometers
Combinatorialists
20th-century American mathematicians
21st-century American mathematicians
Ohio State University College of Arts and Sciences alumni | Eric Katz | [
"Mathematics"
] | 227 | [
"Combinatorialists",
"Combinatorics"
] |
54,435,596 | https://en.wikipedia.org/wiki/Florivore | In zoology, a florivore (not to be confused with a folivore) is an animal which mainly eats products of flowers. Florivores are types of herbivores (often referred to as floral herbivores), yet within the feeding behaviour of florivory, there are a range of other more specific feeding behaviours, including, but not limited to:
Granivory: the consumption of grain and seeds
Nectarivory: the consumption of flower nectar
Palynivory: the consumption of flower pollen
Frugivory: the consumption of fruit
Diet
A florivore's diet consists of bulky foodstuffs, including the items mentioned above, yet also bark, roots, and similar items. Many florivores are also omnivores, meaning that their diets can also be supplemented by various small insects, for instance.
Examples
The majority of birds in the Psittacine family are florivores, which includes most parrots, parakeets, macaws, and cockatoos. Other notable florivores are hummingbirds, sparrows, and toucans. The crab-eating macaque acts as an invasive florivore in Mauritius, where it forages voraciously on flowers of native plants, including the endangered, endemic Roussea simplex.
See also
Herbivore
Frugivore
Nectarivore
Palynivore
Granivore
References
External links
Bibliography
Approaches to Plant Evolutionary Ecology by G.P. Cheplick
Poultry Nutrition: A Comparative Approach by K. C. Klasing (Department of animal science, University of California, Davis, California 95616, 2005)
Animals by eating behaviors
Herbivory | Florivore | [
"Biology"
] | 354 | [
"Behavior",
"Animals by eating behaviors",
"Eating behaviors",
"Herbivory",
"Ethology"
] |
54,436,343 | https://en.wikipedia.org/wiki/Propionyl%20chloride | Propionyl chloride (also propanoyl chloride) is the organic compound with the formula CH3CH2C(O)Cl. It is the acyl chloride derivative of propionic acid. It undergoes the characteristic reactions of acyl chlorides. It is a colorless, corrosive, volatile liquid.
It is used as a reagent for organic synthesis. In derived chiral amides and esters, the methylene protons are diastereotopic.
There have been efforts to schedule Propionyl chloride as a DEA List 1 Chemical as it can be used to synthesize fentanyl.
Synthesis
Propionyl chloride is industrially produced by chlorination of propionic acid with phosgene:
CH3CH2CO2H + COCl2 → CH3CH2COCl + HCl + CO2
References
Acyl chlorides
Reagents for organic chemistry | Propionyl chloride | [
"Chemistry"
] | 189 | [
"Reagents for organic chemistry"
] |
54,436,381 | https://en.wikipedia.org/wiki/Pentanoyl%20chloride | Pentanoyl chloride is an acyl chloride derived from pentanoic acid. It is a colorless liquid that is used to attach the valeroyl group. It is usually produced by chlorination of valeric acid.
Reactions
Like related acyl chlorides, valeryl chloride hydrolyzes readily:
CH3(CH2)3C(O)Cl + H2O → CH3(CH2)3CO2H + HCl
Alcohols react to give esters:
CH3(CH2)3C(O)Cl + ROH → CH3(CH2)3CO2R + HCl
Amines react to give amides:
CH3(CH2)3C(O)Cl + R2NH → CH3(CH2)3C(O)NR2 + HCl
Benzene reacts under conditions of the Friedel-Crafts reaction to give valerophenone:
CH3(CH2)3C(O)Cl + C6H6 → CH3(CH2)3C(O)C6H5 + HCl
References
Acyl chlorides
Reagents for organic chemistry | Pentanoyl chloride | [
"Chemistry"
] | 239 | [
"Reagents for organic chemistry"
] |
54,437,591 | https://en.wikipedia.org/wiki/Isobutyryl%20chloride | Isobutyryl chloride (2-methylpropanoyl chloride) is the organic compound with the formula . A colorless liquid, it the simplest branched-chain acyl chloride. It is prepared by chlorination of isobutyric acid.
Reactions
As an ordinary acid chloride, isobutyryl chloride is the subject of many reported transformations. Dehydrohalogenation of isobutyryl chloride with triethylamine gives 2,2,4,4-tetramethylcyclobutanedione. Treatment of isobutyryl chloride with hydrogen fluoride gives the acid fluoride.
References
Acyl chlorides
Reagents for organic chemistry | Isobutyryl chloride | [
"Chemistry"
] | 142 | [
"Organic compounds",
"Organic compound stubs",
"Organic chemistry stubs",
"Reagents for organic chemistry"
] |
54,437,604 | https://en.wikipedia.org/wiki/Pivaloyl%20chloride | 2,2-Dimethylpropanoyl chloride is a branched-chain acyl chloride. It was first made by Aleksandr Butlerov in 1874 by reacting pivalic acid with phosphorus pentachloride.
Pivaloyl chloride is used as an input in the manufacture of some drugs, insecticides and herbicides.
References
Acyl chlorides
Reagents for organic chemistry | Pivaloyl chloride | [
"Chemistry"
] | 80 | [
"Organic chemistry stubs",
"Reagents for organic chemistry"
] |
71,610,673 | https://en.wikipedia.org/wiki/Time%20in%20Equatorial%20Guinea | Time in Equatorial Guinea is given by a single time zone, denoted as West Africa Time (WAT; UTC+01:00). Equatorial Guinea shares this time zone with several other countries, including fourteen in western Africa. Equatorial Guinea does not observe daylight saving time (DST).
IANA time zone database
In the IANA time zone database, Equatorial Guinea is given one zone in the file zone.tab—Africa/Malabo. "GQ" refers to the country's ISO 3166-1 alpha-2 country code. Data for Equatorial Guinea directly from zone.tab of the IANA time zone database; columns marked with * are the columns from zone.tab itself:
See also
Time in Africa
List of time zones by country
References
External links
Current time in Equatorial Guinea at Time.is
Time in Equatorial Guinea at TimeAndDate.com
Time by country
Geography of Equatorial Guinea
Time in Africa | Time in Equatorial Guinea | [
"Physics"
] | 184 | [
"Spacetime",
"Physical quantities",
"Time",
"Time by country"
] |
71,615,633 | https://en.wikipedia.org/wiki/LHS%203844 | LHS 3844, formally named Batsũ̀, is a red dwarf star located away from the Solar System in the constellation of Indus. The star has about 15% the mass and 19% the radius of the Sun. It is a relatively inactive red dwarf with a slow rotation period of about 128 days, though UV flares have been observed. LHS 3844 is orbited by one known exoplanet.
Nomenclature
The designation LHS 3844 comes from one of Luyten's catalogues of stars with high proper motion.
In August 2022, this planetary system was included among 20 systems to be named by the third NameExoWorlds project. The approved names, proposed by a team from Costa Rica, were announced in June 2023. LHS 3844 is named Batsũ̀ and its planet is named Kua'kua, after the Bribri words for "hummingbird" and "butterfly".
Planetary system
The exoplanet LHS 3844 b was discovered in 2018 using TESS. It is a terrestrial planet larger than Earth with an orbital period of less than a day, and likely does not have an atmosphere. Its low albedo suggests that its surface may resemble that of the Moon or Mercury.
References
Indus (constellation)
M-type main-sequence stars
Planetary systems with one confirmed planet
0136
Batsũ̀ | LHS 3844 | [
"Astronomy"
] | 276 | [
"Indus (constellation)",
"Constellations"
] |
71,615,698 | https://en.wikipedia.org/wiki/Intracellular%20delivery | Intracellular delivery is the process of introducing external materials into living cells. Materials that are delivered into cells include nucleic acids (DNA and RNA), proteins, peptides, impermeable small molecules, synthetic nanomaterials, organelles, and micron-scale tracers, devices and objects. Such molecules and materials can be used to investigate cellular behavior, engineer cell operations or correct a pathological function.
Medical applications of intracellular delivery range from in vitro fertilisation (IVF) and mRNA vaccines to gene therapy and preparation of CAR-T cells. Industrial applications include protein production, biomanufacture, and genetic engineering of plants and animals. Intracellular delivery is a fundamental technique in the study of biology and genetics, such as the use of DNA plasmid transfection to investigate protein function in living cells. A wide range of approaches exist for performing intracellular delivery including biological, chemical and physical techniques that work through either membrane disruption or packaging the delivery material in carriers.
Intracellular delivery is at the intersection of cell biology and technology, and is related to many fields across science and medicine including genetics, biotechnology, bioengineering and drug delivery.
Applications
Analogous to the way computers operate through electronic signals, cells process and transmit information through molecules. Depending on the molecules and materials that are loaded into cells, different outcomes or applications can be achieved (see Figure "Applications of Intracellular Delivery" for examples). Below are some of the main classifications of cargo materials used to investigate and engineer cells through intracellular delivery.
Cargo Types
Nucleic Acids
Transfection refers to the intracellular delivery of nucleic acids: DNA, RNA and their analogues. Nucleic acids materials that are commonly transfected into cells are plasmid DNA, mRNA, siRNA, and oligonucleotides. The transfection applications span across 3 main areas:
Basic biological research,
biomanufacture, and
gene and cell-based therapies
In basic research, transfection is a cornerstone technique in fields ranging from cell biology and genetics to immunology and drug discovery. In biomanufacture, transfection is used for production of proteins, antibodies, viral vectors, and virus-like particles for vaccines. In cell-based therapies transfection is used for applications such as ex-vivo gene therapy, hematopoietic stem cell engineering, production of induced pluripotent stem cells, and ex-vivo preparation of cells for immunotherapy Over the last 50 years nucleic acid transfection has been the most common subcategory of intracellular delivery.
Plasmid DNA began to be transfected into animal cells for the purpose of gene expression in the late 1970s via microinjection
and calcium phosphate methods. Since then, it has been used to investigate gene and protein function in manifold studies. DNA plasmids are physically large and cumbersome molecules with a 5-10 kilo-basepair plasmid being >100 nm diameter in solution when free and uncondensed. Nevertheless, due to the well-established and relatively low-cost techniques for editing and preparing them, they have been very commonly used in biological research.
In the 1970s it was shown that microinjection of mRNA resulted in protein expression. In certain situations, mRNA transfection is considered advantageous for inducing protein expression compared with DNA plasmids due the following reasons
reduced risk of genomic integration,
does not require nuclear delivery with cytosolic delivery being sufficient,
protein expression is dose-dependent and rapid,
less toxic and immunogenic than DNA vectors when appropriately chemically modified.
Thus, mRNA is considered a better option than DNA for most therapeutic applications although it is more expensive and intrinsically unstable.
Oligonucleotides are single or double-stranded sequences of DNA or RNA of less than 30 nucleotides in length. Small interfering RNA (siRNAs) are short 21-22 base pair duplexes of RNA that can be transfected into cells to silence gene expression
. Since their Nobel prize winning discovery in 1998, siRNA have been transfected into cells in thousands of biological studies in order to perturb gene function. Other oligonucleotides of interest for intracellular delivery include antisense oligonucleotides (ASOs), micro RNAs (miRNAs), and aptamers. Such oligonucleotides can be used to alter cell behaviour through several different mechanisms.
Lipid nanoparticles and electroporation are currently widespread strategies for nucleic acid transfection. However, effective transfection remains a hurdle in many primary cells, stem cells, patient-derived cells and neurons. The ability to conduct biological research and carry out potential medical applications in such cells is often limited by transfection efficiency and tolerance to treatment. Furthermore, there is currently a poor understanding of the long-term effects of performing transfection on cells within the human body.
Proteins and Peptides
Delivery of proteins into living cells, such as genome-editing nucleases, active inhibitory antibodies, or stimulatory transcription factors, represents a powerful toolset for manipulating and analyzing cell function. Furthermore, effective intracellular delivery could expand the repertoire of usable protein drugs as most current protein-based therapeutics hit extracellular targets and this is a frontier of current research efforts.
Delivery of purified proteins into cells began as early as the 1960s. Examples include amoeba microinjected with ferritin and mouse eggs microinjected with bovine albumin. Because proteins have diverse size, shape and charge, they cannot easily be delivered into cells with one-size-fits-all solutions that cationic lipids use for nucleic acid transfection. In contrast, a diverse range of methods have been used to deliver proteins into cells including: microinjection, osmotic lysis of pinosomes, hypotonic shock, scrape loading, bead loading, syringe loading, detergent exposure, electroporation, pore-forming toxins, cell penetrating peptides, nanocarriers, cell squeezing, nanoneedles, acoustic perturbations, and vapor nanobubbles. For the purposes of genome editing, Cas9 protein combined with sgRNA has been delivered by methods ranging from electroporation, microinjection, lipid nanoparticle formulations, osmotically induced endocytosis followed by endosome disruption, microfluidic deformation, and cell penetrating peptides among others.
Small Molecules
Small molecules requiring intracellular delivery include:
impermeable small molecule drugs,
small molecule probes, and
cryoprotectants.
An example of the former is bleomycin, an anticancer drug with poor permeability due to its positive charge and hydrophobicity. By performing intracellular delivery with electroporation, bleomycin potency can be increased more than a hundred-fold. As for small molecule probes, when delivered to the cell interior, these molecules are capable of reporting cellular properties such as membrane potential, pH, and concentrations of ions. One example is PFBI, a fluorescent dye that can be employed for measurement of intracellular potassium concentration. Finally, some candidate cryoprotectant molecules such as impermeable sugars are highly hydrophilic and do not ready diffuse across cell membranes. For example, trehalose (Mw = 342 Da) is a natural disaccharide synthesized by a range of organisms to help them withstand desiccation or freezing. Trehalose loaded into animal cells at concentrations up to 200 mM has been shown to provide excellent cryoprotection during freezing and thawing.
Microscale Cargo
Cargo materials in the microscale have been successfully delivered into cells for a variety of applications. For a century microinjection has been the dominant method for introducing microscale cargo into cells. A classic example was the transplant of a somatic cell nucleus into a frog egg to demonstrate that nuclei from fully differentiated somatic cells could grow into a new animal when inserted into an egg. Microinjection was first used to inject sperm into eggs as a proof of concept for IVF in animals. Artificial chromosomes have been engineered and transferred into cells by microinjection for proof-of-concept gene therapy. Transplant of mitochondria has also been demonstrated in several cell types via microinjection. More recently laser-triggered cavitation bubbles have been used to open transient holes in the cell membrane for the purpose of delivering bacteria and mitochondria. Using microinjection or ballistic propulsion, micron-scale particles, spheres, and beads have been loaded into cells for cellular microrheology studies that assess internal mechanical behavior of cells. For example, using microinjected PEGylated tracer beads of up to 5.6 micron, it was shown that motor-driven cytoplasmic mixing substantially enhanced intracellular movement of both small and large cellular components.
Others
Other materials of interest for intracellular delivery include carbon nanotubes, quantum dots, magnetic nanoparticles, and nanodevices that serve as sensors or probes
Medical Applications
The following are examples of medical treatments that rely on intracellular delivery in at least one step.
Hematopoietic stem cell-based gene therapies:
Strimvelis for the treatment of adenosine deaminase severe combined immunodeficiency (ADA-SCID), produced through ex vivo gamma retroviral vector gene delivery of a functional adenosine deaminase (ADA) gene (European approval granted 2017). Strimvelis was the first ex vivo autologous gene therapy to gain approval from the European Medicines Agency.
Atidarsagene autotemcel (branded as Libmeldy) for the treatment of metachromatic leukodystrophy (MLD), produced through ex vivo lentiviral gene delivery of a functional human arylsulfatase A (ARSA) gene (European approval granted 2020).
Betibeglogene autotemcel (branded as Zynteglo) for the treatment of transfusion-dependent beta thalassemia (TDT), produced through ex vivo lentiviral gene delivery of a functional human HBB gene (European and US approvals granted 2022).
CAR-T cell immunotherapies:
Tisagenlecleucel (branded as Kymriah) for the treatment of B-cell acute lymphoblastic leukemia (B-Cell ALL), produced through ex vivo lentiviral gene delivery of a CAR gene targeting CD-19 (US approval granted 2017).
Axicabtagene Ciloleucel (branded as Yescarta) for the treatment of large B-cell lymphoma, produced through ex vivo gamma retroviral gene delivery of a CAR gene targeting CD-19 (US approval granted 2017).
Brexucabtagene Autoleucel (branded as Tecartus) for the treatment of adult patients with relapsed/refractory mantle cell lymphoma (r/r MCL), produced through ex vivo gamma retroviral gene delivery of a CAR gene targeting CD-19 (US approval granted 2021).
In vivo viral vector-mediated gene therapy:
Onasemnogene Abeparvovec (branded as Zolgesma) for the treatment of spinal muscular atrophy, administered by intravenous infusion of a AAV9 viral vector that delivers a functional SMN1 transgene to the affected motor neurons (US approval granted 2019).
Voretigene neparvovec (branded as Luxturna) for the treatment of Leber congenital amaurosis (an inherited retinal disorder causing progressive blindness), administered by subretinal injection of a AAV2 viral vector that delivers a functional copy of the RPE65 gene to eye cells to compensate for the RPE65 mutation (US approval granted 2017).
siRNA medicines:
Patisiran (Onpattro) for the treatment of polyneuropathy in people with hereditary transthyretin-mediated amyloidosis, administered by intravenous infusion of siRNA formulated into lipid nanoparticles that gain entry into liver cells to silence the expression of pathogenic transthyretin mRNA (US and European approval granted 2018).
Givosiran (Givlaari) for the treatment of adults with acute hepatic porphyria, administered by administered by intravenous infusion of siRNA-GalNAc conjugates that gain entry into liver hepatocytes to silence the expression of pathogenic aminolevulinate synthase 1 (ALAS1) mRNA (US approval granted 2019).
mRNA vaccines:
Moderna COVID-19 Vaccine (branded as Spikevax) designed to provide protection against COVID-19 caused by infection with the SARS-CoV-2 virus (US emergency use authorization 2020). It is administered by intramuscular injection of 0.5 mL doses of mRNA-LNP complexes in saline. Local injection has been reported to deliver mRNA-LNP complexes to resident/infiltrating APCs, related immune cells, and muscle cells, stimulating local expression
of covid spike protein to prime the immune system against future exposure to SARS-CoV-2.
Pfizer-BioNTech COVID-19 Vaccine (branded as Comirnaty) designed to provide protection against COVID-19 caused by infection with the SARS-CoV-2 virus (US emergency use authorization 2020). The mechanism is the same as Moderna (above) except that composition of the lipid nanoparticles are different, with Pfizer using the ionizable lipid known as ALC-0315 while Moderna uses an ionizable lipid called SM-102.
Antisense oligonucleotides (ASOs):
Mipomersen (branded as Kynamro), for the treatment of homozygous familial hypercholesterolaemia, administered by subcutaneous injection of chemically modified ASOs that accumulate into the liver with a half-life of ~30 days.
The ASOs gain entry into liver cells to prevent the expression of pathogenic ApoB mRNA (US approval granted 2013).
Spinraza (branded as Nusinersen) for the treatment of Spinal Muscular Atrophy (SMA), administered by intrathecal injection of chemically modified ASOs that enter motor neuron cells, bind SMN2 mRNA, and alter the alternative splicing of the SMN2 gene to restore expression of the protein.
In vitro fertilisation (IVF) for human pregnancies:
In cases such as low sperm count or motility, or where eggs cannot easily be penetrated by sperm, single sperm may be microinjected directly into the egg using a procedure termed intracytoplasmic sperm injection (ICSI). After injection the fertilised egg is incubated in a special growth medium for about 48 hours until the egg consists of six to eight cells. It is then transferred to the patient's uterus through a thin, plastic catheter, which goes through the vagina and cervix. The first human pregnancy generated by ICSI was carried out in 1991 by Gianpiero Palermo and his team. IVF through ICSI has facilitated millions of pregnancies worldwide since the 1990s.
Safety. Research is still in the early stages of understanding the immediate and long-term medical effects of intracellular delivery of materials to human cells. For example, investigations have shown that children born through ICSI suffer more health problems than those naturally conceived. However, it is not known whether this is due to poorer health of the parents reproductive systems or aspects of the IVF and ICSI procedure. HSC-based gene therapies prepared with gamma retroviral and lentiviral vectors have in some cases shown an increased risk of leukemia down the track due to genotoxicity, as occurred with Strimvelis. Furthermore, the lipids used for intracellular delivery of therapeutic siRNA and mRNA may cause inflammatory reactions. In the case of patisiran, pretreatment with multiple anti-inflammatory drugs is used to minimize reactions to the nanoparticle. There is currently little data available on the medical impact of intracellular delivery of novel chemical components of mRNA vaccines, such as SM-102 and ALC-0315, on both the short and long-term health of the recipient population. Thus, safety and unintended side-effects will continue to be a topic of importance for medical treatments that utilize intracellular delivery.
Categories of Methods
Current methods of intracellular delivery can be placed into two broad categories:
Membrane disruption-mediated
Carrier-mediated
Membrane Disruption
Membrane disruption-mediated techniques involve creating temporary holes in the cell membrane and delivering the cargo molecules via either
A) Permeabilization and diffusive influx of materials from the extracellular solution
B) Direct penetration with a vehicle or carrier that both punctures the plasma membrane and introduces the cargo of interest.
The plasma membrane of the cell can be disrupted through mechanical, electrical, chemical, optical or thermal means. Intracellular delivery methods that employ permeabilization include:
Electroporation
Thermal treatments
Optoporation (usually with a laser)
Cavitation effects (usually from ultrasound or laser/particle interactions)
Fluid shear (usually via microfluidics or cavitation)
Detergents/Surfactants
Pore-forming toxins
Osmotic/hydrostatic forces
Direct mechanical methods like microfluidic cell squeezing, scrape loading, bead loading.
Intracellular delivery methods that utilize direct penetration include:
Classic microinjection
Newer forms of microinjection (e.g. Nanopipette, Automation etc.)
Ballistic particles / Gene gun
Nanoneedles and their variations such as Nanostraws, Nanospears and Nanowires.
Membrane disruption-mediated delivery methods can deliver almost any material that can be dispersed in solution, making them more universal than carrier-mediated methods. The major challenge for membrane disruption-mediated methods is to create holes of the optimal shape, size, location, and duration for the required delivery application. Excessive membrane damage should be avoided as it can kill cells or impair their function.
Carriers
Carrier-mediated delivery techniques package the cargo into or onto a nanoscale carrier, which then enters the cell to deliver the cargo. Carriers generally gain entry to the cell interior via either
Endocytosis (the majority of carriers) or
Fusion with the cell's plasma membrane
However, there are rare reports of certain carriers crossing or transiently disrupting the plasma membrane through hitherto unknown mechanisms
.
Carrier-based approaches comprise various biochemical assemblies, mostly of molecular to nanoscale dimensions. The purpose of carriers is threefold,
to package the cargo and protect it from degradation,
to gain access to the intended intracellular compartment, and
to release the payload at the appropriate time and location.
Carriers can be bio-inspired, such as reconstituted viruses, virus like particles, vesicles, cell ghosts, and functional ligands and peptides. They may be based upon synthesis techniques from chemistry, materials science and nanotechnology, involving assembly of macromolecular complexes from organic and inorganic origins. Carriers that have been used for intracellular delivery include:
Polymer assemblies
Lipid assemblies
Liposomes (hollow with aqueous interior, unlike lipid assemblies)
Salt complexes (e.g. CaPO4-nucleic acid condensates)
Exosomes and other bio-inspired vesicles
Cell-penetrating peptides (CPPs), also known as protein transduction domains (PTDs)
Ligand conjugates
Protein or Sugar based nanoassemblies (e.g. Chitosan)
Inorganic nanocarriers (e.g. mesoporous silica, metal nanoparticles, magnetic nanoparticles)
Nanotechnology-based carriers (e.g. quantum dots, carbon nanotubes)
Viral vectors (based on lentivirus, retrovirus, adenovirus, adeno-associated virus(AAV), and other viruses)
Re-purposed bacterial toxins and viral components
Research into how carriers enter cells indicates that most carriers enter via endocytosis before escaping from endosomal compartments into the cytoplasm
.
Mechanisms of endocytosis available to nanocarriers include phagocytosis and pinocytosis through clathrin-dependent and clathrin-independent pathways
.
The internalization pathways employed by target cells depend on the size, shape, material composition, surface chemistry, and/or charge of the carrier
.
Cargo not able to escape endosomes are trafficked to lysosomes for degradation or recycled back to the cell surface
.
Efficiencies of around 1% endosomal escape have been reported for most non-viral carrier strategies, including lipid nanoparticles and cell-penetrating peptides
.
Moreover, the exact mechanisms of endosome escape remain unclear and are a matter of ongoing research
.
Apart from endocytosis, some carriers are able to directly merge with the plasma membrane through fusion. Fusion events in biology include vesicle fusion, cell–cell fusion and cell–virus fusion. In these cases, juxtaposed membranes are pulled into close contact by specific protein–protein interactions and interfacial water is excluded to promote lipid mixing and subsequent fusion. Enveloped viruses may employ transmembrane viral proteins to mediate fusion with target cell membranes and this mechanism has been exploited for engineered intracellular delivery
.
An early example was the use of sendai virus to fuse pre-loaded red blood cell ghosts with the plasma membrane of target cells
.
A variation on this technique utilized expression of influenza hemagglutinin (HA) at the target cell membrane, which then binds sialic acid residues on the red blood cell surface to induce fusion
.
Virosomes, which consist of viral membrane components reconstituted into liposomes or vesicles, also exhibit fusion capabilities for the purposes of intracellular delivery. Functional virosomes have been constructed with fusion components from sendai, influenza, vesicular stomatitis and other viruses
.
Some exosomes and extracellular vesicles have been reported to fuse with target cells
and may furthermore be engineering to fuse on demand
.
Interestingly, fusogenic liposomes used for protein delivery have been reported to be capable of fusion by modulating only the lipid composition without any need for the presence of fusogenic proteins or peptides
.
Fusogenic carriers that have been used for intracellular delivery include
(1) cell ghosts, dead cells that have had their cytoplasm replaced with cargo,
(2) virosomes, cargo-loaded vesicles reconstituted to display functional viral proteins, and
(3) fusogenic liposomes.
Viral vectors. Viral vectors exploit the viral infection pathway to enter cells but avoid the subsequent expression of viral genes that leads to replication and pathogenicity. This is done by deleting coding regions of the viral genome and replacing them with the DNA to be delivered, which either integrates into host chromosomal DNA or exists as an episomal vector. Viral vectors were first employed for gene delivery from the 1970s, constructed from SV40
or retroviruses
.
Newer generations of viral vector platforms have been produced based on components from lentivirus, retrovirus, adenovirus or adeno-associated virus, and other viruses
.
While highly efficient for DNA delivery, notable weaknesses of viral vectors are (1) labor-intensive and expensive protocols, (2) safety issues, (3) risk of causing immune/ inflammatory responses, (4) integration into the genome with recombinant vectors, (5) risk of insertional genotoxicity, and (6) limited packaging capacity (Adeno and AAV typically restricted to carry 5−7.5 kb).
