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74,265,399 | https://en.wikipedia.org/wiki/Private%20cloud%20computing%20infrastructure | Private cloud computing infrastructure is a category of cloud computing that provides comparable benefits to public cloud systems, such as self-service and scalability, but it does so via a proprietary framework. In contrast to public clouds, which cater to multiple entities, a private cloud is specifically designed for the requirements and objectives of one organization.
Definition
A private cloud computing infrastructure constitutes a distinctive model of cloud computing that facilitates a secure and distinct cloud environment where only the intended client can function. It can either be physically housed in the organization's in-house data center or be managed by a third-party provider. In a private cloud, the infrastructure and services are always sustained on a private network, and both the hardware and software are devoted exclusively to a single organization.
History
The concept of private cloud infrastructure started to take shape around the mid-2000s, coinciding with the rise of other cloud computing forms. It came into existence as a solution to the shortcomings of public clouds, particularly concerns over data control, security, and network performance. IT departments began to mirror the automation and self-service features of the public cloud in their data centers. Over time, these services became more advanced, and private cloud technology has been refined to address businesses and organizations' diverse needs.
Architecture
Private cloud computing infrastructure generally involves a mix of hardware, network infrastructure, and virtualization software.
The hardware, often referred to as a cloud server or cloud array, consists of a server rack or a collection of server racks containing the storage and processors that constitute the cloud.
The virtualization software, such as Hyper-V, OpenStack, or VMWare, establishes and oversees virtual machines with which users interact.
The network infrastructure connects the private cloud to users and may facilitate connectivity with other on-premises data centers or clouds.
Applications
Private cloud infrastructures are usually utilized by medium to large businesses and organizations that need robust control over their data, have extensive computing needs, or have specific regulatory or compliance obligations. This includes healthcare organizations, government agencies, financial institutions, and any business that needs to process and store large data volumes.
See also
Cloud computing
Edge Computing
References
Cloud computing
Information technology | Private cloud computing infrastructure | [
"Technology"
] | 434 | [
"Information and communications technology",
"Information technology"
] |
74,267,976 | https://en.wikipedia.org/wiki/Ilaria%20Testa | Ilaria Testa is an Italian-born scientist who is a Professor at the Department of Applied Physics at the School of Engineering Science at the KTH Royal Institute of Technology. She has made major contributions to advanced microscopy, particularly superresolution microscopy (RESOLFT, STED).
Education
Testa studied physics at University of Genoa in Italy and graduated with a M.Sc. in 2005. In 2009, she earned her Ph.D. in Biotechnology. During her Ph.D., she worked on quantitative methods in single-molecule biophysics and studied transitional states in fluorescent proteins. After completing her thesis, supervised by Alberto Diaspro, she joined Stefan Hell's research group at the Max Planck Institute for Multidisciplinary Sciences in Göttingen, Germany as a postdoctoral researcher where she had already spent part of her doctoral studies.
Career and research
At the Max Planck Institute for Multidisciplinary Sciences in Göttingen, Testa played a central role in establishing the superresolution technique RESOLFT, showing that superresolution microscopy can be realized with lower levels of light in living cells and tissues making it more attractive for its usage in the life sciences.
From 2015 to 2024, Testa was appointed as a Fellow at the SciLifeLab in Stockholm and served as both an assistant professor and an associate professor at the KTH Royal Institute of Technology. At the SciLifeLab, she set up the Laboratory for Advanced Optical BioImaging.
In November 2024, she was appointed professor at the KTH Royal Institute of Technology.
Testa and her team continue to develop further and use superresolution techniques such as STED and RESOLFT microscopy to understand the fundamental biological processes for health and diseases.
Testa is a well-known microscopist who is an established member of the advanced microscopy community and is frequently invited on panels and as a keynote speaker at key conferences in the field.
Awards and honors
2015, ERC Starting Grant "MoNaLISA"
2017, ESP Young Investigator Award
2020, ERC Consolidator Grant "InSpIRe"
2025, RMS Award for Light Microscopy
References
External links
Can Microscopes Make Decisions? | Ilaria Testa | TEDxKTH
The Microscopists interviews Ilaria Testa
Living people
Women in optics
Year of birth missing (living people)
Microscopists
Optical physicists
European Research Council grantees
University of Genoa alumni
21st-century women physicists | Ilaria Testa | [
"Chemistry"
] | 497 | [
"Microscopists",
"Microscopy"
] |
74,269,270 | https://en.wikipedia.org/wiki/Machine-learned%20interatomic%20potential | Machine-learned interatomic potentials (MLIPs), or simply machine learning potentials (MLPs), are interatomic potentials constructed by machine learning programs. Beginning in the 1990s, researchers have employed such programs to construct interatomic potentials by mapping atomic structures to their potential energies. These potentials are referred to as MLIPs or MLPs.
Such machine learning potentials promised to fill the gap between density functional theory, a highly accurate but computationally intensive modelling method, and empirically derived or intuitively-approximated potentials, which were far lighter computationally but substantially less accurate. Improvements in artificial intelligence technology heightened the accuracy of MLPs while lowering their computational cost, increasing the role of machine learning in fitting potentials.
Machine learning potentials began by using neural networks to tackle low-dimensional systems. While promising, these models could not systematically account for interatomic energy interactions; they could be applied to small molecules in a vacuum, or molecules interacting with frozen surfaces, but not much else – and even in these applications, the models often relied on force fields or potentials derived empirically or with simulations. These models thus remained confined to academia.
Modern neural networks construct highly accurate and computationally light potentials, as theoretical understanding of materials science was increasingly built into their architectures and preprocessing. Almost all are local, accounting for all interactions between an atom and its neighbor up to some cutoff radius. There exist some nonlocal models, but these have been experimental for almost a decade. For most systems, reasonable cutoff radii enable highly accurate results.
Almost all neural networks intake atomic coordinates and output potential energies. For some, these atomic coordinates are converted into atom-centered symmetry functions. From this data, a separate atomic neural network is trained for each element; each atomic network is evaluated whenever that element occurs in the given structure, and then the results are pooled together at the end. This process – in particular, the atom-centered symmetry functions which convey translational, rotational, and permutational invariances – has greatly improved machine learning potentials by significantly constraining the neural network search space. Other models use a similar process but emphasize bonds over atoms, using pair symmetry functions and training one network per atom pair.
Other models to learn their own descriptors rather than using predetermined symmetry-dictating functions. These models, called message-passing neural networks (MPNNs), are graph neural networks. Treating molecules as three-dimensional graphs (where atoms are nodes and bonds are edges), the model takes feature vectors describing the atoms as input, and iteratively updates these vectors as information about neighboring atoms is processed through message functions and convolutions. These feature vectors are then used to predict the final potentials. The flexibility of this method often results in stronger, more generalizable models. In 2017, the first-ever MPNN model (a deep tensor neural network) was used to calculate the properties of small organic molecules. Such technology was commercialized, leading to the development of Matlantis in 2022, which extracts properties through both the forward and backward passes.
Gaussian Approximation Potential (GAP)
One popular class of machine-learned interatomic potential is the Gaussian Approximation Potential (GAP), which combines compact descriptors of local atomic environments with Gaussian process regression to machine learn the potential energy surface of a given system. To date, the GAP framework has been used to successfully develop a number of MLIPs for various systems, including for elemental systems such as Carbon, Silicon, Phosphorus, and Tungsten, as well as for multicomponent systems such as Ge2Sb2Te5 and austenitic stainless steel, Fe7Cr2Ni.
References
Machine learning
Materials science
Density functional theory software | Machine-learned interatomic potential | [
"Physics",
"Chemistry",
"Materials_science",
"Engineering"
] | 783 | [
"Applied and interdisciplinary physics",
"Computational chemistry software",
"Machine learning",
"Materials science",
"Density functional theory software",
"nan",
"Artificial intelligence engineering"
] |
74,269,295 | https://en.wikipedia.org/wiki/Suenosue%20Kiln%20ruins | The is an archaeological site containing a Nara period kiln located in the Sue neighborhood of the city of Yamaguchi, Yamaguchi Prefecture in the San'yō region of Japan. The site was designated a National Historic Site of Japan in 1948.
Overview
The Suenosue kiln site is located on a southern slope of a hill and is believed to date from the 6th century. As can be inferred from the name of the place where it is located, the entire area has long been known as the site of a Sue ware factory from ancient times. The ruins of a pottery kiln were discovered in 1936, and many pieces of Sue ware were excavated from inside. The kiln was about nine meters long (of which about 2.8 meters survive), and about 1.2 meters wide at the back wall, and about one meter in height. The lower firing port is buried, but the ceiling near the back wall remains, and there is also a smoke vent, so the structure of the semi-underground climbing kiln is preserved. It is thought that the reason why many Sue wares were produced in this area was because there was good quality clay in the vicinity and because the Suō Provincial Capital was nearby. The site is about 15 minutes by car from the Chugoku Expressway Ogori IC.
See also
List of Historic Sites of Japan (Yamaguchi)
References
External links
Yamaguchi Prefecture Tourism, Sports and Culture Department Culture Promotion Division
Yamaguchi City home page
History of Yamaguchi Prefecture
Yamaguchi (city)
Suō Province
Historic Sites of Japan
Japanese pottery kiln sites | Suenosue Kiln ruins | [
"Chemistry",
"Engineering"
] | 327 | [
"Kilns",
"Japanese pottery kiln sites"
] |
74,270,344 | https://en.wikipedia.org/wiki/Hysterangium%20bonobo | Hysterangium bonobo is a species of fungus found in the Democratic Republic of the Congo. Also known as simbokilo, the truffle-like species is named for bonobos, one of the species known to eat the fruiting bodies.
Naming and taxonomy
In the Bantu language Bongando, Hysterangium bonobo is known as simbokilo, which is linked to a longer phrase that translates roughly as "don't let your brother-in-law leave because traps baited with this will bring in plenty of food".
Hysterangium bonobo was first described in the journal Mycologia in 2020 based on specimen gathered within the Kokolopori Bonobo Reserve in the Democratic Republic of the Congo. It is named for bonobos (Pan paniscus), a primate species known to unearth and consume the fruiting bodies. Primatologist Alexander Georgiev observed wild bonobos consuming the fungi in the reserve and collected samples for analysis.
Description
The basidiocarp of Hysterangium bonobo is hypogeous to partially emergent, as wide as 50 mm. It is dull to light brown and irregularly globose. Its outer layer is lined with crystal-encrusted microscopic filaments which may play a role in aroma diffusion or defense. Analysis of Hysterangium bonobo indicated that the fungi had high concentrations of sodium.
Use
Hysterangium bonobo is a food source for bonobos. The truffles are probably located through their scent, detected either in the air or on the hands of bonobos after digging through soil. A 2021 article in the American Journal of Primatology addressed the nutritional content of Hysterangium bonobo and bonobo feeding patterns. The research indicated that while the fungi were not a staple food source, they could be a supplemental source of sodium in the bonobo diet.
During forest hunting expeditions, some Congolese trappers use Hysterangium bonobo as bait for various small mammals.
References
Fungi of Africa
Fungi described in 2020
Hysterangiales
Fungus species | Hysterangium bonobo | [
"Biology"
] | 440 | [
"Fungi",
"Fungus species"
] |
74,274,244 | https://en.wikipedia.org/wiki/Audio%20inpainting | Audio inpainting (also known as audio interpolation) is an audio restoration task which deals with the reconstruction of missing or corrupted portions of a digital audio signal. Inpainting techniques are employed when parts of the audio have been lost due to various factors such as transmission errors, data corruption or errors during recording.
The goal of audio inpainting is to fill in the gaps (i.e., the missing portions) in the audio signal seamlessly, making the reconstructed portions indistinguishable from the original content and avoiding the introduction of audible distortions or alterations.
Many techniques have been proposed to solve the audio inpainting problem and this is usually achieved by analyzing the temporal and spectral information surrounding each missing portion of the considered audio signal.
Classic methods employ statistical models or digital signal processing algorithms to predict and synthesize the missing or damaged sections. Recent solutions, instead, take advantage of deep learning models, thanks to the growing trend of exploiting data-driven methods in the context of audio restoration.
Depending on the extent of the lost information, the inpainting task can be divided in three categories.
Short inpainting refers to the reconstruction of few milliseconds (approximately less than 10) of missing signal, that occurs in the case of short distortions such as clicks or clipping.
In this case, the goal of the reconstruction is to recover the lost information exactly.
In long inpainting instead, with gaps in the order of hundreds of milliseconds or even seconds, this goal becomes unrealistic, since restoration techniques cannot rely on local information.
Therefore, besides providing a coherent reconstruction, the algorithms need to generate new information that has to be semantically compatible with the surrounding context (i.e., the audio signal surrounding the gaps).
The case of medium duration gaps lays between short and long inpainting.
It refers to the reconstruction of tens of millisecond of missing data, a scale where the non-stationary characteristic of audio already becomes important.
Definition
Consider a digital audio signal . A corrupted version of , which is the audio signal presenting missing gaps to be reconstructed, can be defined as , where is a binary mask encoding the reliable or missing samples of , and represents the element-wise product.
Audio inpainting aims at finding (i.e., the reconstruction), which is an estimation of . This is an ill-posed inverse problem, which is characterized by a non-unique set of solutions. For this reason, similarly to the formulation used for the inpainting problem in other domains, the reconstructed audio signal can be found through an optimization problem that is formally expressed as
.
In particular, is the optimal reconstructed audio signal and is a distance measure term that computes the reconstruction accuracy between the corrupted audio signal and the estimated one. For example, this term can be expressed with a mean squared error or similar metrics.
Since is computed only on the reliable frames, there are many solutions that can minimize . It is thus necessary to add a constraint to the minimization, in order to restrict the results only to the valid solutions. This is expressed through the regularization term that is computed on the reconstructed audio signal . This term encodes some kind of a-priori information on the audio data. For example, can express assumptions on the stationarity of the signal, on the sparsity of its representation or can be learned from data.
Techniques
There exist various techniques to perform audio inpainting. These can vary significantly, influenced by factors such as the specific application requirements, the length of the gaps and the available data. In the literature, these techniques are broadly divided in model-based techniques (sometimes also referred as signal processing techniques) and data-driven techniques.
Model-based techniques
Model-based techniques involve the exploitation of mathematical models or assumptions about the underlying structure of the audio signal. These models can be based on prior knowledge of the audio content or statistical properties observed in the data. By leveraging these models, missing or corrupted portions of the audio signal can be inferred or estimated.
An example of a model-based techniques are autoregressive models. These methods interpolate or extrapolate the missing samples based on the neighboring values, by using mathematical functions to approximate the missing data. In particular, in autoregressive models the missing samples are completed through linear prediction. The autoregressive coefficients necessary for this prediction are learned from the surrounding audio data, specifically from the data adjacent to each gap.
Some more recent techniques approach audio inpainting by representing audio signals as sparse linear combinations of a limited number of basis functions (as for example in the Short Time Fourier Transform). In this context, the aim is to find the sparse representation of the missing section of the signal that most accurately matches the surrounding, unaffected signal.
The aforementioned methods exhibit optimal performance when applied to filling in relatively short gaps, lasting only a few tens of milliseconds, and thus they can be included in the context of short inpainting. However, these signal-processing techniques tend to struggle when dealing with longer gaps. The reason behind this limitation lies in the violation of the stationarity condition, as the signal often undergoes significant changes after the gap, making it substantially different from the signal preceding the gap.
As a way to overcome these limitations, some approaches add strong assumptions also about the fundamental structure of the gap itself, exploiting sinusoidal modeling or similarity graphs to perform inpainting of longer missing portions of audio signals.
Data-driven techniques
Data-driven techniques rely on the analysis and exploitation of the available audio data. These techniques often employ deep learning algorithms that learn patterns and relationships directly from the provided data. They involve training models on large datasets of audio examples, allowing them to capture the statistical regularities present in the audio signals. Once trained, these models can be used to generate missing portions of the audio signal based on the learned representations, without being restricted by stationarity assumptions.
Data-driven techniques also offer the advantage of adaptability and flexibility, as they can learn from diverse audio datasets and potentially handle complex inpainting scenarios.
As of today, such techniques constitute the state-of-the-art of audio inpainting, being able to reconstruct gaps of hundreds of milliseconds or even seconds. These performances are made possible by the use of generative models that have the capability to generate novel content to fill in the missing portions. For example, generative adversarial networks, which are the state-of-the-art of generative models in many areas, rely on two competing neural networks trained simultaneously in a two-player minmax game: the generator produces new data from samples of a random variable, the discriminator attempts to distinguish between generated and real data.
During the training, the generator's objective is to fool the discriminator, while the discriminator attempts to learn to better classify real and fake data.
In GAN-based inpaniting methods the generator acts as a context encoder and produces a plausible completion for the gap only given the available information surrounding it. The discriminator is used to train the generator and tests the consistency of the produced inpainted audio.
Recently, also diffusion models have established themselves as the state-of-the-art of generative models in many fields, often beating even GAN-based solutions. For this reason they have also been used to solve the audio inpainting problem, obtaining valid results. These models generate new data instances by inverting the diffusion process, where data samples are progressively transformed into Gaussian noise.
One drawback of generative models is that they typically need a huge amount of training data. This is necessary to make the network generalize well and make it able to produce coherent audio information, that also presents some kind of structural complexity.
Nonetheless, some works demonstrated that, capturing the essence of an audio signal is also possible using only a few tens of seconds from a single training sample. This is done by overfitting a generative neural network to a single training audio signal. In this way, researchers were able to perform audio inpainting without exploiting large datasets.
Applications
Audio inpainting finds applications in a wide range of fields, including audio restoration and audio forensics among the others. In these fields, audio inpainting can be used to eliminate noise, glitches, or undesired distortions from an audio recording, thus enhancing its quality and intelligibility. It can also be employed to recover deteriorated old recordings that have been affected by local modifications or have missing audio samples due to scratches on CDs.
Audio inpainting is also closely related to packet loss concealment (PLC). In the PLC problem, it is necessary to compensate the loss of audio packets in communication networks. While both problems aim at filling missing gaps in an audio signal, PLC has more computation time restrictions and only the packets preceding a gap are considered to be reliable (the process is said to be causal).
See also
Audio forensics
Audio restoration
Image inpainting
Packet loss concealment
References
Machine learning
Deep learning
Digital signal processing | Audio inpainting | [
"Engineering"
] | 1,894 | [
"Artificial intelligence engineering",
"Machine learning"
] |
74,274,721 | https://en.wikipedia.org/wiki/UWB%20ranging | Ultra-wideband impulse radio ranging (or UWB-IR ranging) is a wireless positioning technology based on IEEE 802.15.4z standard, which is a wireless communication protocol introduced by IEEE, for systems operating in unlicensed spectrum, equipped with extremely large bandwidth transceivers. UWB enables very accurate ranging (in the order of centimeters) without introducing significant interference with narrowband systems. To achieve these stringent requirements, UWB-IR systems exploit the available bandwidth (which exceeds 500 MHz for systems compliant to IEEE 802.15.4z protocol) that they support, which guarantees very accurate timing (and thus ranging) and robustness against multipath, especially in indoor environments. The available bandwidth also enables UWB systems to spread the signal power over a large spectrum (this technology is thus called spread spectrum), avoiding narrowband interference.
Protocol
UWB-IR relies on the low-power transmission of specific sequences of short-duration pulses. The transmit power is limited according to FCC regulations, in order to reduce interference and power consumption. The bands supported by the standard are the following ones:
The sub-gigahertz band, which contains only 1 channel and ranges from 249.6 MHz to 749.6 MHz.
The low band, which contains 4 channels and ranges from 3.1 GHz to 4.8 GHz.
The high band, which contains 11 channels and ranges from 6.0 GHz to 10.6 GHz.
The primary time division in UWB systems is structured in frames. Each frame is composed by the concatenation of 2 sequences:
The first one is called preamble (also known as SHR or synchronization header) and consists of a header, known a priori both at transmitter and receiver side. It is employed for synchronization purposes.
The second one is called physical layer protocol data unit (abbreviated to PPDU) and contains the data to communicate, which are known a priori only at transmitter side.
The further time subdivisions of the preamble and the PPDU are organized in different ways. For localization purposes, only the preamble is employed (and described in detail later on), since it is specifically designed to perform accurate synchronization at receiver side.
The SHR sequence is composed by the concatenation of 2 other subsequences:
The first one is called synchronization sequence (abbreviated to SYNC) and it is the longest one. Its purpose is to increase the effective SNR and simultaneously exhibit a highly peaked autocorrelation function, in order to enhance synchronization accuracy.
The second one is called start of frame delimiter sequence (abbreviated to SFD) and, as the name suggests, it is employed to efficiently recognize the time delimitations of the various frames.
Both the SYNC and the SFD sequences are furtherly time-divided into symbols.
The SYNC sequence consists of identical symbols.
The SFD sequence consists of different symbols, generated according to a specific code which enables to easily detect the time delimitations of the frame.
Each symbol consists of a sequence of bursts, generated through a ternary code (the elements of the sequence can be 0, +1, -1) of length 31 or 127. These codes are specifically designed to have highly peaked autocorrelation and very-low cross-correlation, in order to simplify synchronization through peak-finding and simultaneously avoiding false alarms (i.e. detection of a code which was not transmitted).
Each burst is furtherly divided in chips.
is called spreading factor and it is defined as the ratio between the PRF and the chip rate. can be equal to 16 or 64 for length-31 codes while it is set to 4 for length-127 codes; thus the number of chips per symbol . The purpose of the spreading factor, as the name suggests, is to spread the signal in time domain, in order to make the chips very sparse in time, allowing to reduce interference with other systems operating in the same band.
The chip rate is = 500 MHz or, alternatively, the chip time is = 2 ns.
Each chip is modulated by the same pulse waveform.
The pulse waveform is not specified by the protocol, thus it is left to user preference. However the spectrum of the pulses must be entirely contained in the allowed channels.
SHR waveform
The transmitted SHR waveform (baseband equivalent) can be modeled as follows
where the parameters are defined as shown here below
.
is the pulse shape.
is the spreading factor.
is the number of chips per symbol.
is the chip time.
The received SHR waveform can instead be described as
where the additional parameters are defined as follows
and are the complex channel gain and the propagation delay associated to the path.
is the noise waveform, which is usually described as AWGN.
In order to associate the propagation delay to a distance, there must exists a LoS path between transmitter and receiver or, alternatively, a detailed map of the environment has to be known in order to perform localization based on the reflected rays.
In presence of multipath, the large bandwidth is of paramount importance to distinguish all the replicas, which otherwise would significantly overlap at receiver side, especially in indoor environments.
Ranging
The propagation delay can be estimated through several algorithms, usually based on finding the peak of the cross-correlation between the received signal and the transmitted SHR waveform. Commonly used algorithms are maximum correlation and maximum likelihood.
There are two methods to estimate the mutual distance between the transceivers. The first one is based on the time of arrival (TOA) and it is called one-way ranging. It requires a priori synchronization between the anchors and it consists in estimating the delay and computing the range as
where refers to the LoS path estimated delay.
The second method is based on the round-trip time (RTT) and it is called two-way ranging. It consists in the following procedure:
The first anchor transmits a data frame
The second anchor receives the frame and waits for a fixed amount of time
After waiting for a time , the second anchor transmits the acknowledgment frame
The first anchor receives the acknowledgment frame and estimates the delay accumulated since the transmission of the initial data frame
In this second case the distance between the 2 anchors can be computed as
Also in this case refers to the LoS path estimated delay.
Pros and cons
Performing ranging through UWB presents several advantages:
The transmit power is very low (0.1 mW), allowing to save battery and limiting interference with other communication systems.
Due to low transmit power, high spreading factor and employment of effective ternary ranging codes, interference is very limited.
Limited interference enables many different systems (such as Wi-Fi, Bluetooth, cordless phones, etc...) to operate in the same band without impair (or introducing very low impairments) each other.
UWB operates in unlicensed spectrum, therefore no license is required, making these systems relatively cheap.
High sparsity in time domain and usage of ternary ranging codes, allow high frequency reuse, since the band is much larger than the typical required bit rate.
Since the bandwidth is large, high data rate transmissions are supported, in case low-latency data communication is necessary to perform the localization (e.g. communicating anchor reference position, velocity and timing).
Precise temporal (and thus range) resolution can be achieved through large bandwidth, which also allows to accurately discriminate the multipath replicas at receiver side.
The method based on RTT does not require a priori synchronization.
However, there are also some disadvantages related to UWB systems:
Due to low transmit power limits, UWB systems can operate only at short range otherwise the signal is undetectable at receiver side.
Due to large bandwidth, the noise power level is typically high, degrading the SNR and thus the ranging accuracy.
Large bandwidth requires high sampling frequencies, which can make the transceivers pretty expensive.
See also
IEEE 802.15.4
List of UWB channels
Spread spectrum
Indoor positioning system
Time of arrival
Round-trip delay
References
External links
A Survey on Wireless Position Estimation
High accuracy UWB localization in dense indoor environments
An Overview of the IEEE 802.15.4z Standard its Comparison and to the Existing UWB Standards
Data transmission
Radio communications
Radio technology | UWB ranging | [
"Technology",
"Engineering"
] | 1,737 | [
"Information and communications technology",
"Radio communications",
"Telecommunications engineering",
"Radio technology"
] |
74,274,754 | https://en.wikipedia.org/wiki/AI-assisted%20reverse%20engineering | AI-assisted reverse engineering (AIARE) is a branch of computer science that leverages artificial intelligence (AI), notably machine learning (ML) strategies, to augment and automate the process of reverse engineering. The latter involves breaking down a product, system, or process to comprehend its structure, design, and functionality. AIARE was primarily introduced in the early years of the 21st century, witnessing substantial advancements from the mid-2010s onwards.
Overview
Conventionally, reverse engineering is conducted by specialists who dismantle a system to grasp its working principles, often for the purposes of reproduction, modification, enhancement of compatibility, or forensic examination. This method, while efficient, can be laborious and time-intensive, particularly when dealing with intricate software or hardware systems.
AIARE integrates machine learning algorithms to either partially automate or augment this process. It is capable of detecting patterns, relationships, structures, and potential vulnerabilities within the analyzed system, frequently surpassing human experts in speed and accuracy. This has rendered AIARE a critical tool in numerous fields, including cybersecurity, software development, and hardware design and analysis.
Techniques
AIARE encompasses several AI methodologies:
Supervised learning
Supervised learning employs tagged data to train models to recognize system components, their operations, and their interconnections. This method is particularly helpful in software analysis to discover vulnerabilities or enhance compatibility.
Unsupervised learning
Unsupervised learning is utilized to detect concealed patterns and structures in untagged data. It proves beneficial in comprehending complex systems where there's no evident labeling or mapping of components.
Reinforcement learning
Reinforcement learning is employed to build models that progressively refine their system understanding through a process of trial and error. This method is often implemented when deciphering a system's functionality under various circumstances or configurations.
Deep learning
Deep learning is employed for analysis of high-dimensional data. For instance, deep learning techniques can aid in examining the layout and connections of integrated circuits (ICs), substantially reducing the manual effort required for reverse engineering.
References
Applications of artificial intelligence
Reverse engineering | AI-assisted reverse engineering | [
"Engineering"
] | 428 | [
"Reverse engineering"
] |
74,275,256 | https://en.wikipedia.org/wiki/Lotiglipron | Lotiglipron is a non-peptide glucagon-like peptide-1 receptor agonist developed as a weight loss drug by Pfizer. It was withdrawn from development after early stage clinical trials showed elevated liver enzymes which could indicate potential for liver toxicity.
See also
Danuglipron
Orforglipron
References
Experimental drugs
GLP-1 receptor agonists
Chloropyridines
Benzodioxoles
Piperidines
Benzimidazoles
Oxetanes
Carboxylic acids | Lotiglipron | [
"Chemistry"
] | 105 | [
"Carboxylic acids",
"Functional groups"
] |
74,277,228 | https://en.wikipedia.org/wiki/Iridium%28III%29%20bromide | Iridium(III) bromide is a bromide of iridium(III), with the chemical formula of IrBr3.
Preparation
Iridium(III) bromide can be formed by reacting iridium(II) bromide and bromine. Its tetrahydrate can be formed by reacting iridium dioxide dihydrate with hydrobromic acid. It can also be formed by the direct reaction of iridium and bromine at 8 atm and 570 °C.
Properties
Iridium(III) bromide is a dark reddish-brown solid that is insoluble soluble in water, acids, and alkalis and decomposes to iridium(II) bromide on heating. It crystallizes in a highly disordered layered structure of aluminum(III) chloride or chromium(III) chloride type, where the monoclinic unit cell contains four formula units. As with rhenium(III) chloride, rhenium(III) bromide, α-iridium(III) chloride and α-ruthenium(III) chloride, the disorder is due to the different stacking of the metal layers. The light olive green tetrahydrate is slightly soluble in water but insoluble in ethanol and ether. When heated to 100 °C, it turns dark brown with release of water and decomposes to iridium and bromine at higher temperatures. It reacts with germanium dibromide in hydrobromic acid solution to form a compound containing Ir-Ge bond, and adding Cs+ to it can separate Cs3[Ir(GeBr3)nBr6−n] (n=1, 2, 3).
