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61,980,431 | https://en.wikipedia.org/wiki/Wasabi%20receptor%20toxin | Wasabi receptor toxin (WaTx) is the active component of the venom of the Australian black rock scorpion Urodacus manicatus. WaTx targets TRPA1, also known as the wasabi receptor or irritant receptor. WaTx is a cell-penetrating toxin that stabilizes the TRPA1 channel open state while reducing its Ca2+-permeability, thereby eliciting pain and pain hypersensitivity without the neurogenic inflammation that typically occurs in other animal toxins.
Etymology
This scorpion toxin was named WaTx because it targets TRPA1 in a similar fashion as plant-derived irritants, such as mustard oil and wasabi. These irritants activate the TRPA1 channel in peripheral primary afferent sensory neurons, subsequently eliciting their pungent taste as well as sinus clearing and eye stinging.
Sources
WaTx originates from the venom of the Australian Black Rock Scorpion (Urodacus manicatus).
Chemistry
Family
WaTx belongs to the κ-KTx family, as it shows similarities in the disulfide bonding pattern. The KTx family is classified into four subfamilies: α-, β-, γ-, and κ-KTx. Unlike other KTx subfamilies, κ-KTx scorpion toxins form cysteine-stabilized α-helical hairpins (Cs α/α), whereas κ-KTx spider and crab toxins form cysteine-stabilized antiparallel β-sheets (Cs β/β).
Structure
WaTx is a macromolecule with an estimated weight of 3.86 kDa, which consists of 33 amino-acid residues. Its amino-acid sequence is as follows:
The pattern of cysteine residues in the amino acid sequence, which is underlined above, indicates an independent Cys9-Cys27, Cys13-Cys23 disulfide bonding pattern. The two disulfide bridges connect two parallel α-helices with a β-turn. The disulfide bonding pattern stabilizes the rigid and compact helical hairpin structure at two points, contributing to the stable tertiary structure of the protein.
The hairpin contains four basic residues that enable passive diffusion across the membrane. Two features of the protein structure have been associated with cell-penetrating properties that are uncommon for peptide toxins. Firstly, a patch (or predominance) of basic residues is located at the open end of the hairpin, where the amino- and carboxy-terminal meet. Secondly, the amino-terminal in WaTx exhibits a dense dipole moment. Other proteins with the ability to penetrate the plasma membrane include HIV Tat and Drosophila penetratin. However, these proteins have no sequence resemblance to WaTx.
Homology
The amino-acid sequence of WaTx bears little resemblance to other peptides in terms of homology. Although the toxin was discovered to be cell-penetrating, there is no sequence similarity to classical cell-penetrating peptides (CPPs).
Target
WaTx targets TRPA1, one of about 30 transient receptor potential channels. WaTx is both potent and selective for TRPA1. Other known TRP-channels are not activated by the toxin. WaTx has an effect on human TRPA1 (hTRPA1), while it does not have an effect on to rat and snake TRPA1 (rsTRPA1).
Mode of action
WaTx penetrates the plasma membrane instead of following standard routes, subsequently accessing the inferior part of the cell. The basic residues and dipole moment on the helical hairpin structure enable the passive diffusion of WaTx.
Once the toxin arrives in the cell, it activates TRPA1 via an intracellular domain in the lower part of voltage-sensing segments S1-S4 called ‘the allosteric nexus’. The allosteric nexus is located at the region where the TRP-like domain, pre-S1 helix and cysteine-rich S4-S5 linker meet. This inner cavity is a common binding site to reactive electrophilic ligands—and now WaTx. This locus is a key regulatory site for stimulus integration and propagates conformational changes to the channel's gate. When activated, the open-state TRPA1 allows the flow of positively charged sodium and calcium ions into the cell.
Electrophilic ligands make covalent modifications to specific cysteine residues in the cytoplasmic amino-terminus that increase the probability of channel opening. Although both Na+ and Ca2+ can enter TRPA1, the channel normally has a preference towards Ca2+ and the intracellular calcium concentration increases more rapidly than the sodium concentration. WaTx interacts differently with the channel compared to reactive electrophiles. WaTx non-covalently binds to the allosteric nexus and initiates interactions with an integrated complex between the N-terminal cysteine-rich linker (S4-S5) and C-terminal TRP-like domains. This prevents the open channel from closing, as opposed to increasing the probability of opening, and results in a prolonged duration of the channel's open state. With WaTx bound in open state, TRPA1 lacks a preference for Ca2+ over Na+, which accounts for the lower calcium permeability. Consequently, both electrophilic ligands and WaTx trigger a pain response, but the calcium levels that result from WaTx are too low to initiate subsequent neuropeptide release and neurogenic inflammation. This suggests that WaTx may act only to open the ion permeation gate of TRPA1, without dilating the selectivity filter (dilation of the selectivity filter having been proposed to underlie enhanced calcium permeability of TRPA1 after activation by classical electrophilic irritants).
Toxicity
WaTx elicits acute thermal and mechanical hypersensitivity. This response has been proven phenotypically proven by injecting WaTx in the hind paw of mice, which leads to dose-dependent nocifensive behavior. However, WaTx does not cause the local edema that is typical for noxious electrophiles. This lack of swelling indicates that WaTx fails to promote the release of calcitonin gene-related peptide (CGRP)—a hallmark of neurogenic inflammation.
Treatment
There is no immediate danger after being stung by an Australian Black Rock Scorpion. The wound should be washed and cleaned, after which medical advice should be sought.
Therapeutic use
So far, there are no pharmacologicals based on (the mode of action of) WaTx. However, understanding the mechanisms of WaTx's interaction with TRPA1 may aid in the development of therapeutics targeting TRPA1, which is considered a promising target for treating pain, itch and neurogenic inflammation syndromes that involve nociception.
References
Ion channel toxins
Neurotoxins
Scorpion toxins | Wasabi receptor toxin | [
"Chemistry"
] | 1,447 | [
"Neurochemistry",
"Neurotoxins"
] |
61,980,776 | https://en.wikipedia.org/wiki/Trialen | Trialen was an explosive developed in Germany. It was used during World War II in the V-1 flying bomb and Arado E.377 glide bomb, among other weapons, as an enhanced blast explosive. Trialen was the German equivalent of the British explosive Torpex, though its production was hindered by a shortage of the aluminium powder that was added to increase its explosive power.
It comprised a mixture of TNT, hexogen, and aluminium powder in varying proportions for each of three versions, known as trialen (or filler) 105, 106 and 107 respectively. The proportions for each version were:
Trialen 105: trotyl 70%, hexogen 15%, aluminium powder 15%
Trialen 106: trotyl 50%, hexogen 25%, aluminium powder 25%
Trialen 107: trotyl 50%, hexogen 20%, aluminium powder 30%
Trialen 105/109: a mixture of 27% trialen 105 and 73% PMF 109. PMF 109 (Panzermunitionsfüllung 109) was a mixture consisting of 71% cyclonite, 25% aluminium powder and 4% montan wax. Though highly brisant and thermobaric, this mixture was infusible and quite impact sensitive, hence ill-suited for filling large caliber munitions. These drawbacks were overcome by the so-called Stuckfüllung, or "biscuit filling", method: the pulverulent PMF 109 mixture was compressed into small cylindrical, tablet-like pellets and these were poured into the munition body, the space between them being filled with molten fusible trialen 105; this method allowed the German munition factories to produce large, quasi homogeneous fillings containing a high proportion of cyclonite and hence high-energy output and brisance by a simple variant of the melt casting process, while simultaneously conserving the trotyl needed to do so.
References
Explosives | Trialen | [
"Chemistry"
] | 406 | [
"Explosives",
"Explosions"
] |
61,981,197 | https://en.wikipedia.org/wiki/IT%20cluster%20Rhine-Main-Neckar | The IT cluster Rhine-Main-Neckar, also known as Silicon Valley of Germany, is one of the most important locations of the IT and high-tech industry worldwide. It is concentrated in the Rhine-Main and Rhine-Neckar metropolitan regions. The IT cluster Rhine-Main-Neckar is the largest IT cluster in Europe. 50 percent of the worldwide revenue of the hundred largest European software companies is generated by companies in this region. The Rhine-Main-Neckar region also has one of the most important biopharmaceutical, fintech, finance and consulting clusters in Europe.
In addition to universities such as Technische Universität Darmstadt and University of Frankfurt and research institutions such as the German Research Center for Artificial Intelligence and ATHENE, software companies such as SAP SE, Software AG and T-Systems also have their headquarters in the region.
Importance in the world
In 2010, the French venture capital firm Truffle Capital published in its study "Truffle 100 European Clusters" that the Rhine-Main-Neckar region accounts for 50 percent of the worldwide revenue of the hundred largest European software providers. It compared the Rhine-Main-Neckar region as an IT cluster with Silicon Valley as the "Silicon Valley of Europe". According to this study, the Rhine-Main-Neckar IT cluster combined more than 12.5 billion euros in software-related sales in 2009. The next largest European IT cluster was Paris with 2.4 billion euros.
In a 2009 study, the region was compared with IT clusters such as Oulu (Finland), Bangalore (India) and Silicon Valley. In contrast to the Silicon Valley, the main business area of the companies in the region is enterprise software.
According to a study by the European Commission, Darmstadt has the best cluster among all EU regions in the emerging industries. Emerging industries means future technologies that the EU attaches particular importance to for growth in Europe. Darmstadt also has the best biopharmaceutical cluster in Europe. The Rhineland-Palatinate region, which partly belongs to the Rhine-Main-Neckar region, ranks second among the biopharmaceutical clusters.
The region is one of the most important locations for IT security research worldwide. Darmstadt has the renowned ATHENE, the national center for research in security and privacy in Germany and the largest research institute for IT security in Europe. According to an analysis by Startup Genome, a company specialising in the analysis of startup ecosystems, the Rhine-Main region is also home to one of the world's most important startup ecosystems in the field of IT security and fintech.
Importance in Germany
The IT cluster Rhein-Main-Neckar is part of the Spitzencluster Software-Cluster, which also includes other regions. In January 2010, the Software-Cluster won the German government's Spitzencluster competition, the equivalence to the German Universities Excellence Initiative for clusters. The cluster's goal is to enable the transformation of companies into digital companies. This cluster consists of the centers Darmstadt, Kaiserslautern, Karlsruhe, Saarbrücken and Walldorf. Since 2017, the German Federal Ministry of Education and Research has supported the cooperation between the German Research Center for Artificial Intelligence and the Technische Universität Darmstadt with companies and research institutions from Silicon Valley, Singapore and Bahia, Brazil.
In a competition, the Federal Association for Information Technology, Telecommunications and New Media awarded Darmstadt the title of Digital City in 2017. This victory is intended to turn Darmstadt into a digital model city. In 2016, the Federal Ministry of Finance decided to make the region around Darmstadt the pre-eminent hub for the digital transformation of the economy.
According to a study by the auditing firm Ernst & Young from 2018, 24% of all Fintechs in Germany have settled in the Rhine-Main-Neckar region, with Frankfurt being considered the centre. This makes the Rhine-Main-Neckar region one of the most important locations for the fintech industry in Germany.
According to a study from 2013, the Rhine-Main region has the best cluster in Germany in the financial and consulting industry.
According to the German Research Foundation (DFG), the Technische Universität Darmstadt (TU Darmstadt) is one of the best universities in Germany in terms of research in computer science and the University of Mainz in the natural sciences. According to the report of the German Research Foundation (DFG) from 2018, in the period under review from 2014 to 2016 the TU Darmstadt received the highest number of competitive grants in the field of computer science and the University of Mainz the highest number of competitive grants in the natural sciences. In a competitive selection process, the DFG selects the best research projects from researchers at universities and research institutes and finances them. The ranking is thus regarded as an indicator of the quality of research. In a nationwide competition by the Federal Ministry of Economics and Energy, the Technische Universität Darmstadt was honoured as founding university.
Resident universities
Technische Universität Darmstadt
University of Frankfurt
University of Mannheim
University of Mainz
University of Applied Sciences Mainz
Darmstadt University of Applied Sciences
Frankfurt University of Applied Sciences
RheinMain University of Applied Sciences
Technische Universität Kaiserslautern
University of Applied Sciences Worms
The Karlsruhe Institute of Technology is not located directly in the IT-Cluster Rhine-Main-Neckar, but is adjacent to it and has nevertheless contributed to its development.
Resident companies (selection)
SAP
Software AG
DE-CIX
Merck Group
Microsoft Germany
Oracle Germany
IBM Germany
Rakuten Kobo Inc. Germany
Nemetschek
Airbus
Opel
Accenture
Capgemini
Computer Sciences Corporation
Crytek
Fujitsu Semiconductor Europe
Isra Vision
Kalypso Media
MAXON
Schott AG
Singulus Technologies
T-Systems
Terma A/S
TrekStor
United Internet
Resident research institutes (selection)
German Research Centre for Artificial Intelligence
GSI Helmholtz Centre for Heavy Ion Research
European Space Operations Centre
European Organisation for the Exploitation of Meteorological Satellites
ATHENE
Center for IT Security, Privacy and Accountability
See also
Silicon Saxony
German Silicon Valley (disambiguation)
References
Information technology places
Rhine-Neckar
Industry in Germany
Economy of Hesse | IT cluster Rhine-Main-Neckar | [
"Technology"
] | 1,259 | [
"Information technology",
"Information technology places"
] |
61,981,734 | https://en.wikipedia.org/wiki/Germanium%28II%29%20dicationic%20complexes | Ge(II) dicationic complexes refer to coordination compounds of germanium with a +2 formal oxidation state, and a +2 charge on the overall complex. In some of these coordination complexes, the coordination is strongly ionic, localizing a +2 charge on Ge, while in others the bonding is more covalent, delocalizing the cationic charge away from Ge. Examples of dicationic Ge(II) complexes are much rarer than monocationic Ge(II) complexes, often requiring the use of bulky ligands to shield the germanium center. Dicationic complexes of Ge(II) have been isolated with bulky isocyanide and carbene ligands. Much more weakly coordinated Germanium (II) dications have been isolated as complexes with polyether ligands, such as crown ethers and [2.2.2]cryptand. Crown ethers and cryptands are typically known for their ability to bind metal cations, however these ligands have also been employed in stabilizing low-valent cations of heavier p-block elements. A Ge2+ ion's valence shell consists of a filled valence s orbital but empty valence p orbitals, giving rise to atypical bonding in these complexes. Germanium is a metalloid of the carbon group, typically forming compounds with mainly covalent bonding, contrasting with the dative bonding observed in these coordination complexes.
History
In 2007, a Ge(II) based dication was reported by Rupar, Staroverov, Ragogna and Baines in which a Ge(II) unit is coordinated by three bulky N-heterocyclic carbene ligands. Later in 2008, Rupar, Staroverov and Baines isolated a weakly coordinate Ge(II) dication using cryptand[2.2.2], also the first example of a non-metallic mononuclear dication complexed with a cryptand. In this report, a Ge(II) cation is encapsulated within [2.2.2]cryptand with two triflate counter ions. The crystal structure of this Ge cryptand[2.2.2] (CF3SO3)2 salt reveals a lack of coordination between the encapsulated Ge(II) cation and the triflate anions. Since these reports, similar cationic Ge(II) complexes have been prepared employing crown ethers, azamacrocycles, and bulky isocyanide ligands.
Synthesis
In the preparation of Ge(II) cationic complexes, triflate is often chosen as a counter anion as it is relatively weakly coordinating. GeCl2•dioxane is often used as a starting material, as it is a convenient source of Ge(II).
Ge(II) cryptand[2.2.2]
The Ge(II) cryptand[2.2.2] complex was prepared by the addition of cryptand to a solution of N-heterocyclic carbene stabilized GeCl(CF3SO3) in tetrahydrofuran. The products obtained from this reaction are summarized below. The germanium cryptand salt precipitated from solution as a white powder, and the identity was established using proton NMR and crystal X-ray diffraction. The carbene stabilized germanium chloride side products (structures given below) were identified in solution after the reaction.
Ge(II) crown ethers
Ge(II) cationic species have been isolated with several crown ether ligands, including [12]crown-4, [15]crown-5, and [18]crown-6. Rupar et al. reported the synthesis of various germanium crown ethers employing GeCl2•dioxane as the source of Ge(II). Trimethylsilyl trifluoromethanesulfonate (Me3SiOTf) was used to displace chloride ligands with a more weakly associating triflate ligand. The resulting germanium crown ether complexes can adopt different geometries and cation charges depending on the size of the crown ether and the nature of the anionic ligand, summarized in the figure below. Only the Ge complex with [12]crown-4 is able to fully exclude counter anions from coordinating to Ge to give a dicationic complex. The larger crown ethers do not form sandwich complexes with Ge, and leave room for an anion to associate with the encapsulated Ge. These complexes were characterized with NMR, X-ray crystallography, Raman spectroscopy, and mass spectrometry.
Ge(II) carbene complex
The Ge(II) carbene stabilized dication reported by Rupar et al. was prepared by treating GeCl2•dioxane with an N-heterocyclic carbene (1,3-diisopropyl-4,5-dimethylimidazol-2-ylidene) to give the GeCl2 carbene complex. Upon treatment with trimethylsilyl iodide and excess carbene, the dicationic complex consisting of three carbene ligands to one Ge atom was formed.
Ge(II) 2,6-dimethylphenyl isocyanide complex
A Ge(II) dication stabilized by 4 isocyanide ligands was prepared by mixing GeCl2•dioxane and 2,6-dimethylphenyl isocyanide in toluene (scheme given below). Three molecules of GeCl2 are required per four molecules of the isocyanide ligand, as the counter anion is GeCl3−. This complex was crystallized from toluene, and was characterized by X-ray crystallography and NMR spectroscopy.
Structure and bonding
The geometry of these Ge(II) complexes is not adequately described by VSEPR theory due to the nature of the lone pair on Ge(II). VSEPR theory is used to predict geometric distortions about atoms with nonbonding electrons (lone pairs), but in some cases heavier main group elements can violate VSEPR theory, displaying a stereochemically inactive or "spherically symmetric" lone pair, deemed the inert-pair effect. Ge(II) complexes can possess stereochemically active or inactive lone pairs, depending on the ligand. To further assess the nature of the electronic structure of Ge(II) dicationic complexes, natural bond orbital (NBO) computational analysis is often employed.
Cryptand and crown ethers
The bonding in such Ge(II) polyether complexes is believed to be mainly ionic in character, differing from the expected mainly covalent character typical of most germanium compounds. This lack of a covalent interaction is exemplified in the relatively long Ge-O distances observed in crystal structures of Ge crown ether and Ge cryptand complexes. Ge-O covalent single bonds are expected to be approximately 1.8 Å in length. The crystal structure of the Ge(II) cryptand[2.2.2] complex reveals a much longer Ge-O distance of 2.49 Å, similarly the Ge-O distances range from 2.38-2.49 Å in the Ge(II) ([12]crown-4)2 sandwich complex. For the Ge(II) cryptand[2.2.2] complex, NBO analysis reveals the Ge(II) cation does not participate in any covalent bonding and that the lone pair on the Ge(II) resides in a purely s orbital, indicating a stereochemically inactive lone pair. This lone pair orbital of Ge(II) within cryptand[2.2.2] is depicted to the right. In the Ge(II) crown ether complexes presented above, only the sandwich complex with [12]crown-4 clearly bears a stereochemically inactive lone pair, suggested by the high symmetry of the complex. The Ge(II) complexes with [15]crown-5, and [18]crown-6 show geometric distortions likely due to the activity of the Ge(II) lone pair.
Carbenes and isocyanides
The bonding in Ge(II) dications stabilized by carbenes and isocyanides is believed to be more covalent in nature compared with the bonding in the polyether complexes. Furthermore, the positive charge in these complexes can be quite delocalized.
In the Ge(II) carbene dication complex reported by Rupar et al., the Ge-C bonds are 2.07 Å in length, only marginally longer than expected Ge-C bond lengths. This suggests that the Ge-carbene interaction is not dative, but more covalent in nature. Limiting resonance forms for the Ge(II) carbene dication can be drawn (shown below), with the Ge(II) bearing the full +2 charge, or with the carbenes forming covalent bonds to the Ge center giving each ligand a +1 charge and the Ge a -1 charge. Natural population analysis, a computational technique associated with NBO assigns a charge of +0.64 to the Ge atom, indicating that charge delocalization is significant, and that the structure is best described as an intermediate between the two limiting representations. This compound adopts a pyramidal geometry, with a stereochemically active lone pair on Ge.
Similar to the Ge(II) carbene complex, the Ge-C bond lengths in the Ge(II) (2,6-dimethylphenyl isocyanide)3 structure range between 2.03-2.07 Å, typical for expected Ge-C bonds. The ligands adopt a distorted tetrahedral structure about the germanium center in the crystal structure. NBO analysis of the Ge(II) isocyanide dication reveals a partially filled Ge p orbital as a frontier orbital of this complex, depicted to the right. The nature of the frontier orbitals change upon consideration of the GeCl3− counter anions in the NBO analysis. The NBO analysis also reveals a charge of +0.74 on Ge, with some positive charge delocalized on the isocyanide ligands. Geometry optimizations for both singlet and triplet electron configurations were performed for this complex, and the singlet was found to be favored by 48.6 kcal/mol.
Reactivity
The weakly coordinated Ge(II) cations are Lewis acids. Due to this weak coordination, such Ge(II) crown ether complexes could be useful for the preparation of other germanium compounds. Bandyopadhyay et al. have investigated the reactivity of a GeOTf+ [15]crown-5 complex, and found that the weakly coordinating triflate could be exchanged for H2O or NH3. Addition of water to a solution of GeOTf+ [15]crown-5 in dichloromethane results in the formation of the dicationic water complex, as depicted in the figure below. This water adduct was isolated and the structure was determined by X-ray crystallography, making it the first characterized Ge(II)-water adduct. Further addition of bulk water to this complex results in decomposition.
Upon treatment with base, this water adduct [Ge[15]crown-5·OH2]2+can be deprotonated to give the hydroxide adduct [Ge[15]crown-5·OH]+. Upon deprotonation to give the hydroxide adduct, the Ge-O bond becomes shorter and stronger. NBO analysis identifies the H2O-Ge[15]crown-5 interaction as a donor-acceptor interaction, while the HO-Ge[15]crown-5 interaction is identified as a polar single bond. This reactivity presents a potential strategy for the preparation of new Ge complexes.
The empty p orbitals of Ge(II) dications make them potential π-acceptors for transition metal complexes. Intriguingly, dicationic Ge(II) complexes have been shown to act as ligands for Au(I) and Ag(I). Raut and Majumdar report the use of a bis(α-iminopyridine) ligand to prepare a Ge(II) dicationic complex that coordinates to the electron rich Au(I) or Ag(I) metal centers. The bonding in such complexes is best described by σ-donation of the Ge(II) lone pair to the transition metal, and π-back donation from the filled transition metal d orbitals to the vacant Ge(II) p orbitals. This unusual activity for Ge(II) is under investigation for possible applications in catalysis.
See also
Cryptand
Host–guest chemistry
Organogermanium compounds
References
Germanium(II) compounds
Coordination complexes | Germanium(II) dicationic complexes | [
"Chemistry"
] | 2,673 | [
"Coordination chemistry",
"Coordination complexes"
] |
61,982,153 | https://en.wikipedia.org/wiki/Magic%20state%20distillation | Magic state distillation is a method for creating more accurate quantum states from multiple noisy ones, which is important for building fault tolerant quantum computers. It has also been linked to quantum contextuality, a concept thought to contribute to quantum computers' power.
The technique was first proposed by Emanuel Knill in 2004,
and further analyzed by Sergey Bravyi and Alexei Kitaev the same year.
Thanks to the Gottesman–Knill theorem, it is known that some quantum operations (operations in the Clifford group) can be perfectly simulated in polynomial time on a classical computer. In order to achieve universal quantum computation, a quantum computer must be able to perform operations outside this set. Magic state distillation achieves this, in principle, by concentrating the usefulness of imperfect resources, represented by mixed states, into states that are conducive for performing operations that are difficult to simulate classically.
A variety of qubit magic state distillation routines and distillation routines for qubits with various advantages have been proposed.
Stabilizer formalism
The Clifford group consists of a set of -qubit operations generated by the gates (where H is Hadamard and S is ) called Clifford gates. The Clifford group generates stabilizer states which can be efficiently simulated classically, as shown by the Gottesman–Knill theorem. This set of gates with a non-Clifford operation is universal for quantum computation.
Magic states
Magic states are purified from copies of a mixed state . These states are typically provided via an ancilla to the circuit. A magic state for the rotation operator is where . A non-Clifford gate can be generated by combining (copies of) magic states with Clifford gates. Since a set of Clifford gates combined with a non-Clifford gate is universal for quantum computation, magic states combined with Clifford gates are also universal.
Purification algorithm for distilling |M〉
The first magic state distillation algorithm, invented by Sergey Bravyi and Alexei Kitaev, is as follows.
Input: Prepare 5 imperfect states.
Output: An almost pure state having a small error probability.
repeat
Apply the decoding operation of the five-qubit error correcting code and measure the syndrome.
If the measured syndrome is , the distillation attempt is successful.
else Get rid of the resulting state and restart the algorithm.
until The states have been distilled to the desired purity.
References
Quantum computing
Algorithms | Magic state distillation | [
"Mathematics"
] | 494 | [
"Applied mathematics",
"Algorithms",
"Mathematical logic"
] |
61,984,669 | https://en.wikipedia.org/wiki/Hibar%20Systems | Hibar Systems Ltd was a Canadian manufacturer of automated, precision liquid dispensing and filling systems.
Hibar was started in 1974 when German-born Canadian engineer Heinz Barall developed a prototype of a precision metering pump that would dispense a small, precise amount (two microlitres) of electrolytes into button cell batteries. Barall took his prototype to one of the world's largest battery companies, where representatives were so impressed with its flawless performance, they kept the prototype and ordered more.
Building on its success in the battery industry, over the next 40 years, Hibar started building precision liquid dispensing systems for other industries, such as filling printer ink cartridges, putting pharmaceuticals into vials, and packaging cosmetics. The company also continued to supply its products to the battery production industry and developed new vacuum filling systems for lithium-ion battery applications.
Hibar's technology caught the eye of Tesla, Inc., which builds battery-electric vehicles and battery energy systems. Tesla quietly acquired Hibar sometime in 2019, which was first revealed in an October 2019 filing with the Canadian government.
The purchase came amid an acquisition spree where Tesla bought six other small companies with expertise in automation or battery technology.
Tesla merged the company into its operation, removing the Hibar signage from in front of the Richmond Hill office building in 2020 and changing the legal name on Hibar's website to Tesla Toronto Automation ULC in 2021.
References
Industrial machine manufacturers
Pump manufacturers
Canadian companies established in 1974
Manufacturing companies established in 1974
2019 mergers and acquisitions
Tesla, Inc.
Companies based in Richmond Hill, Ontario
Canadian brands | Hibar Systems | [
"Engineering"
] | 327 | [
"Industrial machine manufacturers",
"Industrial machinery"
] |
61,984,823 | https://en.wikipedia.org/wiki/Gra%C5%BEvydas%20Lukinavi%C4%8Dius | Gražvydas Lukinavičius is a Lithuanian biochemist. His scientific interest and main area of research is focused on labeling of biomolecules and visualization using super-resolution microscopy. He is co-invertor of DNA labeling technology known as Methyltransferase-Directed Transfer of Activated Groups (mTAG) and biocompatible and cell permeable fluorophore – silicon-rhodamine (SiR). Both inventions were commercialized. He is studying labeling methods and apply them for chromatin dynamics visualization in living cells.
Early life
He was born in the family of an electrician and a land development specialist. Lukinavičius finished secondary school in Jurbarkas.
Research
Lukinavičius completed his bachelor's degree and master's degree in biochemistry at the Vilnius University in 2000 and 2002 respectively. During this period he worked as a research assistant in Saulius Klimašauskas group and investigating conformational movements of the catalytic loop of DNA methyltransferase.
Later he became interested in S-Adenosyl methionine analogues which can be cofactors for methyltransferases. He collaborated with Elmar Weinhold from RWTH Aachen University and learned chemical synthesis and received his PhD in biochemistry at Vilnius University, Lithuania in September 2007. This led to the development of a new DNA labeling method, the Methyltransferase-Directed Transfer of Activated Groups (mTAG). This method was applied for optical DNA mapping and for a profiling epigenetic modifications by several research groups.
After obtaining his PhD, he moved to École polytechnique fédérale de Lausanne for postdoctoral research where he continued on working with protein labeling methods in group of Kai Johnsson. He improved SNAP-tag protein labelling technology by developing a new biocompatible fluorophore, silicon-rhodamine (SiR). During this period, he began a collaboration with Stefan Hell to perform one of the first super-resolution microscopy experiments of living cells.
In 2016, Stefan Hell invited Lukinavičius to the Department of NanoBiophotonics of the Max Planck Institute for Biophysical Chemistry in Göttingen. He has continued working on fluorescence labeling of biomolecules and started a Chromatin Labeling and Imaging group in 2018.
Memberships
Member of the Lithuanian Biochemical Society (since 2003)
Member of the Royal Society of Chemistry (since 2016)
Member of the International Chemical Biology Society (since 2017)
Member of the American Chemical Society (since 2021)
Member of the Sigma Xi (since 2023)
Publications
His most-cited publications, according to Google Scholar are:
Lukinavičius, G., K. Umezawa, N. Olivier, A. Honigmann, G. Yang, T. Plass, V. Mueller, L. Reymond, I. R. Corrêa, Z.-G. Luo, C. Schultz, E. A. Lemke, P. Heppenstall, C. Eggeling, S. Manley and K. Johnsson (2013). A near-infrared fluorophore for live-cell super-resolution microscopy of cellular proteins. Nature Chemistry 5(2): 132-139. (cited 837 times)
Lukinavičius, G., L. Reymond, E. D’Este, A. Masharina, F. Göttfert, H. Ta, A. Güther, M. Fournier, S. Rizzo, H. Waldmann, C. Blaukopf, C. Sommer, D. W. Gerlich, H.-D. Arndt, S. W. Hell and K. Johnsson (2014). Fluorogenic probes for live-cell imaging of the cytoskeleton. Nature Methods 11(7):731-3. (cited 817 times)
Dalhoff C., G. Lukinavičius, S. Klimašauskas and E. Weinhold (2006). Direct transfer of extended groups from synthetic cofactors by DNA methyltransferases. Nature Chemical Biology 2, 31-2. (cited 252 times)
Lukinavičius, G., C. Blaukopf, E. Pershagen, A. Schena, L. Reymond, E. Derivery, M. Gonzalez-Gaitan, E. D’Este, S. W. Hell, D. W. Gerlich and Kai Johnsson (2015). SiR–Hoechst is a far-red DNA stain for live-cell nanoscopy. Nature Communications 6, 8497. (Cited 276 times)
Liutkevičiūtė, Z., G. Lukinavičius, V. Masevičius, D. Daujotytė and S. Klimašauskas (2009). Cytosine-5-methyltransferases add aldehydes to DNA. Nature Chemical Biology 5, 400-402. (cited 173 times)
References
People from Jurbarkas
Biochemists
Lithuanian scientists
Vilnius University alumni
Living people
Year of birth missing (living people) | Gražvydas Lukinavičius | [
"Chemistry",
"Biology"
] | 1,079 | [
"Biochemistry",
"Biochemists"
] |
61,985,190 | https://en.wikipedia.org/wiki/Graph%20Query%20Language | GQL (Graph Query Language) is a standardized query language for property graphs first described in ISO/IEC 39075, released in April 2024 by ISO/IEC.
History
The GQL project is the culmination of converging initiatives dating back to 2016, particularly a private proposal from Neo4j to other database vendors in July 2016, and a proposal from Oracle technical staff within the ISO/IEC JTC 1 standards process later that year.
2019 GQL project proposal
In September 2019 a proposal for a project to create a new standard graph query language (ISO/IEC 39075 Information Technology — Database Languages — GQL) was approved by a vote of national standards bodies which are members of ISO/IEC Joint Technical Committee 1(ISO/IEC JTC 1). JTC 1 is responsible for international Information Technology standards. GQL is intended to be a declarative database query language, like SQL.
The 2019 GQL project proposal states:
Official ISO standard
The GQL standard, ISO/IEC 39075:2024 Information technology – Database languages – GQL, was officially published by ISO on
12 April 2024.
GQL project organisation
The GQL project is led by Stefan Plantikow (who was the first lead engineer of Neo4j's Cypher for Apache Spark project) and Stephen Cannan (Technical Corrigenda editor of SQL). They are also the editors of the initial early working drafts of the GQL specification.
As originally motivated, the GQL project aims to complement the work of creating an implementable normative natural-language specification with supportive community efforts that enable contributions from those who are unable or uninterested in taking part in the formal process of defining a JTC 1 International Standard. In July 2019 the Linked Data Benchmark Council (LDBC) agreed to become the umbrella organization for the efforts of community technical working groups. The Existing Languages and the Property Graph Schema working groups formed in late 2018 and early 2019 respectively. A working group to define formal denotational semantics for GQL was proposed at the third GQL Community Update in October 2019.
ISO/IEC JTC 1/SC 32 WG3
Seven national standards bodies (those of the United States, China, Korea, the Netherlands, the United Kingdom, Denmark and Sweden) have nominated national subject-matter experts to work on the project, which is conducted by Working Group 3 (Database Languages) of ISO/IEC JTC 1's Subcommittee 32 (Data Management and Interchange), usually abbreviated as ISO/IEC JTC 1/SC 32 WG3, or just WG3 for short. WG3 (and its direct predecessor committees within JTC 1) has been responsible for the SQL standard since 1987.
ISO stages
ISO stages by date
2019-09-10 : 10.99 New project approved
2019-09-10 : 20.00 New project registered in TC/SC work programme
2021-11-22 : 30.00 Committee draft (CD) registered
2021-11-23 : 30.20 CD study initiated
2022-02-25 : 30.60 Close of comment period
2022-08-29 : 30.92 CD referred back to Working Group
2022-08-29 : 30.00 Committee draft (CD) registered
2022-08-30 : 30.20 CD study initiated
2022-10-26 : 30.60 Close of comment period
2023-03-22 : 30.99 CD approved for registration as DIS
2023-03-24 : 40.00 DIS registered
2023-05-24 : 40.20 DIS ballot initiated: 12 weeks
2023-08-17 : 40.60 Close of voting
2023-11-28 : 40.99 Full report circulated: DIS approved for registration as FDIS
2023-12-11 : 50.00 Final text received or FDIS registered for formal approval
2024-01-26 : 50.20 Proof sent to secretariat or FDIS ballot initiated: 8 weeks
2024-03-23 : 50.60 Close of voting. Proof returned by secretariat
2024-03-23 : 60.00 International Standard under publication
2024-04-12 : 60.60 International Standard published
GQL property graph data model
GQL is a query language specifically for property graphs. A property graph closely resembles a conceptual data model, as expressed in an entity–relationship model or in a UML class diagram (although it does not include n-ary relationships linking more than two entities). Entities are modelled as nodes, and relationships as edges, in a graph. Property graphs are multigraphs: there can be many edges between the same pair of nodes. GQL graphs can be mixed: they can contain directed edges, where one of the endpoint nodes of an edge is the tail (or source) and the other node is the head (or target or destination), but they can also contain undirected (bidirectional or reflexive) edges.
Nodes and edges, collectively known as elements, have attributes. Those attributes may be data values, or labels (tags). Values of properties cannot be elements of graphs, nor can they be whole graphs: these restrictions intentionally force a clean separation between the topology of a graph, and the attributes carrying data values in the context of a graph topology. The property graph data model therefore deliberately prevents nesting of graphs, or treating nodes in one graph as edges in another. Each property graph may have a set of labels and a set of properties that are associated with the graph as a whole.
Current graph database products and projects often support a limited version of the model described here. For example, Apache Tinkerpop forces each node and each edge to have a single label; Cypher allows nodes to have zero to many labels, but relationships only have a single label (called a reltype). Neo4j's database supports undocumented graph-wide properties, Tinkerpop has graph values which play the same role, and also supports "metaproperties" or properties on properties. Oracle's PGQL supports zero to many labels on nodes and on edges, whereas SQL/PGQ supports one to many labels for each kind of element. The NGSI-LD information model specified by ETSI is an attempt at formally specifying property graphs, with node and relationship (edge) types that may play the role of labels in previously mentioned models and support semantic referencing by inheriting classes defined in shared ontologies.
The GQL project will define a standard data model, which is likely to be the superset of these variants, and at least the first version of GQL is likely to permit vendors to decide on the cardinalities of labels in each implementation, as does SQL/PGQ, and to choose whether to support undirected relationships.
Additional aspects of the ERM or UML models (like generalization or subtyping, or entity or relationship cardinalities) may be captured by GQL schemas or types that describe possible instances of the general data model.
Implementations
The first in-memory graph database that can interpret GQL is available. Aside from the implementation, one can also find a formalization and read the syntax of the specific subset of GQL.
Extending existing graph query languages
The GQL project draws on multiple sources or inputs, notably existing industrial languages and a new section of the SQL standard. In preparatory discussions within WG3 surveys of the history and comparative content of some of these inputs were presented. GQL is a declarative language with its own distinct syntax, playing a similar role to SQL in the building of a database application. Other graph query languages have been defined which offer direct procedural features such as branching and looping (Apache Tinkerpop's Gremlin), and GSQL, making it possible to traverse a graph iteratively to perform a class of graph algorithms, but GQL will not directly incorporate such features. However, GQL is envisaged as a specific case of a more general class of graph languages, which share a graph type system and a calling interface for procedures that process graphs.
SQL/PGQ Property Graph Query
Prior work by WG3 and SC32 mirror bodies, particularly in INCITS Data Management (formerly INCITS DM32), has helped to define a new planned Part 16 of the SQL Standard, which allows a read-only graph query to be called inside a SQL SELECT statement, matching a graph pattern using syntax which is very close to Cypher, PGQL and G-CORE, and returning a table of data values as the result. SQL/PGQ also contains DDL to allow SQL tables to be mapped to a graph view schema object with nodes and edges associated to sets of labels and set of data properties. The GQL project coordinates closely with the SQL/PGQ "project split" of (extension to) ISO 9075 SQL, and the technical working groups in the U.S. (INCITS DM32) and at the international level (SC32/WG3) have several expert contributors who work on both projects. The GQL project proposal mandates close alignment of SQL/PGQ and GQL, indicating that GQL will in general be a superset of SQL/PGQ.
More details about the pattern matching language can be found in the paper "Graph Pattern Matching in GQL and SQL/PGQ"
Cypher
Cypher is a language originally designed by Andrés Taylor and colleagues at Neo4j Inc., and first implemented by that company in 2011. Since 2015 it has been made available as an open source language description with grammar tooling, a JVM front-end that parses Cypher queries, and a Technology Compatibility Kit (TCK) of over 2000 test scenarios, using Cucumber for implementation language portability. The TCK reflects the language description and an enhancement for temporal datatypes and functions documented in a Cypher Improvement Proposal.
Cypher allows creation, reading, updating and deleting of graph elements, and is a language that can therefore be used for analytics engines and transactional databases.
Querying with visual path patterns
Cypher uses compact fixed- and variable-length patterns which combine visual representations of node and relationship (edge) topologies, with label existence and property value predicates. (These patterns are usually referred to as "ASCII art" patterns, and arose originally as a way of commenting programs which used a lower-level graph API.) By matching such a pattern against graph data elements, a query can extract references to nodes, relationships and paths of interest. Those references are emitted as a "binding table" where column names are bound to a multiset of graph elements. The name of a column becomes the name of a "binding variable", whose value is a specific graph element reference for each row of the table.
For example, a pattern will generate a two-column output table. The first column named will contain references to nodes with a label . The second column named will contain references to nodes with a label , denoting the city where the person lives.
The binding variables and can then be dereferenced to obtain access to property values associated with the elements referred to by a variable. The example query might be terminated with a , resulting in a complete query like this:
MATCH (p:Person)-[:LIVES_IN]->(c:City)
RETURN p.first_name, p.last_name, c.name, c.state
This would result in a final four-column table listing the names of the residents of the cities stored in the graph.
Pattern-based queries are able to express joins, by combining multiple patterns which use the same binding variable to express a natural join using the clause:
MATCH (p:Person)-[:LIVES_IN]->(c:City), (p:Person)-[:NATIONAL_OF]->(EUCountry)
RETURN p.first_name, p.last_name, c.name, c.state
This query would return the residential location only of EU nationals.
An outer join can be expressed by :
MATCH (p:Person)-[:LIVES_IN]->(c:City) OPTIONAL MATCH (p:Person)-[:NATIONAL_OF]->(ec:EUCountry)
RETURN p.first_name, p.last_name, c.name, c.state, ec.name
This query would return the city of residence of each person in the graph with residential information, and, if an EU national, which country they come from.
Queries are therefore able to first project a sub-graph of the graph input into the query, and then extract the data values associated with that subgraph. Data values can also be processed by functions, including aggregation functions, leading to the projection of computed values which render the information held in the projected graph in various ways. Following the lead of G-CORE and Morpheus, GQL aims to project the sub-graphs defined by matching patterns (and graphs then computed over those sub-graphs) as new graphs to be returned by a query.
Patterns of this kind have become pervasive in property graph query languages, and are the basis for the advanced pattern sub-language being defined in SQL/PGQ, which is likely to become a subset of the GQL language. Cypher also uses patterns for insertion and modification clauses ( and ), and proposals have been made in the GQL project for collecting node and edge patterns to describe graph types.
Cypher 9 and Cypher 10
The current version of Cypher (including the temporal extension) is referred to as Cypher 9. Prior to the GQL project it was planned to create a new version, Cypher 10 [REF HEADING BELOW], that would incorporate features like schema and composable graph queries and views. The first designs for Cypher 10, including graph construction and projection, were implemented in the Cypher for Apache Spark project starting in 2016.
PGQL
PGQL
is a language designed and implemented by Oracle Inc., but made available as an open source specification, along with JVM parsing software. PGQL combines familiar SQL SELECT syntax including SQL expressions and result ordering and aggregation with a pattern matching language very similar to that of Cypher. It allows the specification of the graph to be queried, and includes a facility for macros to capture "pattern views", or named sub-patterns. It does not support insertion or updating operations, having been designed primarily for an analytics environment, such as Oracle's PGX product. PGQL has also been implemented in Oracle Big Data Spatial and Graph, and in a research project, PGX.D/Async.
G-CORE
G-CORE is a research language designed by a group of academic and industrial researchers and language designers which draws on features of Cypher, PGQL and SPARQL. The project was conducted under the auspices of the Linked Data Benchmark Council (LDBC), starting with the formation of a Graph Query Language task force in late 2015, with the bulk of the work of paper writing occurring in 2017. G-CORE is a composable language which is closed over graphs: graph inputs are processed to create a graph output, using graph projections and graph set operations to construct the new graph. G-CORE queries are pure functions over graphs, having no side effects, which mean that the language does not define operations which mutate (update or delete) stored data. G-CORE introduces views (named queries). It also incorporates paths as elements in a graph ("paths as first class citizens"), which can be queried independently of projected paths (which are computed at query time over node and edge elements). G-CORE has been partially implemented in open-source research projects in the LDBC GitHub organization.
GSQL
GSQL is a language designed for TigerGraph Inc.'s proprietary graph database. Since October 2018 TigerGraph language designers have been promoting and working on the GQL project. GSQL is a Turing-complete language that incorporates procedural flow control and iteration, and a facility for gathering and modifying computed values associated with a program execution for the whole graph or for elements of a graph called accumulators. These features are designed to enable iterative graph computations to be combined with data exploration and retrieval. GSQL graphs must be described by a schema of vertexes and edges, which constrains all insertions and updates. This schema therefore has the closed world property of an SQL schema, and this aspect of GSQL (also reflected in design proposals deriving from the Morpheus project) is proposed as an important optional feature of GSQL.