Nanoparticles for transfection. The most commonly used nanoparticles for intracellular delivery of nucleic acids are based on assemblies of cationic lipids and polymers. These cationic molecules condense DNA plasmids (~50-200 nm), mRNA (10-100 nm) and other nucleic acids (see "Properties of common molecules of interest for intracellular delivery") into compact nanoparticles with dimensions down to tens of nanometers. The positive charge of these particles facilitates their attraction to the cell surface due to the natural negative charge of most animal cells (−35 to −80 mV membrane potential). Upon binding, endocytosis is thought to be most efficient for particles in the size range below 100 nm
.
Complexation into nanoparticles also confers protection for nucleic acids against degradation until they are released to the appropriate intracellular compartment
.
From the 1960s it was observed that mixing nucleic acids with cationic molecules leads to the formation of macromolecular complexes that can transfect cells. Two early examples were the polymer diethylaminoethyl-dextran(DEAE-dextran)/nucleic acid combination (1968)
and the insoluble ionic salt calcium phosphate/nucleic acid precipitant (1973)
.
The use of cationic lipids for transfection began in the 1980s
, was termed "lipofection", and became the basis for the popular product lipofectamine launched in 1993. Other cationic transfection reagents were developed in the 1990s based on dendrimers such as PAMAM
in 1993 (“superfect” reagent launched in late 1990s) and cationic polymers such as PEI in 1995
(marketed as “polyjet” soon after). Currently in research, most nucleic acid transfection is performed with lipid reagents, with polymer reagents and electroporation as other major options. Certain recalcitrant cells or in vivo applications may be better suited for viral vectors
.
Technical Advances
Improving Precision of Membrane Disruption
Advancements in microfabrication, nanotechnology, chemistry and other research fields have contributed to the improvements in precision and performance of intracellular delivery methods
.
Electroporation.
Early versions of electroporation used bulk electrodes to apply electrical pulses of defined voltage to cells in solution in a cuvette
.
Electroporation was then brought down to the microscale through the use of microfluidics in the late 90s
. Following that nano-electroporation was achieved through the use of nanoapertures and nanostraws.
The nano and micro versions of electroporation feature much higher precision and control over the size and location of membrane disruptions imposed on target cells
.
A company called Maxcyte has developed a high-throughput version of flow electroporation that can process hundreds of millions of cells in tens of minutes
.
Furthermore, other research groups have employed deep learning to improve electroporation parameters in high throughput multi-well systems
.
Mechanical Contact.
The first versions of intracellular delivery protocols exploiting the mechanical force of objects striking the cell membrane were simple and crude methods such as scrape loading and glass bead loading
.
In scrape loading, for example, a spatula is dragged across adherent cells that have been cultured on a flat substrate. As the cells peel off the substrate they undergo a variable amount of membrane damage and are able to take up molecules in solution. Scrape and bead loading have been used in many biological studies to introduce proteins and small molecules into cells
.
Since the late 1990s researchers have worked to improve the precision of solid contract-based membrane disruption through the use of nanoneedles and microfabricated devices
.
Nanoneedles were first used for nucleic acid transfection in 2003
then demonstrated delivery of diverse cargoes in 2010
.
They have been combined with electroporation, flow reservoirs, and detergents to add more functionality
.
Moreover, nanostraws have been used to both insert and extract molecules into cells in a time-resolved manner
.
In 1999 it was found that passing cells through holes in polycarbonate filters created temporary disruptions in the cell membrane to achieve DNA transfection
.
The method was termed "filtroporation" and did not receive much attention at the time. In 2012 researchers at MIT found that passing cells through constrictions in silicon microfluidic devices was capable of disrupting the cell membrane to achieve intracellular delivery of diverse materials
.
The method, termed cell squeezing, was spun out into a company called SQZ biotech that focuses on leveraging intracellular delivery technology to develop cell-based therapies. By adjusting the flow speed of cells and the shape and size of microfluidic constriction, cell squeezing can be tailored for different cell types and delivery applications. Other research groups have demonstrated the cell squeezing concept in microsieves and PDMS-based microfluidic devices
.
Cell squeezing has been combined with electroporation to achieve rapid delivery of DNA and other materials into the nucleus
. This works by first introducing holes into the plasma membrane, then having an electrical pulse serve to 1) disrupt the nuclear membrane, and 2) drive negatively charged nucleic acids into the cell
.
Microfluidic cell squeezing followed by downstream electroporation has been shown to cause temporary disruptions in nuclear membrane that were repaired within 15 minutes
.
Fluid Shear.
Early examples of using fluid shear forces to controllably disrupt the cell membrane include conventional ultrasound
, syringe loading for cells in suspension
and the use of cone-plate viscometers on adherent cells
.
In syringe loading, suspensions of cells are sucked and expelled from a syringe through a fine needle tip. The fluid shear forces at the tip of the needle depend upon the flow velocity and can be tailored to disrupt the cell membrane. Since the 1990s, more precise strategies to employ fluid shear forces to permeabilize cells include microfluidics, ultrasound, shock waves, and laser-based methods
.
Laser irradiance of an absorbent object in an aqueous environment can produce a variety of effects including cavitation, plasma production, chemical reactions, and heat
.
Both laser-particle and laser-surface interactions have been exploited to create cavitation events that expose cells to locally concentrated fluid shear forces. For example, a metallic nanostructure can be used as a seed structure to harvest short laser pulse energy and convert it into highly localized explosive vapor bubbles. A high throughput version of this concept was unveiled in 2015
Substrates arrayed with pores lined by metallic absorbers were irradiated to generate exploding cavitation bubbles underneath the basal side of adherent cells. Membrane permeabilization was synchronized with active pumping of cargo through the pores to successfully introduce living bacteria (>1 micron) into the cytoplasm of several cell types.
Thermal Effects.
A simple way of delivering molecules into cells is to heat the plasma membrane until holes form. At sufficiently high temperatures, lipid bilayers will dissociate due to kinetic energy of the constituent molecules being greater than the forces that maintain the membrane formation, namely the hydrophobic forces that repel water from the lipid tails.
The downside of this method is that it is incredibly non-specific and may cause excessive harm to cells. Strategies for permeabilizing cells by thermal means include (1) cycling cells through a cooling−heating cycle, which may or may not involve freezing, (2) heating cells to supraphysiological temperatures, and (3) transient intense heating of a small part of the cell.
In the latter case, thermal inkjet printers have been successfully used for intracellular delivery and transfection in animal cells.
Laser-particle interactions have been reported to precisely thermally disrupt cell membranes. Gold nanoparticles were packed into a dense surface layer where >10 s of infrared laser irradiation heats the underside of cells to trigger permeabilization and delivery of dyes, dextrans and plasmids.
In 2021 this concept was developed further when researchers showed that light-sensitive iron oxide nanoparticles embedded in biocompatible electrospun nanofibres can trigger membrane permeabilization by photothermal effects without direct contact between cells and nanoparticles
.
This method was capable of delivering CRISPR–Cas9 machinery and siRNA to adherent and suspension cells, including embryonic stem cells and hard-to-transfect T cells.
Biochemical Enhancement of Cargo and Carriers
mRNA medicines.
Advances in lipid nanoparticle formulation and nucleic acid chemistry have been critical in the development of nucleic acid therapeutics, such as mRNA vaccines. For example, design of the cationic ionizable lipids, which are a key component of lipid nanoparticle formulations, with an acid dissociation constant (pKa) close to the early endosomal pH enable endosomal release into the cytoplasm after endocytosis
.
In the Moderna covid vaccine lipid nanoparticles are composed of ionizable lipid SM-102, cholesterol, 1,2-distearoyl-snglycero-3 phosphocholine (DSPC) and PEG2000-DMG to encapsulate mRNA. The Pfizer/BioNTech covid vaccines employ ALC-0315 lipid from Acuitas Therapeutics and formulate it with cholesterol, DSPC, and a PEG-Lipid (ALC-0159) together with mRNA
.
After intramuscular injection, the nanoparticles enter cells, mRNA is released into the cytoplasm, and the expression of SARS-CoV2 spike protein occurs in patient cells.
siRNA Medicines.
patisiran, the first siRNA based medicine to receive regulatory approval from the FDA in 2018, is based on lipid nanoparticle formulations that package and delivery siRNA to the liver for the silencing of an abnormal pathogenic form of transthyretin gene. The therapeutic siRNA is formulated with 2 lipid excipients, DLin-MC3-DMA and PEG2000-C-DMG, in a lipid nanoparticle that is intravenously infused into the patient and targets hepatocytes in the liver. Moreover, Chemically modified nucleotides in siRNA therapeutics improve chemical stability and efficacy, assist in targeting certain cell types, and serve to reduce adverse immunological reactions
.
Diverse ligands including small molecules, carbohydrates, aptamers, peptides and antibodies have been covalently linked to siRNA in order to improve cellular uptake and target specific cell types. For example, GalNAc-siRNA conjugates not only provide an approach for ligand based cell internalization without the need of cationic materials, but also target hepatocytes specifically
. GalNAc-siRNA conjugates were employed in the second FDA-approved siRNA medicine, Givosiran, which is administered to treat acute Hepatic Porphyria by down-regulating ALAS1 expression in the liver.
ASO Medicines.
The first approved antisense oligonucleotides (ASO) medication was unveiled in 1998 with fomivirsen, a 21-mer oligonucleotide that blocks the translation of cytomegalovirus mRNA
.
By binding pre-mRNA or mRNA, ASOs can post-transcriptionally regulate protein synthesis through mechanisms including modification of pre-mRNA processing and splicing, competitive inhibition, steric blockade of translational machinery, and degradation of bound target RNA
.
Chemical modifications of ASO nucleosides, nucleobases, and the internucleoside backbone are key for improving pharmacokinetics and pharmacodynamics while maintaining target affinity and efficacy. Therapeutically effective ASOs are heavily modified, so they do not require a carrier for intracellular delivery. Most medically applicable ASOs are naked molecules that are able to enter cells through endocytosis and exert their therapeutic effects by binding their intracellular target
.
Improved Viral Vectors.
Nearly 70% of gene therapy clinical trials have utilized viral vectors for the gene delivery step
.
Adenovirus, Adeno-associated virus (AAV) and lentiviral vectors are currently the main viral vectors used in biotechnology and clinical applications
.
AAV is as a prominent example of improvements made in viral vectors. Vector engineering can increase AAV transduction efficiency (by optimizing the transgene cassette), vector tropism (using capsid engineering) and the ability of the capsid and transgene to avoid the host immune response (by genetically modifying these components), as well as optimize the large-scale production of AAV
Moreover, vector engineering approaches including directed evolution have greatly enhanced the efficiency and targeting of AAV vectors, resulting in >100-fold improvement in delivery efficiency in some cases.
In another example of AAV engineering, machine learning has been applied to generate AAV variants that can circumvent immune responses from previous exposure
.
Virus-like Particles.
Virus-like particles (VLPs) are assemblies of viral proteins that package cargo materials such as mRNAs, proteins, or RNPs in addition to, or instead of, viral genetic material. Because VLPs are derived from existing viral scaffolds, they exploit natural properties of viruses that enable efficient intracellular delivery, including their ability to encapsulate cargos, escape endosomes, and be reprogrammed to target different cell types. However, unlike viruses, VLPs can deliver their cargo as mRNA or protein instead of as DNA, which substantially reduces the risks of viral genome integration. VLPs are thus of interest for delivering molecular cargo such as gene editing agents as they can offer benefits of both viral and non-viral delivery
.
Engineered DNA-free VLPs have recently been shown to efficiently package and deliver base editor or Cas9 ribonucleoproteins to mammalian cells for the purpose of gene editing
It was reported that delivery of gene editing proteins with VLPs offered substantially minimized off-target editing compared with plasmid and viral delivery in vitro.
References
Gene delivery
Biotechnology | Intracellular delivery | [
"Chemistry",
"Biology"
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"Biotechnology",
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71,615,931 | https://en.wikipedia.org/wiki/Erythrohydrobupropion | Erythrohydrobupropion (developmental codes BW 287, BW 17U) is a substituted amphetamine derivative—specifically a β-hydroxyamphetamine—and a minor active metabolite of the antidepressant drug bupropion (Wellbutrin). Bupropion is a norepinephrine–dopamine reuptake inhibitor and nicotinic acetylcholine receptor negative allosteric modulator, with its metabolites contributing substantially to its activities. Erythrohydrobupropion exists as a racemic mixture of two stereoisomers, (1R,2S)-erythrohydrobupropion and (1S,2R)-erythrohydrobupropion. Other metabolites of bupropion include hydroxybupropion and threohydrobupropion.
Information on the pharmacological actions of erythrohydrobupropion is scarce. In any case, it is about 20% as pharmacologically potent as bupropion and in the range of 20 to 50% as potent as bupropion in mouse models of depression. It circulates at similar concentrations as bupropion during bupropion therapy. Conversely, two other metabolites, hydroxybupropion and threohydrobupropion, circulate at higher concentrations than bupropion.
Erythrohydrobupropion is formed from bupropion via reduction of the ketone group primarily by 11β-hydroxysteroid dehydrogenase-1 and to a minor extent by aldo-keto reductases. It can also be formed from bupropion by carbonyl reductases. The compound is metabolized by the cytochrome P450 enzymes CYP2B6 and CYP2C19 into erythro-4'-hydroxy-hydrobupropion and by various glucuronosyltransferase enzymes into glucuronide conjugates. The elimination half-life of erythrohydrobupropion is approximately 33hours. Its half-life may be longer in older people.
Insomnia during bupropion therapy has been associated with erythrohydrobupropion concentrations. Administration of erythrohydrobupropion in mice produces seizures at sufficiently high doses similarly to bupropion and other metabolites. Erythrohydrobupropion is a CYP2D6 inhibitor and accounts for about 9% of CYP2D6 inhibition during bupropion therapy, with hydroxybupropion accounting for 65% and threohydrobupropion accounting for 21%.
References
Antidepressants
Beta-Hydroxyamphetamines
2-Chlorophenyl compounds
Convulsants
Human drug metabolites
Phenethylamines
Tert-butyl compounds | Erythrohydrobupropion | [
"Chemistry"
] | 657 | [
"Chemicals in medicine",
"Human drug metabolites"
] |
71,616,083 | https://en.wikipedia.org/wiki/TOI-1452%20b | TOI-1452 b is a confirmed super-Earth exoplanet, possibly a water world, orbiting a red-dwarf star TOI-1452 about 100 light-years away in the Draco constellation. The exoplanet is about 70% larger in diameter than Earth, and roughly five times as massive.
System
The TOI-1452 star system is 99 light-years away from Earth, located in the constellation of Draco. It is a binary pair of dim red dwarf stars separated by only 96 astronomical units (AU). A notable feature of this system is the presence of an exoplanet around one of the stars, designated as TOI-1452 b. It is two M4 dwarf stars that were observed by TESS as a priority, since they are on the cool dwarf list, a list of high-priority orange-red and red dwarf stars, that was uploaded to TESS. It is a flare star, with a flare observed by TESS where the star brightened by 5%. The secondary star is often distinguished from the first with the name "TOI-1760".
Discovery
TOI-1452 b was discovered by an international team led by astronomers from the Université de Montréal, using data from NASA’s Transiting Exoplanet Survey Satellite (TESS). The discovery was first reported in June 2022.
References
Draco (constellation)
Exoplanets discovered in 2022
Super-Earths
Transiting exoplanets
Exoplanets discovered by TESS
Super-Earths in the habitable zone
Extraterrestrial water
Giant planets in the habitable zone
Near-Earth-sized exoplanets in the habitable zone | TOI-1452 b | [
"Astronomy"
] | 345 | [
"Constellations",
"Draco (constellation)"
] |
71,616,399 | https://en.wikipedia.org/wiki/Vegeta%20%28software%29 | Vegeta is an HTTP load testing tool written in Go that can be used as a command in a command-line interface or as a library. The program tests how an HTTP-based application behaves when multiple users access it at the same time by generating a background load of GET requests. Vegeta is used to generate a sustained, constant number of requests per second in order to discover how long a service can sustain a peak load before dropping in performance.
In addition to preemptive load testing, the program can also be used for shadow testing, where traffic from a live version of an application is mirrored onto a test version to determine how it handles the same traffic load, without causing potential disruption to the live version of the application. Shadow testing is done in this way in order to analyze anticipated server performance.
Vegeta is provided for use by web hosting services such as Scaleway to use varied and multiple requests to stress test client HTTP services. It is also used with dedicated load-testing platform services such as BlazeMeter.
Usage
The command-line usage is in the format of . The three global flags are which specifies the number of CPUs to use, which enables profiling, and which prints the software version and then terminates the program.
The commands available are , , , and , each with its own various command flag options, and both attack input and report output can be done in an optional JSON format when specified with the appropriate flag.
Vegeta can specify targets as URLs in a separate file with optional custom headers and requests, which can then be used as an input option on the command line.
Example
An example usage would be to issue from the command-line. This example uses the echo command to output , and then executes the attack command for that output for five seconds. After that, it uses the tee command to write results to a file called results.bin, and runs the report command to display the output of the attack results.
References
Software testing
Quality assurance
Load testing tools
Linux software
Command-line software
Software using the MIT license | Vegeta (software) | [
"Technology",
"Engineering"
] | 419 | [
"Command-line software",
"Computing commands",
"Software engineering",
"Software testing"
] |
71,616,465 | https://en.wikipedia.org/wiki/Threohydrobupropion | Threohydrobupropion (developmental code names BW 494, BW A494U) is a substituted amphetamine derivative—specifically a β-hydroxyamphetamine—and a major active metabolite of the antidepressant drug bupropion (Wellbutrin). Bupropion is a norepinephrine–dopamine reuptake inhibitor and nicotinic acetylcholine receptor negative allosteric modulator, with its metabolites contributing substantially to its activities.
Chemistry
Threohydrobupropion exists as a racemic mixture of two stereoisomers, (1R,2R)-threohydrobupropion and (1S,2S)-threohydrobupropion. Other metabolites of bupropion include hydroxybupropion and erythrohydrobupropion.
Pharmacology
Information on the pharmacological actions of threohydrobupropion is scarce. In any case, it is about 20% as pharmacologically potent as bupropion and in the range of 20 to 50% as potent as bupropion in mouse models of depression. Moreover, threohydrobupropion has been reported to weakly inhibit the reuptake of norepinephrine, dopamine, and serotonin with rat or Ki values of 16μM, 47μM, and 67μM, respectively. These values can be compared to rat values with bupropion of 1,400nM, 570nM, and 19,000nM, respectively. Besides monoamine reuptake inhibition, threohydrobupropion has also been reported to inhibit α3β4 nicotinic acetylcholine receptors, with an IC50 value of 14μM. Threohydrobupropion circulates at higher concentrations than bupropion during bupropion therapy, similarly to hydroxybupropion but in contrast to erythrohydrobupropion—which circulates at similar concentrations as bupropion.
The plasma protein binding of threohydrobupropion is 42%. Threohydrobupropion is formed from bupropion via reduction of the ketone group by 11β-hydroxysteroid dehydrogenase-1 and aldo-keto reductases. It can also be formed from bupropion by carbonyl reductases. The compound is metabolized by the cytochrome P450 enzymes CYP2B6 and CYP2C19 into threo-4'-hydroxy-hydrobupropion and by various glucuronosyltransferase enzymes into glucuronide conjugates. Its elimination half-life is approximately 37hours.
Dry mouth during bupropion therapy has been associated with threohydrobupropion concentrations. Administration of threohydrobupropion in mice produces seizures at sufficiently high doses similarly to bupropion and other metabolites. Threohydrobupropion is a CYP2D6 inhibitor and accounts for about 21% of CYP2D6 inhibition during bupropion therapy, with hydroxybupropion accounting for 65% and erythrohydrobupropion accounting for 9%.
References
Antidepressants
Beta-Hydroxyamphetamines
3-Chlorophenyl compounds
Convulsants
Human drug metabolites
Nicotinic antagonists
Secondary alcohols
Secondary amines
Serotonin–norepinephrine–dopamine reuptake inhibitors
Tert-butyl compounds | Threohydrobupropion | [
"Chemistry"
] | 814 | [
"Chemicals in medicine",
"Human drug metabolites"
] |
71,617,444 | https://en.wikipedia.org/wiki/Noida%20Supertech%20Twin%20Towers | The Apex Tower and Ceyane Tower, colloquially referred to as the Noida Supertech Twin Towers, were incomplete residential buildings in Sector-93A, Noida, Uttar Pradesh, India. The towers were part of real estate company Supertech Limited's Emerald Court residential complex. The Supreme Court of India upheld the original decision by the Allahabad High Court and ordered the buildings' demolition on 28 August 2022. They were the tallest structures in India to be voluntarily demolished.
History
On 23 November 2004, the New Okhla Industrial Development Authority (NOIDA Authority) allotted M/s Supertech Limited, a plot of land measuring 48,263 square metre (11.92 Acre) in Sector-93A. The plan for the Emerald Court residential complex in Noida came into inception in June 2005. The original plan according to plans submitted by the NOIDA Authority in the city, called for Emerald Court to have 14 buildings and included 3, 4 and 5 BHK flats.
It was in 2009, that plans for the twin towers, Apex and Ceyane, were added to the Emerald Court development. There were originally conceived as 24-storey structures to be built on a triangular site originally allotted for a green area.
Supertech modified their plan for a third time in March 2012. By that time the plan for Emerald Court was revised to include 15 buildings instead of 14, the number of floors for each building was increased to eleven from nine The twin towers' height were increased from 20 to 40.
Legal case
The legal dispute began in 2009 when four residents raised concern regarding Supertech Limited's violation of building by-laws by building the twin towers. The core team of Emerald Court Owner Residents Welfare Association (ECO RWA) included Uday Bhan Singh Teotia (ex- DIG of CRPF), SK Sharma, Ravi Bajaj, and MK Jain.
Shortly after, in 2010, the builder started digging up more areas, where a shopping complex and garden had been planned. They then found out that the builder was planning two new 40-floor towers in that area – Apex and Ceyanne. The legal expenses amounted to almost Rs 1 crore (Rs 10 million). MK Jain, who passed away in 2021 due to COVID, led the team and raised money.
In mid-2012, residents of Emerald Court filed a case before the Allahabad High Court seeking for the demolition of the twin towers. In April 2014, the high court ruled in favor of the residents. The matter reached to the Supreme Court of India, which upheld the Allahabad High Court decision on August 31, 2021. The construction of the towers violated India's National Building Code, 2005 (NBC).
The Forum For People's Collective Efforts (FPCE), hailed the decision as a landmark ruling in the history of India's real estate industry and mentioned that the case should serve as a deterrent against illegal construction. The Supreme Court directed that all home buyers be refunded with 12% interest rate. They also awarded the Emerald Court RWA to be paid Rs 2 crores.
Demolition
The Supreme Court originally set 21 August 2022 as the deadline for the Supertech Twin Towers' demolition. However this was extended by a week to 28 August, and a buffer period (29 August to 4 September) was given as a contingency for any marginal delay due to weather conditions. The Noida authority and Roorkee-based Central Building Research Institute (CBRI) tasked Edifice Engineering and South African firm Jet Demolition to demolish the buildings. The buildings were brought down through implosion.
The blast took place on 28 August 2022 at around 2:30 pm. An estimated 3,700 kilograms of explosives were poured into more than 9,000 holes in the structures.
On 28 August 2022 at 2:30 pm, the towers were demolished after the implosion in about 10 seconds. Around 10,000 people watched the implosion. This was the first time when a building with more than 30 storeys has been demolished in India.
Impact on the environment
Experts were concerned about the birds in the area of the demolition and dust pollution due to the debris. The Air quality index (AQI) before and just after the demolition was 108 and 676 respectively.
Operation
This was the biggest operation and demolition ever done in India as this structure was higher than Qutb Minar (72.5 metres). 9640 drill holes were made in the columns of both the towers and more than 3,700 kg of explosives were used for the demolition.
Architecture and design
The Noida Supertech Twin Towers consisted of two buildings, Apex and Ceyane Towers. They were planned to have 40 floors each. The two structures had different heights. Apex had 32 floors and stood at tall while Ceyane had 29 floors and stood at . Both towers were intended to have 915 flats, 21 commercial shops, and two basements.
Timeline
Nov 2004: The NOIDA Authority allots plot of land for the construction of apartment.
Nov 2009: Construction work is started by the builder Supertech Limited.
Aug 2022: The Twin Towers are demolished on 28 August 2022 at 2:30 pm (IST).
References
Buildings and structures demolished by controlled implosion
Buildings and structures demolished in 2022
Buildings and structures in Noida
Former skyscrapers
Architectural controversies
Twin towers
Controversies in India
Unfinished buildings and structures
Unfinished buildings demolished | Noida Supertech Twin Towers | [
"Engineering"
] | 1,100 | [
"Buildings and structures demolished by controlled implosion",
"Architectural controversies",
"Architecture"
] |
71,617,761 | https://en.wikipedia.org/wiki/Abuse%20in%20gymnastics | A variety of forms of abuse have been reported in gymnastics, including physical, emotional, and sexual abuse. Abuse has been reported in multiple countries including Australia, Brazil, Canada, France, Portugal, the United Kingdom, and the United States.
Australia
The gymnastics community in Australia has been impacted by a long-standing history of abuse, and the failure of authorities to take appropriate action when concerns were raised leading to the protection of the abuse at a systemic level.
1995 - Opie report
In 1995, the Women's Artistic Gymnastics (WAG) program at the Australian Institute of Sport (AIS) faced accusations of abuse, with Coach Mark Calton being accused of hitting a 10 year old gymnast, with two other girls stating that their coach used emotional abuse calling them "fat" and "ugly". Within the same year, a former AIS gymnast filed a lawsuit against the Australian Sports Commission (ASC), alleging that the training regime at the AIS had caused her to suffer from anorexia nervosa, an eating disorder condition. As a result, Sports Minister John Faulkner commissioned an independent investigation to examine these allegations of physical and psychological abuse, conducted by sports lawyer, Hayden Opie.
This subsequent report, known as the Opie report, claimed that the physical assault of the 10 year old gymnast by her coach had resulted after the gymnast "provoked Calton into losing his self-control", but ultimately did not find he had struck her with Opie recommending counselling for the coach - not the gymnast - and dismissed the emotional abuse as the terms "fat" and "ugly" were often use in high-performance training centres such as the AIS environment. Ultimately, the Opie report concluded "No systematic or widespread abuse of AIS female gymnasts has been found to occur at any time. Major change at the AIS is not necessary.".
However, this inquiry has been criticised for being constrained by a narrow framework that did not address the broader issues present in the sport, resulting in the report providing recommendations that treated the symptoms rather than tackling the underlying problems and further legitimising and approving of the activities occurring that had upset parents and athletes. Critics also pointed out that "All parties involved in the sport of gymnastics had an interest in containing any perceived problems that might threaten the sport."
2003 - Geoffery Robert Dobbs trial and sentencing
In July 2003, gymnastics coach Geoffery Robert Dobbs was formally sentenced for life in jail with no prospect of parole on charges of molesting and producing child sexual abuse material of 62 girls aged from 12 months to 15 years old between 1972 and 1999. Detectives believed that in total, he may have abused more than 300 girls, leaving up to 240 alleged victims unaccounted for. His victims included athletes whom he had obtained access to through his role as a gymnastics coach.
2013 - Belooussov coach suspension
In 2021, the Australian Institute of Sport (AIS) responded to enquiries by the ABC to confirm the 2013 suspension of husband and wife coaches, Sasha and Olga Belooussov, for an 18-month period for the verbal abuse of a gymnast.