References
Iridium compounds
Bromides | Iridium(III) bromide | [
"Chemistry"
] | 353 | [
"Bromides",
"Salts"
] |
74,277,546 | https://en.wikipedia.org/wiki/Computed%20torque%20control | Computed torque control is a control scheme used in motion control in robotics. It combines feedback linearization via a PID controller of the error with a dynamical model of the controlled robot.
Let the dynamics of the controlled robot be described by
where is the state vector of joint variables that describe the system, is the inertia matrix, is the vector Coriolis and centrifugal torques, are the torques caused by gravity and is the vector of joint torque inputs.
Assume that we have an approximate model of the system made up of . This model does not need to be perfect, but it should justify the approximations and .
Given a desired trajectory the error relative to the current state is then .
We can then set the input of the system to be
With this input the dynamics of the entire systems becomes
and the normal methods for PID controller tuning can be applied. In this way the complicated nonlinear control problem has been reduced to a relatively simple linear control problem.
References
Motion control
Robotics engineering | Computed torque control | [
"Physics",
"Technology",
"Engineering"
] | 203 | [
"Physical phenomena",
"Computer engineering",
"Robotics engineering",
"Automation",
"Motion (physics)",
"Motion control"
] |
74,278,058 | https://en.wikipedia.org/wiki/Germanium%20dibromide | Germanium dibromide is a bromide of germanium with the chemical formula GeBr2.
Preparation
Germanium dibromide can be obtained by reducing germanium tetrabromide with germanium or zinc.
Ge + GeBr4 -> 2GeBr2
Properties
Germanium dibromide is a yellow-white solid that is soluble in ethanol and acetone. It disproportionates into germanium tetrabromide and germanium. It hydrolyzes to germanium dihydroxide. Germanium dibromide is monoclinic, space group P21/c (No. 14), lattice parameters a = 11.68 Å, b = 9.12 Å, c = 7.02 Å, and β = 101.9°. It can react with cyclopentadienylsodium or cyclopentadienylthallium in ether solvent to form germanocene.
References
Germanium compounds
Bromides | Germanium dibromide | [
"Chemistry"
] | 197 | [
"Bromides",
"Salts"
] |
74,279,701 | https://en.wikipedia.org/wiki/NGC%207720 | NGC 7720 is an elliptical galaxy located in the constellation Pegasus. It is located at a distance of about 380 million light years from Earth, which, given its apparent dimensions, means that NGC 7720 is about 180,000 light years across. NGC 7720 is the main galaxy of Abell 2634 galaxy cluster and is a radio galaxy. It was discovered by William Herschel on September 10, 1784.
Characteristics
NGC 7720 is made of a galaxy pair that is separated by 12 arcseconds. The south galaxy is the one associated with the radio source. In the centre of the galaxy lies a dust disk is visible nearly face on. The dust mass of NGC 7720 is estimated to be between to . There is also ionized Hα+[N II] gas emission from the disk. NGC 7720A features too a dusty disk.
Radio jet
NGC 7720 is a Fanaroff-Riley type I radio galaxy, and is also categorised as a wide angle tail (WAT) radio galaxy. It has two asymmetrical radio jets that emerge from the bright radio core. The core didn't exhibit variability when observed by the Very Large Array (VLA). In parsec scales, the jet is one sided features relativistic motion, about 0.6 times the speed of light, and has a northwest direction.
The northwest jet is the main one and forms a distorted plume about 5 arcminutes long, with a hotspot about 30 arcseconds from the core. The southeastern jet has a bright spot about 30 arcseconds from the core and then fans to a distorted plume that extends for 5 arcminutes. In large scales the jets appear bend, maybe due to ram pressure as the galaxy moves through the intracluster medium.
X-ray emission has been detected by the radio jet, indicating the contribution of synchroton mechanism to the creation of the jet. The radio plumes are regions with decreased X-ray emission.
The most accepted theory for the energy source of active galactic nuclei is the presence of an accretion disk around a supermassive black hole. The mass of the black hole in the centre of NGC 7720 is estimated to be (1.9 billion) based on stellar velocity dispersion or (1.81 billion) based on mass of the bulge.
Nearby galaxies
NGC 7720 is the dominant galaxy in Abell 2634 galaxy cluster. It is classified as a poor galaxy cluster and has a total X-ray luminosity of erg/s, which is considered low in relation to other similar clusters. X-ray bolometric luminosity has a central peak which corresponds to NGC 7720, while excess emission is to the southwest, perpendicularly to the radio jets.
About 118 galaxies lie within half degree from the centre of the cluster and are considered to be members of the cluster. Abell 2634 forms a pair with galaxy cluster Abell 2666, which is located 3 degrees to the east, but has lower redshift. Both clusters lie behind the Perseus–Pisces Supercluster. Abell 2622 lies behind Abell 2634, at about double the redshift.
See also
NGC 383 - a similar radio galaxy
References
External links
NGC 7720 on SIMBAD
Elliptical galaxies
Peculiar galaxies
Radio galaxies
Pegasus (constellation)
7720
12716
465
4C objects
71985
Discoveries by William Herschel
Astronomical objects discovered in 1784 | NGC 7720 | [
"Astronomy"
] | 713 | [
"Pegasus (constellation)",
"Constellations"
] |
74,280,706 | https://en.wikipedia.org/wiki/Epidemiology%20of%20gonorrhoea | Gonorrhoea is a sexually transmitted infection (STI) caused by the bacterium Neisseria gonorrhoeae.
The World Health Organization (WHO) estimated that, in 2016, the global incidence rate was 20 per 1000 women and 26 per 1000 men, totaling 86.9 million new gonococcal infections among people between 15 and 49 years old.
Canada
As of 2018, gonorrhoea was the second most commonly reported STI in Canada. Its incidence rate has been rising since 1997.
Incidence rate among men was consistently higher than that among women (70.2 per 100,000 versus 40.6 per 100,000 in 2015). It was also increasing faster among men than women (85.2% versus 39.5% in 2010–2015). People between 15 and 29 years old had the highest rate. Geographically, the highest gonorrhoea rates in 2015 were found in the Northwest Territories, Nunavut and Yukon.
Nordic countries
In Nordic countries, gonorrhoea affects mainly young people below the age of 30. Infections are more common in men than in women. Nearly half of the reported cases of gonorrhoea are attributed to men who have sex with men (MSM).
Greenlandic women have the highest incidence rate. In contrast to the other Nordic countries, in Greenland, the numbers of cases among women and among men are almost equally high. Incidence rates are significantly lower in the other Nordic countries. However, cases are rising in Denmark, Iceland, Norway and Sweden. The Faroe Islands has relatively few cases.
United Kingdom
In England, there were 82,592 diagnoses of gonorrhoea in 2022, an increase of 50.3% compared to 2021 (54,961). The number of gonorrhoea diagnoses in 2022 was the largest annual number reported since records began.
Diagnoses were increasing in people of all ages in England, but the rise was highest among young people aged 15 to 24 years. This trend was also detected in Scotland.
United States
Sexually transmitted disease surveillance 2020 published by the Centers for Disease Control and Prevention (CDC) showed that, in 2020, a total of 677,769 cases of gonorrhea were reported to the CDC, a 45 percent increase from 2016,making it the second most common notifiable sexually transmitted infection in the United States for that year. Rates of reported gonorrhea have increased 111% since the historic low in 2009. During 2019–2020, the overall rate of reported gonorrhea increased 5.7%; rates increased among both males and females and in three regions of the United States (Midwest, Northeast, and South); rates of reported gonorrhea increased in 36 states and two US territories.
Since 2013, rates have been higher among men compared to women, likely reflecting cases identified in both men who have sex with men (MSM) and men who have sex with women only. Although there are limited data available on sexual behaviors of persons reported with gonorrhea at the national level, enhanced data from jurisdictions participating in a sentinel surveillance system, the STD Surveillance Network (SSuN), suggest that about a third of gonorrhea cases occurred among MSM in 2020. During 2019–2020, rates increased among both men and women, but increases were greater among women (15%) compared to men (6.6%) which may reflect differences in diagnosing and reporting of cases among MSM in 2020. As extragenital infections are often asymptomatic and are likely identified by screening, diagnoses among MSM may have been reduced in 2020 due to the effect of the COVID-19 pandemic on screening coverage.
Gonorrhoea can quickly develop resistance to antibiotics used to treat infection, and in 2020, about half of all infections were estimated to be resistant to at least one antibiotic. Since 2010, almost all circulating strains in the United States, based on gonococcal isolates collected through sentinel surveillance in the Gonococcal Isolate Surveillance Project (GISP), remain susceptible to ceftriaxone, the primary treatment for gonorrhea; only 0.1% of isolates displayed elevated ceftriaxone minimum inhibitory concentrations (MICs) in 2020. In 2020, 5.8% of isolates had elevated azithromycin MICs; the proportion was higher among MSM compared to men who have sex with women only (9.2% vs 4.3%).
References
Gonorrhea
Epidemiology | Epidemiology of gonorrhoea | [
"Environmental_science"
] | 951 | [
"Epidemiology",
"Environmental social science"
] |
74,283,493 | https://en.wikipedia.org/wiki/Combinatorial%20Theory%20%28journal%29 | Combinatorial Theory is a peer-reviewed diamond open access mathematical journal specializing in the field of combinatorics. It was established in 2021, when the vast majority of the editorial board of the Elsevier-published Journal of Combinatorial Theory, Series A left to create a new journal.
Operations
The journal operates on a diamond open access model, in which publication costs are underwritten by voluntary contributions from universities, foundations, and other organizations. Authors do not pay submission fees or article processing charges, and the journal belongs to the Free Journal Network. All content is published under a Creative Commons license. The journal follows a doubly-anonymous review process, in which author names are not disclosed to reviewers.
Abstracting and indexing
The journal is abstracted and indexed in the Directory of Open Access Journals, the Free Journal Network, Mathematical Reviews, Zentralblatt Math, and Scopus.
References
External links
Academic journals established in 2021
Combinatorics journals
Triannual journals
Open access journals
Creative Commons-licensed journals | Combinatorial Theory (journal) | [
"Mathematics"
] | 206 | [
"Combinatorics journals",
"Combinatorics"
] |
74,284,664 | https://en.wikipedia.org/wiki/9855 | 9855 (nine thousand eight hundred fifty-five) is an odd, composite, four-digit number. The number 9855 is the magic constant of an n × n normal magic square as well as n-Queens Problem for n = 27. It can be expressed as the product of its prime factors:
9855 is also the Magic constant of a Magic square of order 27. In a magic square, the magic constant is the sum of numbers in each row, column, and diagonal, which is the same. For magic squares of order n, the magic constant is given by the formula .
The magic constant 9855 for the magic square of order 27 can be calculated as follows:
This square contains the numbers 1 to 729, with 365 in the center. The square consists of 9 nine power magic squares. It has been noted that the number of days in 27 years (365 days per year) is 9855, the constant of the larger square. This was first discovered and solved by ancient Greeks: Aristotle understood this magic square, but it is noted from numeris Platonics nihil obscuris that Cicero was unable to solve it. The 27 years as alluded to by the square was mentioned in reference to Greek generation time.
References
Integers | 9855 | [
"Mathematics"
] | 256 | [
"Elementary mathematics",
"Integers",
"Mathematical objects",
"Numbers"
] |
74,285,579 | https://en.wikipedia.org/wiki/Open-circuit%20saturation%20curve | The open-circuit saturation curve (also open-circuit characteristic, OCC) of a synchronous generator is a plot of the output open circuit voltage as a function of the excitation current or field. The curve is typically plotted alongside the synchronous impedance curve.
At the low field, the permeable iron in the magnetic circuit of the generator is not saturated, therefore the reluctance almost entirely depends on the fixed contribution of the air gap, so the part of the curve that starts at the point of origin is a linear "air-gap line" (output voltage is proportional to the excitation current). As the iron saturates with higher excitation and thus higher magnetic flux, the reluctance increases, and the OCC deflects down from the air-gap line.
The curve is obtained by rotating the generator at the rated RPM with the output terminals disconnected and the output voltage typically going to at least 120% of the rated for the device. The hydraulic units sometimes have to be tested at lower RPM with the resulting voltage scaled up to accommodate the differences in frequency. Since the test goes above the rated voltage, the step-up transformer is typically also disconnected to avoid damaging it.
The open circuit saturation curve could be used together with the zero power factor curve in Potier Triangle Method.
References
Sources
Electrical generators | Open-circuit saturation curve | [
"Physics",
"Technology"
] | 278 | [
"Physical systems",
"Electrical generators",
"Machines"
] |
74,285,940 | https://en.wikipedia.org/wiki/Synchronous%20impedance%20curve | The synchronous impedance curve (also short-circuit characteristic, SCC) of a synchronous generator is a plot of the output short circuit current as a function of the excitation current or field. The curve is typically plotted alongside the open-circuit saturation curve.
The SCC is almost linear, since under the short-circuit conditions the magnetic flux in the generator is below the iron saturation levels and thus the reluctance is almost entirely defined by the fixed one of the air gap. The name "synchronous impedance curve" is due to the fact that in the short-circuit condition all the generated voltage dissipates across the generator internal synchronous impedance .
The curve is obtained by rotating the generator at the rated RPM with the output terminals shorted and the output current going to 100% of the rated for the device (higher values are typically not tested to avoid overheating).
References
Sources
Electrical generators | Synchronous impedance curve | [
"Physics",
"Technology"
] | 198 | [
"Physical systems",
"Electrical generators",
"Machines"
] |
74,286,749 | https://en.wikipedia.org/wiki/Anna%20Becker | Anna Becker is an Israeli researcher known in the field of artificial intelligence and computer science within the financial field.
Early life and education
Becker was born in Russia and immigrated to Israel at 16 after graduating from a school in Moscow. At 17, she began her studies at Technion – Israel Institute of Technology. During her master's degree in computer science, she taught first-year students of the same course, and at 27, Becker completed her PhD in Computer Science and Artificial Intelligence.
Career
While pursuing her PhD, Becker resolved an NP-complete approximation algorithm that had been unresolved for over twenty years. This made her a recognized scholar in the field. After completing her PhD, she developed an approximation technique by a factor of two. This technique is widely used today in operating systems, database systems, and VLSI chip designs.
She then founded and sold Strategy Runner, a fintech software. After this, she founded EndoTech, an algorithmic trading platform based on artificial intelligence and machine learning. As of 2023, Becker is working on Fianchetto Fund, an AI-based investing analysis platform.
Becker has also co-authored a book on Bayesian networks, which has been published widely in the field of computer science and artificial intelligence.
References
Computer scientists
Artificial intelligence people
1973 births
Living people | Anna Becker | [
"Technology"
] | 265 | [
"Computer science",
"Computer scientists"
] |
74,287,597 | https://en.wikipedia.org/wiki/Spectroswiss | Spectroswiss is a Swiss technology company developing and producing hardware components and software for Fourier transform mass spectrometry. The company was formed in 2014 as a spin-out from the Biomolecular Mass Spectrometry Laboratory at Ecole Polytechnique Fédérale de Lausanne in Switzerland. The company's headquarters are located in Lausanne, Switzerland, with subsidiary in Cambridge, Massachusetts.
References
Mass spectrometry
Technology companies of Switzerland | Spectroswiss | [
"Physics",
"Chemistry"
] | 92 | [
"Spectrum (physical sciences)",
"Instrumental analysis",
"Mass",
"Mass spectrometry",
"Matter"
] |
74,288,076 | https://en.wikipedia.org/wiki/Coalescent%20angiogenesis | Angiogenesis is the process of the formation of new blood vessels from pre-existing vascular structures, which is needed for oxygenation of - and providing nutrients to - expanding tissue. Angiogenesis takes place through different modes of action. Coalescent angiogenesis is a mode of angiogenesis where vessels coalesce or fuse to increase blood circulation. This process transforms an inefficient net structure into a more efficient treelike structure. It is the opposite of intussusceptive angiogenesis, which is where vessels split to form new vessels.
Background
While the most studied mode of angiogenesis is sprouting angiogenesis, several different modes of angiogenesis have been described. Among these are intussusceptive angiogenesis or splitting angiogenesis, vessel cooption, and vessel elongation. A novel form of angiogenesis is the process called ‘’’coalescent angiogenesis’’’, which is the opposite of intussusceptive angiogenesis. This mode of angiogenesis was reported from studies of long-term time-lapse microscopy in the vasculature of the chick chorioallantoic membrane (CAM), where this novel non-sprouting mode for vessel generation was observed.
Specifically, isotropic capillary meshes enclosing tissue islands evolve into preferred flow pathways consisting of larger blood vessels transporting more blood in a faster pace. These preferential flow pathways progressively enlarge by coalescence of capillaries and elimination of internal tissue pillars, in a fast time frame of hours. This way coalescent angiogenesis is the reverse of intussusceptive angiogenesis. Concomitantly, less perfused segments of the vasculature regress. An initially mesh-like capillary network is remodelled into a tree structure, while conserving vascular wall components and maintaining blood flow. Coalescent angiogenesis, thus, describes the remodelling of an initial hemodynamically inefficient mesh structure, into a hierarchical tree structure that provides efficient convective transport, allowing for the rapid expansion of the vasculature with maintained blood supply and function during development.
Vascular fusion was initially described to happen during the formation of the dorsal aorta. All research presented has been derived from embryo development studies. It is unknown whether coalescent angiogenesis has extended out of the domain of embryology. In any case, it has been overlooked in the field of cancer research and it is currently only assumed to play a role in the formation of tumor vasculature.
References
Angiogenesis | Coalescent angiogenesis | [
"Biology"
] | 544 | [
"Angiogenesis"
] |
74,289,074 | https://en.wikipedia.org/wiki/Dieter%20Haidt | Dieter Haidt (born 1940) is a German physicist, known for his contribution to the 1973 discovery of weak neutral currents. The discovery was made in the Gargamelle experiment, which used a heavy liquid bubble chamber detector in operation at CERN from 1970 to 1979.
Education and career
In 1958 Haidt graduated from the Kepler-Gymnasium in Tübingen. He then studied physics at the University of Tübingen, where he graduated with a Diplom in experimental physics in 1965. He then moved to RWTH Aachen University, where he was a member of the X2 collaboration. He was also a visiting scholar at University College London in 1966. In 1969 he received his doctorate at RWTH Aachen University summa cum laude and in 1970 he received the Borchers Medal. From 1970 he was a member of the Gargamelle collaboration at CERN (from RWTH Aachen University) and from 1971 to 1978 he was employed at CERN. In 1973, the Gargamelle collaboration discovered weak neutral currents. The collaboration searched for weak neutral currents in neutrino reactions without muon generation. The discovery's rapid recognition depended, to a considerable extent, on calculations by Haidt, who showed that the existence of weak neutral currents was a new type of effect (and not, e.g., interactions between neutrons). Other prominent physicists involved in the Gargamelle experiment include Antonino Pullia (1935–2020), Helmut Faissner (1928–2007), and André Lagarrigue (1924–1975).
Haidt was a spokesperson for the neutrino-propane experiment at the Gargamelle bubble chamber. He was involved in neutrino experiments at the BEBC detector. From 1979 to 2004 he was a senior scientist at DESY. From 1979 to 1986 he was a member of the JADE collaboration at DESY and from 1994 of the H1 collaboration. He was a member of the Physics Research Committee (PRC) at DESY and organized the DESY seminars. In 2007 he received emeritus status.
For the academic year 1987–1988 he was a visiting scientist at Japanese particle physics laboratory known as KEK.
In 2011 he shared the Enrico Fermi Prize with Antonino Pullia. In 2009, the Gargamelle collaboration received the European Physical Society's High-Energy and Particle Physics Prize.
From 1986 to 1997 he was an editor for the Zeitschrift für Physik C and from 1997 to 2006 he was the editor-in-chief of its successor, the European Physical Journal C.
References
1940 births
Living people
People associated with CERN
German experimental physicists
Particle physicists
University of Tübingen alumni
RWTH Aachen University alumni | Dieter Haidt | [
"Physics"
] | 553 | [
"Particle physicists",
"Particle physics"
] |
74,289,294 | https://en.wikipedia.org/wiki/Idyll%20XXII | Idyll XXII, also called Διόσκουροι ('The Dioscuri'), is a poem by the 3rd-century BC Greek poet Theocritus. It is a hymn, in the Homeric manner, to Castor and Polydeuces.
Summary
This hymn to Castor and Polydeuces consists, first, of a prelude common to both, and secondly, of two main parts concerned one with Polydeuces and the other with Castor. The first of these, in a combination of the Epic style with the dialogue, tells how Polydeuces fought fisticuffs with Amycus on his way to Colchis, and the second how, when the brothers carried off the daughters of Leucippus, Castor fought Lynceus with spear and sword.
Analysis
Andrew Lang compares the "life and truth of the descriptions of nature, and of the boxing-match" in the Theocritean text with the "frigid manner" of Apollonius Rhodius on the same theme.
See also
Epyllion
References
Sources
Attribution:
Further reading
External links
Ancient Greek poems
3rd-century BC poems
Castor and Pollux | Idyll XXII | [
"Astronomy"
] | 253 | [
"Castor and Pollux",
"Astronomical myths"
] |
69,703,814 | https://en.wikipedia.org/wiki/Maggie%20%28astronomy%29 | Maggie is a vast cloud of hydrogen gas observed within our own Milky Way galaxy. It is a filament of hydrogen 3,900 light-years long and 130 light-years wide. It is a single coherent structure with all parts showing similar velocity with respect to the local standard of rest. It is one of the biggest structures within the Milky Way. "Maggie" is located about 55,000 light-years away (on the other side of the Milky Way). Maggie contains eight percent molecular hydrogen by mass fraction; the rest being atomic hydrogen. It is hoped the cloud will provide clues to one of the earliest stages of star formation.
It was first named by Colombian astronomer Juan D. Soler, an astrophysicist affiliated with the Istituto Nazionale di Astrofisica in Rome, Italy. He named it after the longest river in his native country, the Río Magdalena (Anglicized: Margaret, or "Maggie"). Astronomers discovered the cloud as part of The HI/OH/Recombination line survey of the Milky Way (THOR). It was first described in December 2021 in the journal Astronomy & Astrophysics.
References
Milky Way
Interstellar media
Molecular clouds
Radio astronomy
Star formation
Aquila (constellation) | Maggie (astronomy) | [
"Astronomy"
] | 254 | [
"Interstellar media",
"Outer space",
"Constellations",
"Radio astronomy",
"Aquila (constellation)",
"Astronomical sub-disciplines"
] |
69,704,037 | https://en.wikipedia.org/wiki/Lubabegron | Lubabegron (trade name Experior) is a veterinary drug used to reduce ammonia emissions from animals and their waste. Ammonia emissions are a concern in agricultural production because of detrimental effects on the environment, human health, and animal health.
Lubabegron was approved by the U.S. Food and Drug Administration in 2018 for use in feedlot cattle. It is the first drug approved for reducing ammonia emissions. It is also approved for use in Canada.
Lubabegron is a beta-adrenergic receptor agonist/antagonist. The antagonist activity of lubabegron at β1 and β2 receptors prevents the stimulation of the β-AR found in the heart (β1) and trachea/bronchi (β2) of humans and, in doing so, avoids the potential negative side effects associated with β1 and β2 receptor activation. The β1-AR and β2-AR antagonist behavior of lubabegron could decrease lipolysis in adipose tissue, whereas the β3-AR agonist activity could increase skeletal muscle hypertrophy, possibly due to the differences in the second messenger systems and enzyme expression in skeletal muscle compared with adipose tissues.
References
Veterinary drugs
Beta-adrenergic agonists
Nitriles
Pyridines
Thiophenes | Lubabegron | [
"Chemistry"
] | 275 | [
"Nitriles",
"Functional groups"
] |
69,706,366 | https://en.wikipedia.org/wiki/Bing%20%28measuring%20unit%29 | A Bing (秉) was a measuring unit used in ancient China for volume.
One bing was equal to 16 hu (斛), which themselves were equal to 10 dou (斗). A dou is near equivalent to 10 litres in modern units. Therefore, a bing would have been near equivalent to 1600 litres.
Usage
The bing unit was used in ancient times to measure volumes of grain.
It is mentioned in book six of the Analects when Ran Qiu requests Confucius, while he is presumably serving in the government of the State of Lu to give a dole of grain to Zihua's mother. Confucius offers to give only a fu (釜) and a yu (庾), together equaling about 88 litres of grain. Ran Qiu, who seems to feel this is too little, then provides her with 5 bing (8000 litres). Confucius then gives an indirect criticism saying that Zihua was a wealthy man and that it was not virtuous to give charity to the wealthy: "I have heard that a superior man helps the distressed, but does not add to the wealth of the rich."
References
Measurement
Ancient China | Bing (measuring unit) | [
"Physics",
"Mathematics"
] | 243 | [
"Quantity",
"Physical quantities",
"Measurement",
"Size"
] |
69,706,395 | https://en.wikipedia.org/wiki/Karmarkar%E2%80%93Karp%20bin%20packing%20algorithms | The Karmarkar–Karp (KK) bin packing algorithms are several related approximation algorithm for the bin packing problem. The bin packing problem is a problem of packing items of different sizes into bins of identical capacity, such that the total number of bins is as small as possible. Finding the optimal solution is computationally hard. Karmarkar and Karp devised an algorithm that runs in polynomial time and finds a solution with at most bins, where OPT is the number of bins in the optimal solution. They also devised several other algorithms with slightly different approximation guarantees and run-time bounds.
The KK algorithms were considered a breakthrough in the study of bin packing: the previously-known algorithms found multiplicative approximation, where the number of bins was at most for some constants , or at most . The KK algorithms were the first ones to attain an additive approximation.
Input
The input to a bin-packing problem is a set of items of different sizes, a1,...an. The following notation is used:
n - the number of items.
m - the number of different item sizes. For each i in 1,...,m:
si is the i-th size;
ni is the number of items of size si.
B - the bin size.
Given an instance I, we denote:
OPT(I) = the optimal solution of instance I.
FOPT(I) = (a1+...+an)/B = the theoretically-optimal number of bins, when all bins are completely filled with items or item fractions.
Obviously, FOPT(I) ≤ OPT(I).
High-level scheme
The KK algorithms essentially solve the configuration linear program:.Here, A is a matrix with m rows. Each column of A represents a feasible configuration - a multiset of item-sizes, such that the sum of all these sizes is at most B. The set of configurations is C. x is a vector of size C. Each element xc of x represents the number of times configuration c is used.
Example: suppose the item sizes are 3,3,3,3,3,4,4,4,4,4, and B=12. Then there are C=10 possible configurations: 3333; 333; 33, 334; 3, 34, 344; 4, 44, 444. The matrix A has two rows: [4,3,2,2,1,1,1,0,0,0] for s=3 and [0,0,0,1,0,1,2,1,2,3] for s=4. The vector n is [5,5] since there are 5 items of each size. A possible optimal solution is x=[1,0,0,0,0,0,1,0,0,1], corresponding to using three bins with configurations 3333, 344, 444.
There are two main difficulties in solving this problem. First, it is an integer linear program, which is computationally hard to solve. Second, the number of variables is C - the number of configurations, which may be enormous. The KK algorithms cope with these difficulties using several techniques, some of which were already introduced by de-la-Vega and Lueker. Here is a high-level description of the algorithm (where is the original instance):
1-a. Let be an instance constructed from by removing small items.
2-a. Let be an instance constructed from by grouping items and rounding the size of items in each group to the highest item in the group.
3-a. Construct the configuration linear program for , without the integrality constraints.
4. Compute a (fractional) solution x for the relaxed linear program.
3-b. Round x to an integral solution for .
2-b. "Un-group" the items to get a solution for .
1-b. Add the small items to get a solution for .
Below, we describe each of these steps in turn.
Step 1. Removing and adding small items
The motivation for removing small items is that, when all items are large, the number of items in each bin must be small, so the number of possible configurations is (relatively) small. We pick some constant , and remove from the original instance all items smaller than . Let be the resulting instance. Note that in , each bin can contain at most items. We pack and get a packing with some bins.
Now, we add the small items into the existing bins in an arbitrary order, as long as there is room. When there is no more room in the existing bins, we open a new bin (as in next-fit bin packing). Let be the number of bins in the final packing. Then: .Proof. If no new bins are opened, then the number of bins remains . If a new bin is opened, then all bins except maybe the last one contain a total size of at least , so the total instance size is at least . Therefore, , so the optimal solution needs at least bins. So .
In particular, by taking g=1/n, we get:,since . Therefore, it is common to assume that all items are larger than 1/n.
Step 2. Grouping and un-grouping items
The motivation for grouping items is to reduce the number of different item sizes, to reduce the number of constraints in the configuration LP. The general grouping process is:
Order the items by descending size.
Partition the items into groups.
For each group, modify the size of all items in the group to the largest size in the group.
There are several different grouping methods.
Linear grouping
Let be an integer parameter. Put the largest items in group 1; the next-largest items in group 2; and so on (the last group might have fewer than items). Let be the original instance. Let be the first group (the group of the largest items), and the grouped instance without the first group. Then:
In all items have the same size. In the number of different sizes is .
- since group 1 in dominates group 2 in (all k items in group 1 are larger than the k items in group 2); similarly, group 2 in dominates group 3 in , etc.
- since it is possible to pack each item in into a single bin.
Therefore, . Indeed, given a solution to with bins, we can get a solution to with at most bins.
Geometric grouping
Let be an integer parameter. Geometric grouping proceeds in two steps:
Partition the instance into several instances such that, in each instance , all sizes are in the interval . Note that, if all items in have size at least , then the number of instances is at most .