Vertexes and edges are named schema objects which contain data but also define an imputed type, much as SQL tables are data containers, with an associated implicit row type. GSQL graphs are then composed from these vertex and edge sets, and multiple named graphs can include the same vertex or edge set. GSQL has developed new features since its release in September 2017, most notably introducing variable-length edge pattern matching using a syntax related to that seen in Cypher, PGQL and SQL/PGQ, but also close in style to the fixed-length patterns offered by Microsoft SQL/Server Graph
GSQL also supports the concept of Multigraphs
which allow subsets of a graph to have role-based access control. Multigraphs are important for enterprise-scale graphs that need fine-grain access control for different users.
Morpheus: multiple graphs and composable graph queries in Apache Spark
The opencypher Morpheus project implements Cypher for Apache Spark users. Commencing in 2016, this project originally ran alongside three related efforts, in which Morpheus designers also took part: SQL/PGQ, G-CORE and design of Cypher extensions for querying and constructing multiple graphs. The Morpheus project acted as a testbed for extensions to Cypher (known as "Cypher 10") in the two areas of graph DDL and query language extensions.
Graph DDL features include
definition of property graph views over JDBC-connected SQL tables and Spark DataFrames
definition of graph schemas or types defined by assembling node type and edge type patterns, with subtyping
constraining the content of a graph by a closed or fixed schema
creating catalog entries for multiple named graphs in a hierarchically organized catalog
graph data sources to form a federated, heterogeneous catalog
creating catalog entries for named queries (views)
Graph query language extensions include
graph union
projection of graphs computed from the results of pattern matches on multiple input graphs
support for tables (Spark DataFrames) as inputs to queries ("driving tables")
views which accept named or projected graphs as parameters.
These features have been proposed as inputs to the standardization of property graph query languages in the GQL project.
See also
Graph Modeling Language (GML)
GraphQL
Cypher (query language)
Graph database
Graph (abstract data type)
Graph traversal
Regular path query
References
External links
GQL Standard (Official website)
Computer languages
Query languages
ISO/IEC standards | Graph Query Language | [
"Technology"
] | 3,981 | [
"Computer science",
"Computer languages"
] |
61,985,302 | https://en.wikipedia.org/wiki/Sony%20CLI%C3%89%20PEG-TG50 | The Clié PEG-TG50 is a Personal Digital Assistant (PDA) which was manufactured by Sony, released in March 2003. Running the Palm operating system (version 5.0), the TG50 was notable as it featured a built-in backlit mini qwerty keyboard, in lieu of a dedicated handwriting recognition area as was the trend on most other PDAs.
This handheld featured a 320x320 colour LCD, bluetooth, and additional multimedia features, including MP3 and ATRAC3 audio playback, a voice-recorder, and a slot for MemoryStick PRO memory cards. The TG50 was powered by a 200 MHz Intel XScale PXA250 processor, with 16MB of RAM, 11MB of which was available for user data storage. The TG50 also featured the "Jog Dial" scroll wheel on the side of the device, as was common on Sony Clie models, and came with a flip cover to protect the front face of the device when not in use.
Specifications
Palm OS: 5.0
CPU: Intel XScale PXA250 200 MHz
Audio codec: AK4534VN
PMIC: Panasonic AN32502A
Touch controller: Analog Devices AD7873
Gate array / IO expander: NEC 65943-L63
Memory: 16MB RAM (11MB avail.), 16MB ROM
Display: 320x 320 transflective back-lit TFT-LCD, 16bit Colour (65k colours)
Sound: Internal audio amplifier, Rear speaker, Mono Mic, Stereo Headphone out.
External Connectors: USB
Expansion: Memory Stick Pro, MSIO
Wireless: Infrared IrDA, Bluetooth
Battery: Rechargeable Li-Ion Polymer (900mAh)
Size & Weight: 5.0" x 2.8" x 0.63"; 6.2 oz.
Color: Silver
See also
Sony CLIÉ TH Series - The successor to the TG series.
External links
TG50 Review at Palm Info Center
TG50 Review at CNet
TG50 Review at BrightHand
TG50 review at PCMag
References
Sony CLIÉ | Sony CLIÉ PEG-TG50 | [
"Technology"
] | 443 | [
"Mobile computer stubs",
"Mobile technology stubs"
] |
61,985,541 | https://en.wikipedia.org/wiki/Protoxin-II | Protoxin-II, also known as ProTx-II, PT-II or β/ω-TRTX-Tp2a, is a neurotoxin that inhibits certain voltage-gated calcium and voltage-gated sodium channels. This toxin is a 30-residue disulfide-rich peptide that has unusually high affinity and selectivity toward the human Nav1.7. channel.
Sources
Protoxin-II is a neurotoxin that is derived from the venom of the Peruvian green velvet tarantula (Thrixopelma pruriens).
Chemistry
ProTx-II is a 30-amino acid peptide with a molecular weight of 3826.65 Da. The structure of ProTx-II is amphipathic, with mostly hydrophobic residues on one face of the toxin. The toxin is formed by an inhibitor cystine knot (ICK) backbone region and a flexible C-terminal tail region.
Target
ProTx-II inhibits several human sodium channel subtypes, ranging from Nav1.1 up to Nav1.8. However, this toxin is, at least, 100-fold more potent against Nav1.7 than other human Nav channel subtypes. At a concentration of 0.3 nM, this toxin blocks Nav1.7 by 50%.
Besides sodium channels, ProTx-II also inhibits some subtypes of voltage-gated calcium channels, Cav1.2 and Cav3.2. From the fact that ProTx-II is able to inhibit several sodium and calcium channel subtypes, we can infer that the toxin-channel interaction surface is conserved between these channels.
Mechanism of action
ProTx-II acts as an antagonist of Nav1.7 by binding to the voltage-sensor domain 2 (VSD-II) of the channel. The toxin inhibits the activation of Nav channels by binding to the linker in the L3-4 loop (between the S3 and S4 segments) above the central cavity of VSD-II, which is known as site 4. ProTx-II inhibits sodium currents by shifting the voltage-dependence of the channel activation to more positive potentials. The toxin uses a similar action mechanism on the Cav1.2 and Cav1.3 voltage-gated calcium channels: shifting the activation of these L-type and T-type calcium channels, respectively, to more positive voltages.
ProTx-II also inhibits fast inactivation of the Nav channel by binding to VSD-IV in the resting configuration of the channel. The inhibition of activation and of inactivation appear to be independent processes. For instance, mutations in domain IV substantially affect the inhibition of inactivation without changing the inhibition of activation by ProTx-II. Likewise, mutations in domain II mostly affect the inhibition of activation. Therefore, it seems that ProTx-II is able to interact with two independent sites (DIV and DII) at the same time. Another factor that supports this theory is the estimated IC50. The IC50 for inhibition of activation is approximately 400-fold smaller than the one calculated for inhibition of inactivation, again suggesting that the inhibition of activation and the inhibition of inactivation are independent processes.
Biological effects
ProTx-II provokes an analgesic effect on rats. The toxin acts on free nerve endings and primary sensory neurons after burn injury. ProTx-II produces an inhibitory effect on spinal nociceptive processing by inhibiting the Nav1.7 sodium channel.
References
Ion channel toxins
Spider toxins
Neurotoxins | Protoxin-II | [
"Chemistry"
] | 762 | [
"Neurochemistry",
"Neurotoxins"
] |
61,986,499 | https://en.wikipedia.org/wiki/Vejocalcin | Vejocalcin (VjCa, also called Vejocalcine) is a toxin from the venom of the Mexican scorpion Vaejovis mexicanus. Vejocalcin is a member of the calcin family of toxins. It acts as a cell-penetrating peptide (CPP); it binds with high affinity and specificity to skeletal ryanodine receptor 1 (RYR1) of the sarcoplasmic reticulum, thereby triggering calcium release from intracellular stores.
Source and etymology
Vejocalcin is produced by Vaejovis mexicanus, a scorpion endemic to North and Central America. While Vaejovis mexicanus was originally described in 1836, vejocalcin was only isolated in 2016. This toxin was named after the scorpion that produces the peptide as well as its structural similarity to other toxins of the scorpion calcin family.
Chemistry
Homology and family
On the basis of its amino acid structure, vejocalcin belongs to the family of scorpion calcin toxins, a group of selective, high-affinity membrane-permeable ligands of RyRs. Vejocalcin shares significant sequence similarity with other members of this family.
Structure
Vejocalcin has a molecular mass of approximately 3.8 kDa and an isoelectric point of 9.3.
It is a relatively small protein, consisting of only 33 amino acids:
Ala-Asp-Cys-Leu-Ala-His-Leu-Lys-Leu-Cys-Lys-Lys-Asn-Asn-Asp-Cys-Cys-Ser-Lys-Lys-Cys-Ser-Arg-Arg-Gly-Thr-Asn-Pro-Glu-Glu-Arg-Cys-Arg
Notably, two calcins produced by two closely related scorpions - vejocalcin from Vaejovis mexicanus and intrepicalcin from Vaejovis intrepidus - display a 97% similarity in their primary sequence, differing in only one amino acid at position 14 (Asn and Lys, respectively). Despite this marked similarity, vejocalcin exhibits a binding affinity to RyR1 that is 4.7-fold higher than that of intrepicalcin.
Vejocalcin shows an arrangement of charged residues, in which most of the positively charged residues are segregated on one side of the molecule, whereas neutral and negatively charged residues are clustered on the opposite side. This arrangement generates a discrete dipole moment (DM) and appears to be a prevalent feature across all toxins of the calcin family. Interestingly, vejocalcin has the smallest charge segregation among peptides in the calcin family. However, comparisons among different calcins show that, for each peptide, there appears to be no correlation between DM, binding affinity and subconductance state attributes.
Maturation of vejocalcin involves post-translational modification of its tertiary structure. Specifically, three disulfide bonds are formed between cysteine residues in positions 3–17, 10–21, and 16–32. These three disulfide bonds arrange themselves spatially to form a “disulfide through disulfide knot”, which is an evolutionary conserved structural motif known as the inhibitor cystine knot motif (ICK motif), thus defining the whole protein as a knottin. This three-dimensional arrangement confers the protein remarkable stability and builds the structural core of its pharmacological active site. ICK motifs have also been shown to be characteristic of calcium channel blocking toxins produced by snails and spiders.
Target
Though the exact target of vejocalcin on RyR1 remains unclear, it is thought that calcins bind to RyR1 at a binding site different from that of ryanodine, as the combination of calcins and ryanodine can have a cumulative effect on RyR1. Like most calcins, vejocalcin shows a fast association rate, as well as a reversible effect, due to free dissociation from the binding site. Single channel experiments and modeling of the kinetics and gating of RyR1 during calcin exposure suggest that the RyR1 transits between closed and open states and a single calcin molecule binds to the channel when the channel is in the open state. It is hypothesized that globular calcins, such as vejocalcin, can affect RyR1 channels by entering the cytosolic opening and accessing the binding site in the core of the channel. The precise mechanism by which calcins bind to their target, however, remains controversial.
Mode of action
Using single channel electrophysiological recordings, it was found that RyR1 channels exposed to vejocalcin move from an open state to a subconductance open state, with the latter conducting approximately 60% of the full-conductance level. Evidence from [3H]ryanodine binding assays shows that vejocalcin is able to enhance [3H]ryanodine binding to RyR1. This effect of vejocalcin is dose-dependent and happens at all levels, with an apparent dissociation constant Kd= 3.7 ± 0.4 nM. Mechanistically, vejocalcin is thought to promote this action by increasing the “openness” of the channel in a long-lasting, reversible and transient manner.
Noteworthy, vejocalcin triggers dose-dependent release from skeletal sarcoplasmic vesicles. High concentrations of vejocalcin drive incomplete, submaximal depletion of load through the process of calcium-induced calcium release (CICR) from intracellular stores. These functional effects are also characteristic of other calcins as detected in structure–function relationship assays.
Toxicity
While the effects of vejocalcin have not yet been studied, in vivo toxicity testing of hemicalcin has shown that the peptide induces neurotoxic symptoms in mice, followed by death. The comparable activity of vejocalcin and hemicalcin on RyR1 suggests a similar toxicity of vejocalcin. However, given the high variability in RyR-affinity between various calcins, the LD50 may vary significantly.
Therapeutic use
Despite their highly ionized nature, calcins are able to penetrate cell membranes with high efficiency. Thus, they act as cell-penetrating peptides (CPPs) and can transport large, membrane-impermeable cargos across the plasma membrane directly into the cell. This property of calcins, combined with their high-affinity and specificity to RyRs, may have positive implications for intracellular drug delivery, particularly for the treatment of RyR channelopathies.
References
External links
Knottin Database
UniProt Vejocalcin
Ion channel toxins
Neurotoxins
Scorpion toxins | Vejocalcin | [
"Chemistry"
] | 1,437 | [
"Neurochemistry",
"Neurotoxins"
] |
61,986,578 | https://en.wikipedia.org/wiki/Trained%20immunity | Trained immunity is a long-term functional modification of cells in the innate immune system which leads to an altered response to a second unrelated challenge. For example, the BCG vaccine leads to a reduction in childhood mortality caused by unrelated infectious agents. The term "innate immune memory" is sometimes used as a synonym for the term trained immunity which was first coined by Mihai Netea in 2011. The term "trained immunity" is relatively new – immunological memory has previously been considered only as a part of adaptive immunity – and refers only to changes in innate immune memory of vertebrates. This type of immunity is thought to be largely mediated by epigenetic modifications. The changes to the innate immune response may last up to several months, in contrast to the classical immunological memory (which may last up to a lifetime), and is usually unspecific because there is no production of specific antibodies/receptors. Trained immunity has been suggested to possess a transgenerational effect, for example the children of mothers who had also received vaccination against BCG had a lower mortality rate than children of unvaccinated mothers. The BRACE trial is currently assessing if BCG vaccination can reduce the impact of COVID-19 in healthcare workers. Other vaccines are also thought to induce immune training such as the DTPw vaccine.
Immune cells subject to training
Trained immunity is thought to be largely mediated by functional reprogramming of myeloid cells. One of the first described adaptive changes in macrophages were associated with lipopolysaccharide tolerance, which resulted in the silencing of inflammatory genes. Similarly, Candida albicans and fungal β-glucan trigger changes in monocyte histone methylation, this functional reprogramming eventually provides protection against reinfection. Also, a non-specific manner of protection in training with different microbial ligands was shown, for example treatment with fungal β-glucan induced protection against Staphylococcus aureus infection or CpG oligodeoxynucleotide training protecting against infectious with Escherichia coli.
Evidence of trained immunity is found mainly at monocytes/macrophages and NK cells and, less at γδ T cells and innate lymphoid cells.
Monocytes, macrophages and dendritic cells
Monocytes/macrophages can undergo epigenetic modifications after a ligation of their pattern recognition receptors (PRRs). This ligation prepares these cells for a second encounter with the training pathogen. The secondary response may be heightened not only against the training pathogen, but also against different pathogens whose antigens are recognized by the same PRRs. This effect has been observed when stimulating cells by β-glucan, Candida albicans, or by vaccination against tuberculosis with a vaccine containing BCG. Monocytes are very short-lived cells; however, the heightened secondary response can be spotted even several months after the primary stimulation. This shows that the immune memory is created at the level of progenitor cells, but so far it is not known how this memory is achieved. Though the epigenetic modification is beneficial to the innate immune system response, it can impair macrophage resolution pathways- promoting unfavorable tissue remodeling at the inflammatory site. Additionally, dendritic cells isolated from mice exposed to Cryptococcus neoformans, manifested an immunological memory response, associated with a strong interferon-γ production after C. neoformans reinfection.
Trained immunity can shift macrophages toward a pro-inflammatory glycolytic M1 phenotype by an Akt/mTor HIF1α dependent pathway, away from the M2 phenotype in which macrophages maintain the Krebs cycle and oxidative phosphorylation
NK cells and innate lymphoid cell
The trained immunity involving NK cells looks more like classic immunological memory, because there is development of at least partially-specific clones of NK cells. These cells have receptors on their surface against the antigens with which they came in contact during the first stimulation. For example, after the encounter with cytomegalovirus, certain clones of NK cells (those that have a Ly49H receptor on their surface) expand and then show signs of immunological memory. Reinfection of memory NK cells in mouse led to an enhanced cytokine production by Ly49H receptor with a more specific response to pathogen. In human NK cells, this is mediated by NKG2C a receptor with a similar function as mouse Ly49H. NK cells are known for their memory specific to different pathogens. The first descriptions of NK memory-like phenotype were made on mouse models with murine cytomegalovirus infections. Other viral infections such as Herpes Simplex Virus or Influenza Virus also induce memory or memory-like responses. Memory or memory-like phenotype can be caused by bacterial phatogens, for example Mycobacterium tuberculosis, or eukaryotic pathogens, for example Toxoplasma gondii.
Another resident cell group 1 innate lymphoid cells (ILC1s) were discovered in liver, which expand after the infection with murine cytomegalovirus and which have manifest transcriptional, phenotypical and epigenetic changes. For the induction of ILC1s, pro-inflammatory cytokine and antigen specificity are critical. Lung specific ILC2 showed memory-like phenotype after allergen exposure
Epigenetic reprogramming
Trained immunity relies on epigenetic reprogramming which leads to a stronger and rapid response to recurrent triggers. There are multiple potential epigenetic mechanisms such as changes in chromatin accessibility, DNA methylation or histone modifications. Long non-coding RNAs (lncRNAs) are also critical to epigenetic reprogramming, such as their role in the assignment of H3K4me3 markers to genome which modulates gene expression. Additionally, transcription factors, including STAT4 and RUNX family transcription factors play a role in the introduction of histone modifications. Cell metabolism is a crucial mediator of trained immunity, for example monocytes trained with β-glucan had an increased aerobic glycolysis. Additionally, priming with β-glucan resulted in epigenetic upregulation of genes involved in glycolysis 1 week later. Subsequently, a cross-talk between glycolysis, glutaminolysis and cholesterol synthesis pathways was demonstrated as essential for trained immunity – β-glucan-triggered monocytes. In addition, accumulation of fumarate, caused by glutamine addition into tricarboxylic acid cycle, led to epigenetic reprogramming similar to β-glucan treatment
References
Immunology | Trained immunity | [
"Biology"
] | 1,421 | [
"Immunology"
] |
61,987,255 | https://en.wikipedia.org/wiki/Nokia%207.2 | The Nokia 7.2 is an Android smartphone produced by HMD Global. The 7.2 was announced on 6 September 2019 at IFA and prices at launch started at $349 (£249) for the cheapest model.
Changes from the Nokia 7.1
The Nokia 7.2 has three rear cameras, including a 0.6x zoom ultrawide camera, and one front camera. The main rear camera is a 48 MP camera that is set to 12 MP by default, improving the quality of the camera, in terms of megapixels, in comparison the Nokia 808 PureView and Lumia 1020. A dedicated night mode camera was introduced in the 7.2, which claims to help "improve low-light photography".
The screen is larger than on the 7.1, with 99.1 cm2 (6.3") instead of 85.1 cm2 (5.84"). The display has a smaller chin and bezels, along with a thinner dewdrop notch at the top. The 7.2 is heavier, weighing 180g rather than the 160g of the Nokia 7.1. The addition of Nokia Face ID, made by Truly Secure, has also been added to the software of the 7.2.
In terms of the phone's exterior, there is a dedicated Google Assistant button on the left of the phone, which can be pressed to quickly activate the Google Assistant, or held and released for the Google Assistant to start and stop listening. It can also be re-mapped in the phone settings to open an app of choice.
The 7.2 has a more powerful SoC, with a Snapdragon 660 rather than a 636. The 7.2 comes with a 3500 mAh battery, while the 7.1 has 3060 mAh. However, the 7.2 does not support fast charging and the phone charges at 10 Watts instead of 18. Expandable storage has increased from 400 to 512 GB.
Differences between the Nokia 7.2 and 6.2
Although the Nokia 7.2 and 6.2 are very similar phones and almost identical in appearance, there are a few differences between them. The biggest difference is the cameras. The main rear and front cameras of the 7.2 have a higher megapixel count than the 6.2 (48 MP to 16 MP and 20 MP to 8 MP respectively). Unlike the 6.2, the camera app on the 7.2 has Zeiss branded effects that aim to replicate the effects of Zeiss lenses. Additionally, the Nokia 7.2 claims to take better low-light photos.
In terms of core processes the 7.2 comes with the more powerful Snapdragon 660 (rather than 636) processor and comes with 4-6 GB of RAM instead of 3-4 GB. The storage also starts at 64 GB rather than 32. The Nokia 7.2 comes in colors including Charcoal, Cyan Green, and Ice, while the Nokia 6.2 comes in Ceramic Black and Ice.
Models
The global version of the phone comes in 3 models: 4 GB of RAM with 64 GB of storage; 6 GB of RAM with 64 GB of storage; and 6 GB of RAM with 128 GB of storage. The Chilean version of the Nokia 7.2 (TA-1178) comes with 4 GB of RAM and 128 GB of internal storage.
Reception
The Verge said the Nokia 7.2 is "competent and almost as good as the [Google] Pixel 3A", calling it Nokia's "most confident creation yet". The 7.2 was given a score of 7/10.
Digital Trends said that the phone "aims high but misses the mark", giving it a 6/10 score.
References
7.2
Mobile phones introduced in 2019
Phablets
Mobile phones with multiple rear cameras | Nokia 7.2 | [
"Technology"
] | 781 | [
"Crossover devices",
"Phablets"
] |
61,987,741 | https://en.wikipedia.org/wiki/Sony%20Xperia%205 | The Sony Xperia 5 is an Android smartphone marketed and manufactured by Sony. Part of Sony's flagship Xperia series, it was unveiled at the annual IFA event on September 5, 2019. The device is a cheaper, more compact variant of the Xperia 1.
Design
The Xperia 5 heavily resembles the Xperia 1, but has a smaller form factor. Like the 1, it uses aluminum for the frame and Corning Gorilla Glass 6 for the screen and back panel. The button layout is retained, with the volume, power and shutter release buttons as well as the always-on fingerprint scanner all located on the right side of the phone. However, the card slot has been moved to the left side as opposed to the Xperia 1's top-mounted tray. Notably, the camera module, color sensing (RGBC-IR sensor) and LED flash have been relocated to the upper left-hand corner of the device as on earlier Xperia phones. The earpiece/top speaker, front-facing camera, notification LED and various sensors are housed in the top bezel. The bottom edge has the primary microphone and a downward-firing speaker next to the USB-C port. At 158 mm × 68 mm × 8.2 mm, the Xperia 5 is 9 mm shorter and 4 mm narrower than the 1, but has the same depth. The decrease in dimensions also results in the device being lighter at 164g (5.78 oz); it weighs 14g (0.5 oz) less than the 1. The same IP65/68 rating is present, and four colors are available: Blue, Red, Black and Grey.
Specifications
Hardware
The chipset is carried over from the Xperia 1: a Qualcomm Snapdragon 855 SoC and an Adreno 640 GPU, accompanied by 6 GB of LPDDR4X RAM. The Xperia 5 is only available with 128 GB of UFS internal storage, lacking the 64 GB model of the 1, and microSD expansion is supported up to 512 GB with a hybrid dual-SIM setup. The display is smaller and has a lower resolution than the Xperia 1, using a 6.1 in (155mm) 21:9 1080p (2520 × 1080) HDR OLED panel which results in a pixel density of 449 ppi. The camera system is similar to the Xperia 1 in terms of hardware (a 12 MP primary lens, a 12 MP telephoto lens and a 12 MP ultrawide lens with an 8 MP front camera), but is missing the 960fps slow motion capabilities due to lacking a stacked memory main sensor. However, Sony improved the Eye AF autofocus allowing it to work at 30fps. The battery is 6% smaller than the Xperia 1 due to the reduced physical footprint, with a 3140mAh cell which can be recharged at up to 18W via the USB-C 3.1 port. The 3.5mm audio jack is still absent, but an active external amplifier is still included; connectivity options mostly remain the same.(The Japanese SO-01M variant was available with 64 GB of internal storage only)
Software
The Xperia 5 runs on Android 9.0 "Pie", along with Smart Stamina battery saving modes and Sony's proprietary multimedia apps. It features an improved Side Sense. It works through a pair of touch-sensitive areas on either side of the phone. A tap or slide triggers various actions set by the user, most of which configurable including the sensitivity of the touch areas. Another feature by the Side Sense is Pair shortcut which, upon launch from the Side Sense window, will trigger a split-screen setup with the selected pair of user-customizable apps instantly. In December 2019, Sony began to release Android 10 for the Xperia 5. The Phone is currently upgradeable to Android 11 which was its last major release before discontinuation.
References
External links
Android (operating system) devices
Sony smartphones
Mobile phones introduced in 2019
Mobile phones with multiple rear cameras
Mobile phones with 4K video recording
Discontinued flagship smartphones | Sony Xperia 5 | [
"Technology"
] | 848 | [
"Discontinued flagship smartphones",
"Flagship smartphones"
] |
61,987,928 | https://en.wikipedia.org/wiki/Neurotoxin%20B-IV | Neurotoxin B-IV is a venom peptide secreted by a large marine worm called Cerebratulus lacteus that inhabits the northeastern coast of North America. This neurotoxin belongs to a major type of B polypeptide neurotoxins, which appear to be selectively toxic for crustaceans. The mode of action for neurotoxin B-IV has not been clearly established. However, it is likely that B neurotoxins prolong the repolarization phase of action potentials by interacting with voltage-gated sodium channels.
Etymology and Source
Neurotoxin B-IV is found in the mucus secretions of the Atlantic coast marine worm Cerebratulus lacteus. Cerebratulus lacteus produces two major types of polypeptide neurotoxins namely A and B. Toxins B include four neurotoxins designated B-I to B-IV.
Chemistry
Structure
Neurotoxin B-IV has a helical structure that looks like a hairpin, and consists of 55 amino acid residues, cross-linked by four disulfide bonds. Its molecular size is about 6000 Dalton. The sequence of the neurotoxin B-IV is ASATWGAAYPACENNCRKKYDLCIRCQGKWAGKRGKCAAHCIIQKNNCKGKCKKE.
Homology
The complete structures for two of the four B toxins (B-II and B-IV) have been determined. Toxin B-II differs from B-IV in that the secondary structure of Toxin B-II contains about 15-20% less α-helixes than B-IV due to the differences in the primary structure of the two proteins; amino acids Ala in position 3, Ala in position 7 and Ala in position 8 in B-IV are substituted by amino acids Ser, Gly and Ser in B-II respectively.
No homology is displayed with other sodium channel selective toxins, such as scorpion and sea anemone venom toxins, despite being similar in size, basicity, and degree of cross-linking. The secondary structures of scorpion and anemone toxins are largely organized into β-sheet conformations, while the secondary structures of B toxins organize in α-helical conformations.
Family
Neurotoxin B-IV belongs to a family of four homologous polypeptide neurotoxins designated B-I to B-IV which are produced by the marine worm Cerebratulus lacteus.
Target
Neurotoxin B-IV displays a high affinity binding to a single class of receptor sites on crustacean axon membrane vesicles. B-IV binds to a nerve membrane protein in crustaceans which is similar in size to the β-subunit of sodium channels in nerve and muscle of mammals. The binding site for toxin B-IV is distinct from sodium channel site III, which is targeted by both scorpion and sea anemone toxins.
Mode of Action
Neurotoxin B-IV appears to prolong the repolarization phase of the action potential in crustacean nerve sodium channels but does not affect the initial opening of these channels. It is likely that this neurotoxin causes a small depolarization of the resting potential in lobster and crayfish walking leg nerve.
Cationic residues are important determinants for polypeptide neurotoxins' function. Specifically, the arginine residues, located within the N-terminal helix, seem to be essential for the activity of neurotoxin B-IV and are most likely directly involved in binding.
Toxicity
Neurotoxin B-IV is selectively toxic to crustaceans inducing paralysis, at mean concentrations of about 20 ng/g of body weight. This neurotoxin is the most abundant of the B neurotoxin family and 15-20-fold less toxic than neurotoxin B-II.
References
Ion channel toxins
Invertebrate toxins
Neurotoxins | Neurotoxin B-IV | [
"Chemistry"
] | 845 | [
"Neurochemistry",
"Neurotoxins"
] |
61,988,019 | https://en.wikipedia.org/wiki/Water%20distribution%20system | A water distribution system is a part of water supply network with components that carry potable water from a centralized treatment plant or wells to consumers to satisfy residential, commercial, industrial and fire fighting requirements.
Definitions
Water distribution network is the term for the portion of a water distribution system up to the service points of bulk water consumers or demand nodes where many consumers are lumped together. The World Health Organization (WHO) uses the term water transmission system for a network of pipes, generally in a tree-like structure, that is used to convey water from water treatment plants to service reservoirs, and uses the term water distribution system for a network of pipes that generally has a loop structure to supply water from the service reservoirs and balancing reservoirs to consumers.
Components
A water distribution system consists of pipelines, storage facilities, pumps, and other accessories.
Pipelines laid within public right of way called water mains are used to transport water within a distribution system. Large diameter water mains called primary feeders are used to connect between water treatment plants and service areas. Secondary feeders are connected between primary feeders and distributors. Distributors are water mains that are located near the water users, which also supply water to individual fire hydrants. A service line is a small diameter pipe used to connect from a water main through a small tap to a water meter at user's location. There is a service valve (also known as curb stop) on the service line located near street curb to shut off water to the user's location.
Storage facilities, or distribution reservoirs, provide clean drinking water storage (after required water treatment process) to ensure the system has enough water to service in response to fluctuating demands (service reservoirs), or to equalize the operating pressure (balancing reservoirs). They can also be temporarily used to serve fire fighting demands during a power outage. The following are types of distribution reservoirs:
Underground storage reservoir or covered finished water reservoir: An underground storage facility or large ground-excavated reservoir that is fully covered. The walls and the bottom of these reservoirs may be lined with impermeable materials to prevent ground water intrusion.
covered finished water reservoir: A large ground-excavated reservoir that has adequate measures or lining to prevent surface water runoff and ground water intrusion but does not have a top cover. This type of reservoir is less desirable as the water will not be further treated before distribution and is susceptible to contaminants such as bird waste, animal and human activities, algal bloom, and airborne deposition.
Surface reservoir (also known as ground storage tank and ground storage reservoir): A storage facility built on the ground with the wall lined with concrete, shotcrete, asphalt, or membrane. A surface reservoir is usually covered to prevent contamination. They are typically located in high elevation areas that have enough hydraulic head for distribution. When a surface reservoir at ground level cannot provide a sufficient hydraulic head to the distribution system, booster pumps will be required.
Water tower (also known as elevated surface reservoir): An elevated water tank. A few common types are spheroid elevated storage tank, a steel spheroid tank on top of a small-diameter steel column; composite elevated storage tank, a steel tank on a large-diameter concrete column; and hydropillar elevated storage tanks, a steel tank on a large-diameter steel column. The space within the large column below the water tank can be used for other purposes such as multi-story office space and storage space. A main concern for using water towers in the water distribution system is the aesthetic of the area.
Standpipe: A water tank that is a combination of ground storage tank and water tower. It is slightly different from an elevated water tower in that the standpipe allows water storage from the ground level to the top of the tank. The bottom storage area is called supporting storage, and the upper part which would be at the similar height of an elevated water tower is called useful storage.
Sump: This is a contingency water storage facility that is not used to distribute water directly. It is typically built underground in a circular shape with a dome top above ground. The water from a sump will be pumped to a service reservoir when it is needed.
Storage facilities are typically located at the center of the service locations. Being at the central location reduces the length of the water mains to the services locations. This reduces the friction loss when water is transported over a water main.
Topologies
In general, a water distribution system can be classified as having a grid, ring, radial or dead end layout.
A grid system follows the general layout of the road grid with water mains and branches connected in rectangles. With this topology, water can be supplied from several directions allowing good water circulation and redundancy if a section of the network has broken down. Drawbacks of this topology include difficulty sizing the system.
A ring system has a water main for each road, and there is a sub-main branched off the main to provide circulation to customers. This topology has some of the advantages of a grid system, but it is easier to determine sizing.
A radial system delivers water into multiple zones. At the center of each zone, water is delivered radially to the customers.
A dead end system has water mains along roads without a rectangular pattern. It is used for communities whose road networks are not regular. As there are no cross-connections between the mains, water can have less circulation and therefore stagnation may be a problem.
Integrity of the systems
The integrity of the systems are broken down into physical, hydraulic, and water quality.
The physical integrity includes concerns on the ability of the barriers to prevents contaminations from the external sources to get into water distribution systems. The deterioration can be caused by physical or chemical factors.
The hydraulic integrity is an ability to maintain adequate water pressure inside the pipes throughout distribution systems. It also includes the circulation and length of time that the water travels within a distribution system which has impacts on the effectiveness of the disinfectants.
The water quality integrity is a control of degradations as the water travels through distribution systems. The impacts of water quality can be caused by physical or hydraulic integrity factors. The water quality degradations can also take place within the distribution systems such as microorganism growth, nitrification, and internal corrosion of the pipes.
Network analysis and optimization
Analyses are done to assist in design, operation, maintenance and optimization of water distribution systems. There are two main types of analyses: hydraulic, and water quality behavior as it flows through a water distribution system. Optimizing the design of water distribution networks is a complex task. However, a large number of methods have already been proposed, mainly based on metaheuristics. Employing mathematical optimization techniques can lead to substantial construction savings in these kinds of infrastructures.
Hazards
Hazards in water distribution systems can be in the forms of microbial, chemical and physical.
Most microorganisms are harmless within water distribution systems. However, when infectious microorganisms enter the systems, they form biofilms and create microbial hazards to the users. Biofilms are usually formed near the end of the distribution where the water circulation is low. This supports their growth and makes disinfection agents less effective. Common microbial hazards in distribution systems come from contamination of human faecal pathogens and parasites which enter the systems through cross-connections, breaks, water main works, and open storage tanks.
Chemical hazards are those of disinfection by-products, leaching of piping materials and fittings, and water treatment chemicals.
Physical hazards include turbidity of water, odors, colors, scales which are buildups of materials inside the pipes from corrosions, and sediment resuspension.
There are several bodies around the world that create standards to limit hazards in the distribution systems: NSF International in North America; European Committee for Standardization, British Standards Institution and Umweltbundesamt in Europe; Japanese Standards Association in Asia; Standards Australia in Australia; and Brazilian National Standards Organization in Brazil.
Lead service lines
Lead contamination in drinking water can be from leaching of lead that was used in old water mains, service lines, pipe joints, plumbing fittings and fixtures. According to WHO, the most significant contributor of lead in water in many countries is the lead service line.
Maintenance
Internal corrosion control
Water quality deteriorate due to corrosion of metal pipe surfaces and connections in distribution systems. Pipe corrosion shows in water as color, taste and odor, any of which may cause health concerns.
Health issues relate to releases of trace metals such as lead, copper or cadmium into the water. Lead exposure can cause delays in physical and mental development in children. Long term exposure to copper may cause liver and kidney damage. High or long term exposure of cadmium may cause damage to various organs. Corrosion of iron pipes causes rusty or red water. Corrosion of zinc and iron pipes can cause metallic taste.
Various techniques can be used to control internal corrosion, for example, pH level adjustment, adjustment of carbonate and calcium to create calcium carbonate as pipe surface coating, and applying a corrosion inhibitor. For example, phosphate products that form films over pipe surfaces is a type of corrosion inhibitor. This reduces the chance of leaching of trace metals from the pipe materials into the water.
Hydrant flushing
Hydrant flushing is the scheduled release of water from fire hydrants or special flushing hydrants to purge iron and other mineral deposits from a water main. Another benefit of using fire hydrants for water main flushing is to test whether water is supplied to fire hydrants at adequate pressure for fire fighting. During hydrant flushing, consumers may notice rust color in their water as iron and mineral deposits are stirred up in the process.
Water main renewals
After water mains are in service for a long time, there will be deterioration in structural, water quality, and hydraulic performance. Structural deterioration may be caused by many factors. Metal-based pipes develop internal and external corrosion, causing the pipe walls to thin or degrade. They can eventually leak or burst. Cement-based pipes are subject to cement matrix and reinforced steel deterioration. All pipes are subject to joint failures. Water quality deterioration includes scaling, sedimentation, and biofilm formation. Scaling is the formation of hard deposits on the interior wall of pipes. This can be a by-product of pipe corrosion combined with calcium in the water, which is called tuberculation. Sedimentation is when solids settle within the pipes, usually at recesses between scaling build-ups. When there is a change in the velocity of water flow (such as sudden use of a fire hydrant), the settled solids will be stirred up, causing water to be discolored. Biofilms can develop in highly scaled and thus rough-surfaced pipes where bacteria are allowed to grow, as the higher the roughness of the interior wall, the harder it is for disinfectant to kill the bacteria on the surface of the pipe wall. Hydraulic deterioration that affects pressures and flows can be a result of other deterioration that obstructs the water flow.
When it is time for water main renewal, there are many considerations in choosing the method of renewal. This can be open-trench replacement or one of the pipeline rehabilitation methods. A few pipeline rehabilitation methods are pipe bursting, sliplining, and pipe lining.
When an in-situ rehabilitation method is used, one benefit is the lower cost, as there is no need to excavate along the entire water main pipeline. Only small pits are excavated to access the existing water main. The unavailability of the water main during the rehabilitation, however, requires building a temporary water bypass system to serve as the water main in the affected area. A temporary water bypass system (known as temporary bypass piping) should be carefully designed to ensure an adequate water supply to the customers in the project area. Water is taken from a feed hydrant into a temporary pipe. When the pipe crosses a driveway or a road, a cover or a cold patch should be put in place to allow cars to cross the temporary pipe. Temporary service connections to homes can be made to the temporary pipe. Among many ways to make a temporary connection, a common one is to connect the temporary service connection to a garden hose. The temporary pipe should also add temporary fire hydrants for fire protection.
As water main work can disturb lead service lines, which can result in elevated lead levels in drinking water, it is recommended that when a water utility plans a water main renewal project, it should work with property owners to replace lead service lines as part of the project.
See also
Water supply network
District heating for hot water distribution system
References
Supply network
Environmental engineering
Hydraulics
Supply network | Water distribution system | [
"Physics",
"Chemistry",
"Engineering",
"Environmental_science"
] | 2,577 | [
"Hydrology",
"Chemical engineering",
"Physical systems",
"Hydraulics",
"Civil engineering",
"Water industry",
"Environmental engineering",
"Fluid dynamics"
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53,085,159 | https://en.wikipedia.org/wiki/Frame%20Arms%20Girl | is a series of heavily customizable model kit girls produced by Kotobukiya, originally released in 2015 as a moé reimagining of the more traditional, equally customizable Frame Arms mecha line and acts as a sister series to the Megami Device line of more traditional, non-derivative mecha musume kits, of which the line has regularly crossed over with.
A prequel manga for the anime by Tsuneo Tsuneishi began serialization in Kadokawa Shoten's Comp Ace magazine in December 2016. An anime television series inspired by the line aired from April 3, 2017, to June 19, 2017. A recap film Frame Arms Girl: Kyakkyau Fufu na Wonderland was released on June 29, 2019.
Summary
Based on the original Frame Arms line, Frame Arms Girl features the robots from that line re-portrayed as anthropomorphic mecha musume, known as F.A. Girls for short, who can be equipped with various armor and weapon parts, including mixing and matching those from other original Kotobukiya kit lines, Frame Arms and the M.S.G accessory series included. The end result resembles a doll or figure with accessories attached, ranging from heavy armaments to articles of clothing, sold at the size of 1/1 scale for lore purposes, but translate to 1/10 by default and 1/24 scale for handscale versions when compared to the human body. The line's initial character design was illustrated by Fumikane Shimada, loosely inspired by Takayuki Yanase original Frame Arms mecha designs, but has since expanded to commission other artists to help on new F.A. Girls.
Multimedia Storyline
Characters
The following is a description of characters and their personalities that appeared in the anime and manga as opposed to their respective real life kits' instruction manuals.
A human girl who is given the job of providing data for the F.A. Girls by Factory Advance. Because her parents have business overseas, she lives alone in her apartment. As more F.A. Girls are sent to her, she slowly begins accepting them as a family.
An F.A. Girl who is sent to Ao to gather emotion data. She is a ground-based fighter who can move quickly with tank-style treads, but has a disadvantage over aerial types. It is revealed that there are many copies of her sent out to different people around the city, but Ao's is the only one that is active. She is the first F.A. Girl that Ao receives.
A bossy F.A. Girl who gets flustered easily. Equipped with wings, she specializes in aerial combat. Ao nicknames her Sty-ko. She and Baselard are sent to Ao's apartment shortly after Gourai.
An energetic and childish F.A. Girl who likes to cause mischief. Like Stylet, she is an aerial type who focuses on guided laser weapons. She and Stylet are sent to Ao's apartment shortly after Gourai.
A pair of F.A. Girls who have the same model and can be considered as sisters, given the names and to distinguish from each other. They are oddly affectionate towards each other and take pleasure in torturing others, often omitting the use of armor in favor of powerful weaponry. Ao receives them sometime after getting Gourai, Stylet, and Baselard.
An F.A. girl who, along with the Materia Sisters, is the basis of every other F.A. Girl and, according to Stylet, has no physical body and only manifests herself during certain battles to carry out her programming. She was given a physical body after Gourai and Jinrai defeated her, loaded with the data generated during their battle. She shows very little emotion compared to the other F.A. Girls, and has the ability to alter her appearance in battle. She is the seventh F.A. Girl that Ao receives.
A proud and traditionalist F.A. Girl who has a particularly obsession with the Sengoku period and specializes in ninja techniques. She is the sixth F.A. Girl that Ao receives.
A powerful F.A. Girl who gave Gourai her first defeat, causing Gourai to improve further. Ao nicknames her Hres. She is arrogant, a little antagonistic, and loves to battle. Factory Advance later provides her with an upgrade that alters her appearance, but this unintentionally corrupts her. After Gourai defeats her, she is freed from her corruptive state and is allowed to stay with Ao, developing a much nicer personality afterwards. She is the last F.A. Girl that Ao receives.
Ao's best friend, who is obsessed with model kits and often provides Ao with the latest parts after finding out about the F.A. Girls. She is also a moé reimagining of Kotobukiya, the real-life company behind Frame Arms Girls.
Guriko
A mysterious girl that Ao meets at the park that she used to visit when she was a child, who guides Ao to a time capsule that she buried there. She disappears afterwards. A doll version of her is found inside of the time capsule, which implies that she is a vision from Ao's past.
Jyuden-kun
Every F.A. Girl is accompanied by these small robots who are tasked with recharging them and preparing them for battles. They can also act as a chair or as a bed for them, and can serve as a communication device.
Sleipni-taro
It was originally a cleaning robot that experiences malfunctions. After it was repaired, the robot was also given an upgrade as well as artificial intelligence. It usually serves as a means of transportation for the F.A. Girls and as a rideable toy by Baselard.
Nipako
Godhand's mascot. In the show, she cameos as a nipper tsukumogami who haunts Ao's school after a girl misused a pair of plastic cutting nippers on metal, being the GodHand SPN-120 Ultimate, a nipper regarded as a glass cannon for its highest quality cuts in the plamo hobby and highest level of fragility on misuse. Nipako haunts the school at night, possessing the very same nippers that broke. After cutting off an unneeded fragment that was to be cleaned from Gourai's armor, the nippers return to normal and is taken back to Ao's place as a souvenir while Nipako watches them with happiness, implying that she is now at peace knowing that she will be handled with care in the future.