This suspension had remained unreported for eight years due to the complaint handling process by Gymnastics Australia (GA), which had meant that those involved, including the verbally abused gymnast and GA, were barred from speaking due to confidentiality provisions.
Despite this period of suspension, the Belooussov couple returned to coaching gymnastics in Australia, returning to their roles as personal coaches for Georgia Godwin (Australian Commonwealth Games and Olympian medalist), GA assistant coach, coaching at Queensland gymnastics club Delta Gymnastics, and winning the GA WAG International Coach/Coaching Team of the Year Award in 2019.
2018 - National Centre of Excellence investigation
During January 2018, the gymnastics world was exposed to the horrors of abuse in gymnastics as the Larry Nassar abuse trial played out publicly, raising awareness of child safety in sports, particularly within gymnastics, with victim Aly Raisman urging sporting bodies to ensure safeguards to ensure the mistakes of the United States were not repeated.
In response to the Larry Nassar case, Gymnastics Australia (GA) CEO Kitty Chiller made a statement regarding how the USA scandal had prompted GA to carry out an audit of their processes and policies, including an education process to empower "any young member or any member of a gymnastics association to know that they have a voice and to know where that voice will be heard." Kitty Chiller denied that GA had an existing problem with child abuse, stating "there's never been any evidence or complaints that anyone's been unhappy within the Gymnastics Australia environment" and GA's audit did not uncover any practices that needed to be changed.
However, within the same year, parents reported to Gymnastics Australia that their children as young as eight were being regularly verbally and physically abused at the GA National Centre of Excellence (NCE) in Melbourne.
In these complaints, parents alleged their children were punished via methods such as "making them swing on the bar until their hands bled, doing squats until their knees gave out, or making them do handstands and stay upside down until they felt sick and fell over" with punishments being given for any misdemeanour from being perceived as not paying attention or being cheeky to not performing to the coach's standards. Athletes were also allegedly regularly yelled at multiple times within a training session, and not being allowed to comfort one another, with training sessions being closed to parents despite medical appointments occurring during training sessions. ABC News confirmed 16 parents, with the majority of their children being under the age of 15 years old and spending between 20 and 33 hours a week training at the NCE.
When the parents took their complaints formally to GA, GA appointed an independent investigator in May. However, after receiving an interim report from the independent investigator, GA closed the investigation in August, with a letter from Kitty Chiller to the parents citing that the majority of allegations were "incomplete" and "based on the investigator's interim report, GA did not find that any staff member was in breach of their employment with GA". This letter also stated that "the investigation took longer than anticipated and an extension would likely increase the burden placed on all parties involved" with no fault or wrongdoing being concluded.
George Tatai, who spent 21 years on the GA board and eight years as a member of the International Gymnastics Federation, holding an Order of Australia Medal for his work in the sport, spoke out against the way that GA handled this investigation stating that they were paying lip-service to the parents' concerns and protecting GA ahead of the athletes.
One of the mothers then went on to make a formal complaint in 2020, using the newly formed GA independent complaints process, the "Supplementary Complaints Management Process" (SCMP), to allege that Kitty Chiller should not have closed this investigation as the CEO of Gymnastics Australia at the time. This 2020 complaint was then closed and never investigated, being deemed out of scope as the SCMP limited valid complaints to only those involving direct conduct towards an athlete, therefore excluding officials who may have handled historical complaints or had knowledge of abuse from investigation under this process.
However new information was discovered in 2022 in Senate Estimates that found that the SCMP was co-drafted by those within Kitty Chiller's office, with GA providing input into the policy's design instead of the process being fully independent.
When the SCMP policy was announced in 2020, Sport Integrity Australia (SIA) and the National Sports Tribunal (NST) had released a media statement confirming they would play a key role in the SCMP policy, with SIA facilitating an independent and comprehensive assessment of individual complaints and assisting with the management and coordination of investigation in accordance with assessor recommendations while NST planned to provide mediation, conciliation and tribunal hearings as needed.
With the release of this information within the Senate Estimates, ABC News began an investigation to explore who had made the decision to exclude officials from investigations under the SCMP, resulting in SIA, NST and GA all making conflicting statements to the ABC reporters. SIA stated that it was GA who was ultimately responsible for the SCMP, with the policy being developed by the NST for the board of GA to provide approval with SIA's input being only on sections relevant to their role. The NST statement stated that SCMP was a GA policy, and as such, GA was involved in its development up to board level, noting that both SIA and the NST assisted GA in its development. Meanwhile, however, GA distanced itself completely from the policy, stating that the policy " was developed by the NST, with input from SIA, in relation to their role in the process. This policy was endorsed by the Gymnastics Australia Board."
2020-2021 Gymnastics Australia abuse investigation
In 2020, the documentary film Athlete A was released, following investigative journalists as they broke the story of USA Gymnastics team doctor Larry Nassar sexually assaulting young female gymnasts, and the following allegations and trials around USA Gymnastics regarding the abuse they had suffered.
In the aftermath of the documentary release, dozens of Australian gymnasts took to social media to speak their own allegations of abuse within Australian gymnastics, exposing that the culture wasn't unique to gymnastics within the U.S. As a result, Gymnastics Australia (GA) announced an independent review into its own culture and practices, stating "those experiences are simply not acceptable." For this review, GA requested the Australian Human Rights Commission (AHRC) to act as the independent body to ensure the integrity of the review, with the report completed in 2021.
This report was undertaken by a dedicated team of AHRC staff, led by the Sex Discrimination Commission with input from the National Children's Commissioner, who all had expertise in responding sensitively in a trauma informed way to a range of issues such as sexual assault, sexual harassment and abuse. The original planned release date was within the first quarter of 2021, however due to the community interest in the review, AHRC extended the consultation timeline to allow more participation with the review.
Participation opened in September 2020, with all past and present members of the gymnastics community in Australia including athletes, coaches, staff, volunteers and administrators being encouraged to participate through a series of focus groups, interviews and written submissions. Policies and procedures were also reviewed, alongside the way these policies and procedures were implemented with the governance structures surrounding these.
During the undertaking of investigation, athletes spoke out about the abusive techniques used in gymnastics training to the media with lawyers forming groups to consider taking legal action, as the athletes stated that the Australian Institute of Sport (AIS) had ignored allegations of physical and psychological abuse for decades.
AHRC received 138 written submissions to the enquiry, with 47 interviews being conducted with 57 participants included current and former athletes, their families, staff, coaches and other relevant personnel.
AHRC launched the final version of the report on May 3, 2021. This report uncovered an environment where winning was focused on at all costs, normalising abuse due to the lack of understanding and prevention of the full range of child abuse and neglect behaviours in gymnastics, with a governance structure set up in an unsuitable manner for effective child safeguarding.
The five overarching key findings of the report were:
"Current coaching practices create a risk of abuse and harm to athletes. Additionally, hiring practices for coaching staff lack accountability and there are inconsistent policies and systems to regulate their behaviour."
"There is an insufficient focus on understanding and preventing the full range of behaviours that can constitute child abuse and neglect in gymnastics."
"A focus on ’winning-at-all-costs’ and an acceptance of negative and abusive coaching behaviours has resulted in the silencing of the athlete voice and an increased risk of abuse and harm with significant short and long-term impacts to gymnasts."
"There is an ongoing focus in gymnastics on the ‘ideal body’, especially for young female athletes. This, in addition to inappropriate and harmful weight management and body shaming practices, can result in the development of eating disorders and disordered eating which continue long after the athlete has left the sport."
"Gymnastics at all levels has not appropriately and adequately addressed complaints of abuse and harm and are not effectively safeguarding children and young people. Contributing factors include a lack of internal expertise and resources and complicated governance structures."
A total of 12 recommendations were also made as a result of this review, including:
"Transform education to skills development for coaches"
"Strengthen coach engagement and accountability"
"Develop a national social media policy"
"Broaden the sport’s understanding of child abuse and neglect"
"Encourage and promote athlete empowerment and participation"
"Provide a formal acknowledgement and apology to all members of the gymnastics community in Australia who have experienced any form of abuse in the sport"
"Develop a skills-based training and support program for all athletes to prevent and address eating disorders and disordered eating"
"Develop and refine resources relating to body image, weight management practices and eating disorders, to improve consistency and support effective implementation"
"All matters regarding child abuse and neglect, misconduct, bullying, sexual harassment, and assault be investigated externally of the sport"
"Establish interim and ongoing oversight over relevant complaints at all levels of the sport"
"Establish a toll-free triage, referral and reporting telephone service operated by SIA"
"Align current governance with Sport Australia’s Sport Governance Principles more consistently and effectively"
During this review, Sport Integrity Australia (SIA) was recommended by AHRC as the appropriate independent body to which abuse allegations in sport should be made, with SIA receiving 35 abuse allegations resulting in seven investigations which remained ongoing after the report's release. In response to the investigation, SIA introduced their National Integrity Framework for all sports in Australia in March 2021, including an independent complaints handling model for all sports which they encouraged all sports to adopt to ensure the independent and transparent handling of complaints moving forward. By the end of 2022, the Framework and the policies under it had been adopted by 81 recognised National Sports Organisations (NSO) in Australia, and adoption of the Framework and its policies was a requirement by any sporting organisation applying to be an ASC/Sport Australia recognised NSO.
Nonetheless, the introduction of the National Integrity Framework as the independent body for complaints saw controversy, with concerns were raised about a conflict of interest held by the SIA NST CEO, John Boultbee. John Boultbee was the director of the AIS from 1995 to 2001, overseeing a wide range of sports under the AIS banner, leading to the potential for a conflict of interest, that John himself acknowledged, if there were any hearings held for complaints regarding his time at the AIS. However, John stated that in the event there were any matter that related to his time at the AIS, he would recuse himself from any role in the complaint. A further conflict of interest was raised in 2022, as GA CEO, Kitty Chiller, left her GA role to become deputy chief executive of the NST, however the NST confirmed that Kitty Chiller would have no involvement in any gymnastics matter that came to tribunal.
The AHRC report details that abuse was occurring within the AIS gymnastics programs as early as the 1980s, not long after the AIS was established. ASC followed recommendation 6, releasing an apology statement to AIS athletes and setting up an independent and confidential support service called "AIS Be Heard" which was available to any former AIS athletes and staff members to link with existing support services. The AIS then launched a restoration payment scheme, offering former athletes payments ranging from $5000 to a maximum of $50,000 if they suffered abuse during their time as scholarship holders between 1981 and 2013 as well counselling and support services and the opportunity to engage with senior representatives from the ASC and AIS.
Gymnastics Australia also followed this recommendation, releasing a statement stating that it "unreservedly apologises to all athletes and family members who have experienced any form of abuse participating in the sport" and announcing its intention to adopt all 12 recommendations as overseen by their newly formed integrity committee.
During the course of the investigation in late 2020, GA stated in its 2020 annual report that it had formally commenced the on-boarding process of signing up to the National Redress Scheme, a scheme designed to assist people who have experienced institutional child sexual abuse gain access to counselling, a personal response and redress payment. However, it had not yet formally joined this scheme by November 2022, with gymnasts speaking out regarding this broken promise.
In March 2022, GA CEO, Kitty Chiller, left her role at Gymnastics Australia to become deputy CEO of the National Sports Tribunal, where she would have no involvement in any gymnastics matters that came before the NST.
2021 - 2022 - Sports Integrity Australia investigations and Gymnastics Australia restorative engagement program
During the course of the Australian Human Rights Commission (AHRC) investigation, Sport Integrity Australia (SIA) was recommended as the appropriate independent body where abuse allegations within Australian sport should be reported. At the conclusion of the AHRC report, SIA had received 35 abuse allegation complaints within the four month window that had been open for this, however only seven were assessed as worthy of an investigation that was ongoing after the release of the AHRC report. Four of the complaints were then returned with a finding of "neither substantiated or unsubstantiated", with the findings letter reminding complainants to maintain confidentiality with the families stating that they felt the process had let them down with their complaints not being properly heard or judged.
Further action was then taken by Gymnastics Australia in 2022, with the launch of their Restorative Engagement Program in early 2022. This program was designed to provide a platform for individuals and groups to formally convey their personal experiences and inform prospective changes to procedures, guidelines and behaviours within Gymnastics Australia control. All athletes and their families who had made a formal complaint as part of the SCMP policy facilitated by SIA and NST in 2020 were invited to take part in this program, with participation being voluntary. This program was however condemned by the female gymnasts and their families as Gymnastics Australia asked them to sign a non-disclosure agreement (NDA) as part of their participance while GA had not yet publicly acknowledged any of the abuse complaints handled by SIA after the AHRC's report release.
2021 - 2022 - Western Australian Institute of Sport (WAIS) investigation
As part of the Australian Human Rights Commission (AHRC) review of gymnastics, a group of 20 former Western Australian Institute of Sport (WAIS) gymnasts signed a joint submission regarding the physical, emotional and psychological abuse that was part of the training culture at WAIS. These gymnasts then participated in an ABC investigation regarding this abuse, which led to WAIS to self-refer these allegations for investigation to Sport Integrity Australia (SIA) in April 2021.
In early May 2021, in response to the release of the AHRC gymnastics report, WAIS board chair, Neil McLean released an apology statement, with former WAIS gymnasts criticising this the apology as weak, tokenistic, disingenuous and downplaying their abusive experiences:
In June 2021, SIA confirmed that they would independently investigate the abuse allegations from WAIS gymnasts, seeking to understand the culture of the WAIS program from its period of operation from 1987 to 2016 and examine the athletes' experience of abuse and harm along with the institute's current child safe policies and procedures and their effectiveness. All athletes, families, staff, coaches and personnel who participated in the WAIS WAG program were invited to make submissions, with WAIS chief executive, Steve Lawrence, removing himself from any involvement in the review to avoid a conflict of interest.
The investigation included interviews and written submissions from 92 participants and the examination of over 15,000 pages of documentation, with the final report being handed down in April 2022. This report found that "it was reasonably likely that some gymnasts suffered abuse and/or harm while participating in the Program at WAIS. This includes things such as verbal and physical abuse, unnecessary skinfold testing, weight-shaming, the expectation to train and compete with injuries, and extreme training loads. The Review also found that the policies and procedures that governed the Program did not adequately protect some of the gymnasts."
Four recommendations were handed down as part of this report, which included:
"On the grounds that there was no effective complaint process for gymnasts to raise concerns, Sport Integrity Australia recommended that WAIS adopt the National Integrity Framework and the associated independent complaint handling process.
On the basis that some of the practices were inappropriate for children, Sport Integrity Australia recommended that WAIS ensure that all sports programs involving children are child-focused and age appropriate.
In recognition of the importance of athlete welfare and the risk of potential long-term harm to athletes, Sport Integrity Australia recommended that WAIS continue to embed athlete wellbeing into policies, procedures and practices in all sport programs.
In recognition of the harm and/or abuse reasonably likely to have been suffered by some gymnasts, Sport Integrity Australia recommended that WAIS, in collaboration with the impacted gymnasts, engage in a restorative and reconciliatory process."
Former WAIS gymnasts responded to the report stating that the recommendation that they received an apology for the abuse did not go far enough, with calls for the state government and national sporting peak body to hold those who were responsible accountable with further consequences. The Gymnast Alliance Australia (GAA) also released a statement responding to the report, criticising WAIS downplaying the allegations as being historical, with abuse occurring as recently as six years prior to the report's release and also calling for the Western Australian Government and Gymnastics Australia to hold those responsible accountable with independent investigations.
WAIS responded to the report with another public apology, stating "We are sorry that your experiences were painful rather than enjoyable and we apologise that elements of the WAIS program failed you. To those who experienced abuse and harm we apologise. Sport, elite sport included, is meant to be a healthy and enjoyable experience. We are sorry that this was not your experience." This apology was critiqued upon its release for also included the statement "Can we also note that SIA referred a number of allegations of sexual abuse and/or physical abuse to the relevant authorities who had the jurisdiction to investigate these allegation but none of these allegations progressed to investigation or charges and all have been closed".
In June 2022, the Western Australian government issued a formal apology to WAIS gymnasts who had suffered abuse and mistreatment, with Sport and Recreation Minister David Templeman directing the department to undertake a comprehensive governance and culture review of WAIS and the formation of a Specialist Child Safeguarding Unit for sport. It was also announced that the WA Government Department of Sport and Recreation would also oversee and audit WAIS's compliance and implementation of the recommendations in the SIA report.
In May 2023, WAIS released a second apology, acknowledging that their April 2022 apology fell short as they prepared to participate in the recommended Reconciliatory and Restorative Process. The WAIS board also released a public commitment on the same day that included the updated apology and details on how WAIS was committing to acting in the best interests of athlete health, wellbeing and safety.
2021 - 2022 - Northern Districts Gymnastics Club controversy
In 2021, Sports Integrity Australia (SIA) referred an investigation that was conducted as part of the SCMP policy investigations to the Western Australian policy, resulting in detectives laying charges in March 2021 regarding incidents involving a former gymnastics coach between February 2019 and December 2020 while he was coaching at the Northern Districts Gymnastics Club.
While these charges were discontinued in June 2022 by the Office of the Director of Public Prosecutions, the Northern Districts Gymnastics Club came under fire during the course of the case for not informing parents of the allegations or case, a decision the club defended despite a parent removing their child and speaking out to the media.
The Northern Districts Gymnastics Club stated that once they became aware of the allegations, they sought immediate advice from authorities and stood the coach down with full pay, later terminating the coach's employment. The parent stated that they felt the club should have stated that allegations and charges had been made, the club was working with police, and given information about how to broach the subject with their children to ensure nothing had happened to their child.
2022 - Peggy Liddick sanctions
In early 2022, the National Sport Tribunal (NST) found Peggy Liddick, who had acted as the Australian women's artistic gymnastics team coach and boss from 1997 to 2016, guilty of harassing gymnast Georgia Bonora.
While Peggy Liddick had denied the allegations of bullying and emotional abuse, Georgia Bonora's complaint had been supported by her former Australian teammates, Shona Morgan, Olivia Vivian, Chloe Gilliland and Ashleigh Brennan.
The complaint was initially lodged with Gymnastics Australia (GA), before being referred to Sports Integrity Australia (SIA) in September 2020, containing allgations of misconduct, bullying and abuse between 2006 and 2012. Upon review, SIA upheld five allegations against Peggy Liddick, with an appeal application to have the matter heard by the NST seeing a further three allegations dismissed with two allegations being upheld.
As a result of the NST hearing, Peggy Liddick was suspended for four months and ordered to write an apology to Georgia Bonora:
Brazil
In 2016, gymnastics coach Fernando de Carvalho Lope was removed as national coach a month before Brazil hosted the 2016 Olympics after being accused of abusing two male athletes, aged 12 and 13 years old. He was also removed from his role as coach for the Clube MESC community center team at the time of these allegations and shifted to an administrative role, removing all contact with athletes.
In 2018, Globo TV broke the news story that alleged that Lopes had abused 40 minor gymnasts, leading to a police investigation and formal charges being laid regarding four of these victims. However, the other athletes who made allegations participated in the police investigation as witnesses.
In 2019, Lopes was banned from coaching gymnastics within Brazil. However Lopes appealed this ban, obtaining an injunction in June 2020 to continue coaching. This injunction was overruled as unfounded in 2022, banning Lopes from the sport for life with no further appeal routes available to him.
Lopes was found guilty for the crime of rape of the vulnerable on four charges and sentenced to 109 years and 8 months in prison in 2022.
Canada
Over many years, many different serious allegations of abuse and misconduct have been raised with Canadian gymnastics.
Jamie Atkin
In 2017, two coaches made formal complaints to the Alberta Gymnastics Federation (AGF) alleging that coach Jamie Atkin had an inappropriate relationship with a gymnast he coached at Airdrie Edge Gymnastics, violating the code of conduct. This resulted in a suspension from AGF.
Atkin avoided a formal hearing, instead agreeing to a series of terms and conditions which included ceasing all unnecessary physical conduct with the athlete, not to spend any time with the gymnast at any gym without another person present until the end of June 2018 and then to maintain a professional coach-athlete relationship, completion of business management, ethics and healthy relationships courses, and an extension of his AGF suspension until July 15, 2018.
In March 2018, a parent made a complaint to AGF board chair Katie Biberdorf, and federation investigation lawyer, James Smelie, asking how the federation was ensuring these terms and conditions were being followed as there was no regulation regarding this. Biberdorf initially responded that it would be addressed with the highest priority with a report back as soon as possible, however the parent never heard back from Biberdorf again.
The former president of Aidrie Edge Gymnastics Club, Brady Dalcin, then filed a formal complaint against AGF in November 2022 over its decision to keep the sanctions that had been levied in 2018 secret, stating that all coach discipline information should be made public for athlete protection. Dalcin had been a board member of the club from September 2018 to September 2020 before being the gym's president from September 2020 to June 2021, with the sanctions happening eight months before Dalcin became a board member. Due to the secrecy of these sanctions, information regarding them had never been provided to incoming officials within the gym, and upon discovery of the complaint and information, none of the Airdrie board members could answer Dalcin whether Atkin had completed the courses he agreed to within the sanctions.
Jamie Atkin continues to coach at Airdrie Edge Gymnastics Club in 2022.
Scott McFarlane and subsequent investigation
In October 2017, Gymnastics Ontario suspended coach Scott McFarlane due to internal complaints, announcing this publicly on January 26, 2018, after McFarlane was charged with sexual offences against a 15 year old athlete he had been coaching. Following his arrest, it came to light that five years earlier in April 2013, parents of a 12 year old gymnast from Tumblers Gymnastics Centre had gone to Ottawa police with complaints of an inappropriate relationship, however no charges were laid due to the alleged victims refusing to cooperate with authorities.
While McFarlane was formally acquitted on the charges in November, 2022, Gymnastics Canada extended their suspension pending an internal review of the allegations.
The McFarlane case sparked an internal investigation in Canadian gymnastics in 2018 by Shearer Parnega, a Toronto law firm, which revealed a systematic pattern of GymCan failing to act on misconduct complaints back to 2012. The outcome report was deemed so confidential that sources who participated in the investigation had never seen a copy. GymCan was criticised for keeping this report secret in 2022, with critics stating that they were being complicit in the abuse by doing so.
Dave and Elizabeth Brubaker
In December 2017, Gymnastics Canada Team Canada Head Coach, Dave Brubaker, was charged with 10 offences regarding sexual abuse of athletes under his coach. As a result, he was placed on administrative leave by Gymnastics Canada before being suspended from the organisation entirely. When the trial started in October 2018, the charges had been reduced to one count of sexual assault and one count of sexual exploitation, which Brubaker plead not guilty to. In February 2019, Brubaker was acquitted of these charges, with the judge citing that the investigating police officer was too close to the complainant to conduct an unbiased investigation, with the lack of impartiality having a tangible impact on the Crown's case.
In January 2019, a Gymnastics Canada investigation began into Dave Brubaker's wife, Elizabeth, who was provisionally suspended from coaching after written complaints regarding the time in which she was an elite coach at Bluewater Gymnastics Club. GymCan CEO Ian Moss noted that some of these allegations were related to those against her husband. GymCan also began an internal investigation into the sexual abuse allegations against Dave Brubaker after his criminal proceedings case had concluded.
In 2019, a group of 11 gymnasts filed a complaint with Gymnastics Canada (GymCan) against Dave Brubaker. This became part of the ongoing investigations following his legal case, which stretched across three years in total. The disciplinary committee concluded that 54 of the allegations were credible, with Dave Brubaker being banned for life from coaching gymnastics in Canada. The investigations regarding Elizabeth Brubaker concluded with her suspension being extended until January 18, 2024, pending the completion of reinstatement conditions.
Michel Arsenault
Former gymnastics coach and founder of Champions Gymnastics gym, Michel Arsenault, was arrested in 2018 charged with two counts of sexual assault and three counts of assault relating to gymnasts he coached between 1983 and 1993, with two being minors at the time of the alleged sexual assaults. At the time of his arrest, he was forbidden from being in contact with plaintiffs and witnesses, and forbidden from taking either paid or volunteer employment if it involved having authority over a minor.
A stay of proceedings was granted in February 2021 ahead of the scheduled March 2021 trial, due to major issues with the notes of a police investigator regarding interviews and statements by complainants and witnesses, meaning a trial could not continue without greatly affecting the right of the accused to a fair and equitable trial.
The Quebec provincial police subsequently launched an administrative probe into the investigation, investigating all of the procedures surrounding the conduct of the investigation due to great concern of how it went wrong.
Alex Bard
In 2019, Gymnastics Canada released a statement stating that national WAG team coach, Alex Bard, had resigned from his position for personal reasons. However media reports soon claimed that Bard was pushed out, which was confirmed by other GymCan staff members including GymCan CEO, Ian Moss, who stated that Bard had failed to improve on repeated incidents of inappropriate behaviour.
However, in the aftermath, details were revealed that Bard had been known to kiss young gymnasts on the lips, including on televised sporting events, harassing female coaches and touching female gymnasts inappropriately such as on the buttocks, with a complaint being taken directly to Moss in 2017 before Bard was promoted from GymCan's high performance director to GymCan WAG head coach.
Bard admitted that Moss gave Bard a choice in May 2019 to either resign or face a formal investigation into the misconduct allegations, which has since been criticised as giving him the "easy way out".
Ian Moss defended his handling of the matter as GymCan CEO in 2023, stating that "allegations are not facts", stating that only one formal complaint was filed in regards to a contractual matter that did not need an investigation due to its nature.
Despite this, Bard continued to coach in various gyms in Canada as recently as Summer 2022 due to the lack of oversight and accountability by GymCan.
Rima Nikishin
In June 2019, Coach Rima Nikishin was placed on an indefinite lifetime suspension by the Alberta Gymnastics Federation after a Code of Conduct investigation, with the reciprocity agreement meaning that no provincial and territorial GymCan organisation allowing Nikishin membership until further notice. A reason for this suspension has never been provided by Alberta Gymnastics Federation, and it is in place to this day.
Lorie Henderson
In 2021, Gymnastics Canada faced criticism for sending coach Lorie Henderson to the Tokyo Olympic Games with the gymnastics team, despite multiple abuse complaints against her remaining unresolved.
These included two 2019 complaint regarding bullying behaviour and threatening language, with one including pressure to return to training prematurely after injury, as well as a 2020 complaint alleging refusal to allow a physiotherapist access to the training facility to help build a training plan for an injured athlete as well as emotional abuse of an athlete following a bad competition. Another parent also confirmed an unresolved complaint to Canadian media outlet TSN, but feared speaking publicly due to repercussions for her daughter who remained actively involved in the sport.
Elvira Saadi
In late 2020, Gymnastics Canada suspended well-known gymnastics coach Elvira Saadi pending an investigation into abuse claims. These complaints included emotional and psychological abuse including weight-based humiliation and encouragement of eating disorders.
Marcel Rene
On November 1, 2021, provincial organisation Gymnastics Ontario handed a lifetime suspension to gymnastics coach and gym owner, Marcel Rene, effective as of January 1, 2022. This suspension included all coaching and field of play activities, as well as operation of his gymnastics club, Champion Gymnastics, other than through his son, with Gymnastics Ontario stating that they had not been appraised of information suggesting there is any risk of harm in permitting Rene the brief period of time to remove himself from the operations of Champion Gymnastics.