On each instance , perform linear rounding with parameter . Let be the resulting instances. Let and .
Then, the number of different sizes is bounded as follows:
For all r, and . Since all items in are larger than , we have , so . Summing over all r gives .
The number of bins is bounded as follows:
For all r, - since has items, and all of them are smaller than , so they can be packed into at most bins.
Therefore, .
Therefore, .
Alternative geometric grouping
Let be an integer parameter. Order the items by descending size. Partition them into groups such that the total size in each group is at least . Since the size of each item is less than B, The number of items in each group is at least . The number of items in each group is weakly-increasing. If all items are larger than , then the number of items in each group is at most . In each group, only the larger items are rounded up. This can be done such that:
.
.
Step 3. Constructing the LP and rounding the solution
We consider the configuration linear program without the integrality constraints:.Here, we are allowed to use a fractional number of each configuration.
Example: suppose there are 31 items of size 3 and 7 items of size 4, and the bin-size is 10. The configurations are: 4, 44, 34, 334, 3, 33, 333. The constraints are [0,0,1,2,1,2,3]*x=31 and [1,2,1,1,0,0,0]*x=7. An optimal solution to the fractional LP is [0,0,0,7,0,0,17/3] That is: there are 7 bins of configuration 334 and 17/3 bins of configuration 333. Note that only two different configurations are needed.
Denote the optimal solution of the linear program by LOPT. The following relations are obvious:
FOPT(I) ≤ LOPT(I), since FOPT(I) is the (possibly fractional) number of bins when all bins are completely filled with items or fractions of items. Clearly, no solution can be more efficient.
LOPT(I) ≤ OPT(I), since LOPT(I) is a solution to a minimization problem with fewer constraints.
OPT(I) < 2*FOPT(I), since in any packing with at least 2*FOPT(I) bins, the sum of the two least-full bins is at most B, so they can be combined into a single bin.
A solution to the fractional LP can be rounded to an integral solution as follows.
Suppose we have a solution x to the fractional LP. We round x into a solution for the integral ILP as follows.
Let x be an optimal basic feasible solution of the fractional LP. Suppose it as bins (note that may be a fractional number). Since the fractional LP has m constraints (one for each distinct size), x has at most m nonzero variables, that is, at most m different configurations are used. We construct from x an integral packing consisting of a principal part and a residual part.
The principal part contains floor(xc) bins of each configuration c for which xc > 0.
For the residual part (denoted by R), we construct two candidate packings:
A single bin of each configuration c for which xc > 0; all in all m bins are needed.
A greedy packing, with fewer than 2*FOPT(R) bins (since if there are at least 2*FOPT(R) bins, the two smallest ones can be combined).
The smallest of these packings requires min(m, 2*FOPT(R)) ≤ average(m, 2*FOPT(R)) = FOPT(R) + m/2.
Adding to this the rounded-down bins of the principal part yields at most bins.
The execution time of this conversion algorithm is O(n log n).
This also implies that .
Step 4. Solving the fractional LP
The main challenge in solving the fractional LP is that it may have a huge number of variables - a variable for each possible configuration.
The dual LP
The dual linear program of the fractional LP is:.It has m variables , and C constraints - a constraint for each configuration. It has the following economic interpretation. For each size s, we should determine a nonnegative price . Our profit is the total price of all items. We want to maximize the profit n y subject to the constraints that the total price of items in each configuration is at most 1. This LP now has only m variables, but a huge number of constraints. Even listing all the constraints is infeasible.
Fortunately, it is possible to solve the problem up to any given precision without listing all the constraints, by using a variant of the ellipsoid method. This variant gets as input, a separation oracle: a function that, given a vector y ≥ 0, returns one of the following two options:
Assert that y is feasible, that is, ; or -
Assert that y is infeasible, and return a specific constraint that is violated, that is, a vector a such that .
The ellipsoid method starts with a large ellipsoid, that contains the entire feasible domain . At each step t, it takes the center of the current ellipsoid, and sends it to the separation oracle:
If the oracle says that is feasible, then we do an "optimality cut": we cut from the ellipsoid all points y for which . These points are definitely not optimal.
If the oracle says that is infeasible and violates the constraint a, then we do a "feasibility cut": we cut from the ellipsoid all points y for which . These points are definitely not feasible.
After making a cut, we construct a new, smaller ellipsoid. It can be shown that this process converges to an approximate solution, in time polynomial in the required accuracy.
A separation oracle for the dual LP
We are given some m non-negative numbers . We have to decide between the following two options:
For every feasible configuration, the sum of corresponding to this configuration is at most 1; this means that y is feasible.
There exists a feasible configuration for which the sum of is larger than 1; this means that y is infeasible. In this case, we also have to return the configuration.
This problem can be solved by solving a knapsack problem, where the item values are , the item weights are , and the weight capacity is B (the bin size).
If the total value of the optimal knapsack solution is at most 1, then we say that y is feasible.
If the total value of the optimal knapsack solution is larger than 1, then we say that y is infeasible, and the items in the optimal knapsack solution correspond to a configuration that violates a constraint (since for the vector a that corresponds to this configuration).
The knapsack problem can be solved by dynamic programming in pseudo-polynomial time: , where m is the number of inputs and V is the number of different possible values. To get a polynomial-time algorithm, we can solve the knapsack problem approximately, using input rounding. Suppose we want a solution with tolerance . We can round each of down to the nearest multiple of /n. Then, the number of possible values between 0 and 1 is n/, and the run-time is . The solution is at least the optimal solution minus /n.
Ellipsoid method with an approximate separation oracle
The ellipsoid method should be adapted to use an approximate separation oracle. Given the current ellipsoid center :
If the approximate oracle returns a solution with value larger than 1, then is definitely infeasible, and the solution correspond to a configuration that violates a constraint a. We do a "feasibility cut" in , cutting the ellipsoid all points y for which .
If the approximate oracle returns a solution with value at most 1, then may or may not be feasible, but rounded down (denote it by ) is feasible. By definition of the rounding, we know that . We still do an "optimality cut" in : we cut from the ellipsoid all points y for which . Note that might be infeasible, so its value might be larger than OPT. Therefore, we might remove some points whose objective is optimal. However, the removed points satisfy ; no point is removed if its value exceeds the value at by more than .
Using the approximate separation oracle gives a feasible solution y* to the dual LP, with , after at most iterations, where . The total run-time of the ellipsoid method with the approximate separation oracle is .
Eliminating constraints
During the ellipsoid method, we use at most Q constraints of the form . All the other constraints can be eliminated, since they have no effect on the outcome y* of the ellipsoid method. We can eliminate even more constraints. It is known that, in any LP with m variables, there is a set of m constraints that is sufficient for determining the optimal solution (that is, the optimal value is the same even if only these m constraints are used). We can repeatedly run the ellipsoid method as above, each time trying to remove a specific set of constraints. If the resulting error is at most , then we remove these constraints permanently. It can be shown that we need at most eliminations, so the accumulating error is at most . If we try sets of constraints deterministically, then in the worst case, one out of m trials succeeds, so we need to run the ellipsoid method at most times. If we choose the constraints to remove at random, then the expected number of iterations is .
Finally, we have a reduced dual LP, with only m variables and m constraints. The optimal value of the reduced LP is at least , where .
Solving the primal LP
By the LP duality theorem, the minimum value of the primal LP equals the maximum value of the dual LP, which we denoted by LOPT. Once we have a reduced dual LP, we take its dual, and take a reduced primal LP. This LP has only m variables - corresponding to only m out of C configurations. The maximum value of the reduced dual LP is at least . It can be shown that the optimal solution of the reduced primal LP is at most . The solution gives a near-optimal bin packing, using at most m configurations.
The total run-time of the deterministic algorithm, when all items are larger than , is:
,
The expected total run-time of the randomized algorithm is: .
End-to-end algorithms
Karmarkar and Karp presented three algorithms, that use the above techniques with different parameters. The run-time of all these algorithms depends on a function , which is a polynomial function describing the time it takes to solve the fractional LP with tolerance h=1, which is, for the deterministic version,.
Algorithm 1
Let be a constant representing the desired approximation accuracy.
1-a. Set . Let be an instance constructed from by removing all items smaller than g.
2-a. Set . Let be an instance constructed from by linear grouping with parameter k, and let be the remaining instance (the group of k largest items). Note that .
3-a. Construct the configuration linear program for , without the integrality constraints.
4. Compute a solution x for , with tolerance h=1. The result is a fractional bin packing with bins. The run-time is .
3-b. Round x to an integral solution for . Add at most bins for the fractional part. The total number of bins is .
2-b. Pack the items in using at most k bins; get a packing of . The number of bins is .
1-b. Add the items smaller than g to get a solution for . The number of bins is: .
All in all, the number of bins is in and the run-time is in . By choosing we get .
Algorithm 2
Let be a real parameter and an integer parameter to be determined later.
1-a. Let be an instance constructed from by removing all items smaller than g.
2. While do:
2-a. Do the Alternative Geometric Grouping with parameter k. Let be the resulting instance, and let be the remaining instance. We have .
3-a. Construct the configuration linear program for , without the integrality constraints.
4. Compute a solution x for , with tolerance h=1. The result is a fractional bin packing with bins. The run-time is .
3-b. Round x to an integral solution for . Do not add bins for the fractional part. Instead, just remove the packed items from .
2-b. Pack the items in in at most bins.
2. Once , pack the remaining items greedily into at most bins.
At each iteration of the loop in step 2, the fractional part of x has at most m(K) patterns, so . The FOPT drops by a factor of k in each iteration, so the number of iterations is at most .
Therefore, the total number of bins used for is: .
1-b. Add the items smaller than g to get a solution for . The number of bins is: .
The run-time is in .
Now, if we choose k=2 and g=1/FOPT(I), we get:, and hence:, so the total number of bins is in . The run-time is .
The same algorithm can be used with different parameters to trade-off run-time with accuracy. For some parameter , choose and . Then, the packing needs at most bins, and the run-time is in .
Algorithm 3
The third algorithm is useful when the number of sizes m is small (see also high-multiplicity bin packing).
1-a. Set . Let be an instance constructed from by removing all items smaller than g.
If then:
3-a. Construct the configuration linear program for , without the integrality constraints.
4. Compute a solution x for , with tolerance h=1. The result is a fractional bin packing with bins. The run-time is .
3-b. Round x to an integral solution for . Do not add bins for the fractional part. Instead, just remove the packed items from .
Run step 2 of Algorithm 2 on the remaining pieces.
1-b. Add the items smaller than g to get a solution for . The number of bins is: .
It uses at most bins, and the run-time is in .
Improvements
The KK techniques were improved later, to provide even better approximations.
Rothvoss uses the same scheme as Algorithm 2, but with a different rounding procedure in Step 2. He introduced a "gluing" step, in which small items are glued together to yield a single larger item. This gluing can be used to increase the smallest item size to about . When all sizes are at least , we can substitute in the guarantee of Algorithm 2, and get:, which yields a bins.
Hoberg and Rothvoss use a similar scheme in which the items are first packed into "containers", and then the containers are packed into bins. Their algorithm needs at most bins.
References
Bin packing | Karmarkar–Karp bin packing algorithms | [
"Mathematics"
] | 4,641 | [
"Bin packing",
"Mathematical problems",
"Packing problems"
] |
69,710,383 | https://en.wikipedia.org/wiki/Materials%20Science%20and%20Engineering%20A | Materials Science and Engineering: A — Structural Materials: Properties, Microstructure and Processing is a peer-reviewed scientific journal. It is the section of Materials Science and Engineering dedicated to "theoretical and experimental studies related to the load-bearing capacity of materials as influenced by their basic properties, processing history, microstructure and operating environment" and is published monthly by Elsevier. The current editor-in-chiefs are H. W. Hahn (University of Oklahoma), E. J. Lavernia (Texas A&M University), and B. B. Wei (Northwestern Polytechnical University).
Abstracting and indexing
The journal is indexed and abstracted in the following bibliographic databases:
According to the Journal Citation Reports, the journal has a 2022 impact factor of 6.4, ranking 9th out of 79 in the category 'Metallurgy & Metallurgical Engineering'.
References
External links
Physics review journals
Materials science journals
Elsevier academic journals
Academic journals established in 1993
English-language journals
Monthly journals | Materials Science and Engineering A | [
"Materials_science",
"Engineering"
] | 211 | [
"Materials science journals",
"Materials science"
] |
69,712,039 | https://en.wikipedia.org/wiki/Terbium%20phosphide | Terbium phosphide is an inorganic compound of terbium and phosphorus with the chemical formula TbP.
Synthesis
TbP can be obtained by the reaction of terbium and red phosphorus at 800–1000 °C:
4 Tb + P4 → 4 TbP
The compound can also be obtained by the reaction of sodium phosphide and anhydrous terbium chloride at 700~800 °C.
Physical properties
TbP undergoes a phase transition at 40 GPa from a NaCl-structure to a CsCl-structure. The compound can be sintered with zinc sulfide to make a green phosphor layer.
TbP forms crystals of a cubic system, space group Fm3m.
Uses
The compound is a semiconductor used in high power, high frequency applications and in laser diodes and other photo diodes.
References
Phosphides
Terbium compounds
Semiconductors
Rock salt crystal structure | Terbium phosphide | [
"Physics",
"Chemistry",
"Materials_science",
"Engineering"
] | 187 | [
"Electrical resistance and conductance",
"Physical quantities",
"Semiconductors",
"Materials",
"Electronic engineering",
"Condensed matter physics",
"Solid state engineering",
"Matter"
] |
69,712,429 | https://en.wikipedia.org/wiki/Gadolinium%20phosphide | Gadolinium phosphide is an inorganic compound of gadolinium and phosphorus with the chemical formula GdP.
Synthesis
Gadolinium phosphide can be obtained by reacting gadolinium and phosphorus at high temperature, and single crystals can be obtained by mineralization.
4 Gd + P4 → 4 GdP
Physical properties
GdP has a NaCl-structure and transforms to a CsCl-structure at 40 GPa.
GdP forms crystals of a cubic system, space group Fm3m.
Gadolinium phosphide is antiferromagnetic.
Uses
The compound is a semiconductor used in high power, high frequency applications and in laser diodes.
References
Phosphides
Gadolinium compounds
Semiconductors
Rock salt crystal structure | Gadolinium phosphide | [
"Physics",
"Chemistry",
"Materials_science",
"Engineering"
] | 157 | [
"Electrical resistance and conductance",
"Physical quantities",
"Semiconductors",
"Materials",
"Electronic engineering",
"Condensed matter physics",
"Solid state engineering",
"Matter"
] |
69,712,603 | https://en.wikipedia.org/wiki/2-Acetylthiophene | 2-Acetylthiophene is an organosulfur compound with the formula CH3C(O)C4H3S. A yellow liquid, it is the more useful of the two isomers of acetylthiophene. It is of commercial interest as a precursor to both thiophene-2-carboxylic acid and thiophene-2-acetic acid. It is prepared by the reaction of thiophene with acetyl chloride in the presence of stannic chloride.
References
Thiophenes
Carboxylic acids | 2-Acetylthiophene | [
"Chemistry"
] | 122 | [
"Carboxylic acids",
"Functional groups"
] |
69,712,687 | https://en.wikipedia.org/wiki/Thiophene-2-acetic%20acid | Thiophene-2-acetic acid is the organosulfur compound with the formula HO2CCH2C4H3S. Together with thiophene-3-acetic acid, it is one of two isomeric thiophene acetic acids.
Preparation and use
It is prepared from 2-acetylthiophene.
It is a precursor to the antibiotics cephaloridine and cephalothin.
References
Thiophenes
Carboxylic acids | Thiophene-2-acetic acid | [
"Chemistry"
] | 105 | [
"Carboxylic acids",
"Functional groups"
] |
69,714,408 | https://en.wikipedia.org/wiki/Fran%C3%A7ois%20M.%20M.%20Morel | François M. M. Morel (born 11 October 1944) is a French-American biogeochemist. He is known for his research on ocean acidification, mercury pollution, the only known cadmium metalloenzyme, and the interactions between trace metals and microorganisms.
Early life and education
Morel grew up in Versailles, France. Morel attended the University of Grenoble, France and earned his B.S. in Applied Mathematics in 1966. He went on to earn his Diplôme d’Ingénieur the next year in 1967. In 1971, Morel obtained a Ph.D. in Engineering Sciences from California Institute of Technology.
Research and career
From 1973 to 1994, Morel was a faculty member of the Massachusetts Institute of Technology's Department of Civil and Environmental Engineering, and, from 1994 to 2018, he was a professor in Princeton University's Department of Geosciences. His research and that of his students and postdoctoral researchers dealt the interactions between the chemical composition of natural waters and aquatic microorganisms. The development of computational methods to quantify the reactions among the many chemical species in aquatic systems provided the means to study quantitatively the interactions between microbes and chemical elements and compounds present in natural waters, with a focus on essential metals that are required for the growth of phytoplankton. This work encompassed the cycling and methylation of mercury, the contributions of metals to the nitrogen cycle, the use of cadmium by marine microalgae, the uptake mechanisms of iron and zinc by plankton, and the effects of ocean acidification on microorganisms.
REDEQL
As a postdoctoral fellow in Environmental Engineering Sciences from 1971-1973, Morel collaborated with James (Jim) J. Morgan to produce the computer program REDEQL (where RED stands for "redox" and EQL stands for "equilibrium"), which computed complex chemical equilibria in natural waters and man-made chemical systems. Morel and Morgan's creation of REDEQL was supported by the United States Environmental Protection Agency and was widely adopted and built upon.
Ocean acidification
In 2009, Morel chaired the Committee on the Development of an Integrated Science Strategy for Ocean Acidification Monitoring, Research, and Impacts Assessment. This committee published the report Ocean Acidification: A National Strategy to Meet the Challenges of a Changing Ocean, which detailed the unprecedented acidifying of the ocean's pH due to anthropogenic carbon dioxide emissions, the potential adverse impacts on marine organisms dependent on calcium carbonate, and the need for more information and international cooperation.
Appointments
Morel founded and directed the Center for Environmental BioInorganic Chemistry from 1998 to 2007. From 1998–2004 and from 2014–2017, Morel served as the director of Princeton Environmental Institute, which was later renamed to the High Meadows Environmental Institute in 2020.
Retirement
Morel retired in 2018.
Awards and honors
1987 Paul V. Roberts/Association of Environmental Engineering & Science Professors Outstanding Doctoral Dissertation Award Advisor
1994 Association of Environmental Engineering & Science Professors Outstanding Publication Award Recipient
2000 Geochemical Society Fellow Honor Recipient
2001 Guggenheim Fellowship Recipient
2001 Geochemical Society C.C. Patterson Award Recipient
2005 American Geophysical Union Maurice Ewing Medal Recipient
2005 Elected Fellow of the American Geophysical Union
2009 Caltech Distinguished Alumni Award Recipient
2009 Elected Member of the National Academy of Sciences
2009 European Association of Geochemistry H.C. Urey Award Recipient
2010 Eni Award Recipient
2011 American Chemical Society Award for Creative Advances in Environmental Science and Technology Recipient
2011 Elected Member of the Istituto Veneto di Scienze, Lettere ed Arti
2012 Carnegie Mellon University Dickson Prize Recipient
Selected publications
Xu Y., L.Feng, P.D. Jeffrey, Y.G. Shi and F. M. M Morel, Structure and metal exchange in the cadmium carbonic anhydrase of marine diatoms. Nature, 452: 56–61 (2008). 10.1038/nature06636
Hopkinson, B.M., C.L. Dupont, A.E. Allen and F. M. M. Morel. Efficiency of the CO2 concentrating mechanism of diatoms. PNAS, 108 (10) 3830–3837. (2011)
Shaked, Y., A.B. Kustka and F. M. M. Morel. A general kinetic model for iron acquisition by eukaryotic phytoplankton. Limnology & Oceanography, 50(3): 872–882 (2005).
Schaefer, J.K., and F. M. M. Morel. High methylation rates of mercury bound to cysteine by Geobacter sulfurreducens. Nature Geoscience. (2009)
Shi, D., Y. Xu, B.M. Hopkinson, and F. M. M. Morel. Effect of ocean acidification on iron availability to marine phytoplankton. Science 327: 676–679 (2010)
Price, N.M., B.A. Ahner and F. M. M. Morel. The Equatorial Pacific Ocean: grazer-controlled phytoplankton populations in an iron-limited ecosystem. Limnology & Oceanography, 39: 520–534 (1994).
Farley, K.J., D.A. Dzombak and F. M. M. Morel. A surface precipitation model for the sorption of cations on metal oxides. J. Coll. Inter. Sci. 106:1 (1985).
Waite, T.D. and F. M. M. Morel. Photoreductive dissolution of colloidal iron oxide: Effect of citrate. J. Coll. Inter. Sci. 102:1 (1984).
Kraepiel, A.M.L., K. Keller, and F. M. M. Morel. A model for metal adsorption on clays. J.Colloid and Interface Science, 210: 43–54 (1999).
Price, N.M., B.A. Ahner and F. M. M. Morel. The Equatorial Pacific Ocean: grazer-controlled phytoplankton populations in an iron-limited ecosystem. Limnology & Oceanography, 39: 520–534 (1994).
References
Living people
Wikipedia Student Program
People from Versailles
Grenoble Alpes University alumni
California Institute of Technology alumni
MIT School of Engineering faculty
Princeton University faculty
Biogeochemists
1944 births | François M. M. Morel | [
"Chemistry"
] | 1,361 | [
"Geochemists",
"Biogeochemistry",
"Biogeochemists"
] |
69,714,477 | https://en.wikipedia.org/wiki/Edith%20Wilson%20Miles | Edith Wilson Miles (born Edith Margaret Wilson) is a biochemist known for her work on the structure and function of enzymes, especially her work on tryptophan synthase.
Education and career
Miles received her B.A. from the University of Texas at Austin in 1957, and then moved to the University of California, Berkeley where she earned a Ph.D. in 1962 working in Esmond Emerson Snell's lab with Jesse Rabinowitz and Edward Adelberg as her advisors. With funding from the American Cancer Society, she moved to the University of Leicester as a postdoctoral researcher with Hans Kornberg. From 1964 until 1966, she was a postdoctoral investigator at Tufts University working with Alton Meister, and then she accepted an independent position at the National Institutes of Health. In 2000 she became a Scientist Emeritus.
Research
Wilson's graduate research characterized an enzyme that required pyridoxal phosphate and tetrahydrofolate to convert -methylserine to alanine and formaldehyde. Her subsequent work examined the glyoxylate cycle in bacterial cells and led to further investigation of enzymes that require pyridoxal phosphate. Upon her move to the National Institutes of Health, she began to focus on tryptophan synthase, first by establishing the mechanism of the enzyme which would later allow her to investigate interactions between the subunits of the enzyme. Wilson went on to use x-ray crystallography to obtain the structure of the enzyme, and used mutant forms of Salmonella typhimurium to identify the significant components of the enzyme. She also showed that complex of tryptophan synthase could unfold in the presence of guanine hydrochloride, details about protein folding and shape that became relevant in later research about barrel-shaped proteins.
Selected publications
Awards and honors
While at the University of Texas at Austin, Miles (then known as Edith Margaret Wilson) was inducted into Alpha Lambda Delta, an honor society that recognizes achievement of first year university students and for which she later served as secretary. In her senior year, 1957, she was elected to Phi Beta Kappaand was a member of Mortar Board. In 1994, Miles received the Hillebrand Award, named for William Francis Hillebrand, from the Chemical Society of Washington, a section of the American Chemical Society.
Personal life
Her husband, H. Todd Miles, also worked at the National Institutes of Health and became Scientist Emeritus in 2000.
References
University of Texas at Austin alumni
University of California, Berkeley alumni
National Institutes of Health faculty
Women biochemists
Living people
21st-century American women
Year of birth missing (living people) | Edith Wilson Miles | [
"Chemistry"
] | 534 | [
"Biochemists",
"Women biochemists"
] |
69,715,565 | https://en.wikipedia.org/wiki/Antonia%20Trichopoulou | Antonia Trichopoulou (; born 1938) is a nutrition epidemiologist, specialising in the study of the health effects of the Mediterranean diet. She has been called the "mother of the Mediterranean Diet". Trichopoulou is a Professor Emeritus of the School of Medicine of the University of Athens and the President of the Hellenic Health Foundation.
She has published more than 900 scientific papers and was president of the Federation of European Nutrition Societies (FENS). For her contributions, she was elected in December 2021 a full member of the Academy of Athens in the Chair of "Medical Sciences: Epidemiology and Public Health". In 2003 she was awarded the Golden Cross of Honor by the President of the Greek Republic.
Her late husband was Dimitrios Trichopoulos, a cancer epidemiologist.
Early life and education
Trichopoulou was born in Athens, Greece. In 1961, she graduated as a medical doctor from the Medical School of the University of Athens. In 1963, she received her degree from the Athens School of Health and in 1965 she completed the specialty of biopathology (microbiology). She was awarded her doctorate in medicine from the University of Athens.
Career
In 1976 Trichopoulou became a professor of medicine at the University of Athens, in the field of biological chemistry. She was appointed professor of nutrition and biochemistry at the Athens School of Public Health in 1977 and served as Dean of the School from 1985 to 1987.
In 1994 she was awarded the title of adjunct professor of nutrition at the Harvard School of Public Health, Boston, USA. During her career at the Athens School of Public Health (1990–1999) and then at the Laboratory of Hygiene and Epidemiology of the University of Athens (2000–2019), she headed the World Health Organization's Collaborating Centre for Nutrition.
In 2006, she co-founded the non-profit Hellenic Health Foundation, where she has been President since 2014. For her contributions, she was elected in December 2021 a full member of the Academy of Athens in the Chair of "Medical Sciences: Epidemiology and Public Health".
Trichopoulou's research mainly focuses on nutrition and particularly, the Mediterranean diet. She developed the first standardized score for adherence to the traditional Mediterranean diet, the Mediterranean Diet Score (MDS). The MDS, or its variations, has been used in hundreds of studies evaluating the health effects of adherence to the Mediterranean diet all over the world.
Awards and honors
Trichopoulou has received numerous awards and honors, including:
Golden Cross of Honor, President of the Greek Republic, 2003
Award for her outstanding nutritionist career, Federation of European Nutrition Societies (FENS), 2011
Full member, Chair of Medical Sciences: Epidemiology and Public Health, Academy of Athens, 2021
Further engagements
Apart from her published manuscripts and her engagements in various scientific bodies, she has also discussed her work in interviews and podcasts.
References
Greek public health doctors
Greek biochemists
Nutritionists
Members of the Academy of Athens (modern)
Mediterranean diet advocates
World Health Organization officials
Academic staff of the National and Kapodistrian University of Athens
Harvard T.H. Chan School of Public Health faculty
Academic staff of the University of West Attica
National and Kapodistrian University of Athens alumni
University of West Attica alumni
1938 births
Living people
Place of birth missing (living people)
20th-century Greek women physicians
Women nutritionists
Women biochemists
Women epidemiologists
People from Athens
Women public health doctors
20th-century Greek women scientists
20th-century Greek scientists
21st-century Greek women scientists
21st-century Greek scientists | Antonia Trichopoulou | [
"Chemistry"
] | 736 | [
"Biochemists",
"Women biochemists"
] |
69,715,647 | https://en.wikipedia.org/wiki/Ruler%20function | In number theory, the ruler function of an integer can be either of two closely related functions. One of these functions counts the number of times can be evenly divided by two, which for the numbers 1, 2, 3, ... is
Alternatively, the ruler function can be defined as the same numbers plus one, which for the numbers 1, 2, 3, ... produces the sequence
As well as being related by adding one, these two sequences are related in a different way: the second one can be formed from the first one by removing all the zeros, and the first one can be formed from the second one by adding zeros at the start and between every pair of numbers. For either definition of the ruler function, the rising and falling patterns of the values of this function resemble the lengths of marks on rulers with traditional units such as inches. These functions should be distinguished from Thomae's function, a function on real numbers which behaves similarly to the ruler function when restricted to the dyadic rational numbers.
In advanced mathematics, the 0-based ruler function is the 2-adic valuation of the number, and the lexicographically earliest infinite square-free word over the natural numbers. It also gives the position of the bit that changes at each step of the Gray code.
In the Tower of Hanoi puzzle, with the disks of the puzzle numbered in order by their size, the 1-based ruler function gives the number of the disk to move at each step in an optimal solution to the puzzle. A simulation of the puzzle, in conjunction with other methods for generating its optimal sequence of moves, can be used in an algorithm for generating the sequence of values of the ruler function in constant time per value.
References
External links
Calculus
Special functions
Number theory | Ruler function | [
"Mathematics"
] | 361 | [
"Discrete mathematics",
"Special functions",
"Calculus",
"Number theory stubs",
"Combinatorics",
"Number theory"
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78,589,697 | https://en.wikipedia.org/wiki/IC%204263 | IC 4263 an edge-on barred spiral galaxy in the constellation Canes Venatici. Its velocity relative to the cosmic microwave background is 2,887 ± 13 km/s , which corresponds to a Hubble distance of 42.6 ± 3.0 Mpc (∼139 million light years ). It was discovered by American astronomer James Edward Keeler in 1899.