Innocentia
A newly developed F.A. Girl who was teased at the end of the final episode. Her abilities and future remain unknown and she is unvoiced within the anime.
Manga
A manga prequel written by Kotobukiya and illustrated by Tsuneo Tsuneishi, titled , began serialization in Kadokawa Shoten's Comp Ace magazine from December 26, 2016.
Anime
A 12-episode anime television adaption aired on Tokyo MX between April 3, 2017, and June 19, 2017, also airing on BS11 and AT-X. The anime was directed by Keiichiro Kawaguchi at studios Zexcs and Studio A-Cat with scripts written by Deko Akao and the music is produced by Keigo Hoashi and Kakeru Ishihama. Sentai Filmworks have licensed it for home video and digital release. The series was streamed by the Anime Network. The opening theme is "Tiny Tiny" by Rie Murakawa while the ending theme is "Fullscratch Love", performed by the series' voice actresses.
The anime follows a girl named Ao who is sent a prototype F.A. Girl known as Gourai and is tasked with helping her gather data on both battle and emotions. The two soon encounter more F.A. Girls sent by Factory Advance, the company who created them, who Gourai battles against while also having various adventures alongside. Any F.A. Girls that Gourai defeats are allowed to stay with her and Ao.
A film titled Frame Arms Girl: Kyakkyau Fufu na Wonderland has been announced. It was revealed that the film will be a compilation film with new added footage. The film premiered on June 29, 2019.
Note
See also
Arcanadea, another plastic model series created by Kotobukiya
Busou Shinki
Little Battlers Experience
Alice Gear Aegis
References
External links
Frame Arms Girl Official on YouTube
2016 manga
Kadokawa Shoten manga
Mecha anime and manga
Scale modeling
Seinen manga
Sentai Filmworks
Studio A-Cat
Tokyo MX original programming
Zexcs | Frame Arms Girl | [
"Physics"
] | 1,803 | [
"Scale modeling"
] |
53,089,397 | https://en.wikipedia.org/wiki/Photolabile%20protecting%20group | A photolabile protecting group (PPG; also known as: photoremovable, photosensitive, or photocleavable protecting group) is a chemical modification to a molecule that can be removed with light. PPGs enable high degrees of chemoselectivity as they allow researchers to control spatial, temporal and concentration variables with light. Control of these variables is valuable as it enables multiple PPG applications, including orthogonality in systems with multiple protecting groups. As the removal of a PPG does not require chemical reagents, the photocleavage of a PPG is often referred to as "traceless reagent processes", and is often used in biological model systems and multistep organic syntheses. Since their introduction in 1962, numerous PPGs have been developed and utilized in a variety of wide-ranging applications from protein science to photoresists. Due to the large number of reported protecting groups, PPGs are often categorized by their major functional group(s); three of the most common classifications are detailed below.
Historical introduction
The first reported use of a PPG in the scientific literature was by Barltrop and Schofield, who in 1962 used 253.7 nm light to release glycine from N-benzylglycine. Following this initial report, the field rapidly expanded throughout the 1970s as Kaplan and Epstein studied PPGs in a variety of biochemical systems. During this time, a series of standards for evaluating PPG performance was compiled. An abbreviated list of these standards, which are commonly called the Lester rules, or Sheehan criteria are summarized below:
In biological systems, the protected substrate, as well as the photoproducts should be highly soluble in water; in synthesis, this requirement is not as strict
The protected substrate, as well as the photoproducts should be stable in the photolysis environment
Separation of the PPG should exhibit a quantum yield greater than 0.10
Separation of the PPG should occur through a primary photochemical process
The chromophore should absorb incident light with reasonable absorptivity
The excitation wavelength of light should be greater than 300 nm
The media and photoproducts should not absorb the incident light
A general, high-yield synthetic procedure should exist for attaching the PPG to an unprotected substrate
The protected substrate and the photoproducts should be easily separated
Main classifications
Nitrobenzyl-based PPGs
Norrish Type II mechanism
Nitrobenzyl-based PPGs are often considered the most commonly used PPGs. These PPGs are traditionally identified as Norrish Type II reaction as their mechanism was first described by Norrish in 1935. Norrish elucidated that an incident photon (200 nm < λ < 320 nm) breaks the N=O π-bond in the nitro-group, bringing the protected substrate into a diradical excited state. Subsequently, the nitrogen radical abstracts a proton from the benzylic carbon, forming the aci-nitro compound. Depending on pH, solvent and the extent of substitution, the aci-nitro intermediate decays at a rate of roughly 102–104 s−1. Following resonance of the π-electrons, a five-membered ring is formed before the PPG is cleaved yielding 2-nitrosobenzaldehyde and a carboxylic acid.
Overall, nitrobenzyl-based PPGs are highly general. The list of functional groups that can be protected include, but are not limited to, phosphates, carboxylates, carbonates, carbamates, thiolates, phenolates and alkoxides. Additionally, while the rate varies with a number of variables, including choice of solvent and pH, the photodeprotection has been exhibited in both solution and in the solid-state. Under optimal conditions, the photorelease can proceed with >95% yield. Nevertheless, the photoproducts of this PPG are known to undergo imine formation when irradiated at wavelengths above 300 nm. This side product often competes for incident radiation, which may lead to decreased chemical and quantum yields.
Common modifications
In attempts to raise the chemical and quantum yields of nitrobenzyl-based PPGs, several beneficial modifications have been identified. The largest increase in quantum yield and reaction rate can be achieved through substitution at the benzylic carbon. However, potential substitutions must leave one hydrogen atom so the photodegradation can proceeded uninhibited.
Additional modifications have targeted the aromatic chromophore. Specifically, multiple studies have confirmed that the use of a 2,6-dinitrobenzyl PPG increases reaction yield. Additionally, depending on the leaving group, the presence of a second nitro-group may nearly quadruple the quantum yield (e.g. Φ = 0.033 to Φ = 0.12 when releasing a carbonate at 365 nm). While one may credit the increase in efficiency to the electronic effects of the second nitro group, this is not the case. Analogous systems with a 2-cyano-6-nitrobenzyl PPG exhibit similar electron-withdrawing effects, but do not provide such a large increase in efficiency. Therefore, the increase in efficiency is likely due to the increased probability of achieving the aci-nitro state; with two nitro groups, an incoming photon will be twice as likely to promote the compound into an excited state.
Finally, changing the excitation wavelength of the PPG may be advantageous. For example, if two PPGs have different excitation wavelengths one group may be removed while the other is left in place. To this end, several nitrobenzyl based PPGs display additional functionality. Common modifications include the use of 2-nitroveratryl (NV) or 6-nitropiperonylmethyl (NP). Both of these modifications induced red-shifting in the compounds' absorption spectra.
Carbonyl-based PPGs
Phenacyl PPGs
The phenacyl PPG is the archetypal example of a carbonyl-based PPG. Under this motif, the PPG is attached to the protected substrate at the αβ-carbon, and can exhibit varied photodeprotection mechanisms based on the phenacyl skeleton, substrate identify and reaction conditions. Overall, phenacyl PPGs can be used to protect sulfonates, phosphates, carboxylates and carbamates.
As with nitrobenzyl-based PPGs, several modifications are known. For example, the 3',5'-dimethoxybenzoin PPG (DMB) contains a 3,5-dimethoxyphenyl substituent on the carbonyl's α-carbon. Under certain conditions, DMB has exhibited quantum yields as high as 0.64. Additionally, the p-hydroxyphenacyl PPG (pHP) has been designed to react through a photo-Favorskii rearrangement. This mechanism yields the carboxylic acid as the exclusive photoproduct; the key benefit of the pHP PPG is the lack of secondary photoreactions and the significantly different UV absorption profiles of the products and reactants. While the quantum yield of the p-hydroxyphenacyl PPG is generally in the 0.1-0.4 range, it can increase to near unity when releasing a good leaving group such as a tosylate. The photoextrusion of the leaving group from the pHP PPG is so effective, that it also releases even poor nucleofuges such as amines (with the quantum yield in the 0.01-0.5 range, and dependent on solution pH). The Additionally, photorelease occurs on the nanosecond timeframe, with krelease > 108 s−1.
The o-hydroxyphenacyl PPG has been introduced as an alternative with absorption band shifted closer towards the visible region, however it has slightly lower quantum yields of deprotection (generally 0.1-0.3) due to excited state proton transfer available as an alternative deactivation pathway.
The phenacyl moiety itself contains one chiral carbon atom in the backbone. The protected group (leaving group) is not directly attached to this chiral carbon atom, however has been shown to be able to work as a chiral auxiliary directing approach of a diene to a dienophile in a stereoselective thermal Diels–Alder reaction. The auxiliary is then removed simply upon irradiation with UV light.
Photoenolization through γ-hydrogen abstraction
Another family of carbonyl-based PPGs exists that is structurally like the phenacyl motif, but which reacts through a separate mechanism. As the name suggests, these PPGs react through abstraction of the carbonyl's γ-hydrogen. The compound is then able to undergo a photoenolization, which is mechanistically like a keto-enol tautomerization. From the enol form, the compound can finally undergo a ground-state transformation that releases the substrate. The quantum yield of this mechanism directly corresponds to the ability of the protected substrate to be a good leaving group. For good leaving groups, the rate-determining step is either hydrogen abstraction or isomerization; however, if the substrate is a poor leaving group, release is the rate-determining step.
Benzyl-based PPGs
Barltrop and Schofield first demonstrated the use of a benzyl-based PPG, structural variations have focused on substitution to the benzene ring, as well as extension of the aromatic core. For example, insertion of a m,m’-dimethoxy substituent was shown to increase the chemical yield ~75% due to what has been termed the “excited state meta effect.” However, this substitution is only able to release good leaving groups such as carbamates and carboxylates. Additionally, the addition of an o-hydroxy group enables the release of alcohols, phenols and carboxylic acids due to the proximity of the phenolic hydroxy to the benzylic leaving group. Finally, the carbon skeleton has been expanded to include PPGs based on naphthalene, anthracene, phenanthrene, pyrene and perylene cores, resulting in varied chemical and quantum yields, as well as irradiation wavelengths and times.
Applications
Use in total synthesis
Despite their many advantages, the use of PPGs in total syntheses are relatively rare. Nevertheless, PPGs’ "orthogonality" to common synthetic reagents, as well as the possibility of conducting a "traceless reagent process", has proven useful in natural product synthesis. Two examples include the syntheses of ent-Fumiquinazoline and (-)-diazonamide A. The syntheses required irradiation at 254 and 300 nm, respectively.
Photocaging
Protecting a substrate with a PPG is commonly referred to as "photocaging." This term is especially popular in biological systems. For example, Ly et al. developed a p-iodobenzoate-based photocaged reagent, which would experience a homolytic photoclevage of the C-I bond. They found that the reaction could occur with excellent yields, and with a half-life of 2.5 minutes when a 15 W 254 nm light source was used. The resulting biomolecular radicals are necessary in many enzymatic processes. As a second example, researchers synthesized a cycloprene-modified glutamate photocaged with a 2-nitroveratrol-based PPG. As it is an excitatory amino acid neurotransmitter, the aim was to develop a bioorthagonal probe for glutamate in vivo. In a final example, Venkatesh et al. demonstrated the use of a PPG-based photocaged therapeutic. Their prodrug, which released one equivalent of caffeic acid and chlorambucil upon phototriggering, showed reasonable biocompatibility, cellular uptake and photoregulared drug release in vitro.
Photoresists
During the 1980s, AT&T Bell Laboratories explored the use of nitrobenzyl-based PPGs as photoresists. Over the course of the decade, they developed a deep UV positive-tone photoresist where the protected substrate was added to a copolymer of poly(methyl methacrylate) and poly(methacrylic acid). Initially, the blend was insoluble. However, upon exposure to 260 ± 20 nm light, the PPG would be removed yielding 2-nitrosobenzaldehyde and a carboxylic acid that was soluble in aqueous base.
Surface modification
When covalently attached to a surface, PPGs do not exhibit any surface-induced properties (i.e. they behave like PPGs in solution, and do not exhibit any new properties because of their proximity to a surface). Consequently, PPGs can be patterned on a surface and removed in manner analogous to lithography to create a multifunctionalized surface. This process was first reported by Solas in 1991; protected nucleotides were attached to a surface and spatially-resolved single stranded polynucleotides were generated in a step-wise “grafting from” method. In separate studies, there have been multiple reports of using PPGs to enable the selective separation of blocks within block-copolymers to expose fresh surfaces. Furthermore, this surface patterning method has since been extended to proteins. Caged etching agents (such as hydrogen fluoride protected with 4-hydroxyphenacyl) allows to etch only surfaces exposed to light.
Gels
Various PPGs, often featuring the 2-nitrobenzyl motif, have been used to generate numerous gels. In one example, researchers incorporated PPGs into a silica-based sol-gel. In a second example, a hydrogel was synthesized to include protected Ca2+ ions. Finally, PPGs have been utilized to cross-link numerous photodegradable polymers, which have featured linear, multi-dimensional network, dendrimer, and branched structures.
References
Protecting groups
Photochemistry | Photolabile protecting group | [
"Chemistry"
] | 2,977 | [
"Protecting groups",
"Functional groups",
"nan",
"Reagents for organic chemistry"
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53,089,431 | https://en.wikipedia.org/wiki/Thierry%20Legault | Thierry Legault (born 1962) is a French amateur astronomer, specializing in astrophotography.
An engineer by trade, he started astrophotography in 1993 and resorted to CCD cameras to photograph the deep sky. He then joined the Association des utilisateurs de détecteurs electroniques (l'AUDE), which aims to develop astronomical observation based on electronic detectors. In 1994, along with Christian Buil, he participated in a mission at the Pic du Midi Observatory on the collision of comet Shoemaker-Levy 9 with Jupiter and launched himself into planetary photography. He is the first amateur to have shown on his photographs the division of Encke on the rings of Saturn.
His photographs of the deep sky, the planets, the Moon and the Sun (eclipses and HA images) are published in numerous astronomical journals. Its image of the solar transit of the International Space Station (ISS) and the Space Shuttle Atlantis was presented on CNN in the introduction of the weather report of Femi Oke of October 6, 2006. He photographed the transit of the Space Shuttle Atlantis with the Hubble Space Telescope during its service mission in May 2009. He photographed the transit of the International Space Station in front of the sun during the partial eclipse of January 4, 2011. On June 6, 2012, during the transit of Venus, he traveled to Australia to photograph Venus and the Hubble Space Telescope in front of the Sun.
The International Astronomical Union gave its name to (19458 Legault) (1998 HE8), an asteroid of the main belt discovered in 1998 by Michel Bœuf. In 1999, the Société astronomique de France awarded him the Marius Jacquemetton Prize, which rewards "a remarkable astronomical work in the field of popularization as well as in the practice of amateur astronomy".
He published Le grand atlas de la Lune (The Grand Atlas of the Moon) with Serge Brunier at Éditions Larousse in 2004 and in 2006, Astrophotography, which received the Special Jury Prize of the Festival d'astronomie de Haute-Maurienne 2007.
References
External links
astrophoto.fr
Thierry Legault's personal page
21st-century French astronomers
1962 births
Living people
20th-century French astronomers
Astrophotographers
French photographers | Thierry Legault | [
"Astronomy"
] | 467 | [
"People associated with astronomy",
"Astrophotographers"
] |
53,089,666 | https://en.wikipedia.org/wiki/Kappa%20Lupi | The Bayer designation κ Lupi (Kappa Lupi) is shared by two star systems in the constellation Lupus:
κ1 Lupi (HD 134481)
κ2 Lupi (HD 134482)
According to Eggleton and Tokovinin (2008), the pair form a binary system with an angular separation of .
References
Lupi, Kappa
Lupus (constellation) | Kappa Lupi | [
"Astronomy"
] | 80 | [
"Constellations",
"Lupus (constellation)"
] |
53,089,755 | https://en.wikipedia.org/wiki/Xi%20Lupi | The Bayer designation ξ Lupi (Xi Lupi) is shared by two star systems in the constellation Lupus:
ξ1 Lupi (HD 142629)
ξ2 Lupi (HD 142630)
Listed in the Washington Double Star Catalog as WDS J15569-3358, this double star most likely forms a wide binary star system. As of epoch 2004.38, the pair had an angular separation of along a position angle of . The difference in visual magnitude between the two stars is .
References
Lupi, Xi
Lupus (constellation) | Xi Lupi | [
"Astronomy"
] | 116 | [
"Constellations",
"Lupus (constellation)"
] |
53,089,759 | https://en.wikipedia.org/wiki/Xplore%20Technologies | Xplore Technologies is a publicly traded, designer, marketer and manufacturer of rugged tablets. The company was founded in 1996 and is based in Austin, Texas. In 2015, Xplore Technologies purchased assets of Motion Computing making it one of the top companies in the rugged tablet PC market. The company's products are primarily used by field service personnel, factory workers and military personnel. Xplore Technologies products are built to satisfy MIL-STD-810G and HAZLOC compliant ATEX standards, as well as Ingress Protection (IP) ratings.
History
Xplore Technologies was founded in Ontario, Canada in 1996 and began selling devices in 1998. The company was listed on the Toronto Stock Exchange in June 1998. In 2003, Xplore Technologies announced that it was relocating its corporate headquarters to Austin, Texas. The company filed to change its jurisdiction from Canada to Delaware in 2006. In July 2012, after being traded over-the-counter since leaving the TSX, the company filed for an IPO with the SEC and was listed on the Nasdaq stock exchange. In March 2015, Xplore Technologies raised $12 million when it sold an additional 2 million shares of common stock. In April 2015, the company bought assets of Motion Computing Inc. for $16 million. On July 5, 2018, Zebra Technologies announced its intent to acquire Xplore Technologies for roughly $90 million.
See also
References
Computer companies of the United States
Computer hardware companies
Computer systems companies
Companies based in Austin, Texas
Companies established in 1996 | Xplore Technologies | [
"Technology"
] | 307 | [
"Computer hardware companies",
"Computer systems companies",
"Computers",
"Computer systems"
] |
53,089,821 | https://en.wikipedia.org/wiki/Tau%20Lupi | The Bayer designation τ Lupi (Tau Lupi) is shared by two star systems in the constellation Lupus:
τ1 Lupi (HD 126341)
τ2 Lupi (HD 126354)
Lupi, Tau
Lupus (constellation) | Tau Lupi | [
"Astronomy"
] | 54 | [
"Constellations",
"Lupus (constellation)"
] |
53,089,884 | https://en.wikipedia.org/wiki/Phi%20Lupi | The Bayer designation φ Lupi (Phi Lupi) is shared by two star systems in the constellation Lupus:
φ1 Lupi (HD 136422)
φ2 Lupi (HD 136664)
Lupi, Phi
Lupus (constellation) | Phi Lupi | [
"Astronomy"
] | 54 | [
"Constellations",
"Lupus (constellation)"
] |
53,090,036 | https://en.wikipedia.org/wiki/Al-Wabkanawi | Shams al-Munajjim Muhammad ibn Ali al-Wabkanawi was a 14th century Persian astronomer. He is the author of a zij, the . From his name it is known he originated from Wābkana, Bukhara, but little else is known of his life. His zij is extant in four manuscripts. His book is written in Persian, even though its title is in Arabic. Another extant book by him, Kitāb-i maʿrifat-i usṭurlāb-i shamālī is also written in Persian.
References
Sources
People from Bukhara
14th-century Iranian astronomers
Astronomers of the medieval Islamic world | Al-Wabkanawi | [
"Astronomy"
] | 137 | [
"Astronomers",
"Astronomer stubs",
"Astronomy stubs"
] |
53,090,510 | https://en.wikipedia.org/wiki/Iota%20Muscae | The Bayer designation ι Muscae (Iota Muscae) is shared by two stars in the constellation Musca:
ι1 Muscae
ι2 Muscae
Muscae, Iota
Musca | Iota Muscae | [
"Astronomy"
] | 45 | [
"Musca",
"Constellations"
] |
53,091,648 | https://en.wikipedia.org/wiki/Jos%C3%A9%20Antonio%20Sosa | José Antonio Sosa Diaz-Saavedra (born 8 May 1957, Las Palmas) is a Spanish architect, university professor and researcher. He is a member of the Royal Canarian Academy of Fine Arts of St. Michael Archángel.
Early life and education
José Antonio Sosa Díaz-Saavedra was brought up in a family with an interest in art and history, especially in relation to the Canary Islands. As a result, he was encouraged to study architecture, graduating from the Superior Technical School of Architecture of Madrid in 1981. In 1994, he earned a Ph.D. at the School of Architecture, University of Las Palmas de Gran Canaria.
Teaching
After completing his doctoral studies, he obtained the chair of Architectural Projects in the Department of Graphic Expression and Architectural Projects of the EALPGC, School of Architecture of Las Palmas de Gran Canaria, where he has been since 1983.
In the year 2000 he was visiting scholar and taught in the Department of Architecture, belonging to the Graduate School of Design, Harvard University, he has also participated as a jury in several universities among which is the Swiss Federal Institute of Technology, ETH (Studio Basel).
In 2015 he joined the University Institute of Intelligent Systems and Numerical Applications in Engineering of the ULPGC, University of Las Palmas de Gran Canaria.
Main architecture contributions
José Antonio Sosa has been the main proponent of modern architectural development in the early twentieth century in the Canary Islands and Spain, promoting its place in the history of urban and cultural heritage. As a result, he was appointed a member of the Royal Canarian Academy of Fine Arts of St. Michael Archángel.
In 1996 Professor Sosa joined his studio with that of , creating the Nred Arquitectos Group, which has since worked on such projects as the City of Justice (New Law Courts Headquarters) and the rehabilitation of the Town Halls (Town Hall Houses) of Las Palmas de Gran Canaria.
Since 2011, he has founded a new studio for architecture and urban planning together with Evelyn Alonso Rohner.
In 2015 José Antonio Sosa is the managing editor of the Arquiatesis editorial line for the publication and publication of theses and research works in architecture.
Individual and Collective exhibitions
Sosa, has participated in the following exhibitions:
1997 "Hard & Soft" Eight Floor Gallery, (New York), USA
2003 "One is always Two", Professional Architects Association (Tenerife), Spain
2003 "Spaces for intimacy" Hall los Aljibes (Lanzarote), Spain
2004 "DakÁrt Biennial" (Dakar), Senegal
2005 "Sao Paulo Architecture Biennial", Brazil.
2005 "Architecture for Justice" COAC. (Madrid), Spain
2007 "Individual exhibition": Nred Architects, Literary Cabinet. (Las Palmas), Spain
2007 "Regeneration Strategy", Nacional Library. (Pekín), China
2007 "Refabricating City "Shenzhen & Hong Kong, Biennial of Urban Planning and Architecture. (Hong Kong), China
2007 "Xisi Bei street". (Beijing), China
2008 "Gallery AEDES". (Berlin), Germany
2008" Sustainable Building. (Melbourne), Australia
2007–2009 "Biennial of Art, Architecture and landscape of Canarias". (Las Palmas), Spain
2009 "Object Art" Manuel Ojeda Gallery. (Las Palmas), Spain
2010–2011 "A city called Spain". (Athens-Moscow), Greece-Russia
2015–2016 Exhibition at the MAXXI (Museo Nazionale delle Arti del XXI Secolo in Rome), Italy.
2017 "In process". Exhibition of architectural models by Alonso-Sosa in the Saro León Gallery. (Las Palmas), Spain.
Acknowledgments
Academy Member
Admission of José Antonio Sosa Díaz-Saavedra into the Real Academia de Bellas Artes de Canarias of San Miguel Arcangel (Royal Canarian Academy of Fine Arts of St. Michael Archángel.), 2014.
Awards
Professor Sosa has been awarded in the following competitions:
2006 First prize, The Venegas Public Square and Underground Car Park
2005 First prize, Puerto del Rosario Waterfront
2005 First prize, La Regenta Art Center
2004 First prize, the City of Justice (New Law Courts Headquarter) in Las Palmas.
2002 First prize, The Rehabilitation (building restoration) of the Town Hall Las Palmas, Gran Canaria
1997 First prize, The Rehabilitation (building restoration) of the Literary Cabinet "Design and Ideas"
2008 Third prize,The Madrid. Slaughterhouse
2008 First prize, Rehabilitation, Consistorial Houses of the Palmas de Gran Canaria (Melbourne Sustainable Building)
2008 First Accésit, For Architectural Renovation (building restoration) of the Old Tabakalera in Donostia-San Sebastián
2012 First prize, Railway Station of Playa del Inglés
2013 Second prize, Station-20, Sophia, Bulgaria
2016 First prize, A House in a Garden, Gran Canaria
Buildings
Some of them are:
2003 Loyola`s Foundation Administrative building, Spain
2003 The Elongated House. (Gran Canaria), Spain (In collaboration with Miguel Santiago),
2004 The Hidden House. (Gran Canaria), Spain
2008 Rehabilitación (building restoration) Town Hall of (Las Palmas), Spain (In collaboration with Magüi González)
2010 Black Pavilion. (Las Palmas), Spain
2010 Art Center, La Regenta. (Las Palmas), Spain
2011 The Z House. (Gran Canaria), Spain
2011 Station-20. (Sophia), Bulgaria
2012 Railway Station of Playa del Inglés. (Las Palmas), Spain
2012 The City of Justice,"New Law Courts Headquarter". (Las Palmas), Spain. (Jointly with Magüi González y Miguel Santiago)
2012 Central Library of Helsinki, Finland (Jointly with Evelyn Alonso Rohner)
2014 Philologicum of Munich, Germany (Jointly with Evelyn Alonso Rohner)
2014 The Loft Apartment, emblematic house intervention and renewal. (Las Palmas), Spain (Jointly with Evelyn Alonso Rohner).
2014 Total building rehabilitation Buganvilla Apartments. (Gran Canaria), Spain. (Jointly with Evelyn Alonso Rohner).
2015–16 Industrial building renewal, Group Volkswagen franchisee “Majuelos” La Laguna, Tenerife , Spain. (Jointly with Evelyn Alonso Rohner)
2016–17 Rehabilitation of the Industrial and Commercial Building “La Loza” (Las Palmas), Spain. (Jointly with Evelyn Alonso Rohner).
Publications
Books
Sosa has published the following texts:
En Proceso, José Antonio Sosa, Evelyn Alonso, David Alemán, Vidania Báez, Álvaro del Amo, Carlos Marrero, 2017
Confluences. José Antonio Sosa, Magūi González, Miguel Santiago, Evelyn Alonso, Author: Ana Maria Torres, Publisher: Cinisello Balsamo, Milano Silvana,2015,
Paisajes de Encuentro. José Antonio Sosa,2007
Redes. José Antonio Sosa,2007
Corralejo. José Antonio Sosa,2007
Nred Arquitectos, Compilación. José Antonio Sosa, Maria L. Gonzalez, Graham Thomson,Clara Jiménez, Publisher: Literary Cabinet of Las Palmas, 2006
Cultivo. José Antonio Sosa, Eva Alfonso, Hector Sanchez 2005
Hibridaciones. José Antonio Sosa, Eva Alfonso, Hector Sanchez 2005
Aprendiendo del Territorio. José Antonio Sosa, Pedro Nicolas Romera, 2004
Arquitectura Moderna y Turismo: 1925–1965: Proceedings IV Congreso DOCOMOMO Iberian Foundation, José Antonio Sosa Díaz-Saavedra, Carmen Jordá Such, Nuno Portas, DOCOMOMO Iberian Foundation of Valencia, 2003
La Casa del Marino, Las Palmas de Gran Canaria, 1958–1964: José Antonio Sosa, Miguel Martín-Fernández, Colegio de Arquitectos de Almería, 2002.
Contextualismo y Abstracción. Interrelaciones entre suelo, paisaje y arquitectura,1994
Articles
Among them are:
Introspecciones Elocuentes. José Antonio Sosa Díaz-Saavedra Annals of the Royal Canarian Academy of Fine Arts of San Miguel Arcángel..: RACBA, ISSN 2174-1484, Nº. 8, 2015, págs. 165-168
Naturalezas Abstractas. José Antonio Sosa Díaz-Saavedra, Annals of the Royal Canarian Academy of Fine Arts of San Miguel Arcángel.: RACBA, ISSN 2174-1484, Nº. 7, 2014, págs. 143-152
Armazones. José Antonio Sosa Díaz-Saavedra, Transfer, ISSN 1695-1778, Nº. 5, 2003, pág. 107
Condiciones de Contorno. Official Magazine, Colegio de Arquitectos de Madrid (COAM), ISSN 0004-2706, Nº. 345, 2006, págs.
Espacios sin Sombra. José Antonio Sosa Díaz-Saavedra, Official Magazine, Colegio de Arquitectos de Madrid (COAM), ISSN 0004-2706, Nº. 330, 2003, págs. 48-5
Una Nube en una Jaula, (La Maison Suspendu). José Antonio Sosa Díaz-Saavedra y, Paul Nelson Official Magazine, Colegio de Arquitectos de Madrid (COAM), ISSN 0004-2706, Nº. 328, 2002, págs. 20-27
Capó y Envolventes. José Antonio Sosa Díaz-Saavedra y Magüi González, Basa, ISSN 0213-0653, Nº. 24, 2001, págs. 138-145
Coello de Portugal en Canarias. José Antonio Sosa Díaz-Saavedra, Basa, ISSN 0213-0653, Nº. 22, 2000, págs. 20-41
Constructores de Ambientes. del mat-building a la lava programática, José Antonio Sosa Díaz-Saavedra Quaderns 220, 1998
Vacío: deriva y captura. José Antonio Sosa Díaz-Saavedra y Magüi González, Basa, ISSN 0213-0653, Nº. 19, 1996, págs. 68-71
El Cabildo Racionalista de Gran Canaria "Alejandro de la Sota" y el proyecto para su ampliación. José Antonio Sosa Díaz-Saavedra, Magui González, Official Magazine, Colegio de Arquitectos de Madrid (COAM), ISSN 0004-2706, Nº. 300, 1994, págs. 42-48
El Paisaje como Premisa de Proyecto en el Movimiento Moderno. José Antonio Sosa Díaz-Saavedra, Félix J. Bordes Caballero), Basa, ISSN 0213-0653, Nº. 16, 1994, págs. 98-103
Doce Apartamentos en Playa del Inglés. Playa del Inglés "Gran Canaria", José Antonio Sosa Díaz-Saavedra y Francisco Campos, Basa, ISSN 0213-0653, Nº. 10, 1989, págs. 98-101
Ideas y Obras. José Antonio Sosa Díaz-Saavedra, Basa, ISSN 0213-0653, Nº. 2, 1984 (Book dedicated to: Eduardo Westerdahl), págs. 33-36
References
External links
SIANI
University of Las Palmas de Gran Canaria
El Catedrático José Antonio Sosa Díaz-Saavedra, numerario de la Real Academia de Bellas Artes
Alonso & Sosa Architects
1957 births
Living people
People from Las Palmas
Spanish architects
Modernist architects
Spanish urban planners
Urban designers
Landscape architecture
Technical University of Madrid alumni
University of Las Palmas de Gran Canaria alumni | José Antonio Sosa | [
"Engineering"
] | 2,493 | [
"Landscape architecture",
"Architecture"
] |
53,091,780 | https://en.wikipedia.org/wiki/NGC%20398 | NGC 398 is a lenticular galaxy located in the constellation Pisces. It was discovered on October 28, 1886, by Guillaume Bigourdan. It was described by Dreyer as "very faint, very small, stellar."
References
External links
0398
18861028
Pisces (constellation)
004090 | NGC 398 | [
"Astronomy"
] | 68 | [
"Pisces (constellation)",
"Constellations"
] |
53,091,827 | https://en.wikipedia.org/wiki/NGC%20399 | NGC 399 is a barred spiral galaxy located in the constellation Pisces. It was discovered on October 7, 1874, by Lawrence Parsons. It was described by Dreyer as "very faint, small, round."
References
External links
0399
18741007
Pisces (constellation)
Barred spiral galaxies
004096 | NGC 399 | [
"Astronomy"
] | 69 | [
"Pisces (constellation)",
"Constellations"
] |
53,091,832 | https://en.wikipedia.org/wiki/Flavidoporia%20pulvinascens | Flavidoporia pulvinascens is a species of crust fungus that is found in Europe. Czech mycologist Albert Pilát originally described the fungus in 1953 as a species of Poria.
References
Fomitopsidaceae
Fungi described in 1953
Fungi of Europe
Fungus species | Flavidoporia pulvinascens | [
"Biology"
] | 59 | [
"Fungi",
"Fungus species"
] |
53,091,909 | https://en.wikipedia.org/wiki/NGC%20407 | NGC 407 is an edge-on spiral or lenticular galaxy located in the constellation Pisces. It was discovered on September 12, 1784, by William Herschel. It was described by Dreyer as "very faint, very small, southwestern of 2.", the other being NGC 410.
References
External links
0407
17840912
Pisces (constellation)
Discoveries by William Herschel
Spiral galaxies
004190 | NGC 407 | [
"Astronomy"
] | 88 | [
"Pisces (constellation)",
"Galaxy stubs",
"Astronomy stubs",
"Constellations"
] |
53,091,932 | https://en.wikipedia.org/wiki/NGC%20408 | NGC 408 is a star located in the constellation Pisces. It was discovered on October 22, 1867, by Herman Schultz. It was described by Dreyer as "very faint, very small, (WH) II 220 eight seconds of time to east.", WH II 220 being NGC 410.
See also
List of NGC objects (1–1000)
Pisces (constellation)
References
External links
SEDS
0408
18671022
Pisces (constellation)
Discoveries by Herman Schultz (astronomer) | NGC 408 | [
"Astronomy"
] | 107 | [
"Pisces (constellation)",
"Constellations"
] |
53,091,972 | https://en.wikipedia.org/wiki/NGC%20409 | NGC 409 is an elliptical galaxy located in the constellation Sculptor. It was discovered on November 29, 1837 by John Herschel. It was described by Dreyer as "extremely faint, small, round, very small (faint) star near."
See also
List of NGC objects (1–1000)
References
External links
SEDS
0409
18371129
Sculptor (constellation)
Elliptical galaxies
Discoveries by John Herschel
004132 | NGC 409 | [
"Astronomy"
] | 88 | [
"Constellations",
"Sculptor (constellation)"
] |
53,092,613 | https://en.wikipedia.org/wiki/Treatise%20on%20Analysis | Treatise on Analysis is a translation by Ian G. Macdonald of the nine-volume work Éléments d'analyse on mathematical analysis by Jean Dieudonné, and is an expansion of his textbook Foundations of Modern Analysis. It is a successor to the various Cours d'Analyse by Augustin-Louis Cauchy, Camille Jordan, and Édouard Goursat.
Contents and publication history
Volume I
The first volume was originally a stand-alone graduate textbook with a different title. It was first written in English and later translated into French, unlike the other volumes which were first written in French. It has been republished several times and is much more common than the later volumes of the series.
The contents include
Chapter I: Sets
Chapter II Real numbers
Chapter III Metric spaces
Chapter IV The real line
Chapter V Normed spaces
Chapter VI Hilbert spaces
Chapter VII Spaces of continuous functions
Chapter VIII Differential calculus (This uses the Cauchy integral rather than the more common Riemann integral of functions.)
Chapter IX Analytic functions (of a complex variable)
Chapter X Existence theorems (for ordinary differential equations)
Chapter XI Elementary spectral theory
Volume II
The second volume includes
Chapter XII Topology and topological algebra
Chapter XIII Integration
Chapter XIV Integration in locally compact groups
Chapter XV Normed algebras and spectral theory
Volume III
The third volume includes chapter XVI on differential manifolds and chapter XVII on distributions and differential operators.
Volume IV
The fourth volume includes
Chapter XVIII Differential systems
Chapter XIX Lie groups
Chapter XX Riemannian geometry
Volume V
Volume V consists of chapter XXI on compact Lie groups.
Volume VI
Volume VI consists of chapter XXII on harmonic analysis (mostly on locally compact groups)
Volume VII
Volume VII consists of the first part of chapter XXIII on linear functional equations. This chapter is considerably more advanced than most of the other chapters.
Volume VIII
Volume VIII consists of the second part of chapter XXIII on linear functional equations.
Volume IX
Volume IX contains chapter XXIV on elementary differential topology. Unlike the earlier volumes there is no English translation of it.
Volume X
Dieudonne planned a final volume containing chapter XXV on nonlinear problems, but this was never published.
References
Mathematics books
Mathematical analysis
Treatises | Treatise on Analysis | [
"Mathematics"
] | 437 | [
"Mathematical analysis"
] |
53,093,752 | https://en.wikipedia.org/wiki/Wolfgang%20Fink | Wolfgang Fink is a German-American theoretical physicist. He is currently an associate professor and the inaugural Maria & Edward Keonjian Endowed Chair of Microelectronics at the University of Arizona. Fink has joint appointments in the Departments of Electrical & Computer Engineering, Biomedical Engineering, Systems & Industrial Engineering, Aerospace & Mechanical Engineering, and Ophthalmology & Vision Science at the University of Arizona. He is the current Vice President of the Prognostics and Health Management (PHM) Society.
Research career & education
Fink has a B.S. (Vordiplom, 1990) and M.S. (Diplom 1993) degrees in physics and physical chemistry from the University of Göttingen, Germany, and a Ph.D. "summa cum laude" in theoretical physics from the University of Tübingen, Germany (1997). He was a senior researcher at NASA's Jet Propulsion Laboratory (2001–2009). He was also a visiting associate in physics at the California Institute of Technology (2001–2016), where he founded Caltech's Visual and Autonomous Exploration Systems Research Laboratory. He also held concurrent appointments as Voluntary Research Associate Professor of both Ophthalmology and Neurological Surgery at the University of Southern California (2005–2014).
Active research areas
Fink is a specialist in the areas of autonomous systems, biomedical engineering for healthcare, human/brain-machine interfaces, and smart service systems. In particular, his research focuses on autonomous robotic systems for hazardous environments, C4ISR architectures (Tier-Scalable Reconnaissance), vision prostheses for the blind, smart mobile and tele-ophthalmic platforms, ophthalmic instruments and tests, self-adapting wearable sensors, cognitive/reasoning systems, and computer-optimized design.
Fink was a principal investigator of the United States Department of Energy's (USDOE's) "Artificial Retina" project (2004–2011), a multi-institutional and multi-disciplinary CRADA-based effort to develop an implantable microelectronic retinal device that restores useful vision to people blinded by retinal diseases (Retinitis pigmentosa and Macular degeneration). Furthermore, Fink is Caltech's founding Co-Investigator of the NSF-funded Center for Biomimetic Microelectronic Systems (2003–2010), awarded in 2003 to University of Southern California, Caltech, and UC Santa Cruz. The center enacted the only FDA-approved visual prosthesis to date (Argus retinal prosthesis or ARGUS II).
Honors & awards
Fellow of the National Academy of Inventors (NAI), Class of 2023 for having "demonstrated a highly prolific spirit of innovation in creating or facilitating outstanding inventions that have made a tangible impact on the quality of life, economic development, and welfare of society".
Recipient of the 2023 SPIE Aden and Marjorie Meinel Technology Achievement Award "for pioneering, sustained contributions to the development of transformational opto-medical examination and device technologies, with particular focus on visual prostheses for the blind, ophthalmology, and tele-ophthalmology."
Co-winner of USDOE/NREL-sponsored E-ROBOT Prize 2021 (Phase 1: $200,000), an American-Made Challenge, to devise building envelope retrofit solutions that make retrofits easier, faster, safer and more accessible for workers. The team "wall-EIFS" co-led by Fink devised "wall-EIFS: a robotically applied, 3D-sprayable exterior insulation and finish system (EIFS) for building envelope retrofits."
Recipient of the inaugural Scott Clements Most Valuable Person (MVP) Award of the Prognostics and Health Management (PHM) Society (2020).
ARVO Fellow, Class of 2023.
Fellow of SPIE (inducted in 2020) "for achievements in vision science for the blind and tele-ophthalmic healthcare worldwide".
Fellow of the Prognostics and Health Management (PHM) Society (inducted in 2018).
ACABI Fellow 2017 recognizing "faculty that are strongly active in innovation related to ACABI", the Arizona Center for Accelerated BioMedical Innovation at the University of Arizona.
da Vinci Fellow 2015 for "innovative, productive and highly recognized engineering research" at the University of Arizona.
Senior Member IEEE
College of Fellows of the American Institute for Medical and Biological Engineering (AIMBE) (inducted in 2012) "for outstanding contributions in the field of ophthalmology and vision sciences with particular focus on diagnostics and artificial vision systems".
Patents
Fink has been awarded 31 US and international patents to date in the areas of autonomous systems, biomedical devices, neural stimulation, MEMS fabrication, data fusion and analysis, and multi-dimensional optimization.
References
University of Arizona faculty
Living people
California Institute of Technology faculty
21st-century German physicists
Theoretical physicists
Year of birth missing (living people) | Wolfgang Fink | [
"Physics"
] | 1,029 | [
"Theoretical physics",
"Theoretical physicists"
] |
53,094,194 | https://en.wikipedia.org/wiki/NGC%205682 | NGC 5682 is a spiral galaxy located in Boötes. It had a supernovae called SN 2005ci. SN 2005CI is located at and (near the galaxy).
References
External links
Barred spiral galaxies
5682
09388
052107
Boötes | NGC 5682 | [
"Astronomy"
] | 59 | [
"Boötes",
"Constellations"
] |
53,094,397 | https://en.wikipedia.org/wiki/NGC%20410 | NGC 410 is an elliptical galaxy located in the constellation Pisces. It was discovered on September 12, 1784 by William Herschel. It was described by Dreyer as "pretty bright, pretty large, northeastern of 2.", the other being NGC 407.
One supernova has been observed in NGC 410: SN 1995Y (type I, mag. 18) was discovered by Jean Mueller on 28 August 1995.
References
External links
0410
17840912
Pisces (constellation)
Elliptical galaxies
004224 | NGC 410 | [
"Astronomy"
] | 107 | [
"Pisces (constellation)",
"Constellations"
] |
53,094,920 | https://en.wikipedia.org/wiki/3%2C9-Diethylidene-2%2C4%2C8%2C10-tetraoxaspiro%285.5%29undecane | 3,9-Diethylidene-2,4,8,10-tetraoxaspiro[5.5]undecane (DETOSU) is a bicyclic ketene acetal derived from the isomeric allyl acetal 3,9-divinyl-2,4,8,10-tetraoxaspiro[5.5]undecane (DVTOSU). As a bifunctional monomer, DETOSU is an important building block for polyorthoesters formed by the addition of diols to the activated double bond of the diketene acetal.
Preparation
DETOSU is prepared in a rearrangement reaction of DVTOSU, it is an exothermic reaction that also occurs spontaneously with complete conversion. For production on an industrial scale, the rearranged is carried out at elevated temperatures in the presence of catalysts.
The rearrangement reaction can be carried out in alkaline medium (such as with n-butyllithium in ethylenediamine or potassium tert-butoxide in ethylenediamine) but also photochemically by UV irradiation in the presence of iron pentacarbonyl as catalyst and triethylamine in boiling pentane or with dichlorotris(triphenylphosphine)ruthenium(II) / sodium carbonate in bulk.
In order to obtain purities sufficient for the use as a monomer, the crude product (obtained after the rearrangement reaction and vacuum distillation) must be recrystallized several times from pentane. The yields of pure product are about 50%.