At the time of his suspension, Rene gave media interviews stating that there was nothing nefarious about his suspension, that it did not regard Champion Gymnastics, and that Gymnastics Ontario and Rene had an agreement rider stating he could re-apply for membership with Gymnastics Ontario in three years time.
However, by November 4, 2021, Gymnastics Ontario handed down an effective immediately interim suspension in which Rene was no longer allowed to coach and train athletes, attend any competitive events or camps, communicate with or contact anyone linked to Champions Gymnastics in regard to any "Field of Play" or operational issues, or to be onsite at Champion Gymnastics when there were also staff onsite.
This also coincided with lawyer Jason Ward contacting the Peterborough Examiner at request of his clients, Kaylie Hengg and Tonya Kirkwood, in order to provide statements of civil claims regarding sexual harassment in the workplace at Champion Gymnastics and the results of the code of conduct and ethics investigation conducted by an independent third party on behalf of Gymnastics Ontario - the investigation that had resulted in the initial November 1 ban of Rene.
Wider Gymnastics Abusive Culture Investigation
In March 2022, an open letter that amassed over 400 signatures was sent to Sport Canada demanding a third party investigation into abuse allegations within gymnastics in Canada, with the Sports Minister vowing to conduct an independent investigation by late Spring. However, by May 2022, no action had been taken in this regard. At the time of this letter, a former member of GymCan's board of directors, Kim Shore, disclosed that she had received over 100 complaints from parents over the previous five years and described a coach who had physically and emotionally abused their athletes who was still working in Canada. This letter also earned the support of U.S. Judge, Rosemarie Aquilina, who presided over the Larry Nassar sexual abuse case, with Judge Aquilina sending the gymasts a three-minute video stating that she stood with the athletes and urging Sport Canada and the Sports Minister to instigate a third party investigation where athletes had a say and were involved in the process.
In May 2022, a class action lawsuit was launched against Gymnastics Canada and the provincial gymnastics bodies across Canada in B.C., Alberta, Saskatchewan, Manitoba, Ontario and Quebec, alleging negligence. in preventing and taking action on physical and sexual abuse within their programs.
In July 2022, an open letter was launched by Gymnasts for Change, an independent group representing more than 500 gymnasts, alleging that Gymnastics Canada failed to protect gymnasts from abuse and urging the Minister of Sport, Pascale St-Onge, to suspend funding and hold a third-party investigation, as this request had been ignored for months by GymCan, Sport Canada and the Government. In response to this letter, the Minister publicly stated that funding would be frozen pending GymCan's participation with the new Office of Sports Integrity Commissioner (OSIC), which was founded in June 2022 to address reports of abuse in sports.
GymCan announced that it had signed an agreement on October 21, 2022, to join the Canadian Federal program "Abuse-Free Sport", designed to prevent and address maltreatment in sport, with complaints then going through the new Office of the Sport Integrity Commissioner (OSIC) as an independent complaint investigator.
In June 2022, GymCan hired McLaren Global Sport Solutions to design a culture review for GymCan and analyse their safe sport policies and procedures.
This report was made public in January 2023, with more than 1000 voices in the Canadian gymnastics community providing feedback, with a total of 58 personal interviews being conducted with a total of 974 individuals responding across two surveys. This report found that abuse and maltreatment of gymnasts was most pronounced in women's artistic gymnastics and women's rhythmic gymnastics, with a total of 46 recommendations being made for the final culture review.
France
In January 2023, the French Gymnastics Federation (FFG) suspended its national men's gymnastics team coach, Vitaly Marinitch, applying to the state as the formal employer for a termination of his employment citing "alcohol problems" and "inappropriate words", as well as fights regarding "ethical issues" and "all types of violence". Previously, Marinitch had been forced to resign in 2016 from USA Gymnastics for groping the wife of team member Steven Legendre on more than one occasion in 2014.
On May 4, 2023, the technical director of the Marseille-based French gymnastics center, Vincent Pateau, faced court charged with aggravated moral harassment between 2015 and 2021 against five underage athletes. While he was acquitted of two of the charges, he was convicted on three, leading to a six-month suspended prison sentence and a €10,000 fine. While the prosecution had requested fifteen months in prison suspended and a ban on coaching, no such ban was imposed at the time of sentencing. The court did not impose any ban on coaching, with the Ministry of Sports not imposing any such ban until mid-May
In mid-May 2023, Stade 2 broadcast former French gymnasts speaking out about harassment and violence within French gymnastics, as well as the results of a survey that they held which highlighted these on a wider scale.
In this program, six former athletes disclosed experiences of abuse, violence and harassment in their time in the French team, as well as a systemic disregard for the health and wellbeing of gymnasts as humans, treating them only as performance objects. Allegations included forced participation in training and demonstrations despite injuries, body shaming, pressure to lose weight through extreme diets leading to eating disorders and psychological violence, towards gymnasts who were minors at the time of the abuse.
One of the coaches mentioned in the testimonies had been previously denounced for abusive methods in Switzerland in 2007 before working with the French team, going on to be implicated by a Mexican gymnast in 2019 for similar allegations. He had not been under contract with the French Gymnastics Federation (FFG) since 2013 due to his results and behaviour being "not satisfactory".
In response to the allegations, French Sports Minister Amélie Oudéa-Castéra announced the opening of an investigation into these allegations, banning the technical director of the national gymnastics centre from practicing.
The FFG president, James Blateau, released a statement stating he was providing his "full support to the victims", and that an exceptional meeting of the federation's executive board had been called to discuss the measures to be taken.
A week after this broadcast, the Bouches-du-Rhône national gymnastics centre based in Marseille released a press statement announcing the closure of the centre on June 30, 2023, under the order of the FFG. This press release cited the trial of their technical director Vincent Plateau, the report from stage 2 and a particularly unstable financial situation as the reasons for their closure.
Another former coach of the Marseille centre, Pierre Ettel, is awaiting trial for moral harassment charges on November 7, 2023.
Italy
In early November 2022, allegations of emotional abuse within Italian rhythmic gymnastics, due to a complaint being filed in Brescia with a prosecutor relating to the abuse of two young rhythmic gymnasts regarding their requirement to maintain a specific weight. This followed former national team members, Nina Corradini and Anna Basta, speaking out about their experiences of humiliation and extreme pressure regarding their weight while spending time at a rhythmic gymnastics academy.
Due to these allegations, Italy's sports authorities began an investigation, with Sports Minister Andrea Abodi stating that medals cannot justify inappropriate behaviour and expressing her concern regarding the treatment of young athletes by coaches. A meeting was held between Abodi and the president of Italy's Olympic Committee, Giovanni Malago, and the head of the Italian Gymnastic Federation, Gherado Tecchi. Tecchi emphasised the need to care for and protect young athletes in the sport, placing their wellbeing at the utmost importance.
Italian gymnasts attended the gymnastics federation meeting, demanding a "cultural revolution" in response to the revelations of psychological abuse, with another international gymnast speaking out against the violence and emotional abuse within the sport regarding eating and weight management. Tecchi announced an investigation into the claims would be conducted, urging coaches and athletes to provide testimony in the investigation.
On November 8, 2022, the head of the Italian Olympic Committee, Giovanni Malago, issued a public apology to the group of former gymnasts, stating anyone who made mistakes would face consequences. The Italian Gymnastics Federation (FGI) also issued an apology, stating it does not tolerate any form of abuse, was committed to the wellbeing of its members, and would be taking immediate action working with the Federal Prosecutor and Safeguarding Officer to conduct investigations.
In mid-January 2023, the Federation Internationale de Gymnastique (FIG) convened an emergency council to discuss the future of Emmanuela Maccarani, the technical director of Italy's national rhythmic gymnastics training centre, and her assistant, Olga Tishina, following allegations of abuse. Maccarani denied all allegations of abuse, stating the accusers were gymnasts who did not make it to the Olympics and that envy from other coaches may be behind the case, as the Monza prosecutor's office investigated Maccarani and Tishina for alleged mistreatment of gymnasts.
This meeting resulted in Maccarani being relieved of her role as the national rhythmic gymnastics technical director, being temporarily replaced by Gherado Tecchi, the president of the Italian Gymnastics Federation (FGI). However, the Tecchi confirmed that Maccarani would continue to serve as the Italian national team's head coach until a decision was made regarding the allegations of mistreatment under investigation by both sports and criminal authorities.
In late January 2023, Stefania Fogliata, a rhythmic gymnastics coach, was suspended from coaching due to allegations of abuse of eight athletes between the ages of 10 and 14 since 2017. Preliminary investigations found that the athletes were subjected to daily insults, humiliation and physical violence from Fogliata. Testimonies were gathered from 25 different individuals alleging abuse, including victims, colleagues, parents and witnesses. The investigation concluded in March 2023, with Fogliata being disqualified from coaching for a year, and the Nemesi Academy of Calcinato, which Fogliata founded and directs, being banned for eight months.
In March 2023, artistic gymnastics coach Eleonora Gatti faced precautionary suspension by the Federal Court while awaiting trial for criminal charges relating to allegations of inappropriate behaviour towards underage athletes, both verbal and physical, and stalking. However this ban was removed in June after the testimony of four of Gatti's current athlete students who denied being ever subjected to harassment or ill-treatment. All allegations were denied by Gatti, with Gatti's criminal trial scheduled to take place in October 2023.
New Zealand
In late July 2020, Gymnastics New Zealand (GNZ) responding to the growing global focus on the mistreatment of gymnastics and allegations of abuse from Australian gymnasts by taking steps to address the issue within New Zealand. GNZ CEO Tony Compier announced the establishment of a Safe Sport email function to report abuse directly to GNZ and the formation of an athlete-based advisory group to inform GNZ's work on athlete safety and wellbeing.
Shortly after these measures were put in place, Stuff.co.nz released an investigative journalism piece on August 1, 2020, detailing serious allegations of psychological and physical abuse from former elite New Zealand gymnasts. These allegations spanned across both club and international levels, describing issues such as lifelong injuries, reliance on painkillers, anxiety and ongoing management of eating disorders. This report exposed a culture associated with weight, serious injuries, overtraining, emotional abuse from coaches and sexual inappropriateness from male judges. GNZ acknowledge the need for improvements, launching urgent investigations in response to the allegations, as concerns began to be expressed by the New Zealand Olympic Committee and Sport New Zealand.
Around the same time, parents of young gymnasts at the North Harbour Gymnastics Club came forward publicly with allegations of abuse, overtraining and fat-shaming within the program. These claims included incidents of self-harm, injured athletes being forced to train, verbal abuse, and attempts to cover up abusive behaviour. The parents started that normalisation of low-level abuse within competitive gymnastics culture had led to a fear of speaking out publicly before this point. An investigation was initiated on August 3, 2020, with the CEO of North Harbour Gymnastics expressing shock over the allegations.
Following these initial allegations, more parents and coaches came forward to express their concerns about the abusive culture with gymnastics in New Zealand. They claimed that previously, their concerns had not been taken seriously by either clubs or GNZ, leading to a lack of trust in GNZ's ability to conduct a thorough investigation. As a result, there was a demand for an independent review of the culture within gymnastics.
Additional allegations emerged, revealing discrimination against athletes who had reported concerns about abusive coaching behaviours regarding a coach who had attended a 2018 training camp. GNZ was accused of preventing Olympic hopeful athletes from competing for months after they had reported their concerns. Concerned parents had sought legal advice, with an independent party concluding that GNZ's investigation had serious procedural and substantive flaws. It was revealed that GNZ did not have an independent complaints program at the time of these reports in 2019, with High Performance Sport New Zealand stating that they held no jurisdiction over GNZ at the time.
Despite the growing number of allegations, GNZ CEO Tony Compier denied any knowledge of negative consequences for gymnasts who spoke out, defending the organisation's investigation policies and procedures. The New Zealand Sports Minister, Grant Robertson, expressed deep concern over the reports of abuse and encouraged affected athletes and parents to come forward. The Ministry of Sport NZ also implemented an anonymous complaints procedure to ensure individuals could report their experiences without fear of repercussions from GNZ.
On August 5, 2020, Gymnastics New Zealand announced the appointment of David Howman, the former head of the World Anti-Doping Agency (WADA), to conduct an independent review of the sport. This review aimed to examine all aspects of gymnastics, including policies, procedures, and remedies for both past and present complaints. The review's report was initially planned for an October 2020 release.
A week after the initial reports had been released, former New Zealand Commonwealth Games gymnast, Georgia Cervin, expressed her worry that the culture of abuse in gymnastics was so deeply ingrained in athlete, many may not even realise they had been abused, making it challenging for them to come forward and report their experiences to the review. The dismissive response from the gymnastics community, who claimed such treatment was part of the sport's toughness and challenges, further highlighted the normalisation of abuse.
Avril Enslow, the CEO of the Christchurch School of Gymnastics, also made concerning remarks in response to the allegations on public social media forums. Enslow suggested that athletes alleging an abusive culture in gymnastics were acting out of vindictiveness, making excessive allegations, which undermined the urgent need to address any problematic aspects of the sport's culture. Enslow's comments drew frustration from many, as they perpetuated and normalised the abusive culture that had been brought to light. GNZ CEO Tony Compier responded to Enslow's comments, deeming them unhelpful and emphasising the importance of encouraging individuals to come forward and share their experiences.
On August 8, 2020, Gymnastics New Zealand announced that they would step away from handling related complaints. From this point onwards, GNZ redirected any complaints made via the GNZ Safe Sport email mechanism to the Sport New Zealand Independent Complaints Mechanism (ICM). It was emphasised that the ICM operated independently, and the management of complaints would be handled by Dyhrberg Drayton Employment Law. However, it was revealed that GNZ CEO Tony Compier and another senior GNZ employee would still have access to the complaints sent via email. The Sport New Zealand ICM would assess and respond to each specific complaint, tailoring their response to the circumstances of each case. David Howman, who was leading the independent review of gymnastics in New Zealand, would also have access to information from the ICM with the consent of the complainants to address the emerging trends and themes in the review.
In late August 2020, the International Socio-Cultural research group of Women's Artistic Gymnastics (ISCWAG) published an open manifesto, which outlined eight actions the group believed should be taken to protect gymnasts from abuse. Dr. Roslyn Kerr, a participating New Zealand academic, expressed surprise that the widespread culture of abuse in gymnastics had not been exposed earlier, given the history of research and publications on the topic. Former New Zealand Commonwealth Games gymnast Georgia Cervin also participated in and signed the manifesto. GNZ stated that the recommendations from ISCWAG would likely be considered alongside the outcomes of the ongoing independent review for future practices.
By the end of August 2020, the independent review that was underway had already shed light on a number of key themes. One significant issue was the dress code surrounding leotards in gymnastics. Gymnasts had raised concerns that the current dress code served as a tool for control, intimidation, violence, and period shaming. Male coaches were alleged to make inappropriate comments about athletes' bodies, engage in abusive practices such as snapping bra straps, and deny requests to wear shorts during menstruation, and it was raised that competition judges would mark down routines if underwear was visible.
Another important theme emerging from the review was the culture of fear that prevented gymnasts from coming forward with allegations of abuse. They feared repercussions such as non-selection, isolation from peers, ostracism, and unfair judgment at competitions. Parents also expressed fear in speaking up for their children due to potential negative consequences such as inadequate coaching, unfair treatment, and biased judging. This culture of silence and fear was instilled from a young age, with gymnasts being taught to listen but not speak, act quietly, docile, and compliant. Negative reactions on social media further reinforced the fear of reporting abuse.
As the year progressed, claims began to emerge that coaches themselves were also subjected to systemic abuse. Coaches alleged verbal and psychological abuse used to silence those who had witnessed mistreatment of athletes from reporting. One coach even stated that they had observed abuse in every gym they had been in, indicating the widespread nature of the problem within the sport. Allegations of poor working conditions, such as long hours without breaks and no days off, highlighted the lack of protection for contractor or volunteer coaches under employment legislation. There were also concerns about time limits for seeking action against bullying or harassment for employees who were covered under workplace legislation.
In mid-September 2020, Gymnastics New Zealand faced criticism from former gymnasts who believed that the independent panel appointed to conduct the review was ill-equipped for the task at hand. Athlete advocates called for additional input from the Human Rights Commission and international youth sports lawyers to ensure subsequent or complementary reviews with more robustness, expertise, and comprehensive terms of reference to address the wide-ranging issues of child abuse and social concerns within the sport.
Towards the end of September 2020, judges involved in gymnastics competitions also began speaking out about their experiences of mistreatment and abuse in the sport. These judges revealed allegations of bullying and intimidation by senior and head judges, who would manipulate scores to either inflate or deflate final scores for specific athletes in order to achieve desired results. Biases among judges towards athletes from the clubs they were associated with were observed, particularly in national competitions, further highlighting the problematic behaviours within the judging system.
As 2020 came to a close, athletes continued to come forward with allegations of abusive practices. These included instances of overtraining in disregard for international and government guidelines, with athletes often being pushed to train despite injuries and against doctors' recommendations. Such practices were prevalent at both the club and elite levels, impacting athletes as young as nine years old.
As a result of the ongoing allegations from parties coming forward, the original October 2020 deadline of the independent review's report was not met, with the review ongoing into 2021.
In late January 2021, Gymnastics NZ CEO Tony Compier sent an updated Safeguarding and Child Protection Policy to clubs and members, along with a memo outlining the expectation that clubs must have an up-to-date protection policy in place, with all coaches and those holding "other key club roles" undergoing a basic level of child protection training, with a 12-month period being given for clubs to meet this requirement. Clubs were also informed that they were expected to have at least one child safeguarding representative to whom concerns could be raised, with police vetting of all new and existing coaches being carried out every three years. Concerns were raised in response to this by child protection education charity, Safeguarding Children, with CEO Willow Duffy stating that the time frame was too long and did not reflect the commitment to safeguarding children.
On February 10, 2021, Gymnastics New Zealand made public the final report detailing the findings from the past year's independent review, marking a significant milestone in the ongoing efforts to address the deeply rooted issues of abuse within the sport's culture. The report detailed findings of a culture of fear, retribution and abuse permeating the Gymnastics New Zealand community.
Lead reviewer, David Howman, supported by Dr Lesley Nicol and Rachel Vickery, produced a comprehensive 60 page document that outlined the issues plaguing New Zealand gymnastics. The review received over 200 submissions, conducting more than 100 interviews with gymnasts, coaches, officials and parents, while also receiving input from international groups such as Judge Rosemarie Aquilina, the Australian Human Rights Commission, the Athletes Federation, Gymnastics Ethics Foundation, and the Children's Commissioner to prioritise child safeguarding.
Despite the large dedicated response received from the review panel, some individuals expressed dissatisfaction with the investigation, citing a lack of adequate representation for athletes' voices, the review panel received a dedicated response - it is worth noting that only 70 athletes out of 36,000 registered participants contributed to the investigation, with the majority of submissions coming from coaches, judges, and parents.
The primary aim of the report was to assist the sport in addressing past harm, initiating positive changes, and ensuring a safe and enjoyable environment for all participants. Ten main themes were identified in the review, including the negative impact on athletes' health and well-being, the lack of voice for gymnasts, fear of retribution, unrealistic expectations, power imbalances, lack of trust, and insufficient education.
The report highlighted a number of issues within Gymnastics New Zealand, including abusive coaching, body image concerns, eating disorders, limited access to medical treatment, bias in the judging process, fears of speaking up, and a loss of trust. Athletes reported being compelled to train while injured, fearing repercussions if they refused. Parents also expressed powerlessness in intervening due to concerns about retribution.
To address these issues, the review panel made a total of 50 recommendations in total. These included the formation of an athlete commission or union to provide a confidential platform for gymnasts to express their concerns, as well as the identification of coaches perpetuating abuse and the recognition of power imbalances between coaches and child gymnasts. The report also emphasised the need for addressing body image concerns, eating disorders, medical treatment accessibility, and discomfort with training and competing in leotards. Other key recommendations included the establishment of a comprehensive complaint and reporting process, the creation of a medical and health advisory panel, the availability of qualified investigators, the inclusion of parents in observing training sessions, and a review of competition and training attire. Furthermore, the report called for a restorative process for abuse survivors, an independent complaints process, transparent judges' scoring, and the creation of a national register of coaches.It was noted that financial constraints may pose challenges to implement some of the recommendations, however that other similar limitations existed in other sports as well.
An emphasis was placed on the need for a rest and the creation of unity within the gymnastics community, and that while the New Zealand cultural issues were considered less severe than some other international cases, the recommended actions aligned with global efforts to address abuse within the sport.
It was also outlined that the successful implementation of the recommendations hinged on the establishment of a respected committee that included and centred the voices of both ex-athletes and current athletes in order to drive cultural change.
Following the release of the independent review, Gymnastics New Zealand issued a formal apology to those who have experienced abuse within the gymnastics community. The organisation expressed gratitude to those who shared their stories and experiences during the review process. Furthermore, GNZ committed to implementing the recommendations from the report and announced plans to establish a seven-member steering committee, comprising survivors, athletes, human rights representatives, and members of the gymnastics community. This steering committee would oversee the implementation of the recommendations, ensuring accountability and progress.
Collaboration was also pledged by GNZ with various stakeholders including Sport New Zealand, the Athletes Federation, and the Human Rights Commission, to address and redress the harm caused. GNZ acknowledged that no one in the sport should endure any form of abuse and emphasised its commitment to creating a safe and inclusive environment for all participants.
Criticism was raised around the decision to not outline specific incidents of abuse in the sport within the report, with the panel defending its decision by stating it did not provide explicit details as its focus was on identifying overarching themes and systemic issues with GNZ to intitate a comprehensive and transformative change.
The review and GNZ's subsequent actions in the immediate release period received public support from Sport NZ CEO Raelene Castle, who applauded the bravery of survivors for coming forward. Castle believed that GNZ's implementation of the report's recommendations, along with the involvement of the steering committee, would lead to a positive cultural shift in gymnastics. Sport NZ also publicly committed to supporting GNZ during the implementation phase as a member of the steering committee.
Gymnastics New Zealand announced their intent to share the report with the global governing body, Fédération Internationale de Gymnastique (FIG), and collaborate with other gymnastics organisations worldwide who were undergoing similar reviews. GNZ stated that through actively participating in global efforts to address abuse in gymnastics, they aimed to contribute to the overall improvement of the sport's culture and safeguarding measures.
In the days afterwards, further concerns began to be raised about the financial challenges that would be faced implementing the recommendations in the report, especially within the context of the cost of the investigation. The total cost of the investigation, including the report, incurred a cost of approximately $250,000 which was funded by Sport New Zealand. While this funding covered the review itself and the establishment of Sport NZ's Independent Complaints Mechanism that was used for the gymnastics community, the cost of implementing the 50+ recommendations within the report was placed upon GNZ presenting financial hurdles moving forward. The organisation publicly acknowledge their limited financial resources, as GNZ only received annual funding of around $3 million, primarily from participation and touring fees. GNZ reassured that affiliated clubs would not be burdened with increased fees to fund the recommendations being implemented, announcing plans to seek further financial assistance from partners and sponsors.
Additionally, calls for empowering athletes and addressing the gender disparities emerged as plans for the reform process began to take way. Former New Zealand Commonwealth Games gymnast and ISCWAG member, Dr. Georgia Cervin, noted that the review report did not adequately address the gendered nature of the problems within gymnastics, with the expectations of feminity perpetuating gender discrimination in the sport and identifying that addressing these concerns was a human rights obligation for New Zealand.
The first major guideline of the establishment of the steering committee by the end of March were missed, with GNZ stating that COVID-19 alert level changes had affected progress and caused the delay. However ISCWAG academic and survivor, Dr. Georgia Cervin, who was one of several advocates part of a group of more than 100 current and former gymnasts, coaches and judges who had been reaching out to GNZ spoke out noting that there had not been any consultation with the group showing a disconnect in GNZ's statements regarding collaboration and criticising the lack of priority given to the steering committee plans by GNZ.
In the months afterwards, some coaches within the gymnastics community expressed feeling "battered and bruised", acknowledging that many gymnastics clubs were struggling without adequate support with limited resources and multiple roles being handled by staff and volunteers posing significant challenges in implemented the changes within the given timeline.
A year on from the original Stuff investigation report, on August 1, 2021, GNZ had only fulfilled one recommendation from the review - a formal apology to survivors. Former Commonwealth Games gymnasts, Oliva Jobsis and Dr. Georgia Cervin, spoke out about feeling sidelined, with progress being insufficient and GNZ and Sport NZ employing a strategy of exhaustion and victim-blaming. Both parents and independent reviewers expressed disappointment in the lack of response and change, with Safeguarding Children's CEO, Willow Duffy, expressing concern about the ongoing risk to child gymnasts.
The steering committee, originally promised to be formed by the end of March 2021, was still under formation in September 2021, with documents being released that showed that committee was not independent due to GNZ's influence on who was appointed and their ability to remove committee members without notice, and that any recommendations were not binding to be implemented. This was criticised as creating an insufficient illusion of care, that would not see real change, and highlighted how governing bodies failed to address issues and hold perpetrators accountable while refusing to address previous recommendations. Criticism also noted that GNZ investigations seemed to be focused on acknowledging fault, but refusing to take direct responsibility with concrete action to prevent harm from recurring.
In response to this criticism, the structure of the committee was changed in late October, removing the Gymnastics NZ board representation and shifting the focus to being survivor centred, with five gymnasts with lived experience of harm and a mix of experience across codes, clubs, genders and roles within the gymnastics community being included alongside human rights and child protection experts. Despite this, the group was still answerable to the GNZ board on possible changes and the proposals were not binding, with recommendations not having to be adopted by Gymnastics NZ or its board.
With the lack of progress being made by 2022 and frustration with the lack of progress and consideration for survivor voices growing, Gymnastics NZ was forced to admit in February 2022 that they had underestimated the time it would require to change culture. However, they emphasised a long-term commitment to cultural and behavioural change in the sport, committing to implementing all recommendations received by the steering committee in the coming months, with transparency around resource constraints.
In July 2022, GNZ formally approved the steering committee's work plan, titled "Shaping the Future of Gymnastics in Aotearoa", which covered four themes: Integrity, Health and Wellbeing, Environment and Culture, and People and Programs. The Integrity theme included engaging independent experts, improving the complaints process, empowering athletes, and prioritising child and youth-centred focus. The Health and Wellbeing theme had a focus on research, medical and health panels, and a long-term athlete development framework. The Environment and Culture theme aimed to define GNZ's role in leading culture and supporting best practices in clubs. Finally, the People and Programs theme involved initiatives in coach development, judging, technical committees, and education and development programs. In total, 19 actions, projects and work streams were identified to occur over three phases, with priority actions being addressed from July 2022 into mid 2023 before long-term actions requiring complex responses beginning in mid-2023 into 2024.
Two years on from the release of the independent review report, in February 2023, survivors of historic harm were still waiting resolution, despite the ongoing assurances of positive change from those in leadership positions at GNZ. To help direct change, GNZ appointed Andrea Nelson, the former head of the 2022 Cricket World Cup, as their new CEO, and confirmed the development of a progress document to align with the road map released in July 2022. However, former gymnasts expressed regret for raising concern due to the animonsity, disbelief and accusations they had faced from the gymnastics community, including leadership and appointed officials, with parents expressing frustration for being stuck in a state of limbo regarding their complaints that were being bounced between different complaint mechanisms without resolution.