IC 4263 is class IV in luminosity and has a broad HI 1 line. With a surface brightness of 14.20 mag / am 2, IC 4263 can be described as a low surface brightness (LSB) galaxy. LSB galaxies are diffuse (D) galaxies with a surface brightness less than one magnitude lower than that of the ambient night sky.
To date, six non-redshift measurements give a distance of 40.150 ± 2.601 Mpc (∼131 million lightyears), which is within the Hubble distance values.
References
External links
IC 4263 on WikiSky
IC 4263 Website of Prof C. Seligman
Barred spiral galaxies
Canes Venatici
4263
Astronomical objects discovered in 1899 | IC 4263 | [
"Astronomy"
] | 234 | [
"Canes Venatici",
"Constellations"
] |
78,590,623 | https://en.wikipedia.org/wiki/Diradicaloid | Biradicaloids or diradicaloids are molecules with two radical electrons that have significant interaction with each other. The two unpaired electrons are coupled and can either form a singlet ground state (antiferromagnetic coupling) or a triplet ground state (ferromagnetic coupling) (Figure 1).
This is in contrast to "disbiradicals," where the two radical electrons have no significant interaction and act independently as isolated radical species. Diradicals are characterized by their diradical character, commonly quantified using an indicator . In the limit of fully degenerate frontier molecular orbitals, approaches a value of 1, representing 100% diradical character. However, diradicaloids have a small gap between the highest occupied molecular orbital (HOMO) and the lowest occupied molecular orbital (LUMO) and thus can be described as having incomplete diradical character, generally corresponding to a value of between 0.20 and 0.80. Diradicals have historically been characterized as transient species describing the transition state of a bond breaking and/or making process, but recently, the introduction of steric strain to prevent bond formation and substitution of carbon atoms with main-group elements have been found to significantly stabilize diradical species, leading to their isolation and structural characterization. However, these modifications decrease diradical character, leading these species to be more properly designated as diradicaloids. Diradicaloids have found applications in small molecule activation, molecular switching, nonlinear optics, and spintronics.
Theoretical description
Electronic structure
Due to the coupling interaction between the radical electrons in a diradical(oid) species, they cannot be simply described as the union of two independent radical centers. Both the open-shell singlet and triplet states must be considered to fully describe the electronic structure of diradical(oid) species.
The triplet state wavefunction can be described as a single electronic configuration with a single Slater determinant. However, when the frontier molecular orbitals are degenerate or nearly degenerate, the lowest-energy singlet state wavefunction must account for multiple electronic configurations (see electronic correlation). Thus, is most accurately represented as a combination of Slater determinants. Here, the configuration interaction (CI) coefficients and define the contribution of each determinant to the total wavefunction, where refers to the HOMO and refers to the LUMO:
When , and are degenerate, and the singlet wavefunction describes a perfect diradical. As the HOMO-LUMO gap increases, the wavefunction approaches that of a classical closed-shell species; approaches 1 and approaches 0 so that the lowest-energy singlet state is dominated by the doubly occupied HOMO.
To gain a more intuitive understanding of the diradical nature of the wavefunction, the triplet and singlet wavefunctions can be represented using a localized orbital basis, where and are the two localized orbitals (Figure 2). Assuming and are orthogonal, the overlap integral becomes 0. The HOMO can be decomposed into the in-phase overlap of and , while the LUMO can be decomposed into the out-of-phase overlap of and :
Consequently, the singlet wavefunction can be expressed as the combination of a covalent contribution and an ionic contribution . The covalent component represents the electron configuration in which both localized orbitals are singly occupied; this corresponds to diradical character. The ionic component represents the electron configuration in which one localized orbital is doubly occupied, leaving the other localized orbital empty; this corresponds to zwitterionic character:
where and
When , and ; thus, this situation describes 100% diradical character. As the HOMO-LUMO gap increases, approaches 1 and approaches 0, which results in ; thus, this situation reduces to the complete delocalization of the electrons over the two-orbital system, which is equivalent to the electron configuration of the closed-shell species.
Indicators of diradical character
The CI coefficients and can be used to provide a quantification of diradical character. Some common indicators are listed below:
All of the above indicators () effectively describe how much greater the relative weight of the covalent contribution is to the singlet wavefunction compared to the ionic contribution. Thus, the greater the values of these indicators, the greater the diradical character. In the limit of 100% diradical character, these indicators approach a value of 1; in the limit of 100% classical closed-shell character, these indicators approach a value of 0.
Natural orbital (NO) occupation numbers are also another theoretical indicator of diradical character. The occupancy of the lowest unoccupied NO is equal to the indicator and ranges from 0 to 1; the closer the calculated occupancy is to 1, the greater the predicted diradical character. On the other hand, the occupancy of the highest occupied NO ranges from 1 to 2; the closer the calculated occupancy is to 1, the greater the predicted diradical character. These natural orbital occupancy numbers can be calculated using almost all computational methods and therefore can often be obtained with less computational cost than calculating using CI methods.
A small singlet-triplet energy gap can also indicate increased diradical character. Lastly, if the calculated A-B distance (where A and B are the two radical centers) is elongated compared to the sum of the covalent radii (the typical A-B distance of a closed-shell molecule) but is shorter than the sum of the van der Waals radii, this may also suggest the presence of a diradicaloid. Incorporating sterically bulky substituents and introducing ring strain in heterocycles can help to prevent bond formation and/or generate elongated bonds.
Synthesis
Cyclobutane-1,3-diyl analogues
Cyclobutane-1,3-diyl
Cyclobutane-1,3-diyl is the planar four-membered carbon ring species with radical character localized at the 1 and 3 positions. The singlet cyclobutane-1,3-diyl is predicted to be the transition state for the ring inversion of bicyclobutane, proceeding via homolytic cleavage of the transannular carbon-carbon bond (Figure 3).
A 1,3-dimethyl substituted derivative in the triplet state was detected by electron paramagnetic resonance spectroscopy; the diradical species was generated via irradiation of the precursor diazo compound below 25 K in a solid matrix (Figure 4). However, the all-carbon cyclobutane-1,3-diyl is very short-lived and quickly reacts to form the bicyclobutane isomer.
1,3-diphospha-cyclobutane-2,4-diyl
In 1995, Niecke and coworkers reported the first synthesis of a phosphorus analog of cyclobutane-1,3-diyl, [ClC(μ-PMes*)]2. This species consists of a [P2C2]-four-membered heterocycle with radical character centered on the two carbon atoms. The heterocycle was synthesized from the reaction of aryl(dichloromethylene)phosphene (aryl = Mes*, supermesityl) with n-butyllithium in a 2:1 ratio, followed by elimination of LiCl (Figure 5). X-ray diffraction revealed that that the [P2C2] unit exists in the planar four-membered ring form, rather than as the bicyclic isomer. MCSCF calculations predicted a singlet ground state. In addition, the calculated CI wavefunction has contributions from both the doubly occupied HOMO state and the doubly occupied LUMO state; this corresponded to occupation of the HOMO with 1.6 electrons, indicating considerable diradical character. The diphosphacyclobutane heterocycle is thermally stable, and transannular C-C bond formation is thermally forbidden according to the Woodward-Hoffmann rules. Heating at 100 °C in toluene led to the cleavage of the P-C bond, likely generating a ring-opened carbene intermediate that subsequently performed intramolecular C-H activation.
Another synthetic route was developed by Yoshifuji and Ito to access a wider variety of substituents at phosphorus (Figure 7). 2 equivalents of Mes*-substituted phosphaalkyne can be reacted with the lithiated compound of the first substituent on phosphorus, forming the anionic [P2C2] four-membered ring. This intermediate can then be alkylated to attach the second phosphorus substituent. This two-step synthetic pathway allows for the synthesis of unsymmetrically substituted 1,3-diphospha-cyclobutane-2,4-diyls. The substituents on carbon are limited to Mes*, however, due to the limitation of the phosphaalkyne starting material. Most diradicaloids of this type can be handled in air and display high kinetic stability due to the steric protection provided by the Mes* substituents on the carbon radical centers.
1,3-diaza-2,4-dipnicta-cyclobutane-2,4-diyl
These diradical species consist of a [Pn1(μ-NR)2Pn2] heterocyclic core (Pn = pnictogen) where the radical sites are centered on the pnictogen atoms. The presence of a nitrogen atom in the heterocycle is thought to stabilize the planar form relative to the bicyclic isomer. This is believed to result from the inability of Pn-Pn bond formation in the bicyclobutane form to energetically compensate for the increase in Pn-N-Pn angle strain; consequently, the planar form, which allows for larger Pn-N-Pn angles, is more stable. The lack of electron delocalization found in calculations suggests that aromaticity from the presence of 6π electrons does not play a significant role in stabilization of the planar isomers.
In 2011, Schulz and coworkers synthesized the first example of a [P2N2] four-membered ring diradicaloid (here, Pn = phosphorus) with meta-terphenyl and hypersilyl substituents on the nitrogen atoms. The synthetic route begins with the chlorinated P2N2 heterocycle, which is then reduced to the diradicaloid with relatively mild titanium(II) or titanium(III) reducing agents (Figure 8). The bulky terphenyl and hypersilyl groups provide kinetic stabilization, preventing dimerization. The terphenyl-substituted diradicaloid is almost indefinitely stable under argon atmosphere at ambient temperatures as a solid and in solvent. The crystal structure reveals a planar [P2N2] four-membered ring and a long distance between the two phosphorus atoms (2.6186 Å compared to 2.22 Å, the sum of covalent radii), indicating no significant transannular interactions. Computations also support the diradical character of this species and predict a singlet ground state. The calculated CI wavefunction has contributions from both the doubly occupied HOMO state and the doubly occupied LUMO state; this corresponds to occupation of the HOMO with 1.7 electrons, indicating considerable diradical character.
Using a similar synthetic route, the arsenic analogue was also synthesized from the chlorinated precursor; reduction using magnesium metal generated the arsenic centered diradicaloid. The crystal structure confirmed a long As-As distance, and EPR spectroscopy indicated a singlet ground state. A mixed phosphorus-arsenic diradicaloid was also reported in 2015, the first with different radical centers. The crystal structure revealed a kite-shaped planar four membered ring with a transannular As-P distance of 2.790 Å, which is shorter than the sum of van der Waals radii (3.65 Å) but longer than the sum of covalent radii (2.32 Å).
Heavier derivatives (where Pn = antimony and bismuth) were observed in situ but could not be isolated due to rapid decomposition to the allyl analogues in the presence of magnesium; however, the corresponding diradicaloids could be trapped through [2+2] cycloadditions with alkynes, thereby providing evidence for their existence. Calculations suggest that the antimony and bismuth-centered diradicaloids have higher diradical character than the lighter pnictogen analogues due to the singlet-triplet energy gap decreasing with heavier, larger pnictogens.
Other hetero-cyclobutane-1,3-diyls
In 2002, Bertrand and coworkers synthesized the first 1,3-diphospha-2,4-dibora-cyclobutane-2,4-diyl, in which the diradical character is localized on the boron atoms. In 2009, Schnöckel and coworkers reported the synthesis of a heavier aluminum-centered diradical analog. A silicon-centered diradical (1,3-diaza-2,4-disilacyclobutane-2,4-diyl) is also known, synthesized by Sekiguchi and coworkers in 2011. An analog in which the nitrogen atoms are replaced with carbon, as well as an all-silicon cyclobutane-1,3-diyl, have been synthesized. In 2004, Power and coworkers reported the synthesis of a germanium-centered diradical, the heavier analog of Sekiguchi's silicon diradical. The corresponding tin-centered diradicals have also been synthesized by Lappert and coworkers in 2004. In 2017, N-heterocyclic carbene-stabilized phosphorus-centered diradicals were reported; like the Niecke-type diradicaloid, the core heterocycle is a [P2C2] four-membered ring, but the radical centers are located on phosphorus rather than carbon. Lastly, one of the first hetero-cyclobutanediyl derivates synthesized is N2S2, disulfur dinitride, but its diradical character has been widely discussed in the literature and is still disputed today.
Cyclopentane-1,3-diyl analogues
Cyclopentane-1,3-diyl
Cyclopentane-1,3-diyl is the planar five-membered carbon ring species with radical character localized at the 1 and 3 positions. The triplet diradical was detected by EPR spectroscopy; the diradical species was generated via irradiation of the precursor diazo compound at 5.5 K in a solid matrix (Figure 11). Due to its very short lifetime, all-carbon cyclopentane-1,3-diyl cannot be isolated, but heating cyclopentane-1,3-diyl leads to the formation of a transannular C-C bond, producing the housane isomer. While the triplet state is predicted to be an energy minimum, the singlet state is predicted to be the transition state for housane inversion.
Hetero-cyclopentane-1,3-diyls
Five-membered diradicals with radical character localized on pnictogen atoms can be synthesized via the insertion of carbon monoxide and isonitriles into the corresponding pnictogen-centered cyclobutane-1,3-diyls. In 2015, Schulz and coworkers reported the first stable cyclopentane-1,3-diyl species generated from the ring expansion of terphenyl-substituted diphosphadiazanediyl using carbon monoxide (Figure 12). The computed structural data support an almost planar five-membered ring, and the HOMO/LUMO contributions to the CI wavefunction indicate an occupation of the HOMO with 1.44 electrons, suggesting diradical character. Experimentally, additions of phosphaalkyne and elemental sulfur across the phosphorus atom are consistent with diradicaloid reactivity.
Isonitriles can also insert into the same diphosphadiazanediyls to form the corresponding heterocyclic 5-membered diradicaloids (Figure 13a). The insertion reaction is sensitive to the steric bulk of the substituent on the isonitrile; for example, the terphenyl-substituted isonitrile was unable to undergo the insertion reaction, while the smaller 2,6-dimethylphenyl isonitrile was able to insert into the P-N bond.
Isonitrile insertion was also explored with mixed phosphorus-nitrogen and phosphorus-arsenic centered 4-membered ring diradicaloids. With the latter compound, the isonitrile selectively inserts into the arsenic-nitrogen bond over the phosphorus-nitrogen bond (Figure 13b). The resulting five-membered ring species was characterized via X-ray structural analysis, confirming the above connectivity (Figure 14). Calculations revealed a substantial diradical character (=0.24), which agrees with the experimentally observed activation of triple bonds.
Other main group diradicaloids
Diradicaloid 6-membered heterocycles have been reported. In 2020, a cyclic alkylaminocarbene-stabilized 9,10-diboraanthracene was synthesized. EPR spectroscopy and quantum calculations indicated a singlet diradical ground state, and the incorporation of boron atoms was demonstrated to lower the HOMO-LUMO band gap. In 2021, a cyclic germanium-centered diradicaloid with a [C4Ge2] framework was isolated. Calculations indicated a singlet diradical ground state, and the ability of the germanium species to split dihydrogen at room temperature further supported its diradical character.
A 1,2-diborete diradicaloid containing a highly strained [B2C2] framework was reported by Braunschweig and coworkers in 2022. In 2024, the first diborepin diradicals, in which the boron radical sites are disjointed, were synthesized by Gilliard and coworkers.
Reactivity
Diradicaloids, depending on the reaction conditions and extent of diradical character, can display both closed-shell and open-shell reactivity. Closed-shell reactivity (e.g., pericyclic reactions) is best understood using the delocalized molecular orbital picture, while open-shell reactivity (e.g., radical additions) is best understood using the localized atomic orbital picture.
Closed-shell reactivity
For example, the phosphorus-centered diradicaloid [P(μ-NTer)2]2 can undergo concerted pericyclic reactions with single bonds (H2), double bonds (alkenes, aldehydes), and triple bonds (alkynes, nitriles) (Figure 15). Only the cis-addition products are observed, which is consistent with a concerted mechanism.
From a molecular orbital perspective, the formation of new bonds at phosphorus occurs through the interaction of the antibonding HOMO of the diradicaloid with the antibonding LUMO of the reacting partner or the interaction of the bonding LUMO of the diradicaloid with the bonding HOMO of the reacting partner, both of which are symmetry-allowed.
Interestingly, H2 addition is reversible; below 50 °C, H2 addition is observed, and above 60 °C, H2 release occurs to regenerate the original diradicaloid species.
Diradicaloids can also react as nucleophiles or electrophiles from their zwitterionic resonance forms. For example, [P(μ-NTer)2]2 has been shown to react with both Lewis basic N-heterocyclic carbenes as well as Lewis acidic gold(I) chloride (Figure 17).
Open-shell reactivity
For example, the phosphorus-centered diradicaloid [P(μ-NTer)2]2 can undergo stepwise radical addition reactions with alkyl bromides (Figure 18). The trans-addition products were exclusively formed, which is consistent with a stepwise radical abstraction followed by radical recombination mechanism.
Applications
Hetero-cyclopentane-1,3-diyls have been shown to display molecular switching behavior; this property relies on the ability to use external stimuli to switch a molecule between two different stable states, thereby allowing for easy modulation of special reactivity and/or other properties. Diradicaloids can serve as molecular switches if certain external stimuli can reversibly toggle between the planar isomer, which displays diradical character and corresponding reactivity, and the bicyclic housane isomer, which is a closed shell species.
For example, the concept of switchable diradicals was demonstrated using the hetero-cyclopentane-1,3-diyl with phosphorus-phosphorus centered radicals (Figure 19). Upon exposure to red light, the planar five-membered ring diradical isomerizes to the bicyclic housane species. After irradiation, the thermally induced reverse reaction occurs, breaking the transannular bond to regenerate the planar diradicaloid species. Thus, the activation chemistry of the diradical can be switched "off" via irradiation and can be switched back "on" via stopping irradiation. This switching could be repeated several times without degradation of the diradicaloid.
References
Molecular machines
Radicals | Diradicaloid | [
"Physics",
"Chemistry",
"Materials_science",
"Technology"
] | 4,647 | [
"Physical systems",
"Nanotechnology",
"Machines",
"Molecular machines"
] |
78,590,907 | https://en.wikipedia.org/wiki/Tribenzylamine | Tribenzylamine is an organic compound with the formula . It is a symmetrical tertiary amine. It is of some historic interest as one of the first compounds produced by the Leuckart reaction.
The compound is a common target in the development of new synthetic methods, e.g. from benzyl alcohol.
References
Amines
Benzyl compounds | Tribenzylamine | [
"Chemistry"
] | 71 | [
"Amines",
"Bases (chemistry)",
"Functional groups"
] |
78,591,075 | https://en.wikipedia.org/wiki/Split%20Fiction | Split Fiction is an upcoming action-adventure video game developed by Hazelight Studios and published by Electronic Arts. As a cooperative multiplayer-only game, Split Fiction is set to be released for Windows, PlayStation 5 and Xbox Series X and Series S in March 2025.
Gameplay
As with Hazelight's previous game, It Takes Two, Split Fiction was specifically designed for split screen cooperative multiplayer, which means that it must be played with another player through either local or online play. In the game, players assume control of either Zoe or Mio, two authors who both become trapped inside their own stories. The two strangers must work together to escape and overcome numerous challenges along the way, as Mio's science fiction story interweaves with Zoe's fantasy story, putting both characters in grave dangers. The game is an action-adventure video game played from a third-person perspective, requiring players to complete platforming challenges and occasionally combating against hostile enemies. Each stage is often accompanied with a unique but one-off gameplay mechanic. For instance, the two may be commanding dragons in one stage, while wielding a laser sword in another stage. The ability for both characters within each stage is also different, meaning that the two must collaborate with each other and utilize the respective abilities of their playable characters in order to progress. There are also side stories in each stage, with each also featuring an accompanying gameplay mechanic.
Development
Development of the game started following the release of It Takes Two (2021). A team of 80 people built the game using Unreal Engine 5. The two characters are named after Fares' two daughters, and Fares compared the game's narrative to that of a "buddy movie" as the two characters started as complete strangers who must slowly bond with each other in order to survive. Fares wrote that one of the biggest challenges developing a game with diverse gameplay mechanics was to ensure that each mechanic was fully polished. While a gameplay sequence utilizing a certain gameplay mechanic may only last for several minutes, the team had to work on them for months to ensure its controls were sufficiently intuitive.
Split Fiction was announced by Hazelight Studios and its game director Josef Fares at The Game Awards 2024. The game is currently set to be released for Windows, PlayStation 5 and Xbox Series X and Series S on March 6, 2025. As with Hazelight's previous games, it will utilize a "Friend’s Pass" system, in which owner of the game can invite a friend to play together for free. It will also support cross-platform play at launch. As with Hazelight's previous games, Split Fiction will be published under Electronic Arts' EA Originals label.
References
External links
Asymmetrical multiplayer video games
Video games developed in Sweden
Hazelight Studios games
Electronic Arts games
Windows games
PlayStation 5 games
Xbox Series X and Series S games
Cooperative video games
Video games featuring female protagonists
Fantasy video games
Science fiction video games
Split-screen multiplayer games
Action-adventure games
Platformers
Upcoming video games scheduled for 2025
Unreal Engine 5 games | Split Fiction | [
"Physics"
] | 611 | [
"Asymmetrical multiplayer video games",
"Symmetry",
"Asymmetry"
] |
78,591,596 | https://en.wikipedia.org/wiki/Automated%20medical%20scribe | Automated medical scribes (also called artificial intelligence scribes, AI scribes, digital scribes, virtual scribes, ambient AI scribes, AI documentation assistants, and digital/virtual/smart clinical assistants) are tools for transcribing medical speech, such as patient consultations and dictated medical notes. Many also produce summaries of consultations. Automated medical scribes based on Large Language Models (LLMs, commonly called "AI", short for "artificial intelligence") increased drastically in popularity in 2024. There are privacy and antitrust concerns. Accuracy concerns also exist, and intensify in situations in which tools try to go beyond transcribing and summarizing, and are asked to format information by its meaning, since LLMs do not deal well with meaning (see weak artificial intelligence). Medics using these scribes are generally expected to understand the ethical and legal considerations, and supervise the outputs.
The privacy protections of automated medical scribes vary widely. While it is possible to do all the transcription and summarizing locally, with no connection to the internet, most closed-source providers require that data be sent to their own servers over the internet, processed there, and the results sent back (as with digital voice assistants). Some retailers say their tools use zero-knowledge encryption (meaning that the service provider can't access the data). Others explicitly say that they use patient data to train their AIs, or rent or resell it to third parties; the nature of privacy protections used in such situations is unclear, and they are likely not to be fully effective.
Most providers have not published any safety or utility data in academic journals, and are not responsive to requests from medical researchers studying their products.
Privacy
Some providers unclear about what happens to user data. Some may sell data to third parties. Some explicitly send user data to for-profit tech companies for secondary purposes, which may not be specified. Some require users to sign consents to such reuse of their data. Some ingest user data to train the software, promising to anonymize it; however, deanonymization may be possible (that is, it may become obvious who the patient is). It is intrinsically impossible to prevent an LLM from correlating its inputs; they work by finding similar patterns across very large data sets. Some information on the patient will be known from other sources (for instance, information that they were injured in an incident on a certain day might be available from the news media; information that they attended specific appointment locations at specific times is probably available to their cellphone provider/apps/data brokers; information about when they had a baby is probably implied by their online shopping records; and they might mention lifestyle changes to their doctor and on a forum or blog). The software may correlate such information with the "anonymized" clinical consultation record, and, asked about the named patient, provide information which they only told their doctor privately. Because a patient's record is all about the same patient, it is all unavoidably linked; in very many cases, medical histories are intrinsically identifiable. Depending on how common a condition and what other data is available, K-anonymity may be useless. Differential privacy could theoretically preserve privacy.
Data broker companies like Google, Amazon, and Microsoft have produced or bought up medical scribes, some of which use user data for secondary purposes, which has led to antitrust concerns. Transfer of patient records for AI training has, in the past, prompted legal action.
Open-source programs typically do all the transcription locally, on the doctor's own computer. Open-source software is widely used in healthcare, with some national public healthcare bodies holding hack days.
Encryption
Multifactor authentication for access to the data is expected practice.
Typically, Diffie–Hellman key exchange is used for encryption; this is the standard method commonly used for things like online banking. This encryption is expensive but not impossible to break; it is not generally considered safe against eavesdroppers with the resources of a nation-state.
If content is encrypted between the client and the service provider's remote server (transport cryptography), then the server has an unencrypted copy. This is necessary if the data is used by the service provider (for instance, to train the software). Zero-knowledge encryption implies that the only unencrypted copy is at the client, and the server cannot decrypt the data any more easily than a monster-in-the-middle attacker.
Platforms
Scribes may operate on desktops, laptop, or mobile computers, under a variety of operating systems. These vary in their risks; for instance, mobiles can be lost. The underlying mobile or desktop operating systems are also part of the trusted computing base, and if they are not secure, the software relying on them cannot be secure either.
Confabulation, omissions, and other errors
Like other LLMs, medical-scribe LLMs are prone to confabulation, where they make up content based on statistically associations between their training data and the transcription audio. LLMs do not distinguish between trying to transcribe the audio and guessing what words will come next, but perform both processes mixed together. They are especially likely to take short silences or non-speech noises and invent some sort of speech to transcribe them as.
LLM medical scribes have been known to confabulate racist and otherwise prejudiced content; this is partly because the training datasets of many LLMs contain pseudoscientific texts about medical racism. They may misgender patients. A survey found that most doctors preferred, in principle, that scribes be trained on data reviewed by medical subject experts. Relevant, accurate training data increases the probability of an accurate transcription, but does not guarantee accuracy. Software trained on thousands of real clinical conversations generated transcripts with lower word error rates. Software trained on manually-transcribed training data did better than software trained with automatically transcribed training data (such as YouTube captions).
Autoscribes omit parts of the conversation classes as irrelevant. The may wrongly classify pertinent information as irrelevant and omit it. They may also confuse historic and current symptoms, or otherwise misclassify information. They may also simply wrongly transcribe the speech, writing something incorrect instead. If clinicians do not carefully check the recording, such mistakes could make their way into their medical records and cause patient harms.
Patient consent
Professional organizations generally require that scribes be used only with patient consent; some bodies may require written consent. Medics must also abide by local surveillance laws, which may criminalize recording private conversations without consent. Full information on how data is encrypted, transmitted, stored, and destroyed should be provided. In some jurisdictions, it is illegal to transmit the data to any country without equivalent privacy laws, or process or store the data there; vendors who cannot guarantee that their products won't illegally send data abroad cannot be legally used.
Some vendors collect data for reuse or resale. Medical professionals are generally considered to have a duty to review the terms and conditions of the user agreement and identify such data reuse. General practices are generally required to provide information on secondary uses to patients, allow them to opt out of secondary uses, and obtain consent for each specific secondary use. Data must only be used for agreed-upon purposes.
Technology and market
The medical scribe market is, , highly competitive, with over 50 products on the market. Many of these products are just proprietary wrappers around the same LLM backends, including backends whose designers have warned they are not to be used for critical applications like medicine. Some vendors market scribes specialized to specific branches of medicine (though most target general practitioners, who make up about a third of doctors). Increasingly, vendors market their products as more than scribes, claiming that they are intelligent assistants and co-pilots to doctors. These broader uses raise more accuracy concerns. Extracting information from the conversation to autopopulate a form, for instance, may be problematic, with symptoms incorrectly auto-labelled as "absent" even if they were repeatedly discussed. Models failed to extract many indirect descriptions of symptoms, like a patient saying they could only sleep for four hours (instead of using the word "insomnia").
LLMs are not trained to produce facts, but things which look like facts. The use of templates and rules can make them more reliable at extracting semantic information, but "confabulations" or "hallucinations" (convincing but wrong output) are an intrinsic part of the technology.
Pricing
With the exception of fully open-source programs, which are free, medical scribe computer programs are rented rather than sold ("software as a service"). Monthly fees vary from mid-two figures to four figures, in US dollars. Some companies run on a freemium model, where a certain number of transcriptions per month are free.
Scribes that integrate into Electronic Health Records, removing the need for copy-pasting, typically cost more.
Fully open-source scribes provide the software for free. The user can install it on hardware of their choice, or pay to have it installed. Some open-source scribes can be installed on the local device (that is, the one recording the audio) or on a local server (for instance, one serving a single clinic). They can typically be set not to send any information externally, and can indeed be used with no internet connection.
See also
Medical scribe
Large Language Model
AI hallucinations
List of open-source health software
References
Medical technology
Artificial intelligence | Automated medical scribe | [
"Biology"
] | 1,984 | [
"Medical technology"
] |
78,591,894 | https://en.wikipedia.org/wiki/Organomagnesium%20chemistry | Organomagnesium chemistry, a subfield of organometallic compounds, refers to the study of magnesium compounds that contains Mg-C bonds. Magnesium is the second element in group 2 (alkaline earth metals), and the ionic radius of Mg2+ is 86 pm, which is larger than Be2+ (59 pm) and smaller than the heavier alkaline earth metal dications (Ca2+ 114 pm, Sr2+ 132 pm, Ba2+ 149 pm), in accordance with periodic trends. Magnesium is less covalent compared to beryllium, and the radius is not large enough for accommodating large number of ligands compared to calcium, strontium and barium. Thus, organomagnesium compounds exhibit unique structure and reactivity in group 2.
The most important type of organomagnesium compound is the Grignard reagents, which are widely used in different fields of synthetic chemistry, especially in organic synthesis, for Grignard reagents serves as a robust source of carbanion. Although most other directions in organomagnesium chemistry are mainly limited to research interest, some areas, such as their application in catalysis and materials, are fast developing. Although most characterized Mg(I) and Mg(0) compounds do not contain Mg-C bonds, which means they cannot be rigorously categorized as organomagnesium compounds, they will be briefly discussed at the end of this page because of their great importance.