Properties
3,9-Diethylidene-2,4,8,10-tetraoxaspiro[5.5]undecane is, when pure, a crystalline material at room temperature. Because of its low crystallization tendency, it is mostly used as a liquid. DETOSU is relatively unstable. It hydrolyzes rapidly even in the presence of only water traces and spontaneously isomerizes during storage to the diallylacetal DVTOSU, which is inactive for the polymerization. The pure substance is very reactive against the attack of electrophilic agents and ows a strong tendency for cationic polymerization. A characteristic property of DETOSU is the intense IR band at 1700 cm−1, which is also used to monitor the conversion in the rearrangement reaction.
Use
The diketene acetal 3,9-diethylidene-2,4,8,10-tetraoxaspiro[5.5]undecane, DETOSU, is a reactive bifunctional monomer that forms biodegradable polyorthoesters by polyaddition with α,ω-diols.
Polyorthoesters are used as embedding media for pharmaceuticals in extended release formulations for controlled drug release by surface erosion under physiological conditions.
References
Alkene derivatives
Spiro compounds
Dioxanes | 3,9-Diethylidene-2,4,8,10-tetraoxaspiro(5.5)undecane | [
"Chemistry"
] | 636 | [
"Organic compounds",
"Spiro compounds"
] |
53,095,406 | https://en.wikipedia.org/wiki/ECSS-E-TM-10-25A | ECSS-E-TM-10-25 "System Engineering - Engineering Design Model Data Exchange (CDF)" is a Technical Memorandum under the E-10 "System engineering" branch in the ECSS series of standards, handbooks and technical memoranda.
Scope and Purpose
This Technical Memorandum facilitates and promotes common data definitions and exchange among partner Agencies, European space industry and institutes, which are interested to collaborate on concurrent design, sharing analysis and design outputs and related reviews. This comprises a system decomposition up to any level and related standard lists of parameters and disciplines. Further it provides the starting point of the space system life cycle defining the parameter sets required to cover all project phases, although the present Technical Memorandum only addresses Phases 0 and A. This Technical Memorandum is intended to evolve into an ECSS Standard in the future. In conjunction with related development and validation activities, this Technical Memorandum should be regarded as a mechanism for reaching consensus prior to building the standard itself.
The Technical Memorandum provides the basis for creating interoperable Concurrent Design (CD) centers across the European space community. Allowing semantically consistent data exchange between CD centers. Enabling and supporting joint real-time collaborative design activities involving multiple CD centers. The initial objective of the TM is thus to act as a reference for the creation of new CD centers or upgrade of existing ones.
Structure
ECSS-E-TM-10-25A comprises the following parts:
Clause 1: Scope
Clause 2: Normative references
Clause 3: Terms, definitions and abbreviated terms
Clause 4: Background and concepts
Includes the description of the Space Engineering Information Model (SEIM), a conceptual data model for all information needed to conduct concurrent design sessions
Includes the description of the Space Engineering Reference Data Library (SERDL), an agreed collection of concurrent design organization roles, process concepts, disciplines and parameter types. These are predefined instances of SEIM concepts.
Clause 5: A list of requirements that two or more parties that want to exchange data for a concurrent design activity shall comply with.
Annex A: The formal definition of the Space Engineering Information Model (SEIM).
Annex B: The formal definition of the Space Engineering Reference Data Library (SERDL).
Annex C: The formal definition of the Web Services Interface and exchange file format.
Annex D: An informative description of margins and reference frames.
Software Implementations
Multiple software implementations of ECSS-E-TM-10-25A exist. These software implementations allow a team of engineers to collaborate on the design of a complex system such as a satellite, launcher, an oil rig or a building.
Open Concurrent Design Server (OCDS)
The Open Concurrent Design Server is a software package developed under a European Space Agency contract. It was the first attempt of an ECSS-E-TM-10-25A implementation. The software was never used in production and its further development was cancelled. The Open Concurrent Design Tool (OCDT) is the successor of the OCDS
Open Concurrent Design Tool (OCDT)
OCDT is a client / server software package developed under a European Space Agency contract to enable efficient multi-disciplinary concurrent engineering of space systems in the early life cycle phases. The OCDT client is an add-in for Microsoft Excel® 2010/2013, that is integrated with Excel® to perform simple analysis and simulation. Other client tools for engineering analysis and simulation can also be integrated, through the use of OCDT adapters. The OCDT server consists of a front-end web-services processor (using a REST API) and a back-end PostgreSQL database system for the persistent storage of OCDT shareable data. The server is able to support concurrent teams of more than 20 users and synchronising their engineering model content twice a minute or faster. Typically each user would represent a different domain of expertise (discipline). The package is distributed under an ESA community open source software licence available for use and further development to users that qualify as a member of the OCDT Community. OCDT is no longer being maintained.
The OCDT implements both Annex A (the formal UML model) and Annex C (the Webservices API).
RHEA Group Concurrent Design Platform (CDP4-COMET)
The Concurrent Design Platform (CDP4-COMET) of the RHEA Group is the main engineering tool to support multidisciplinary teams to perform Concurrent Design of complex systems. The CDP4-COMET, an evolution of the CDP3, is an ECSS-E-TM-10-25 Annex A and Annex C compliant implementation, as such it is 100% compatible with the ESA OCDT. CDP4-COMET is a client / server software solution implemented using C# and a Postgresql RDBMS. The CDP4-COMET Webservices (the server component) can be hosted both on Linux using Mono and Microsoft Windows®. The CDP4-COMET-IME is the desktop application that is compatible with Microsoft Windows® 7/10. A Microsoft Excel® 2010/2013 Add-in integrates many of the functionalities of the CDP4-COMET in Microsoft Excel® and is accessible through a dedicated Ribbon and Custom Task Panes. The CDP4-COMET implements both Annex A (the formal UML model) and Annex C (the Webservices API and exchange file format). The ESA CDF is using CDP4-COMET.
CDP4-COMET Community Edition is available as open source, the source code of the different components is available on GitHub:
The CDP4-SDK can be downloaded from Nuget. The CDP4-WebServices can be installed on any Linux flavor that supports Mono or using Docker.
References
External links
ECSS
ECSS-E-TM-10-25
ESA
ESA CDF
RHEA Group
Annex-C integration test suite
Mono Project
Concurrent Design Linked-In Group
European Space Agency
Space technology | ECSS-E-TM-10-25A | [
"Astronomy"
] | 1,214 | [
"Space technology",
"Outer space"
] |
53,095,612 | https://en.wikipedia.org/wiki/Ozark%20Iron%20Furnace%20Stack | Ozark Iron Furnace Stack, also known as the Ozark Iron Works, is a historic iron furnace located near Newburg, Phelps County, Missouri. It was built in 1873, and is a pyramidal shaped furnace stack constructed of hard, compact, fine-drained sandstone blocks on a solid rock foundation. It measures approximately 40 feet in height. The furnace was in operation until 1884. The furnace is located mostly on private property and may not be visible from public right-of-way.
It was listed on the National Register of Historic Places in 1970.
References
Ironworks and steel mills in the United States
Industrial buildings and structures on the National Register of Historic Places in Missouri
Industrial buildings completed in 1873
Buildings and structures in Phelps County, Missouri
National Register of Historic Places in Phelps County, Missouri
Industrial furnaces
1873 establishments in Missouri | Ozark Iron Furnace Stack | [
"Chemistry"
] | 166 | [
"Metallurgical processes",
"Industrial furnaces"
] |
53,095,923 | https://en.wikipedia.org/wiki/Smart%20cosubstrate | A smart cosubstrate is a type of cosubstrate used for cofactor regeneration to yield greater productivity and lower environmental impact (E-factor). A good example of a smart cosubstrate is a lactonizable diol.
In redox biocatalysis, the nicotinamide cofactor (NAD(P)H or NAD(P)+) can act as an electron donor or acceptor by releasing or accepting a hydride. The cofactor must be used in the reaction either in stoichiometric amounts leading to inhibition and economic issues, or in catalytic amounts coupled with an in situ regeneration system. A common approach catalytic amounts is excess use of sacrificial organic molecules such as isopropanol or ethanol. This approach, however, leads to stoichiometric amounts of waste.
The use of 1,4-butanediol as a smart cosubstrate for cofactor regeneration was the next step towards more sustainable redox biocatalysis (Scheme 1). The formation of a thermodynamically stable gamma-butyrolactone as a co-product drives the reaction to completion while yielding higher reaction rates. The use of 1,4-butanediol as an intelligent cosubstrate has also been validated in non-aqueous media using a commercial ADH.
Double-smart cosubstrate
Biocatalytic cascade reactions currently fall into four different categories:
Linear, which is biocatalytic
Orthogonal
Parallel
Cyclic
However, only two types of redox-neutral cascades have been reported for the in situ regeneration of the cofactors: parallel cascades (i.e., bi-substrate — no intermediate — bi- or tri-product) and linear cascades (i.e., single substrate — single intermediate — single product).
The concept of a smart cosubstrate was developed further through the design of a new class of redox-neutral "convergent cascade" reactions. Convergent cascade reactions involve a bi-substrate and a single product without the formation of an intermediate and were developed for the production of epsilon-caprolactone, which consists of a Baeyer-Villiger monooxygenase; for the oxidation of cyclohexanone; an alcohol dehydrogenase for oxidation of the "double-smart cosubstrate" 1,6-hexanediol; and for simultaneous regeneration of the nicotinamide cofactor. In 2016, two-step optimization of the convergent cascade by Design-of-Experiments and a biphasic system was reported.
Smart cosubstrates are an elegant solution for thermodynamically limited redox reactions and have many advantages:
Less conventional cosubstrates (e.g., isopropanol, ethanol) that negatively affect the enzymes’ activities need to be used.
Less waste is generated.
Reactions are faster, which could be caused by the absence of acetone or acetaldehyde as a coproduct, which lead to reduced enzyme activities.
References
Chemical processes | Smart cosubstrate | [
"Chemistry"
] | 652 | [
"Chemical process engineering",
"Chemical processes",
"nan"
] |
53,096,098 | https://en.wikipedia.org/wiki/Berkad | A berkad is a water reservoir used in arid areas to collect water during the wet season for use in the dry season. They occur mainly in Somalia and parts of Ethiopia.
Construction and operation
Berkads were introduced to Somalia in the late 1950s. Most are large rectangular, elongated basins with vertical walls and a capacity of several hundred cubic metres (similar to the size of a swimming pool), sometimes three to four metres deep. The walls and bottom are often covered in brick and/or coated with cement to reduce water loss due to infiltration to groundwater. At the top, they are open but often covered with canvas to reduce evaporation, or (in poorer villages) with nets on which is laid anything that provides shade (branches, straw, etc.).
Berkads fill naturally in the rainy season. They are placed in locations where small streams form during rain, which are then routed to the berkad with dug trenches. A berkad can sometimes be filled in a few hours. In villages with poor water availability, feed channels can be a few kilometres long, and take the form proper canals coated with cement and/or covered. Berkads are often clustered together.
Water quality
The inlet of the berkad often has a so-called "catch-pool": a small open reservoir that the water flows through before it enters the large basin. This allows a large part of the transported sediment to settle and other contaminants to be removed. The water in a berkad is nevertheless often turbid and muddy and can pose a health risk. One solution consists of making the tank airtight by constructing a sloping roof over the berkad, often with corrugated sheeting. Water evaporates, condenses on the underside of the roof, runs down into gutters and is collected in a separate metal tank, from which water can be used via handpump. This not only distills the water, but also reduces water losses due to evaporation. Such systems are, however, often too costly for villages to install themselves.
Flow-on-impacts
The construction of berkads also has disadvantages. In the late 1950s there were only still only a few water points in the Haud, a vast steppe on the border of Somalia and Ethiopia of importance to nomads with their cattle. Nomads roamed according to a traditional seasonal migration and always had to take into account the number of days to walk to the next place where they could water their cattle. Around 2001 there were already around 7000 berkads in the Haud, such that the area is now permanently grazed. This overgrazing leads to ecological degradation and erosion. Settlements also arise around clusters of berkads, increasing population pressure.
References
Environment of Somalia
Hydraulic engineering | Berkad | [
"Physics",
"Engineering",
"Environmental_science"
] | 570 | [
"Hydrology",
"Physical systems",
"Hydraulics",
"Civil engineering",
"Hydraulic engineering"
] |
53,097,045 | https://en.wikipedia.org/wiki/Karl-Georg%20Niebergall | Karl-Georg Niebergall (born 1961) is a German logician and philosopher and professor for logic and philosophy of language at Humboldt University of Berlin.
Biography
From 1982 Niebergall studied mathematics in Darmstadt. After that he studied logic and philosophy of science under Godehard Link and Matthias Varga von Kibéd at Ludwig Maximilian University of Munich (LMU). Niebergall received his PhD in philosophy from LMU in 1995. His PhD dissertation on ‘The metamathematics of non-axiomatized theories’ was awarded with the Stegmüller award of the German Society for Analytic Philosophy. In 1997 Niebergall was a visiting scholar at Stanford University. From 1998 he was associate professor at the department of philosophy at LMU. In 2002 Niebergall received his Habilitation with a dissertation on ‘The foundations of mathematics. Reducibility and ontology’. Since 2008, Niebergall has been professor for logic and philosophy of language at Humboldt University of Berlin.
Research
Niebergall’s research has centered on the metamathematics of formal theories related to mereology and infinity. He has also critically engaged with the works of Nelson Goodman, David Hilbert and William W. Tait.
Awards
A Stegmüller award of the German Society for Analytic Philosophy (1997) for his doctoral dissertation
References
External links
Works by Karl-Georg Niebergall (PhilPapers)
1961 births
20th-century German philosophers
21st-century German philosophers
German logicians
German philosophers of language
Mathematical logicians
Ludwig Maximilian University of Munich alumni
Academic staff of the Humboldt University of Berlin
Living people | Karl-Georg Niebergall | [
"Mathematics"
] | 324 | [
"Mathematical logic",
"Mathematical logicians"
] |
53,097,696 | https://en.wikipedia.org/wiki/Mu%20Octantis | The Bayer designation μ Octantis (mu Octantis) is shared by two stars in the constellation Octans:
μ1 Octantis, HR 7863 or HD 196051
μ2 Octantis, HR 7864 or HD 196067
Octantis, Mu
Octans | Mu Octantis | [
"Astronomy"
] | 61 | [
"Octans",
"Constellations"
] |
70,140,862 | https://en.wikipedia.org/wiki/Lanthanum%20cuprate | Lanthanum cuprate usually refers to the inorganic compound with the formula CuLa2O4. The name implies that the compound consists of a cuprate (CuOn]2n-) salt of lanthanum (La3+). In fact it is a highly covalent solid. It is prepared by high temperature reaction of lanthanum oxide and copper(II) oxide follow by annealing under oxygen.
The material adopts a tetragonal structure related to potassium tetrafluoronickelate (K2NiF4), which is orthorhombic. Replacement of some lanthanum by barium gives the quaternary phase CuLa1.85Ba0.15O4, called lanthanum barium copper oxide. That doped material displays superconductivity at , which at the time of its discovery was a high temperature. This discovery initiated research on cuprate superconductors and was the basis of a Nobel Prize in Physics to Georg Bednorz and K. Alex Müller.
References
Inorganic compounds
Copper compounds
Lanthanum compounds
Oxides | Lanthanum cuprate | [
"Chemistry"
] | 225 | [
"Inorganic compounds",
"Oxides",
"Salts"
] |
70,141,217 | https://en.wikipedia.org/wiki/Punctularia%20strigosozonata | Punctularia strigosozonata is a fungus species of the genus Punctularia. It was originally described in 1832 by Lewis David de Schweinitz as a member of genus Merulius. Patrick Talbot transferred it to genus Punctularia in 1958. Punctularia strigosozonata produces the antibiotic phlebiarubrone.
References
Punctulariaceae
Fungi described in 1832
Taxa named by Lewis David de Schweinitz
Fungus species | Punctularia strigosozonata | [
"Biology"
] | 102 | [
"Fungi",
"Fungus species"
] |
70,142,375 | https://en.wikipedia.org/wiki/Polysulfobetaine | Polysulfobetaines are zwitterionic polymers that contain a positively charged quaternary ammonium and a negatively charged sulfonate group within one constitutional repeat unit. In recent years, polysulfobetaines have received increasing attention owing to their good biotolerance and ultralow-fouling behavior towards surfaces. These properties are mainly referred to a tightly bound hydration layer around each zwitterionic group, which effectively suppresses protein adsorption and thus, improves anti-fouling behavior. Therefore, polysulfobetaines have been typically employed as ultrafiltration membranes, blood-contacting devices, and drug delivery materials.
The chemical structure of polysulfobetaines can be divided in several subgroups. Most widespread are amides of (meth)acrylic acid ('PSPP') or quaternary esters ('PSPE'). Also, compounds from poly(vinylpyridinium), poly(vinylimidazolium), or quaternary poly(pyrrolidinium) as well as zwitterionic ionenes, are often found.
Synthesis
Polysulfobetaines are generally synthesized via free radical polymerization. However, the synthesis of polysulfobetaines is often limited by their poor solubility in most solvents and at present, only few sulfobetaine monomers that are suited for free radical polymerization, are commercially available. The most popular ones are SPE and SPP, which provide a good combination of hydrophilicity and polymerizability.
Solution behavior
Almost all polysulfobetaines are insoluble in water at low temperatures, however many polysulfobetaines feature an upper critical solution temperature (UCST) in aqueous solution. This means they undergo a coil-to-globule collapse transition upon cooling. Such a behavior is highly unusual, since other zwitterionic polymers, e.g., poly(phosphatidylcholines) and poly(carboxybetaines) do generally not feature a responsive behavior towards a temperature stimulus.
The reason for the UCST-type behavior of polysulfobetaines in solution is based on their electrically neutral behavior, i.e., the overall charge is zero, over a large pH range (approximately 2 – 14). Due to the neutralization of the charges, repulsive and attractive interactions are present between the individual polymer chains and inner salt are formed. The balance of this complex interplay of interactions between numerous charged groups with water and with themselves, strongly affects the solubility of polysulfobetaines in water and eventually, results in an UCST-type transition. The temperature of this phase transition, often called clearing point, is very sensitive to molar mass, polymer architecture, solvent isotopes, e.g., H2O/D2O, and especially to the addition of salts to the solution.
The presence of salt additives in aqueous solution leads to an altered balance of the attractive and repulsive interactions and therefore, also to an altered solubility. Especially, the nature of the salt anion has a strong effect on the solubility of the polysulfobetaines. While chaotropic anions cause an improved dissolution (salting-in effect), kosmotropic anions result in precipitation of the polysulfobetaines (salting-out effect).
Thin films from polysulfobetaines
Thin films made from polysulfobetaines also feature a thermo-responsiveness, however, the phase transition is strongly shifted, which is mainly addressed to the increased polymer concentration and the altered polymer-polymer and polymer-water interactions. Furthermore, and analogously to aqueous solutions, different water isotopes (H2O/D2O) and salt additives were found to affect the phase transition as well. Interestingly, polysulfobetaine thin films feature a cononsolvency effect in mixed water/methanol vapors, which is not found in water/methanol solution. Apparently, polysulfobetaines feature a miscibility with lower alcohols at the substance-rich side of their phase diagrams.
References
Zwitterions
Quaternary ammonium compounds
Sulfonates
Polymers | Polysulfobetaine | [
"Physics",
"Chemistry",
"Materials_science"
] | 902 | [
"Matter",
"Zwitterions",
"Polymer chemistry",
"Polymers",
"Ions"
] |
70,142,435 | https://en.wikipedia.org/wiki/Sunduki | The mountain range Sunduki is a natural and historical monument of local significance in the Ordzhonikidzevsky and Shirinsky districts of the Republic of Khakassia, Russia. Since June 18, 2011, the Sunduki museum has been operating on the territory of the mountain range.
Etymology
; .
; Khakas: Онло Tағ, romanized: Onlo Takh (Onlo Tag), lit. 'Onlo Mountain'
Description
The mountain range has a total area of 2100 hectares, stretching from south to north. It is the foothills continuation of the Efremkinsky ridge of the spurs of the Kuznetsk Alatau in the valley of the Bely Iyus river. The ridge consists of five separate mountain-remnants or buttes up to 200 meters high. The ridge got its name from the northernmost mountain, on top of which there is a rock in the form of a parallelepiped, which resembles a chest. The mountains themselves received the corresponding serial numbers: 1st, 2nd, 3rd, 4th and 5th Sunduki. The butte is composed of red Devonian sandstone of a characteristic red-brown color, hence its Khakas name Khyzyl-khaya (Red-Rock). The Sunduki mountains are characterized by a sharp asymmetry: the eastern slope at the top is very steep, while the western slope gently descends into the valley.
Sometimes four more mountains are attributed to the Sunduki, south of the channel of the Bely Iyus river: Abyyakh-khaya (Brotherly rock), Krest-khaya (Cross rock), Orta-khaya (Middle rock), Uzun-khaya (Long rock). These are the 6th to 9th Sundiki, respectively. All mountains in the range are quite low and accessible for climbing. From the top of the Sunduki you can see the surrounding low mountain ranges, neighboring Sunduki and open view of the ancient irrigation canals (1st millennium BC) in the Bely Iyus river valley.
Nature
The Sundiki are a protected area of the Russian Federation. The status of protected areas was determined by the decision of the Khakass regional executive committee dated July 21, 1988 No. 164. Under protection are: various variants of phytocenoses, preserved virgin areas of the steppes, habitats of valuable, rare and endemic plants (Bupleúrum scorzonerifólium (lat.), Panzerina lanata (L.), Large-flowered slipper, Dryas, etc.) and the habitat of rare bird species (Peregrine falcon, Saker falcon, Lesser kestrel, Eastern imperial eagle, Horned owl, Steppe eagle).
History
Historical sites associated with ancient human settlements, petroglyphs or pisanitsas of Tagar culture, tamga-petroglyphs, cultural and historical complexes, burial mounds, ancient burials, etc.
The fortress (khak.) Sve on mountain Tағ Onlo (1st Sunduk) is a small fortified area on several rocky ridges separated by deep logs. The stone wall runs along the western edge of the foot of mountain Onlo. Encircling the mountain, it rises up the slope to the rocky terraces, blocking the entrance to the mountain canyon in the most vulnerable place. The wall is a stone and earth rampart, best preserved in the central part. In the embankment flattened from above, turfed stones are visible everywhere, in some places there are vertical slabs on the outside. A fairly large fortification was probably used as a shelter for the population and livestock during hostilities. Sve on mountain Onlo is, apparently, part of the system of defensive structures in the valley of the Bely Iyus river. (khak.) Sve Onlo fortress is located on the western bank of the river. On the east coast, 10 kilometers north of Onlo, there is the (khak.) Sve Tarpig fortress. Today, the ruins of such ancient structures bear little resemblance to fortress walls and can be confused with the natural collapse of stones. Due to the poor study and the almost complete absence of dating finds, until recently, many scientists considered such structures to be medieval Kyrgyz or Mongolian fortresses-shelters, in which people temporarily took refuge from attacks, even calling them "ancient Tatar mountain fortresses".According to legend, the fortification on mount Onlo was built by the Teleut prince Silig ool Chaizan. Probably built in the Bronze Age, the fortification functioned until the Middle Ages. It is also possible that during the period of the Kyrgyz state (VI-XIII centuries), the ancient wall was restored or even partially rebuilt, which was reflected in folk tales.
Interesting to notice that heroic epic tales of the Yakuts called Olonkho, which resembles similarity with name of Onlo (1st Sunduk).
There are many legends around the Sunduki. The mythical hero (khak). Khoho-Babay is said to have lived there, guarding the sacred valley from uninvited guests for thousands of years, and hiding its riches in a giant forged chest (1st Sunduk). He was rich and greedy, collecting treasure and turned it into a huge gold ingot so as not to share it with anyone. However, he did not know that admiring gold for a long time alone leads to complete blindness. Blinded, the hero turned to the gods with a plea to restore his sight. They demanded a precious ingot in return. Khoho-Babay cheated and promised to give them anything for the returned vision, but he deceived the gods. For this, the gods turned him into a bird of prey, and his wealth into a stone chest on top of the mountain. Since then, the deceiver has been circling over the mountain range in the hope of gaining a human form.
On the 1st Sunduk on mount Onlo there is a rock called "Seated King" or "Shaman chair". It is unique in its acoustics, because even word spoken in a whisper, will be heard several hundred meters away. On 1st Sunduk there were also carved faces, the so-called face of a warrior and the face of a shaman.
Interesting to notice description of the typical performances example of Yakut Shaman in action:
There are known 12 carved stones in shape of chests with name Onlo in Khakassia and 8 of them are located on the tops of the mountains. 5 Onlo chests are made of white stone (quartz or marble) and stand in areas where there is no outlet for these rocks nearby. Local people traditionally attributed Onlo stones to the legendary Chud people.
On 4th Sunduk there are group of petroglyphs or (rus) Pisanitsa carved more than two thousand years ago. These petroglyphs are a kind of the Tagar heroic epic, they show not only the difficult earthly path of the hero, but also the other world where he ends up after being killed by an enemy lurking in ambush, depicted in the lower part of the stone slab.
On the 5th southernmost Sunduk there is the "Temple of Time", which is a kind of measuring device. It represents a carved niche in which there is a sundial in the form of a Dragon, cut into six parts. It is not yet known how the ancient people were using it. Some believe that the Temple of Time is the oldest astronomical observatory. At the foot of the 5th Sunduk, there is a large group of burial grounds.However, after the work of archaeologists, it became clear that many Sve, including Sve Onlo, were built not a thousand, but about 4 thousand years ago. Basically, they appeared in the Okunev era (mid- 2nd millennium BC). According to Gottlieb A., head of the KSU archaeological laboratory, which carried out a large-scale study of similar mountain structures in 1988, including Sve Onlo, "archaeological excavations convincingly confirm the existence of Sve even in the Early Bronze Age. Ceramics of this time are important evidence".
Larichev V.E. greatly contributed to the study and popularization of the Sunduki range. He was the author of numerous scientific and popular science books, in particular on archaeoastronomy: interpretations of cultural monuments of ancient people. According to the researcher, Sve Onlo (1st Sunduk, Saratsky Sunduk) was a sacred place from which we can learn about its creators' idea of the structure of the universe. He claims it represents an astrological sanctuary, including a priestly temple and an ancient observatory.
See also
Ancient North Eurasian
Proto-Yeniseian
Yeniseian people
Prehistory of Siberia
Afanasievo culture
Andronovo culture
Okunev culture
Mal'ta–Buret' culture
Tagar culture
Yenisei Kyrgyz
Yenisei Kyrgyz Khaganate
Dingling
Olonkho
Tomskaya Pisanitsa Museum
Afontova Gora
Oglakhty
Chebaki Fortress Sve-Takh
History of skiing#Early archaeological evidence
Böksta Runestone
References
Sources
Printed sources
State report "On the state of the natural environment of the Republic of Khakassia in 1998" (The same, 1999, 2000, 2001).
Encyclopedia of the Republic of Khakassia: [in 2 volumes] / Government of the Rep. Khakassia; [scientific-ed. Council.: V. A. Kuzmin (prev.) and others]. - Abakan: Polikor, 2007. Vol. 1: [A - H]. - 2007. - 430, [2] p. : ill., portr. — Bibliographer. at the end of words. Art. S. 150.
Web-sources
Samoilova G.S., et al. KHAKASIA // Great Russian Encyclopedia. Electronic version (2020) Retrieved: 25.02.2022
Kuzminykh S. V. TAGAR CULTURE // Great Russian Encyclopedia. Electronic version (2017) Retrieved: 25.02.2022
Mountain ranges of Russia
Rock formations of Russia
Mountains under 1000 metres
Natural history of Siberia
Protected areas of Siberia
Landforms of Khakassia
Upper Paleolithic sites
Archaeological sites in Siberia
Archaeological cultures of Siberia
Scytho-Siberian world
Prehistoric sites in Russia
Archaeoastronomy
Yeniseian languages
Rock art in Asia
Open-air museums in Russia | Sunduki | [
"Astronomy"
] | 2,177 | [
"Archaeoastronomy",
"Astronomical sub-disciplines"
] |
70,143,069 | https://en.wikipedia.org/wiki/The%20Adventures%20of%20Massang | The Adventures of Massang is a Kalmyk folktale about a strong hero born of a cow, who finds three companions and has further adventures. The tale was published in the Siddi-Kur (or Siddhi-Kur), a compilation of Kalmyk and Mongolian stories.
The story is related, in the international Aarne-Thompson-Uther Index, to type ATU 301, "The Three Stolen Princesses", as a former subtype, AaTh 301B, "The Strong Man and his Companions": a hero of hybrid human-animal origin finds strong companions and climbs down to an underworld, and is eventually betrayed by his companions.
Origin
The Tales of the Bewitched Corpse is a compilation of Indo-Tibetan stories that was later brought to Mongolia and translated to Mongolic languages. The collection is known in India as Vetala Pañcaviṃśati, in Tibet as Ro-sgrung, in Mongolia as Siditü kegür, and in Oirat as Siddhi kǖr.
In this regard, Mongolian linguist Tsendiin Damdinsüren noted the existence of two Tibetan compilations of Vetala tales, one with 13 chapters and the other with 21. Also, both versions were mentioned in the work The Book of the Son, written in the 11th century. Lastly, the divergence in contents between the Indian Vetala and the Tibetan versions, according to Damdinsuren, may indicate the latter were original works, instead of an adaptation or translation. In the same vein, according to Tibetologist Françoise Robin, there are more than 20 versions of the compilation in the Tibetan-speaking zone alone, and their common versions contain between thirteen and twenty-five stories, with some even reaching up to 75 tales.
Hungarian Mongolist Lászlo L. Lörincz (1965) noted that the tale of Massang contained two "independent" parts connected as a loose whole. In the same vein, Tibetologist Rolf Stein argued the tale of Masang existed as "an indigenous tale" before being inserted into the compilation as the third story of the Tibetan and Mongolian redactions of The Bewitched Corpse, being also mentioned in other works, such as Father's Teaching and the Son's Teaching (Pha-chhos, Bu-chhos), from the 11th century.
Summary
Slaying the Shimmu
In the tale How the Schimnu-Khan was Slain, of Tibetan or Mongolian provenance, the first part shows the birth of a youth named Massang "of the bull's head". A poor man's only cow gives birth to a half-man, half-cow hybrid and its owner is horrified by the creature. The cow-man, receiving clemency, flees from the old man and into the world. The youth meets a "black-coloured man (...) born of the dark woods", a "green-coloured man (...) born of the green meadows" and a "white-coloured man (...) born of the crystal rock" and the quartet soon move to a dwelling overlooking a hill. They take turns cooking the food while the others gather game nearby. One day, a small old woman appears and beats the three companions to steal their food ("milk and meat", as the story says). On the fourth day, Massang sees the little old woman and matches strength with the creature. After three tests, the little woman escapes and leaves behind a blood trail for the four heroes to follow. They soon come to an opening in the rock; down below, the witch's corpse strewn about near heaps and heaps of treasure. Massang descends to take the treasure to his companions but they betray him and leave him for dead in the pit. Massang sleeps on the witch's corpse - for years - and when he awakes, three cherry trees have sprouted, which he uses to climb to the surface. He visits his treacherous companions and discovers they have made a life for themselves with the witch's treasure, but they beg Massang to spare them.
Origin of a constellation
In the second part of the tale, Massang decides to spare his former companions and carries on with his life. He finds a beautiful maiden carrying water in a jug and follows her. Massang arrives at the court of Churmusta Tengri, who bids welcome to the hero and tells him his arrival is most propitious. Churmusta Tengri explains that there will be a war between a white host of Tengri forces and the black host of the Schummu. Massang helps the white hosts by defeating the black host leader. At the end of the tale, a Schummu strikes a hammer against the ground and sparks fly out, originating seven stars of a constellation (Ursa Major or the Pleiades). In this version of the tale, translated by British folklorist Rachel Harriette Busk, the narrator, in the framing device of the book, comments that he never returned to his master to bring him riches.
Versions
translated the tale as Massang's Adventure. In his translation, Massang's companions are a "dark complexioned man (...) descended from the forest", a man of green colour "born of the turf" and a white man originated from crystal.
The tale was also translated by Charles John Tibbits as The Adventures of Massang, wherein Massang is described as horned; the dark man is called Iddar, Son of the Forest, and the other two Son of the Grass and Son of the Sedges. In his translation, the Schummu smites Massang and from this action seven stars spring out.
In a Russian language translation of the tale, titled "Массанг" ("Massang"), published in 1978, the hero's companions are given the following names: Idder (Иддер) of the dark woods; Geger (Гегер) of the green fields/meadows; and Adder (Аддер) of the white mountains. This tale also contains the origins of the constellation, but ends on a happy note.
Massang also appears in a Tibetan and in a Kalmyk tale. In the latter, he is born from a human couple in the country of India, but still shows the bull/ox features, like horns and a tail.
In a version of the tale translated by author Eleanore Myers Jewett with the title The Promise of Massang, sourced as Tibetan, the translator removed the animal birth of the hero, thus making him a normal boy instead. The tale lacks the second part about the origin of the constellation, and ends with Massang bringing the cow's owner the riches he promised.
Variants
According to German Tibetologist Dieter Schuh, the tale of the ox-man and the origin of the constellation appears in both Tibetan and Mongolian literature. Hungarian orientalist László L. Lőrincz remarked that the tale is attested in a Tibetan collection named Ro-sgruṅ ("The Magic Corpse"), with the title Ya-ru-kha-khra'i le'u-ste. He also noted that the tale is popular in Mongolia, published in the Siditü kegür, and the hero may be known by the Tibetan name Yarupa or by Masang.
Mongolia
Hungarian orientalist László L. Lőrincz established the classification of the Mongolian tale corpus, published as Mongolische Märchentypus ("MMT"). In his system, he indexed a Mongolian type numbered MMT 127, Der kalbsköpfige Masang ("The Calf-Headed Masang"), which corresponds to tale type 301B. In the tale type, a hybrid son is born of a union between a man and a cow or a man and a she-bear; in his youth he meets equally powerful companions and they move out to a house; a diminute demoness attacks the heroes while they are preparing food, and Masang defeats her; they follow the trail to a hole and Masang descends and defeats the witch; he steals the demoness's treasure, but his companions abandon him down below; to escape, he plants a magical seed for a tree to grow or a bird carries him up to the surface. Later, Masang helps deity Qormusda in his battle against demons; Qormusda either transforms Masang to human form, or he dies and his body is sundered to make the Ursa Major constellation; or he intervenes in a war between two Khans and marries the daughter of the victor.
, Hungarian professor of Mongolian studies, provided a Hungarian language translation of a Mongolian tale with the title "Ам цагаан бяруу". In his translation, titled Am Cagán Bjarú, a Fehérszájú Borjú ("Am Cagán Bjarú, The White-Mouthed Calf"), the constellation Dolon Burhan ("The Seven Buddhas") was originally a man named White-Mouthed Calf. The story is largely the same: the ox-man hero is born of a cow, meets three companions (a man from the forest, a man from the woods, and a man sat on a stone), and finds them a house. While there, a mysterious old woman appears and demands a bit of their food, and attacks them after being denied. The White-Mouthed Calf hurts the old woman and follows her to a pit, he is betrayed by his companions, but reaches the surface after three years by climbing on three trees that sprouted on the old woman's corpse. At the end of the tale, the White-Mouthed Calf helps the Celestial Emperor against the Emperor of Demons, but an evil woman, ally of the Emperor of Demons, strikes the hero with a weapon and his body is torn apart in seven pieces. The Celestial Emperor takes the seven pieces and creates the Seven Buddhas constellation.
Buryat people
Folklorist translated and published a Buryat tale titled "Тугал Масан" ("Tugal Masan"). The tale is inserted as a story-within-a-story told by the Burkhan: Tugal Masan meets a Black Tarba, a White Tarba, and a Blue Tarba. In the part about the celestial king, Tugal Masan is recruited to fight against the black yak army of Khara Lusan Khan. At the end of the tale, Tugal Masan survives and is offered to marry the daughter of the celestial king, but he declines.
Tibet
Tibetologist David MacDonald translated and published a Tibetan tale he titled The Story of Yakro Kharto. In this tale, a widowed man goes hunting and finds the bull-man in the forest. The bull-man, named Yakro Kharto, begs to be spared and flees into the woods. He meets three companions: a black man named Forest-Born, a green youth named Born-in-the-Grass and another named Born-in-a-Glass-House. The tale is much the same: the companions' betrayal, the small old woman and the return to the surface by climbing the peach tree. In the second part of the story, Yakro Kharto follows the maiden and meets King Gyajin, who asks his help in defeat in the evil spirits. At the end of the tale, the gods descend a rope from the heavens which Yakro Kharto climbs up and reaches the stars.
In a variant titled Masang Yharu Khadra, sourced as from Tibet, the hero is born with a bull's head and tail and given the name Masang Yharu Khadra. He meets his companions (a man with face as black as wood bark, another with face as blue as the grasslands, and the third with face as pale as a rock). He is betrayed in the same manner and escapes the hole by climbing up three peach trees. When he meets the girl, he follows her and climbs up a rose vine to the sky, where he meets the leader of the gods of heaven, who enlists Masang's help. The next day, the forces of heaven assume the shape of white yaks and fight the demonic forces, who are in the shape of black yaks.
In a Russian language translation by Tibetologist , the hero's name is given as "Пегий бычок" (English: "Piebald Bull Calf"), and its source is explicitly named "Игра Веталы с человеком" ("Vetala's Game with a Man").
Analysis
Parallels
Folklorist William Ralston Shedden-Ralston called Massang the "Calmuck Minotaur", in reference to the hybrid bull-man creature of Greek myth. Charles Fillingham Coxwell also related Massang to the Greek Minotaur.
Coxwell saw a parallel between Massang and Lorraine (French) hero "John of the Bear" (Jean de l'Ours), another strong hero with animal parentage.
Hungarian scholarship argue for a parallel between the Kalmyk Massang and a similar figure of Hungarian folktales: Fehérlófia ('Son of the White Mare'), a youth born of a white mare.
Tale type
W. R. S. Ralston related the story to an international narrative wherein a hero, joined by two companions (his brothers or not), follows a creature to its underground lair; the hero is lowered by a rope and finds down there either kidnapped princesses or some treasure. Either way, the hero is abandoned by the other two in the underground to perish, but eventually escapes and punishes his traitorous companions. These tales were later classified in the international index Aarne-Thompson-Uther as tale type ATU 301, The Three Stolen Princesses (or The Three Underground Kingdoms, in Russian academia).
According to philologist researcher Irina S. Nadbitova, from the Kalmyk Institute for Humanities research RAS, a similar narrative exists in the Kalmyk Folktale Corpus, but the bull-man hero is disenchanted by a girl at the end of the tale. Nadbitova classified it as type 430, "Юноша-бык" ("The Bull Youth").
Other motifs
The little old woman who attacks the heroes is described as a Schimnu or Schumnu, which the translator considered to be a version of Mara, a demonic being in Buddhism.
Lörincz suggests that the coloured companions in the Tibetan tale may represent guardian spirits of the woods, the meadows and the mountains, or be interpreted as indications of the cardinal directions. Also, the heavenly deity or king, named Dbaṅ-po brgya-byin in the Tibetan text, is equivalent to Sanskrit Śatakratu, that is, Indra.
The birth of the constellation
The second part of the tale of "ox-man" Massang (or Masn Mirü) involves his fight against a powerful enemy king and the origin of a constellation. However, scholarship suggests that this second part is an addition to the original tale. Scholarship points out that the story of Massang serves as an etiological tale to the origin of a seven-star constellation known as "Долон Эбуген" ("Seven Elders") or "Долан Бурхн" ("Seven Deities"). According to Hungarian orientalist László L. Lőrincz, the tale is another myth to explain the origin of the Great Bear.
See also
Prâslea the Brave and the Golden Apples (Romanian fairy tale)
The Story of Bensurdatu (Italian fairy tale)
Dawn, Midnight and Twilight (Russian fairy tale)
The Gnome (German fairy tale)
The Norka (Russian fairy tale)
Jihaguk daejeok toechi seolhwa (Korean folktale)
The Son of a Horse (Chinese folktale)
References
Asian fairy tales
Mythological human hybrids
Asian folklore
Astronomical myths
Tibetan literature
Mongolian literature
ATU 300-399
Panchatantra | The Adventures of Massang | [
"Astronomy"
] | 3,347 | [
"Astronomical myths"
] |
70,144,487 | https://en.wikipedia.org/wiki/Mimesis%20%28biology%29 | In biology, mimesis (from ancient Greek μίμησις mímēsis, "imitation") is a form of crypsis where living creatures mimic the form, colour and posture of their surroundings to avoid being noticed from their surroundings by predators depending on sight. One view is that mimesis, being a form of crypsis, differs from mimicry, but in English, mimesis is often counted as one of several forms of mimicry.
Zoomimesis
Zoomimesis is mimicry of different animals. Examples include various visitor species of ants (myrmecophily), resembling the ants in whose nests they live.
Phytomimesis
Phytomimesis is mimicry of plants or parts of plants. Some geometer moths resemble thin twigs in appearance. Stick insects have a body shape resembling twigs or leaves (as in walking leaves). Notodontidae moths resemble the bark of deciduous trees. Some species in this family, such as the alder kitten and the sallow kitten moths, have cocoons resembling tree bark. Some potoo birds resemble broken branches.
Allomimesis
Allomimesis is mimicry of lifeless objects. Some small butterflies resemble bird droppings. Some species of fig-marigolds living in African deserts resemble stones and are thus known as "living stones".
Allomimesis developed already 50 million years ago in micromoths, whose quivers in their larval stage resembled the forest soil. Evidence of this has been preserved in Baltic amber.
See also
Adaptive Coloration in Animals
References
Mimicry
Animal communication | Mimesis (biology) | [
"Biology"
] | 324 | [
"Mimicry",
"Biological defense mechanisms"
] |
70,145,567 | https://en.wikipedia.org/wiki/Chevrolet%20Gemini%20small-block%20engine | The Chevrolet Gemini small-block engine is a dual-overhead cam (DOHC) V8 engine designed by General Motors. While technically a small-block engine because of its bore spacing of 4.4 inches, General Motors engineers do not consider it to be a part of the traditional Chevrolet small block lineage because of the substantial reworking, specialized development, and unique technical features distinguishing its design.
The Gemini is a clean-sheet design, mechanically unrelated to both the LS-based engines and the Cadillac Blackwing V8. Its most notable traits include a flat-plane crankshaft and dual-overhead camshafts, which represents a departure from the traditional pushrod valves and crossplane crankshafts found in all previous generations of Chevrolet small-block engines. As of July 2024, the Gemini engine has two variants, dubbed LT6 and LT7.
LT6
The LT6 is a 5.5-liter, naturally-aspirated V8 engine. It debuted in the eighth-generation Corvette Z06, and was unveiled on October 26, 2021.
While the LT6 features a redline of 8,600 RPM, it generates a maximum of at 8,400 RPM and of torque at 6,300 RPM. These figures make it the most powerful naturally-aspirated production V8 engine of all time; the engine to previously hold this title, the Mercedes-Benz SLS AMG Black Series M159 6.2-liter V8, made at 7,400 RPM.
The LT6 is also the largest flat-plane V8 used in a production car by displacement, dethroning the Ford Voodoo. This is notable due to the additional vibrations inherent to this architecture compared to a crossplane V8, which tend to scale up with displacement.
A modified version of the LT6 has powered the Chevrolet Corvette C8.R since 2019, and many features in the racing engine carry over to the road engine. Other notable features include a cast aluminum block, dual coil valve springs supporting titanium intake & sodium filled exhaust valves, forged aluminum pistons, forged titanium connecting rods, active split intake manifold with twin 87mm throttle bodies, four-into-two-into-one stainless steel exhaust headers, and a factory six-stage 10-quart dry sump oiling system with individual crank bay scavenging.