Portugal
In 2014, a peer-reviewed journal article highlighted the abuse of international female artistic gymnasts from Portugal. This research highlighted the common practices of weight control, verbal and emotional abuse, training on injuries, corporal punishment, physical abuse, and a code of silence leading to a lack of parental knowledge about the abuse in training sessions.
Romania
In 1995, Adriana Giurca was found beaten to death in a locker room. Her trainer, Florin Gheorghe, was convicted on charges relating to her death, as he physically abused her in the interest of training her to perfection. The investigation revealed significant pressure on young gymnasts in Romania and the cultures surrounding their rigorous training and what it would mean to make them successful. Adriana's parents were devastated Gheorghe was never convicted on charges of murder.
United Kingdom
After the release of the Netflix documentary, Athlete A, which exposed the scale of abuse in USA Gymnastics, gymnasts in the United Kingdom were prompted to speak out about their own abusive experiences within the sport in July 2020, detailing how complaints about welfare issues were not taken seriously by their governing body.
These gymnasts, including Nicole Pavier, detailed a culture of fear and abuse being ingrained within their training, causing issues such as eating disorders from fat shaming, training on injuries, physical abuse, and denial of their phones to seek help. These accounts prompted further athletes to speak out, including British gymnasts such as Becky and Ellie Downie, with it being exposed that UK Sport knew of abuse allegations as early as 2019.
In response to the allegations, then-British Gymnastics CEO Jane Allen expressed her deep dismay and shame, which was followed by the National Society for the Prevention of Cruelty to Children (NSPCC) and the British Athletes Commission joining forces to establish a dedicated helpline to offer support to affected gymnasts.
Gymnasts continued to express further issues, with Olympian Amy Tinkler speaking out against the time taken for British Gymnastics to take proactive action on bullying and abuse complaints she had submitted in December 2019. Nile Wilson, another Olympic medalist gymnast, stated that within the British Gymnastics "culture of abuse", athletes were treated "like pieces of meat" with their complaints being dismissed in a way that promoted a culture where athletes were afraid to speak up against the physical and emotional abuse they endured.
As the magnitude of the problem became more apparent and more allegations were made, British Gymnastics acknowledged that it had fallen short in protecting its members. As a result of this, an independent review into the allegations of mistreatment began in August 2020 under the oversight of Anne Whyte QC to assess the centrality of gymnast wellbeing and welfare in British Gymnastics culture.
During the investigation period, several coaches, including Claire Barbieri, Amanda Reddin, Helen Potter and Rory Weavers faced temporary suspensions pending investigations after being named in public allegations from gymnasts.
In October 2020, as the Whyte review was underway, then British Gymnastics CEO Jane Allen announced her December 2020 retirement, acknowledging her responsibility for the organisation's past failures in protecting athletes. A new CEO would not be named until June 2021, with Sarah Powell announced as the successor to start her new role in October 2021. Powell acknowledged the scale of reform required, stating her commitment to driving change within the gymnastics community.
In February 2021, a group of 17 individuals aged between 15 and 43 years old initiated legal action against British Gymnastics, seeking accountability for the physical and psychological abuse they endured. These allegations involved inappropriate physical form, failure to address injury, inadequate supervision, abusive coaching techniques, harmful weight management practices, bullying and lasting psychological effects. They sought improved safeguarding, transparency, and a departure from winning at all costs mentality, as well as financial compensation to seek therapy and physical aid. By March 2021, an additional 20 gymnasts had joined the group claim, further emphasizing the magnitude and systemic nature of the problem.
By March 2021, the Whyte Review had received almost 400 submissions. More than 40% of the submissions described physical abuse, while 30 submissions described sexual abuse, forcing UK Sport to admit that athlete welfare was not prioritised until 2017.
In August 2021, Mike Darcey, British Gymnastics Chairman, issued a public apology to the gymnastics community, emphasising the importance of the organisation implementing changes before the Whyte Review's completion, such as expanding the safeguarding team and providing new pathways for feedback.
In June 2022, Eloise Jotischky, an ex-acrobatics gymnast, was the first to win a civil case against British Gymnastics for the abuse she had experienced, with British Gymnastics admitting full liability for the abuse endured with a financial settlement and full apology issued.
The Whyte Review was published in mid-June 2022, finding systemic physical and emotional abuse within gymnastics with over 50% of reporting alleging emotional abuse and 40% describing physically abusive behaviour. While athlete welfare group Gymnasts for Change welcomed the view, they released a statement saying that the recommendations fell far short of what was going to be needed to change the abusive culture.
October 2022 marked the announcement by British Gymnastics that they would name banned coaches in a zero tolerance to abuse strategy for the future, with former Olympians criticising the slow progress of the group as they had only banned a small percentage of coaches named in the Whyte Review. Despite this criticism, not a single coach linked to the review received a ban after this point as of March 2023.
A documentary film entitled Gymnastics: A Culture of Abuse? exploring abuse within British Gymnastics aired on ITV 1 in February 2024.
United States
In the United States, more than 368 people, primarily minors at the time of the abuse, alleged that they were sexually assaulted by gym owners, coaches and gymnastics program staff across the country across two decades starting in the 1990s. The most high-profile of these allegations involved long term USA Gymnastics (USAG) team doctor, Larry Nassar, who was named by more than 265 athletes stating he engaged in sexual abuse for at least 14 years under the pretense of providing medical treatment, resulting in what is considered the largest sexual abuse scandal in sports history.
See also
USA Gymnastics sex abuse scandal
References
Further reading
Abuse
History of gymnastics | Abuse in gymnastics | [
"Biology"
] | 15,128 | [
"Abuse",
"Behavior",
"Aggression",
"Human behavior"
] |
71,619,423 | https://en.wikipedia.org/wiki/PGC%202933 | PGC or LEDA 2933 is a faint dwarf irregular galaxy in the Sculptor Group. It can be seen in the southern constellation Phoenix. According to measurements, the galaxy is located 11.15 million light-years away.
Because it is situated in the Sculptor Group, it is one of the closest galaxies to the Milky Way. It is obscured by a few brighter stars and galaxies (the brightest of them on the right side of the photo is 1425 light-years away from the Solar System).
The galaxy has a diameter of 2,000 light years.
References
Dwarf irregular galaxies
Sculptor Group
Phoenix (constellation)
002933
540-032 | PGC 2933 | [
"Astronomy"
] | 132 | [
"Phoenix (constellation)",
"Constellations"
] |
71,621,594 | https://en.wikipedia.org/wiki/List%20of%20grid%20computing%20projects | This is a comprehensive list of Grid computing infrastructure projects.
Grid computing infrastructure projects
BREIN uses the Semantic Web and multi-agent systems to build simple and reliable grid systems for business, with a focus on engineering and logistics management.
A-Ware is developing a stable, supported, commercially exploitable, high quality technology to give easy access to grid resources.
AssessGrid addresses obstacles to wide adoption of grid technologies by bringing risk management and assessment to this field, enabling use of grid computing in business and society.
Cohesion Platform – A Java-based modular peer-to-peer multi-application desktop grid computing platform for irregularly structured problems developed at the University of Tübingen (Germany)
The European Grid Infrastructure (EGI) – A series of projects funded by the European Commission which links over 70 institutions in 27 European countries to form a multi-science computing grid infrastructure for the European Research Area, letting researchers share computer resources
GridCOMP provides an advanced component platform for an effective invisible grid.
GridECON takes a user-oriented perspective and creates solutions to grid challenges to promote widespread use of grids.
neuGRID develops a new user-friendly grid-based research e-infrastructure enabling the European neuroscience community to perform research needed for the pressing study of degenerative brain diseases, for example, Alzheimer's disease.
OurGrid aims to deliver grid technology that can be used today by current users to solve present problems. To achieve this goal, it uses a different trade-off compared to most grid projects: it forfeits supporting arbitrary applications in favor of supporting only bag-of-tasks applications.
ScottNet NCG – A distributed neural computing grid. A private commercial effort in continuous operation since 1995. This system performs a series of functions including data synchronization amongst databases, mainframe systems, and other data repositories. E-commerce transaction processing, automated research and data retrieval, content analysis, web site monitoring, scripted and dynamic user emulation, shipping and fulfillment API integration and management, RSS and NNTP monitoring and analysis, real time security enforcement, and backup/restore functions.
BEinGRID Business Experiments in Grid.
Legion – A grid computing platform developed at the University of Virginia.
Open-source grid computing infrastructure projects
These projects attempt to make large physical computation infrastructures available for researchers to use:
3G Bridge An open-source core job bridging component between different grid infrastructures.
Berkeley NOW Project.
Debian Cluster Components.
DiaGrid grid computing network centered at Purdue University.
NESSI-GRID.
OMII-Europe – An EU-funded project established to source key software components that can interoperate across several heterogeneous grid middleware platforms.
OMII-UK Provide free open source software and support to enable a sustained future for the UK e-research community.
Open Science Grid.
SARA Computing and Networking Services in Netherlands.
Storage@home Distributed storage infrastructure developed to solve the problem of backing up and sharing petabytes of scientific results using a distributed model of volunteer managed hosts. Project was discontinued in 2011.
Worldwide LHC Computing Grid.
The Extreme Science and Engineering Discovery Environment (XSEDE), formerly Teragrid.
See also
List of volunteer computing projects
List of citizen science projects
List of crowdsourcing projects
List of free and open-source Android applications
References
Grid computing
Technology
Grid computing projects | List of grid computing projects | [
"Technology"
] | 679 | [
"Computing-related lists"
] |
71,621,595 | https://en.wikipedia.org/wiki/Rhenium%28III%29%20bromide | Rhenium(III) bromide is a chemical compound with the formula Re3Br9. It is a black lustrous crystalline solid. This compound reacts with water to form rhenium(IV) oxide and is isostructural with rhenium(III) chloride.
Preparation
This compound is prepared by the reaction of rhenium metal and bromine gas at 500 °C under nitrogen:
6Re + 9Br2 → 2Re3Br9
If there is oxygen in the atmosphere, it will instead form rhenium(III) oxybromide.
However, the most common method of producing this compound is by first reacting potassium hexabromorhenate(IV) with silver nitrate, which forms silver hexabromorhenite(IV), then this compound is heated to 600 °C to form rhenium(III) bromide.
K2ReBr6 + 2AgNO3 → Ag2ReBr6 + 2KNO3
6Ag2ReBr6 → 12AgBr + 3Br2 + 2Re3Br9
An alternative method is a thermal decomposition of rhenium(V) bromide.
References
Rhenium compounds
Bromides | Rhenium(III) bromide | [
"Chemistry"
] | 246 | [
"Bromides",
"Salts"
] |
71,622,474 | https://en.wikipedia.org/wiki/Exobasidium%20parvifolii | Exobasidium parvifolii is a species of fungus.
Description
Exobasidium parvifolii is a basidiomycete fungi in order Exobasidiales. It forms a systemic, perennial polycarpic infection of at least two species of Vaccinium; V. parvifolium and V. ovalifolium. E. parvifolii stimulates hosts to from cladomania, diseased accessory shoots, annually. Firm, vegetative galls form in the stams. In spring the stams produce up to 100 cylindrical excrescences. The fleshy protrusions eventually clad themselves with a hymenium. By early summer these turn to "shoe-string galls".
Range
Exobasidium parvifolii is found on northeastern Pacific coasts from Tlingit territory towards its northern extent to Salinan territory towards its southern extent.
Habitat
Exobasidium parvifolii grows in wet, hypermaritime forested ecosystems where their Vaccinium hosts flourish.
Ecology
Etymology
Exobasidium parvifolii translates to "exorbitant inflection" in Latin.
Taxonomy
References
Ustilaginomycotina
Fungus species | Exobasidium parvifolii | [
"Biology"
] | 256 | [
"Fungus stubs",
"Fungi",
"Fungus species"
] |
44,391,058 | https://en.wikipedia.org/wiki/Winograd%20schema%20challenge | The Winograd schema challenge (WSC) is a test of machine intelligence proposed in 2012 by Hector Levesque, a computer scientist at the University of Toronto. Designed to be an improvement on the Turing test, it is a multiple-choice test that employs questions of a very specific structure: they are instances of what are called Winograd schemas, named after Terry Winograd, professor of computer science at Stanford University.
On the surface, Winograd schema questions simply require the resolution of anaphora: the machine must identify the antecedent of an ambiguous pronoun in a statement. This makes it a task of natural language processing, but Levesque argues that for Winograd schemas, the task requires the use of knowledge and commonsense reasoning.
The challenge is considered defeated in 2019 since a number of transformer-based language models achieved accuracies of over 90%.
History
The Winograd Schema Challenge was proposed in the spirit of the Turing test. Proposed by Alan Turing in 1950, the Turing test plays a central role in the philosophy of artificial intelligence. Turing proposed that, instead of debating whether a machine can think, the science of AI should be concerned with demonstrating intelligent behavior, which can be tested. But the exact nature of the test Turing proposed has come under scrutiny, especially since an AI chatbot named Eugene Goostman claimed to pass it in 2014. One of the major concerns with the Turing test is that a machine could easily pass the test with brute force and/or trickery, rather than true intelligence.
The Winograd schema challenge was proposed in 2012 in part to ameliorate the problems that came to light with the nature of the programs that performed well on the test.
Turing's original proposal was what he called the imitation game, which involves free-flowing, unrestricted conversations in English between human judges and computer programs over a text-only channel (such as teletype). In general, the machine passes the test if interrogators are not able to tell the difference between it and a human in a five-minute conversation.
Nuance Communications announced in July 2014 that it would sponsor an annual WSC competition, with a prize of $25,000 for the best system that could match human performance. However, the prize is no longer offered.
Weaknesses of the Turing test
The performance of Eugene Goostman exhibited some of the Turing test's problems. Levesque identifies several major issues, summarized as follows:
Deception: The machine is forced to construct a false identity, which is not part of intelligence.
Conversation: A lot of interaction may qualify as "legitimate conversation"—jokes, clever asides, points of order—without requiring intelligent reasoning.
Evaluation: Humans make mistakes and judges often would disagree on the results.
Winograd schemas
The key factor in the WSC is the special format of its questions, which are derived from Winograd schemas. Questions of this form may be tailored to require knowledge and commonsense reasoning in a variety of domains. They must also be carefully written not to betray their answers by selectional restrictions or statistical information about the words in the sentence.
Origin
The first cited example of a Winograd schema (and the reason for their name) is due to Terry Winograd:
The choices of "feared" and "advocated" turn the schema into its two instances:
The schema challenge question is, "Does the pronoun 'they' refer to the city councilmen or the demonstrators?" Switching between the two instances of the schema changes the answer. The answer is immediate for a human reader, but proves difficult to emulate in machines. Levesque argues that knowledge plays a central role in these problems: the answer to this schema has to do with our understanding of the typical relationships between and behavior of councilmen and demonstrators.
Since the original proposal of the Winograd schema challenge, Ernest Davis, a professor at New York University, has compiled a list of over 140 Winograd schemas from various sources as examples of the kinds of questions that should appear on the Winograd schema challenge.
Formal description
A Winograd schema challenge question consists of three parts:
A sentence or brief discourse that contains the following:
Two noun phrases of the same semantic class (male, female, inanimate, or group of objects or people),
An ambiguous pronoun that may refer to either of the above noun phrases, and
A special word and alternate word, such that if the special word is replaced with the alternate word, the natural resolution of the pronoun changes.
A question asking the identity of the ambiguous pronoun, and
Two answer choices corresponding to the noun phrases in question.
A machine will be given the problem in a standardized form which includes the answer choices, thus making it a binary decision problem.
Advantages
The Winograd schema challenge has the following purported advantages:
Knowledge and commonsense reasoning are required to solve them.
Winograd schemas of varying difficulty may be designed, involving anything from simple cause-and-effect relationships to complex narratives of events.
They may be constructed to test reasoning ability in specific domains (e.g., social/psychological or spatial reasoning).
There is no need for human judges.
Pitfalls
One difficulty with the Winograd schema challenge is the development of the questions. They need to be carefully tailored to ensure that they require commonsense reasoning to solve. For example, Levesque gives the following example of a so-called Winograd schema that is "too easy":
The answer to this question can be determined on the basis of selectional restrictions: in any situation, pills do not get pregnant, women do; women cannot be carcinogenic, but pills can. Thus this answer could be derived without the use of reasoning, or any understanding of the sentences' meaning—all that is necessary is data on the selectional restrictions of pregnant and carcinogenic.
Activity
In 2016 and 2018, Nuance Communications sponsored a competition, offering a grand prize of $25,000 for the top scorer above 90% (for comparison, humans correctly answer to 92–96% of WSC questions). However, nobody came close to winning the prize in 2016 and the 2018 competition was cancelled for lack of prospects; the prize is no longer offered.
The Twelfth International Symposium on the Logical Formalizations of Commonsense Reasoning was held on March 23–25, 2015 at the AAAI Spring Symposium Series at Stanford University, with a special focus on the Winograd schema challenge. The organizing committee included Leora Morgenstern (Leidos), Theodore Patkos (The Foundation for Research & Technology Hellas), and Robert Sloan (University of Illinois at Chicago).
The 2016 Winograd Schema Challenge was run on July 11, 2016 at IJCAI-16. There were four contestants. The first round of the contest was to solve PDPs—pronoun disambiguation problems, adapted from literary sources, not constructed as pairs of sentences. The highest score achieved was 58% correct, by Quan Liu et al, of the University of Science and Technology, China. Hence, by the rules of that challenge, no prizes were awarded, and the challenge did not proceed to the second round. The organizing committee in 2016 was Leora Morgenstern, Ernest Davis, and Charles Ortiz.
In 2017, a neural association model designed for commonsense knowledge acquisition achieved 70% accuracy on 70 manually selected problems from the original 273 Winograd schema dataset. In June 2018, a score of 63.7% accuracy was achieved on the full dataset using an ensemble of recurrent neural network language models, marking the first use of deep neural networks that learn from independent corpora to acquire common sense knowledge. In 2019 a score of 90.1%, was achieved on the original Winograd schema dataset by fine-tuning of the BERT language model with appropriate WSC-like training data to avoid having to learn commonsense reasoning. The general language model GPT-3 achieved a score of 88.3% without specific fine-tuning in 2020.
A more challenging, adversarial "Winogrande" dataset of 44,000 problems was designed in 2019. This dataset consists of fill-in-the-blank style sentences, as opposed to the pronoun format of previous datasets.
A version of the Winograd schema challenge is one part of the GLUE (General Language Understanding Evaluation) benchmark collection of challenges in automated natural-language understanding.
References
External links
Website for the contest sponsored by Nuance Communications
https://arxiv.org/abs/2201.02387
Turing tests
Pronouns
Word-sense disambiguation | Winograd schema challenge | [
"Engineering"
] | 1,809 | [
"Artificial intelligence engineering",
"Turing tests"
] |
44,391,105 | https://en.wikipedia.org/wiki/Pisier%E2%80%93Ringrose%20inequality | In mathematics, Pisier–Ringrose inequality is an inequality in the theory of C*-algebras which was proved by Gilles Pisier in 1978 affirming a conjecture of John Ringrose. It is an extension of the Grothendieck inequality.
Statement
Theorem. If is a bounded, linear mapping of one C*-algebra into another C*-algebra , then
for each finite set of elements of .
See also
Haagerup-Pisier inequality
Christensen-Haagerup Principle
Notes
References
.
.
Inequalities
Operator algebras | Pisier–Ringrose inequality | [
"Mathematics"
] | 113 | [
"Binary relations",
"Mathematical relations",
"Inequalities (mathematics)",
"Mathematical problems",
"Mathematical theorems"
] |
44,391,262 | https://en.wikipedia.org/wiki/Evolution%20of%20biparental%20care%20in%20tropical%20frogs | The evolution of biparental care in tropical frogs is the evolution of the behaviour of a parental care system in frogs in which both the mother and father raise their offspring.
Evolution
Many tropical frogs have developed a parental care system where both the mother and father partake in raising their offspring. The evolution of biparental care, which is the joint effort of both parents, is a topic that is still under investigation. Biparentalism arose in some species of tropical frogs as a result of ecological conditions, the differences between the sexes, and their natural tendencies.
Male parental care could have served as the basis for the development of biparental care. Phylogenetic evidence shows that male parental care is the ancestral strategy in Dendrobates. Currently there are Dendrobates species, such as D. ventrimaculatus and D. fantasticus, that exhibit biparental care. The trend of using males to guard or brood eggs for biparental care or paternal care can be understood from the perspective of the female. After oviposition, or when the eggs are laid, the females need to replenish their bodies that have been dedicated to nurturing the eggs before they can mate again. Brooding by the females would delay the opportunity to mate by about two to four weeks. Since this outcome would cause many males to compete for a few females that are able to mate, the males are favored for the brooding.
Environment
The environment can have a substantial impact on the uses of parental care. Not all tropical frogs have the ability to lay their eggs plainly on land or plants. Tropical frogs can choose from a variety of water sources, such as lakes, streams, and small puddles. There is greater risk involved with reproducing in bigger bodies of water because of the higher likelihood of fish and other aquatic predators being there. Instead, frogs can choose to place eggs in phytotelmata. However, there is a trade-off that comes with electing a smaller water source. Not much sunlight reaches these locations, so algae and other food sources cannot grow to feed the inhabitants. Tropical frogs must use alternative methods of feeding their tadpole offspring. In the case of using phytotelmata, it is very difficult for one parent to guard and feed his or her offspring in possibly several different places. Roles performed by both parents provide a great advantage to the offspring. As seen in the Amazon rainforest, the different size of the bodies of water chosen for breeding correlates with the amount of biparental care in two very similar species of the genus Ranitomeya. Ranitomeya imitator favors smaller pools and uses biparental care. Conversely, Ranitomeya variabilis utilizes larger bodies of water for breeding and only males take part in parental care. The ecologic aspects of a species habitat can have significant impacts on the type of parental care exhibited.
Competition
Trophic egg feeding plays a key role in the ability of frogs to breed in smaller bodies of water that lack food sources. Many species of tropical frogs have an inherent nature of cannibalism, such as Dendrobates vanzolinii, that allow their tadpoles to utilize the eggs for nourishment. With a male guarding the eggs, an intermediate step to developing biparental care may have been using the eggs from a mating with another female to feed existing tadpoles. Males could direct where the eggs should be positioned, and then he could move them into the water that holds his tadpole offspring. This polygynous relationship puts a cost on the female because she loses eggs to benefit offspring that are not her own. It is possible that the female could counter this effect by participating in biparental care with her mate. Also, since there may be a lack of males, females could benefit from attacking other clutches that her mate might have fertilized. Eliminating competition of a female's offspring might result in higher survival of those she is trying to protect. Females have been seen eating other females' eggs in captivity by certain species, such as Dendrobates auratus. This intrasexual competition among the females might have been another important driving force for bringing about biparental care. Multiple factors contributed to the evolution of biparental care in some species of tropical frogs.
References
Frogs
Behavioral ecology
Evolutionary biology | Evolution of biparental care in tropical frogs | [
"Biology"
] | 881 | [
"Evolutionary biology",
"Behavior",
"Behavioral ecology",
"Behavioural sciences",
"Ethology"
] |
44,392,172 | https://en.wikipedia.org/wiki/Rich-club%20coefficient | The rich-club coefficient is a metric on graphs and networks, designed to measure the extent to which well-connected nodes also connect to each other. Networks which have a relatively high rich-club coefficient are said to demonstrate the rich-club effect and will have many connections between nodes of high degree. The rich-club coefficient was first introduced in 2004 in a paper studying Internet topology.
The "Rich-club" effect has been measured and noted on scientific collaboration networks and air transportation networks. It has been shown to be significantly lacking on protein interaction networks.
Definition
Non-normalized form
The rich-club coefficient was first introduced as an unscaled metric parametrized by node degree ranks. More recently, this has been updated to be parameterized in terms of node degrees k, indicating a degree cut-off. The rich-club coefficient for a given network N is then defined as:
where is the number of edges between the nodes of degree greater than or equal to k, and is the number of nodes with degree greater than or equal to k. This measures how many edges are present between nodes of degree at least k, normalized by how many edges there could be between these nodes in a complete graph. When this value is close to 1 for values of k close to , it is interpreted that high degree nodes of the network are well connected. The associated subgraph of nodes with degree at least k is also called the "Rich Club" graph.
Normalized for topology randomization
A criticism of the above metric is that it does not necessarily imply the existence of the rich-club effect, as it is monotonically increasing even for random networks. In certain degree distributions, it is not possible to avoid connecting high degree hubs. To account for this, it is necessary to compare the above metric to the same metric on a degree distribution preserving randomized version of the network. This updated metric is defined as:
where is the rich-club metric on a maximally randomized network with the same degree distribution of the network under study. This new ratio discounts unavoidable structural correlations that are a result of the degree distribution, giving a better indicator of the significance of the rich-club effect.
For this metric, if for certain values of k we have , this denotes the presence of the rich-club effect.
Generalizations
General richness properties
The natural definition of a node's "richness" is its number of neighbours. If instead we replace this with a generic richness metric on nodes r, then we can rewrite the unscaled Rich-Club coefficient as:
Where we are instead considering the sub graph on only nodes with a richness measure of at least r. For example, on scientific collaboration networks, replacing the degree richness (number of coauthors) with a strength richness (number of published papers), the topology of the rich club graph changes dramatically.
Related metrics
Assortativity
The Assortativity of a network is a measurement of how connected similar nodes are, where similarity is typically viewed in terms of node degree. Rich-club can be viewed as a more specific notation of assortativity, where we are only concerned with the connectivity of nodes beyond a certain richness metric. For example, if a network consisted of a collection of hub and spokes, where the hubs were well connected, such a network would be considered disassortative. However, due to the strong connectedness of the hubs in the network, the network would demonstrate the rich-club effect.
Applications
The rich-club coefficient of a network is useful as a heuristic measurement of the robustness of a network. A high rich-club coefficient implies that the hubs are well connected, and global connectivity is resilient to any one hub being removed. It is also useful for verifying theories that generalize to other networks. For example, the consistent observation of high rich-club coefficients for scientific collaboration networks adds evidence to the theory that within social groups, the elite tend to associate with one another.
Implementations
The rich-club coefficient has been implemented in NetworkX, a Python library for network analysis. This implementation includes both the non-normalized and normalized forms as described above.
See also
Assortativity
Preferential attachment
Structural cut-off
References
External links
NetworkX Documentation of Rich Club coefficient function
Networks
Network theory | Rich-club coefficient | [
"Mathematics"
] | 888 | [
"Network theory",
"Mathematical relations",
"Graph theory"
] |
44,393,382 | https://en.wikipedia.org/wiki/China%20Zebrafish%20Resource%20Center | The China Zebrafish Resource Center (CZRC) is a non-profit organization located in 7 Donghu South Road, Wuhan, Focusing mainly on zebrafish resources. It was established in the Institute of Hydrobiology, Chinese Academy of Sciences, in October 2012, currently headed by the board chairman Meng Anming.
Introduction
CZRC is a non-profit organization jointly supported by the Ministry of Science and Technology of China, and the Chinese Academy of Sciences. CZRC mainly focuses on collecting existing zebrafish resources and developing new lines and technologies, with the purpose of providing resources, technical and informational support for colleagues in China and overseas.