Carbon as anionic σ-ligand
Grignard reagents (RMgX)
Discovered by Victor Grignard at the university of in 1900, compounds with empirical formula RMgX (R = carbanion, X = Cl, Br, I) are known as Grignard reagents, which are widely used in organic synthesis and ligand preparation. Grignard reagents are a common source of carbanion, which can be used to perform nucleophilic addition, substitution, transmetalation, and metal-halogen exchange reactions. The first crystal structure of Grignard reagents was reported by Guggenberger and Rundle in 1964, from a crystalline EtMgBr(THF)2 (Et = ethyl, THF = tetrahydrofuran). The Mg-C bond length was found to be 2.15(2) Å, which is about the sum of covalent radii of magnesium (141(7) pm) and carbon (76(1) pm at sp3 hybridization).
Although Grignard reagents were discovered and commonly used in 1900s, the corresponding fluoride RMgF was not synthesized until 1970, plausibly because of the difficulty in breaking the strong C-F bond. In 1920 Swarts reported the reduction of amyl fluoride to the corresponding hydrocarbon with activated magnesium, while no intermediates were separated. Alkylmagnesium fluoride was first prepared by Ashly and co-workers in 1970, using metal magnesium and catalytic iodine in refluxing tetrahydrofuran or 1,2-dimethoxyethane from the corresponding alkyl fluoride.
Grignard reagents forms dimers in solutions, and the R and X groups are exchanged between magnesium centers, enabling the Schlenk equilibrium between RMgX and MgR2 and MgX2. Recent ab initio molecular dynamics computations have shown that the formation of such dimers is crucial for explaining the reactivity of Grignard reagents.
Magnesium dihydrocarbyl and other hydrocarbyl magnesium
Dialkylmagnesium is another convenient precursor of magnesium complexes, which is useful when halides are unwanted. Dialkylmagnesium is usually prepared from Grignard reagents, via precipitation of magnesium halide. Solid state dialkylmagnesium forms one-dimensional chains via Mg-C-Mg 3c-2e bonds, and the Mg-C bond length is 2.24(3) Å in dimethylmagnesium (Me2Mg)n, which is about 10 pm longer than the terminal alkyl-Mg bonds (e.g. 2.15(2) Å in EtMgBr(THF)2). Molecular oligomer of dialkylmagnesium with terminal ligands were also synthesized with similar Mg-C bonding scheme. With large steric hindrance, diaryl magnesium [(2,6-Et2C6H3)2Mg] was found to be a molecular dimer with bridging aryl groups, and the bridging Mg-C distances range between 2.243(7) to 2.296(7) Å. Similar bridging alkynyl groups were found in [(Me3Si)2NMg(C≡CR)(THF)]2 (R = Ph, SiMe3) with the bridging Mg-C distance ranging from 2.189(4) to 2.283(4) Å.
By applying synergistic effect of magnesium and another alkaline metal, deprotonation of hydrocarbon derivatives has become another facile method to achieve the corresponding magnesium complexes. For example, in 2001 Mulvey achieved tetradeprotonation of ferrocene trapped in an amide cationic ring with four magnesium and four sodium, [(iPr2N)8Na4Mg4{Fe(C5H3)2}], from free ferrocene and [Na(iPr2N)2Mg(nBu)].
Carbon as neutral σ-ligand
Carbonyl complexes
Unlike beryllium, calcium, strontium, and barium, no homoleptic carbonyl complex of magnesium has been found, probably because it lacks available (n-1)d orbitals, and it has low covalency. However, [Mg(O3)2(CO)2] which contains ozonide anion (O3−) was identified when condensing atomic magnesium, oxygen and carbon monoxide in solid argon matrix. The compound shows increased C-O stretching frequency at 2188.9 cm−1, compared to free carbon monoxide (2143 cm−1), indicating little back-bonding from magnesium to the carbonyl.
N-heterocyclic carbene complexes
The first characterized N-heterocyclic carbene (NHC) complex of magnesium, [(IMes)MgEt2]2 were synthesized in 1993 by Arduengo and co-workers, by simply mixing the stable carbene with diethylmagnesium. In [(IMes)MgEt2]2 the Mg-C(IMes) bond length was found to be 2.279(3) Å, which is significantly longer than the terminal Mg-C(Et) bond of 2.133(4) Å.
In 1995 Arduengo and co-workers characterized NHC adduct of MgCp*2 (Cp* = pentamethylcyclopentadienyl), which features one η5- and one η3-Cp* ligands. NHCs with side arms were also explored. The amido NHC complex of magnesium was synthesized by Arnold and colleagues in 2004, and the magnesium complex using NHC with phenol arms were synthesized and characterized by Zhang and Kawaguchi in 2006.
Since NHCs are better σ donors than ethers like THF, it provides a scaffold for cationic molecular magnesium complexes, for it is categorized as neutral L-type ligand. In 2019, Dagorne and co-workers reported the first cationic alkyl magnesium supported by NHC ligand, [LMgMe(THF)2]+ BPh4− (L = IMes, IPr). The synthesis proceeds through an interesting dimeric intermediate with two uncommon μ2-Me bridges. In [(IPr)MgMe(THF)2]+, the Mg-C(IPr) distance was found to be 2.2224(13) Å, which is slightly shorter than the distance in neutral NHC complexes.
Notably, Gilliard and co-workers reported the equilibrium between L2MgMeBr and [L3MgMe]+Br− (L = 1,3,4,5-tetramethylimidazol-2-ylidene) in d5-bromobenzene, showing the substitution is facile despite its being endothermic.
Carbon as π-ligand
Allyl complexes
Allyl Grignard reagents exhibit high reactivity and special selectivity compared to alkyl ones. X-ray determination of single crystal structure and NMR spectroscopy both suggest that the allyl groups favor an η1- instead of η3-coordination pattern. Density functional theory (DFT) computations have shown that the homoleptic complex (C3H5)2Mg adopts a C2-symmetric geometry with two η3-allyl groups, while coordination of THF molecules changed the allyl groups to η1.
Allyl groups can also serve as bridging ligands. In 2001, Balley and co-workers reported a magnesium complex {(Dipp-tBuNacNac)Mg(C3H5)}6 (Dipp-tBuNacnac = [HC{C(tBu)NDipp}2]−) featuring six μ-η1:η1 allyl ligands. Bridging μ-η1:η2 allyl ligands were also identified in a dimeric silyl allyl magnesium complex.
Cylopentadienyl complexes
Dicyclopentadienyl (Cp) magnesium or magnesocene (Cp2Mg) was first characterized in 1954 by Wilkinson and Cotton, and later crystal structure analysis shows that it features a 5-fold symmetry with two η5-cyclopentadienyl ligands. MgCp2 has an average Mg-C distance of 2.304(8) Å an average C-C distance of 1.39(2) Å, which is in agreement with a later gas-phase diffraction study. For comparison, in ferrocene the Fe-C distance is 2.04(1) Å and the C-C distance is 1.40(2) Å. Magnesocene derivatives generally adopt the ideal structures with staggered parallel Cp rings, though introducing large steric hindrance may distort the geometry, such as [{1,2,4-(Me3Si)3C5H2}2Mg] which has slightly bent sandwich structure.
25Mg-NMR spectroscopy suggested the Mg-Cp interaction has significant covalent character. However, because of lacking (n-1)d orbitals and back bonding, the Mg-Cp interaction is weak, enabling cyclopentadienyl magnesium complexes to serve as Cp− precursor. For example, in the following reaction Cp2Mg transfers two Cp− ligands to synthesize the [MnCp3]− anion:
Adding ligands to magnesocene derivatives gives bent Cp2MgL species, and the bonding modes of the cyclopentadiene are sensitive to the changes in the coordination environment. In [(C5Me4H)2MgL] (L = 1,3-di-iso-propyl-4,5-dimethylimidazol-2-ylidene), one of the C5Me4H ligand is slipped by 0.807 Å from the center, which makes difference of 0.69 Å between the shortest and the longest Mg-C distance on the ligand. Thus the complex can be described as [(η5-C5Me4H)(η3-C5Me4H)MgL].
Magnesium anthracene
Another important complex is the magnesium anthracene, which was first prepared by Ramsden in 1965, using a THF suspension of magnesium and anthracene. From the solution crystalline [(C14H10)Mg(THF)3] can be obtained, showing two relatively shorter Mg-C distances of 2.225(1) Å, on C9 and C10 of the anthracene. [(C14H10)Mg(THF)3] reacts like [C14H10]2- with the two negative charges mainly localized on C9 and C10, and can thus act as nucleophile to give functionalized anthracene or 9,10-dihydroanthracene derivatives. One of its recent application is to synthesize dibenzo-7λ3-phosphanorbornadiene (RPC14H10), which can be used as phosphinidene transfer reagent.
Magnesium complexes with neutral π ligands
One of the first magnesium-neutral C=C π interactions was identified in [(DBAP)2Mg]2 (DBAP = dibenzo[b,f]azepinate) by Harder and co-workers in 2017. The structure features one magnesium atom coordinated by four amino groups, and the other magnesium atom is weakly bound to three nitrogen atoms and three C=C π bonds. The Mg-olefin geometry is slightly asymmetric, with the shorter Mg-C distance range from 2.653(3) to 2.832(3) Å with an average of 2.740 Å, and the longer ones vary from 2.792(3) to 2.920(3) Å with an average of 2.848 Å. Previous research has also shown Mg-C distances of 2.559(6) to 2.638(3) Å in a tetrakis(2-aryloxy)ethylene system, but the shorter distance may be attributed to steric restriction.
In 2018, Harder and co-workers identified the first intramolecular Mg-π interaction in a cationic NacNac supported system, i.e., [(Dipp-NacNac)Mg(EtC≡CEt)][B(C6F5)4] and [(Dipp-NacNac)Mg(η3-C6H6)][B(C6F5)4] (Dipp-Nacnac = [HC{C(Me)NDipp}2]−). In the alkyne complex the two Mg-C distances are 2.480(2) and 2.399(2) Å, and in the arene complex the shortest Mg-C bond length is 2.520(2) Å. Later study showed that the binding mode of arenes is sensitive to substitution on the arene, e.g., [(Dipp-NacNac)Mg(η6-mesitylene)][B(C6F5)4] features a η6-like mesitylene with Mg-C distance ranging from 2.5325(17) to 2.6988(16) Å. The first intramolecular Mg-alkene binding was later identified in 2020. In [(Dipp-NacNac)Mg(H2C=CEt2)][B(C6F5)4], Mg is closer to the terminal methylene with Mg-C distance of 2.338(2) Å, and the longer Mg-C distance is 2.944(5) Å. DFT calculations and AIM analysis suggested that the Mg-alkene interaction is less covalent and should be mainly described as ion-induced dipole interactions, and the large asymmetry in the 2-ethylbutene complex should be attributed to charge distribution on the two sp2 carbon atoms.
Although [(C6H6)2Mg]2+ remains unknown, the isoelectronic boratabenzene complex has been synthesized by Herberich and co-workers in 2000. In the work [(C5H5BMe)2Mg] and [(3,5-Me2C5H3BNMe2)2Mg] were characterized, with [(C5H5BMe)2Mg] having average Mg-C distance of 2.403 Å (2.359(2) to 2.453(2) Å) and [(3,5-Me2C5H3BNMe2)2Mg] having average Mg-C distance of 2.391 Å (2.350(1) to 2.429(2) Å). The slightly longer Mg-C distance compared to Cp2Mg indicates a weaker donor ability of the boratabenzene, likely due to a more dispersed electron density among six instead of five atoms. Similar to Cp2Mg derivatives, adding ligands like bipyridine (bipy) makes one of the boratabenzene slipped to form [(η5-3,5-Me2C5H3BNMe2) (η1-3,5-Me2C5H3BNMe2)Mg(bipy)], while coordination of THF changes the ligand to N-donor in [(N-3,5-Me2C5H3BNMe2)2Mg(THF)2].
Applications
For the wide applications of Grignard reagents, please refer to the corresponding page.
The luminescence properties of magnesium compounds have been studied since the pioneering work by Chandrasekhar and co-workers in 2005, where a phosphorus-based tris-hydrazone complex of Mg(II) was synthesized and determined to have an intense fluorescence emission peak at 442 nm in dichloromethane solution.
In 2018, Roesky and co-workers developed a diamidophosphine ligand, with the ligated dimagnesium(II) compound having a fluorescence quantum yield of 34% in the solution. Munz and co-workers developed a pincer-like carbazole-mesoionic carbene ligand in 2021, delivering its magnesium complex a quantum yield of 14%. In 2022, Sen and colleagues reported two 2,2′-pyridylpyrrolide supported magnesium complexes, one mononuclear and one dinuclear, with quantum yield of 14% and 22%, respectively.
Catalytic systems for hydroboration reactions based on magnesium complexes have been investigated, with the pioneering work by Hill in 2012, where a Nacnac supported magnesium(II) hydride dimer was used to catalyze the hydroboration of ketones. Magnesium complexes have also been found to catalyze nucleophilic cyclization reactions.
Low-oxidation state magnesium complexes
The first molecular Mg(I) compound, which contains a Mg-Mg bond, was synthesized by Jones, Stasch, and co-workers in 2007, from potassium metal reduction of Nacnac or priso ligand supported magnesium halide. In the [(Dipp-Nacnac)Mg]2 the Mg-Mg distance is 2.8457(8) Å, and in the [(Dipp-NMe2Priso)Mg]2 (Dipp-NMe2Priso = [Me2NC(NDipp)2]−) the Mg-Mg distance is 2.8508(12) Å, both approximately equal to twice of the covalent radius of magnesium. In 2016, Jones and co-workers reported Mg(I) compounds with super bulky amido ligands, delivering a two-coordinate Mg(I). In [{2,6-(Ph2CH)2-4-iPr-C6H2}Mg]2, the Mg-Mg distance of 2.8223(11) Å is significantly shorter than the N,N’-chelated Mg(I) dimers.
The first Mg(0) compound was reported in 2021 by Harder and co-workers, by reducing a similar Nacnac chelated in a harsher condition using newly prepared Na/NaCl.
In 2010, Platts and co-workers characterized a non-nuclear attractor in the Mg-Mg bond of [(Dipp-Nacnac)Mg]2 from experimental electron density, which suggest the specialty of the Mg-Mg bond.
Mg(I) compounds have been proven to be useful reductants in synthetic chemistry. They have been found to be doing reversible addition to C=C double bonds, C-F bond activation, CO reduction, defluorination of PTFE, and reduction of OCP−.
See also
Magnesium compounds
Main group organometallic chemistry
Group 2 organometallic chemistry
Organoberyllium chemistry
Organocalcium chemistry
Alkaline earth octacarbonyl complex
Organozinc chemistry
References
Organomagnesium compounds | Organomagnesium chemistry | [
"Chemistry"
] | 4,377 | [
"Organomagnesium compounds",
"Reagents for organic chemistry"
] |
78,592,881 | https://en.wikipedia.org/wiki/Lipophorin | Lipophorin is a lipid-carrying protein of insects, first identified in 1981, and is the major lipoprotein in the plasma of insects. Lipophorin has been identified in all insect species, in every life stage. Recently, additional nomenclature has been introduced to designate specific lipophorin subspecies that differ in lipid and/or apoprotein content. The concentration of lipophorin subspecies (HDLp and LDLp) changes can be considered to reflect the physiological state of the organism with respect to lipid metabolism. The versatility of this particle concerning its lipid binding capacity may be unparalleled in nature.
Biosynthesis
Lipophorins are synthesized in fat body and secreted into hemolymph. In larval Manduca sexta, nascent lipophorin particles were synthesized from fat body cells and they associate with phospholipid to form a nascent Very High Density Lipophorin (VHDLp), which is essentially devoid of diacylglycerol. The VHDLp is then secreted into the hemolymph, where it later interacts with the mid gut to load DAG, which is derived from dietary lipids. The maturation of lipophorin into circulating High Density Lipophorin (HDLp) results in a density shift from 1.26 to 1.15 g/ml with no change in apoprotein content. The lipophorin contains two structural apolipoproteins, derived from ApoLp-II/I precursor by enzymatic cleavage (furin). Furin is a member of the proprotein convertase family of subtilisin like serine endoproteases that is mainly active in the trans-Golgi network. The favored consensus substrate sequence for furin, R-X-K/R-R, is present in all precursor sequences characterized to date. In agreement with the activity of furin, Locusta migratoria ApoLp II/I precursor appears to be cleaved C-terminal of its furin substrate sequence, RQKR, as indicated by the N-terminal sequence of ApoLp I.
Structure
Lipophorins are large, amphipathic complexes composed of proteins and lipids. They are structurally similar to vertebrate lipoproteins, like low-density lipoproteins (LDLp) and high-density lipoproteins (HDLp). The core of a lipophorin particle typically consists of nonpolar lipids, such as diacylglycerols and hydrocarbons, surrounded by a layer of phospholipids, cholesterol, and apolipoproteins.
For HDLp, there is a remarkable abundance of a single lipoprotein particle in the hemolymph of insects. HDLp-reuse discrimination is one of the characteristics that strain it to be a reusable shuttle for the lipids within the target tissue. HDLp is largely a spherical particle about 450-600 kDa and has a density similar to that of a mammalian HDLp (~ 1.12 g/ml). This is usually containing DAG as its predominant lipid in addition to phospholipids, sterols, and hydrocarbons. The lipoprotein generally contains one copy of each of the two non-exchangeable apolipoproteins, viz. apolipophorin I (apoLp-I) and apolipophorin II (apoLp-II; weighing ~ 240 and ~ 80 kDa, respectively), derived from a single common precursor protein by post-translational cleavage. As a novel molecular characterization of the apolipophorin precursor, it has recently been revealed for a few insect species that the protein is arranged with apoLp-II at the N-terminal end and apoLp-I at C-terminal end (thus also termed as apoLp-II/I). At the N-terminus of apoLp-I, followed by the amino acid sequence RQKR, similar to the other apolipophorin precursors known to date, in locust apoLp-II/I (3359 aa residues). Therefore, it is likely that during the proteolytic processing of this precursor protein to generate apoLp-II and apoLp-I, dibasic processing endoproteases of the subtilisin family are involved.
Types
Lipophorin exists in three subspecies, each serving specialized functions in lipid transport within insects. The primary forms are high-density lipophorin (HDLp) and low-density lipophorin (LDLp). HDLp acts as the principal circulating lipoprotein, shuttling lipids such as diacylglycerol, phospholipids and sterols throughout the hemolymph. LDLp is derived from HDLp during periods of high lipid transport demand, such as flight or vitellogenesis, as it becomes enriched with diacylglycerol. Additionally, very high-density lipophorin (VHDLp), found in some species, primarily carries hydrocarbons. These subspecies work together dynamically, adapting to the insect’s metabolic and developmental needs.
Function
Lipophorin is an incredible lipid-transporting protein studied in insects. Lipophorin is an important protein whose lipid metabolism and transfer are critical in general. Lipophorin is the main carrier of different lipids, such as diacylglycerol (DAG), hydrocarbons, phospholipids, and sterols, into insect hemolymph (blood). Invertebrate lipophorin carries these molecules from storage organs such as body fat to energy demanding or structural lipid – dependent tissues in the organism. A unique feature of lipophorin is its storage effectiveness, as it is able to shuttle lipids multiple times without being destroyed in the process. Thus, it is a very useful means of lipid transport over a long period of time.
While flying, diacylglycerol from lipophorin is being carried to the flight muscles, where it gets converted into energy through β-oxidation. Lipophorin is also necessary for cholesterol transport and performs functions similar to HDL in humans, such as membrane synthesis and hormone production. Interaction with such other proteins as lipid transfer particles (LTP) provides lipophorin with dynamic flexibility in transferring and uptake lipids. Combined with the metabolic state of the insect, the idea of adaptability within the lipophorin is further strengthening its versatility and performance level.
During vitellogenesis, lipophorin transports lipids like diacylglycerol (DAG) from the fat body to the ovaries, where they are used for yolk formation in developing oocytes. Acting as a reusable shuttle, it interacts with ovarian receptors to deliver lipids essential for vitellogenin synthesis and lipid-rich yolk deposition. This efficient lipid transport is crucial for oocyte maturation and successful embryogenesis. Lipophorin was present in nurse cells and follicle cells and marginally with perioocyte space in immature ovariole. In the mature ovariole, nurse cell was narcotized and lipophorin appeared in follicular cell. Its illustrate that lipids and proteins gradually accumulated in the developing ovary. But lipophorin was endocytic uptake in immature ovariole, after the maturation uptake halted.
Lipophorin transports the hydrophobic molecule from origin to destination in time specific manner. All hydrocarbons bound in a lipid binding pocket, most of these sharing the same binding sites for hydrophobic interaction and hydrogen bonding. Overall findings elucidated that lipophorin associated with different hydrocarbons by hydrogen bonds and hydrophobic interactions, and each of the hydrocarbon having various functional roles.
References
Biochemistry | Lipophorin | [
"Chemistry",
"Biology"
] | 1,691 | [
"Biochemistry",
"nan"
] |
78,594,273 | https://en.wikipedia.org/wiki/Mortgage%20button | The "mortgage button" or "amity button" was a small ornamental inlay often featured on newel posts of a main staircase in the 19th and early 20th centuries, particularly in American and European homes. It was used to hide joinery.
The name comes from the historical misconception that they represented a homeowner who had paid off their mortgage. According to tradition, the homeowner would arrange to have a button made of ivory set onto the newel post when the house was paid off. Another version is that a scrimshaw maker would engrave the date the loan was paid off onto a piece of ivory, which was inserted the newel.
One popular myth was that the decorative cap was concealing a deed to the house, or a mortgage document, which had been rolled up and hidden inside the newel post. According to writer Mary Miley Theobald, no such documents have ever been found, although house plans were found inside the newel post on one occasion.
Others have suggested that the ivory button on the newel post was a symbol of cooperation or brotherly love.
References
Stairways
Architectural elements
Stairs | Mortgage button | [
"Technology",
"Engineering"
] | 232 | [
"Building engineering",
"Architectural elements",
"Components",
"Architecture"
] |
78,594,414 | https://en.wikipedia.org/wiki/Zirconium%20silicon%20sulfide | Zirconium silicon sulfide (ZrSiS) is a crystalline layered Dirac semi-metal compound of zirconium, silicon and sulfur. Its crystals are made from planes of five single-atom layers of each element in the order S-Zr-Si-Zr-S, with the single element planes connected to their neighbors by van der Waals forces.
Semi-Dirac fermions were first observed within ZrSiS.
References
Zirconium compounds
Silicon compounds
Sulfides
Semimetals | Zirconium silicon sulfide | [
"Physics",
"Materials_science",
"Engineering"
] | 109 | [
"Materials science stubs",
"Materials science",
"Materials",
"Condensed matter physics",
"Semimetals",
"Matter"
] |
78,594,739 | https://en.wikipedia.org/wiki/Algebraic%20closure%20%28convex%20analysis%29 | Algebraic closure of a subset of a vector space is the set of all points that are linearly accessible from . It is denoted by or .
A point is said to be linearly accessible from a subset if there exists some such that the line segment is contained in .
Necessarily, (the last inclusion holds when X is equipped by any vector topology, Hausdorff or not).
The set A is algebraically closed if .
The set is the algebraic boundary of A in X.
Examples
The set of rational numbers is algebraically closed but is not algebraically open
If then
. In particular, the algebraic closure need not be algebraically closed.
Here, .
However, for every finite-dimensional convex set A.
Moreover, a convex set is algebraically closed if and only if its complement is algebraically open.
See also
Algebraic interior
References
Bibliography
Convex analysis
Functional analysis
Mathematical analysis
Topology | Algebraic closure (convex analysis) | [
"Physics",
"Mathematics"
] | 177 | [
"Mathematical analysis",
"Functions and mappings",
"Functional analysis",
"Mathematical objects",
"Topology",
"Space",
"Mathematical relations",
"Geometry",
"Spacetime"
] |
78,596,008 | https://en.wikipedia.org/wiki/NGC%202566 | NGC2566 is a barred spiral galaxy in the constellation of Puppis. Its velocity with respect to the cosmic microwave background is 1898 ± 19km/s, which corresponds to a Hubble distance of . However, five non-redshift measurements give a much closer distance of . It was discovered by German-British astronomer William Herschel on 6 March 1785.
Morphology
Eskridge, Frogel, and Pogge published a paper in 2002 describing the morphology of 205 closely spaced spiral or lenticular galaxies. The observations were made in the H-band of the infrared and in the B-band (blue). Eskridge and colleagues described NGC 2566 as a:
PGC 80593 Group
NGC 2566 is a member of the PGC 80593 Group, which contains 16 galaxies. In addition to NGC 2566 and PGC 80593, the group includes UGCA 137, IC 2311, NGC 2559, PGC 23156, and 10 galaxies from the ESO catalogue.
Image gallery
See also
List of NGC objects (2001–3000)
References
External links
2566
023303
-04-20-008
495- G 003
UGCA objects
08166-2520
Puppis
17850306
Discoveries by William Herschel
Barred spiral galaxies | NGC 2566 | [
"Astronomy"
] | 266 | [
"Puppis",
"Constellations"
] |
78,597,479 | https://en.wikipedia.org/wiki/Purma | A purma is a type of early successional forest, or secondary forest, in the Amazon Basin.
In the Amazon, people convert forest to farms and plantations called chacras. If that farm should be abandoned, the local plants begin to recolonize the area. It is then called a purma.
References
HabitatsForestsForest ecologyReforestation | Purma | [
"Biology"
] | 78 | [
"Forests",
"Ecosystems"
] |
78,597,520 | https://en.wikipedia.org/wiki/Quasibodo | Quasibodo is a genus of free-living flagellate protist containing the single species Q. laughtonii. The species was described in 2000 from anoxic marine and freshwater sediments. The genus has not yet been placed in any family or higher taxon, and as of 2025 holds a classification of incertae sedis.
References
Flagellates
Taxa described in 2000 | Quasibodo | [
"Biology"
] | 79 | [
"Eukaryotes",
"Eukaryote stubs"
] |
78,598,437 | https://en.wikipedia.org/wiki/Richard%20C.%20Willson | Richard C. Willson is a professor of chemical and biomolecular engineering at the University of Houston noted for his work on the development of purification, detection, and measurement technologies for applications in pharmaceutical manufacturing, process control, and medical diagnostics.
Education
Willson received B.S. and M.S. degrees in chemical engineering from Caltech in 1981 and 1982, respectively. He moved to the Massachusetts Institute of Technology for his doctoral work, where he worked under Charles L. Cooley and Richard C. Reid and received his PhD in 1998.
Career
Willson joined the Department of Chemical Engineering (now the William A. Brookshire Department of Chemical & Biomolecular Engineering) at the University of Houston in 1988, where he is currently the Huffington-Woestemeyer Professor.
He has developed methods to detect viruses and other biothreats based on the materials underpinning reflective vests, glow-in-the-dark stars, and glow sticks. In 2024, he led a project on antibody measurement as part of a grant from the National Institute for Innovation in Manufacturing Biopharmaceuticals.
His most-cited research article established the technique of combinatorial screening for catalysts. Other highly-cited research articles report DNA aptamer binding to vascular endothelial growth factor and develop luminescent nanoparticles as reporters in a sensitive lateral flow assay.
He is a member of the editorial boards of Biotechnology Progress and PLOS One. He contributed episodes on chromatography and avocado seeds to Engines of Our Ingenuity.
Awards and recognition
1990 — NSF Presidential Young Investigator
1999 — Fellow of the American Institute for Medical and Biological Engineering
2001 — James M. van Lanen Distinguished Service Award from the ACS Biotechnology Division
2011 — Fellow of the American Association for the Advancement of Science
2014 — Fellow of the American Chemical Society
2014 — Fellow of the National Academy of Inventors
2015 — Pierce Award in Affinity Technology from the International Society for Molecular Recognition
2021 — Alan S. Michaels Award in Recovery of Biological Products from the ACS Biotechnology Division
References
Living people
Chemical engineers
Biomedical engineers
Fellows of the American Chemical Society
Fellows of the National Academy of Inventors
Fellows of the American Institute for Medical and Biological Engineering
Year of birth missing (living people)
University of Houston faculty
Place of birth missing (living people) | Richard C. Willson | [
"Chemistry",
"Engineering"
] | 475 | [
"Chemical engineering",
"Chemical engineers"
] |
78,598,745 | https://en.wikipedia.org/wiki/Neptune%20All%20Night | Neptune All Night was a 9-hour TV program providing live coverage of the Voyager 2 space probe's flyby of the planet Neptune. The show, produced by the Philadelphia-area PBS affiliate WHYY-TV, was broadcast between midnight and 9:00 AM EDT on August 25, 1989, as Voyager 2 passed within of the planet Neptune and within of Neptune's largest moon, Triton. Aired by nearly 100 PBS stations, the program was occasionally referred to as "Voyager All Night". David Othmer, the show's executive producer, favored "Beyond Uranus" as a working title, but was "voted down".