Applications:
LT7
The LT7 is a twin-turbocharged variant of the LT6 which debuted in the eighth-generation Corvette ZR1 and was unveiled on July 25, 2024. The LT7 has a redline of 8,000 RPM, generating at 7,000 RPM and of torque at 6,000 RPM.
Although it was released later, the LT7 was developed in tandem with its LT6 sibling. Compared to it, the LT7 has stronger pistons and connecting rods. Combined with the bigger combustion chamber on the heads, this lowers the compression ratio from 12.5:1 to 9.8:1. Unlike the LT6, the LT7 uses both direct fuel injection and port injection, with a total of 16 injectors. However, the block casting is identical, and the crankshaft is almost identical. The turbochargers produce up to in normal operating conditions and a maximum of under high temperatures. Other features specific to the LT7 include turbo-integrated exhaust manifolds, water-to-air intercoolers, and an electrically actuated wastegate.
Applications:
See also
Chevrolet small-block engine
General Motors LS-based small-block engine
List of GM engines
References
Chevrolet engines
General Motors engines
V8 engines
Gasoline engines by model
Engines by model | Chevrolet Gemini small-block engine | [
"Technology"
] | 730 | [
"Engines",
"Engines by model"
] |
70,146,242 | https://en.wikipedia.org/wiki/Rescue%20behaviour | Rescue behaviour is a form of altruistic behaviour shown by animals where an individual in distress is aided appropriately by another individual which puts itself at risk in the process. The term "rescue behaviour" was first introduced in the title and in the text of a paper by Wojciech Czechowski, Ewa Joanna Godzińska and Marek Kozłowski (2002) that reported the results of field observations and experiments documenting this behaviour in workers of three ant species, Formica sanguinea, Formica fusca and Formica cinerea that were observed to try to rescue individuals captured by antlion larvae (Myrmeleon formicarius). Criteria allowing to tell apart rescue behaviour from other forms of cooperation and altruism were subsequently provided by Elise Nowbahari and Karen L. Hollis.
Rescue behaviour has been demonstrated in a very limited range of animals that include ants, primates including humans, a few bird species, such as the Australian magpie, and wild boar.
References
Ethology | Rescue behaviour | [
"Biology"
] | 206 | [
"Behavioural sciences",
"Ethology",
"Behavior",
"Ethology stubs"
] |
70,147,600 | https://en.wikipedia.org/wiki/Stray%20cattle%20in%20India | India has over 5 million stray cattle according to the livestock census data released in January 2020. The stray cow attacks on humans and crops in both urban and rural areas is an issue for the residents.
Cow slaughter is banned in many places in India with penalties of long imprisonment and huge fines. Fear of arrest, persecution, and lynching by cow vigilantes has reduced the trading of cows. Once a cow stops giving milk, feeding and maintenance of the cow becomes a financial burden on the farmer who cannot afford their upkeep. Cattle that farmers are unable to sell are eventually abandoned. A cow is considered "stray" when its owner no longer claims ownership or its owner cannot be determined.
Stray cattle are a nuisance to traffic in urban areas and cause road accidents. The problem of solid waste pollution, especially plastic pollution and garbage dumped at public places, poses a risk to stray cattle which feed on garbage.
Causes
Slaughtering cows is illegal in most of India, because cows are considered holy in Hinduism. The anti-slaughter laws were not strictly enforced until 2014, when the Bharatiya Janata Party (BJP) came to power. Before this, farmers regularly took their old cows to slaughterhouses. Since 2014, cow slaughter has been made illegal in 18 states in India including Uttar Pradesh. In Uttar Pradesh, many slaughterhouses were closed down by the BJP state government, in accordance with the party's right wing Hindu agenda.
Growing mechanization in the farming industry has also put cattle out of use as working animals, and increased the number of cattle abandonment cases. Fear of arrest, persecution, and lynching by cow vigilantes has also reduced the trading of cattle. Once a cow stops giving milk, feeding and maintenance of the cow becomes a financial burden on the farmer who cannot afford their upkeep. Cattle that farmers are unable to sell are eventually abandoned to wander.
Impact
Stray cattle pose a number of threats to human residents and animal welfare in both urban and rural areas. Stray cattle have been known to feed on standing crops and attack humans.
Airports
Stray animals are common on the runways of Indian airports. These stray animals, including cattle, pose a major threat to air safety in most airports across the nation. According to Airports Authority of India (AAI) officials, animals straying onto a runway are routine at many airports in India.
In 2018, a stray cow on a runway caused chaos at Ahmedabad airport leading to two planes aborting their landings. The cow crept past security at a cargo gate at the Sardar Vallabhbhai Patel International Airport, in Ahmedabad, resulting in a cargo plane being diverted to Mumbai and delaying five domestic flights and several departures. It took over 90 minutes for the security personnel to clear the runway.
Railway
In 2019, Vinay Kumar, the Uttar Pradesh vice-president of the farmers union, Bharatiya Kisan Union, had said "Cows are roaming in the open because there is no buyer and the promised gaushalas [cow shelters] are not operational. They are also destroying crops. Farmers chase them out of their fields. Railway lines are near fields, and the cattle go to open areas near the railway lines; some, unfortunately, come under a train."
The lack of adequate number of cowsheds (gaushalas) and the strict slaughter and trading laws were reported by The Wire as the main reasons for increase in cows roaming around and causing more cow related incidents in comparison to earlier years.
The Wire reported citing internal Indian Railways data, that in 2019 around 70 to 80 cattle were hit by trains in India daily. In 2014–2015 the number of cattle that were killed due to being overrun by trains was 2000 to 3000. It increased to 14,000 in 2017–2018. In the year 2018–2019 the number had increased to nearly 30,000, a record jump. It had become "a cause of deep concern for railway authorities".
All cases of cattle colliding with the trains do not end with the death of the cattle or the derailment of the train. According to Indian Railway data, about 18,900 trains were 'cattle-hit' in 2017–2018. The cases increased and around 43,000 trains were 'cattle-hit' in 2018–2019. In the period between April–May 2019, about 5,500 'cattle run over' (CRO) cases were recorded on the tracks, which affected the running of over 7,000 trains in two months. In August 2018, Indian Express reported a 362% jump in CRO cases from 2015-16 to 2017-2018.
In February 2019, at Etawah in Uttar Pradesh, the newly-launched Vande Bharat Express on its second day of service, had hit a stray cow. The aerodynamic nose of the train, made of steel with a fibre cover on it was damaged. Similar incident happened again on 17 August 2019.
According to railway officials, 'cattle run over' events disrupt operations for several hours, as the carcass must first be cleared from the track before the train can proceed. Fencing of the railway lines with concrete reinforced barbed wire have been suggested to reduce the incidents.
Roads
Stray cows are a frequent cause of road accidents in cities, where they crowd roads. Cow attacks on pedestrians and vehicles often become deadly. Stationary cows on the road are a cause of frequent deadly road accidents in India. Cattle dung also creates a road hazard for pedestrians and two-wheeled vehicles who may slip on it.
In Tiruvallur, in 2022, emergency braking by a semi truck driver to avoid a collision with stray cattle on the road caused a multiple-vehicle collision which killed one driver. Most of the accidents related to stray cattle on the roads occur at night, when it is harder to see the animal on roads with insufficient lights.
Historian, D. N. Jha had said, "In Delhi, cows should best be treated as a safety hazard. You cannot drive safely for the cows that stray around."
Election issue
The deadly attacks by stray cows were an election issue in the 2022 Uttar Pradesh Legislative Assembly election. In 2017, after coming to power in Uttar Pradesh, the Yogi Adityanath ministry promised to build cattle shelters to better manage the stray cattle. Since then, anti-cow-slaughter laws have been strictly enforced.
The main opposition party in 2021, Samajwadi Party (SP), promised compensation of for farmers who were killed by bulls. SP promised to fix the root cause of the problem, removing the risk of trouble or harassment from the trading of livestock.
In 2022, BJP leaders denied that stray cattle was an issue, despite complaints from farmers that stray cattle were destroying crops. Speaking at a rally in Kanpur in February 2022, PM Narendra Modi acknowledged the issue in his rally and said that the Yogi government was trying to solve the problem by setting up cattle shelters.
On 22 February, local farmers released hundreds of cattle at the venue of an election rally in Barabanki located 40 km from the state capital, Lucknow. The act was to highlight the issues caused by the stray cattle in the area. In a viral video of the incident, hundreds of unattended cattle were seen roaming in the open rally ground.
Governmental response
Laws
In June 2020, the Uttar Pradesh government approved the Uttar Pradesh Cabinet Cow Slaughter Prevention (Amendment) Ordinance, 2020, that provided maximum sentences of 10 years imprisonment and fines of up to for cow slaughter.
The residents of Tiruvallur district who allow their cattle to freely wander on the roads have been warned by the police. Imprisonment of up to three years and fines up to ₹5,000 are applicable according to the provisions of the Tamil Nadu Animals and Birds in Urban Areas (Control and Regulation) Act, 1997. Police have also threatened actions according to the Indian Penal Code and Prevention of Cruelty to Animals Act, in addition the stray cattle would be sent to cow sheds operated by the government. Yet these measures have not reduced the practice of cattle owners releasing their cattle. The authorities of Tiruvallur district have also set up a call center to report incidents of stray cattle.
Cow tax
The Adityanath ministry in the state of Uttar Pradesh introduced a special 0.5% tax named the "Cow Protection Cess" on eight government departments including the department that earns revenue from alcohol taxes. The cow protection cess was levied to earn money and maintain thousands of cow sheds operated by the government. The BBC reported that the tax did not solve the problem of stray cows, and the cow sheds were found to be overcrowded. In 2019, there were 510 cow shelters in the state of Uttar Pradesh registered in the state government records.
In 2021, it was reported that the Ludhiana Municipal Corporation had collected a cow cess of ₹3.5 crore every year, for taking care of stray cows. However, as of 2021, hundreds of stray cows were seen roaming in the streets on public places in Ludhiana city.
Cow sheds
Goshalas ('cow sheds') are shelters for unproductive, homeless, unwanted or elderly cattle in India. Since the BJP government came into power in India in 2014, India has spent on cow shelters in between the years 2014 and 2016.
The BJP state government claims to have provided money to the village pradhans to set up cow shelters to keep the stray cattle. The Deccan Herald reported that it could not find cattle shelters in the villages of Sitapur, Lakhimpur Kheri, Hardoi and Unnao districts. Places that had cow shelters, were already full with no capacity to keep more cattle.
Large scale corruption has been reported in the building and management of cow shelters in Uttar Pradesh and Madhya Pradesh. The contracts for the cow shelters were awarded to people associated with the ruling party, BJP, or the Rashtriya Swayamsewak Sangh.
Cattle housed in the cow shelters often starve to death due to lack of fodder, in shelters that are not maintained properly. Overcrowded shelters lack sufficient manpower to manage the large number of cows and the money allotted to feed the cattle is not sufficient due to the over crowding.
See also
Maverick (animal)
References
External links
Human–animal interaction
Feral cattle
Animal welfare and rights in India
Animals in politics | Stray cattle in India | [
"Biology"
] | 2,089 | [
"Human–animal interaction",
"Animals",
"Humans and other species"
] |
70,148,516 | https://en.wikipedia.org/wiki/Monocrotaline | Monocrotaline (MCT) is a pyrrolizidine alkaloid that is present in plants of the Crotalaria genus. These species can synthesise MCT out of amino acids and can cause liver, lung and kidney damage in various organisms. Initial stress factors are released intracellular upon binding of MCT to BMPR2 receptors and elevated MAPK phosphorylation levels are induced, which can cause cancer in Homo sapiens. MCT can be detoxified in rats via oxidation, followed by glutathione-conjugation and hydrolysis.
Origin
MCT occurs in the seeds of certain species of the genus Crotalaria, for example, Crotalaria spectabilis and Crotalaria mucronata. MCT is a chemical with pesticide properties and therefore serves as a defence mechanism to fend off predators. However, it can also lead to the poisoning of mammals and birds.
The butterfly Utetheisa ornatrix also benefits from MCT by using it as protection. The larvae of the butterfly feed almost exclusively on Crotalaria seeds, where MCT is accumulated in their bodies. In this way, they are protected from predators such as spiders for the rest of their lives (even after pupation as butterflies).
Toxicity
MCT is an acute toxic substance. The toxicity of MCT is dose-dependent, and it can harm both organs and genetic material (genotoxicity). The organs that will be targeted are the liver (hepatotoxicity), the kidneys (nephrotoxicity) and the lungs (pneumotoxicity). MCT falls into Category 3 toxicity for oral ingestion and Category 2 toxicity for carcinogenicity according to the European Chemicals Agency (ECHA).
Studies concluded that the ingestion of MCT will cause centrilobular necrosis, pulmonary fibrosis and increase in blood urea nitrogen. These conclusions are based on the models that were used during these studies as these effects were caused in rats instead of humans. During the studies it was also concluded that mice are more resilient to MCT than rats, meaning that more mice survived the experiments than rats.
Biosynthesis of monocrotaline
The biosynthesis of MCT involves condensation of monocrotalic acid (MCA), which is derived from L-isoleucine, and retronecine, which is derived from putrescine.
MCA is formed from L-isoleucine and a synthon for propionate of uncertain origin.
Retronecine is synthesized from L-arginine via a multi-step pathway involving putrescine and spermidine intermediates:
Putrescine is converted to spermidine by addition of a propylamino group from decarboxylated S-adenosylmethioninamine (4: spermidine synthase). Spermidine and another molecule of putrescine react to form the symmetric homospermidine with loss of 1,3-diaminopropane (5: homospermidine synthase).
Oxidation (likely catalysed by 6: copper-dependent diamine oxidases) to 4,4’-iminodibutanal results into the cyclization of pyrrolizidine-1-carbaldehyde, which is reduced to 1-hydroxymethyl pyrrolizidine (likely catalysed by 7: alcohol dehydrogenase). To form the final product retronecine, 1-hydroxymethyl pyrrolizidine is desaturated and hydroxylated respectively by unknown enzymes.
MCA and retronecine are then condensed to form MCT via an unknown mechanism:
Biotransformation of monocrotaline
MCT is detoxified in rats by the liver via divergent biotransformation reactions. These reactions proceed as follows:
In Rats, MCT is first oxidised by the biotransformation enzyme cytochrome P450 (CYP) to form dehydro MCT. In this phase 1 reaction a double carbon-carbon bond is introduced out of a single carbon-carbon bond.
After the phase 1 reaction, the oxidised intermediate can either undergo hydrolysis to form monocrotalic acid and dihydropyrolizine or perform group transfer with glutathione to form MCA and a glutathione-conjugated dihydropyrolizine (GS-conjugation). These metabolites are more hydrophilic than MCT and could therefore be more easily excreted by the kidneys, which results in less exposure from MCT to the liver. The phase 2 reactions are thus classified as the detoxifying reactions during the biotransformation of MCT in rats.
During the phase 2 reactions, dehydro MCT can react with nucleophilic biological macromolecules (NuS) which is a toxic intermediate. Addition of such molecules may result into Cytotoxicity. Dehydro MCT may also undergo further toxification after hydrolysis, as dihydropyrolizine can be further oxidized to 7-dihydro-1-hydroxymethyl-5H-pyrrolizine (DHP). This intermediate can bind to DNA which may cause Genotoxicity.
Note that the biotransformation routes may differ based on the studied organism.
Mechanism of action
MCT aggregates on and activates the calcium-sensing receptor (CaSR) of pulmonary artery endothelial cells to trigger endothelial damage and, ultimately, induces pulmonary hypertension. MCT binds to the extracellular domain of the CaSR (calcium-sensing receptor). Thereby, the assembly of CaSR is enhanced and triggers the mobilisation of calcium signalling, and damages pulmonary artery endothelial cells. In addition, MCT strengthens this effect by binding to the bone morphogenetic protein receptor type II (BMPR2), which is a transmembrane receptor. BMPR2 inhibition occurs which in turn induces a blockade of BMPR1 receptor activation via phosphorylation. Inhibiting this process disturbs cell differentiation processes and ossification. Interference with these receptors induce pulmonary arterial hypertension.
MAPK is a mitogen activated protein kinase that gets activated upon BMPR2 activation. The protein kinase in turn phosphorylates p38 via a reinforced cascade of intracellular signals. It also activates p21 which has a regulating role in the cell cycle. However, MCT administration inhibits this process via a blockade of BMPR2. Cytokines such as TNF-α are released which cause activation of inflammation mechanisms, attracting neutrophils among others. Furthermore, inducible nitric oxide synthases (iNOS) are upregulated upon MCT induced cellular stress, whereas endothelial NOS (eNOS) gets downregulated. The cytokine TGF-β (also released by macrophages via chemotaxis during inflammation reactions in a positive feedback loop with TNF-α) is a transforming growth factor that is upregulated as a result of iNOS increasement, contributing to pulmonary artery proliferation. Increased levels of iNOS also stimulate caspase-3 activity which increases apoptosis levels.
See also
Oxidative stress
References
Pyrrolizidine alkaloids
Lactones
Diols | Monocrotaline | [
"Chemistry"
] | 1,571 | [
"Pyrrolizidine alkaloids",
"Alkaloids by chemical classification"
] |
70,150,688 | https://en.wikipedia.org/wiki/Winifred%20Burks-Houck | Winifred Burks-Houck (August 20, 1950 – May 6, 2004) was an environmental organic chemist and the first female president of National Organization for the Professional Advancement of Black Chemists and Chemical Engineers (NOBCChE), serving from 1993 – 2001.
Personal life
Winifred Burks-Houck was born on August 20, 1950, in Anniston, Alabama, the daughter of Mary Emma Goodson-Burks and Matthew Burks. She was the great, great, great-granddaughter of abolitionist Harriet Tubman.
Burks-Houck pledged as a member of the Delta Sigma Theta sorority as an undergraduate student at Dillard University. She served in various leadership roles during her time in alumnae chapter, holding positions as the president from 1987 – 1989, vice-president and chair of fundraising. In honor of her scientific work, Burks-Houck was named a Project Cherish Honoree at Delta Sigma Theta's 43rd annual national convention.
Education
Burks-Houck began her education in Anniston, Alabama, having attended both elementary and high school in the city. Burks-Houck continued her education and earned a Bachelor of Arts degree in chemistry from Dillard University followed by a Master of Science Degree in Organic Chemistry from Atlanta University.
Career
In 1983, Burks-Houck joined Lawrence Livermore National Laboratory, working as an environmental chemist on environmental protection projects with an interest in ensuring worker safety.
National Organization for the Professional Advancement of Black Chemists and Chemical Engineers (NOBCChE)
Burks-Houck was dedicated to the establishment of the NOBCChE on the West Coast and its national endeavours. She represented NOBCChE in Dakar, Senegal, delivering a presentation titled: "Environmental Applications and Regulatory Reporting". Starting in 1984, she worked for the San Francisco Bay Area Chapter, running development events for both professional and educational audiences. In 1991, Burks-Houck was elected as national vice president, and was elected president in 1993, becoming the first female president. Burks-Houck served as president for four terms until 2001. She worked to modernize the organization's computer systems and established new scholarships and she is credited with doubling the number of professional and student chapters. Burks-Houck was also credited with building partnerships with other organizations such as the American Association for the Advancement of Science (AAAS), American Chemical Society (ACS), American Indian Science and Engineering Alliance, National Aeronautics and Space Administration (NASA), and the Society for the Advancement of Chicanos and Native Americans in Science (SACNAS).
Death and legacy
Burks-Houck died on May 6, 2004.
In 2010, the NOBCChE created the Winifred Burks-Houck Professional Leadership Awards and Symposium. This award is given for outstanding work in the fields of science and technology to African American women.
References
1950 births
2004 deaths
American organic chemists
American women chemists
Atlanta University alumni
Delta Sigma Theta members
Dillard University alumni
Lawrence Livermore National Laboratory staff
People from Anniston, Alabama | Winifred Burks-Houck | [
"Chemistry"
] | 625 | [
"Organic chemists",
"American organic chemists"
] |
70,151,056 | https://en.wikipedia.org/wiki/LQ%20Hydrae | LQ Hydrae is a single variable star in the equatorial constellation of Hydra. It is sometimes identified as Gl 355 from the Gliese Catalogue; LQ Hydrae is the variable star designation, which is abbreviated LQ Hya. The brightness of the star ranges from an apparent visual magnitude of 7.79 down to 7.86, which is too faint to be readily visible to the naked eye. Based on parallax measurements, this star is located at a distance of 59.6 light years from the Sun. It is drifting further away with a radial velocity of 7.6 km/s.
During a 1981 survey of southern stars, W. P. Bidelman found the H and K lines of ionized calcium for LQ Hya were filled in with emission. (W. D. Heintz independently made the same observation.) In 1986, F. C. Fekel and associates determined this is a young, rapidly rotating BY Draconis-type variable. A decade of photometry was used to determine a rotation period of 1.601136 days (1 day, 14 hours, and 24 minutes) The star spots on the surface showed significant evolution over time scales of a few months. Variations in rotational modulation of surface activity suggested the star is undergoing differential rotation.
The high lithium abundance and rapid rotation of this star indicate it is a zero age main sequence star, or possibly even a pre-main sequence star. A strong flare event was observed on December 22, 1993, with an estimated energy release of . Additional flares were detected thereafter, with ROSAT X-ray data from 1992 showing a strong flare during that time period. Observations from December 2000 and 2001 showed that the magnetic field of the star is dramatically changing its topology on a time frame of a year or less.
The stellar classification of LQ Hya is K1Vp, indicating it is a K-type main-sequence star with some peculiar features in the spectrum. In some respects it is considered an analog of a young Sun around the age of 60 million years. It shows strong emission of ultraviolet and has been detected in the X-ray band, showing an X-ray emission of and indicating high chromospheric activity levels. The star shows dual magnetic activity cycles with period of 6.8 and 11.4 years, which are somewhat comparable to the solar cycle in the Sun.
References
Further reading
K-type main-sequence stars
BY Draconis variables
Solar analogs
Hydra (constellation)
BD-10 2857
082558
046816
Hydrae, LQ | LQ Hydrae | [
"Astronomy"
] | 527 | [
"Hydra (constellation)",
"Constellations"
] |
70,151,472 | https://en.wikipedia.org/wiki/Hank%20the%20Tank | Hank the Tank (also known as Henrietta) is a five-hundred-pound female American black bear that gained attention for repeated interactions with humans in the Lake Tahoe area, resulting in her eventual capture and relocation to Colorado. Known by wildlife officials as Bear 64F, Hank became a symbol of human-wildlife conflict and sparked broader discussions about bear management in populated areas.
Background
Hank, a bear local to the Tahoe Keys region of California, had been observed to frequent urban areas in 2021. The California Department of Fish and Wildlife (CDFW) observed that Hank exhibited behavior not considered normal for those in the wild with the primary example of showing a decreased fear of humans. This abnormal behavior was explained by a continuous access to food sources provided by humans, such as but not limited to open or unsecured garbage, which drew her to residential areas while searching for food.
The Lake Tahoe region has had a significant increase in the population of bears in recent years. According to the Tahoe Interagency Bear Team (TIBT), bears have been increasing their presence in the area due to overpopulation, competition for resources, and unsecured trash and bird feeders within residential zones. In the early 2000s the black bear population in Lake Tahoe was estimated to be approximately 120 bears for every 100 square kilometers, the second-highest density recorded in the US.
A result of bears having access to human food often is that they do not hibernate during winter, as is observed in around twenty percent of bears in the Lake Tahoe area. Research has shown that Wildland–urban interfaces are critical areas for human-bear interactions and potential conflicts.
Incidents
Between the years 2021 and early 2022, Hank has been associated with a series of break ins and property damage amounting to around 20 cases in the Tahoe Keys neighborhood. The media started to cover her activities as concerns about safety grew among residents. At one point, it was suspected that Hank's cases rose to as many as thirty homes. However, DNA profiling revealed that multiple bears including Hank were involved in the break-ins.
In 2022, there were a total of 902 conflict calls, 235 home invasions, and 31 permits issued on the Tahoe Basin within the borders of California. The following year, 2023, saw 660 conflict calls, 217 home invasions, and 38 permits issued. This data indicates a significant level of human-bear interaction in the region.
Relocation and management
Due to the high-profile nature of the incidents, the CDFW initially considered euthanizing Hank as a last-resort measure to address public safety concerns. However, DNA evidence indicating that multiple bears were involved prompted the agency to implement a program of tagging and monitoring bears in the region instead. No bears would be killed under this initiative, which relied on DNA sampling to track and identify individual animals associated with break-ins. On August 7, 2023, after over a year of tracking, CDFW officials successfully captured Hank and her three cubs. Hank was transported to The Wild Animal Sanctuary near Springfield, Colorado, while her cubs were placed in Sonoma County Wildlife Rescue to undergo rehabilitation. The aim was to "retrain" the cubs to rely on natural food sources and avoid human environments.
Public response
Hank's association with repeated incidents and a discussion around the possibility of euthanizing Hank generated significant public and media interest. Three wildlife sanctuaries offered to rehome Hank and saw support from the BEAR League, a local bear advocacy organization, who pledged to cover all expenses related to her relocation. Ann Bryant, executive director of the BEAR League, made comments highlighting a strong local opposition to euthanization as a solution. She underlined how Lake Tahoe residents adapted to coexisting with local wildlife and gave names to bears as a form of established community identity.
Hank was presented as a "conflict bear" in the Media due to her reliance on human food sources and frequent encounters with Tahoe locals. Her notoriety contributed to broader discussions about human-wildlife interactions, specifically giving rise to debates regarding how best to manage bear populations in urban and semi-urban areas.
Human-wildlife conflict
Hank's case brought the root cause of the human–wildlife conflict seen especially in regions like Lake Tahoe where wildlife and urban communities coexist. In recent years, bears have been becoming relatively more "habituated" to human presence, often due to unsecured garbage and intentional or accidental feeding. This habituation in time breaks their natural fear of people and can lead to increased incidents of property damage and public safety risks.
CDFW describes "conflict bears" as those that have grown accustomed to humans and having a tendency to approach them, very often requiring intervention through relocation or euthanasia. Experts have emphasized that public education on securing food sources and bear-proofing properties is crucial to reducing conflicts and protecting both humans, bear populations, and the natural dynamic of human-bear interaction. Conservationists have been arguing that the case of Hank and her cubs is a call for more effective waste management systems and awareness campaigns in areas with many bears. Authorities hope to reduce human-bear conflicts and allow bears to retain their natural avoidance of humans by promoting responsible practices such as using bear boxes and kodiak cans.
See also
List of individual bears
Human–wildlife conflict
Wildlife management
References
Individual bears
Lake Tahoe
Wildlife conservation
Animals in the United States | Hank the Tank | [
"Biology"
] | 1,093 | [
"Wildlife conservation",
"Biodiversity"
] |
70,151,929 | https://en.wikipedia.org/wiki/Insulin%20regulatory%20sequence | Transcription of insulin is regulated by the binding of various transcription factors to the ~400 base pairs before the insulin transcription start site, called the "insulin regulatory sequence". This sequence is made up of several distinct regions with different biochemical properties, each of which serve as binding sites for distinct regulatory proteins. First, multiple A/T-rich sequences, called "A elements", each of which contains a "TAAT" reocognized by homeodomain proteins. These regions are primarily bound by PDX-1, but also Cdx2 and Isl-1. Second, two so-called "C elements" – C1 located 107–118 base pairs before the transcription start site; C2 311–317 base pairs before the start site. C1 is bound by RIPE3b1 via MafA. C2 (also called the "pancreatic islet cell enhancer sequence" or "PISCES") is bound by PAX6. Third, an "E element" (two in rodents) with sequence GCCATCTG is 91–100 base pairs before the transcription start site and binds the helix-loop-helix transcription factors NEUROD1. Lastly, several "cyclic AMP response elements" with sequence TGACGTCA that binds CREB.
In humans, a "Z-element" resides 243–292 base pairs before the start site and binds a complex called ZaI, as well as PDX-1 and MafA.
References
Regulatory sequences
Insulin | Insulin regulatory sequence | [
"Chemistry"
] | 305 | [
"Gene expression",
"Regulatory sequences"
] |
70,154,420 | https://en.wikipedia.org/wiki/ZC45%20and%20ZXC21 | ZC45 and ZXC21, sometimes known as the Zhoushan virus, are two bat-derived strains of severe acute respiratory syndrome–related coronavirus. They were collected from least horseshoe bats (Rhinolophus pusillus) by personnel from military laboratories in the Third Military Medical University (Chongqing, China) and the Research Institute for Medicine of Nanjing Command (Nanjing, China) between July 2015 and February 2017 from sites in Zhoushan, Zhejiang, China, and published in 2018. These two virus strains belong to the clade of SARS-CoV-2, the virus strain that causes COVID-19, sharing 88% nucleotide identity at the scale of the complete virus genome.
References
SARS-CoV-2
Bat virome
Coronaviridae
Animal virology
Sarbecovirus
Zoonoses | ZC45 and ZXC21 | [
"Biology"
] | 171 | [
"Virus stubs",
"Viruses"
] |
70,154,460 | https://en.wikipedia.org/wiki/Mia%20Krisna%20Pratiwi | Mia Krisna Pratiwi (born 19 June 1996) is an Indonesian Environmental engineer and environmentalist. In 2021, she was listed as one of BBC's 100 Women.
Pratiwi attended the Bandung Institute of Technology and works at the Denpasar City Environmental Agency. Pratiwi developed a computer application to improve the collection, processing and recycling of urban waste on the island of Bali. It is managed through the NGO Griya Luhu and involves the local community.
In October 2021, Pratiwi was on the jury for the Sustainable Teenpreneur Competition.
References
1996 births
Living people
People from Bali
Environmental engineers
Indonesian women environmentalists
21st-century Indonesian women
21st-century Indonesian engineers
Bandung Institute of Technology alumni
Indonesian women engineers
21st-century women engineers | Mia Krisna Pratiwi | [
"Chemistry",
"Engineering"
] | 157 | [
"Environmental engineers",
"Environmental engineering"
] |
70,155,208 | https://en.wikipedia.org/wiki/SCIFiRE | SCIFIRE, or the Southern Cross Integrated Flight Research Experiment, is an American-Australian military technology partnership that is developing a solid-rocket-boosted, air-breathing, hypersonic conventionally-armed cruise missile that can be launched by existing fighter or bomber aircraft.
History
The project is led by the United States Department of Defense and the Australian Department of Defence. The United States Air Force, United States Navy, the Royal Australian Air Force Headquarters, and the Australian Defence Science and Technology Group are working with contractors Boeing, Lockheed Martin, and Raytheon Technologies.
The project is an "outgrowth" of the 2007-initiated HIFiRE project, which involved the same partners and explored scramjet engine technology and tested the flight dynamics of a Mach-8 hypersonic glide vehicle. SCIFiRE officially commenced in November 2020. The missile will be capable of Mach 5 speed and will be suitable for launching from an F/A-18F Super Hornet, EA-18G Growler, F-35A Lightning II, or a P-8A Poseidon maritime surveillance aircraft. Flight testing is expected to occur in the RAAF Woomera Range Complex in South Australia.
As of 2021, the missile was expected to enter service within 5 to 10 years. The Australian Government considers the missile to be a potential deterrent to would-be aggressors in the Pacific region.
The follow-on tactical-range Hypersonic Attack Cruise Missile (HACM) will be built by Raytheon Technologies and will use a Northrop Grumman scramjet.
References
Hypersonic cruise missiles
Proposed weapons of the United States
Proposed weapons
Australia–United States military relations | SCIFiRE | [
"Astronomy"
] | 334 | [
"Rocketry stubs",
"Astronomy stubs"
] |
59,357,551 | https://en.wikipedia.org/wiki/Whitworth%20Society | The Whitworth Society was founded in 1923 by Henry Selby Hele-Shaw, then president of the Institution of Mechanical Engineers. Its purposes are to promote engineering in the United Kingdom, and more specifically to support all Whitworth Scholars, the recipients of a scholarship funded by Joseph Whitworth's scholarship scheme, which started in 1868. A Whitworth Scholar is the result of completing a successful Whitworth Scholarship. Membership of the Society is limited to Whitworth Scholars, Senior Scholars, Fellows, Exhibitioners and Prizemen. The Society is a way for making contact with all successful "Whitworths" and provides a way for making information contacts and connections from more senior members to recently successful Scholars. The Society also serves as a way to commemorate Joseph Whitworth and acknowledge his contributions to engineering education.
Activities
Commemorative dinner and annual general meeting
The annual dinner and annual general meeting is held on the evening of 18 March (or nearest Friday to) to commemorate the date in 1868 when Joseph Whitworth wrote to Benjamin Disraeli, offering to found the Whitworth Scholarships. Traditionally the dinner has been held in London until more recent times where the meal and meeting is alternated, one-year London and one-year Manchester.
Summer meeting
There is a summer meeting held over two-days normally at the beginning of July. The event is largely informal and ordinarily arranged by the President of the Society.
Record
A record of all scholars is kept by the Society, until recent years, this was in hardback form (see image) presented when an individual was elected a scholar. In recent times, the register is kept electronically and provided by USB flash drive as part of the awards ceremony.
Whitworth Scholarship
A Whitworth Scholarship, named after Joseph Whitworth, is an "award for outstanding engineers, who have excellent academic and practical skills and the qualities needed to succeed in industry, to take an engineering degree-level programme in any engineering discipline".
Background
On 18 March 1868, Joseph Whitworth wrote to then Prime Minister Benjamin Disraeli to fund 30 scholarships for the value of £100 for young men in the United Kingdom. This was met favourably by the Government at the time as minuted on 27 March 1868 by the council. After the adoption of this by Government, Whitworth presented a memorandum setting out the requirements of the awards which included examinations in mathematics, mechanics, physics, and chemistry, including metallurgy and in the following handicrafts: Smith's Work, turning, filing, fitting, pattern making and moulding.
Whitworth's intent was to support those individuals with practical skills, training, typically those who today have completed an apprenticeship who had the desire to continue onto further, higher education, university degree courses. The Scholarships continue over 150-years after inception of the idea. In 2018 the prize money awarded is up to £5,450 per annum for an undergraduate programme and £8,250 per annum for a post graduate research programme. The prize money is still funded by the original money provided in Trust by Joseph Whitworth.
The criteria for a scholarship remains consistent with the original mandate of 1868, practical skills with aptitude for science and mathematic based academia. In 2018, the conditions for application for a scholarship are to:
Have pursued a vocational training route (i.e. apprenticeship) in an engineering discipline typically for at least 2 years after having left full-time education (generally UK secondary education or college based study) and before entering a degree-level engineering course.
Have obtained or will obtain an appropriate qualification for admission to the planned engineering degree-level programme of any engineering discipline.
Be British, Commonwealth or European Union citizen, and resident in the UK for at least 3 consecutive years immediately prior to undertaking study in the UK at a College of FE/HE or university
In 1984, as a result of consultation with the Whitworth Society, the administration of the Awards and Scholarship programmes was transferred from the Department of Education & Science (at the time) to the Institution of Mechanical Engineers.
Current scholarship
Today, the scholarship programme lasts for the duration of an individual's academic studies, typically 3–4 years of full-time degree studies. During this time, the individuals are termed "award holders".
If the continued monitoring of progress and overall academic achievement is deemed satisfactory, the award holder becomes a Whitworth Scholar. This occasion is commemorated at the Institution of Mechanical Engineers Vision Awards ceremony ordinarily carried out in the September/October period of each year.
Whitworth Scholar
A Whitworth Scholar is the accolade given to those who have successfully completed a Whitworth Scholarship. It is rare on the basis that only a small number of scholarships are issued each year which has quite specific application conditions and a tough review process.
A Whitworth Scholar is permitted to use the post-nominal letters, WhSch.
Typically there is an awards ceremony for the successful scholars where a certificate and medal (shown opposite) are presented. In recent years forms part of the IMechE's vision awards in September/October time each year.
Post nominals
There are recognised post-nominals which are permitted to be used after an individual's name. They are as follows.
Officers
See also
List of mechanical engineering awards
References
Engineering education in the United Kingdom
Mechanical engineering awards
Mechanical engineering organizations
1923 establishments in the United Kingdom
Scientific organisations based in the United Kingdom
Scientific organizations established in 1923 | Whitworth Society | [
"Engineering"
] | 1,109 | [
"Mechanical engineering awards",
"Mechanical engineering",
"Mechanical engineering organizations"
] |
59,359,688 | https://en.wikipedia.org/wiki/Airbus%20RACER | The Airbus RACER (Rapid and Cost-Effective Rotorcraft) is an experimental high-speed compound helicopter developed by Airbus Helicopters from the Eurocopter X³.
It was revealed at the June 2017 Paris air show, final assembly slated to start in mid-2020 for a 2021 first flight. Actual first flight was in 2024.
Cruising up to , it aims for a 25% cost reduction per distance over a conventional helicopter.
Development
On 20 June 2017 at the Paris air show, Airbus Helicopters revealed a high-speed demonstrator configuration based on the X3
developed within the Clean Sky 2 research programme.
Its aerodynamic configuration was validated in 2017.
In February 2018, the Safran Aneto-1X power plant was selected over the RTM322 initially selected, it is 25% more compact for the same power.
By October 2018, design of key subsystems was completed before the first components started manufacturing with long-lead items, as the lateral drive shaft production began.
GE's Avio Aero in Italy launched procurement and manufacturing of the lateral gear boxes housings, GE Aviation Systems in UK is building the wing’s titanium cradle, INCAS/Romaero in Romania started the design and manufacturing the hybrid structure (metal & composite) of the Main Fuselage and the Firewalls and Aernnova in Spain the tail parts primary structure.
The flight demonstration should expand the flight envelope and assess performance, before demonstrating missions like EMS, SAR and private transport, while developing low-noise flight procedures.
Final assembly was due to start in mid-2020 for a first flight in the fourth quarter of 2021 however, primarily due to COVID-19 pandemic-related delays, only 50% of the components were completed by the spring of 2021. The final component, the gearbox, was expected to be delivered in Q1 2022 for ground testing and installation, with first flight anticipated at the beginning of Q2 in 2022. It only arrived in March 2023 while powered systems testing and taxi trials however had begun in December 2022.
It made its first flight on 25 April 2024 in Marignane.
By its third test flight in May, it had performed aggressive manoeuvres and reached 165 kn (305 km/h), using less power than a conventional helicopter, while both engines were at 50% torque at .
It should reach later in 2024 and the “eco-mode” with one engine shut down in cruise should be flight tested in 2025, along mission demonstrations.
Design
Optimised for a cruise over , 50% faster than a conventional helicopter, it will consume 15% less fuel per distance at than a helicopter at , and aim for a 25% cost reduction per distance.
The lateral pusher propellers generate thrust and are isolated from passengers during ground operations by the box wings which serve to generate lift at cruise velocity. This allows the main rotor to be slowed by up to 15% as the craft's air speed increases and prevents the rotor blades breaking the sound barrier which would reduce performance.
Driven by two engines, of which one is capable of shutting down and restarting once inflight to save fuel and increase range, it will have a low weight and low maintenance hybrid metallic-composite airframe and lower weight high voltage direct current electrical generation.
Specifications
See also
References
Airbus Helicopters aircraft
Compound helicopters
Experimental helicopters
Twin-turbine helicopters
Slowed rotor | Airbus RACER | [
"Engineering"
] | 683 | [
"Slowed rotor",
"Aerospace engineering"
] |
59,361,584 | https://en.wikipedia.org/wiki/Bor-ming%20Jahn | Bor-ming Jahn (; 24 August 1940 – 1 December 2016) was a Taiwanese-French geochemist.
Life and career
Born in Miaoli, Taiwan, on 24 August 1940, Jahn graduated from Hsinchu Senior High School and attended National Taiwan University, where, in 1963, he earned a bachelor's degree in geology. He obtained a master's degree in geochemistry from Brown University in 1967, and completed a Ph.D. at the University of Minnesota in 1972.
After postdoctoral work and further research at NASA and the Lunar Science Institute, Jahn moved to France and joined the University of Rennes I faculty in 1976. Jahn acquired French nationality in May 1980. In 2003, he returned to Taiwan, serving as distinguished research fellow affiliated with the Institute of Earth Sciences, Academia Sinica from August 2004 to 2010. He left Academia Sinica to take an appointment at NTU, as distinguished chair professor of the department of geosciences. Between 2006 and 2016, Jahn was chief editor of the Journal of Asian Earth Sciences.
Over the course of his career, Jahn was granted fellowship by the Mineralogical Society of America and Geological Society of America in 2004, followed by the Geochemical Society and European Association of Geochemistry in 2006. In 2012, Jahn was elected a member of Academia Sinica. The next year, the French government named Jahn a chevalier of the ordre des Palmes Académiques. In 2016, the Geological Society of America awarded Jahn honorary fellow status. He died on 1 December 2016, at the Taipei Veterans General Hospital.
References
1940 births
2016 deaths
21st-century Taiwanese scientists
Taiwanese geochemists
Taiwanese emigrants to France
Naturalized citizens of France
French geochemists
National Taiwan University alumni
Academic staff of the National Taiwan University
Academic staff of the University of Rennes
Members of Academia Sinica
Fellows of the Geological Society of America
Academic journal editors
Chevaliers of the Ordre des Palmes Académiques
People from Miaoli County
20th-century Taiwanese scientists
20th-century geologists
21st-century geologists
20th-century French chemists
21st-century French chemists
Brown University alumni | Bor-ming Jahn | [
"Chemistry"
] | 437 | [
"Geochemists",
"French geochemists",
"Taiwanese geochemists"
] |
59,361,833 | https://en.wikipedia.org/wiki/Operation%20Helvetic | Operation Helvetic is the operational name for the British Armed Forces' residual operation in Northern Ireland from July 2007 to the present day.
Background
It was the successor operation to Operation Banner after the end of The Troubles. It consists primarily of support from Ammunition technical officers for the Police Service of Northern Ireland against an ongoing threat of bomb attacks from republican and loyalist dissidents. The operation is also intended to provide military support to the PSNI in the event of serious public disorder or an environmental crisis.
At the start of the operation the total British army strength was approximately 5,000 soldiers in ten locations. By 2018 this had reduced to around 1,300 troops only for training purposes. Thus far two British soldiers have been killed by republican paramilitaries during the operation, both killed in the 2009 Massereene Barracks shooting.
In 2016 ATOs serving as part of Operation Helvetic dealt with terrorist bomb alerts roughly once a week. Of these 49% were classified as "serious threats". The lack of a General Service Medal for ATOs serving as part of Operation Helvetic was the subject of controversy in 2017 following the rejection by the cabinet office of a request for the award of the GSM to ATOs from Andrew Rowe, Northern Ireland's most senior army officer.
In 2018 the operation was the subject of a freedom of information request brought by the Committee on the Administration of Justice, which was seeking the disclosure of the terms of reference for Operation Helvetic. The request was opposed by the UK ministry of defence on grounds of operational secrecy. Though the Information Commissioner's Office found against the MoD, the MoD plans to appeal the decision.
The cost of Operation Helvetic was approximately £1 billion a year in 2019. By 2019 increasing numbers of specialist troops were being deployed as part of the operation due to an uptick in the activity of Republican dissidents.