Board of directors
Honorary board chairman: Zhu Zuoyan
Board chairman: Meng Anming
Board secretary-general and director: Sun Yonghua
References
Danios
Animal models
Stem cell research
Regenerative biomedicine
Chinese Academy of Sciences
Organizations based in Wuhan | China Zebrafish Resource Center | [
"Chemistry",
"Biology"
] | 183 | [
"Stem cell research",
"Model organisms",
"Translational medicine",
"Animal models",
"Tissue engineering"
] |
44,398,234 | https://en.wikipedia.org/wiki/Link-centric%20preferential%20attachment | In mathematical modeling of social networks, link-centric preferential attachment
is a node's propensity to re-establish links to nodes it has previously been in contact with in time-varying networks. This preferential attachment model relies on nodes keeping memory of previous neighbors up to the current time.
Background
In real social networks individuals exhibit a tendency to re-connect with past contacts (ex. family, friends, co-workers, etc.) rather than strangers. In 1970, Mark Granovetter examined this behaviour in the social networks of a group of workers and identified tie strength, a characteristic of social ties describing the frequency of contact between two individuals. From this comes the idea of strong and weak ties, where an individual's strong ties are those she has come into frequent contact with. Link-centric preferential attachment aims to explain the mechanism behind strong and weak ties as a stochastic reinforcement process for old ties in agent-based modeling where nodes have long-term memory.
Examples
In a simple model for this mechanism, a node's propensity to establish a new link can be characterized solely by , the number of contacts it has had in the past. The probability for a node with n social ties to establish a new social tie could then be simply given by
where c is an offset constant. The probability for a node to re-connect with old ties is then
Figure 1. shows an example of this process: in the first step nodes A and C connect to node B, giving B a total of two social ties. With c = 1, in the next step B has a probability P(2) = 1/(2 + 1) = 1/3 to create a new tie with D, whereas the probability to reconnect with A or C is twice that at 2/3.
More complex models may take into account other variables, such as frequency of contact, contact and intercontact duration, as well as short term memory effects.
Effects on the spreading of contagions / weakness of strong ties
Understanding the evolution of a network's structure and how it can influence dynamical processes has become an important part of modeling the spreading of contagions. In models of social and biological contagion spreading on time-varying networks link-centric preferential attachment can alter the spread of the contagion to the entire population. Compared to the classic rumour spreading process where nodes are memory-less, link-centric preferential attachment can cause not only a slower spread of the contagion but also one less diffuse. In these models an infected node's chances of connecting to new contacts diminishes as their size of their social circle grows leading to a limiting effect on the growth of n. The result is strong ties with a node's early contacts and consequently the weakening of the diffusion of the contagion.
See also
BA model
Network science
Interpersonal tie
References
Network theory
Stochastic processes | Link-centric preferential attachment | [
"Mathematics"
] | 601 | [
"Network theory",
"Mathematical relations",
"Graph theory"
] |
44,398,664 | https://en.wikipedia.org/wiki/Multiconsult | Multiconsult is an engineering consultancy with 2800 employees operating in Norway, elsewhere in Europe and globally. The company is listed on the Oslo Stock Exchange.
In addition to its headquarters in Oslo, Multiconsult has local offices in several Norwegian cities. Multiconsult also operates elsewhere in Europe, Africa and Asia. In 2015, Multiconsult acquired Link Arkitektur, one of the largest architecture firms in Scandinavia.
History
Multiconsults traces its origins from the founding of Norsk Vandbygningskontor (NVK) in 1908. NVK merged with Multiconsult in 2003. The name of Multiconsult stems from 1974 when Sivilingeniørene Apeland & Mjøset AS was reorganised and Stiftelsen Multiconsult became a major shareholder.
References
External links
Construction and civil engineering companies of Norway
Companies based in Oslo
Construction and civil engineering companies established in 1973
Companies listed on the Oslo Stock Exchange
International engineering consulting firms
Geotechnical engineering companies
Norwegian companies established in 1973
Norwegian companies established in 1908
Construction and civil engineering companies established in 1908 | Multiconsult | [
"Engineering"
] | 234 | [
"Engineering consulting firms",
"International engineering consulting firms"
] |
44,398,873 | https://en.wikipedia.org/wiki/Sideromycin | Sideromycins are a group of antibiotics linked to siderophores by covalent bonds. Examples of naturally occurring sideromycins are albomycin and salmycin. Sideromycins have some unique merits as antibiotic. They can actively bypass permeability barriers (membranes) to deliver the drug inside the target bacterial cell, irrespective of the size and polarity of the antibiotic moiety contained into it. Most importantly as they are substrates of high affinity siderophore transport systems they can be effective to kill bacteria at very low concentration. Also the delivery of the antibiotic will be highly target specific, so wouldn't affect the host system. Sideromycins is being considered as a new microbe-selective antibacterial agent, which can limit the emergence of resistance.
References
Antibiotics
Siderophores | Sideromycin | [
"Biology"
] | 179 | [
"Antibiotics",
"Biocides",
"Biotechnology products"
] |
44,399,285 | https://en.wikipedia.org/wiki/Basel%20Computational%20Biology%20Conference | The Basel Computational Biology Conference (stylized as [BC]2) is a scientific meeting on the subjects of bioinformatics and computational biology. It covers a wide spectrum of disciplines, including bioinformatics, computational biology, genomics, computational structural biology, and systems biology. The conference is organized biannually by the SIB Swiss Institute of Bioinformatics in Basel, Switzerland.
The next conference
2021 [BC]2 Basel Computational Biology Conference
List of previous conferences
2019 [BC]2 Basel Computational Biology Conference "Big Data in Molecular Medicine" in association with BASEL LIFE
2017 [BC]2 Basel Computational Biology Conference
2015 [BC]2 Basel Computational Biology Conference.
2013 "Genetic Variation + Human Health"
2012 "ECCB'12, 11th European Conference on Computational Biology" in association with the 10th Basel Computational Biology conference.
2011 "Multiscale Modeling"
2010 "Regulation & Control in Biological Systems"
2009 "Molecular Evolution"
2008 "Computational Structural Biology"
2007 "From Euler to Computational Biology" in association with USGEB
2006 "Comparative Genomics"
2005 "Biological Systems In Silico"
2004 "From Information to Simulation"
2003 "Life Sciences Meet IT"
References
Computational science
Bioinformatics
Computer science conferences
Biology conferences
Science events in Switzerland | Basel Computational Biology Conference | [
"Mathematics",
"Technology",
"Engineering",
"Biology"
] | 257 | [
"Biological engineering",
"Applied mathematics",
"Computer science conferences",
"Computational science",
"Bioinformatics",
"Computer science"
] |
44,399,572 | https://en.wikipedia.org/wiki/Modern%20Meat | Modern Meat: Antibiotics, Hormones, and the Pharmaceutical Farm is a 1984 book by Orville Schell on intensive animal farming and antibiotic use in livestock.
Reviews
One reviewer said that the book is a "startling introduction to today's mass-producing factory farms" but that it had the flaw of the author's "unrestrained personal bias and overdramatization of issues".
Another reviewer said that the book was controversial and "warns of subtle—but potentially dangerous—long-range effects of 'pharmaceutical farming.'"
A reviewer summarized the book's coverage as descriptions of "the indiscriminate use of ""subtherapeutic"" antibiotics in animal feeds (probably contributing to the spread of antibiotic-resistant bacteria in both human and animal hosts); the use of diethylstilbestrol and other hormones; and (more briefly) the USDA meat-inspection programs--plus the industry's search for what could be described as nonfood feeds to simplify the stoking of four-footed machines."
The National Cattlemen's Beef Association called the book "one-sided" and "seriously flawed". Consumer advocate Ralph Nader called the book "precise and gripping".
References
External links
1984 non-fiction books
Animal welfare
Antibiotics
Books about food and drink
Intensive farming
Works about the meat industry | Modern Meat | [
"Chemistry",
"Biology"
] | 278 | [
"Biotechnology products",
"Eutrophication",
"Intensive farming",
"Antibiotics",
"Biocides"
] |
44,399,942 | https://en.wikipedia.org/wiki/Single-stranded%20binding%20protein | Single-stranded binding proteins (SSBs) are a class of proteins that have been identified in both viruses and organisms from bacteria to humans.
Viral SSB
Although the overall picture of human cytomegalovirus (HHV-5) DNA synthesis appears typical of the herpesviruses, some novel features are emerging.
Structure
In ICP8, the herpes simplex virus (HSV-1) single-strand DNA-binding protein (ssDNA-binding protein (SSB)), the head consists of the eight alpha helices. The front side of the neck region consists of a five-stranded beta-sheet and two alpha helices, whereas the back side is a three-stranded beta-sheet The shoulder part of the N-terminal domain contains an alpha-helical and beta-sheet region. The herpes simplex virus (HSV-1) SSB, ICP8, is a nuclear protein that, along other replication proteins is required for viral DNA replication during lytic infection.
Mechanism
Six herpes virus-group-common genes encode proteins that likely constitute the replication fork machinery, including a two-subunit DNA polymerase, a Helicase-primase complex and a single-stranded DNA-binding protein. The human herpesvirus 1 (HHV-1) single-strand DNA-binding protein ICP8 is a 128kDa zinc metalloprotein. Photoaffinity labeling has shown that the region encompassing amino acid residues 368-902 contains the single-strand DNA-binding site of ICP8. The HHHV-1 UL5, UL8, and UL52 genes encode an essential heterotrimeric DNA helicase-primase that is responsible for concomitant DNA unwinding and primer synthesis at the viral DNA replication fork. ICP8 may stimulate DNA unwinding and enable bypass of cisplatin damaged DNA by recruiting the helicase-primase to the DNA.
Bacterial SSB
SSB protein domains in bacteria are important maintaining DNA metabolism, more specifically DNA replication, repair and recombination. It has a structure of three beta-strands to a single six-stranded beta-sheet to form a dimer.
Eukaryotic replication protein A
Replication protein A is the functional equivalent of SSB in the nucleus of eukaryotic cells, though there is no sequence homology.
Eukaryotic mitochondrial SSB
The mitochondria of eukaryotic cells contain their own single stranded DNA binding protein. Human mitochondrial SSB (mtSSB) binds to single-stranded mitochondrial DNA as a tetramer and has sequence similarity to bacterial SSB. Human mtSSB is encoded by the SSBP1 gene. In yeast, it is encoded by the RIM1 gene.
Role in Genome Repair and Anti-aging
Recently, it has been found that it 1. Helps protect the genome, 2. Is vital for stem cells and 3. Is involved with maintaining telomere length.
See also
DNA-binding protein
Replication protein A
Comparison of nucleic acid simulation software
References
External links
SSB in PFAM
Protein families
DNA replication
Proteins
DNA-binding substances | Single-stranded binding protein | [
"Chemistry",
"Biology"
] | 656 | [
"Genetics techniques",
"Biomolecules by chemical classification",
"Protein classification",
"DNA replication",
"Molecular genetics",
"DNA-binding substances",
"Molecular biology",
"Proteins",
"Protein families"
] |
44,399,944 | https://en.wikipedia.org/wiki/Single-strand%20DNA-binding%20protein | Single-strand DNA-binding protein (SSB) is a protein found in Escherichia coli (E. coli) bacteria, that binds to single-stranded regions of deoxyribonucleic acid (DNA). Single-stranded DNA is produced during all aspects of DNA metabolism: replication, recombination, and repair. As well as stabilizing this single-stranded DNA, SSB proteins bind to and modulate the function of numerous proteins involved in all of these processes.
Active E. coli SSB is composed of four identical 19 kDa subunits. Binding of single-stranded DNA to the tetramer can occur in different "modes", with SSB occupying different numbers of DNA bases depending on a number of factors, including salt concentration. For example, the (SSB)65 binding mode, in which approximately 65 nucleotides of DNA wrap around the SSB tetramer and contact all four of its subunits, is favoured at high salt concentrations in vitro. At lower salt concentrations, the (SSB)35 binding mode, in which about 35 nucleotides bind to only two of the SSB subunits, tends to form. Further work is required to elucidate the functions of the various binding modes in vivo.
Bacterial SSB
SSB protein domains in bacteria are important in its function of maintaining DNA metabolism, more specifically DNA replication, repair, and recombination. It has a structure of three beta-strands to a single six-stranded beta-sheet to form a protein dimer.
See also
DNA-binding protein
Single-stranded binding protein
Comparison of nucleic acid simulation software
References
External links
SSB in PFAM
Protein families
DNA replication
Proteins
DNA-binding substances
DNA-binding proteins | Single-strand DNA-binding protein | [
"Chemistry",
"Biology"
] | 363 | [
"Genetics techniques",
"Biomolecules by chemical classification",
"Protein classification",
"DNA replication",
"Proteins",
"Molecular genetics",
"DNA-binding substances",
"Molecular biology",
"Protein families"
] |
44,400,621 | https://en.wikipedia.org/wiki/Shared%20snapshot%20objects | In distributed computing, a shared snapshot object is a type of data structure, which is shared between several threads or processes. For many tasks, it is important to have a data structure, that can provide a consistent view of the state of the memory. In practice, it turns out that it is not possible to get such a consistent state of the memory by just accessing one shared register after another, since the values stored in individual registers can be changed at any time during this process. To solve this problem, snapshot objects store a vector of n components and provide the following two atomic operations: update(i,v) changes the value in the ith component to v, and scan() returns the values stored in all n components.
Snapshot objects can be constructed using atomic single-writer multi-reader shared registers.
In general, one distinguishes between single-writer multi-reader (swmr) snapshot objects and multi-writer multi-reader (mwmr) snapshot objects. In a swmr snapshot object, the number of components matches the number of processes and only one process Pi is allowed to write to the memory position i and all the other processes are allowed to read the memory. In contrast, in a mwmr snapshot object all processes are allowed to write to all positions of the memory and are allowed to read the memory as well.
General
A shared memory is partitioned into multiple parts. Each of these parts holds a single data value. In the single-writer multi-reader case each process Pi has a memory position i assigned and only this process is allowed to write to the memory position. However, every process is allowed to read any position in the memory. In the multi-writer multi-reader case, the restriction changes and any process is allowed to change any position of the memory. Any process Pi {1,...,n} in an n-process system is able to perform two operations on the snapshot object: scan() and update(i,v). The scan operation has no arguments and returns a consistent view of the memory. The update(i,v) operation updates the memory at the position i with the value v.
Both types of operations are considered to occur atomically between the call by the process and the return by the memory. More generally speaking, in the data vector each entry dk corresponds to the argument of the last linearized update operation, which updates part k of the memory.
In order to get the full benefit of shared snapshot objects, in terms of simplifications for validations and constructions, there are two other restrictions added to the construction of snapshot objects. The first restriction is an architectural one, meaning that any snapshot object is constructed only with single-writer multi-reader registers as the basic element. This is possible for single-writer multi-reader snapshots. For multi-writer multi-reader snapshot objects it is possible to use multi-reader multi-writer registers, which can in turn be constructed from single-writer multi-reader registers.
In distributed computing the construction of a system is driven by the goal, that the whole system is making progress during the execution. Thus, the behaviour of a process should not bring the whole system to a halt (Lock-freedom). The stronger version of this is the property of wait-freedom, meaning that no process can prevent another process from terminating its operation. More generally, this means that every operation has to terminate after a finite number of steps regardless of the behaviour of other processes. A very basic snapshot algorithm guarantees system-wide progress, but is only lock-free. It is easy to extend this algorithm, so that it is wait-free. The algorithm by Afek et al., which is presented in the section Implementation has this property.
Implementation
Several methods exists to implement shared snapshot objects. The first presented algorithm provides a principal implementation of a snapshot objects. However, this implementation only provides the property of lock-freedom. The second presented implementation proposed by Afek et al. has a stronger property called wait-freedom. An overview of other implementations is given by Fich.
Basic swmr snapshot algorithm
The basic idea of this algorithm is that every process executing the scan() operations, reads all the memory values twice. If the algorithm reads exactly the same memory content twice, no other process changed a value in between and it can return the result. A process, which executes an update(i,v) operation, just update its value in the memory.
function scan()
while true
a[1..n] := collect;
b[1..n] := collect;
if (∀i∈{1, .., n} location i was not changed between the reads of it during the two collects)) then
return b; // double collect successful
loop
end
function update(i, v)
M[i] := v;
end
This algorithm provides a very basic implementation of snapshot objects. It guarantees that the system proceeds, while individual threads can starve due to the behaviour of individual processes. A process Pi can prevent another process Pj from terminating a scan() operation by always changing its value, in between the two memory collects. Thus, the algorithm is lock-free, but not wait-free. To hold this stronger the property, no process is allowed to starve due to the behavior of other processes. Figure 1 illustrates the problem. While P1 tries to execute the scan() operation, a second process P2 always disturbs the "double-collect". Thus, the scanning process always has to restart the operation and can never terminates and starves.
Single-Writer Multi-Reader implementation by Afek et al.
The basic idea of the swmr snapshot algorithm by Afek et al. is that a process can detect whether another process changed its memory location and that processes help each other. In order to detect if another process changed its value, a counter is attached to each register and a process increases the counter on every update. The second idea is that, every process who updates its memory position also performs a scan() operation and provides its "view of the memory" in its register to other processes. A scanning process can borrow this scan result and return it.
Based on unbounded memory
Using this idea one can construct a wait-free algorithm that uses registers of unbounded size. A process performing an update operation can help a process to complete the scan. The basic idea is that if a process sees another process updating a memory location twice, that process must have executed a complete, linearized, update operation in between. To implement this, every update operation first performs a scan of the memory and then writes the snapshot value atomically together with the new value v and a sequence number. If a process is performing a scan of the memory and detects that a process updated the memory part twice, it can "borrow" the "embedded" scan of the update to complete the scan operation.
function scan() // returns a consistent view of the memory
for j = 1 to n do moved[j] := 0 end
while true do
a[1..n] := collect; // collects (data, sequence, view) triples
b[1..n] := collect; // collects (data, sequence, view) triples
if (∀j∈{1, ..., n}) (a[j].seq = b[j].seq) then
return (b[1].data, ..., b[n].data) // no process changed memory
else for j = 1 to n do
if a[j].seq ≠ b[j].seq then // process moved
if moved[j] = 1 then // process already moved before
return b[j].view;
else moved[j] := moved[j] + 1;
end
end
end function
procedure update(i,v) // updates the registers with the data-values, updates the sequence number, embedded scan
s[1..n] := scan; // embedded scan
ri := (v, ri.seq = ri.seq + 1, s[1..n]);
end procedure
Every register consists of a field for the data-value, the sequence number and a field for the result of the last embedded scan, collected before the last update. In each scan operation the process Pi can decide whether a process changed its memory using the sequence number. If there is no change to the memory during the double collect, Pi can return the result of the second scan. Once the process observes that another process updated the memory in between, it saves this information in the moved field. If a process Pj changed its memory twice during the execution of the scan(), the scanning process Pi can return the embedded scan of the updating process, which it saved in its own register during its update operation.
These operations can be linearized by linearizing each update() operation at its write to the register. The scan operation is more complicated to linearize. If the double collect of the scan operation is successful the scan operation can be linearized at the end of the second scan. In the other case - one process updated its register two times - the operation can be linearized at the time the updating process collected its embedded scan before writing its value to the register.
Based on bounded memory
One of the limitations of the presented algorithm is that it is based on an unbounded memory since the sequence number will increase constantly. To overcome this limitation, it is necessary to introduce a different way to detect whether a process has changed its memory position twice in between. Every pair of processes communicates using two single-writer single-reader (swsr) registers, which contains two atomic bits. Before a process starts to perform a "double collect", it copies the value of its partner process to its own register. If the scanner-process Pi observes after executing the "double-collect" that the value of the partner process Pj has changed in between it indicates that the process has performed an update operation on the memory.
function scan() // returns a consistent view of the memory
for j=1 to n do moved[j] := 0 end
while true do
for j=1 to n do qi,j := rj.pj,i end
a[1..n] := collect; // collects (data, bit-vector, toggle, view) triples
b[1..n] := collect; // collects (data, bit-vector, toggle, view) triples
if (∀j∈{1, ...,n}) (a[j].pj,i = b[j].pj,i = qi,j) and a[j].toggle = b[j].toggle then
return (b[1].data, ..., b[n].data) // no process changed memory
else for j=1 to n do
if (a[j].pj,i ≠ qi,j) or (b[j].pj,i ≠ qi,j) or (a[j].toggle ≠ b[j].toggle) then // process j performed an update
if moved[j] = 2 then // process already moved before
return b[j].view;
else moved[j] := moved[j] + 1;
end
end
end function
procedure update(i,v) // updates the registers with the data-value, "write-state" of all registers, invert the toggle bit and the embedded scan
for j = 1 to n do f[j] := ¬qj,i end
s[1..n] := scan; // embedded scan
ri := (v, f[1..n], ¬ri.toggle, s[1..n]);
end procedure
The unbounded sequence number is replaced by two handshake bits for every pair of processes. These handshake bits are based on swsr registers and can be expressed by a matrix M, where process Pi is allowed to write to row i and is allowed to read the handshake bits in a column i. Before the scanning-process performs the double-collect it collects all the handshake bits from all registers, by reading its column. Afterwards, it can decide whether a process changed its value during the double value or not. Therefore, the process just has to compare the column again with the initially read handshake bits. If only one process Pj has written twice, during the collection of Pi it is possible that the handshake bits do not change during the scan. Thus, it is necessary to introduce another bit called "toggle bit", this bit is changed in every write. This makes it possible to distinguish two consecutive writes, even though no other process updated its register. This approach allows to substitute the unbounded sequence numbers with the handshake bits, without changing anything else in the scan procedure.
While the scanning process Pi uses a handshake bit to detect whether it can use its double collect or not, other processes may also perform update operations. As a first step, they read again the handshake bits provided by the other processes, and generate the complement of them. Afterwards these processes again generate the embedded scan and save the updated data-value, the collected - complemented - handshake bits, the complemented toggle bit and the embedded scan to the register.
Since the handshake bits equivalently replace the sequence numbers, the linearization is the same as in the unbounded memory case.
Multi-Writer Multi-Reader implementation by Afek et al.
The construction of multi-writer multi-reader snapshot object assumes that n processes are allowed to write to any location in the memory, which consists of m registers. So, there is no correlation, between process id and memory location anymore. Therefore, it is not possible anymore to couple the handshake bits or the embedded scan with the data fields. Hence, the handshake bits, the data memory and the embedded scan cannot be stored in the same register and the write to the memory is not an atomic operation anymore.
Therefore, the update() process has to update three different registers independently. It first has to save the handshake bits it reads, then do the embedded scan and finally saves its value to the designated memory position. Each write independently appears to be done atomically, but together they are not. The new update() procedure leads to some changes in the scan() function. It is not sufficient anymore to read the handshake bits and collect the memory content twice. In order to detect a beginning update process, a process has to collect the handshake bits a second time, after collecting the memory content.
If a double-collect fails, it is now necessary that a process sees another process moving three times before borrowing the embedded scan. Figure 3 illustrates the problem. The first double-collect fails, because an update process started before the scan operation finishes its memory-write during the first double collect. However, the embedded scan of this write is performed and saved, before P1 starts scanning the memory and therefore no valid Linearization point. The second double-collect fails, because process P2 starts a second write and updated its handshake bits. In the swmr scenario, we would now borrow the embedded scan and return it. In the mwmr scenario, this is not possible because the embedded scan from the second write is still not linearized within the scan-interval (begin and end of operation). Thus, the process has to see a third change from the other process to be entirely sure that at least one embedded scan has been linearized during the scan-interval. After the third change by one process, the scanning process can borrow the old memory value without violating the linearization criterion.
Complexity
The basic presented implementation of shared snapshot objects by Afek et al. needs memory operations. Another implementation by Anderson, which was developed independently, needs an exponential number of operations . There are also randomized implementations of snapshot objects based on swmr registers using operations. Another implementation by Israeli and Shirazi, using unbounded memory, requires operations on the memory. Israeli et al. show in a different work the lower bound of low-level operations for any update operation. The lower bound is , where w is the number of updaters and r is the number of scanners. Attiya and Rachman present a deterministic snapshot algorithm based on swmr registers, which uses operations per update and scan. Applying a general method by Israeli, Shaham, and Shirazi this can be improved to an unbounded snapshot algorithm, which only needs operations per scan and operations per update. There are further improvements introduced by Inoue et al., using only a linear number of read and write operations. In contrast to the other presented methods, this approach uses mwmr registers and not swmr registers.
Applications
There are several algorithms in distributed computing which can be simplified in design and/or verification using shared snapshot objects. Examples of this are exclusion problems, concurrent time-stamp systems, approximate agreement, randomized consensus and wait-free implementations of other data structures. With mwmr snapshot objects it is also possible to create atomic multi-writer multi-reader registers.
See also
Shared register
Shared memory (interprocess communication)
Shared memory architecture
Distributed shared memory
Linearizability
References
Distributed computing problems
Distributed computing | Shared snapshot objects | [
"Mathematics"
] | 3,654 | [
"Mathematical problems",
"Distributed computing problems",
"Computational problems"
] |
44,400,805 | https://en.wikipedia.org/wiki/Kosmos%20382 | Kosmos 382 was a Soviet Soyuz 7K-L1E modification of a Soyuz 7K-L1 "Zond" spacecraft and was successfully test launched into Low Earth Orbit on a Proton rocket designated as (Soyuz 7K-L1E No.2) on December 2, 1970.
The main purpose of the mission was to test the N1/L3 spacecraft's Block D lunar orbit insertion/descent stage by simulating the lunar orbit insertion burn, the lunar orbit circularization burn and the final lunar descent burn. Over the course of five days, the Block D stage was ignited three times to raise the initial ~190 km × ~300 km × 51.6° orbit to a final 2577 km × 5082 km × 55.87° orbit. The Block D stage was fitted with cameras in the tanks to monitor the fuel and oxidizer behaviour in weightlessness and during acceleration. Kosmos-382 also carried other experiments, including a prototype environmental control subsystem named "Rosa" for producing potable water from atmospheric condensate exhaled by cosmonauts onboard Soviet crewed spacecraft. This system was later used on the Salyut space stations in the 1970s and 1980s.
The following maneuvers were performed:
190 km x 300 km orbit to 303 km x 5038 km orbit (delta-V=982 meters/second;
318 km x 5040 km orbit to 1616 km x 5071 km orbit (deltaV= 285 m/s);
1616 km x 5071 km orbit to 2577 km x 5082 km orbit (deltaV= 1311 m/s).
See also
1970 in spaceflight
Zond program
References
External links
Kosmos 382 @ Gunther's Space Page
Zond program
Spacecraft launched in 1970
1970 in spaceflight | Kosmos 382 | [
"Astronomy"
] | 375 | [
"Outer space stubs",
"Outer space",
"Astronomy stubs"
] |
44,401,568 | https://en.wikipedia.org/wiki/Hierarchical%20editing%20language%20for%20macromolecules | The hierarchical editing language for macromolecules (HELM) is a method of describing complex biological molecules. It is a notation that is machine readable to render the composition and structure of peptides, proteins, oligonucleotides, and related small molecule linkers.
HELM was developed by a consortium of pharmaceutical companies in what is known as the Pistoia Alliance. Development began in 2008. In 2012 the notation was published openly and for free.
The HELM open source project can be found on GitHub.