Program description
The show provided live coverage of black-and-white images transmitted from the spacecraft interspersed with color images which had been digitally composited from data previously transmitted by Voyager. Due to Voyager's 4.3 billion km ( billion mi) distance from the Earth, the images were subject to a four hour and six minute delay, with the signal relayed through tracking stations in Australia, Spain, and the Mojave Desert in California. The program's format included 20-minute segments with NASA and JPL scientists commenting on the most recent images alternating with 40 minutes of other material originating from the WHYY studio: a panel discussion with experts; commentary from science-fiction authors and well-known figures; analysis of Voyager's earlier encounters with Jupiter, Saturn, and Uranus; and "a frivolous look at space travel in movies and science-fiction literature". Viewers could call in with questions on a toll-free line, 1-800-FLY-OVER.
Panelists included Jack Horkheimer, Judith Moffett, and Jesco von Puttkamer with Sedge Thomson hosting the show. Other well-known people scheduled to appear included Ira Flatow, who would be conducting interviews from JPL; science writer Timothy Ferris; astronomer Carl Sagan; science fiction author Ray Bradbury; astronomer Clyde Tombaugh, who discovered the planet Pluto in 1930; and Apollo 9 crew member Rusty Schweickart.
Funding for the show included a $35,000 () grant from the Public Broadcasting Service. In 1989, real-time dissemination of scientific data was a rarity; the live program was designed to address this, in conjunction with daily press conferences the Voyager team gave around the time of the flyby. In a 2019 interview, Voyager project scientist Ed Stone said:
Reaction
Although commercial broadcasters, along with CNN on cable, had provided major reports in the week leading up to the flyby, Broadcasting described the noncommercial WHYY program as "the most dramatic coverage". C-SPAN also provided coverage. Kenneth R. Clark of the Chicago Tribune noted the coverage from commercial broadcasters, but said that "PBS's continuous coverage is by far the most ambitious". Astronomer Christian Ready wrote in his blog that his attention that night was distracted from his observational work on Villanova University's 15-inch telescope by a TV set he had brought into the observatory to watch "image after raw, grainy image appear on the screen revealing an alien world as seen by the spacecraft".
David Paquet, who worked for a PBS affiliate in Vermont, wrote in the White River Junction Herald that the program was "a bit in the style of a telethon". Paquet said that the Vermont PBS archives does not contain an intact copy of the complete program. He believes that no complete professional recording was ever made, although multiple partial recordings can be found on YouTube.
References
Voyager program
1989 American television series debuts
Neptune
American live television shows
1989 American television series endings | Neptune All Night | [
"Astronomy"
] | 741 | [
"Documentary television series about astronomy",
"Works about astronomy"
] |
78,598,971 | https://en.wikipedia.org/wiki/SDSS%20J1038%2B4849 | SDSS J1038+4849 is a galaxy cluster 4.5 billion light-years away in the constellation Ursa Major, famous for its appearance as a smiley face. The yellow eyes and white nose are distant galaxies, while the smile and border are caused by gravitational lensing.
References
Galaxy clusters
Ursa Major | SDSS J1038+4849 | [
"Astronomy"
] | 66 | [
"Galaxy clusters",
"Ursa Major",
"Astronomical objects",
"Constellations"
] |
78,599,483 | https://en.wikipedia.org/wiki/Edward%20A.%20Boyle | Edward A. Boyle is an American professor of marine geochemistry at the Massachusetts Institute of Technology’s (MIT) Center for Global Change Studies. Boyle’s research is primarily focused on the relationship between climate change and oceanic chemistry. Boyle was made a member of the National Academy of Sciences in 2008.
Education
Edward A. Boyle attended the University of California, San Diego, where he earned a bachelor’s degree in chemistry with highest honors in 1971. Boyle then attended the Woods Hole Oceanographic Institution(WHOI) and the Massachusetts Institute of Technology (MIT) through a joint program, earning a Ph.D. in oceanography in 1976. Boyle is currently a professor at MIT’s Center for Global Change Studies where he researches anthropogenic emissions and oceanic chemistry.
Research
Boyle’s research has primarily focused on marine chemistry and climatological studies with an emphasis on the relationship between trace metals present in the ocean and the atmospheric transport of anthropogenic emissions. Boyle’s work in studying how trace metals and their isotopes have led to the publication of several scientific papers on the subject. Boyle is also interested in the role the ocean has played in climate change over the last several thousand years and was the first scientist to observe predicted responses in deep ocean chemistry from the Younger Dryas period.
Anthropogenic lead emissions
Much of Boyle’s research has centered on the observation of lead isotopes and other trace metals in the ocean. Boyle has observed a perceptible rise in lead isotopes found in ocean and lake sediments from the 19th century onwards. In a March 2016 paper published in Environmental Pollution, Boyle and several other scientists observed increased lead isotope deposits in MacRitchie Reservoir in central Singapore dating from the late 19th and 20th centuries. Core samples of the sediments taken from the Reservoir show a sharp rise in background lead in sediment layers beginning in the late 19th century and peaking in the mid-20th century. Samples taken from nearby topsoil also support this observation. Boyle directly attributes these increased lead isotope deposits to the widespread use of leaded gasoline. Despite the relegation of leaded gasoline in North America, Europe, and South Asia, Boyle and his team have determined that the burning of coal as a source of energy has led to the release of lead isotopes and other metals into the atmosphere contributing to increased amounts of background lead pollution in soils and sediments.
Boyle has also conducted research in Greenland where he has studied ice cores in search of anthropogenic trace metals. He also studies the amounts and types of mineral dust found in river estuaries to observe essential iron in the ocean. He has also contributed to the study of how lead and other heavy metal pollutants affect marine chemistry.
Honors and awards
Boyle has been elected to the:
National Academy of Sciences
He has been made a fellow of:
American Association for the Advancement of Science, and
Fellow, American Geophysical Union
He has received numerous awards including:
Urey Medal from the European Association of Geosciences
Patterson Medal from the Geochemical Society, and the
A.G. Huntsman Award for Excellence in the Marine Sciences from the Bedford Institute of Oceanography
References
Year of birth missing (living people)
Living people
Geochemists
Massachusetts Institute of Technology faculty
University of California, San Diego alumni
Members of the United States National Academy of Sciences
Fellows of the American Association for the Advancement of Science | Edward A. Boyle | [
"Chemistry"
] | 679 | [
"Geochemists"
] |
78,601,046 | https://en.wikipedia.org/wiki/Tuncer%20Cebeci | Tuncer Cebeci (born August 25, 1934 – March 28, 2021) was a Turkish-American mechanical engineer and academic. He worked at Douglas Aircraft Company, and later he founded and chaired the Aerospace Engineering Department at California State University in Long Beach, USA. He authored books and scientific articles on fluid dynamics.
Early years and education
Tuncer Cebeci was born to Rabia and Ömer on August 25, 1934 in Turkey. He had a brother, Dinçer (1938–2004), who was a lawyer and racing horses owner. He was raised in Turkey, and graduated from Robert College in Istanbul with B.S. degrees in electrical and mechanical engineering. He then went to the United States, and attended Duke University in Durham, North Carolina, where he received an M.S. degree in mechanical engineering. In 1963, he married at New Hope Methodist Church in Winston-Salem, North Carolina to Sylvia Ann Holt (born 1941), whom he had met at the university two years prior. The next year, Cebeci received his doctoral degree in mechanical engineering from North Carolina State University in Raleigh.
Professional career
After completing his doctoral studies, Cebeci moved with wife and their newborn daughter to Long Beach, California to join Douglas Aircraft Company as a research scientist. In 1974, he was promoted to head of the department of aerodynamics research. He became the first distinguished professor in the mechanical engineering department of California State University (CSU) in Long Beach in 1977. In 1982, he became the company's first senior fellow. Cebeci founded the Department of Aerospace engineering at CSU, Long Beach, and became the chairman of the department in 1998.
Family and death
Cebeci and his wife Sylvia Ann undertook many worldwide travels. They raised two daughters, Rabia and Leyla, and a son, Bradley Omer, who became a lawyer. Rabia married to Philip Weiss. The eldest of their three children, Jordan Tate Weiss (1993–2011), died after a skateboarding accident. Cebeci lost his wife in 2012. Tuncer Cebeci died at age 86 in Los Angeles, California, United States on March 28, 2021.
Works
He authord 20 books and published over 300 technical journal articles. He worked on computational fluid dynamics. He is the co-developer of the Cebeci-Smith model for mathematical turbulence analysis.
Some of his books are:
Honors
1984 – "Fluid and Plasma Dynamics Award" from the American Institute of Aeronautics and Astronautics (AIAA),
1987 – "Distinguished Alumni Award" from the North Caroline State University,
1988 – "Presidential Science Award" from Turkey,
1993 – "Aerodynamics Award" from the AIAA,
1993 – "Distinguished Fellow Award" from McDonnell Douglas.
References
1934 births
2021 deaths
Robert College alumni
Turkish mechanical engineers
20th-century Turkish engineers
Duke University alumni
North Carolina State University alumni
Turkish emigrants to the United States
20th-century American engineers
Naturalized citizens of the United States
American mechanical engineers
McDonnell Douglas people
Engineers from Los Angeles
American aerospace engineers
American technology writers
Fluid dynamicists
Computational fluid dynamicists
20th-century American writers
California State University, Long Beach faculty
Academics from Los Angeles
American academics of Turkish descent
Death in Los Angeles | Tuncer Cebeci | [
"Chemistry"
] | 650 | [
"Fluid dynamicists",
"Fluid dynamics"
] |
78,601,151 | https://en.wikipedia.org/wiki/Kincardine%20floating%20offshore%20wind%20farm | The Kincardine floating offshore wind farm is located off the east coast of Scotland, about south-east of Aberdeen. It has an installed capacity of nearly 50 MW, and when commissioned in 2021 it was the world's largest wind farm with floating turbines.
It is a demonstration project that consists of six turbines, all mounted on semi-submersible platforms. The first turbine, a Vestas V80-2 MW, was installed in 2018. This was joined by five larger V164-9.5 MW turbines in 2021.
The project was developed by Kincardine Offshore Windfarm Ltd. (KOWL), initially comprising Pilot Offshore Renewables and Atkins, however this is now a joint venture between Flotation Energy and the Cobra Group.
Statkraft has a power purchase agreement to buy all of the power generated, estimated at over 200 GWh per year, equivalent to about 50,000 homes. This contract gives a guaranteed minimum price until 2029, reducing the financial risk of the project.
Although the project is named Kincardine, it is not located near Kincardine, Fife or Kincardineshire.
Technology
Each of the turbines is mounted on a triangular floating semi-submersible platform, the WindFloat® designed by Principle Power. These have three buoyant columns about high and apart. These are tethered to the seabed by cables, allowing them to be installed in much deeper waters than conventional (fixed) offshore wind turbines.
The wind turbine tower is mounted on one of the buoyant columns, as shown in the CAD rendering on the right.
Power from the wind farm is exported via two subsea cables, each rated at 33 kV, which were supplied by Prysmian Group.
History
Plans for the project were announced in 2014 by Pilot Offshore Renewables and Atkins, with the aim of starting construction in 2016 and generating power by 2018.
In March 2017, the Scottish Government approved plans for the Kincardine demonstration project. It was originally proposed to consist of eight turbines rated at 6 MW.
By November 2017, revised plans were announced to develop the project in two or more phases, in order to meet the Scottish Government deadline of October 2018 for eligibility for 3.5 Renewables Obligation Certificates (ROCs) for floating wind. An initial phase with a 2 MW turbine would be installed in 2018, followed by the remaining 48 MW in 2019 and 2020.
In 2016, the project was anticipated to cost around £250m, but by 2018 the costs had risen to around £500m.
The first turbine was assembled onto its foundation in the Port of Dundee, and on 16 August 2018 was towed out to the wind farm site by the Pacific Duchess and two tugs. The first power was exported on 18 September 2018, just meeting the ROC deadline. This turbine has been operating at the site since October 2018.
The floating foundations for the second phase were constructed in a fabrication yard in Ferrol, Spain. They were then towed to Rotterdam, where the diameter turbines with a tip height of were added. The first of the turbines was towed from Rotterdam to the site in December 2020, by the Boskalis anchor handling vessel Manta. Once on site, the turbines were connected to the pre-installed spread moorings.
By October 2021, all six turbines were commissioned and the project started commercial operation.
In July/August 2024, the generator of one of the turbines was replaced at sea, the first time any major component on has ever been replaced at sea. Previously, turbines had to be returned to port for any significant maintenance. A crane supplied by LiftOff, was assembled on the turbine nacelle and used to lift the generator then lower it onto the floating foundation, where it was then transferred to a offshore supply vessel. The new generator was installed using the reverse of this process.
References
Floating wind turbines
Offshore wind farms in the North Sea
Renewable energy in Scotland | Kincardine floating offshore wind farm | [
"Engineering"
] | 794 | [
"Floating wind turbines",
"Offshore engineering"
] |
78,601,263 | https://en.wikipedia.org/wiki/International%20Federation%20of%20Engineering%20Education%20Societies | The International Federation of Engineering Education Societies (IFEES) is a global network of engineering educators and allies. The missions of the federation are to enhance the effectiveness of member organizations and to contribute to the improvement of engineering education around the world. By identifying, sharing, and promoting effective engineering education processes, the federation contributes to efforts to assure a global supply of well-prepared engineering graduates.
History
The origins of the federation may be traced to an early conversation in 2005 at the Global Colloquium on Engineering Education in Australia. On October 9, 2006, representatives from 29 organizations and three industrial affiliates based in 18 countries formerly established IFEES during the American Society for Engineering Education's Global Conference in Rio de Janeiro, Brazil.
In 2016, to mark its tenth anniversary, the federation published a report outlining the history, current status, and future plans. In 2016, representatives from 47 organizations and eight industrial affiliates reaffirmed their commitment to the shared mission.
Initiatives
The federation organizes the annual World Engineering Education Forum (WEEF) in partnership with the Global Engineering Deans Council (GEDC) and a local host university. And the federation partners with allies to design and conduct surveys and publish new scholarship on engineering education in a global context.
Recognition
To recognize individuals who have made innovative and meritorious contributions with a significant impact on the advancement of engineering education, the IFEES selects an annual recipient of the Duncan Fraser Global Award for Excellence in Engineering Education. In 2015, the annual IFEES award became the IFEES Duncan Fraser Global Award for Excellence in Engineering Education. Fraser, who died on July 19, 2014, would have been IFEES’ 5th president.
Past winners, include:
<li>2024, Daniel B. Oerther, Missouri University of Science and Technology, USA
<li>2023, Uriel Cukierman, Universidad Tecnológica Nacional, Argentina
<li>2022, Pritpal Singh, Villanova University, USA
<li>2021, William Oakes, Purdue University, USA
<li>2020, Sheryl Sorby, University of Cincinnati, USA
<li>2018, Khairiyah Mohd Yusof, University of Technology Malaysia, Malaysia
<li>2016, Maria Larrondo Petrie, Florida Atlantic University, USA
<li>2015, Stephen Lu, University of Southern California, USA
<li>2014, Luiz Scavrda do Carmo, Pontifical Catholic University, Brazil
<li>2013, Anette Kolmos, Aalborg University, Denmark
<li>2012, Bopaya Bindanda, University of Pittsburgh, USA
<li>2011, Jack Lohmann, Georgia Institute of Technology, USA
<li>2010, Richard M. Felder, North Carolina State University, USA
References
External links
Official site
Engineering organizations
Professional associations based in the United States
Organizations established in 2006 | International Federation of Engineering Education Societies | [
"Engineering"
] | 577 | [
"nan"
] |
78,601,581 | https://en.wikipedia.org/wiki/PKS%201127-145 | PKS 1127-145 is a radio-loud quasar located in the constellation of Crater. This is a Gigahertz Peaked Spectrum object with a redshift of (z) 1.187, first discovered by astronomers in 1966. Its radio spectrum appears to be flat making it a flat-spectrum radio quasar, or an FRSQ in short.
Description
PKS 1127-145 displays blazar-like behavior. It is known to undergo a period of gamma ray activity, especially in December 2020 where its daily gamma ray flux reached a peak of (E > 100 MeV) of (1.6 ± 0.3) x 10−6 photons cm−2 s−1. Two flares were detected by Fermi-LAT in May and October 2022.
The radio structure of PKS 1127-145 is found complex. A radio image made by the Very Long Baseline Interferometry (VLBI) shows the object has two components, mainly a bright component and a much weaker component with same brightness temperatures of 1.3 x 1011 Kelvin. No extension is found in northwest direction. There is a presence of a compact core displaying strong increase of flux density with the outermost component being separated into several smaller regions enveloped completely by emission. A stationary feature is also seen located 4 mas from the core via a 22 GHz image taken by VLBI. Circular polarization has also been found in the quasar as well.
X-ray jet
An X-ray jet has been discovered in PKS 1127-145 by Chandra X-ray Observatory. With an estimated length of 300 kiloparsecs, this makes the longest one detected so far in any of the high redshift quasars. Advanced CCD Imaging Spectrometer also revealed a complex structure in the X-ray jet from the core with bright knots of different morphologies. Two of the knots showed changes in their profiles while the other knot is found fainter with presence of X-ray emission scattered over a large area.
A more in-depth analysis of the X-ray jet in PKS 1127-145 showed the inner jet of PKS 1127-145 located from the core is found to be extremely polarized and a parallel magnetic field towards the jet's axis. Upon reaching 18 arcseconds from the core, the jet suddenly bends slightly causing the re-brightening of radio emission. In additional, there is a 90° rotation of the magnetic field suggesting it might be compressed to the plane that is found perpendicular to the axis.
References
External links
PKS 1127-145
PKS 1127-145 on NASA/IPAC Database
Quasars
Crater (constellation)
2826758
Active galaxies
Blazars
Astronomical objects discovered in 1966 | PKS 1127-145 | [
"Astronomy"
] | 572 | [
"Crater (constellation)",
"Constellations"
] |
78,602,131 | https://en.wikipedia.org/wiki/Microplastic%20remediation | Microplastic remediation refers to environmental remediation techniques focused on the removal, treatment and containment of microplastics (small plastic particles) from environmental media such as soil, water, or sediment.
Microplastics can be removed using physical, chemical, or biological techniques.
Remediation of microplastics in air
Microplastic is a type of airborne particulates and is found to prevail in air.
Remediation of microplastics in water
Microplastics can be removed from water by filtration or absorption. Absorption devices include sponges made of cotton and squid bones.
Biochar filtration has been used in wastewater treatment plants.
Efforts to physically remove microplastics from the Great Pacific Garbage Patch have used nets and collection bags.
Remediaton of microplastics in soil
Microplastics are commonly found in soil. Techniques are under development to achieve reductions in soil microplastics via photodegradation, chemical extraction, or bioremediation.
See also
Environmental remediation
Microplastics and human health
Plastic pollution
References
Plastics and the environment
Pollution control technologies
Cleaning and the environment | Microplastic remediation | [
"Chemistry",
"Engineering"
] | 240 | [
"Pollution control technologies",
"Environmental engineering"
] |
68,415,663 | https://en.wikipedia.org/wiki/Plutonium%20selenide | Plutonium selenide is a binary inorganic compound of plutonium and selenium with the chemical formula PuSe. The compound forms black crystals and does not dissolve in water.
Synthesis
Reaction of diplutonium triselenide and plutonium trihydride:
2 {Pu2Se3} + 2 {PuH3} ->[\text{1600 °C}] 4 {PuSe} + 3 {H2}
Fusion of stoichiometric amounts of pure substances:
{Pu} + {Se} ->[\text{220–1000 °C}] PuSe
Properties
Plutonium selenide forms black crystals of a cubic system, space group Fmm, cell parameters a = 0.57934 nm, Z = 4, structure of the NaCl type.
With increasing pressure, two phase transitions occur: at 20 GPa into the trigonal system and at 35 GPa into the cubic system, a structure of the CsCl type.
Its magnetic susceptibility follows the Curie-Weiss law.
References
Inorganic compounds
Plutonium compounds
Selenides
Rock salt crystal structure | Plutonium selenide | [
"Chemistry"
] | 228 | [
"Inorganic compounds"
] |
68,417,050 | https://en.wikipedia.org/wiki/Interpersonal%20acceptance%E2%80%93rejection%20theory | Interpersonal acceptance–rejection theory (IPARTheory), was authored by Ronald P. Rohner at the University of Connecticut. IPARTheory is an evidence-based theory of socialization and lifespan development that attempts to describe, predict, and explain major consequences and correlates of interpersonal acceptance and rejection in multiple types of relationships worldwide. It was previously known as "parental acceptance–rejection theory" (PARTheory). IPARTheory has more than six decades of research behind it, therefore, in 2014, the name was changed to "IPARTheory" because the central postulates of the theory generalize to all important relationships throughout the lifespan.
Subtheories
IPARTheory consists of three interrelated subtheories. Together they address the causes, effects, and developmental correlates of interpersonal acceptance and rejection, as well as the global application of the theory. The three subtheories are personality subtheory, coping subtheory, and sociocultural systems subtheory and model.
Personality subtheory
Personality subtheory primarily addresses the pancultural outcomes of perceived interpersonal acceptance and rejection. Personality is defined as "an individual's more or less stable set of predispositions to respond (i.e. affective, cognitive, perceptual, and motivational dispositions) and actual modes of responding (i.e., observable behaviors) in various life situations or contexts." One major tenet of the theory states that all humans, regardless of racial, gender, cultural, or ethnic differences have a biologically based need for acceptance and positive responses from the important people, or significant others, in their lives. Significant others (attachment figures) are people that share a lasting emotional bond with and are uniquely important to a child or an adult, most often parents or romantic partners.
The nature of positive responses and acceptance behaviors from significant others may differ in specifics by culture, gender, and age. When children or adults do not receive the acceptance or positive response they need, they tend to perceive this as a form of interpersonal rejection and respond with a combination of 10 apparent pancultural dispositions. These dispositions include: anxiety, insecurity, hostility/aggression, dependency or defensive independence, negative self-esteem, negative self-adequacy, emotional unresponsiveness, emotional instability, negative worldview, and cognitive distortions.
Dependency, or "the internal, psychologically felt wish or yearning for emotional (as opposed to instrumental or task-oriented) support, care, comfort, attention, nurturance, and similar behaviors from significant others" is a very common response from people seeking acceptance following perceived rejection. People fall on a dependence continuum from independent to dependent. Where a person falls is primarily dependent on whether they perceive themselves to be accepted or rejected by significant others. Children and adults who perceive themselves to have received enough acceptance tend to show normal dependence, while children and others who do not receive enough acceptance or face rejection often develop defensive independence. Parental rejection or rejection from other significant others can result in impaired self-esteem, negative world-view, and emotional instability. In order to cope with these negative feelings and outcomes, people who feel rejected may develop defensive independence, in which a person either does not seek out or actively avoids emotional support and attachment to significant others despite still craving acceptance. Control is an additional variable influencing where someone falls on the dependency curve, children with immature dependence receive a great deal of acceptance but also intrusive parental control. This style of parenting is called "smother parenting" and children who experience it often struggle to develop age-appropriate social, emotional, and behavioral skills.
Coping subtheory
Coping subtheory seeks to understand why some children and adults do not appear to suffer the same ill effects of rejection that other rejected individuals face. The theory concentrates on affective copers, who have reasonably good mental and emotional health in the face of adversity, unlike instrumental copers, who may find success academically or professionally but still suffer with impaired mental and emotional health. The traits that make a good affective coper are still unclear, but coping subtheory uses the multivariate model of behavior to posit that the coping behavior of the individual is a function of interactions between the self (mental representations, biological, and personality characteristics of the individual), other (characteristics of the rejecting significant others, along with the form, frequency and severity of rejection), and context (other significant others, social-situational characteristics of the larger environment). Traits that appear to be associated with good affective copers include a differentiated sense of self, a strong sense of self-determination, and the ability to depersonalize.
Sociocultural systems model and subtheory
The sociocultural systems subtheory concentrates on major causes and sociocultural correlates of interpersonal acceptance–rejection in a global context. The subtheory looks at larger sociocultural factors that influence why significant others show acceptance or rejection. Larger social institutions like the economic system, family structure, and political organization tend to shape how much acceptance parents and other significant persons offer. Additionally, the cultural context can also influence how children and youth perceive their acceptance or rejection, and how they react to or cope with it. The system is also bidirectional, because a culture's tendency toward acceptance or rejection may result in different institutionalized expressive systems and behaviors, which can include people's spiritual and artistic beliefs and behaviors.
Warmth dimension
IPARTheory posits that all significant interpersonal relationships fall along the warmth dimension, from interpersonal acceptance to interpersonal rejection, depending on how much love or warmth a person perceives from a significant other. The specific physical, verbal, and symbolic behaviors associated with interpersonal acceptance or rejection may differ by culture or society, but the effects of feeling acceptance or rejection remain stable across cultures. Interpersonal acceptance is marked by warmth, affection, comfort, emotional support, and love which is expressed by the significant other. Relationships that are high in interpersonal rejection, on the other hand, are characterized by an absence of positive feelings and may also include emotional withdrawal, as well as the presence of psychologically or physically hurtful behaviors.
Rejection may be experienced by any combination of four expressions: coldness or lack of affection, hostility or aggression, indifference or neglect, and undifferentiated rejection. Undifferentiated rejection is based on the perception of the individual that a parent (or an attachment figure) or other person who is important to the individual does not care about them, want them, or love them, though there may not be any behavioral manifestations from the prior three categories of rejection.
History
IPARTheory was developed by Ronald P. Rohner. He started working on issues of interpersonal acceptance and rejection as a graduate student at Stanford University in 1959. While carrying out cross-cultural analyses on the outcomes of the rejection process of children, he found that parental rejection during childhood appeared to result in similar negative outcomes across the globe. Early on, Rohner's research focused heavily on parent-child relationships and the theory was named "parental acceptance–rejection theory?" (PARTheory) after he and Evelyn C. Rohner edited a special issue of Behavior Science Research (now Cross-Cultural Research) on "Worldwide Tests of Parental Acceptance-Rejection Theory" in 1980. However, by the year 2000, Rohner and other researchers like Abdul Khaleque had started investigating the effects of rejection in non-parental significant relationships. Khaleque carried out a study which found that the effects of intimate-partner rejection had similar effects in adulthood to those of parental rejection in childhood. Following that research, other attachment figures were included in IPARTheory research, including peers, best friends, siblings, teachers, coaches, in-laws, and supervisors/managers. In 2014, the name of the theory was changed to "interpersonal acceptance–rejection theory" (IPARTheory) to reflect the broadened scope of the theory and research.
References
Further reading
Rohner's TED Talk on IPARTheory
The International Society for Interpersonal Acceptance-Rejection
Social concepts
Sociological terminology
Developmental psychology | Interpersonal acceptance–rejection theory | [
"Biology"
] | 1,673 | [
"Behavioural sciences",
"Behavior",
"Developmental psychology"
] |
68,417,587 | https://en.wikipedia.org/wiki/Toshiba%20Libretto%20W100 | The Toshiba Libretto W100 is a dual-touchscreen computer from the Toshiba Libretto series.
History
The W100 was released for the 25th anniversary of Toshiba in the laptop industry. It was released in July 2010.
Specifications
Windows 7
Two capacitive touchscreens
Intel Pentium U5400
Reception
Engadget noted that the software was unstable in an early model. Techradar noted that the model is "on the chunky size". Popular Mechanics noted the clever design. ZDnet noted the high price tag.
Further developments
Later in 2010, Acer also developed a laptop with two touchscreens.
References
External links
User manual of the Toshiba Libretto W100
Libretto W100
Tablet computers introduced in 2010 | Toshiba Libretto W100 | [
"Technology"
] | 152 | [
"Computing stubs",
"Computer hardware stubs"
] |
68,418,029 | https://en.wikipedia.org/wiki/Smart%20plug | A smart plug is a power plug and socket (also known as a wall plug, outlet, or electrical connector) which can be fitted between power cords and sockets to function as a remote-controlled power switch. As such, smart plugs can be used to make "dumb" electrical equipment smart, and thereby enable such devices for home automation or building automation purposes.
Smart plugs can, for example, be controlled via a mobile application, a smart home hub or a virtual assistant. Examples of protocols used for communication with smart plugs include Wi-Fi, Bluetooth, Zigbee and Z-Wave. Many smart plugs have a built-in ammeter so that electric energy consumption (measured in kilowatt-hours) of the connected equipment can be monitored. Smart plugs often have a slim profile so as not to hinder access to neighbouring sockets in a wall outlet or power strip.
See also
Wireless light switch
Time switch
References
External links
TP-LINK HS100 Wi-Fi Smart Plug Review
Electrical connectors
Electricity
Home automation | Smart plug | [
"Technology"
] | 212 | [
"Home automation"
] |
68,418,091 | https://en.wikipedia.org/wiki/Kleptotrichy | Kleptotrichy is the stealing of mammal hair by birds for use in their nests.
The phenomenon was first defined scientifically in a journal article published in July 2021. Scientists largely studied it from videos posted to YouTube. The study found that the tufted titmouse was among the species of birds which most frequently engaged in kleptotrichy.
References
Bird behavior | Kleptotrichy | [
"Biology"
] | 79 | [
"Behavior by type of animal",
"Behavior",
"Bird behavior"
] |
68,419,434 | https://en.wikipedia.org/wiki/Hypomyces%20lateritius | Hypomyces lateritius, the ochre gillgobbler, is a parasitic ascomycete fungus that grows on certain species of Lactarius mushrooms, improving their flavor and densifying the flesh. Hosts include L. camphoratus, L. chelidonium, L. controversus, L. deliciosus, Lactarius indigo, L. rufus, L. salmonicolor, L. sanguifluus, L. semisanguifluus, L. tabidus, L. trivialis, and L. vinosus.