References
British Army deployments
Military history of Northern Ireland
Helvetic
Bomb disposal | Operation Helvetic | [
"Chemistry"
] | 401 | [
"Explosion protection",
"Bomb disposal"
] |
59,361,953 | https://en.wikipedia.org/wiki/NGC%207184 | NGC 7184 is a barred spiral galaxy located in the constellation Aquarius. It is located at a distance of circa 100 million light years from Earth, which, given its apparent dimensions, means that NGC 7184 is about 175,000 light years across. It was discovered by William Herschel on October 28, 1783.
Characteristics
NGC 7184 has a small, bright nucleus and an elliptical bulge, whose major axis is aligned with the major axis of the disk. There is a bar along the minor axis of the bulge, but the high inclination of the galaxy makes its presence uncertain. From the bar emanate two tightly wound symmetrical spiral arms that form a bright inner ring. The diameter of the ring along its major axis is 1.71 arcminutes. The arms feature HII regions, and as they emerge from the ring are flocculent, based on the HII distribution, while they begin to split again at the outermost part of the galaxy. Dust lanes are observed in the inner part of the disk.
An outlying HII region has been discovered near NGC 7184. It is located on the major axis of the optical disk, on the northeasterly receding edge. Its size is estimated to be 270 pc at the distance of the galaxy and its Hα luminosity, 1037.6 erg s−1. It could be an isolated extension of a spiral arm.
Supernova
One supernova has been observed in NGC 7184, SN 1984N. It was discovered visually by Robert Evans at magnitude 14, 60" east and 65" north of the nucleus on July 20, 1984. Its discovery was confirmed by T. Cragg at the Anglo-Australian Observatory. Initially it was thought to be a variable star in our galaxy, but later study of the object revealed it was indeed a supernova. It was identified as type I.
Nearby galaxies
NGC 7184 is the foremost galaxy of a small galaxy group known as the NGC 7184 group, which also includes NGC 7183. A satellite galaxy lies 3 arcminutes to the south, at a projected separation of 28 kpc.
References
External links
Barred spiral galaxies
Aquarius (constellation)
7184
UGCA objects
67904
Discoveries by William Herschel
Astronomical objects discovered in 1783 | NGC 7184 | [
"Astronomy"
] | 470 | [
"Constellations",
"Aquarius (constellation)"
] |
59,362,417 | https://en.wikipedia.org/wiki/Sustainability%20in%20construction | Sustainable construction aims to reduce the negative health and environmental impacts caused by the construction process and by the operation and use of buildings and the built environment. It can be seen as the construction industry's contribution to more sustainable development. Precise definitions vary from place to place, and are constantly evolving to encompass varying approaches and priorities. More comprehensively, sustainability can be considered from three dimension of planet, people and profit across the entire construction supply chain. Key concepts include the protection of the natural environment, choice of non-toxic materials, reduction and reuse of resources, waste minimization, and the use of life-cycle cost analysis.
Definition of sustainable construction
One definition of "Sustainable Construction" is the introduction of healthy living and workplace environments, the use of materials that are sustainable, durable and by extension environmentally friendly. In the United States, the Environmental Protection Agency (EPA) defines sustainable construction as "the practice of creating structures and using processes that are environmentally responsible and resource-efficient throughout a building's life-cycle from siting to design, construction, operation, maintenance, renovation and deconstruction." Agyekum-Mensah et al. note that some definitions of sustainable construction and development "seem to be vague" and they question use of any definition of "sustainability" which suggests that sustainable or acceptable activities can be continued indefinitely, because construction projects do not run on indefinitely.
Evolution path
In the 1970s, awareness of sustainability emerged, amidst oil crises. At that time, people began to realize the necessity and urgency of energy conservation, which is to utilize energy in an efficient way and find alternatives to contemporary sources of energy. Additionally, shortages of other natural resources at that time, such as water, also raised public attention to the importance of sustainability and conservation. In the late 1960s, the construction industry began to explore ecological approaches to construction, aiming to seek harmony with nature.
The concept of sustainable construction was born out of sustainable development discourse. The term sustainable development was first coined in the Brundtland report of 1987, defined as the ability to meet the needs of all people in the present without compromising the ability of future generations to meet their own. This report defined a turning point in sustainability discourse since it deviated from the earlier limits-to-growth perspective to focus more on achieving social and economic milestones, and their connection to environmental goals, particularly in developing countries. Sustainable development interconnects three socially concerned systems—environment, society and economy—a system seeking to achieve a range of goals as defined by the United Nations Development Program.
The introduction of sustainable development into the environmental/economical discourse served as a middle ground for the limits-to-growth theory, and earlier pro-growth theories that argued maintaining economic growth would not hinder long-term sustainability. As a result, scholars have faulted sustainable development for being too value-laden since applications of its definition vary heavily depending on relevant stakeholders, allowing it to be used in support of both pro-growth and pro-limitation perspectives of development arguments despite their vastly different implications. In order for the concept to be effective in real-life applications, several specified frameworks for its use in various fields and industries, including sustainable construction, were developed.
The construction industry's response to sustainable development is sustainable construction. In 1994, the definition of sustainable construction was given by Professor Charles J. Kibert during the Final Session of the First International Conference of CIB TG 16 on Sustainable Construction as "the creation and responsible management of a healthy built environment based on resource efficient and ecological principles". Notably, the traditional concerns in construction (performance, quality, cost) are replaced in sustainable construction by resource depletion, environmental degradation and healthy environment. Sustainable construction addresses these criteria through the following principles set by the conference:
Minimize resource consumption (Conserve)by effective procurment systems and strategies
Maximize resource reuse (Reuse)
Use renewable or recyclable resources (Renew/Recycle/Repurpose
Protect and incorporate the natural environment (Protect Nature)
Create a healthy, non-toxic environment (Non-Toxics)
Pursue quality in creating the built environment (Quality)
Additional definitions and frameworks for sustainable construction practices were more rigorously defined in the 1999 Agenda 21 on Sustainable Construction, published by the International Council for Research and Innovation in Building and Construction (CIB). The same council also published an additional version of the agenda for sustainable construction in developing countries in 2001 to counteract biases present in the original report as a result of most contributors being from the developed world.
Since 1994, much progress to sustainable construction has been made all over the world. According to a 2015 Green Building Economic Impact Study released by U.S. Green Building Council (USGBC), the green building industry contributes more than $134.3 billion in labor income to working Americans. The study also found that green construction's growth rate is rapidly outpacing that of conventional construction and will continue to rise.
Goals of sustainable construction
Current state
According to United Nations Environment Programme (UNEP), "the increased construction activities and urbanization will increase waste which will eventually destroy natural resources and wild life habitats over 70% of land surface from now up to 2032. " Moreover, construction uses around half of natural resources that humans consume. Production and transport of building materials consumes 25 - 50 percent of all energy used (depending on the country considered). Taking UK as an example, the construction industry counts for 47% of emissions, of which manufacturing of construction products and materials accounts for the largest amount within the process of construction.
Benefits
By implementing sustainable construction, benefits such as lower cost, environmental protection, sustainability promotion, and expansion of the market may be achieved during the construction phase. As mentioned in ConstructionExecutive, construction waste accounts for 34.7% of all waste in Europe. Implementing sustainability in construction would cut down on wasted materials substantially.
Potential lower cost
Sustainable construction might result in higher investment at the construction stage of projects, the competition between contractors, due to the promotion of sustainability in the industry, would encourage the application of sustainable construction technologies, ultimately decreasing the construction cost. Meanwhile, the encouraged cooperation of designer and engineer would bring better design into the construction phase.
Using more sustainable resources reduces cost of construction as there will be less water and energy being used for construction and with less resources being used in the projects, it would lead to lower disposal costs as there is less waste being made.
Environment protection
By adopting sustainable construction, contractors would make the construction plan or sustainable site plan to minimize the environmental impact of the project. According to a study took place in Sri Lanka, considerations of sustainability may influence the contractor to choose more sustainable, locally sourced products and materials, and to minimize the amount of waste and water pollution. Another example is from a case study in Singapore, the construction team implemented rainwater recycling and waste water treatment systems that help achieve a lower environmental impact.
Promoting sustainability
According to "Sustainable Construction: Reducing the Impact of Creating a Building", the contractor in collaboration with the owner would deliver the project in a sustainable way. More importantly, the contractor would have known this was a key performance indicator for the client from day one, allowing them the opportunity to not tender for the work, should this not appeal to them. Moreover, "It also sends a clear message to the industry, 'sustainability is important to us' and this, especially within the government and public sectors can significantly drive change in the way projects are undertaken, as well as up-skilling the industry to meet this growing demand.
Expand market
By promoting sustainable methods and products in daily work, the good result directly shows the public the positive effect of sustainable construction. Consequently, there would be potential to expand the market of sustainable concepts or products. According to a report published by USGBC, "The global green building market grew in 2013 to $260 billion, including an estimated 20 percent of all new U.S. commercial real estate construction."
Sustainable construction strategies
Globally, construction industries are attempting to implement sustainable construction principles. Below are some examples of successful implementations of sustainable construction promotion on a national level. Also included are new technologies that could improve the application of sustainable construction.
Strategic Policy and Guide
Creation of a national strategy to improve the development: the government of Singapore announced a Sustainable Singapore Blueprint in April 2009, launching a long-term strategy of sustainable construction development. Another example is Strategy for sustainable construction in the UK.
Investing money on research and education : S$50 million "Research Fund for the Built Environment" was launched in 2007 by Singapore Government to kick-start R&D efforts in sustainable development.
Guidance for sustainable application: Government department cooperating with academic institutes to make an industrial guide for workers, for example, the Field Guide for Sustainable Construction published in 2004.
Changing Mindset in the Way of Development
The Government in Singapore has developed a Sustainable Construction Master Plan with the hope to transform the industrial development path from only focusing on the traditional concerns of "cost, time, and quality" to construction products and materials, to reduce natural resource consumption and minimize waste on site. With the expediting concern of the climate crisis, it is essential to keep in mind the importance of reducing energy consumption and toxic waste whilst moving forward with sustainable architectural plans.
New Technologies
The development of efficiency codes has prompted the development of new construction technologies and methods, many pioneered by academic departments of construction management that seek to improve efficiency and performance while reducing construction waste.
New techniques of building construction are being researched, made possible by advances in 3D printing technology. In a form of additive building construction, similar to the additive manufacturing techniques for manufactured parts, building printing is making it possible to flexibly construct small commercial buildings and private habitations in around 20 hours, with built-in plumbing and electrical facilities, in one continuous build, using large 3D printers. Working versions of 3D-printing building technology are already printing of building material per hour , with the next-generation printers capable of per hour, sufficient to complete a building in a week. Dutch architect Janjaap Ruijssenaars's performative architecture 3D-printed building was scheduled to be built in 2014.
Over the years, the construction industry has seen a trend in IT adoption, something it always found hard to compete with when paired against other fields such as, the manufacturing or healthcare industries. Nowadays, construction is starting to see the full potential of technological advancements, moving on to paperless construction, using the power of automation and adopting BIM, the internet of things, cloud storage and co-working, and mobile apps, implementation of surveying drones, and more.
In the current trend of sustainable construction, the recent movements of New Urbanism and New Classical architecture promote a sustainable approach towards construction, that appreciates and develops smart growth, architectural tradition and classical design. This is in contrast to modernist and short-lived globally uniform architecture, as well as opposing solitary housing estates and suburban sprawl. Both trends started in the 1980s.
Timber is being introduced as a feasible material for skyscrapers (nicknamed "plyscrapers") thanks to new developments incorporating engineered timber, whose collective name is "mass timber" and includes cross-laminated timber.
Industrial hemp is becoming increasingly recognised as an eco-friendly building material. It can be used in a range of ways, including as an alternative to concrete (known as 'hempcrete'), flooring, and insulation. King Charles is reported to have used hemp to insulate an eco-home. In December 2022, the United Nations Conference on Trade and Development (UNCTAD) emphasised hemp's versatility and sustainability, and advocated its use as a building material, in a report entitled 'Commodities at a glance: Special issue on industrial hemp'.
Sustainable construction in developing countries
Specific parameters are needed for sustainable construction projects in developing countries. Scholar Chrisna Du Plessis of the Council for Scientific and Industrial Research (CSIR) defines the following key issues as specific to work in developing countries:
New, non-western frameworks for development
Understanding the connection between urbanization and rural development
Sustainable housing solutions
Education
Innovative materials
Innovative methods of construction
Merging modern and traditional practices
Promoting equity in gender roles
Development of new financing systems
Improving the capacity of the government and the construction industry
In a later work, Du Plessis furthers the definition for sustainable construction to touch on the importance of sustainability in social and economic contexts as well. This is especially relevant in construction projects in the Global South, where local value systems and social interactions may differ from the western context in which sustainable construction frameworks were developed.
Debates surrounding sustainable construction in developing countries
First, the need for sustainable development measures in developing countries is considered. Most scholars have reached a consensus on the concept of the 'double burden' placed on developing countries as a result of the interactions between development and the environment. Developing countries are uniquely vulnerable to problems of both development (resource strain, pollution, waste management, etc.) and under-development (lack of housing, inadequate water and sanitation systems, hazardous work environments) that directly influence their relationship with the surrounding environment. Additionally, scholars have defined two classes of environmental problems faced by developing countries; 'brown agendas' consider issues that cause more immediate environmental health consequences on localized populations, whereas 'green agendas' consider issues that address long-term, wide-scope threats to the environment. Typically, green agenda solutions are promoted by environmentalists from developed, western countries, leading them to be commonly criticized as being elitist and ignorant to the needs of the poor, especially since positive results are often delayed due to their long-term scope. Scholars have argued that sometimes these efforts can even end up hurting impoverished communities; for example, conservation initiatives often lead to restrictions on resource-use despite the fact that many rural communities rely on these resources as a source of income, forcing households to either find new livelihoods or find different areas for harvesting. General consensus is that the best approaches to sustainable construction in developing countries is through a merging of brown and green agenda ideals.
Stakeholders
Foreign investors and organizations
Since all of the definitions and frameworks for the major concepts outlined previously are developed by large international organizations and commissions, their research and writings directly influence the organization, procedures, and scale of rural development projects in the Global South. Attempts at community development by foreign organizations like the ones discussed have questionable records of success. For instance, billions of dollars of aid have flowed into Africa over the past 60 years in order to address infrastructure shortcomings, yet this aid has created numerous social and economic problems without making any progress toward infrastructure development. One compelling explanation for why infrastructure projects as a result of foreign aid have failed in the past is that they are often eurocentric in modelling and applied off successful strategies used in western countries without adapting to local needs, environmental circumstances and cultural value systems.
NGOs/Non-profits
Often NGOs and development nonprofits are criticized for taking over responsibilities that are traditionally carried out by the state, causing governments to become ineffective in handling these responsibilities over time. Within Africa, NGOs carry out the majority of sustainable building and construction through donor-funded, low-income housing projects.
Future development
Currently, sustainable construction has become mainstream in the construction industry. The increasing drive to adopt a better way of construction, stricter industrial standards and the improvement of technologies have lowered the cost of applying the concept, according to Business Case For Green Building Report. The current cost of sustainable construction may be 0.4% lower than the normal cost of construction.
See also
Alternative natural materials
Autonomous building
Biophilic design
Development Fund of the Swedish Construction Industry
Ecological design
Energy-efficient landscaping
Environmental engineering
Environmental surveying
Green building
Hempcrete
Natural building
Sustainable architecture
References
Construction
Sustainability | Sustainability in construction | [
"Engineering"
] | 3,182 | [
"Construction"
] |
59,363,707 | https://en.wikipedia.org/wiki/M.%20A.%20Sargent%20Medal | The M. A. Sargent Medal is awarded by Engineers Australia for longstanding eminence in science or the practice of electrical engineering. It is named in honour of Michael Anthony (Mike) Sargent, an outstanding Australian electrical engineer. The medal is the highest award of the Electrical College board of Engineers Australia.
Recipients
Source: Engineers Australia
1989 Stuart G. Lister, State Electricity Commission of Queensland
1990 Graham Goodwin, University of Newcastle, Australia
1991 John Ness, MITEC Ltd
1992 W. Derek Humpage, University of Western Australia
1993 W. John Edwards, Industrial Automation Services Pty Ltd
1994 Martin Green, University of New South Wales
1995 Rodney Tucker, University of Melbourne
1996 Else Shepherd, Powerlink Queensland
1997 John Hullett, Curtin University
1998 John Richard (Rick) Gumley, Erico Lightning Technologies
1999 Michael Miller, University of South Australia
2000 Mark Sceats, University of Sydney
2001 No award
2002 Brian D. O. Anderson, Australian National University
2003 Henry d'Assumpcao, Defence Science and Technology Organisation
2004 Richard Middleton, University of Newcastle, Australia
2005 Noel Godfrey, Hatch Associates
2006 Barry Inglis, CSIRO
2007 Vic Gosbell, University of Wollongong
2008 Keith Hilless, Zerogen Pty Ltd
2009 No award
2010 David James Skellern, Macquarie University
2011 Paul Wilson, Queensland University of Technology
2012 Trevor S. Bird, CSIRO
2013 John O'Sullivan, CSIRO
2014 Don Sinnott, Defence Science and Technology Organisation
2015 David Sweeting University of Wollongong and Alex Zelinsky, Defence Science and Technology Organisation
2016 Alan Finkel, Office of the Chief Scientist (Australia)
2017 Hugh Durrant-Whyte, The University of Sydney
2018 Xinghuo Yu, RMIT University
2019 Derek Abbott, University of Adelaide
2020 Ian Hiskens, University of Michigan
2021 Ian Webster, Ampcontrol P/L and Qing-Long Han, Swinburne University
2022 Tapan Saha, University of Queensland and Peng Shi, University of Adelaide
2023 Lachlan Blackhall Australian National University
2024 Mahdi Jalili, RMIT University
See also
List of engineering awards
List of awards named after people
References
Australian science and technology awards
Engineering awards
Awards established in 1989 | M. A. Sargent Medal | [
"Technology"
] | 451 | [
"Science and technology awards",
"Engineering awards"
] |
59,371,126 | https://en.wikipedia.org/wiki/Yuki%20Okoda | Yuki Okoda is a Japanese astronomer. She made headlines while she was a physics graduate student in her 2nd year of Masters at the University of Tokyo's School of Science. Okoda found a dense disk of material around a young star, which may be a precursor of a planetary system. The star in question is known by its catalogue number IRAS 15398-3359.
Okoda and her colleagues are researching the formation of planetary systems through radio-wave observation using the Atacama Large Millimeter Array (ALMA) in Chile.
In 2018 Okoda was named one of the 100 influential women in the world by the BBC.
Publications
Yuki Okoda, Yoko Oya, Nami Sakai, Yoshimasa Watanabe, Jes K. Jørgensen, Ewine F. Van Dishoeck, and Satoshi Yamamoto. The Co-evolution of Disks and Stars in Embedded Stages: The Case of the Very-low-mass Protostar IRAS 15398-3359 - Astrophysical Journal Letters
References
Living people
1990s births
21st-century Japanese astronomers
Women astronomers
21st-century Japanese women scientists | Yuki Okoda | [
"Astronomy"
] | 228 | [
"Women astronomers",
"Astronomers"
] |
59,371,888 | https://en.wikipedia.org/wiki/FinnGen | The FinnGen project was launched in 2017 with the aim of collecting biological samples from 500,000 participants in Finland over six years with the aim of improving health through genetic research. This is about 10% of the population. It is hoped that it will be a springboard for better diagnostics and new therapies. It is the key to Finland's Health Sector Growth Strategy for Research and Innovation Activities.
Activity
It is a public–private partnership between Finnish universities, the National Institute for Health and Welfare, the Finnish Red Cross Blood Service, the biobanks, which are mostly owned by independent hospital districts, hospitals, and pharmaceutical companies including Abbvie, AstraZeneca, Biogen, Celgene, Genentech, GSK, Janssen, Maze Therapeutics, Merck, Novartis, Pfizer, and Sanofi. It has funding of approximately €80 million, some of which has come from the companies. €20 million has come from Business Finland. 500,000 blood samples are to be collected over six years by a nation-wide network of Finnish biobanks and they will be matched with national health records, 98% of which are available in an electronic format. It claims that it will manage the anonymous health registry and the genomic data without compromising the privacy and integrity of participants.
The study is using Thermo Fisher Scientific's Axiom Genotyping Solution. In February 2021, the FinnGen data resource contained data from more than 321,000 biobank sample donors.
DNA samples had already been collected from about 230,000 Finns for earlier studies. The 2013 Biobank Act permitted samples to be transferred to biobanks and made available to researchers. These earlier samples were collected from people who are now getting older, so they can be related to many more disease events than the UK Biobank. The concept of ‘broad consent’ means that participants do not have to be asked to consent for their samples to be used in each project. The Finnish Biobank Cooperative was established in 2017. The first summary of results was released to the public on January 14, 2020 and will be updated every 6 months, at a one year delay with the internal findings.
History
Finnish people descend from a small founder population with little consanguinity. The low level of variants in the population structure means the chances that any disease association findings will have statistical significance are greater. Genetic discoveries can be made more easily than in more heterogeneous populations.
References
Biobank organizations
Biological databases
Medical and health organisations based in Finland | FinnGen | [
"Biology"
] | 520 | [
"Bioinformatics",
"Biological databases"
] |
59,372,590 | https://en.wikipedia.org/wiki/Wheatstone%20Corporation | Wheatstone Corporation is an American company that produces digital and analog professional audio equipment for broadcast radio, television, and new media. Products include audio consoles, Audio over IP (AoIP) audio networking, audio processing, audio recording and editing, and custom furniture. The corporation also does business under the brand names Audioarts Engineering, Pacific Research & Engineering, and VoxPro.
Founder
Gary Snow’s interest in audio came early: “By age 12, I was running a neighborhood radio and TV repair shop. I built my first stereo system at 15 and then moved on to guitar amps and loudspeaker enclosures,” Snow said. After high school, Gary took a job repairing amplifiers and special effects devices while attending Onondaga Community College in Syracuse, New York, where he majored in electrical engineering.
Snow’s career then progressed to larger companies, where he engaged in more sophisticated high fidelity repair and installations. Gary explained, “I was sent to KLH, McIntosh Laboratories, and the Allen Organ Company for further technical training. In 1971, I was offered employment at Theatre Sound Inc. in New Haven, Connecticut, where I expanded into electronic circuit design, and large system design and installation.”
After some encouragement by friends, he produced a "for sale" product in 1974. Snow chose the name "Audioarts" for his nascent company.
Snow is the recipient of three Industry Innovator awards announced by trade publications in 2017.
History
Wheatstone Corporation was founded as Audioarts Engineering in 1974. and was incorporated under its current name in 1981. Originally founded in Bethany, Connecticut, the company moved twice, first to Syracuse, New York in 1986, then to its present location just outside New Bern, North Carolina in 1998.
The company's first product was a simple disco mixer designed by the founder. In the years that followed, Audioarts designed and sold outboard equipment for the recording industry, including one of the earliest parametric equalizers. In 1976 its first console, the Audioarts 2000, was introduced.
In 1981, working under the internal project name "Wheatstone," Audioarts developed a very full-featured sound reinforcement console. Partly due to the success of this console, the company subsequently incorporated as Wheatstone Corporation.
Brands
In addition to Wheatstone, the corporation also markets products under the following brand names:
Audioarts Engineering is Wheatstone's brand of standalone analog radio consoles. Audioarts was the original name of the corporation.
Pacific Research & Engineering (PR&E) is a brand of digital audio consoles for radio. The brand was acquired in February 2017 from GatesAir, and the brand has been previously marketed by Harris Corporation.
VoxPro is Wheatstone's digital audio recording, playout, and editing system. The brand was acquired in 2015.
Notable Products
WheatNet-IP is an Audio over IP (AoIP) network with applications in broadcast radio, television, and other applications. It provides routing and distribution of audio and logic.
VoxPro is a widely used digital recording and editing system optimized for live radio use. It allows simple and rapid editing of telephone calls, interviews, and other content.
Wheatstone Processing is a line of processing equipment designed to optimize the on-air sound of broadcast and streaming radio. Wheatstone also manufactures equipment for processing of individual microphones and external feeds.
Networked Control Surfaces include consoles connected to the audio network via Ethernet. Wheatstone markets a range of these for both radio and television audio use.
References
External links
Wheatstone Corporation Web Site
Companies based in North Carolina
Broadcast engineering
Manufacturing companies established in 1973
Manufacturers of professional audio equipment
Audio equipment manufacturers of the United States | Wheatstone Corporation | [
"Engineering"
] | 742 | [
"Broadcast engineering",
"Electronic engineering"
] |
59,372,754 | https://en.wikipedia.org/wiki/Charles%20Joseph%20Lambert%20%28engineer%29 | Charles Joseph Lambert, also known as Lambert Bey (Valenciennes, May 2, 1804 - Paris, February 13, 1864) was a French explorer and engineer.
Biography
Lambert was a student of the École polytechnique (1822) and graduated as a mining engineer (1824). Around the year 1829, Lambert met "father" Barthélemy Prosper Enfantin, Michel Chevalier, and Fournel who were trying to propagate the doctrine of Saint-Simonism.
The young engineer became one of their favorite disciples, and abandoned his position to participate in the new religion. Lambert took an active part in the teachings of rue Monsigny, collaborating with the newspaper Le Globe and during the split that occurred in the Saint-Simonian family, he chose to side with Enfantin.
In 1832, Lambert was not included in the lawsuits against the Saint-Simonians. From his refuge at Ménilmontant, he appeared as trial counsel for one of the accused and produced an incisive and mocking speech which elicited a number of observations from the presiding judge.
Sometime afterward (1833), Lambert left for Egypt, and at first taught mathematics in Cairo but soon caught the attention of the Egyptian vice-roy, Muhammad Ali, who gave Lambert several missions:
Lambert created the ( l'École des mines) Mining School which he directed from 1836 to 1840, and then the Bulaq École polytechnique that he directed from 1840 to 1849. Lambert made it the flagship of the educational system organized by Muhammad Ali. Through the network of professors he built up from Egyptians sent to Paris, he was able to train excellent engineers who were considered "civilized" in the term of the day - that is to say, believing in the efficiency of technical progress as a factor of economic development and social progress. A member of the Higher Council for Education, Lambert participated in the development of all reforms of the school system in close liaison with Minister Ethem Bey.
Lambert also provided technical expertise for many projects. The record he created in 1849 of the work he conducted and to which he lent assistance during the reign of Muhammad Ali is eloquent: the Nile Barrage, railroads, irrigation, mines, topography and maps, public works, school programs and inspections, an observatory, gunpowder and saltpeter, paper factories, roads, bridges, causeways, and waster distribution in Cairo.
The Suez Canal
During his time in Egypt, Lambert attentively studied the work of French engineer, Jacques-Marie Le Père, who at the end of the 18th century proposed a canal to traverse the Suez Isthmus. Lambert initiated a feasibility study and 3 drilling projects for the Suez Canal and he drew the public's attention to this project. These results of these three projects were sent to Louis Maurice Adolphe Linant de Bellefonds by Enfantin. Linant worked together with Eugène Mougel on the project that was later realized by Ferdinand de Lesseps.
Lambert's services in Egypt were rewarded with the title of Bey in 1847.
Later life
In 1851, Lambert settled in Paris and devoted his leisure to questions of philosophy: he published a very curious study about the Trinity which was a great success when it appeared in La Revue philosophique et religieuse.
Lambert died in 1864 and was buried at the Montparnasse Cemetery.
Awards
Knight of the Legion of Honor, June 9, 1843
Bibliography
Alfred Mézières, Lettres, sciences, arts: Encyclopédie universelle du XXe, 1908, p. 56
Numa Broc, Dictionnaire des Explorateurs français du XIXe siècle, T.1, Afrique, CTHS, 1988, pp. 185–186
François Angelier, Dictionnaire des Voyageurs et Explorateurs occidentaux, Pygmalion, 2011, p. 414
References
External links
Photographs
Notice in the Maitron
19th-century French explorers
19th-century French engineers
1804 births
People from Valenciennes
1864 deaths
École Polytechnique
Mining engineers
Saint-Simonists
Recipients of the Legion of Honour
Suez Canal | Charles Joseph Lambert (engineer) | [
"Engineering"
] | 844 | [
"Mining engineering",
"Mining engineers"
] |
59,376,303 | https://en.wikipedia.org/wiki/Barbara%20Albert%20%28chemist%29 | Barbara Ruth Albert (born 9 December 1966) is a German chemist and rector of the University of Duisburg-Essen. She was Professor of Solid State Chemistry at the Eduard-Zintl-Institute for Inorganic and Physical Chemistry of the Technische Universität Darmstadt. From 2012 to 2013 she was the president of the German Chemical Society.
Her research focuses on the synthesis of borides, borates and hydro borates, and solids with interesting physical properties.
Life
Albert studied Chemistry at the University of Bonn from 1985 to 1990. She worked on her dissertation in the group of until 1995. With the help of the Feodor Lynen Fellowship of the Alexander von Humboldt Foundation, she worked as a postdoctoral fellow at the Materials Research Laboratory of the University of California, Santa Barbara in the group of Anthony Cheetham. In 2000 she habilitated at the University of Bonn, where she became a Privatdozent in 2001. In the same year she became a professor at the University of Hamburg, where she was also Managing Director of the Institute for Inorganic and Applied Chemistry from 2003 to 2005. From 2005 to 2022 she was a professor at the Technische Universität Darmstadt. From 2012 to 2013 she was the president of the German Chemical Society. She has been a member of the supervisory board of Evonik Industries since 2014 and of the supervisory board of the Schunk Group since 2016. Since April 2022, she is rector of the University of Duisburg-Essen.
Awards
Bennigsen-Foerder Prize in 1997
Prize of the Working Group of German University Professors of Chemistry (ADUC) in 2000
Member of the Berlin-Brandenburg Academy of Sciences since 2016
References
External links
CV at Technische Universität Darmstadt
Living people
1966 births
20th-century German chemists
German women chemists
21st-century German chemists
University of Bonn alumni
Academic staff of Technische Universität Darmstadt
Society of German Chemists
Academic staff of the University of Hamburg
Academic staff of the University of Duisburg-Essen
21st-century German women scientists
Solid state chemists
Presidents of the German Chemical Society | Barbara Albert (chemist) | [
"Chemistry"
] | 435 | [
"Solid state chemists",
"Society of German Chemists"
] |
59,376,743 | https://en.wikipedia.org/wiki/Motifs%20targeted%20by%20APC/C | The anaphase- promoting complex or cyclosome (APC/C) is a highly specific ubiquitin protein ligase responsible for triggering events of late mitosis. In early mitosis, Cdc20 levels rise and APC/C binds to form active APC/CCdc20. This then leads to the destruction of mitotic cyclins, securin, and other proteins to trigger chromosome separation in anaphase. In early anaphase, Cdk1 is inactivated, leading to the activation of Cdh1, the other activator subunit of APC/C. This then triggers the degradation of Cdc20 and leads to the activation of APC/CCdh1 through G1 to suppress S- phase cyclin-Cdk activity. At the end of G1, APC/CCdh1 is inactivated and S- phase and mitotic cyclins gets reaccumulate as the cell progresses to S phase.
APC/C finds its substrates via short, linear sequence motifs or degrons found in its substrates. These degrons can be split into three major groups: destruction boxes, KEN boxes, and ABBA motifs. Binding pockets on the surface of activator subunits of Cdc20 or Cdh1 interact with the degrons on the substrates to target them for ubiquitination and degradation to trigger specific events in the cell cycle.
Degrons targeted by APC/C
The APC/C is a binding platform that associates with an activator subunit (Cdc20 or Cdh1) which has binding pockets on its surface to interact with degrons on the substrate. The three main degrons that the APC/C interacts with are destruction box (also known as D box), the KEN box, and the ABBA motif. Most APC targets contain the D and the KEN box. These degrons are typically located in largely unstructured regions of the substrates.
Destruction Box (D Box)
The D box is a sequence motif found in many targets of the APC with the consensus RxxLxxxxN amino acid sequence. R is arginine, X is any amino acid, L is leucine, and N is asparagine. This binding pocket involves the activator WD40 domain, which is located in the C- terminal half of the APC/C activator subunit, and a site on the Apc10/ Doc1 subunit of the APC/C. RxxL motifs on target substrates contain an acidic patch and an aliphatic (non- aromatic carbon chain) pocket. There is a hydrogen bond between the acidic position on the D box and an arginine amino acid on the activator surface.
KEN Box
The KEN box is a sequence motif targeted by the APC with the consensus KENxxxN (K is lysine and E is glutamate). This motif binds on the top surface of the WD40 domain of the APC activator subunit (Cdh1 or Cdc20) and forms an underwound helix with a tight turn in the pocket, which creates charged residues of the consensus to contact the binding pocket on the activator surface.
One interesting example is the KEN box located on the activating subunit of the APC/C Cdc20, which is preferentially recognized by Cdh1. This ensures degradation of Cdc20 following Cdh1 dephosphorylation and activation at the exit of mitosis.
ABBA motif
The ABBA motif recognizes peptides with a consensus [ILVF]x[ILMVP][FHY]x[DE]. Only a small number of substrates have been shown to have this motif. This motif targets S phase cyclins like Clb5 and Cyclin A2, which are the first substrates that get degraded in mitosis.
Multiple APC/C motifs on substrates
Substrates can have more than one motif and doing so makes them particularly good substrates for the APC/C to target. For example, S- phase cyclin5 (Clb5), a protein in budding yeast, contains the Ken Box, D Box, ABBA motif, and a Cks1 co-factor to be targeted in pre-metaphase for degron cooperativity. Cyclin A2, a protein in humans, contains the Ken Box, ABBA motif, D Box, and a Cks1 co-factor to be targeted during prometaphase.
References
Proteins | Motifs targeted by APC/C | [
"Chemistry"
] | 941 | [
"Biomolecules by chemical classification",
"Proteins",
"Molecular biology"
] |
59,376,843 | https://en.wikipedia.org/wiki/Alta%20Devices | Alta Devices was a US-based specialty gallium arsenide (GaAs) PV manufacturer, which claimed to have achieved a solar cell conversion efficiency record of 29.1%, as certified by Germany's Fraunhofer ISE CalLab.
The company has ceased operations.
History
Alta Devices was founded in 2007 by Eli Yablonovitch and Harry Atwater and manufactured solar photovoltaic applications for mobile devices that enable the conversion of light into electricity. The firm was acquired by Hanergy Group, a privately held Chinese multinational renewable energy company, in 2013
The firm's technology was significant for unmanned aerial vehicles (UAVs), solar cars, and other electric vehicles.' NASA has been testing its solar technology for the International Space Station. The firm had been working with Audi on 'solar roofs' for their automobiles. Audi working with Alta Devices on cars with ‘solar roofs’ Opics.org. 24 Aug 2017
The firm broke efficiency records for single-junction solar cells and solar modules. In 2016, Alta Devices broke the world record conversion efficiency for dual-junction solar cell using InGaP/GaAs tandem structure. The world record was certified by National Renewable Energy Laboratory. This is the second time Alta Devices broke world record efficiency. The first time was 30.8% in 2013.
In 2019, the company ceased operations.
Awards
2018 - Finalist in the 2019 Prism Awards for Photonics Innovation, determined by SPIE and Photonics Media.
See also
Solar cell efficiency
Timeline of solar cells
References
Photovoltaics manufacturers
Renewable energy companies of the United States | Alta Devices | [
"Engineering"
] | 320 | [
"Photovoltaics manufacturers",
"Engineering companies"
] |
59,378,438 | https://en.wikipedia.org/wiki/Christine%20Loscher | Christine E. Loscher is a Professor of Biotechnology and Associate Dean for Research at Dublin City University. Loscher is director of the Health Technologies Research and Enterprise Hub, and she works on bioactive molecules for autoimmune diseases.
Early life and education
During her undergraduate studies at the Dublin Institute of Technology, Loscher worked with Cliona O’Farrelly at St. Vincent's University Hospital. Loscher earned her PhD at the National University of Ireland in 2000. Following her graduate studies, Loscher joined Trinity College Dublin as a postdoctoral researcher. She worked with Kingston Mills on how vaccines can trigger fevers. In 2003 she was appointed to the St. James's Hospital Institute of Molecular Medicine.
Career
Loscher joined Dublin City University in 2005. She established the Immunomodulation Research Group with Helen Roche. She also directs the Nano-Bioanalytical Research Facility. She looks at how modulating the immune response can improve health, developing new anti-inflammatory compounds for the pharmaceutical and food industry. She investigates bioactive molecules in marine mash. Whilst the immune system may be best known for fighting disease, it is sometimes triggered into chronic inflammation. She has described her work to the Irish Independent.
She served as Principal Investigator for the research consortium Food for Health Ireland, an organisation that partners academics with Irish dairy and ingredient companies. She has worked with Teagasc to identify ingredients that can help lactose intolerance infants. She discovered how the immune system responds to Clostridioides difficile - outer proteins trigger immune responses. Loscher serves on the Irish Society of Immunology.
Public engagement
Loscher runs ResearchFest, a strand of InspireFest, where researchers give short talks about their work. In 2016 she announced that Dublin City University would name half of its buildings after inspirational women. She contributed to the Royal Society of Chemistry Innate Immunology Summit. She was selected by Silicon Republic as one of the Women Invent Tomorrow in 204 and Top 100 Women in Science in 2016. She delivered a TED Talk on the Future of Food. In 2018 she was selected by Silicon Republic as one of the top 22 scientists to follow.
References
Year of birth missing (living people)
Living people
Women immunologists
Irish immunologists
Irish women scientists
Women science writers
Academics of Dublin City University
Alumni of Trinity College Dublin | Christine Loscher | [
"Technology"
] | 474 | [
"Women science writers",
"Women in science and technology"
] |
59,383,794 | https://en.wikipedia.org/wiki/Nanoparticle%20drug%20delivery | Nanoparticle drug delivery systems are engineered technologies that use nanoparticles for the targeted delivery and controlled release of therapeutic agents. The modern form of a drug delivery system should minimize side-effects and reduce both dosage and dosage frequency. Recently, nanoparticles have aroused attention due to their potential application for effective drug delivery.
Nanomaterials exhibit different chemical and physical properties or biological effects compared to larger-scale counterparts that can be beneficial for drug delivery systems. Some important advantages of nanoparticles are their high surface-area-to-volume ratio, chemical and geometric tunability, and their ability to interact with biomolecules to facilitate uptake across the cell membrane. The large surface area also has a large affinity for drugs and small molecules, like ligands or antibodies, for targeting and controlled release purposes.
Nanoparticles refer to a large family of materials both organic and inorganic. Each material has uniquely tunable properties and thus can be selectively designed for specific applications. Despite the many advantages of nanoparticles, there are also many challenges, including but not exclusive to: nanotoxicity, biodistribution and accumulation, and the clearance of nanoparticles by human body.
The National Institute of Biomedical Imaging and Bioengineering has issued the following prospects for future research in nanoparticle drug delivery systems:
crossing the blood-brain barrier (BBB) in brain diseases and disorders;
enhancing targeted intracellular delivery to ensure the treatments reach the correct structures inside cells;
combining diagnosis and treatment.
The development of new drug systems is time-consuming; it takes approximately seven years to complete fundamental research and development before advancing to preclinical animal studies.
Characterization
Nanoparticle drug delivery focuses on maximizing drug efficacy and minimizing cytotoxicity. Fine-tuning nanoparticle properties for effective drug delivery involves addressing the following factors.
The surface-area-to-volume ratio of nanoparticles can be altered to allow for more ligand binding to the surface. Increasing ligand binding efficiency can decrease dosage and minimize nanoparticle toxicity. Minimizing dosage or dosage frequency also lowers the mass of nanoparticle per mass of drug, thus achieving greater efficiency.
Surface functionalization of nanoparticles is another important design aspect and is often accomplished by bioconjugation or passive adsorption of molecules onto the nanoparticle surface. By functionalizing nanoparticle surfaces with ligands that enhance drug binding, suppress immune response, or provide targeting/controlled release capabilities, both a greater efficacy and lower toxicity are achieved. Efficacy is increased as more drug is delivered to the target site, and toxic side effects are lowered by minimizing the total level of drug in the body.
The composition of the nanoparticle can be chosen according to the target environment or desired effect. For example, liposome-based nanoparticles can be biologically degraded after delivery, thus minimizing the risk of accumulation and toxicity after the therapeutic cargo has been released.
Metal nanoparticles, such as gold nanoparticles, have optical qualities(also described in nanomaterials) that allow for less invasive imaging techniques. Furthermore, the photothermal response of nanoparticles to optical stimulation can be directly utilized for tumor therapy.
Platforms
Current nanoparticle drug delivery systems can be cataloged based on their platform composition into several groups: polymeric nanoparticles, inorganic nanoparticles, viral nanoparticles, lipid-based nanoparticles, and nanoparticle albumin-bound (nab) technology. Each family has its unique characteristics.
Polymeric nanoparticles
Polymeric nanoparticles are synthetic polymers with a size ranging from 10 to 100 nm. Common synthetic polymeric nanoparticles include polyacrylamide, polyacrylate, and chitosan. Drug molecules can be incorporated either during or after polymerization. Depending on the polymerization chemistry, the drug can be covalently bonded, encapsulated in a hydrophobic core, or conjugated electrostatically. Common synthetic strategies for polymeric nanoparticles include microfluidic approaches, electrodropping, high pressure homogenization, and emulsion-based interfacial polymerization.
Polymer biodegradability is an important aspect to consider when choosing the appropriate nanoparticle chemistry. Nanocarriers composed of biodegradable polymers undergo hydrolysis in the body, producing biocompatible small molecules such as lactic acid and glycolic acid.
Polymeric nanoparticles can be created via self assembly or other methods such as particle replication in nonwetting templates (PRINT) which allows customization of composition, size, and shape of the nanoparticle using tiny molds.
Dendrimers
Dendrimers are unique hyper-branched synthetic polymers with monodispersed size, well-defined structure, and a highly functionalized terminal surface. They are typically composed of synthetic or natural amino acid, nucleic acids, and carbohydrates. Therapeutics can be loaded with relative ease onto the interior of the dendrimers or the terminal surface of the branches via electrostatic interaction, hydrophobic interactions, hydrogen bonds, chemical linkages, or covalent conjugation. Drug-dendrimer conjugation can elongate the half-life of drugs. Currently, dendrimer use in biological systems is limited due to dendrimer toxicity and limitations in their synthesis methods. Dendrimers are also confined within a narrow size range (<15 nm) and current synthesis methods are subject to low yield. The surface groups will reach the de Gennes dense packing limit at high generation level, which seals the interior from the bulk solution – this can be useful for encapsulation of hydrophobic, poorly soluble drug molecules. The seal can be tuned by intramolecular interactions between adjacent surface groups, which can be varied by the condition of the solution, such as pH, polarity, and temperature, a property which can be utilized to tailor encapsulation and controlled release properties.
Inorganic Nanoparticles and Nanocrystals
Inorganic nanoparticles have emerged as highly valuable functional building blocks for drug delivery systems due to their well-defined and highly tunable properties such as size, shape, and surface functionalization. Inorganic nanoparticles have been largely adopted to biological and medical applications ranging from imaging and diagnoses to drug delivery. Inorganic nanoparticles are usually composed of inert metals such as gold and titanium that form nanospheres, however, iron oxide nanoparticles have also become an option.
Quantum dots (QDs), or inorganic semiconductor nanocrystals, have also emerged as valuable tools in the field of bionanotechnology because of their unique size-dependent optical properties and versatile surface chemistry. Their diameters (2 - 10 nm) are on the order of the exciton Bohr radius, resulting in quantum confinement effects analogous to the "particle-in-a-box" model. As a result, optical and electronic properties of quantum dots vary with their size: nanocrystals of larger sizes will emit lower energy light upon fluorescence excitation.