Background
The need for HELM became obvious as researchers began working on modeling and computational projects involving molecules and engineered biomolecules of this type. There was not a language to describe the entities in an accurate manner which described both the composition and the complex branching and structure common in these entity types. Protein sequences can describe larger proteins and chemical language files such as mol files can describe simple peptides. But the complexity of new research biomolecules makes describing large complex molecules difficult with chemical formats, and peptide formats are not sufficiently flexible to describe non-natural amino acids and other chemistries.
Design
In HELM, molecules are represented at four levels in a hierarchy:
Complex polymer
Simple polymer
Monomer
Atom
Monomers are assigned short unique identifiers in internal HELM databases and can be represented by the identifier in strings. The approach is similar to that used in Simplified molecular-input line-entry system (SMILES). An exchangeable file format allows sharing of data between companies who have assigned different identifiers to monomers.
Examples
(For now, see the following external links: "HELM notation" on HELM wiki, and test data file.)
Adoption
In 2014 ChEMBL announced plans to adopt HELM by 2014. The informatics company BIOVIA developed a modified Molfile format called the Self-Contained Sequence Representation (SCSR) A standard which can incorporate individual attempts to solve the problem and be used universally and avoid proliferating standards is a goal of HELM.
Tools
An editor tool is needed to visualize and work with biomolecules at the correct level of detail. The editor is needed to "zoom out" to see a large molecule at the amino-acid sequence level, then "zoom in" to the atomic level at a particular site of conjugation or derivatization.
The HELM Editor and HAbE (HELM Antibody Editor) are two client tools which may in the future be released as web-based applications.
Pistoia Alliance
At a conference in Pistoia, Italy, a group of researchers from Pfizer, AstraZeneca, GlaxoSmithKline, and Novartis formed what came to be known as the Pistoia Alliance. All parties were interested in solving problems for data aggregation, data sharing and analytics for pharmaceutical research. The alliance was incorporated in 2008. The alliance is now composed of informatics experts and researchers from industry, academia and life science service organizations.
See also
Simplified molecular-input line-entry system (SMILES)
International Chemical Identifier (InChI)
Molecular Query Language
Molecule editor
Chemical table file
PLN protein line notation
Molecular graphics
FASTA
References
Chemical nomenclature
Encodings
Chemical file formats
Bioinformatics | Hierarchical editing language for macromolecules | [
"Chemistry",
"Engineering",
"Biology"
] | 655 | [
"Biological engineering",
"Chemistry software",
"Bioinformatics",
"nan",
"Chemical file formats"
] |
44,401,875 | https://en.wikipedia.org/wiki/Taxonomy%20of%20Narcissus | The taxonomy of Narcissus is complex, and still not fully resolved. Known to the ancients, the genus name appears in Graeco-Roman literature, although their interest was as much medicinal as botanical. It is unclear which species the ancients were familiar with. Although frequently mentioned in Mediaeval and Renaissance texts it was not formally described till the work of Linnaeus in 1753. By 1789 it had been grouped into a family (Narcissi) but shortly thereafter this was renamed Amaryllideae, from which comes the modern placement within Amaryllidaceae, although for a while it was considered part of Liliaceae.
Many of the species now considered to be Narcissus were in separate genera during the nineteenth century, and the situation was further confused by the inclusion of many cultivated varieties. By 1875 the current circumscription was relatively settled. By 2004 phylogenetic studies had allowed the place of Narcissus within its fairly large family to be established, nested within a series of subfamilies (Amaryllidoideae) and tribes (Narcisseae). It shares its position in the latter tribe with Sternbergia.
The infrageneric classification has been even more complex and many schemes of subgenera, sections, subsections and series have been proposed, although all had certain similarities. Most authorities now consider there to be 10 – 11 sections based on phylogenetic evidence. The problems have largely arisen from the diversity of the wild species, frequent natural hybridisation and extensive cultivation with escape and subsequent naturalisation. The number of species has varied anywhere from 16 to nearly 160, but is probably around 50 – 60.
The genus appeared some time in the Late Oligocene to Early Miocene eras, around 24 million years ago, in the Iberian Peninsula. While the exact origin of the word Narcissus is unknown it is frequently linked to its fragrance which was thought to be narcotic, and to the legend of the youth of that name who fell in love with his reflection. In the English language the common name Daffodil appears to be derived from the Asphodel with which it was commonly compared.
History
Early
Narcissus was first described by Theophrastus (, c 371 - c 287 BC) in his Historia Plantarum () as , referring to N. poeticus, but comparing it to Asphodelus (). Theophrastus' description was frequently referred to at length by later authors writing in Latin such as Pliny the Elder (Gaius Plinius Secundus, 23 AD – 79 AD) from whom came the Latin form (see also Culture). Pliny's account is from his Natural History (). Like his contemporaries, his interests were as much therapeutic as botanical. Another much-cited Greek authority was Dioscorides (, 40 AD – 90 AD) in his De Materia Medica (). Both authors were to remain influential until at least the Renaissance, given that their descriptions went beyond the merely botanical, to the therapeutic (see also Antiquity).
An early European reference is found in the work of Albert Magnus (c. 1200 – 1280), who noted in his the similarity to the leek. William Turner in his A New Herball (1551) cites all three extensively in his description of the plant and its properties. It was to remain to Linnaeus in 1753 to formally describe and name Narcissus as a genus in his Species Plantarum, at which time there were six known species (N. poeticus, N. pseudonarcissus, N. bulbocodium, N. serotinus, N. jonquilla and N. tazetta). At that time, Linnaeus loosely grouped it together with 50 other genera into his Hexandria monogynia.
Modern
It was de Jussieu in 1789 who first formally created a 'family' (Narcissi), as the seventh 'Ordo' (Order) of the third class (Stamina epigyna) of Monocots in which Narcissus and 15 other genera were placed. The use of the term Ordo at that time was closer to what we now understand as Family, rather than Order. The family has undergone much reorganisation since then, but in 1805 it was renamed after a different genus in the family, Amaryllis, as 'Amaryllideae' by Jaume St.-Hilaire and has retained that association since. Jaume St.-Hilaire divided the family into two unnamed sections and recognised five species of Narcissus, omitting N. serotinus.
De Candolle brought together Linnaeus' genera and Jussieau's families into a systematic taxonomy for the first time, but included Narcissus (together with Amaryllis) in the Liliaceae in his Flore française (1805-1815) rather than Amaryllidaceae, a family he had not yet recognised. Shortly thereafter he separated the 'Amaryllidées' from 'Liliacées' (1813), though attributing the term to Brown's 'Amaryllideae' in the latter's Prodromus (1810) rather than St.-Hilaire's 'Amaryllidées'. He also provided the text to the first four volumes of Redouté illustrations in the latter's Les liliacées between 1805 and 1808 (see illustration here of N. candidissimus).
Historically both wide and narrow interpretations of the genus have been proposed. In the nineteenth century genus splitting was common, favouring the narrow view. Haworth (1831) using a narrow view treated many species as separate genera, as did Salisbury (1866). These authors listed various species in related genera such as Queltia (hybrids), Ajax (=Pseudonarcissus) and Hermione (=Tazettae), sixteen in all in Haworth's classification. In contrast, Herbert (1837) took a very wide view reducing Harworth's sixteen genera to six. Herbert, treating the Amaryllidacea as an 'order' as was common then, considered the narcissi to be a suborder, the Narcisseae, the six genera being Corbularia, Ajax, Ganymedes, Queltia, Narcissus and Hermione and his relatively narrow circumscription of Narcissus having only three species. Later Spach (1846) took an even wider view bringing most of Harworth's genera into the genus Narcissus, but as separate subgenera. By the time that Baker (1875) wrote his monograph all of the genera with one exception were included as Narcissus. The exception was the monotypic group Tapeinanthus which various subsequent authors have chosen to either exclude (e.g. Cullen 1986) or include (e.g. Webb 1978, 1980). Today it is nearly always included.
The eventual position of Narcissus within the Amaryllidaceae family only became settled in the twenty-first century with the advent of phylogenetic analysis and the Angiosperm Phylogeny Group system. The genus Narcissus belongs to the Narcisseae tribe, one of 13 within the Amaryllidoideae subfamily of the Amaryllidaceae. It is one of two sister clades corresponding to genera in the Narcisseae, being distinguished from Sternbergia by the presence of a paraperigonium, and is monophyletic.
Subdivision
The infrageneric phylogeny of Narcissus still remains relatively unsettled. The taxonomy has proved very complex and difficult to resolve, particularly for the Pseudonarcissus group. This is due to a number of factors, including the diversity of the wild species, the ease with which natural hybridisation occurs, and extensive cultivation and breeding accompanied by escape and naturalisation.
De Candolle, in the first systematic taxonomy of Narcissus, arranged the species into named groups, and those names (Faux-Narcisse or Pseudonarcissus, Poétiques, Tazettes, Bulbocodiens, Jonquilles) have largely endured for the various subdivisions since and bear his name. The evolution of classification was confused by including many unknown or garden varieties, until Baker (1875) made the important distinction of excluding all specimens except the wild species from his system. He then grouped all of the earlier related genera as sections under one genus, Narcissus, the exception being the monotypic Tapeinanthus. Consequently, the number of accepted species has varied widely.
A common modern classification system has been that of Fernandes (1951, 1968, 1975) based on cytology, as modified by Blanchard (1990) and Mathew (2002), although in some countries such as Germany, the system of Meyer (1966) was preferred. Fernandes described two subgenera based on basal chromosome number, Hermione, n = 5 (11) and Narcissus, n = 7 (13). He further subdivided these into ten sections (Apodanthi, Aurelia, Bulbocodii, Ganymedes, Jonquillae, Narcissus, Pseudonarcissi, Serotini, Tapeinanthus, Tazettae), as did Blanchard later.
In contrast to Fernandes, Webb's treatment of the genus for the Flora Europaea (1978, 1980) prioritised morphology over genetics, and abandoned the subgenera ranks. He also restored De Candolle's original nomenclature, and made a number of changes to section Jonquilla, merging the existing subsections, reducing Apodanthi to a subsection of Jonquilla, and moving N. viridiflorus from Jonquilla to a new monotypic section of its own (Chloranthi). Finally, he divided Pseudonarcissus into two subsections. Blanchard (1990), whose Narcissus: a guide to wild daffodils has been very influential, adopted a simple approach, restoring Apodanthae, and based largely on ten sections alone.
The Royal Horticultural Society (RHS) currently lists ten sections, based on Fernandes (1968), three of which are monotypic (contain only one species), while two others only containing two species. Most species are placed in Pseudonarcissus While infrageneric groupings within Narcissus have been relatively constant, their status (genera, subgenera, sections, subsections, series, species) has not. Some authors treat some sections as being further subdivided into subsections, e.g. Tazettae (3 subsections). These subdivisions correspond roughly to the popular names for narcissi types, e.g. Trumpet Daffodils, Tazettas, Pheasant's Eyes, Hoop Petticoats, Jonquils.
While Webb had simply divided the genus into sections, Mathew found this unsatisfactory, implying every section had equal status. He adapted both Fernandes and Webb to devise a more hierarchical scheme he believed better reflected the interrelationships within the genus. Mathew's scheme consists of three subgenera (Narcissus, Hermione and Corbularia). The first two subgenera were then divided into five and two sections respectively. He then further subdivided two of the sections (subgenus Narcissus section Jonquillae, and subgenus Hermione section Hermione) into three subsections each. Finally, he divided section Hermione subsection Hermione further into two series, Hermione and Albiflorae. While lacking a phylogenetic basis, the system is still in use in horticulture. For instance the Pacific Bulb Society uses his numbering system (see Table II) for classifying species.
Phylogenetics
The phylogenetic analysis of Graham and Barrett (2004) supported the infrageneric division of Narcissus into two clades corresponding to the subgenera Hermione and Narcissus, but does not support monophyly of all sections, with only Apodanthi demonstrating clear monophyly, corresponding to Clade III of Graham and Barrett (see Cladogram), although some other clades corresponded approximately to known sections. These authors examined 36 taxa of the 65 listed then, and a later extended analysis by Rønsted et al. (2008) with five additional taxa confirmed this pattern.
A very large (375 accessions) molecular analysis by Zonneveld (2008) utilising nuclear DNA content sought to reduce some of the paraphyly identified by Graham and Barrett. This led to a revision of the sectional structure, shifting some species between sections, eliminating one section and creating two new ones. In subgenus Hermione, Aurelia was merged with Tazettae. In subgenus Narcissus section Jonquillae subsection Juncifolii was elevated to sectional rank, thus resolving the paraphyly in this section observed by Graham and Barrett in Clade II due to this anomalous subsection, the remaining species being in subsection Jonquillae, which was monophyletic. The relatively large section Pseudonarcissi was divided by splitting off a new section, Nevadensis (species from southern Spain) leaving species from France, northern Spain and Portugal in the parent section. At the same time Fernández-Casas (2008) proposed a new monotypic section Angustini to accommodate Narcissus deficiens, placing it within subgenus Hermione.
While Graham and Barrett (2004) had determined that subgenus Hermione was monophyletic, using a much larger accession Santos-Gally et al. (2011) did not. However the former had excluded species of hybrid origins, while the latter included both N. dubius and N. tortifolius. If these two species are excluded (forming a clade with subgenus Narcissus) then Hermione can be considered monophyletic, although as a section of Hermione, Tazettae is not monophyletic. They also confirmed the monophyly of Apodanthi.
Some so-called nothosections have been proposed, predominantly by Fernández-Casas, to accommodate natural ('ancient') hybrids (nothospecies).
Subgenera and sections
Showing revisions by Zonnefeld (2008)
subgenus Hermione (Haw.) Spach.
(Aurelia (Gay) Baker (monotypic) - merged with Tazettae (2008)
Serotini Parlatore (2 species)
Tazettae de Candolle (16 species) syn. Hermione (Salisbury) Sprengel, in Fernandes' scheme. Incorporating Aurelia (2008)
subgenus Narcissus L.
Apodanthi A. Fernandes (6 species)
Bulbocodium de Candolle (11 species)
Ganymedes (Haworth) Schultes f. (monotypic)
Jonquillae de Candolle (8 species)
Juncifolii (A. Fern.) Zonn. sect. nov. (2008)
Narcissus L. (2 species)
Nevadensis Zonn. sect. nov. (2008)
Pseudonarcissus de Candolle (36 species) Trumpet daffodils
Tapeinanthus (Herbert) Traub (monotypic)
Species
Estimates of the number of species in Narcissus have varied widely, from anywhere between 16 and nearly 160, even in the modern era. Linnaeus originally included six species in 1753. By the time of the 14th edition of the Systema Naturae in 1784, there were fourteen. The 1819 Encyclopaedia Londinensis lists sixteen (see illustration here of three species) and by 1831 Adrian Haworth had described 150 species.
Much of the variation lies in the definition of species, and whether closely related taxa are considered separate species or subspecies. Thus, a very wide view of each species, such as Webb's results in few species, while a very narrow view such as that of Fernandes results in a larger number. Another factor is the status of hybrids, given natural hybridisation, with a distinction between 'ancient hybrids' and 'recent hybrids'. The term 'ancient hybrid' refers to hybrids found growing over a large area, and therefore now considered as separate species, while 'recent hybrid' refers to solitary plants found amongst their parents, with a more restricted range.
In the twentieth century Fernandes (1951) accepted 22 species, on which were based the 27 species listed by Webb in the 1980 Flora Europaea. By 1968, Fernandes had accepted 63 species, and by 1990 Blanchard listed 65 species, and Erhardt 66 in 1993. In 2006 the Royal Horticultural Society's (RHS) International Daffodil Register and Classified List listed 87 species, while Zonneveld's genetic study (2008) resulted in only 36. , the World Checklist of Selected Plant Families accepts 52 species, along with at least 60 hybrids, while the RHS has 81 accepted names in its October 2014 list.
Evolution
Within the Narcisseae, Narcissus (western Mediterranean) diverged from Sternbergia (Eurasia) some time in the Late Oligocene to Early Miocene eras, around 29.3–18.1 Ma, with a best estimate of 23.6 Ma. Later the genus divided into the two subgenera (Hermione and Narcissus) between 27.4 and 16.1 Ma (21.4 Ma). The divisions between the sections of Hermione then took place during the Miocene period 19.9–7.8 Ma.
Narcissus appears to have arisen in the area of the Iberian peninsula, southern France and northwestern Italy, and within this area most sections of the genus appeared, with only a few taxa being dispersed to North Africa at a time when the African and West European platforms were closer together. Subgenus Hermione in turn arose in the southwestern mediterranean and north west Africa. However, these are reconstructions, the Amaryllidaceae lacking a fossil record.
Names and etymology
Narcissus
The derivation of the Latin narcissus () is unknown. It may be a loanword from another language; for instance, it is said to be related to the Sanskrit word , meaning 'hell'. It is frequently linked to the Greek myth of Narcissus described by Ovid in his Metamorphoses, who became so obsessed with his own reflection that as he knelt and gazed into a pool of water, he fell into the water and drowned. In some variations, he died of starvation and thirst. In both versions, the narcissus plant sprang from where he died. Although Ovid appeared to describe the plant we now know as Narcissus there is no evidence for this popular derivation, and the person's name may have come from the flower's name. The Poet's Narcissus (N. poeticus), which grows in Greece, has a fragrance that has been described as intoxicating. This explanation is largely discredited due to lack of proof. Pliny wrote that the plant '''' ('named narcissus from narce, not from the legendary youth'), i.e. that it was named for its narcotic properties ( , 'I grow numb' in Greek), not from the legend. Furthermore, there were accounts of narcissi growing, such as in the legend of Persephone, long before the story of Narcissus appeared (see Greek culture). It has also been suggested that daffodils bending over streams evoked the image of the youth admiring his own reflection in the water.
Linnaeus used the Latin name for the plant in formally describing the genus, although Matthias de l'Obel had previously used the name in describing various species of Narcissi in his Icones stirpium of 1591, and other publications, as had Clusius in Rariorum stirpium (1576).
The plural form of the common name narcissus has caused some confusion. British English sources such as the Shorter Oxford English Dictionary give two alternate forms, narcissi and narcissuses. In contrast, in American English the Merriam-Webster Dictionary provides for a third form, narcissus, used for both singular and plural. The Oxford dictionaries only list this third form under American English, although the Cambridge Dictionary allows of all three in the same order. However, Garner's Modern American Usage states that narcissi is the commonest form, narcissuses being excessively sibilant. For similar reasons, Fowler prefers narcissi in British English usage. Neither support narcissus as a plural form. Common names such as narcissus do not capitalise the first letter in contrast to the person of that name and the Latin genus name.
The name Narcissus (feminine Narcissa) was not uncommon in Roman times, such as Tiberius Claudius Narcissus, a Roman official in Claudius' time, an early New Testament Christian in Rome and later bishops and saints.
Daffodil
The word daffodil was unknown in the English language before the sixteenth century. The name is derived from an earlier affodell, a variant of asphodel. In classical Greek literature the narcissus is frequently referred to as the , such as the meadows of the Elysian fields in Homer (see Antiquity). Asphodel in turn appears to be a loanword coming from French via Mediaeval Latin from Classical Latin and ultimately the Greek (). The reason for the introduction of the initial d is not known, although a probable source is an etymological merging from the Dutch article , as in , or English the, as th'affodil or t'affodil, hence daffodil, and in French and to form and .
From at least the 16th century, daffadown dilly and daffydowndilly have appeared as playful synonyms of the name. In common parlance and in historical documents, the term daffodil may refer specifically to populations or specimens of the wild daffodil, N. pseudonarcissus. H. N. Ellacombe suggests this may be from Saffon Lilly, citing Prior in support, though admittedly conjectural.
Lady Wilkinson (1858), who provides an extensive discussion of the etymology of the various names for this plant, suggests a very different origin, namely the Old English word (that which cometh early), citing a 14th-century (but likely originally much earlier) manuscript in support of this theory, and which appears to describe a plant resembling the daffodil. Ellacombe provides further support for this from a fifteenth century English translation of Palladius that also refers to it.
Jonquil
The name jonquil is said to be a corruption via French from the Latin meaning 'rush-leaf' (Juncaceae) and its use is generally restricted to those species and cultivars which have rush like leaves, e.g. N. juncifolius.
Other
A profusion of names have attached themselves in the English language, either to the genus as a whole or to individual species or groups of species such as sections. These include narcissus, jonquil, Lent lily, Lenten lily, lide lily, yellow lily, wort or wyrt, Julians, glens, Lent cocks, corn flower, bell rose, asphodel, Solomon's lily, gracy day, haverdrils, giggary, cowslip, and crow foot''.
References
Notes
Bibliography
Antiquity
Mediaeval and Renaissance
Eighteenth and nineteenth centuries
(also available as pdf)
Modern
Societies and organisations
Narcissus
Narcissus | Taxonomy of Narcissus | [
"Biology"
] | 4,990 | [
"Taxonomy (biology)"
] |
73,007,678 | https://en.wikipedia.org/wiki/SaTScan | SaTScan is a software tool that employs scan statistics for the spatial and temporal analysis of clusters of events. The software is trademarked by Martin Kulldorff, and was designed originally for public health and epidemiology to identify clusters of cases in both space (geographical location) and time and to perform statistical analysis to determine if these clusters are significantly different from what would be expected by chance The software provides a user-friendly interface and a range of statistical methods, making it accessible to researchers and practitioners. While not a full Geographic Information System, the outputs from SaTScan can be integrated with software such as ArcGIS or QGIS to visualize and analyze spatial data, and to map the distribution of various phenomena.
Analysis
SaTScan employs scan statistics to identify clusters of space and time phenomena. Scan statistics use regular shapes (usually circles) of varying sizes to evaluate a study area. Within each circle, the software computes if the phenomena within the circle is significantly different than expected compared to the area outside the circle.
SaTScan can analyze data retrospectively or prospectively. It can look at the data spatially, temporally, or simultaneously incorporate both space and time. SaTScan can incorporate numerous probability models, including Poisson distribution, Bernoulli distribution, Monte Carlo method, and multinomial distribution. Using these, it can look for areas of higher and lower occurrences of phenomena than expected.
Results are output into a variety of formats, including ESRI Shapefile, HTML, and KML.
History
SaTScan was developed by a group of epidemiologists and statisticians led by Martin Kulldorff, a Swedish biostatistician professor of medicine at Harvard Medical School. Version 1.0 of the software was first released in 1997 and has since become a widely used tool in the field of public health research and practice.
SaTScan was developed in response to a growing need for sophisticated tools to analyze disease outbreaks. Before the development of SaTScan, few tools were available that could effectively analyze the spatial and temporal patterns of disease, making it difficult for public health authorities to respond effectively to outbreaks.
Since its release, SaTScan has been used in many public health research studies, including infectious diseases, cancers, and other conditions. Public health authorities and disease surveillance systems have also adopted the software in many countries, and it has broad applications for other types of data.
SaTScan was used extensively by researchers during the COVID-19 pandemic.
Applications
Epidemiology
SaTScan was originally developed for epidemiology and public health. Since its release, SaTScan has been used in many public health research studies involving GIS, including infectious diseases, cancers, and other conditions. Public health authorities and disease surveillance systems have also adopted the software in many countries.
Agriculture
SaTScan can identify areas of high pest or disease risk, informing crop and livestock management and disease control efforts.
Astronomy
SaTScan can also be adapted and applied to certain astronomical studies, particularly those that involve analyzing spatial and temporal patterns in astronomical data. For example, SaTScan could identify clustering patterns in the distribution of galaxies or other astronomical objects, such as stars.
Criminology
SaTScan can identify hot spots and patterns in crime data, which can assist law enforcement agencies in allocating resources and developing crime reduction strategies.
Environmental monitoring
SaTScan can identify areas of environmental concern, such as high levels of air pollution or water contamination.
Wildlive surveillance
SaTScan can identify areas of high risk for wildlife diseases, which can inform disease management and conservation efforts.
See also
AM/FM/GIS
Automotive navigation system
Collaborative mapping
Comparison of GIS software
Concepts and Techniques in Modern Geography
Counter-mapping
Distributed GIS
GISCorps
GIS Day
Integrated Geo Systems
Internet GIS
List of GIS data sources
List of GIS software
Map database management
Participatory GIS
Quantitative geography
Technical geography
Web GIS
References
Free GIS software
Spatial analysis
Health informatics
Public health
SaTScan official website | SaTScan | [
"Physics",
"Biology"
] | 802 | [
"Health informatics",
"Spatial analysis",
"Space",
"Spacetime",
"Medical technology"
] |
73,008,142 | https://en.wikipedia.org/wiki/Wes%20Hildreth | Edward Wesley Hildreth III (known professionally as Wes Hildreth; born August 17, 1938) is an American geologist affiliated with the U.S. Geological Survey (USGS) and the California Volcano Observatory. Employed by the USGS since 1977 as a research geologist, Hildreth is a Department of the Interior senior scientist. Described in Wired as "one of the great volcanologists/petrologists of our time," his work in the fields of volcanology, petrology, and geologic mapping has been recognized with the and Thorarinsson Medal, and with fellowship in the Geological Society of America (GSA) and the American Geophysical Union. Hildreth's body of research includes work on the volcanic history of the Cascade Range, magmatism of the Long Valley Caldera, and mapping of mountain regions in the Andes.
Early life and education
Wes Hildreth, full name Edward Wesley Hildreth III, was born on August 17, 1938 in Newton, Massachusetts, and is of Scottish ancestry. His parents—a housewife from an upper class family and a middle class retail store manager—had married earlier that year. Wes grew up "bicoastal", and has lived most of his life in either Greater Boston or the San Francisco Bay Area; he attended schools in both California and Massachusetts, and graduated from Tamalpais High School as salutatorian in 1956. Hildreth ran the Dipsea Race in 1955, while a student at Tamalpais.
Hildreth attended Harvard College, where he majored in geology with a minor in government. While at Harvard, he was a cross country runner for the Harvard Crimson. He received a Detur Book Prize (awarded to sophomores with high academic standing) in 1958. Between his sophomore and junior years, he joined an army reserve unit and trained for six months at Fort Ord, earning the distinction "Outstanding Soldier of the Cycle" in 1959. In 1960, he placed 29th in the 1960 Boston Marathon, and was elected to Phi Beta Kappa. Hildreth graduated with a Bachelor of Arts degree cum laude in 1961. After graduating, he received a scholarship to travel the world, and he did for ten years, picking up a job as a naturalist for the National Park Service.
Hildreth started graduate school, but dropped out under the domestic pressure of the Vietnam War. He later returned to graduate studies: under the advisorship of Ian S. E. Carmichael, Charles M. Gilbert, and Herbert R. Shaw, Hildreth received a Doctor of Philosophy degree from the University of California, Berkeley in 1977, staying at Berkeley after graduation to complete postdoctoral work with Carmichael.
Personal life
In 1964, Hildreth married a woman named Nancy (now Nancy Brown, married to Roger Brown). Wes and Nancy are separated, but appeared in an oral history interview together in 2016. Hildreth met Gail Mahood while a student at Berkeley, and they were married in 1982. The two are both geologists, and have published papers together.
Career and research
Starting in 1966, 5 years after his bachelor's degree was completed, Hildreth worked as a naturalist for the National Park Service. That same year, he conducted research at Muir Woods National Monument, and published a report on the history of the area. During his time with the Park Service, he had stints visiting Death Valley and the Olympic Mountains. He left his position in 1970, later becoming an instructor at the University of California, Berkeley, where he worked from 1973 to 1975. In 1977, Hildreth received his Ph.D. from Berkeley; he joined the U.S. Geological Survey as a research geologist in the same year.