It is a microscopic fungus causing the formation of a macroscopic whitish subiculum over the hymenium of its host species, preventing gill formation. Presence of H. lateritius also often deforms the cap and stipe. Parasitization by H. lateritius does not prevent latex from forming when the flesh is cut.
Distribution
Hypomyces lateritius can be found wherever Lactarius species can be found, in North America from Alaska to Mexico and in Europe from the Iberian Peninsula to Ukraine. In Asia in Kazakhstan, Kyrgyzstan and Western Siberia. It has also been reported in New Zealand and South Africa.
Synonyms
Sphaeria lateritia Fries, Syst. Mycol. 2: 338. 1823.
Hypocrea lateritia (Fr.) Fries, Summa Veg. Scand. 383.1849.
Peckiella lateritia (Fr.) Maire, Ann. Mycol. 4: 331.1906.
Byssonectria lateritia (Fr.) Petch, J. Bot. Lond. 75: 220.1937.
Hypomyces volemi Peck, Bull. Torrey Club 27: 20. 1900.
Peckiella hymenioides Peck, Bull. Torrey Club 34: 102.1907.
Hypomyces camphorati Peck, New York State Bull. 205:23. 1905 (1906).
Peckiella camphorati (Peck) Seaver, Mycologia 2: 68.1910.
Hypomyces camphorati (syn. Peckiella camphorati) is sometimes treated as a separate species from H. lateritius. Subiculum of specimens with L. camphoratus host tends more yellowish, and displays slightly larger ascospores. More research is required to determine whether H. lateritius is a single species or a species complex.
References
External links
Hypocreaceae
Edible fungi
Parasitic fungi
Taxa named by Elias Magnus Fries
Fungus species
[[Category:Fungi described in | Hypomyces lateritius | [
"Biology"
] | 537 | [
"Fungi",
"Fungus species"
] |
68,419,561 | https://en.wikipedia.org/wiki/L%2098-59 | L 98-59 (TOI-175, TIC 307210830) is a bright M dwarf star, located in the constellation of Volans, at a distance of , as measured by the Gaia spacecraft.
Broadband photometry shows that it is an M3 dwarf star with three confirmed terrestrial-sized planets in transit, which were announced in March 2019 by TESS, as well as a fourth non-transiting planet and fifth candidate.
In August 2021, new evidence was announced for a fifth, potentially habitable planet, labeled L 98-59 f. Though still unconfirmed, this planet is believed to have 2.46 times Earth's mass, and an orbital period of 23.15 days.
Planetary system
The three inner planets of L 98-59 were discovered in 2019 by TESS. The potential super-Venus planet L 98-59 e was discovered in 2021, along with potentially habitable (located in the middle of the habitable zone) super-Earth candidate L 98-59 f. In September 2021, suggested tests of the abilities of the Hubble Space Telescope and the upcoming James Webb Space Telescope to detect and describe the atmospheric features of the three inner planets were reported.
The two innermost planets, L 98-59 b and c, as well as L 98-59 e are possibly hot rocky worlds. L 98-59 d has a low density, indicating large amounts of water, potentially making up as much as 30% of its entire mass. It may therefore be covered in a deep global ocean. Hubble observations of the three transiting planets in 2022 have found no clear evidence of atmospheres, with high mean molecular weight atmospheres, cloudy or hazy atmospheres, or no atmospheres being consistent with the observed flat spectra. One study found some evidence of an atmosphere on L 98-59 c, which has yet to be confirmed as of 2023. Transmission spectroscopy by the JWST suggest that L 98-59 d might have a sulfur-rich atmosphere.
Also, ExoFOP list of TESS candidates includes fourth transiter, TOI-175.04 - if confirmed, this sub-earth would be innermost in this system; due to low mass (lighter than L 98-59 b) and intense UV radiation, it probably lacks any kind of thick atmosphere.
Gallery
See also
References
External links
New ESO observations show rocky exoplanet has just half the mass of Venus (ESO press release)
TESS – Official Website
Smallest exoplanet found so far (video; 1:53; NASA; June 2019)
M-type main-sequence stars
Planetary systems with four confirmed planets
175
J08180763-6818468
Volans | L 98-59 | [
"Astronomy"
] | 552 | [
"Volans",
"Constellations"
] |
68,423,077 | https://en.wikipedia.org/wiki/The%20Phrenologist%20Coon | "The Phrenologist Coon" is a 1901 song written by African-American entertainer Ernest Hogan with music by Will Accooe. Bert Williams recorded it on Victor Records and sheet music was published for it. It was produced by Williams and Walker Co. and published by Jos. W. Stern & Co. in New York City.
The song's lyrics describe a "conjureman" ironically engaging in phrenology – the pseudoscientific study of human characteristics according to the shape of the skull. "In what is at first glance a demeaning stereotype, 'The Phrenologist's Coon' might, indeed, be something much more involved, because it suggests that black artists were self-consciously dialoging with political context prior to the modernist explorations of affirmative black identity by the Harlem Renaissance writers," suggests Paula J. Massood in Making a Promised Land: Harlem in Twentieth-Century Photography and Film (2013).
The tune as a schottische was used for the 1902 song "Maiden with the Dreamy Eyes" by Cole and Johnson.
References
External links
Recording via Discography of American Historical Recordings
1901 songs
Victor Records singles | The Phrenologist Coon | [
"Biology"
] | 241 | [
"Phrenology",
"Biology theories",
"Obsolete biology theories"
] |
68,425,069 | https://en.wikipedia.org/wiki/Rodriguez%20well | A Rodriguez well (or Rodwell) is a type of well envisioned by Swiss glaciologist Henri Bader of Rutgers University and developed by engineer Raul Rodriguez of the United States Army for economical harvesting of drinking water in polar areas. The project began as a subproject of the Army's Camp Century base in Greenland, created as a demonstration for affordable ice-cap military outposts or bases for scientific research.
Background
U.S. Army engineer Raúl Rodríguez-Torrent (1921-1985) was born in Rio Piedras, Puerto Rico in August 1921. In 1940 he enlisted in the U.S. Army and later became an engineer at the United States Army Corps of Engineers (USACE).
Developed at Camp Century in Greenland during the early 1960s, a Rodriguez Well (Rodwell), uses heat exchangers and a submersible pump to create a cavity deep under a glacier’s surface and cycle the heated water up an ice shaft, siphoning a portion of the flow for consumption before sending the rest back down to the well. Camp Century was a preliminary camp for Project Iceworm whose end goal was to install a vast network of nuclear missile launch sites that could survive a first strike. If this model were found to be effective, an efficient means of supplying water to staff stationed on site needed to be developed. Project Iceworm was a top secret United States Army program of the Cold War, which aimed to build a network of mobile nuclear missile launch sites under the Greenland ice sheet. The ultimate objective of placing medium-range missiles under the ice — close enough to strike targets within the Soviet Union — was kept secret from the Government of Denmark.
Means of operation
Heated water is used to melt a shaft over a hundred feet deep, eventually forming a cavity beneath the surface at the point where the shaft ends. By continuously replenishing this pool of heated water, the deep pocket of melted water gradually expands, renewing the supply of fresh water available to be pumped to the surface. The process was inspired by the observation that room temperature sewage injected into the arctic surface eventually formed a pocket around 100 feet down which would not refreeze as long as more sewage was continuously injected. The lifespan of a Rodriguez well is over seven years, ending when the depth of the cavity becomes too deep for the facility to efficiently heat and recirculate water.
Current uses
A Rodriguez well was driven at the National Science Foundation's Amundsen–Scott South Pole Station.
Potential use on Mars
NASA is presently working with the Cold Regions Research and Engineering Laboratory of the US Army Corps of Engineers to design a proof of concept of a Rodriguez well usable in polar regions of Mars.
See also
Bader Glacier
References
Water supply
Habitat | Rodriguez well | [
"Chemistry",
"Engineering",
"Environmental_science"
] | 550 | [
"Hydrology",
"Water supply",
"Environmental engineering"
] |
68,425,201 | https://en.wikipedia.org/wiki/Time%20in%20Burundi | Time in Burundi is given by a single time zone, officially denoted as Central Africa Time (CAT; UTC+02:00). Burundi does not observe daylight saving time.
IANA time zone database
In the IANA time zone database, Burundi is given one zone in the file zone.tab – Africa/Bujumbura. "BI" refers to the country's ISO 3166-1 alpha-2 country code. Data for Burundi directly from zone.tab of the IANA time zone database; columns marked with * are the columns from zone.tab itself:
See also
List of time zones by country
List of UTC time offsets
References
External links
Current time in Burundi at Time.is
Time in Burundi at TimeAndDate.com
Time by country
Geography of Burundi
Time in Africa | Time in Burundi | [
"Physics"
] | 161 | [
"Spacetime",
"Physical quantities",
"Time",
"Time by country"
] |
68,425,612 | https://en.wikipedia.org/wiki/Time%20in%20Mozambique | Time in Mozambique is given by a single time zone, officially denoted as Central Africa Time (CAT; UTC+02:00). Mozambique has never observed daylight saving time.
History
Mozambique adopted UTC+02:00 (Central Africa Time; CAT) unofficially in 1903, and officially on 26 May 1911.
IANA time zone database
In the IANA time zone database, Mozambique is given one zone in the file zone.tab – Africa/Maputo. "MZ" refers to the country's ISO 3166-1 alpha-2 country code. Data for Mozambique directly from zone.tab of the IANA time zone database; columns marked with * are the columns from zone.tab itself:
See also
List of time zones by country
List of UTC time offsets
References
External links
Current time in Mozambique at Time.is
Time in Mozambique at TimeAndDate.com
Time by country
Geography of Mozambique
Time in Africa | Time in Mozambique | [
"Physics"
] | 186 | [
"Spacetime",
"Physical quantities",
"Time",
"Time by country"
] |
71,289,551 | https://en.wikipedia.org/wiki/Alt-right%20pipeline | The alt-right pipeline (also called the alt-right rabbit hole) is a proposed conceptual model regarding internet radicalization toward the alt-right movement. It describes a phenomenon in which consuming provocative right-wing political content, such as antifeminist or anti-SJW ideas, gradually increases exposure to the alt-right or similar far-right politics. It posits that this interaction takes place due to the interconnected nature of political commentators and online communities, allowing members of one audience or community to discover more extreme groups. This process is most commonly associated with and has been documented on the video platform YouTube, and is largely faceted by the method in which algorithms on various social media platforms function through the process recommending content that is similar to what users engage with, but can quickly lead users down rabbit-holes. The effects of YouTube's algorithmic bias in radicalizing users has been replicated by one study, although two other studies found little or no evidence of a radicalization process.
Many political movements have been associated with the pipeline concept. The intellectual dark web, libertarianism, the men's rights movement, and the alt-lite movement have all been identified as possibly introducing audiences to alt-right ideas. Audiences that seek out and are willing to accept extreme content in this fashion typically consist of young men, commonly those that experience significant loneliness and seek belonging or meaning.
The alt-right pipeline may be a contributing factor to domestic terrorism. Many social media platforms have acknowledged this path of radicalization and have taken measures to prevent it, including the removal of extremist figures and rules against hate speech and misinformation. Left-wing movements, such as BreadTube, also oppose the alt-right pipeline and "seek to create a 'leftist pipeline' as a counterforce to the alt-right pipeline."
Process
Use of the internet allows individuals with heterodox beliefs to alter their environment, which in turn has transformative effects on the user. Influence from external sources such as the internet can be gradual so that the individual is not immediately aware of their changing understanding or surroundings. Members of the alt-right refer to this radicalization process as "taking the red pill" in reference to the method of immediately achieving greater awareness in The Matrix. This is in contrast to the gradual nature of radicalization described by the alt-right pipeline. Many on the far-right recognize the potential of this radicalization method and actively share right-wing content with the intention of gradually radicalizing those around them. The use of racist imagery or humor may be used by these individuals under the guise of irony or insincerity to make alt-right ideas palpable and acceptable to newer audiences. The nature of internet memes means they can easily be recreated and spread to many different internet communities.
YouTube has been identified as a major element in the alt-right pipeline. This is facilitated through an "Alternative Influence Network", in which various right-wing scholars, pundits, and internet personalities interact with one another to boost performance of their content. These figures may vary in their ideologies between conservatism, libertarianism, or white nationalism, but they share a common opposition to feminism, progressivism, and social justice that allows viewers of one figure to quickly acclimate to another. They often prioritize right-wing social issues over right-wing economic issues, with little discussion of fiscal conservatism. Some individuals in this network may not interact with one another, but a collection of interviews, internet debates, and other interactions create pathways for users to be introduced to new content.
YouTube's algorithmic system for recommending videos allows users to quickly access content similar to what they have previously viewed, allowing them to more deeply explore an idea once they have expressed interest. This allows newer audiences to be exposed to extreme content when videos that promote misinformation and conspiracy theories gain traction. When a user is exposed to certain content featuring certain political issues or culture war issues, this recommendation system may lead users to different ideas or issues, including Islamophobia, opposition to immigration, antifeminism, or reproduction rates. Recommended content is often somewhat related, which creates an effect of gradual radicalization between multiple issues, referred to as a pipeline.
At times, the platform will also recommend these videos to users that had not indicated interest in these viewpoints. Radicalization also takes place in interactions with other radicalized users online, on varied platforms such as Gab, Reddit, 4chan, or Discord. Major personalities in this chain often have a presence on Facebook and Twitter, though YouTube is typically their primary platform for messaging and earning income.
The alt-right pipeline mainly targets angry white men, including those who identify as incels, reflecting the misogyny of the alt-right. Harvard Political Review has described this process as the "exploitation of latent misogyny and sexual frustration through 'male bonding' gone horribly awry". The pipeline also targets people with self-doubt.
Content
The alt-right pipeline has been found to begin with the intellectual dark web community, which is made up of internet personalities that are unified by an opposition to identity politics and political correctness, such as Joe Rogan, Ben Shapiro, Dave Rubin, and Jordan Peterson. The intellectual dark web community overlaps and interacts with the alt-lite community, such as Steven Crowder, Paul Joseph Watson, Mark Dice, and Sargon of Akkad. This community in turn overlaps and interacts with the alt-right community, such as James Allsup, Black Pigeon Speaks, Varg Vikernes, and Red Ice. The most extreme endpoint often involves fascism or belief in an international Jewish conspiracy, though the severity of extremism can vary between individuals.
Alt-right content on the internet spreads ideology that is similar to earlier white supremacist and fascist movements. The internet packages the ideology differently, often in a way that is more palatable and thus is more successful in delivering it to a larger number of people. Due to the conservative nature of the alt-right, much of the ideology is associated with the preservation of traditional values and ways of living. This creates a susceptibility toward conspiracy theories about secret forces that seek to destroy traditional ways of life.
The antifeminist Manosphere has been identified as another early point in the alt-right pipeline. The men's rights movement often discusses men's issues more visibly than other groups, attracting young men with interest in such issues when no alternative is made available. Many right-wing internet personalities have developed a method to expand their audiences by commenting on popular media; videos that criticize movies or video games for supporting left-wing ideas are more likely to attract fans of the respective franchises.
The format presented by YouTube has allowed various ideologies to access new audiences through this means. The same process has also been used to facilitate access to anti-capitalist politics through the internet community BreadTube. This community was developed through the use this pipeline process to introduce users to left-wing content and mitigate exposure to right-wing content, though the pipeline process has been found to be less effective for left-wing politics due to the larger variety of opposing left-wing groups that limits interaction and overlap. This dichotomy can also cause a "whiplash polarization" in which individuals are converted between far-right and far-left politics.
Psychological factors
The psychological factors of radicalization through the alt-right pipeline are similar to other forms of radicalization, including normalization, acclimation, and dehumanization. Normalization involves the trivialization of racist and antisemitic rhetoric. Individuals early in the alt-right pipeline will not willingly embrace such rhetoric, but will adopt it under the guise of dark humor, causing it to be less shocking over time. This may sometimes be engineered intentionally by members of the alt-right to make their beliefs more palatable and provide plausible deniability for extreme beliefs. Acclimation is the process of being conditioned to seeing bigoted content. By acclimating to controversial content, individuals become more open to slightly more extreme content. Over time, conservative figures appear too moderate and users seek out more extreme voices. Dehumanization is the final step of the alt-right pipeline, where minorities are seen as lesser or undeserving of life and dehumanizing language is used to refer to people that disagree with far-right beliefs.
The process is associated with young men that experience loneliness, meaninglessness, or a lack of belonging. An openness to unpopular views is necessary for individuals to accept beliefs associated with the alt-right pipeline. It has been associated with contrarianism, in which an individual uses the working assumption that the worldviews of most people are entirely wrong. From this assumption, individuals are more inclined to adopt beliefs that are unpopular or fringe. This makes effective several entry points of the alt-right pipeline, such as libertarianism, in which ideologies attract individuals with traits that make them susceptible to radicalization when exposed to other fringe ideas. Motivation for pursuing these communities varies, with some people finding them by chance while others seek them out. Interest in video games is associated with the early stages of the alt-right pipeline.
Along with algorithms, online communities can also play a large part in radicalization. People with fringe and radical ideologies can meet other people who share, validate and reinforce those ideologies. Because people can control who and what they engage with online, they can avoid hearing any opinion or idea that conflicts with what their prior beliefs. This creates an echo chamber that upholds and reinforces radical beliefs. The strong sense of community and belonging that comes with it is a large contributing factor for people joining the alt-right and adopting it as an identity.
Concerns and prevention
Internet radicalization correlates with an increase in lone wolf attacks and domestic terrorism. The alt-right pipeline has been associated with the Christchurch mosque shootings, in which a far-right extremist killed 51 Muslim worshipers in Christchurch, who directly credited the Internet for the formation of his beliefs in his manifesto. The informal nature of radicalization through the alt-right pipeline allows radicalization to occur at an individual level, and radicalized individuals are able to live otherwise normal lives offline. This has complicated efforts by experts to track extremism and predict acts of domestic terrorism, as there is no reliable way of determining who has been radicalized or whether they are planning to carry out political violence. Harassment campaigns against perceived opponents of the alt-right movement are another common effect of radicalization.
Many social media platforms have recognized the potential of radicalization and have implemented measures to limit its prevalence. High-profile extremist commentators such as Alex Jones have been banned from several platforms, and platforms often have rules against hate speech and misinformation. In 2019, YouTube announced a change to its recommendation algorithm to reduce conspiracy theory related content. Some extreme content, such as explicit depictions of violence, are typically removed on most social media platforms. On YouTube, content that expresses support of extremism may have monetization features removed, may be flagged for review, or may have public user comments disabled.
Studies
A September 2018 study published by the Data & Society Research Institute found that 65 right-wing political influencers use YouTube's recommendation engine—in concert with conventional brand-building techniques such as cross-marketing between similar influencers—to attract followers and radicalize their viewers into a particular right-wing ideology. An August 2019 study conducted by the Universidade Federal de Minas Gerais and École polytechnique fédérale de Lausanne, and presented at the ACM Conference on Fairness, Accountability, and Transparency 2020 used information from the earlier Data & Society research and the Anti-Defamation League (ADL) to categorize the levels of extremism of 360 YouTube channels. The study also tracked users over an 11-year period by analysing 72 million comments, 2 million video recommendations, and 10,000 channel recommendations. The study found that users who engaged with less radical right-wing content tended over time to engage with more extremist content, which the researchers argued provides evidence for a "radicalization pipeline".
A 2020 study published in The International Journal of Press/Politics argued that the "emerging journalistic consensus" that YouTube's algorithm radicalizes users to the far-right "is premature." Instead, the study proposes a "'Supply and Demand' framework for analyzing politics on YouTube."
A 2021 study published in the Proceedings of the National Academy of Sciences found "no evidence that engagement with far-right content is caused by YouTube recommendations systematically, nor do we find clear evidence that anti-woke channels serve as a gateway to the far right." Instead, the study found that "consumption of political content on YouTube appears to reflect individual preferences that extend across the web as a whole." A 2022 study published by the City University of New York found that "little systematic evidence exists to support" the claim that YouTube's algorithm radicalizes users, adding that exposure to extremist views "on YouTube is heavily concentrated among a small group of people with high prior levels of gender and racial resentment", and that "non-subscribers are rarely recommended videos from alternative and extremist channels and seldom follow such recommendations when offered."
See also
Algorithmic radicalization
Filter bubble
Incitement to ethnic or racial hatred
Internet manipulation
Nonviolent extremism
Online youth radicalization
Right-wing populism
Right-wing terrorism
References
2010s neologisms
Alt-right
Internet terminology
Internet trolling
Manosphere
Political neologisms
YouTube controversies
Radicalization | Alt-right pipeline | [
"Technology"
] | 2,797 | [
"Computing terminology",
"Internet terminology"
] |
71,290,344 | https://en.wikipedia.org/wiki/HD%2068375 | HD 68375 (HR 3216) is a solitary star in the northern circumpolar constellation Camelopardalis. It is faintly visible to the naked eye with an apparent magnitude of 5.54 and is estimated to be 289 light years distant. However, it is receding with a heliocentric radial velocity of .
HD 68375 has a stellar classification of G8 III, indicating that it is a red giant. It is currently on the horizontal branch, generating energy via fusion inside a helium core. Specifically, it is a red clump star, at the cool end of the horizontal branch where stars with near-solar metallicity are found. After approximately 1 billion years, the star now has a radius of and an effective temperature of , giving a yellow hue. Nevertheless, it has nearly double the mass of the Sun and radiates at 49 times the luminosity of the Sun from its enlarged photosphere. HD 68375 is slightly metal deficient with a metallicity 76% that of the Sun and spins with a poorly constrained projected rotational velocity of .
References
G-type giants
Horizontal-branch stars
Camelopardalis
BD+76 00310
068375
040793
3216 | HD 68375 | [
"Astronomy"
] | 253 | [
"Camelopardalis",
"Constellations"
] |
71,290,907 | https://en.wikipedia.org/wiki/MGI%20%28company%29 | MGI or MGI Tech is a Chinese biotechnology company, which provides a line of products and technologies that serves the genetic sequencing, genotyping and gene expression, and proteomics markets. Its headquarters are located in Shenzhen, Guangdong, China.
History
In 2016, MGI was founded as a subsidiary of BGI Group. It manufactures high-throughput genetic sequencing systems and other products for use in the life sciences and health care sectors. As of July 2022, the company's operation is divided into two primary business segments: genetic sequencers and laboratory automation systems.
MGI was a subsidiary of BGI Group before, it was spun out and listed on the Shanghai stock exchange in 2022.
In May 2020, MGI raised $1 billion in series B funding from IDG Capital and CPE China Fund. In December 2020, the company submitted its IPO application to Shanghai Stock Exchange STAR Market. In September 2021, the company has won the approval for its IPO on Shanghai Stock Exchange STAR Market’s high-tech board.
In 2024, MGI lost more than a third of its market capitalization after the US Congress introduced legislation to prohibit American health data being sent to China.
Subsidiaries
Complete Genomics
In March 2013, Complete Genomics was acquired by BGI Group. After the acquisition, Complete Genomics moved to San Jose, and in June 2018 became part of MGI. The acquisition was the one of the outcomes of $1.5 billion 'collaborative funds' i.e., '10 years loan' which was initially provided by China Development Bank to acquire all 128 of Illumina, Inc.'s newest and fastest next-generation sequencers including HiSeq 2000.
Research and development
The company is known for manufacturing DNA sequencers based on low-cost DNA nanoball sequencing technologies which was refined further after the acquisition of Complete Genomics. The refinement included combinatorial probe anchor synthesis technologies which involves loading DNA nanoballs (DNBs) onto a patterned array chip using a fluidic system. Subsequently, a sequencing primer is added to the adaptor region of the DNBs in order to hybridize them.
Criticism
On October 31, 2019, the Chairman of the Senate Finance Committee, Chuck Grassley, and Senator Marco Rubio wrote a joint letter to Alex Azar, the Secretary of the Department of Health and Human Services and Seema Verma, the Administrator of the Centers for Medicare & Medicaid Services (CMS) raised their concerns against MGI, regarding the circumstances under which the CMS may finance it to process American citizens' genomic or exome data.
MGI asserted that it is “a supplier of instruments and consumables for customers to use in their own labs” and does not provide any genomic sequencing services. “MGI does not own, control, handle, or even access samples or genetic data, only MGI’s customers do. There is no risk that MGI will have access to any health records or genetic data from customers,” the company stated.
Litigation
Patents infringement lawsuit
In November 2021, a federal jury in California concluded that MGI America (in its capacity as an affiliate of BGI Group) had infringed Illumina, Inc.'s patents. Accordingly, they awarded Illumina damages of $8 million.
In March 2022, Illumina persuaded a U.S. District Judge to prolong the restriction on MGI America selling its CoolMPS sequencers in the United States for six months until August 2022, when Illumina's patent expires.
“Two-channel” DNA sequencing lawsuit
Complete Genomics, a research subsidiary of MGI, filed a lawsuit in May 2019, alleging that Illumina's "two-channel" DNA sequencing chemistry violates two patents for the technology that deduces the identification of each nucleotide from two signals. The NovaSeq 6000, the NextSeq 500/550/550x, and 1000/2000 Series, as well as the MiniSeq, were all the focus of the lawsuit against Illumina. Additionally, it targeted Illumina's cluster generation & sequencing, and library preparation kits, all of which are interoperable with one or more platforms.
In May 2022, A jury in Delaware concluded that Illumina's “two-channel” sequencing chemistry infringes on two patents owned by MGI Tech through its subsidiary Complete Genomics. As a result of this finding, the jury awarded $333.8 million in damages to the company. The jury also dismissed Illumina's assertions that the patents were invalid. The verdict also invalidated three of Illumina's patents that the firm had asserted in a countersuit claiming MGI Tech had infringed on Illumina's patents.
References
External links
Laboratory equipment manufacturers
Manufacturing companies based in Shenzhen
Research support companies
Chinese companies established in 2016
Biotechnology companies of China
Genomics companies
DNA sequencing
2016 in Shenzhen | MGI (company) | [
"Chemistry",
"Biology"
] | 1,024 | [
"Molecular biology techniques",
"DNA sequencing"
] |
71,291,532 | https://en.wikipedia.org/wiki/Halorubrum%20californiense | Halorubrum californiense is a halophilic Archaeon in the family of Halorubraceae. It was isolated from saline environments solar saltern in Newark, California.
References
Euryarchaeota
Archaea described in 2008 | Halorubrum californiense | [
"Biology"
] | 53 | [
"Archaea",
"Archaea stubs"
] |
71,291,592 | https://en.wikipedia.org/wiki/Halorubrum%20orientale | Halorubrum orientale is a halophilic Archaeon in the family of Halorubraceae.
References
Euryarchaeota
Archaea described in 2006 | Halorubrum orientale | [
"Biology"
] | 36 | [
"Archaea",
"Archaea stubs"
] |
71,292,021 | https://en.wikipedia.org/wiki/INPUD | INPUD (International Network for People who Use Drugs) is an international non-profit organization grouping local groups and collectives of people who use illicit drugs, which aims at "A world where people who use drugs are free to live their lives with dignity." INPUD was founded in 2006 in Vancouver, Canada, and formally launched in Copenhagen, Denmark, on 1 November 2008.
History
Although drug users' activist groups have existed all across the world for decades, the inception of an international network of people who use drugs traces back to Canada. On the one hand, in practice, in British Columbia, the leadership of local users groups such as VANDU inspired the creation of a broader network. According to Kerr et al, "in 1997 a group of Vancouver residents, including drug users, activists, and others, came together to form a drug user organization as a means to addressing the health crisis among local injecting drug users" and called it the Vancouver Area Network of Drug Users (VANDU) Following the launch of this local organization, a series of meetings and gathering were set up. On the other hand, in theory, NGOs such as the Canadian HIV/AIDS Legal Network had prepared background documents such as the report Nothing About Us Without Us (Greater, Meaningful Involvement of People Who Use Illegal Drugs: A Public Health, Ethical, and Human Rights Imperative) which emphasized that measures of harm reduction related to drug use should happen "from the ground up, with people who use drugs involved in every part of the process".
Between 30 May and 4 April 2006, the 17th International Conference on the Reduction of Drug Related Harm was held in Vancouver. Over 1300 attendees from more than 60 countries reportedly attended. One of the highlighted outcome was the adoption, on the first day of the conference, of the Vancouver Declaration, subtitled "Why the world needs an international network of activists who use drugs." It served as the starting point to the development of an international network and, subsequently, regional and local groupings. The Vancouver Declaration "highlights the history of marginalization and discrimination against people who use drugs and promotes the right to self-representation and empowerment".
The NGO was formally created as a Belgian non-profit organization, and launched on 1 November 2008. INPUD also declared the first of November an International Drug Users Day.
Purpose and activities
INPUD considers itself "a global peer-based organization that seeks to promote the health and defend the rights of people who use drugs". On its website, the organization is described as follows:At its launch, INPUD declared the following five aims:
To advocate and lobby for the rights of drug users on the world stage,
To bring the voices of drug users to the policy table,
To support and seed the development of self-determining networks of drug users that advocate for the rights of drug users,
To promote and advocate for harm reduction as a means of supporting safer drug use,
To build alliances with like-minded organizations in the drugs field and civil society to further the first four aims of INPUD.