Surface engineering of QDs is crucial for creating nanoparticle–biomolecule hybrids capable of participating in biological processes. Manipulation of nanocrystal core composition, size, and structure changes QD photo-physical properties Designing coating materials which encapsulate the QD core in an organic shell make nanocrystals biocompatible, and QDs can be further decorated with biomolecules to enable more specific interaction with biological targets. The design of inorganic nanocrystal core coupled with biologically compatible organic shell and surface ligands can combine useful properties of both materials, i.e. optical properties of the QDs and biological functions of ligands attached.
Toxicity
While application of inorganic nanoparticles in bionanotechnology shows encouraging advancements from a materials science perspective, the use of such materials in vivo is limited by issues related with toxicity, biodistribution and bioaccumulation. Because metal inorganic nanoparticle systems degrade into their constituent metal atoms, challenges may arise from the interactions of these materials with biosystems, and a considerable amount of the particles may remain in the body after treatment, leading to buildup of metal particles potentially resulting in toxicity.
Recently, however, some studies have shown that certain nanoparticle environmental toxicity effects aren't apparent until nanoparticles undergo transformations to release free metal ions. Under aerobic and anaerobic conditions, it was found that copper, silver, and titanium nanoparticles released low or insignificant levels of metal ions. This is evidence that copper, silver, and titanium NP are slow to release metal ions, and may therefore appear at low levels in the environment. Additionally, nanoshell coatings significantly protect against degradation in the cellular environment and also reduce QDs toxicity by reducing metal ion leakage from the core.
Organic Nanocrystals
Organic nanocrystals consist of pure drugs and surface active agents required for stabilization. They are defined as carrier-free submicron colloidal drug delivery systems with a mean particle size in the nanometer range. The primary importance of the formulation of drugs into nanocrystals is the increase in particle surface area in contact with the dissolution medium, therefore increasing bioavailability. A number of drug products formulated in this way are on the market.
Solubility
One of the issues faced by drug delivery is the solubility of the drug in the body; around
40% of newly detected chemicals found in drug discovery are poorly soluble in water. This low solubility affects the bioavailability of the drug, meaning the rate at which the drug reaches the circulatory system and thus the target site. Low bioavailability is most commonly seen in oral administration, which is the preferred choice for drug administration due to its convenience, low costs, and good patient practice. A measure to improve poor bioavailability is to inject the drugs in a solvent mixture with a solubilizing agent. However, results show this solution is ineffective, with the solubilizing agent demonstrating side-effects and/or toxicity.
Nanocrystals used for drug delivery can increase saturation solubility and dispersion velocity. Generally, saturation solubility is thought to be a function of temperature, but it is also based on other factors, such as crystalline structure and particle size, in regards to nanocrystals. The Ostwald-Freundlich equation below shows this relationship:
Where Cs is the saturation solubility of the nanocrystal, C𝛼 is the solubility of the drug at a non-nano scale, σ is the interfacial tension of the substance, V is the molar volume of the particle, R is the gas constant, T is the absolute temperature, 𝜌 is the density of the solid, and r is the radius. The advantage of nanocrystals is that they can improve oral adsorption, bioavailability, action onset and reduces intersubject variability.
Consequently, nanocrystals are now being produced and are on the market for a variety of purposes ranging from antidepressants to appetite stimulants. Nanocrystals can be produced using two different ways: the top-down method or the bottom-up method. Bottom-up technologies are also known as nanoprecipitation. This technique involves dissolving a drug in a suitable solvent and then precipitating it with a non-solvent. On the other hand, top-down technologies use force to reduce the size of a particle to nanometers, usually done by milling a drug. Top-down methods are preferred when working with poorly soluble drugs.
Stability
A disadvantage of using nanocrystals for drug delivery is nanocrystal stability. Instability problems of nanocrystalline structures derive from thermodynamic processes such as particle aggregation, amorphization, and bulk crystallization. Particles at the nanoscopic scale feature a relative excess of Gibbs free energy, due to their higher surface area to volume ratio. To reduce this excess energy, it is generally favorable for aggregation to occur. Thus, individual nanocrystals are relatively unstable by themselves and will generally aggregate. This is particularly problematic in top-down production of nanocrystals. Methods such as high-pressure homogenization and bead milling, tend to increase instabilities by increasing surface areas; to compensate, or as a response to high pressure, individual particles may aggregate or turn amorphous in structure. Such methods can also lead to the reprecipitation of the drug by surpassing the solubility beyond the saturation point (Ostwald ripening).
One method to overcome aggregation and retain or increase nanocrystal stability is by use of stabilizer molecules. These molecules, which interact with the surface of the nanocrystals and prevent aggregation via ionic repulsion or steric barriers between the individual nanocrystals, include surfactants and are generally useful for stabilizing suspensions of nanocrystals. Concentrations of surfactants that are too high, however, may inhibit nanocrystal stability and enhance crystal growth or aggregation. It has been shown that certain surfactants, upon reaching a critical concentration, begin to self-assemble into micelles, which then compete with nanocrystal surfaces for other surfactant molecules. With fewer surface molecules interacting with the nanocrystal surface, crystal growth and aggregation is reported to occur at increased amounts. Use of surfactant at optimal concentrations reportedly allows for higher stability, larger drug capacity as a carrier, and sustained drug release. In a study using PEG as a stabilizer was found that nanocrystals treated with PEG enhanced accumulation at tumor sites and had greater blood circulation, than those not treated with PEG.
Amorphization can occur in top-down methods of production. With different intramolecular arrangements, amorphization of nanocrystals leads to different thermodynamic and kinetic properties that affect drug delivery and kinetics. Transition to amorphous structures is reported to occur through production practices such as spray drying, lyophilization, and mechanical mechanisms, such as milling. This amorphization has been reportedly observed with or without the presence of stabilizer in a dry milling process. Using a wet milling process with surfactant, however significantly reduced amorphization, suggesting that solvent, in this case water, and surfactant could inhibit amorphization for some top-down production methods that otherwise reportedly facilitate amorphization.
Liposome delivery
Liposomes are spherical vesicles composed of synthetic or natural phospholipids that self-assemble in aqueous solution in sizes ranging from tens of nanometers to micrometers. The resulting vesicle, which has an aqueous core surrounded by a hydrophobic membrane, can be loaded with a wide variety of hydrophobic or hydrophilic molecules for therapeutic purposes.
Liposomes are typically synthesized with naturally occurring phospholipids, mainly phosphatidylcholine. Cholesterol is often included in the formulation to adjust the rigidity of the membrane and to increase stability. The molecular cargo is loaded through liposome formation in aqueous solution, solvent exchange mechanisms, or pH gradients methods. Various molecules can also be chemically conjugated to the surface of the liposome to alter recognition properties. One typical modification is conjugating polyethyleneglycol (PEG) to the vesicle surface. The hydrophilic polymer prevents recognition by macrophages and decreases clearance. The size, surface charge, and bilayer fluidity also alter liposome delivery kinetics.
Liposomes diffuse from the bloodstream into the interstitial space near the target site. As the cell membrane itself is composed of phospholipids, liposomes can directly fuse with the membrane and release the cargo into the cytosol, or may enter the cell through phagocytosis or other active transport pathways.
Liposomal delivery has various advantages. Liposomes increase the solubility, stability, and uptake of drug molecules. Peptides, polymers, and other molecules can be conjugated to the surface of a liposome for targeted delivery. Conjugating various ligands can facilitate binding to target cells based on the receptor-ligand interaction. Altering vesicle size and surface chemistry can also be tuned to increase circulation time.
Various FDA-approved liposomal drugs are in clinical use in the US. The anthracycline drug doxorubicin is delivered with phospholipid-cholesterol liposomes to treat AIDS-related Kaposi sarcoma and multiple myeloma with high efficacy and low toxicity. Many others are undergoing clinical trials, and liposomal drug delivery remains an active field of research today, with potential applications including nucleic acid therapy, brain targeting, and tumor therapy.
Viral vectors, viral-like particles, and biological nanocarriers
Viruses can be used to deliver genes for genetic engineering or gene therapy. Commonly used viruses include adenoviruses, retroviruses, and various bacteriophages. The surface of the viral particle can also be modified with ligands to increase targeting capabilities. While viral vectors can be used to great efficacy, one concern is that may cause off-target effects due to its natural tropism. This usually requires replacing the proteins causing virus-cell interactions with chimeric proteins.
In addition to using viruses, drug molecules can also be encapsulated in protein particles derived from the viral capsid, or virus-like particles (VLPs). VLPs are easier to manufacture than viruses, and their structural uniformity allows VLPs to be produced precisely in large amounts. VLPs also have easy-to-modify surfaces, allowing the possibility for targeted delivery. There are various methods of packaging the molecule into the capsid; most take advantage of the capsid's ability to self-assemble. One strategy is to alter the pH gradient outside the capsid to create pores on the capsid surface and trap the desired molecule. Other methods use aggregators such as leucine zippers or polymer-DNA amphiphiles to induce capsid formation and capture drug molecules. It is also possible to chemically conjugate of drugs directly onto the reactive sites on the capsid surface, often involving the formation of amide bonds.
After being introduced to the organism, VLPs often have broad tissue distribution, rapid clearance, and are generally non-toxic. It may, however, like viruses, invoke an immune response, so immune-masking agents may be necessary.
Nanoparticle Albumin-bound (nab) Technology
Nanoparticle albumin-bound technology utilizes the protein albumin as a carrier for hydrophobic chemotherapy drugs through noncovalent binding. Because albumin is already a natural carrier of hydrophobic particles and is able to transcytose molecules bound to itself, albumin composed nanoparticles have become an effective strategy for the treatment of many diseases in clinical research.
Delivery and release mechanisms
An ideal drug delivery system should have effective targeting and controlled release. The two main targeting strategies are passive targeting and active targeting. Passive targeting depends on the fact that tumors have abnormally structured blood vessels that favor accumulation of relatively large macromolecules and nanoparticles. This so-called enhanced permeability and retention effect (EPR) allows the drug-carrier be transported specifically to the tumor cells. Active targeting is, as the name suggests, much more specific and is achieved by taking advantage of receptor-ligand interactions at the surface of the cell membrane. Controlled drug release systems can be achieved through several methods. Rate-programmed drug delivery systems are tuned to the diffusivity of active agents across the membrane. Another delivery-release mechanism is activation-modulated drug delivery, where the release is triggered by environmental stimuli. The stimuli can be external, such as the introduction of a chemical activators or activation by light or electromagnetic fields, or biological - such as pH, temperature, and osmotic pressure which can vary widely throughout the body.
Polymeric nanoparticles
For polymeric nanoparticles, the induction of stimuli-responsiveness has usually relied heavily upon well-known polymers that possess an inherent stimuli-responsiveness. Certain polymers that can undergo reversible phase transitions due to changes in temperature or pH have aroused interest.
Arguably the most utilized polymer for activation-modulated delivery is the thermo-responsive polymer poly(N-isopropylacrylamide). It is readily soluble in water at room temperature but precipitates reversibly from when the temperature is raised above its lower critical solution temperature (LCST), changing from an extended chain conformation to a collapsed chain. This feature presents a way to change the hydrophilicity of a polymer via temperature.
Efforts also focus on dual stimuli-responsive drug delivery systems, which can be harnessed to control the release of the encapsulated drug. For example, the triblock copolymer of poly(ethylene glycol)-b-poly(3-aminopropyl-methacrylamide)-b-poly(N-isopropylacrylamide) (PEG-b-PAPMA-b-PNIPAm) can self-assemble to form micelles, possessing a core–shell–corona architecture above the lower critical solution temperature. It is also pH responsive. Therefore, drug release can be tuned by changing either temperature or pH conditions.
Inorganic nanoparticles
Drug delivery strategies of inorganic nanoparticles are dependent on material properties. The active targeting of inorganic nanoparticle drug carriers is often achieved by surface functionalization with specific ligands of nanoparticles. For example, the inorganic multifunctional nanovehicle (5-FU/Fe3O4/αZrP@CHI-FA-R6G) is able to accomplish tumor optical imaging and therapy simultaneously. It can be directed to the location of cancer cells with sustained release behavior.
Studies have also been done on gold nanoparticle responses to local near-infrared (NIR) light as a stimuli for drug release. In one study, gold nanoparticles functionalized with double-stranded DNA encapsulated with drug molecules, were irradiated with NIR light. The particles generated heat and denatured the double-stranded DNA, which triggered the release of drugs at the target site.
Studies also suggest that a porous structure is beneficial to attain a sustained or pulsatile release. Porous inorganic materials demonstrate high mechanical and chemical stability within a range of physiological conditions. The well-defined surface properties, such as high pore volume, narrow pore diameter distribution, and high surface area allow the entrapment of drugs, proteins and other biogenic molecules with predictable and reproducible release patterns.
Toxicity
Some of the same properties that make nanoparticles efficient drug carriers also contribute to their toxicity. For example, gold nanoparticles are known to interact with proteins through surface adsorption, forming a protein corona, which can be utilized for cargo loading and immune shielding. However, this protein-adsorption property can also disrupt normal protein function that is essential for homeostasis, especially when the protein contains exposed sulfur groups. The photothermal effect, which can be induced to kill tumor cells, may also create reactive oxygen species that impose oxidative stress on surrounding healthy cells. Gold nanoparticles of sizes below 4-5 nm fit in DNA grooves which can interfere with transcription, gene regulation, replication, and other processes that rely on DNA-protein binding. Lack of biodegradability for some nanoparticle chemistries can lead to accumulation in certain tissues, thus interfering with a wide range of biological processes. Currently, there is no regulatory framework in the United States for testing nanoparticles for their general impact on health and on the environment.
References
Nanoparticles
Drug delivery devices
Nanomedicine | Nanoparticle drug delivery | [
"Chemistry",
"Materials_science"
] | 5,021 | [
"Nanomedicine",
"Pharmacology",
"Drug delivery devices",
"Nanotechnology"
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59,384,115 | https://en.wikipedia.org/wiki/EEG%20analysis | EEG analysis is exploiting mathematical signal analysis methods and computer technology to extract information from electroencephalography (EEG) signals. The targets of EEG analysis are to help researchers gain a better understanding of the brain; assist physicians in diagnosis and treatment choices; and to boost brain-computer interface (BCI) technology. There are many ways to roughly categorize EEG analysis methods. If a mathematical model is exploited to fit the sampled EEG signals, the method can be categorized as parametric, otherwise, it is a non-parametric method. Traditionally, most EEG analysis methods fall into four categories: time domain, frequency domain, time-frequency domain, and nonlinear methods. There are also later methods including deep neural networks (DNNs).
Although it is extremely important for researchers to choose the appropriate EEG analysis methods according to their research objectives and the results they want to obtain, the finalized studies provide reference for future research, help solve existing problems and prepare the ground for future studies.
Methods
Frequency domain methods
Frequency domain analysis, also known as spectral analysis, is the most conventional yet one of the most powerful and standard methods for EEG analysis. It gives insight into information contained in the frequency domain of EEG waveforms by adopting statistical and Fourier Transform methods. Among all the spectral methods, power spectral analysis is the most commonly used, since the power spectrum reflects the 'frequency content' of the signal or the distribution of signal power over frequency. This technique can be used to investigate the energy changes of different frequency components in EEG signals during EEG analysis. It is appropriate for use in the study of neurological diseases and brain science, as these conditions can cause EEG energy changes during changes in state, such as changes in sleep phase, seizures, and emotional states.
Time domain methods
There are two important methods for time domain EEG analysis: Linear Prediction and Component Analysis. Generally, Linear Prediction gives the estimated value equal to a linear combination of the past output value with the present and past input value. And Component Analysis is an unsupervised method in which the data set is mapped to a feature set. Notably, the parameters in time domain methods are entirely based on time, but they can also be extracted from statistical moments of the power spectrum. As a result, time domain method builds a bridge between physical time interpretation and conventional spectral analysis. Besides, time domain methods offer a way to on-line measurement of basic signal properties by means of a time-based calculation, which requires less complex equipment compared to conventional frequency analysis.
Time-frequency domain methods
Time-frequency analysis is typically performed using the Wavelet Transform (WT), Empirical Mode Decomposition (EMD), Wigner-Ville Distribution (WVD), and Short-time Fourier Transform (STFT).
WT, a typical time-frequency domain method, can extract and represent properties from transient biological signals. Specifically, through wavelet decomposition of the EEG records, transient features can be accurately captured and localized in both time and frequency context. Thus WT is like a mathematical microscope that can analyze different scales of neural rhythms and investigate small-scale oscillations of the brain signals while ignoring the contribution of other scales. Apart from WT, there is another prominent time-frequency method called Hilbert-Huang Transform, which can decompose EEG signals into a set of oscillatory components called Intrinsic Mode Function (IMF) in order to capture instantaneous frequency data.
Nonlinear methods
Many phenomena in nature are nonlinear and non-stationary, and so are EEG signals. This attribute adds more complexity to the interpretation of EEG signals, rendering linear methods (methods mentioned above) limited. Since 1985 when two pioneers in nonlinear EEG analysis, Rapp and Bobloyantz, published their first results, the theory of nonlinear dynamic systems, also called 'chaos theory', has been broadly applied to the field of EEG analysis. To conduct nonlinear EEG analysis, researchers have adopted many useful nonlinear parameters such as Lyapunov Exponent, Correlation Dimension, and entropies like Approximate Entropy and Sample Entropy.
ANN methods
The implementation of Artificial Neural Networks (ANN) is presented for classification of electroencephalogram (EEG) signals. In most cases, EEG data involves a preprocess of wavelet transform before putting into the neural networks. RNN (recurrent neural networks) was once considerably applied in studies of ANN implementations in EEG analysis. Until the boom of deep learning and CNN (Convolutional Neural Networks), CNN method becomes a new favorite in recent studies of EEG analysis employing deep learning. With cropped training for the deep CNN to reach competitive accuracies on the dataset, deep CNN has presented a superior decoding performance. Moreover, the big EEG data, as the input of ANN, calls for the need for safe storage and high computational resources for real-time processing. To address these challenges, a cloud-based deep learning has been proposed and presented for real-time analysis of big EEG data.
Applications
EEG, a non-invasive procedure, is used to record brain activity in cognitive studies, different clinical applications and brain-computer interfaces (BCI). EEG recording is both an easily portable method for different clinical uses and open to applications in various fields as it directly measures collective neural activity.
In terms of cost, EEG recording is considered less expensive than other non-invasive brain signal recording technologies such as functional magnetic resonance imaging (fMRI), magnetoencephalography (MEG), and near-infrared spectroscopy (NIRS).
Clinical
EEG analysis is widely used in brain-disease diagnosis and assessment. In the domain of epileptic seizures, the detection of epileptiform discharges in the EEG is an important component in the diagnosis of epilepsy. Careful analyses of the EEG records can provide valuable insight and improved understanding of the mechanisms causing epileptic disorders. Besides, EEG analysis also helps much with the detection of Alzheimer's disease, tremor, etc.
BCI (Brain-computer Interface)
EEG recordings during right and left motor imagery allow one to establish a new communication channel. Based on real-time EEG analysis with subject-specific spatial patterns, a brain–computer interface (BCI) can be used to develop a simple binary response for the control of a device.
EEG-based BCI approaches, together with advances in machine learning and other technologies such as wireless recording, aim to contribute to the daily lives of people with disabilities and significantly improve their quality of life. Such an EEG-based BCI can help, e.g., patients with amyotrophic lateral sclerosis, with some daily activities.
Analysis tool
Brainstorm is a collaborative, open-source application dedicated to the analysis of brain recordings including MEG, EEG, fNIRS, ECoG, depth electrodes and animal invasive neurophysiology. The objective of Brainstorm is to share a comprehensive set of user-friendly tools with the scientific community using MEG/EEG as an experimental technique. Brainstorm offers rich and intuitive graphic interface for physicians and researchers, which does not require any programming knowledge. Some other relative open source analysis software include FieldTrip, etc.
Others
Combined with facial expressions analysis, EEG analysis offers the function of continuous emotion detection, which can be used to find the emotional traces of videos. Some other applications include EEG-based brain mapping, personalized EEG-based encryptor, EEG-Based image annotation system, etc.
See also
References
Further reading
Electroencephalography
Neurotechnology
Signal processing
Mathematics in medicine | EEG analysis | [
"Mathematics",
"Technology",
"Engineering"
] | 1,568 | [
"Telecommunications engineering",
"Computer engineering",
"Signal processing",
"Applied mathematics",
"Mathematics in medicine"
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42,901,960 | https://en.wikipedia.org/wiki/Pleasant%20Password%20Server | Pleasant Password Server (also known by its new name Keepass Hub) is a proprietary, multi-user enterprise password server that is fully compatible with a modified version of the KeePass Password Safe.
Features
Pleasant Password Server supports the use of secure passwords, allowing system administrators to manage user passwords from a central web interface.
Developed by Pleasant Solutions Inc., product pricing is based upon the number of software users licensed for the product, the length of product support as well as product upgrades.
Standard Edition
The standard server stores user passwords and login information using a secure database that is managed internally by the company. All versions of the software maintain a core feature set, including:
Single Password: user names, passwords and website information are secured by single master password that is unique for each user.
KeePass Compatibility: support for most KeePass plug-ins.
A web client permits user access outside the company intranet, using any operating system.
Multiple Language Extensions: over 40 language translations available for download.
Automatic clipboard erase & random password generator for work teams.
Ability to disable users when they have left the company, freezing further credential access.
Enterprise Edition
The Enterprise Edition includes additional features, primarily:
Active Directory/LDAP Integration: Import, export and synchronization with existing LDAP databases.
Customize or modify access and permissions granted to a user or role.
View access and permissions granted to a user or role.
Logging of when passwords were accessed, with export to .csv file.
Pleasant Solutions Inc. has also developed a password proxy module which prevents credentials from being stored on user devices, shielding enterprise passwords from users.
The password software extends to desktop and mobile environments, and is tested for compatibility with Chrome, Firefox, Internet Explorer, Opera, Android devices, iOS devices as well as other web browsers.
See also
List of password managers
Password manager
Cryptography
Encryption
References
External links
official Keepass Hub website and official Pleasant Password Server website
Pleasant Password Server - Change Log
Password managers
Cryptographic software | Pleasant Password Server | [
"Mathematics"
] | 414 | [
"Cryptographic software",
"Mathematical software"
] |
42,902,934 | https://en.wikipedia.org/wiki/Penicillium%20vanoranjei | Penicillium vanoranjei (orange penicillium) is an orange-colored fungus first described in 2013 from specimens collected in Tunisia. It was named after the Prince of Orange () Willem-Alexander to commemorate his coronation as King of the Netherlands.
Description
Penicillium vanoranjei is distinguished from related species by an unusual bright-orange sclerotia when in colonies; the research team who identified it called the color "astonishing; none of our researchers had ever seen anything like it before." The sclerotia have well-defined, complex internal structure. Conidiophores are monoverticillate (unbranched). The cell walls of fungus have a distinct roughening. It produces an external cell-matrix that might help protect it against dehydration during times of drought. Colonies of P. vanoranjei are slightly raised in the center; mycelia are white near the margins.
Penicillium vanoranjei was identified using a combination of morphological traits and genetic analysis on soil samples taken from Tunisia. It is unknown whether the fungus can be used to make penicillin.
In May 2014, the International Institute for Species Exploration listed P. vanoranjei as one of the "Top 10 News Species" named in 2013.
Taxonomic history
Penicillium vanoranjei and four other similar species – Penicillium maximae, Penicillium amaliae, Penicillium alexiae, and Penicillium arianeae – were set to be named in April 2013. That same month, Prince of Orange () Willem-Alexander was set to become the king of Netherlands. Inspired by the orange colors of P. vanoranjei, Pedro Crous and his colleagues at the CBS-KNAW Fungal Biodiversity Centre decided to "pay a humorous but respectful tribute by naming the new moulds after the new King of the Netherlands and his family." The species were formally described in the journal Persoonia.
The naming attracted attention on social media, and was covered by international media. In the Netherlands, the naming was especially well-covered including TV news stories and radio interviews of the paper's authors. The Penicillium species are not the first to be named after royalty, though. For example, the lily Victoria regia was named after the United Kingdom's Queen Victoria.
References
Fungi described in 2013
vanoranjei
Fungus species | Penicillium vanoranjei | [
"Biology"
] | 502 | [
"Fungi",
"Fungus species"
] |
42,903,555 | https://en.wikipedia.org/wiki/A.J.%20Drexel%20Plasma%20Institute | The Drexel Plasma Institute, in Camden, New Jersey, is the largest university-based plasma research facility in the United States. Led by Drexel University, the members of the scientific team are from University of Illinois at Chicago, Argonne National Laboratory, Pacific Northwest National Laboratory and Kurchatov Institute of Atomic Energy. The primary fields of research are applications in medicine, Environmental Control, energy, and agricultural industries. The institute actively develops and researches specific types of plasma discharges such as gliding arc, dielectric barrier discharge, gliding arc tornado, reverse vortex flow, Pulsed Corona Discharge, and many more.
Applications
Many applications of plasma can be utilized in many industries. As such, its application is often categorized in the context of its research. For example, the dissociation of hydrogen sulfide can be labeled as an environmental application. However, its production of gaseous hydrogen can be more relevant to the energy industry. As such, it is categorized on its researched application, rather than its objective goal.
Medicine
Dr. Gregory Fridman is the laboratory director regarding the application of plasma in the field of medicine. Along with teaching at Drexel University, he creates and finds new applications of plasma in medicine such as blood coagulation.
Environmental control
Energy
Alexander Rabinovich is the laboratory director regarding the application of plasma in the field of energy. Primarily, he studies and researches how plasma can be used in the Energy Systems, Fuel Conversion & Hydrogen Production Division. Some of his research is specialized in conversion of certain gases or the dissociation of others:
"Gliding Arc Plasma-Stimulated Conversion of Pyrogas into Synthesis Gas"
"Low-Temperature Plasma Reforming of Hydrocarbon Fuels Into Hydrogen and Carbon Suboxide for Energy Generation Without CO2 Emission"
"Plasma assisted dissociation of hydrogen sulfide"
Agriculture
References
Plasma physics facilities
Research institutes in New Jersey
Drexel University
Education in Camden, New Jersey
Organizations established in 2002
2002 establishments in New Jersey | A.J. Drexel Plasma Institute | [
"Physics"
] | 400 | [
"Plasma physics facilities",
"Plasma physics"
] |
42,904,501 | https://en.wikipedia.org/wiki/Instrument%20myopia | Instrument myopia is the tendency of a person with normal eyes to focus them too close when looking into an optical instrument at its image. Optical instruments include viewfinders, telescopes, binoculars, and microscopes. For example, through a microscope, a person might focus the eyes to one meter distance although it can present an image at six meters distance.
Characteristics
Ordinarily, when someone looks at an object at, say, one meter from the eyes, the eyes make reflex adjustments so the object appears single and clear. That is, the eyes converge on the object, to bring its image in each eye onto the central part of each retina, the fovea. This ensures that the person sees one object instead of two, and is referred to as singleness of vision or binocular fusion. The focussing of each eye, its accommodation, is adjusted so the retinal image of the object is as sharp as possible. This is done via contraction of the ciliary muscles controlling the shape of the crystalline lens of the eye. Although convergence and accommodation are separate processes, they normally operate synergistically.
When someone looks into an optical instrument, such as a microscope, vision is far from ordinary. A microscope might force the person to use only one eye, it presents the person with a limited field of view, it presents a magnified view, and it allows the person to adjust the focus of the instrument for any viewing distance. Ideally, the person will choose a focus adjustment on the instrument that allows the eyes to have relaxed accommodation—that is to present the image(s) at a distance of about 6 meters, or optical infinity. However, most people tend to accommodate to nearer than 6 m. It is this too-close focussing of the eyes that is instrument myopia.
Accommodating to a distance nearer than 6 meters makes the ciliary muscles work harder than they need to, leading to fatigue. Some binocular microscopes are designed so that the vergence of the eyes is correct for a 6-meter viewing distance. Accommodating to a closer distance will tend to converge the eyes, leading to double vision.
According to Wesner and Miller (1986), instrument myopia is promoted when the viewing is with one eye, when the field of view is small, and when the luminance is low, concluding that these are consistent with accommodation's going towards a person's dark focus, which is about one meter from the eyes.
Wesner and Miller also said it is possible that a person's knowledge that the viewed object is very close (on the microscope stage) contributes to instrument myopia. They said that instrument myopia is minimised by using a binocular microscope that forces the person's vergence angle to be small.
History
Richards attributed early research into instrument myopia to H. Imbert in 1899. Early mention of the term occurred in 1970, or earlier.
References
Eye
Vision
Microscopes | Instrument myopia | [
"Chemistry",
"Technology",
"Engineering"
] | 612 | [
"Microscopes",
"Measuring instruments",
"Microscopy"
] |
42,905,501 | https://en.wikipedia.org/wiki/Polyhedral%20terrain | In computational geometry, a polyhedral terrain in three-dimensional Euclidean space is a polyhedral surface that intersects every line parallel to some particular line in a connected set (i.e., a point or a line segment) or the empty set. Without loss of generality, we may assume that the line in question is the z-axis of the Cartesian coordinate system. Then a polyhedral terrain is the image of a piecewise-linear function in x and y variables.
The polyhedral terrain is a generalization of the two-dimensional geometric object, the monotone polygonal chain.
As the name may suggest, a major application area of polyhedral terrains include geographic information systems to model real-world terrains.
Representation
A polyhedral model may be represented in terms of the partition of the plane into polygonal regions, each region being associated with a plane patch which is the image of points of the region under the piecewise-linear function in question.
Problems
There are a number of problems in computational geometry which involve polyhedral terrains.
References
Computational geometry
Surfaces
Polyhedra | Polyhedral terrain | [
"Mathematics"
] | 221 | [
"Computational geometry",
"Computational mathematics"
] |
42,906,061 | https://en.wikipedia.org/wiki/Total%20position%20spread | In physics, the total position-spread (TPS) tensor is a quantity originally introduced in the modern theory of electrical conductivity. In the case of molecular systems, this tensor measures the fluctuation of the electrons around their mean positions, which corresponds to the delocalization of the electronic charge within a molecular system. The total position-spread can discriminate between metals and insulators taking information from the ground state wave function. This quantity can be very useful as an indicator to characterize Intervalence charge transfer processes, the bond nature of molecules (covalent, ionic, or weakly bonded), and Metal–insulator transition.
Overview
The Localization Tensor (LT) is a per electron quantity proposed in the context of the theory of Kohn to characterize electrical conductivity properties. In 1964, Kohn realized that electrical conductivity is more related to the proper delocalization of the wave function than a simple bandgap. In fact, he proposed that a qualitative difference between insulators and conductors also manifests as a different organization of the electrons in their ground state where one has that: the wave function is strongly localized in insulators and very delocalized in conductors.
The interesting outcome of this theory is: i) it relates the classical idea of localized electrons as a cause of insulating state; ii) the needed information can be recovered from the ground state wave function because in the insulated regime the wave function breaks down as a sum of disconnected terms.
It is until 1999 that Resta and coworkers found a way to define the Kohn delocalization by proposing the already mentioned Localization Tensor. The LT is defined as a second order moment cumulant of the position operator divided by the number of electrons in the system. The key property of the LT is that: it diverges for metals while it takes finite values for insulators in the Thermodynamic limit.
Recently, the global quantity (the LT not divided by the number of electrons) has been introduced to study molecules and named Total Position-Spread tensor.
Theory
Spin-summed total position-spread (SS-TPS)
The total position spread Λ is defined as the second moment cumulant of the total electron position operator, and its units are in length square (e.g. bohr²). In order to compute this quantity, one has to take into account the position operator and its tensorial square. For a system of n electrons, the position operator and its Cartesian components are defined as:
(total position)
Where the i index runs over the number of electrons. Each component of the position operator is a one-electron operator, they can be represented in second quantization as follows:
where i,j run over orbitals. The expectation values of the position components are the first moments of the electrons' position.
Now we consider the tensorial square (second moment). In this sense, there are two types of them:
in quantum chemistry programs like MOLPRO or DALTON the second moment operator is a tensor defined as the sum of the tensor squares of the positions of a single electron. Then, this is a one-electron operator s defined by its Cartesian components: where index i runs over the number of electrons.
there is also the square of the total position operator . This is a two-electron operator S, and also defined by its Cartesian components: where indices i,j run over electrons.
The second moment of the position becomes then the sum of the one- and two-electron operators already defined:
Given a n-electron wave function , one wants to compute the second moment cumulant of it. A cumulant is a linear combination of moments so we have:
Spin-partitioned total position-spread (SP-TPS)
The position operator can be partitioned according to spin components.
From the one-particle operator it is possible to define the total spin-partitioned position operator as:
Therefore, the total position operator can be expressed by the sum of the two spin parts and :
and the square of the total position operator decomposes as:
Thus, there are four joint second moment cumulant of the spin-partitioned position operator:
Applications
Model Hamiltonians
Hubbard model
The Hubbard model is a very simple and approximate model employed in Condensed matter physics to describe the transition of materials from metals to insulators. It takes into account only two parameters: i) the kinetic energy or hopping integral denoted by -t; and ii) the on-site repulsion between electrons represented by U (see the example of 1D chain of hydrogen atoms).
In Figure 1, there are two limit cases to consider: larger values of -t/U representing a strong charge fluctuation (electrons free to move) whereas for small values of -t/U the electrons are completely localized. The spin-summed total position-spread is very sensitive to these changes because it increases faster than linearly when electrons start to present mobility (0.0 to 0.5 range of -t/U).
Heisenberg model
Monitor the wave function
The total position-spread is a powerful tool to monitor the wave function. In Figure 3 is shown the longitudinal spin-summed total position-spread (Λ∥) computed at full configuration interaction level for the H2 diatomic molecule. The Λ∥ in the high repulsive region shows a value that is lower than in the asymptotic limit. This is a consequence of nuclei being near to each other's causing and enhancement of the effective nuclear charge that makes electrons to be more localized. When stretching the bond, the total position-spread starts growing until it reaches a maximum (strong delocalization of the wave function) before the bond is broken. Once the bond is broken, the wave function becomes a sum of disconnected localized regions, and the tensor decreases until it reaches twice the value of the atomic limit (1 bohr² for each hydrogen atom).
Spin delocalization
When the total position-spread tensor is partitioned according to spin (spin-partitioned total position-spread), it becomes a powerful tool to describe spin delocalization in the insulating regime. In Figure 4 is shown the longitudinal spin-partitioned total position-spread (Λ∥) computed at full configuration interaction level for the H2 diatomic molecule. The horizontal line at 0 bohr2 divides the same spin (positive values) and different spin (negative values) contributions of the spin partitioned total position-spread. Unlike the spin-summed total position-spread that saturates to the atomic value for R>5, the spin-partitioned total position-spread diverges as R2 indicating that there is a strong spin delocalization. The spin-partitioned total position-spread can also be seen as a measure of how strong the electron correlation is.
Properties
The total position-spread is a cumulant and thus it possesses the following properties:
Cumulants can be explicitly represented only by moments of lower or equal order.
Cumulants are a linear combination of the products of these moments of lower or equal order.
Cumulants are additive. This is a very important property when studying molecular systems because it means that the total position-spread tensor shows size consistency.
A diagonal element of the cumulant tensor is the variance (see also this article), and it is always a positive value.
Cumulants also are invariant under the translation of the origin of when they are of order ≥ 2. The total position-spread tensor being a second-order cumulant, is invariant under the translation of the origin.
The total position-spread is more sensitive to the variation of the wave function than the energy, which makes it a good indicator for instance in a Metal–insulator transition situation.
References
Tensors
Condensed matter physics | Total position spread | [
"Physics",
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"Tensors",
"Phases of matter",
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"Matter"
] |
42,906,494 | https://en.wikipedia.org/wiki/Time-Sensitive%20Networking | Time-Sensitive Networking (TSN) is a set of standards under development by the Time-Sensitive Networking task group of the IEEE 802.1 working group. The TSN task group was formed in November 2012 by renaming the existing Audio Video Bridging Task Group and continuing its work. The name changed as a result of the extension of the working area of the standardization group. The standards define mechanisms for the time-sensitive transmission of data over deterministic Ethernet networks.
The majority of projects define extensions to the IEEE 802.1Q Bridges and Bridged Networks, which describes virtual LANs and network switches. These extensions in particular address transmission with very low latency and high availability. Applications include converged networks with real-time audio/video streaming and real-time control streams which are used in automotive applications and industrial control facilities.
Background
Standard information technology network equipment has no concept of "time" and cannot provide synchronization and precision timing. Delivering data reliably is more important than delivering within a specific time, so there are no constraints on delay or synchronization precision. Even if the average hop delay is very low, individual delays can be unacceptably high. Network congestion is handled by throttling and retransmitting dropped packets at the transport layer, but there are no means to prevent congestion at the link layer. Data can be lost when the buffers are too small or the bandwidth is insufficient, but excessive buffering adds to the delay, which is unacceptable when low deterministic delays are required.
The different AVB/TSN standards documents specified by IEEE 802.1 can be grouped into three basic key component categories that are required for a complete real-time communication solution based on switched Ethernet networks with deterministic quality of service (QoS) for point-to-point connections. Each and every standard specification can be used on its own and is mostly self-sufficient. However, only when used together in a concerted way, TSN as a communication system can achieve its full potential. The three basic components are:
Time synchronization: All devices that are participating in real-time communication need to have a common understanding of time
Scheduling and traffic shaping: All devices that are participating in real-time communication adhere to the same rules in processing and forwarding communication packets
Selection of communication paths, path reservations and fault-tolerance: All devices that are participating in real-time communication adhere to the same rules in selecting communication paths and in reserving bandwidth and time slots, possibly utilizing more than one simultaneous path to achieve fault-tolerance
Applications which need a deterministic network that behaves in a predictable fashion include audio and video, initially defined in Audio Video Bridging (AVB); control networks that accept inputs from sensors, perform control loop processing, and initiate actions; safety-critical networks that implement packet and link redundancy; and mixed media networks that handle data with varying levels of timing sensitivity and priority, such as vehicle networks that support climate control, infotainment, body electronics, and driver assistance. The IEEE AVB/TSN suite serves as the foundation for deterministic networking to satisfy the common requirements of these applications.
AVB/TSN can handle rate-constrained traffic, where each stream has a bandwidth limit defined by minimum inter-frame intervals and maximal frame size, and time-trigger traffic with an exact accurate time to be sent. Low-priority traffic is passed on best-effort base, with no timing and delivery guarantees.
Time Synchronization
In contrast to standard Ethernet according to IEEE 802.3 and Ethernet bridging according to IEEE 802.1Q, time is very important in TSN networks. For real-time communication with hard, non-negotiable time boundaries for end-to-end transmission latencies, all devices in this network need to have a common time reference and therefore, need to synchronize their clocks among each other. This is not only true for the end devices of a communication stream, such as an industrial controller and a manufacturing robot, but also true for network components, such as Ethernet switches. Only through synchronized clocks, it is possible for all network devices to operate in unison and execute the required operation at exactly the required point in time.
Although time synchronization in TSN networks can be achieved with GPS clock, this is costly and there is no guarantee that the endpoint device has access to the radio or satellite signal at all times. Due to these constraints, time in TSN networks is usually distributed from one central time source directly through the network itself using the IEEE 1588 Precision Time Protocol, which utilizes Ethernet frames to distribute time synchronization information. IEEE 802.1AS is a tightly constrained subset of IEEE 1588 with sub-microsecond precision and extensions to support synchronisation over WiFi radio (IEEE 802.11). The idea behind this profile is to narrow the huge list of different IEEE 1588 options down to a manageable few critical options that are applicable to home networks or networks in automotive or industrial automation environments.
IEEE 802.1AS Timing and Synchronization for Time-Sensitive Applications
IEEE 802.1AS-2011 defines the Generalized Precision Time Protocol (gPTP) profile which, like all profiles of IEEE 1588, selects among the options of 1588, but also generalizes the architecture to allow PTP to apply beyond wired Ethernet networks.
To account for data path delays, the gPTP protocol measures the frame residence time within each bridge (the time required for receiving, processing, queuing and transmission of timing information from the ingress to egress ports), and the link latency of each hop (a propagation delay between two adjacent bridges). These calculated delays are then referenced to the GrandMaster (GM) clock in a bridge elected by the Best Master Clock Algorithm, a clock spanning tree protocol to which all Clock Master (CM) and endpoint devices attempt to synchronize. Any device which does not synchronize to timing messages is outside of the timing domain boundaries (Figure 2).
Synchronization accuracy depends on precise measurements of link delay and frame residence time. 802.1AS uses 'logical syntonization', where a ratio between local clock and GM clock frequencies is used to calculate synchronized time, and a ratio between local and GM clock frequencies to calculate propagation delay.
IEEE802.1AS-2020 introduces improved time measurement accuracy and support for multiple time domains for redundancy.
Scheduling and traffic shaping
Scheduling and traffic shaping allows for the coexistence of different traffic classes with different priorities on the same network - each with different requirements to available bandwidth and end-to-end latency.
Traffic shaping refers to the process of distributing frames/packets evenly in time to smooth out the traffic. Without traffic shaping at sources and bridges, the packets will "bunch", i.e. agglomerate into bursts of traffic, overwhelming the buffers in subsequent bridges/switches along the path.
Standard bridging according to IEEE 802.1Q uses a strict priority scheme with eight distinct priorities. On the protocol level, these priorities are visible in the Priority Code Point (PCP) field in the 802.1Q VLAN tag of a standard Ethernet frame. These priorities already distinguish between more important and less important network traffic, but even with the highest of the eight priorities, no absolute guarantee for an end-to-end delivery time can be given. The reason for this is buffering effects inside the Ethernet switches. If a switch has started the transmission of an Ethernet frame on one of its ports, even the highest priority frame has to wait inside the switch buffer for this transmission to finish. With standard Ethernet switching, this non-determinism cannot be avoided. This is not an issue in environments where applications do not depend on the timely delivery of single Ethernet frames - such as office IT infrastructures. In these environments, file transfers, emails or other business applications have limited time sensitivity themselves and are usually protected by other mechanisms further up the protocol stack, such as the Transmission Control Protocol. In industrial automation (Programmable Logic Controller (PLC) with an industrial robot) and automotive car environments, where closed loop control or safety applications are using the Ethernet network, reliable and timely delivery is of utmost importance. AVB/TSN enhances standard Ethernet communication by adding mechanisms to provide different time slices for different traffic classes and ensure timely delivery with soft and hard real-time requirements of control system applications. The mechanism of utilizing the eight distinct VLAN priorities is retained, to ensure complete backward compatibility to non-TSN Ethernet. To achieve transmission times with guaranteed end-to-end latency, one or several of the eight Ethernet priorities can be individually assigned to already existing methods (such as the IEEE 802.1Q strict priority scheduler) or new processing methods, such as the IEEE 802.1Qav credit-based traffic shaper, IEEE 802.1Qbv time-aware shaper, or IEEE 802.1Qcr asynchronous shaper.
Time-sensitive traffic has several priority classes. For credit-based shaper 802.1Qav, Stream Reservation Class A is the highest priority with a transmission period of ; Class B has the second-highest priority with a maximum transmission period of . Traffic classes shall not exceed their preconfigured maximum bandwidth (75% for audio and video applications). The maximum number of hops is 7. The worst-case latency requirement is defined as for Class A and for Class B, but has been shown to be unreliable. The per-port peer delay provided by gPTP and the network bridge residence delay are added to calculate the accumulated delays and ensure the latency requirement is met. Control traffic has the third-highest priority and includes gPTP and SRP traffic. Time-aware scheduler 802.1Qbv introduces Class CDT for realtime control data from sensors and command streams to actuators, with worst-case latency of 100 μs over 5 hops, and a maximum transmission period of 0.5 ms. Class CDT takes the highest priority over classes A, B, and control traffic.