Hildreth's interest in the Panamint Ranges led him to return to Death Valley and the Bishop Tuff while studying at Berkeley. His analysis of the tuff was a major contribution to the field, and since that time he has published on a wide array of geoscience topics, including volcanology, petrology, and geologic mapping, with a focus on continental formations such as calderas. In the 1970s, Hildreth saw a start to his career by studying the Bishop Tuff and Long Valley Caldera, and also by collaborating with Bob Christiansen on research in Yellowstone National Park. His early research also helped solidify the scientific consensus that there is compositional zoning of magma reservoirs.
Prior to 1980, Hildreth's primary research partner was David A. Johnston, though he was killed by the 1980 eruption of Mount St. Helens. Since that summer, much of Hildreth's research has been conducted with Judy Fierstein, fellow USGS geologist. Their collaboration began in 1980, when Hildreth took Fierstein—then a fresh college graduate—to the Valley of Ten Thousand Smokes in Katmai National Park and Preserve to conduct field research. Hildreth had been studying the geology of Katmai since 1976, but this was Fierstein's first experience in the park. In 2012, Hildreth and Fierstein published a report to commemorate the centennial of the 1912 eruption of Novarupta. The pair have also published research on other volcanoes within the park, including Kaguyak Caldera. Their enduring partnership has proved fruitful, with them both becoming vital to each other's research. In 2019, the duo won the Florence Bascom Geologic Mapping Award, conferred by the Geological Society of America, for their mapping efforts in Alaska, Chile, and the western United States.
In 1979, Hildreth published the seminal paper on Bishop Tuff studies. Subsequent works by him have also helped establish a greater understanding of the Bishop Tuff and its origins. In the Andes, his work has made him a leading expert on the geology of Laguna del Maule. As of 2024, Hildreth is a staff member of the USGS California Volcano Observatory and works out of Menlo Park, California.
Professional service
Hildreth has served as an associate editor of Andean Geology since 1987, a role he previously held at the Journal of Geophysical Research from 1984 to 1986. From 1991 to 2001, he also served on the editorial board of the Bulletin of Volcanology. Hildreth also participates in public events—he was a participant in the 2005 GSA field forum in the Sierra Nevada and the White–Inyo Mountains. He again participated in a GSA field forum in 2009, in Bishop, California, which was adapted into a special issue of Lithosphere. In July 2016, Hildreth and Fierstein hosted an interpretive lecture and hike at Devils Postpile National Monument.
Awards and honors
At the May 1985 meeting of the Geological Society of America, Hildreth was elected a fellow of the society. In December of 1985, he was awarded the (named for Norman L. Bowen) of the American Geophysical Union for his geochemical and petrologic studies of the Bishop Tuff, Novarupta, and Yellowstone. Hildreth became a fellow of the union in January 1995. In 2004, Hildreth was awarded the Thorarinsson Medal (named for Sigurdur Thorarinsson) for his many contributions to volcanology, including eruptive and petrological studies at Mount Baker and Mount Adams in the Cascade Range, Mount Katmai in Alaska, and the Yellowstone Caldera; mapping of volcanic calderas in the Andes; and magmatic studies at Long Valley. The GSA awarded Hildreth and Fierstein the 2019 Florence Bascom Geologic Mapping Award (named for Florence Bascom) for their mapping efforts at Adams, Baker, Katmai, Laguna del Maule, and Long Valley as well as the Three Sisters, Simcoe Mountains, Pantelleria, Quizapu–Descabezado, and Mammoth Mountain.
References
External links
Wes HildrethStaff Profiles, U.S. Geological Survey
Living people
1938 births
Scientists from Newton, Massachusetts
Scientists from the San Francisco Bay Area
Tamalpais High School alumni
Harvard College alumni
University of California, Berkeley alumni
University of California, Berkeley faculty
National Park Service personnel
United States Geological Survey personnel
Fellows of the American Geophysical Union
Fellows of the Geological Society of America
American volcanologists
American geochemists
American cartographers
20th-century American geologists
21st-century American geologists | Wes Hildreth | [
"Chemistry"
] | 1,731 | [
"Geochemists",
"American geochemists"
] |
73,008,575 | https://en.wikipedia.org/wiki/Hunter%27s%20Point%20crane | The Hunter's Point crane is a gantry crane located at the naval shipyard in Hunters Point, San Francisco. When it was built, in 1947 to repair battleships and aircraft carriers, it was the largest crane in the world.
It has a capacity and was completed at the site by the American Bridge Company.
When it was first built, it was used to lift 630 tons, which the San Francisco Chronicle reported at the time was the heaviest load ever lifted.
In 1959, it was used for Operation Skycatch, where dummy Polaris missiles were fired and caught via a string of arresting cables, before being lowered to the ground for testing. Previous versions of the test had the missiles flung out into the bay and retrieved from the ocean floor.
A large trapezoidal frame was erected atop the gantry crane for the UGM-73 Poseidon missile test facility; the structural members were lifted by Marine Boss in 1967. The addition of the frame brought the total height of the crane to nearly . The crane dominates the landscape in the area, as it is easily visible from miles around.
Today, the site where the crane is located is a superfund site due to contamination by the military, and there is no public access.
References
Cranes (machines) | Hunter's Point crane | [
"Engineering"
] | 255 | [
"Engineering vehicles",
"Cranes (machines)"
] |
73,009,366 | https://en.wikipedia.org/wiki/Cement%2C%20California | Cement, California is a mining and manufacturing ghost town in Solano County now enveloped within the boundaries of the United States city of Fairfield. Cement was established as a company town at the turn of the 20th century and it quickly became a boomtown. It was founded and owned by the Pacific Portland Cement Company, who produced Portland cement that was bagged and labeled under the company's "Golden Gate" trademarked brand. It was shuttered in 1927, structures and equipment were auctioned off, and its remains are now in ruins or were moved away.
History
The town of Cement was established in 1902 by the Pacific Portland Cement Company and was originally named after the large deposits of high-quality limestone rock deposits found in the area. This limestone was ideal for the lime that was needed for the production of Portland cement produced by the company at Cement.
Enormous conveyors, rock crushers, tube cement mills, and rotary kilns were created to process the raw quarried limestone.
The town also had its own open pit clay and gypsum mines with clay and gypsum being necessary components in the finished Portland cement the plant produced.
The establishment of the cement industry in Cement brought a large influx of workers to the area, and the town quickly grew into a thriving community of people with a strong economy. It became more populous than the three nearest cities combinedFairfield, Vacaville and Suisun City.
The cement industry was the lifeblood of Cement for many years, and the town prospered as a result. The population of the town grew steadily to 500 people, and businesses and services were established to support the needs of the growing community. This included the three-story Golden Gate Hotel, hospital, restaurant, bar, livery stable, post office, telephone exchange, park, baseball diamond, general store, fire station, churches, and a grade school.
Railway
The town owners constructed a single-track standard-gauge steam railway to get products and supplies to and from Cement and Tolenas which were away from each other. The company had a total of of track including yard and side tracks. The railway's name was .
Decline
The prosperity of Cement was not to last. As the limestone deposits were depleted, the industry in Cement began to decline, and the town's economy began to suffer.
Over time, the population of Cement continued to drop, and many of the town's businesses and services were forced to close. The town was finally sold off in 1927 for only a few thousand dollars. The once-thriving town became a shadow of its former self, and today it is a ghost town. The ruins of the town, including remnants of the old cement mill and the foundations of abandoned homes and buildings, stand as a testament to the once-prosperous community that was a center of the cement industry in California. The most prominent and visible concrete ruin on Cement's hillside is large and referred to locally as "The Castle." The Castle can be seen all the way from Interstate 80 in Fairfield.
Present day
Despite its demise, Cement is an important part of California's history and culture. The remaining ruins serve as a reminder of the impact that the cement industry had on the region and the lives of its residents. Cement still interests people wondering about the history of the cement industry, the American West, the ghost town, and its past.
Cement is privately owned land and the owner's permission is required to visit the property that is approximately .
See also
Le Hunt, Kansas
Lime, Oregon
List of ghost towns in California
List of ghost towns by country
References
More reading
Ghost towns of California: your guide to the hidden history and Old West haunts of CaliforniaPhilip Varney, comprehensive overview of the history of ghost towns in California, (2012)
External links
Comprehensive information about ghost towns in the U.S.
"Dusty Memories and a Castle on the Hill"
KPIX Channel 5 Eye on the Bay segment featuring Cement (2009)
"Solano County Stone Quarries"
Town of Cement
Ghost towns in California
History of Solano County, California
Populated places established in 1902
1902 establishments in California
Cement
California
Limestone industry | Cement, California | [
"Chemistry",
"Engineering"
] | 835 | [
"Lime kilns",
"Kilns"
] |
73,012,861 | https://en.wikipedia.org/wiki/Daqi-1 | Daqi-1 or Atmospheric Environment Monitoring Satellite is a Chinese satellite which was launched on 15 April 2022 to study the atmosphere of the Earth. Its Aerosol and Carbon Detection Lidar (ACDL) instrument was thought to be the most likely cause of a green laser light display observed over Hawaii on 28 January 2023 by the Subaru Telescope, although initially thought to be from a remote-sensing altimeter satellite ICESat-2.
References
Earth observation satellites of China | Daqi-1 | [
"Astronomy"
] | 96 | [
"Outer space stubs",
"Outer space",
"Astronomy stubs"
] |
73,013,274 | https://en.wikipedia.org/wiki/Criticism%20of%20space%20exploration | Criticism of space exploration encompasses various arguments against investing in space programs and missions. Opponents point to the substantial financial costs, suggesting that funds allocated for space exploration could be better spent addressing urgent issues on Earth, such as poverty, healthcare, education, and environmental degradation. Critics express concerns about risks to human life, environmental impacts like potential contamination of celestial bodies, and the possibility of militarizing space, which could exacerbate geopolitical tensions. These critiques reflect the ongoing debate over resource allocation, technological priorities, and the responsibilities of humanity both on Earth and in outer space.
History
Apollo missions
In 1963, years before the 1969 Apollo 11 Moon landing, German-American critical theorist Hannah Arendt argued:
Throughout the 1960s, Students for a Democratic Society organized anti-NASA protests on college campuses. Sit-ins occurred at Columbia University's Pupin Physics Laboratories and MIT's Instrumentation Laboratory, as both conducted NASA research which was implemented by the United States military in Vietnam. In July 1969, civil rights leader Ralph Abernathy organized a protest at Cape Canaveral (then Cape Kennedy) to oppose the "inhuman priority" of space exploration over tackling poverty and racism. When addressing a white suburban audience filled with space and electronic experts, Unitarian Church Rev. David Eaton, said that "[t]he $23 billion we've spent going to the Moon has stolen money the black man needs for job retraining and schools."
Contemporary arguments
Climate change
Amitai Etzioni wrote in 2018 that space colonization "brings with it an unavoidable subtext of despair", distracting from efforts to halt anthropogenic climate change, arguing that "any serious Mars endeavor will inevitably cut into the drive to save Mother Earth". Some studies suggest that the projected increase in space travel will damage the ozone layer. A single rocket launch produces 300 tonnes of carbon dioxide, staying longer in the upper atmosphere than emissions caused by airplanes or jets. Thomas Fink, however, argues the long-term benefits of space science offset the ecological risks.
Wastefulness
Arthur M. Schlesinger Jr. condemned space exploration, labeling it as wasteful. In the lead up to the Apollo program, Congressmen voiced doubts about the costliness of the missions. In 1977, Governor of California Jerry Brown was criticized for prioritizing space programs over addressing social issues.
Political
Alexis C. Madrigal, writing in the Los Angeles Sentinel in 2012, said that
Haris Durrani, writing in The Nation, argued in 2019 that "[s]paceflight almost invariably involves activities that directly subjugate marginalized peoples". Mark R. Royce, writing for Providence magazine, argued in 2020 that rather than being a non-partisan, inoffensive, and humanistic endeavor, space exploration is "largely irrational, originating at the intersection of the early Cold War arms race, the mass hysteria of the Red Scare, and the utopian worship of technical progress that characterized the mid-twentieth century." Gabrielle Cornish argued in 2019 that the moon landing was "at its core, a territorial conquest" in the context of the Cold War.
Linguistic
Several critics have likened space exploration to settler-colonialism and imperialism, with critics such as Deondre Smiles arguing that the exploration of space could lead to further colonization on Earth, pointing to the controversial construction of observatories in Mauna Kea. Sociologist Zuleyka Zevallos at Swinburne University has criticized the language used within and around space science, writing that "there is no democratic way to colonize other lands" and that "It is about profit, and profit always marginalizes minorities". In contrast, Robert Zubrin of the Mars Society responds that it is different from comparing the history of colonialism on Earth with the establishment of colonies on Mars.
From within astrophysics
Fulbright scholar and Mars colonization advocate Zahaan Bharmal outlined three hypothetical arguments against human colonization of Mars: (1) that humans will contaminate Mars, (2) that robots have inherent advantages over humans in space exploration, and (3) that issues like climate change, overpopulation, and nuclear war should be prioritized over colonization. While broadly supportive of Mars colonization, Bharmal argues that humans "are perhaps not ready to go to Mars."
Public opinion
Contrary to the common misconception that the American space program in the 60s had a wide base of support, unifying America, belief that the Apollo program was worth the time and money invested peaked at 51% for a few months after the 1969 Moon landing, and was otherwise fluctuating between 35-45%.
See also
Criticism of science
Notes
References
Space exploration | Criticism of space exploration | [
"Astronomy"
] | 951 | [
"Space exploration",
"Outer space"
] |
73,013,519 | https://en.wikipedia.org/wiki/Construction%20amnesty | Construction amnesty, also known as reconstruction peace, building permit forgiveness and zoning reconciliation (Turkish: imar barışı or imar affı), is any set of Turkish law to register and legalize nominally illegal construction. Amnesty is (retroactively) granted to buildings without any planning permission such as gecekondus, and to constructions that disregarded official building codes including fire and earthquake safety regulations. Zoning amnesties generally are awarded by authorities for short term economic and political gain. Amnesty laws have been described as a populist method of soliciting votes by politicians, as their timing often coincided multiple times with various Turkish elections that took place throughout the past couple of decades.
History
The first official zoning amnesty plan was accepted by the parliament in 1984, though it was stated that the government had implemented similar policies in the past going back to late 1940's. The has been a total of 19 zoning amnesties since 1948.
The last construction amnesty in Turkey was accepted by the government in May 2018, five weeks before the 2018 Turkish presidential election, registering and giving occupancy permits (Turkish: yapı kayıt belgesi) to more than 3 million buildings that were not built according to regulations. That amnesty was opposed by Garo Paylan, a lawmaker of the Peoples' and Democracy Party (HDP) at the time. The amnesty become law on 4 June 2018 by being published in the Official Gazette of the Republic of Turkey. As of 2022 more than 7 million buildings have got permits through the 2018 amnesty, 5.8 million of them being residential ones.
In July 2022 a new amnesty plan was proposed by Mustafa Destici, leader of the BBP, which is a member of the People's Alliance. Grand National Assembly of Turkey sent the plan to the internal Committee on Public Works, Reconstruction, Transportation and Tourism for further review in October 2022. The new plan was seen as a move to gain support for the incoming 2023 Turkish presidential election.
Criticism
Since their implementation construction amnesties were criticized by numerous organizations such as Union of Chambers of Turkish Engineers and Architects. After the 2020 Aegean Sea earthquake and 2023 Turkey–Syria earthquake brought the topic back on the public discourse.
References
Regulation in Turkey
Pardons
Construction in Asia
Construction law
Illegal housing | Construction amnesty | [
"Engineering"
] | 470 | [
"Construction",
"Construction law"
] |
73,013,926 | https://en.wikipedia.org/wiki/V773%20Tauri | V773 Tauri is a young, multiple star system in the central region of Taurus, an equatorial constellation. This is a T Tauri-type variable star that ranges in apparent visual magnitude from 10.59 down to 10.95, which is too faint to be viewed with the naked eye. Based on various estimates, the system is located at a distance of approximately 433 light years from the Sun. It lies near the dark cloud Lynds 1495.
Hierarchy of orbits
This system was identified as a T Tauri star by A. E. Rydgren and associates in 1974. Radio emission was detected from this source in 1983. In 1993, it was discovered to be a double star with an angular separation of about : the two components are designated A and B. Component A was found to be a double-lined spectroscopic binary with an orbital period of 51 days. In 2003, a third member of this group was located, component C, at a separation of from component A.
Orbital solutions for the A–B pair provide an unexpectedly high dynamic mass of for component B, suggesting it too may be a binary system. A single star with that much mass would have 17 times the luminosity of the Sun, which is inconsistent with the observed optical luminosity. Photometry of component B suggests it is experiencing extinction from dust along the line of sight. The component is variable in the K band, which is consistent with clumps or clouds of dust in orbit.
In 2010, an extended eclipse was observed in the V773 Tauri system. This was interpreted as a circumbinary disk of component B passing in front of component A. The eclipse obscured 70% of the emission from component A and lasted 150 days.
References
Further reading
T Tauri stars
Circumstellar disks
Multiple star systems
Taurus (constellation)
022468
019762
Tauri, V773 | V773 Tauri | [
"Astronomy"
] | 398 | [
"Taurus (constellation)",
"Constellations"
] |
73,015,595 | https://en.wikipedia.org/wiki/Virtual%20photon | Virtual photons are a fundamental concept in particle physics and quantum field theory that play a crucial role in describing the interactions between electrically charged particles. Virtual photons are referred to as "virtual" because they do not exist as free particles in the traditional sense but instead serve as intermediate particles in the exchange of force between other particles. They are responsible for the electromagnetic force that holds matter together, making them a key component in our understanding of the physical world.
Virtual photons are thought of as fluctuations in the electromagnetic field, characterized by their energy, momentum, and polarization. These fluctuations allow electrically charged particles to interact with each other by exchanging virtual photons. The electromagnetic force between two charged particles can be understood as the exchange of virtual photons between them. These photons are constantly being created and destroyed, and the exchange of these virtual photons creates the electromagnetic force that is responsible for interaction between charged particles.
Virtual photons can be classified into positive and negative virtual photons. These classifications are based on the direction of their energy and momentum and their contribution to the electromagnetic force.
If virtual photons exchanged between particles have a positive energy, they contribute to the electromagnetic force as a repulsive force. This means that the two charged particles are repelled from each other and the electromagnetic force pushes them apart. On the other hand, if the virtual photons have a negative energy, they contribute to the electromagnetic force as an attractive force. This means that the two charged particles are attracted to each other and the electromagnetic force pulls them towards each other.
It is important to note that positive and negative virtual photons are not separate particles, but rather a way of classifying the virtual photons that exist in the electromagnetic field. These classifications are based on the direction of the energy and momentum of the virtual photons and their contribution to the electromagnetic force.
Virtual photons can have a range of polarizations, which can be described as the orientation of the electric and magnetic fields that make up the photon. The polarization of a virtual photon is determined by the direction of its momentum and its interaction with the charges that emit or absorb it. The range of polarizations for virtual photons can be compared to the range of colors for visible light, with each polarization corresponding to a specific orientation of the electric and magnetic fields.
Virtual photons are said to be "off-shell", which means that they do not obey the usual relationship between energy and momentum that applies to real particles. Real photons must always have energy equal to the speed of light times their momentum, but virtual photons can have any energy that is consistent with the uncertainty principle. This allows virtual photons to carry a wide range of energies, even if they are not physically real.
Virtual photons are responsible for Lamb shift, which is a small shift in the energy levels of hydrogen atoms caused by the interaction of the atom with virtual photons in the vacuum.
They are also responsible for the Casimir effect, which is the phenomenon of two uncharged metallic plates being attracted to each other due to the presence of virtual photons in the vacuum between them. The attractive force between the plates is caused by a difference in the density of virtual photons on either side of the plates, which creates a net force that pulls them together.
References
Quantum field theory
Photons | Virtual photon | [
"Physics"
] | 668 | [
"Quantum field theory",
"Quantum mechanics"
] |
73,015,816 | https://en.wikipedia.org/wiki/Epirus%20Leonidas | The Leonidas is a high-power microwave (HPM) weapon developed to disable unmanned aerial vehicle (UAV) swarms. It was named after Leonidas of Epirus.
Design and development
Epirus was founded in 2018 to enter the counter-drone market and it unveiled the Leonidas in 2020. The threat of small drones, especially cheap consumer models, is difficult to counter in large numbers using traditional kinetic means. Against regular air defenses, cheap drones can be deployed in large numbers to overwhelm a defender or force them to expend more expensive interceptors. Leonidas is designed as a directed energy weapon that fires electromagnetic pulse (EMP) beams to disable electronics. The system is able to pick individual targets or cover a large area in wide beam mode to affect any electronic device that passes through. While it was intended to be used against airborne drone threats, it has the ability to knock out ground vehicles and sea vessels; it works against any electronics, and has been demonstrated to disable an outboard ship motor.
Due to its use of gallium nitride transistors previously used in radars instead of magnetron vacuum tubes, Leonidas can maintain a durable microwave beam while being smaller and requiring less power. As a directed EMP, the system has advantages over other DEWs; lasers can only be used against one target at a time while an HPM can focus on a large area, and it works against autonomous UAVs with no link back to an operator that radio jamming would be ineffective against. Because it is software-based, it is able to discriminate between enemy and friendly aircraft, allowing it to take down enemy drones while enabling friendly ones to operate in the same vicinity. The original configuration was as a towed trailer. In October 2021, Epirus and General Dynamics announced they were teaming to integrate Leonidas onto the Stryker to provide mobile short-range air defense. Epirus unveiled the Leonidas Pod in February 2022 capable of being carried by a heavy-lift UAV. The Leonidas Expeditionary Directed Energy Counter-Swarm (ExDECS) was unveiled in September 2024 as a small version for mobile forces such as the U.S. Marine Corps.
On 23 January 2023, Epirus was awarded a $66.1 million contract by the Rapid Capabilities and Critical Technologies Office (RCCTO) to deliver the Leonidas to the U.S. Army as part of the Indirect Fire Protection Capability-High-Power Microwave (IFPC-HPM) program after outperforming six other systems. Four prototypes were to be produced by 2024 and then transitioned to a program of record in 2025. Epirus announced on 1 November 2023 that the first prototype had been delivered and all four were delivered by March 2024. Some of the IFPC-HPM prototypes are to be deployed to CENTCOM to see how they perform in a real-world environment.
See also
Counter-electronics High Power Microwave Advanced Missile Project
THOR (weapon)
Radio Frequency Directed Energy Weapon
References
External links
Epirus Inc.
Directed-energy weapons
Electromagnetic radiation | Epirus Leonidas | [
"Physics"
] | 628 | [
"Electromagnetic radiation",
"Physical phenomena",
"Radiation"
] |
73,016,427 | https://en.wikipedia.org/wiki/LGA%207529 | LGA 7529 is a zero insertion force flip-chip land grid array (LGA) socket designed by Intel which supports the Sierra Forest line of E-core only Xeon processors, designed for heavily multithreaded cloud workloads, as well as the Granite Rapids line of P-core only Xeon microprocessors, designed for mainstream usage. The socket is also expected to support the mainstream successor to Granite Rapids, Diamond Rapids. The first pictures of the Intel Birch Stream platform were posted on January 31, 2023, by Yuuki_Ans. They showcased a dual LGA 7529 socket engineering sample motherboard.
The Birch Stream platform is expected to support 12 channels of DDR5 memory per socket, for a total of 24 channels of DDR5 memory on a dual socket system.
At OCP Summit 2023, Intel announced that Sierra Forest would be targeting a 1H 2024 launch. The first line of Sierra Forest SKUs launched was the 6700E series, which uses the LGA 4710 socket, rather than the LGA 7529 socket.
Intel launched the first processors to use the LGA 7529 socket on September 24, 2024, with their launch of their Granite Rapids line of CPUs. This product line has two classes of CPUs: one using the twelve-channel LGA 7529 socket, referred to as the Xeon 6900P series, and the other using the smaller eight-channel LGA 4710 socket, referred to as the Xeon 6700P series.
References
Intel CPU sockets | LGA 7529 | [
"Technology"
] | 319 | [
"Computing stubs",
"Computer hardware stubs"
] |
73,019,349 | https://en.wikipedia.org/wiki/Fendt%20700%20Vario | Fendt 700 Vario is a series of tractors made by the manufacturer of agricultural machinery, Fendt. Since the introduction of the first 700 Vario model in 1989, seven generations of the series have been released. The 700 Vario is the manufacturer's best-selling tractor series. The latest generation, the Fendt 700 Vario Gen7, has been available on the market since the summer of 2022.
Series
The 700 Vario series has been available since 1998. Among the larger Fendt models, 800 Vario to 1100 Vario MT and the compact machines of the 200 Vario, 300 Vario and 500 Vario series, the 700 Vario is considered particularly versatile. The series is the best-selling model of Fendt and the most popular tractor in Germany.
Since its official presentation in 1998, the drive, technology and equipment of the Fendt 700 Vario have been consistently further developed. In total, there are seven generations of the series. Each generation includes four to six different models, which mainly differ in performance and horsepower. Currently, the 700 Vario Gen6 models and the tractors of the latest generation 700 Vario Gen7 are still being produced. Due to their durability and long lifespan, older Fendt 700 generations are still available as used machines on the market.
Fendt pursues the approach of combining a comfortable and user-friendly operation with a versatile range of functions with the 700 Vario series. The innovative operating system Variotronic, which was introduced with the introduction of the first 700 Vario generation in 1998, has been awarded internationally.
Since 2011, all tractors of the fourth generation have been equipped with Fendt Efficient Technology (FET) and the VisioPlus cab for safe and comfortable work. In 2020, the FendtOne operating system was introduced with the sixth generation. In response to global demand, the available track widths of the tractor models have been adjusted. Also, all Fendt 700 Vario models currently built comply with the European exhaust emission standard stage V. On July 25, 2024, the 100,000th Fendt 700 Vario rolled off the production line in Marktoberdorf, proving the succes of the tractor series.
Generations and Models
The latest generation
The seventh generation series includes five models (720, 722, 724, 726 and 728 Vario) with a power range of 149 – 208 kW and 203 - 303 HP. As with previous generations, the focus of the Gen7 is a low power-to-weight ratio and high-performance range—however, the new models have been visually and technically overhauled. For the first time, a Deutz engine was not used, but a 6-cylinder engine by AGCO Power with 7.5 litres of displacement and 1,220 Nm. The fans, transmission and drive have also been renewed in the Gen7 models. The Fendt VarioDrive drive for automatic shifting of the driving ranges from the 1000 Vario series has now been integrated into the new 700 Vario models.
The compact cooling unit with the Concentric Air System (CAS) cooling concept is a new feature. The slim design allows for a large steering angle and makes the Fendt 700 Vario Gen7 particularly manoeuvrable. All models also have integrated hood and rear cameras as well as the integrated safety concept Fendt Stability Control, which reduces side inclination and swaying even with heavy loads. In addition, there is an integrated tire pressure control VarioGrip.
From late 2023, the Fendt 700 Vario Gen7 will be optionally available with a new trailer brake assistant.
External links
Fendt 700 Vario on the homepage of the manufacturer
References
Tractors | Fendt 700 Vario | [
"Engineering"
] | 753 | [
"Engineering vehicles",
"Tractors"
] |
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