In its 2021-2024 plan, INPUD declared as a "vision": "A world where people who use drugs are free to live their lives with dignity."
More generally, the goals and purposes of INPUD are laid down in the Vancouver Declaration. After its launch, in 2007, INPUD conducted "a six-month on-line research on the profile of drug users' (DU) activism and self-organisation." The study gathered information about the types of the drug users' organizations world-wide, the level of involvement of drug users communities in activism, geographical coverage, goals, funding sources, etc. The study was then used to foster capacity-building into local organizations of people who use drugs.
In 2015, INPUD held consultations in Dar es Salaam, Bangkok, London, Tbilisi, and virtually, with representatives of 24 drug users groups originating from 28 countries. This resulted in the adoption of the Consensus Statement on Drug Use Under Prohibition, a manifesto which focusses on human rights, health, and the law in relation to people who use drugs, from the perspective of people who use drugs themselves. As explained on the organization's website, "This is a statement of essential demands. These demands must be met if the harms experienced by people who use drugs are to be ended." The Consensus Statement reinforces the Vancouver Declaration and specifies the goals of INPUD and its local groups.
INPUD and its local chapters have increasingly been involved as observers and participant in United Nations conferences on drugs and health-related issues. In 2017, INPUD collaborated with the UN Office on Drugs and Crime, World Health Organization, Joint UN Programme on HIV/AIDS, UN Population Fund and UN Development Programme to publish a guide titled Implementing Comprehensive HIV and HCV Programmes with People Who Inject Drugs: Practical Guidance for Collaborative Interventions.
Regional organisations
One of the goals of INPUD is "developing and supporting regional and national drug user networks and emerging leaders through technical support"
Accordingly, INPUD is subdivided into seven regional or topical groupings themselves gathering local groups. Regional or topical INPUD members are organized as their own networks of people who use drugs, with the same aims and objectives as INPUD's. It receives funding from the Robert Carr Fund to develop the consortium of networks.
As of July 2022, there are six regional groups plus one topical group (INWUD).
International Network of Women who Use Drugs (INWUD)
Founded in 2010, INWUD is the global network of women who use drugs. It has been shedding light on gender-specific issues like sexual and reproductive health, or gender-specific repression of women who use drugs (such as forced abortion or sterilization) as well as issues of stigma.
African Network of People who Use Drugs (AfricaNPUD)
AfricaNPUD is a network founded in 2015 by and for African people who use drugs, and headquartered in Tanzania. It is currently present across 15 countries in the African region. AfricaNPUD accepts membership from both individual members and community-led organizations.
Asian Network of People who use Drugs (ANPUD)
ANPUD is headquartered in Thailand.
Eurasian Network of People who Use Drugs (ENPUD)
ENPUD is focused on the Eastern Europe and Centra Asia (EECA) region. During the Russo-Ukrainian War, the network has been engaged in providing emergency assistance and treatment for people who use drugs.
European Network of People who Use Drugs (EuroNPUD)
Founded 2011, EuroNPUD is present across the European Union and neighboring countries (UK, Switzerland, Norway). EuroNPUD claims presence in 12 European countries via local unions and groups of people who use drugs (Swedish Drug Users Union, CATNPUD and Metzineres in Catalonia, ASUD in France, etc.).
Latin American Network of People who Use Drugs (LANPUD)
Focused on Latin America and the Caribbean regions, it was launched on 26 October 2012 in Salvador de Bahia, Brasil. As of July 2022, LANPUD claims presence in 17 countries.
Middle East and North Africa Network of People who Use Drugs (MENANPUD)
MENANPUD is present in the Middle East and North Africa (MENA) region.
Leadership
As of July 2022, the Board is formed by:
Judy Chang (executive director since 2017),
Phumlani Malinga (Communications Officer since 2022),
Tina Chkhaidze (Finance Manager since 2018),
Rico Gustav (Senior Technical Advisor),
Kim Jackson (Office Manager since 2020),
Annie Madden (Robert Carr Fund's Exceptional Opportunity Project Lead),
Aditia Taslim (Advocacy Officer).
Olga Szubert (Programme Oversight since 2021),
Gayané Arustamyan (Programme Manager since 2021)
See also
Cannabis rights
Drugs
Drug liberalization
Drug policy
Harm reduction
NGO
Psilocybin decriminalization in the United States
UNODC
UNAIDS
WHO
References
External links
(INPUD's official website)
Addiction and substance abuse organizations
Drug control law
Political controversies
Drug culture
Drug policy
Drug policy organizations
Public health organizations
Harm reduction
International medical and health organizations
International charities
Organizations established in 2006
Organizations established in 2008
2006 establishments in Canada | INPUD | [
"Chemistry"
] | 1,683 | [
"Drug control law",
"Regulation of chemicals"
] |
71,292,210 | https://en.wikipedia.org/wiki/Amanita%20groenlandica | Amanita groenlandica is a species of fungus in the family Amanitaceae. It has been placed in Amanita sect. Vaginatae.
Taxonomy
Amanita groenlandica was classified by the mycologists Henning Knudsen and Torbjørn Borgen in 1987 after a previous classification by Dutch mycologist Cornelis Bas in 1977 failed to satisfy the rules for a valid publication.
Amanita groenlandica f. alpina is the alpine form of this species found in the Rocky Mountains of North America classified by the mycologists C.L. Cripps and Karl E. Horak in 2010. It is considered a synonym of A. groenlandica.
Description
A. groenlandica is a large Amanita mushroom with white flesh.
Cap: at the extreme but more commonly in the range of 5–9 cm. Initially hemispheric expanding to convex with a broad umbo which declines or disappears as the cap flattens with age. Pale straw or greyish yellow in colour when young with a bright yellow to brown colour developing as it ages. Patches of the universal veil or volva often remain like scales on the cap. Stem: 4–15 cm in height with a thickness of 0.8–2 cm tapering to up to 3.3 cm at the base. White to pale brown or grey in colour. Ringless with a fragile grey or ochre volva. Gills: Free. Initially white with a pale cream colour developing with age. Spore print: White. Spores: Globose or subglobose, hyaline and nonamyloid. 9.6–12.8 μm diameter. Taste: Indistinct. Smell: Indistinct.
Amanita groenlandica f. alpina is described as being similar to A. groenlandica only taller and with a different colouration that tends to more pale orange-brown colours in the cap, which is also described as being less viscid. The universal veil is described as sometimes being more creamy in colour rather than possessing the grey tones of A. groenlandica. Unlike A. groenlandica which is described as odorless f. alpina is said to have a fruity smell when young which becomes unpleasant with age.
Distribution and habitat
A. groenlandica is an arctic species described from Greenland where it is the most common species of Amanita. It is found growing in small groups or as a solitary mushroom under willow and birch trees. Found from July to September but most commonly in August.
In 2022 the fungus was documented in the Cairngorms mountains of Scotland based on DNA analysis performed on soil samples.
Amanita groenlandica f. alpina has been documented from the Rocky Mountains of North America where it was observed growing with willow trees. It fruits July through August on the Beartooth and Hellroaring Plateaus at an elevation of 3,100-3,400 metres above sea level.
References
groenlandica
Fungi described in 1987
Fungi of Greenland
Fungus species | Amanita groenlandica | [
"Biology"
] | 652 | [
"Fungi",
"Fungus species"
] |
71,292,841 | https://en.wikipedia.org/wiki/VZ%20Piscium | VZ Piscium is a triple star system in the equatorial constellation of Pisces. it is located at a distance of 178 light years from the Sun based on parallax measurements, and has an apparent visual magnitude of about 10.3. This is an eclipsing binary system that undergoes shallow eclipses; the brightness decreases to magnitude 10.45 during the primary eclipse, then to magnitude 10.43 with the secondary eclipse, although as a contact binary the brightness varies continuously with no period of constant maximum brightness. The system is drifting closer with a radial velocity of approximately −4 km/s, and has a net heliocentric velocity of 144.1 km/s.
S. C. Wolff and associates examined the spectrum of this star in 1965 and found very weak H and K lines with an emission component. Some of the lines are doubled, which suggested this is a contact binary. It was confirmed as a W Ursae Majoris (W UMa) variable using photometric observations made by J. Moorhead. O. J. Eggen in 1967 found a period of just and a high tangential space velocity of at least 100 km/s. Most of the variability of the system was found to be ellipsoidal and a small O'Connell effect was detected. The combined stellar class of the system matches a K-type main-sequence star with a type of about K3. A mass ratio close to one indicates the two stars have similar mass.
Due to physical contact, most W UMa-type variables show eclipse minima of almost equal depth, but that is not the case for VZ Psc. The H and K line emission for this system suggests surface magnetic activity, and thus star spots. These darker features may explain the varying light curve of the system. A variation in the orbital period of the system has been observed over a time frame of 25 years, which may be explained by a magnetic activity cycle of the lower mass component. There is a temperature difference of about 900 K between the two components, which remains unexplained as direct contact would tend to even out the temperature. Both stars are highly distorted by the gravity of the other star. The more massive star is a third larger in the direction of the companion than pole-to-pole, and the less massive star is even more distorted.
The outer (tertiary) companion, named HIP 115819 B, was detected as a member of this system in 2014 using data from the Pan-STARRS. It is located at a projected separation of from the inner pair. It is a very low-mass star with 7.9–8.5% the mass of the Sun and a spectral type M9. This star has a cool effective temperature of and 1.06 times the radius of Jupiter (~0.11 times the radius of the Sun).
References
Further reading
K-type main-sequence stars
W Ursae Majoris variables
Spectroscopic binaries
Pisces (constellation)
Durchmusterung objects
115819
Piscium, VZ | VZ Piscium | [
"Astronomy"
] | 627 | [
"Pisces (constellation)",
"Constellations"
] |
71,293,099 | https://en.wikipedia.org/wiki/Daniel%20B.%20Szyld | Daniel B. Szyld (born 1955 in Buenos Aires) is an Argentinian and American mathematician who is a professor at Temple University in Philadelphia. He has made contributions to numerical and applied linear algebra as well as matrix theory.
Education
He was admitted without an undergraduate degree to the graduate school at New York University, where he defended his PhD in 1983. While there, he worked as a research assistant for Wassily Leontief.
International awards and appointments
He was named as a SIAM Fellow and as a fellow of the American Mathematical Society in 2017. In 2020, he was elected president of the International Linear Algebra Society. He was editor-in-chief for the Electronic Transactions on Numerical Analysis from 2005 to 2013 and SIAM Journal on Matrix Analysis and Applications from 2015 to 2020 and is on the editorial boards of several journals, including the Electronic Journal of Linear Algebra (ELA), the Electronic Transactions on Numerical Analysis (ETNA), Linear Algebra and its Applications, Mathematics of Computation, Numerical Linear Algebra with Applications, and Journal of Numerical Analysis and Approximation Theory. A conference in honor of his 65th birthday was held in 2022
Books and edited proceedings
Selected papers
References
1955 births
Living people
Fellows of the Society for Industrial and Applied Mathematics
Argentine emigrants to the United States
Fellows of the American Mathematical Society
Temple University faculty
20th-century Argentine mathematicians
21st-century Argentine mathematicians
Algebraists
21st-century American mathematicians
Courant Institute of Mathematical Sciences alumni
20th-century American mathematicians
Scientists from Buenos Aires | Daniel B. Szyld | [
"Mathematics"
] | 298 | [
"Algebra",
"Algebraists"
] |
71,293,530 | https://en.wikipedia.org/wiki/Natrinema%20thermotolerans | Natrinema thermotolerans is a species of archaea in the family Natrialbaceae.
References
Halobacteria
Archaea described in 2000 | Natrinema thermotolerans | [
"Biology"
] | 34 | [
"Archaea",
"Archaea stubs"
] |
71,293,548 | https://en.wikipedia.org/wiki/Natrinema%20saccharevitans | Natrinema saccharevitans is a species of archaea in the family Natrialbaceae.
References
Halobacteria
Archaea described in 2005 | Natrinema saccharevitans | [
"Biology"
] | 34 | [
"Archaea",
"Archaea stubs"
] |
71,293,588 | https://en.wikipedia.org/wiki/Natrinema%20limicola | Natrinema limicola is a species of archaea in the family Natrialbaceae.
References
Halobacteria
Archaea described in 2006 | Natrinema limicola | [
"Biology"
] | 32 | [
"Archaea",
"Archaea stubs"
] |
71,293,599 | https://en.wikipedia.org/wiki/Natrinema%20hispanicum | Natrinema hispanicum is a species of archaea in the family Natrialbaceae.
References
Halobacteria
Archaea described in 2007 | Natrinema hispanicum | [
"Biology"
] | 31 | [
"Archaea",
"Archaea stubs"
] |
71,293,652 | https://en.wikipedia.org/wiki/Kazumi%20Maki | Kazumi Maki (kanji: 真木 和美, kana: まき かずみ Maki Kazumi, January 27, 1936, Takamatsu, Japan – September 10, 2008, Los Angeles) was a Japanese theoretical physicist, known for his research in "superconductivity, superfluid ³He, and quasi‑one‑dimensional (1D) materials."
Biography
Kazumi Maki spent most of his childhood in Kyoto. During WW II he with his family moved to a rural area because of a scarcity of food and the danger of aerial attack. At Kyoto University he received his Ph.D. in 1964 with a thesis on theoretical particle physics, written under the supervision of Hideki Yukawa. Maki was a postdoc at the University of Chicago for the academic year 1964–1965 and an assistant professor from 1965 to 1967 at the University of California, San Diego. From 1967 to 1974 he was a professor at
Tohoku University. From 1974 until his death in 2008 he was a professor at the University of Southern California (USC). For the academic year 1979–1980 he was a Guggenheim Fellow; during this time he worked with Hagen Kleinert.
Maki was the author or co-author of approximately 500 scientific publications. In the 1960s and early 1970s his research dealt with BCS theory. In 1968 he published his theoretical analysis predicting an anomalous increase in electrical conductivity caused by superconducting fluctuations just above the critical temperature for a low-temperature superconductor. This predicted increase in conductivity is empirically valid, and the corresponding term in perturbation theory is now called the "Maki-Thompson term." Maki also did research on pair breaking of Cooper pairs and the accompanying gapless (zero gap) superconductivity, in which there is s-wave superconductivity in the presence of impurities, causing a range of temperatures where the energy gap vanishes. He contributed an important review paper Gapless Superconductivity to volume 2 of the classic 2-volume Superconductivity edited by Ronald D. Parks and published by Marcel Dekker in 1969.
From the early 1970s until 1990, Maki investigated superfluid ³He and quasi-one-dimensional materials.
From 1991 until the end of his life, he worked on high-temperature superconductors and investigated the effects of anisotropic ordering parameters on the transport and magnetic properties both in the superconducting state and in the pseudo-gap phase. He saw the pseudo-gap phase as a kind of unconventional spin-density wave. As evidence accumulated for d-wave pairing in high-temperature copper oxide superconductors, he pointed out the much greater susceptibility of d-waves to pair breakage from non-magnetic impurities because, unlike conventional s-wave superconductivity, they have topologically protected nodes. He pursued the idea of gossamer superconductivity (d-wave superconductivity in the presence of d-density waves) and half-integer flux quanta in unconventional superconductors.
Kazumi Maki was elected in 1981 a fellow of the American Physical Society. He received in 1972 the Nishina Memorial Prize and in 2006, from the University of Illinois Urbana-Champaign (UIUC), the with citation "for his work on gapless quasiparticle excitations due to pair-breaking and for elucidating the role of fluctuations".
His doctoral students include Robijn Bruinsma and Dieter Vollhardt.
He and his wife, Masako, were aficionados of the Los Angeles Music Center. At their home they frequently played duets — Kazumi's violin and Masako's piano. Upon his death he was survived by his widow.
References
1936 births
2008 deaths
20th-century Japanese physicists
21st-century Japanese physicists
Kyoto University alumni
Academic staff of Tohoku University
University of Southern California faculty
Fellows of the American Physical Society
Condensed matter physicists | Kazumi Maki | [
"Physics",
"Materials_science"
] | 830 | [
"Condensed matter physicists",
"Condensed matter physics"
] |
71,295,003 | https://en.wikipedia.org/wiki/Bryostigma%20epiphyscium | Bryostigma epiphyscium is a species of lichenicolous fungus in the order Arthoniales. Formerly classified in the genera Arthonia and Conida, it was transferred to the genus Bryostigma in 2020.
It is known to infect the lichen Physcia caesia and other lichens of the genus Physcia.
References
Arthoniomycetes
Fungi of Iceland
Fungi described in 1875
Taxa named by William Nylander (botanist)
Lichenicolous fungi
Fungus species | Bryostigma epiphyscium | [
"Biology"
] | 111 | [
"Fungi",
"Fungus species"
] |
71,295,015 | https://en.wikipedia.org/wiki/International%20Girls%20in%20ICT%20Day | The International Girls in ICT Day is celebrated on the fourth Thursday in April to create awareness on the need for more girls and women in the information and communications technology (ICT) sector.
Background
The day is an initiative of the Plenipotentiary Resolution 70 (Rev. Busan, 2014) by the Member States of the International Telecommunication Union to create programs that encourage girls and young women to consider studies and careers in information and communication technologies.
In 2022, the African Development Bank's Coding for Employment program set aside half its training slots for women applicants to commemorate International Girls in ICT Day.
Participation
In 2015, annual Girls in ICT Day events recorded about 177,000 girls around the world through over 5,300 events in more than 150 countries. By 2022, International Telecommunication Union data showed that more than 3,62,000 girls and young women have celebrated more than 11,000 celebrations in 171 countries worldwide during the International Girls in ICT Day.
References
See also
International Day of the Girl Child
International Telecommunication Union
Civil awareness days
Feminist events
Recurring events established in 2014
April observances
Women in technology | International Girls in ICT Day | [
"Technology"
] | 222 | [
"Women in technology",
"Women in science and technology"
] |
71,295,111 | https://en.wikipedia.org/wiki/Arthonia%20stereocaulina | Arthonia stereocaulina is a species of lichenicolous fungus in the family Arthoniaceae.
Distribution
Arthonia stereocaulina has been reported from Alaska, Canada, Iceland, Russia and Svalbard.
Host species
As the name suggests, Arthonia stereocaulina infects lichens of the genus Stereocaulon. Known host species are:
Stereocaulon alpinum
Stereocaulon arcticum
Stereocaulon botryosum
Stereocaulon capitellatum
Stereocaulon depressum
Stereocaulon glareosum
Stereocaulon groenlandicum
Stereocaulon intermedium
Stereocaulon myriocarpum
Stereocaulon paschale
Stereocaulon rivulorum
Stereocaulon saxatile
Stereocaulon tomentosum
References
Arthoniaceae
Fungi of Canada
Fungi of Iceland
Fungi of Russia
Fungi of Svalbard
Fungi of the United States
Fungi described in 1993
Taxa named by Rolf Santesson
Lichenicolous fungi
Fungus species | Arthonia stereocaulina | [
"Biology"
] | 220 | [
"Fungi",
"Fungus species"
] |
71,295,296 | https://en.wikipedia.org/wiki/Cercidospora%20soror | Cercidospora soror is a species of lichenicolous fungus in the genus Cercidospora but it has not been assigned to a family. It was discovered growing on Arthrorhaphis citrinella in Austria but has since then also been reported from Greenland, where it infects Arthrorhaphis alpina and Arthrorhaphis citrinella.
References
Dothideomycetes
Fungi described in 1995
Fungi of Austria
Fungi of Greenland
Lichenicolous fungi
Taxa named by Dagmar Triebel
Taxa named by Walter Obermayer
Fungus species | Cercidospora soror | [
"Biology"
] | 127 | [
"Fungi",
"Fungus species"
] |
71,295,422 | https://en.wikipedia.org/wiki/Muellerella%20antarctica | Muellerella antarctica is a species of lichenicolous fungus in the family Verrucariaceae. It was discovered in 2008 on Isla Navarino in Chile where it parasitised Hypogymnia antarctica.
References
Verrucariales
Fungi described in 2008
Fungi of Chile
Lichenicolous fungi
Taxa named by Javier Angel Etayo Salazar
Fungus species | Muellerella antarctica | [
"Biology"
] | 75 | [
"Fungi",
"Fungus species"
] |
71,295,844 | https://en.wikipedia.org/wiki/Capacitated%20arc%20routing%20problem | In mathematics, the capacitated arc routing problem (CARP) is that of finding the shortest tour with a minimum graph/travel distance of a mixed graph with undirected edges and directed arcs given capacity constraints for objects that move along the graph that represent snow-plowers, street sweeping machines, or winter gritters, or other real-world objects with capacity constraints. The constraint can be imposed for the length of time the vehicle is away from the central depot, or a total distance traveled, or a combination of the two with different weighting factors.
There are many different variations of the CARP described in the book Arc Routing:Problems, Methods, and Applications by Ángel Corberán and Gilbert Laporte.
Solving the CARP involves the study of graph theory, arc routing, operations research, and geographical routing algorithms to find the shortest path efficiently.
The CARP is NP-hard arc routing problem.
The CARP can be solved with combinatorial optimization including convex hulls.
The large-scale capacitated arc routing problem (LSCARP) is a variant of the capacitated arc routing problem that applies to hundreds of edges and nodes to realistically simulate and model large complex environments.
References
Graph theory | Capacitated arc routing problem | [
"Mathematics"
] | 246 | [
"Discrete mathematics",
"Mathematical relations",
"Graph theory",
"Combinatorics"
] |
71,297,236 | https://en.wikipedia.org/wiki/Xerox%20Dover | The Xerox Dover laser printer was an early laser printer manufactured at Xerox PARC in the late 1970s. Around 35 were built. It was a successor to the EARS printer, itself a successor to the Xerox Graphics Printer.
The Dover was developed by Gary Starkweather. The printer was based on a stripped down Xerox 7000 reduction duplicator chassis.
Dover printers were in use at several high-profile computer science research labs. A Dover printer was installed at Stanford University's computer science department in 1980, and a Dover printer was available at the MIT AI Lab in 1982, hosted by a Xerox Alto computer.
References
Laser printers
1970s in computing | Xerox Dover | [
"Technology"
] | 139 | [
"Computing stubs"
] |
71,299,772 | https://en.wikipedia.org/wiki/Natronolimnohabitans | Natronolimnohabitans is a genus of the Natrialbaceae. It has also been proposed that Haloterrigena turkmenica be considered a part of these genus.
Taxonomy
The type species of Natronolimnohabitans, N. innermongolicus, was originally described as one of two original members in the genus Natronolimnobius.
See also
List of Archaea genera
References
Archaea genera
Taxa described in 2020
Euryarchaeota | Natronolimnohabitans | [
"Biology"
] | 102 | [
"Archaea",
"Archaea stubs"
] |
71,300,074 | https://en.wikipedia.org/wiki/Haloarchaeobius | Haloarchaeobius (common abbreviation Hab.) is a genus of halophilic archaea in the family of Halobacteriaceae.
Phylogeny
The currently accepted taxonomy is based on the List of Prokaryotic names with Standing in Nomenclature (LPSN) and National Center for Biotechnology Information (NCBI).
See also
List of Archaea genera
References
Archaea genera
Taxa described in 2012
Euryarchaeota | Haloarchaeobius | [
"Biology"
] | 91 | [
"Archaea",
"Archaea stubs"
] |
71,300,082 | https://en.wikipedia.org/wiki/Halapricum | Halapricum (common abbreviation Hpr.) is a genus of halophilic archaea in the family of Haloarculaceae.
Phylogeny
The currently accepted taxonomy is based on the List of Prokaryotic names with Standing in Nomenclature (LPSN) and National Center for Biotechnology Information (NCBI).
See also
List of Archaea genera
References
External links
Archaea genera
Taxa described in 2014
Euryarchaeota | Halapricum | [
"Biology"
] | 92 | [
"Archaea",
"Archaea stubs"
] |
71,300,141 | https://en.wikipedia.org/wiki/Inception%20score | The Inception Score (IS) is an algorithm used to assess the quality of images created by a generative image model such as a generative adversarial network (GAN). The score is calculated based on the output of a separate, pretrained Inception v3 image classification model applied to a sample of (typically around 30,000) images generated by the generative model. The Inception Score is maximized when the following conditions are true:
The entropy of the distribution of labels predicted by the Inceptionv3 model for the generated images is minimized. In other words, the classification model confidently predicts a single label for each image. Intuitively, this corresponds to the desideratum of generated images being "sharp" or "distinct".
The predictions of the classification model are evenly distributed across all possible labels. This corresponds to the desideratum that the output of the generative model is "diverse".
It has been somewhat superseded by the related Fréchet inception distance. While the Inception Score only evaluates the distribution of generated images, the FID compares the distribution of generated images with the distribution of a set of real images ("ground truth").
Definition
Let there be two spaces, the space of images and the space of labels . The space of labels is finite.
Let be a probability distribution over that we wish to judge.
Let a discriminator be a function of type where is the set of all probability distributions on . For any image , and any label , let be the probability that image has label , according to the discriminator. It is usually implemented as an Inception-v3 network trained on ImageNet.
The Inception Score of relative to isEquivalent rewrites include is nonnegative by Jensen's inequality.
Pseudocode:
Interpretation
A higher inception score is interpreted as "better", as it means that is a "sharp and distinct" collection of pictures.
, where is the total number of possible labels.
iff for almost all That means is completely "indistinct". That is, for any image sampled from , discriminator returns exactly the same label predictions .
The highest inception score is achieved if and only if the two conditions are both true:
For almost all , the distribution is concentrated on one label. That is, . That is, every image sampled from is exactly classified by the discriminator.
For every label , the proportion of generated images labelled as is exactly . That is, the generated images are equally distributed over all labels.
References
Machine learning
Computer graphics | Inception score | [
"Engineering"
] | 518 | [
"Artificial intelligence engineering",
"Machine learning"
] |
71,300,215 | https://en.wikipedia.org/wiki/Halostella | Halostella (common abbreviation Hsl.) is a genus of halophilic archaea in the family of Halobacteriaceae.
Phylogeny
The currently accepted taxonomy is based on the List of Prokaryotic names with Standing in Nomenclature (LPSN) and National Center for Biotechnology Information (NCBI).
See also
List of Archaea genera
References
External links
Archaea genera
Taxa described in 2016
Halobacteria | Halostella | [
"Biology"
] | 90 | [
"Archaea",
"Archaea stubs"
] |
71,300,284 | https://en.wikipedia.org/wiki/World%20Backup%20Day | World Backup Day is a commemorative date celebrated annually by the backup industry and tech industry all over the world on March 31. It highlights the importance of protecting data and keeping systems and computers secure.
World Backup Day started with a post on Reddit where a user wrote about losing their hard drive and wishing someone had reminded them about how important it is to backup data. The campaign started by Ismail Jadun in 2011 and every year news outlets write articles about the importance of backing up data on World Backup Day.
Observance
Every year on March 31, companies tweet and have podcasts about the importance of backing up data to prevent data loss. On the website WorldBackupDay.com people can make a pledge in ten languages on various social media channels about the importance of backing up their data. The World Backup Day is recognized as National Calendar Day on many national holiday websites.
References
External links
Official site
Backup
Awareness days
Unofficial observances | World Backup Day | [
"Engineering"
] | 190 | [
"Reliability engineering",
"Backup"
] |
71,301,382 | https://en.wikipedia.org/wiki/Muellerella%20hospitans | Muellerella hospitans is a species of lichenicolous fungus in the family Verrucariaceae. It is known to infect the lichen Bacidia rubella.
References
Verrucariales
Fungi described in 1863
Lichenicolous fungi
Taxa named by Ernst Stizenberger
Fungus species | Muellerella hospitans | [
"Biology"
] | 65 | [
"Fungi",
"Fungus species"
] |
71,301,813 | https://en.wikipedia.org/wiki/Halohasta | Halohasta (common abbreviation Hht.) is a genus of halophilic archaea in the family of Halorubraceae.
Phylogeny
The currently accepted taxonomy is based on the List of Prokaryotic names with Standing in Nomenclature (LPSN) and National Center for Biotechnology Information (NCBI).
See also
List of Archaea genera
References
Archaea genera
Taxa described in 2013
Euryarchaeota | Halohasta | [
"Biology"
] | 89 | [
"Archaea",
"Archaea stubs"
] |
71,301,862 | https://en.wikipedia.org/wiki/Haloparvum | Haloparvum (common abbreviation Hpv.) is a genus of halophilic archaea in the family of Haloferacaceae.
See also
List of Archaea genera
References
Archaea genera
Taxa described in 2016
Euryarchaeota | Haloparvum | [
"Biology"
] | 51 | [
"Archaea",
"Archaea stubs"
] |
71,302,170 | https://en.wikipedia.org/wiki/Muellerella%20lecanactidis | Muellerella lecanactidis is a species of lichenicolous (lichen-dwelling) fungus in the family Verrucariaceae. It was formally described as a new species in 2003 by Paul Diederich and Pieter van den Boom, from specimens collected in California. The authors thought that the type specimen was parasitising a lichen from genus Lecanactis, hence the species epithet, but it was later discovered that the host was actually Sigridea californica.
References
Verrucariales
Fungi described in 2003
Fungi of the United States
Lichenicolous fungi
Taxa named by Paul Diederich
Fungus species | Muellerella lecanactidis | [
"Biology"
] | 134 | [
"Fungi",
"Fungus species"
] |
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