AVB credit-based scheduler
IEEE 802.1Qav Forwarding and queuing enhancements for time-sensitive streams
IEEE 802.1Qav Forwarding and Queuing Enhancements for Time-Sensitive Streams defines traffic shaping using priority classes, which is based on a simple form of "leaky bucket" credit-based fair queuing. 802.1Qav is designed to reduce buffering in receiving bridges and endpoints.
The credit-based shaper defines credits in bits for two separate queues, dedicated to Class A and Class B traffic. Frame transmission is only allowed when credit is non-negative; during transmission the credit decreases at a rate called sendSlope:
The credit increases at a rate idleSlope if frames are waiting for other queues to be transmitted:
Thus the idleSlope is the bandwidth reserved for the queue by the bridge, and the sendSlope is the transmission rate of the port MAC service.
If the credit is negative and no frames are transmitted, credit increases at idleSlope rate until zero is reached. If an AVB frame cannot be transmitted because a non-AVB frame is in transmission, credit accumulates at idleSlope rate but positive credit is allowed.
Additional limits hiCredit and loCredit are derived from the maximum frame size and maximum interference size, the idleSlope/sendSlope, and the maximum port transmission rate.
Reserved AV stream traffic frames are forwarded with high priority over non-reserved best-effort traffic, subject to credit-based traffic shaping rules which may require them to wait for certain amount of credits. This protects best-effort traffic by limiting maximum AV stream burst. The frames are scheduled very evenly, though only on an aggregate basis, to smooth out the delivery times and reduce bursting and bunching, which can lead to buffer overflows and packet drops that trigger retransmissions. The increased buffering delay makes re-transmitted packets obsolete by the time they arrive, resulting in frame drops which reduces the quality of AV applications.
Though credit-based shaper provides fair scheduling for low-priority packets and smooths out traffic to eliminate congestion, unfortunately, average delay increases up to 250 μs per hop, which is too high for control applications, whereas a time-aware shaper (IEEE 802.1Qbv) has a fixed cycle delay from 30 μs to several milliseconds, and typical delay of 125 μs. Deriving guaranteed upper bounds on delays in TSN is non-trivial and is currently being researched, e.g., by using the mathematical framework Network Calculus.
IEEE 802.1Qat Stream Reservation Protocol
IEEE 802.1Qat Stream Reservation Protocol (SRP) is a distributed peer-to-peer protocol that specifies admission controls based on resource requirements of the flow and available network resources.
SRP reserves resources and advertises streams from the sender/source (talker) to the receivers/destinations (listeners); it works to satisfy QoS requirements for each stream and guarantee the availability of sufficient network resources along the entire flow transmission path.
The traffic streams are identified and registered with a 64-bit StreamID, made up of the 48-bit MAC address (EUI) and 16-bit UniqueID to identify different streams from the one source.
SRP employs variants of Multiple Registration Protocol (MRP) to register and de-register attribute values on switches/bridges/devices - the Multiple MAC Registration Protocol (MMRP), the Multiple VLAN Registration Protocol (MVRP), and the Multiple Stream Registration Protocol (MSRP).
The SRP protocol essentially works in the following sequence:
Advertise a stream from a talker
Register the paths along data flow
Calculate worst-case latency
Create an AVB domain
Reserve the bandwidth
Resources are allocated and configured in both the end nodes of the data stream and the transit nodes along the data flow path, with an end-to-end signaling mechanism to detect the success/failure. Worst-case latency is calculated by querying every bridge.
Reservation requests use the general MRP application with MRP attribute propagation mechanism. All nodes along the flow path pass the MRP Attribute Declaration (MAD) specification which describes the stream characteristics so that bridges could allocate the necessary resources.
If a bridge is able to reserve the required resources, it propagates the advertisement to the next bridge; otherwise, a 'talker failed' message is raised. When the advertise message reaches the listener, it replies with 'listener ready' message that propagates back to the talker.
Talker advertise and listener ready messages can be de-registered, which terminates the stream.
Successful reservation is only guaranteed when all intermediate nodes support SRP and respond to advertise and ready messages; in Figure 2 above, AVB domain 1 is unable to connect with AVB domain 2.
SRP is also used by TSN/AVB standards for frame priorities, frame scheduling, and traffic shaping
Enhancements to AVB scheduling
IEEE 802.1Qcc Enhancements to SRP
SRP uses decentralized registration and reservation procedure, multiple requests can introduce delays for critical traffic. IEEE 802.1Qcc-2018 "Stream Reservation Protocol (SRP) Enhancements and Performance Improvements" amendment reduces the size of reservation messages and redefines timers so they trigger updates only when link state or reservation is changed. To improve TSN administration on large scale networks, each User Network Interface (UNI) provides methods for requesting Layer 2 services, supplemented by Centralized Network Configuration (CNC) to provide centralized reservation and scheduling, and remote management using NETCONF/RESTCONF protocols and IETF YANG/NETCONF data modeling.
CNC implements a per-stream request-response model, where SR class is not explicitly used: end-stations send requests for a specific stream (via edge port) without knowledge of the network configuration, and CNC performs stream reservation centrally. MSRP only runs on the link to end-stations as an information carrier between CNC and end-stations, not for stream reservation. Centralized User Configuration (CUC) is an optional node that discovers end stations, their capabilities and user requirements, and configures delay-optimized TSN features (for closed-loop IACS applications). Seamless interop with Resource Reservation Protocol (RSVP) transport is provided.
802.1Qcc allows centralized configuration management to coexist with decentralized, fully distributed configuration of the SRP protocol, and also supports hybrid configurations for legacy AVB devices.
802.1Qcc can be combined with IEEE 802.1Qca Path Control and Reservation (PCR) and TSN traffic shapers.
IEEE 802.1Qch Cyclic Queuing and Forwarding (CQF)
While the 802.1Qav FQTSS/CBS works very well with soft real-time traffic, worst-case delays are both hop count and network topology dependent. Pathological topologies introduce delays, so buffer size requirements have to consider network topology.
IEEE 802.1Qch Cyclic Queuing and Forwarding (CQF), also known as the Peristaltic Shaper (PS), introduces double buffering which allows bridges to synchronize transmission (frame enqueue/dequeue operations) in a cyclic manner, with bounded latency depending only on the number of hops and the cycle time, completely independent of the network topology.
CQF can be used with the IEEE 802.1Qbv time-aware scheduler, IEEE 802.1Qbu frame preemption, and IEEE 802.1Qci ingress traffic policing.
IEEE 802.1Qci Per-Stream Filtering and Policing (PSFP)
IEEE 802.1Qci Per-Stream Filtering and Policing (PSFP) improves network robustness by filtering individual traffic streams. It prevents traffic overload conditions that may affect bridges and the receiving endpoints due to malfunction or Denial of Service (DoS) attacks.
The stream filter uses rule matching to allow frames with specified stream IDs and priority levels and apply policy actions otherwise. All streams are coordinated at their gates, similarly to the 802.1Qch signaling.
The flow metering applies predefined bandwidth profiles for each stream.
TSN scheduling and traffic shaping
IEEE 802.1Qbv Enhancements to Traffic Scheduling: Time-Aware Shaper (TAS)
The IEEE 802.1Qbv time-aware scheduler is designed to separate the communication on the Ethernet network into fixed length, repeating time cycles. Within these cycles, different time slices can be configured that can be assigned to one or several of the eight Ethernet priorities. By doing this, it is possible to grant exclusive use - for a limited time - to the Ethernet transmission medium for those traffic classes that need transmission guarantees and can't be interrupted. The basic concept is a time-division multiple access (TDMA) scheme. By establishing virtual communication channels for specific time periods, time-critical communication can be separated from non-critical background traffic.
Time-aware scheduler introduces Stream Reservation Class CDT for time-critical control data, with worst-case latency of 100 μs over 5 hops, and maximum transmission period of 0.5 ms, in addition to classes A and B defined for IEEE 802.1Qav credit-based traffic shaper. By granting exclusive access to the transmission medium and devices to time-critical traffic classes, the buffering effects in the Ethernet switch transmission buffers can be avoided and time-critical traffic can be transmitted without non-deterministic interruptions. One example for an IEEE 802.1Qbv scheduler configuration is visible in figure 1:
In this example, each cycle consists of two time slices. Time slice 1 only allows the transmission of traffic tagged with VLAN priority 3, and time slice 2 in each cycle allows for the rest of the priorities to be sent. Since the IEEE 802.1Qbv scheduler requires all clocks on all network devices (Ethernet switches and end devices) to be synchronized and the identical schedule to be configured, all devices understand which priority can be sent to the network at any given point in time. Since time slice 2 has more than one priority assigned to it, within this time slice, the priorities are handled according to standard IEEE 802.1Q strict priority scheduling.
This separation of Ethernet transmissions into cycles and time slices can be enhanced further by the inclusion of other scheduling or traffic shaping algorithms, such as the IEEE 802.1Qav credit-based traffic shaper. IEEE 802.1Qav supports soft real-time. In this particular example, IEEE 802.1Qav could be assigned to one or two of the priorities that are used in time slice two to distinguish further between audio/video traffic and background file transfers. The Time-Sensitive Networking Task Group specifies a number of different schedulers and traffic shapers that can be combined to achieve the nonreactive coexistence of hard real-time, soft real-time and background traffic on the same Ethernet infrastructure.
IEEE 802.1Qbv in more detail: Time slices and guard bands
When an Ethernet interface has started the transmission of a frame to the transmission medium, this transmission has to be completely finished before another transmission can take place. This includes the transmission of the CRC32 checksum at the end of the frame to ensure a reliable, fault-free transmission. This inherent property of Ethernet networks - again- poses a challenge to the TDMA approach of the IEEE 802.1Qbv scheduler. This is visible in figure 2:
Just before the end of time slice 2 in cycle n, a new frame transmission is started. Unfortunately, this frame is too large to fit into its time slice. Since the transmission of this frame cannot be interrupted, the frame infringes the following time slice 1 of the next cycle n+1. By partially or completely blocking a time-critical time slice, real-time frames can be delayed up to the point where they cannot meet the application requirements any longer. This is very similar to the actual buffering effects that happen in non-TSN Ethernet switches, so TSN has to specify a mechanism to prevent this from happening.
The IEEE 802.1Qbv time-aware scheduler has to ensure that the Ethernet interface is not busy with the transmission of a frame when the scheduler changes from one-time slice into the next. The time-aware scheduler achieves this by putting a guard band in front of every time slice that carries time-critical traffic. During this guard band time, no new Ethernet frame transmission may be started, only already ongoing transmissions may be finished. The duration of this guard band has to be as long as it takes the maximum frame size to be safely transmitted. For an Ethernet frame according to IEEE 802.3 with a single IEEE 802.1Q VLAN tag and including interframe spacing, the total length is: 1500 byte (frame payload) + 18 byte (Ethernet addresses, EtherType and CRC) + 4 byte (VLAN Tag) + 12 byte (Interframe spacing) + 8 byte (preamble and SFD) = 1542 byte.
The total time needed for sending this frame is dependent on the link speed of the Ethernet network. With Fast Ethernet and 100 Mbit/s transmission rate, the transmission duration is as follows:
In this case, the guard band has to be at least 123.36 μs long. With the guard band, the total bandwidth or time that is usable within a time slice is reduced by the length of the guard band. This is visible in figure 3
Note: to facilitate the presentation of the topic, the actual size of the guard band in figure 3 is not to scale, but is significantly smaller than indicated by the frame in figure 2.
In this example, the time slice 1 always contains high priority data (e.g. for motion control), while time slice 2 always contains best-effort data. Therefore, a guard band needs to be placed at every transition point into time slice 1 to protect the time slice of the critical data stream(s).
While the guard bands manage to protect the time slices with high priority, critical traffic, they also have some significant drawbacks:
The time that is consumed by a guard band is lost - it cannot be used to transmit any data, as the Ethernet port needs to be silent. Therefore, the lost time directly translates in lost bandwidth for background traffic on that particular Ethernet link.
A single time slice can never be configured smaller than the size of the guard band. Especially with lower speed Ethernet connections and growing guard band size, this has a negative impact on the lowest achievable time slice length and cycle time.
To partially mitigate the loss of bandwidth through the guard band, the standard IEEE 802.1Qbv includes a length-aware scheduling mechanism. This mechanism is used when store-and-forward switching is utilized: after the full reception of an Ethernet frame that needs to be transmitted on a port where the guard band is in effect, the scheduler checks the overall length of the frame. If the frame can fit completely inside the guard band, without any infringement of the following high priority slice, the scheduler can send this frame, despite an active guard band, and reduce the waste of bandwidth. This mechanism, however, cannot be used when cut-through switching is enabled, since the total length of the Ethernet frame needs to be known a priori. Therefore, when cut-through switching is used to minimize end-to-end latency, the waste of bandwidth will still occur. Also, this does not help with the minimum achievable cycle time. Therefore, length-aware scheduling is an improvement, but cannot mitigate all drawbacks that are introduced by the guard band.
IEEE 802.3br and 802.1Qbu Interspersing Express Traffic (IET) and Frame Preemption
To further mitigate the negative effects from the guard bands, the IEEE working groups 802.1 and 802.3 have specified the frame pre-emption technology. The two working groups collaborated in this endeavour since the technology required both changes in the Ethernet Media Access Control (MAC) scheme that is under the control of IEEE 802.3, as well as changes in the management mechanisms that are under the control of IEEE 802.1. Due to this fact, frame pre-emption is described in two different standards documents: IEEE 802.1Qbu for the bridge management component and IEEE 802.3br for the Ethernet MAC component.
Frame preemption defines two MAC services for an egress port, preemptable MAC (pMAC) and express MAC (eMAC). Express frames can interrupt transmission of preemptable frames. On resume, MAC merge sublayer re-assembles frame fragments in the next bridge.
Preemption causes computational overhead in the link interface, as the operational context shall be transitioned to the express frame.
Figure 4 gives a basic example how frame pre-emption works. During the process of sending a best effort Ethernet frame, the MAC interrupts the frame transmission just before the start of the guard band. The partial frame is completed with a CRC and will be stored in the next switch to wait for the second part of the frame to arrive. After the high priority traffic in time slice 1 has passed and the cycle switches back to time slice 2, the interrupted frame transmission is resumed. Frame pre-emption always operates on a pure link-by-link basis and only fragments from one Ethernet switch to the next Ethernet switch, where the frame is reassembled. In contrast to fragmentation with the Internet Protocol (IP), no end-to-end fragmentation is supported.
Each partial frame is completed by a CRC32 for error detection. In contrast to the regular Ethernet CRC32, the last 16 bits are inverted to make a partial frame distinguishable from a regular Ethernet frame. In addition, the start of frame delimiter (SFD) is changed.
The support for frame pre-emption has to be activated on each link between devices individually. To signal the capability for frame pre-emption on a link, an Ethernet switch announces this capability through the LLDP (Link Layer Discovery Protocol). When a device receives such an LLDP announcement on a network port and supports frame pre-emption itself, it may activate the capability. There is no direct negotiation and activation of the capability on adjacent devices. Any device that receives the LLDP pre-emption announcement assumes that on the other end of the link, a device is present that can understand the changes in the frame format (changed CRC32 and SFD).
Frame pre-emption allows for a significant reduction of the guard band. The length of the guard band is now dependent on the precision of the frame pre-emption mechanism: how small is the minimum size of the frame that the mechanism can still pre-empt. IEEE 802.3br specifies the best accuracy for this mechanism at 64 byte - due to the fact that this is the minimum size of a still valid Ethernet frame. In this case, the guard band can be reduced to a total of 127 byte: 64 byte (minimum frame) + 63 byte (remaining length that cannot be pre-empted). All larger frames can be pre-empted again and therefore, there is no need to protect against this size with a guard band.
This minimizes the best effort bandwidth that is lost and also allows for much shorter cycle times at slower Ethernet speeds, such as 100 Mbit/s and below. Since the pre-emption takes place in hardware in the MAC, as the frame passes through, cut-through switching can be supported as well, since the overall frame size is not needed a priori. The MAC interface just checks in regular 64 byte intervals whether the frame needs to be pre-empted or not.
The combination of time synchronization, the IEEE 802.1Qbv scheduler and frame pre-emption already constitutes an effective set of standards that can be utilized to guarantee the coexistence of different traffic categories on a network while also providing end-to-end latency guarantees. This will be enhanced further as new IEEE 802.1 specifications, such as 802.1Qch are finalized.
Shortcomings of IEEE 802.1Qbv/bu
Overall, the time-aware scheduler has high implementation complexity and its use of bandwidth is not efficient.
Task and event scheduling in endpoints has to be coupled with the gate scheduling of the traffic shaper in order to lower the latencies.
A critical shortcoming is some delay incurred when an end-point streams unsynchronized data, due to the waiting time for the next time-triggered window.
The time-aware scheduler requires tight synchronization of its time-triggered windows, so all bridges on the stream path must be synchronized. However synchronizing TSN bridge frame selection and transmission time is nontrivial even in moderately sized networks and requires a fully managed solution.
Frame preemption is hard to implement and has not seen wide industry support.
IEEE 802.1Qcr Asynchronous Traffic Shaping
Credit-based, time-aware and cyclic (peristaltic) shapers require network-wide coordinated time and utilize network bandwidth inefficiently, as they enforce packet transmission at periodic cycles. The IEEE 802.1Qcr Asynchronous Traffic Shaper (ATS) operates asynchronously based on local clocks in each bridge, improving link utilization for mixed traffic types, such as periodic with arbitrary periods, sporadic (event driven), and rate-constrained.
ATS employs the urgency-based scheduler (UBS) which prioritizes urgent traffic using per-class queuing and per-stream reshaping. Asynchronicity is achieved by interleaved shaping with traffic characterization based on Token Bucket Emulation, a token bucket emulation model, to eliminate the burstiness cascade effects of per-class shaping. The TBE shaper controls the traffic by average transmission rate, but allows a certain level of burst traffic. When there is a sufficient number of tokens in the bucket, transmission starts immediately; otherwise the queue's gate closes for the time needed to accumulate enough tokens.
The UBS is an improvement on Rate-Controlled Service Disciplines (RCSDs) to control selection and transmission of each individual frame at each hop, decoupling stream bandwidth from the delay bound by separation of rate control and packet scheduling, and using static priorities and First Come - First Serve and Earliest Due - Date First queuing.
UBS queuing has two levels of hierarchy: per-flow shaped queues, with fixed priority assigned by the upstream sources according to application-defined packet transmission times, allowing arbitrary transmission period for each stream, and shared queues that merge streams with the same internal priority from several shapers. This separation of queuing has low implementation complexity while ensuring that frames with higher priority will bypass the lower priority frames.
The shared queues are highly isolated, with policies for separate queues for frames from different transmitters, the same transmitter but different priority, and the same transmitter and priority but a different priority at the receiver. Queue isolation prevents propagation of malicious data, assuring that ordinary streams will get no interference, and enables flexible stream or transmitter blocking by administrative action.
The minimum number of shared queues is the number of ports minus one, and more with additional isolation policies. Shared queues have scheduler internal fixed priority, and frames are transmitted on the First Come First Serve principle.
Worst case clock sync inaccuracy does not decrease link utilization, contrary to time-triggered approaches such as TAS (Qbv) and CQF (Qch).
Selection of communication paths and fault-tolerance
IEEE 802.1Qca Path Control and Reservation (PCR)
IEEE 802.1Qca Path Control and Reservation (PCR) specifies extensions to the Intermediate Station to Intermediate Station (IS-IS) protocol to configure multiple paths in bridged networks.
The IEEE 802.1Qca standard uses Shortest Path Bridging (SPB) with a software-defined networking (SDN) hybrid mode - the IS-IS protocol handles basic functions, while the SDN controller manages explicit paths using Path Computation Elements (PCEs) at dedicated server nodes.
IEEE 802.1Qca integrates control protocols to manage multiple topologies, configure an explicit forwarding path (a predefined path for each stream), reserve bandwidth, provides data protection and redundancy, and distribute flow synchronization and flow control messages. These are derived from Equal Cost Tree (ECT), Multiple Spanning Tree Instance (MSTI) and Internal Spanning Tree (IST), and Explicit Tree (ET) protocols.
IEEE 802.1CB Frame Replication and Elimination for Reliability (FRER)
IEEE 802.1CB Frame Replication and Elimination for Reliability (FRER) sends duplicate copies of each frame over multiple disjoint paths, to provide proactive seamless redundancy for control applications that cannot tolerate packet losses.
The packet replication can use traffic class and path information to minimize network congestion. Each replicated frame has a sequence identification number, used to re-order and merge frames and to discard duplicates.
FRER requires centralized configuration management and needs to be used with 802.1Qcc and 802.1Qca. Industrial fault-tolerance HSR and PRP specified in IEC 62439-3 are supported.
Current projects
IEEE 802.1CS Link-Local Registration Protocol
MRP state data for a stream takes 1500 bytes. With additional traffic streams and larger networks, the size of the database proportionally increases and MRP updates between bridge neighbors significantly slow down. The Link-Local Registration Protocol (LRP) is optimized for a larger database size of about 1 Mbyte with efficient replication that allows incremental updates. Unresponsive nodes with stale data are automatically discarded. While MRP is application specific, with each registered application defining its own set of operations, LRP is application neutral.
IEEE 802.1Qdd Resource Allocation Protocol
SRP and MSRP are primarily designed for AV applications - their distributed configuration model is limited to Stream Reservation (SR) Classes A and B defined by the Credit-Based Shaper (CBS), whereas IEEE 802.1Qcc includes a more centralized CNC configuration model supporting all new TSN features such as additional shapers, frame preemption, and path redundancy.
IEEE P802.1Qdd project updates the distributed configuration model by defining new peer-to-peer Resource Allocation Protocol signaling built upon P802.1CS Link-local Registration Protocol. RAP will improve scalability and provide dynamic reservation for a larger number of streams with support for redundant transmission over multiple paths in 802.1CB FRER, and autoconfiguration of sequence recovery.
RAP supports the 'topology-independent per-hop latency calculation' capability of TSN shapers such as 802.1Qch Cyclic Queuing and Forwarding (CQF) and P802.1Qcr Asynchronous Traffic Shaping (ATS). It will also improve performance under high load and support proxying and enhanced diagnostics, all while maintaining backward compatibility and interoperability with MSRP.
IEEE 802.1ABdh Link Layer Discovery Protocol v2
IEEE P802.1ABdh Station and Media Access Control Connectivity Discovery - Support for Multiframe Protocol Data Units (LLDPv2) updates LLDP to support IETF Link State Vector Routing protocol and improve efficiency of protocol messages.
YANG data models
The IEEE 802.1Qcp standard implements the YANG data model to provide a Universal Plug-and-Play (uPnP) framework for status reporting and configuration of equipment such as Media Access Control (MAC) Bridges, Two-Port MAC Relays (TPMRs), Customer Virtual Local Area Network (VLAN) Bridges, and Provider Bridges, and to support the 802.1X Security and 802.1AX Datacenter Bridging standards.
YANG is a Unified Modeling Language (UML) for configuration and state data, notifications, and remote procedure calls, to set up device configuration with network management protocols such as NETCONF/RESTCONF.
DetNet
The IETF Deterministic Networking (DetNet) Working Group is focusing to define deterministic data paths with high reliability and bounds on latency, loss, and packet delay variation (jitter), such as audio and video streaming, industrial automation, and vehicle control.
The goals of Deterministic Networking are to migrate time-critical, high-reliability industrial and audio-video applications from special-purpose Fieldbus networks to IP packet networks. To achieve these goals, DetNet uses resource allocation to manage buffer sizes and transmission rates in order to satisfy end-to-end latency requirements. Service protection against failures with redundancy over multiple paths and explicit routes to reduce packet loss and reordering. The same physical network shall handle both time-critical reserved traffic and regular best-effort traffic, and unused reserved bandwidth shall be released for best-effort traffic.
DetNet operates at the IP Layer 3 routed segments using a software-defined networking layer to provide IntServ and DiffServ integration, and delivers services over lower Layer 2 bridged segments using technologies such as MPLS and IEEE 802.1 AVB/TSN.
Traffic Engineering (TE) routing protocols translate DetNet flow specification to AVB/TSN controls for queuing, shaping, and scheduling algorithms, such as IEEE 802.1Qav credit-based shaper, IEEE802.1Qbv time-triggered shaper with a rotating time scheduler, IEEE802.1Qch synchronized double buffering, 802.1Qbu/802.3br Ethernet packet pre-emption, and 802.1CB frame replication and elimination for reliability. Also protocol interworking defined by IEEE 802.1CB is used to advertise TSN sub-network capabilities to DetNet flows via the Active Destination MAC and VLAN Stream identification functions. DetNet flows are matched by destination MAC address, VLAN ID and priority parameters to Stream ID and QoS requirements for talkers and listeners in the AVB/TSN sub-network.
Standards
Related projects:
References
External links
IEEE 802.1 Time-Sensitive Networking Task Group
IEEE 802.1 public document archive
Specification for IEEE TSN Standards from Avnu Alliance
Real-time Ethernetredefined
Time Sensitive Networking (TSN) Vision: Unifying Business & Industrial Automation
Is TSN Activity Igniting Another Fieldbus WAR?
research project related to TSN applications in aircraft
TSN Training, Marc Boyer (ONERA), Pierre Julien Chaine (Airbus Defence and Space)
IEEE standards
Ethernet
Industrial Ethernet
Control engineering
Audio engineering
Automotive electronics
Network protocols | Time-Sensitive Networking | [
"Technology",
"Engineering"
] | 8,442 | [
"Computer standards",
"Control engineering",
"Industrial Ethernet",
"Electrical engineering",
"Audio engineering",
"IEEE standards"
] |
42,908,722 | https://en.wikipedia.org/wiki/Model%20order%20reduction | Model order reduction (MOR) is a technique for reducing the computational complexity of mathematical models in numerical simulations. As such it is closely related to the concept of metamodeling, with applications in all areas of mathematical modelling.
Overview
Many modern mathematical models of real-life processes pose challenges when used in numerical simulations, due to complexity and large size (dimension). Model order reduction aims to lower the computational complexity of such problems, for example, in simulations of large-scale dynamical systems and control systems. By a reduction of the model's associated state space dimension or degrees of freedom, an approximation to the original model is computed which is commonly referred to as a reduced order model.
Reduced order models are useful in settings where it is often unfeasible to perform numerical simulations using the complete full order model. This can be due to limitations in computational resources or the requirements of the simulations setting, for instance real-time simulation settings or many-query settings in which a large number of simulations needs to be performed. Examples of Real-time simulation settings include control systems in electronics and visualization of model results while examples for a many-query setting can include optimization problems and design exploration. In order to be applicable to real-world problems, often the requirements of a reduced order model are:
A small approximation error compared to the full order model.
Conservation of the properties and characteristics of the full order model (E.g. stability and passivity in electronics).
Computationally efficient and robust reduced order modelling techniques.
It is interesting to note that in some cases (e.g. constrained lumping of polynomial differential equations) it is possible to have a null approximation error, resulting in an exact model order reduction.
Methods
Contemporary model order reduction techniques can be broadly classified into 5 classes:
Proper orthogonal decomposition methods.
Reduced basis methods.
Balancing methods
Simplified physics or operational based reduction methods.
Nonlinear manifold methods.
The simplified physics approach can be described to be analogous to the traditional mathematical modelling approach, in which a less complex description of a system is constructed based on assumptions and simplifications using physical insight or otherwise derived information. However, this approach is not often the topic of discussion in the context of model order reduction as it is a general method in science, engineering, and mathematics.
The remaining listed methods fall into the category of projection-based reduction. Projection-based reduction relies on the projection of either the model equations or the solution onto a basis of reduced dimensionality compared to the original solution space. Methods that also fall into this class but are perhaps less common are:
Proper generalized decomposition
Matrix interpolation
Transfer function interpolation
Piecewise tangential interpolation
Loewner framework
(Empirical) cross Gramian
Krylov subspace methods
There are also nonintrusive model reduction methods that learn reduced models from data without requiring knowledge about the governing equations and internals of the full, high-fidelity model. Nonintrusive methods learn a low-dimensional approximation space or manifold and the reduced operators that represent the reduced dynamics from data. Methods that are non-intrusive include:
Dynamic mode decomposition
Operator inference
Loewner framework
Implementations
RBmatlab: A MATLAB library containing all reduced simulation approaches for linear and nonlinear, affine or arbitrarily parameter dependent evolution problems with finite element, finite volume or local discontinuous Galerkin discretizations.
Model Reduction inside ANSYS: implements a Krylov-based model order reduction for multiphysical finite element models in Ansys. Model simplification via Model Reduction inside Ansys is suitable for optimization strategies in component development as well as for integrating compact models into an overall system simulation in the fields of electronics, automotive or microsystems. Despite reduction, the examination parameters are retained, which means fast results can be achieved with regards to designs and system simulations.
pyMOR: pyMOR is a software library for building model order reduction applications with the Python programming language. Its main focus lies on the application of reduced basis methods to parameterized partial differential equations. All algorithms in pyMOR are formulated in terms of abstract interfaces for seamless integration with external high-dimensional PDE solvers. Moreover, pure Python implementations of finite element and finite volume discretizations using the NumPy/SciPy scientific computing stack are provided for getting started quickly.
emgr: Empirical Gramian Framework. Empirical gramians can be computed for linear and nonlinear control systems for purposes of model order reduction, uncertainty quantification or system identification. The emgr framework is a compact open source toolbox for gramian-based model reduction and compatible with OCTAVE and MATLAB.
KerMor: An object-oriented MATLAB© library providing routines for model order reduction of nonlinear dynamical systems. Reduction can be achieved via subspace projection and approximation of nonlinearities via kernels methods or DEIM. Standard procedures like the POD-Greedy method are readily implemented as well as advanced a-posteriori error estimators for various system configurations. KerMor also includes several working examples and some demo files to quickly get familiarized with the provided functionality.
JaRMoS: JaRMoS stands for "Java Reduced Model Simulations" and aims to enable import and simulation of various reduced models from multiple sources on any java-capable platform. So far support for RBmatlab, KerMor and rbMIT reduced models is present, where we can only import the rbMIT models that have previously been published with the rbAppMIT Android application. Extensions so far are a desktop-version to run reduced models and initial support for KerMor kernel-based reduced models is on the way.
MORLAB: Model Order Reduction Laboratory. This toolbox is a collection of MATLAB/OCTAVE routines for model order reduction of linear dynamical systems based on the solution of matrix equations. The implementation is based on spectral projection methods, e.g., methods based on the matrix sign function and the matrix disk function.
Dune-RB: A module for the Dune library, which realizes C++ template classes for use in snapshot generation and RB offline phases for various discretizations. Apart from single-core algorithms, the package also aims at using parallelization techniques for efficient snapshot generation.
libROM: Collection of C++ classes that compute model order reduction and hyper-reduction for systems of partial and ordinary differential equations. libROM includes scalable and parallel, adaptive methods for proper orthogonal decomposition, parallel, non-adaptive methods for hyper-reduction, and randomized singular value decomposition. libROM also includes the dynamic mode decomposition capability. libROM has physics-informed greedy sampling capability.
Pressio: Pressio is an open-source project aimed at alleviating the intrusive nature of projection-based reduced-order models for large-scale codes. The core of the project is a header-only C++ library that leverages generic programming to interface with shared or distributed memory applications using arbitrary data-types. Pressio provides numerous functionalities and solvers for performing model reduction, such as Galerkin and least-squares Petrov–Galerkin projections. The Pressio ecosystem also offers: (1) pressio4py, a Python binding library for ease of prototyping, (2) pressio-tutorials, a library also offering end-to-end demos that one can easily play with, which can be found at https://pressio.github.io/pressio-tutorials/, (3) pressio-tools, a library for large-scale SVD, QR and sample mesh, and (4) pressio-demoapps, a suite of 1d, 2d and 3d demo applications for testing ROMs and hyper-reduction.
Applications
Model order reduction finds application within all fields involving mathematical modelling and many reviews exist for the topics of electronics, fluid mechanics, hydrodynamics, structural mechanics, MEMS, Boltzmann equation, and design optimization.
Fluid mechanics
Current problems in fluid mechanics involve large dynamical systems representing many effects on many different scales. Computational fluid dynamics studies often involve models solving the Navier–Stokes equations with a number of degrees of freedom in the order of magnitude upwards of . The first usage of model order reduction techniques dates back to the work of Lumley in 1967, where it was used to gain insight into the mechanisms and intensity of turbulence and large coherent structures present in fluid flow problems. Model order reduction also finds modern applications in aeronautics to model the flow over the body of aircraft. An example can be found in Lieu et al in which the full order model of an F16 fighter-aircraft with over 2.1 million degrees of freedom, was reduced to a model of just 90 degrees of freedom. Additionally reduced order modeling has been applied to study rheology in hemodynamics and the fluid–structure interaction between the blood flowing through the vascular system and the vascular walls.
See also
Dimension reduction
Metamodeling
Principal component analysis
Singular value decomposition
Nonlinear dimensionality reduction
System identification
Iterative rational Krylov algorithm (IRKA)
References
Further reading
External links
Model Order Reduction Wiki
Model Reduction for Parametrized Systems
European Model Reduction Network
Numerical analysis
Mathematical modeling | Model order reduction | [
"Mathematics"
] | 1,861 | [
"Mathematical modeling",
"Applied mathematics",
"Computational mathematics",
"Mathematical relations",
"Numerical analysis",
"Approximations"
] |
42,909,270 | https://en.wikipedia.org/wiki/Anton%E2%80%93Schmidt%20equation%20of%20state | The Anton–Schmidt equation is an empirical equation of state for crystalline solids, e.g. for pure metals or intermetallic compounds.
Quantum mechanical investigations of intermetallic compounds show that the dependency of the pressure under isotropic deformation can be described empirically by
.
Integration of leads to the equation of state for the total energy. The energy required to compress a solid to volume is
which gives
.
The fitting parameters and are related to material properties, where
is the bulk modulus at equilibrium volume .
correlates with the Grüneisen parameter .
However, the fitting parameter does not reproduce the total energy of the free atoms.
The total energy equation is used to determine elastic and thermal material constants in quantum chemical simulation packages.
The equation of state has been used in cosmological contexts to describe the dark energy dynamics. However its use has been recently criticized since it appears disfavored than simpler equations of state adopted for the same purpose.
See also
Murnaghan equation of state
Rose–Vinet equation of state
Birch–Murnaghan equation of state
References
Solid mechanics
Equations of state | Anton–Schmidt equation of state | [
"Physics"
] | 225 | [
"Solid mechanics",
"Equations of physics",
"Statistical mechanics",
"Mechanics",
"Equations of state"
] |
42,910,885 | https://en.wikipedia.org/wiki/Hook-and-loop%20fastener | Hook-and-loop fasteners, commonly known as Velcro (a genericized trademark), hook-and-pile fasteners or touch fasteners are versatile fastening devices that allow two surfaces to be repeatedly attached and detached with ease. Invented in the mid-20th century, they are widely used in clothing, accessories, and various industrial and consumer applications. The fastener consists of two complementary components: one with tiny hooks and the other with soft loops. When pressed together, the hooks catch the loops, creating a secure but temporary bond. The fasteners can be separated by peeling or pulling the surfaces apart, often producing a distinctive ripping sound.
History
The original hook-and-loop fastener was conceived in 1941 by Swiss engineer George de Mestral, which he named velcro. The idea came to him one day after returning from a hunting trip with his dog in the Alps. He took a close look at the burs of burdock that kept sticking to his clothes and his dog's fur. He examined them under a microscope, and noted their hundreds of "hooks" that caught on anything with a loop, such as clothing, animal fur, or hair. He saw the possibility of binding two materials reversibly in a simple fashion if he could figure out how to duplicate the hooks and loops. Hook-and-loop is regarded by some like Steven Vogel or Werner Nachtigall as a key example of inspiration from nature or the copying of nature's mechanisms (called bionics or biomimesis).
The big breakthrough de Mestral made was to think about hook-and-eye closures on a greatly reduced scale. Hook-and-eye fasteners have been common for centuries, but what was new about hook-and-loop fasteners was the miniaturisation of the hooks and eyes. Shrinking the hooks led to the two other important differences. Firstly, instead of a single-file line of hooks, hook-and-loop fasteners have a two-dimensional surface. This was needed, because in decreasing the size of the hooks, the strength was also unavoidably lessened, thus requiring more hooks for the same strength. The other difference is that hook-and-loop has indeterminate match-up between the hooks and eyes. With larger hook-and-eye fasteners, each hook has its own eye. On a scale as small as that of hook-and-loop fasteners, matching up each of these hooks with the corresponding eye is impractical, thus leading to the indeterminate matching.
De Mestral's proposal was initially rejected by industry leaders when he took his idea to Lyon, which was then a center of weaving. He did manage to gain the assistance of one weaver, who produced two cotton strips based on de Mestral's designs. However, the cotton frayed and wore out in a relatively short period of time. As a result, de Mestral began to explore the use of synthetic fibers, believing that they would provide a more resilient product. De Mestral eventually selected nylon, on the reasoning that it does not easily fray or attract mold, is non-biodegradable, and could be produced in threads of varying thickness. Nylon had only recently been invented, and through trial and error de Mestral eventually discovered that, when sewn under hot infrared light, nylon forms small hook shapes. However, he had yet to figure out a way to mechanize the process and to make the looped side. Next he found that nylon thread, when woven in loops and heat-treated, retains its shape and is resilient; however, the loops had to be cut in just the right spot so that they could be fastened and unfastened many times. On the verge of giving up, a new idea came to him. He bought a pair of shears and trimmed the tops off the loops, thus creating hooks that would match up perfectly with the loops in the pile.
Mechanizing the process of weaving the hooks took eight years, and it took another year to create the loom that trimmed the loops after weaving them. In all, it took ten years to create a mechanized process that worked.
De Mestral submitted his idea for a patent in Switzerland in 1951, which was granted in 1955. Within a few years he obtained patents and began to open shops in Germany, Switzerland, Great Britain, Sweden, Italy, the Netherlands, Belgium, and Canada. In 1957 he branched out to the textile center of Manchester, New Hampshire in the United States.
Columnist Sylvia Porter made the first mention of the product in her column Your Money's Worth of August 25, 1958, writing, "It is with understandable enthusiasm that I give you today an exclusive report on this news: A 'zipperless zipper' has been invented – finally. The new fastening device is in many ways potentially more revolutionary than was the zipper a quarter-century ago."
A Montreal firm, Velek, Ltd., acquired the exclusive right to market the product in North and South America, as well as in Japan, with American Velcro, Inc. of New Hampshire, and Velcro Sales of New York, marketing the "zipperless zipper" in the United States.
De Mestral obtained patents in many countries right after inventing the fasteners, as he expected an immediate high demand. Partly due to its cosmetic appearance, though, hook-and-loop's integration into the textile industry took time. At the time, the fasteners looked like they had been made from leftover bits of cheap fabric, and thus were not sewn into clothing or used widely when it debuted in the early 1960s. It was also regarded as impractical.
A number of Velcro Corporation products were displayed at a fashion show at the Waldorf-Astoria hotel in New York in 1959, and the fabric got its first break when it was used in the aerospace industry to help astronauts maneuver in and out of bulky space suits. However, this reinforced the view among the populace that hook-and-loop was something with very limited utilitarian uses. The next major use hook-and-loop saw was with skiers, who saw the similarities between their outerwear and that of the astronauts, and thus saw the advantages of a suit that was easier to don and doff. Scuba and marine gear followed soon after. Having seen astronauts storing food pouches on walls, children's clothing makers came on board. As hook-and-loop fasteners only became widely used after NASA's adoption of it, NASA is popularly – and incorrectly – credited with its invention.
By the mid-1960s, hook-and-loop fasteners were used in the futuristic creations of fashion designers such as Pierre Cardin, André Courrèges and Paco Rabanne.
Later improvements included strengthening the filament by adding polyester.
In 1978, de Mestral's patent expired, prompting a flood of low-cost imitations from Taiwan, China and South Korea onto the market. Today, the trademark is the subject of more than 300 trademark registrations in over 159 countries. George de Mestral was inducted into the National Inventors Hall of Fame in the U.S. for his invention.
Strength
Various constructions and strengths are available. Fasteners made of Teflon loops, polyester hooks, and glass backing are used in aerospace applications, e.g. on Space Shuttles. The strength of the bond depends on how well the hooks are embedded in the loops, how much surface area is in contact with the hooks, and the nature of the force pulling it apart. If hook-and-loop is used to bond two rigid surfaces, such as auto body panels and frame, the bond is particularly strong because any force pulling the pieces apart is spread evenly across all hooks. Also, any force pushing the pieces together is disproportionately applied to engaging more hooks and loops. Vibration can cause rigid pieces to improve their bond. Full-body hook-and-loop suits have been made that can hold a person to a suitably covered wall.
When one or both of the pieces is flexible, e.g., a pocket flap, the pieces can be pulled apart with a peeling action that applies the force to relatively few hooks at a time. If a flexible piece is pulled in a direction parallel to the plane of the surface, then the force is spread evenly, as it is with rigid pieces.
Three ways to maximize the strength of a bond between the two flexible pieces are:
Increase the area of the bond, e.g. using larger pieces.
Ensure that the force is applied parallel to the plane of the fastener surface, such as bending around a corner or pulley.
Increase the number of hooks and loops per area unit.
Shoe closures can resist a large force with only a small amount of hook-and-loop fasteners. This is because the strap is wrapped through a slot, halving the force on the bond by acting as a pulley system (thus gaining a mechanical advantage), and further absorbing some of the force in friction around the tight bend. This layout also ensures that the force is parallel to the strips.
Advantages and disadvantages
Hook-and-loop fasteners are safe and maintenance free. There is only a minimal decline in effectiveness even after many fastenings and unfastenings. The tearing noise it makes can also be useful against pickpockets. This loud noise can also prove to be a liability, in particular on military attire such as the United States Army's Army Combat Uniform, where it can attract unwanted attention in a battlefield environment.
There are also some deficiencies: it tends to accumulate hair, dust, and fur in its hooks after a few months of regular use. The loops can become elongated or broken after extended use. The hooks often become attached to articles of clothing, especially loosely woven items like sweaters. This clothing may be damaged when one attempts to remove the hook-and-loop, even if the sides are separated slowly. It also absorbs moisture and perspiration when worn next to the skin, which means it will smell if not washed.
Applications
Because of their ease of use, hook-and-loop fasteners have been used for a wide variety of applications where a temporary bond is required. It is especially popular in clothing where it replaces buttons or zippers, and as a shoe fastener for children who have not yet learned to tie shoelaces. Hook-and-loop fasteners are used in adaptive clothing, which is designed for people with physical disabilities, the elderly, and the infirm, who may experience difficulty dressing themselves due to an inability to manipulate closures such as buttons and zippers.
Hook-and-loop-fastener (USA Patent No.: US8,469,996 B2) is used in humans as a temporary fascia expander prostheses to treat the abdominal compartment syndrome and when multiple abdominal entries are necessary to control and eliminate intra-abdominal pathology. Hook-and-loop fasteners held together a human heart during the first artificial heart surgery. It is used in nuclear power plants and army tanks to hold flashlights to walls. In cars, hook-and-loop fasteners are used to bond headliners, floor mats and speaker covers. It is used in the home when pleating draperies, holding carpets in place and attaching upholstery. Closures on backpacks, briefcases and notebooks often make use of hook-and-loop fasteners. Cloth diapers often make use of hook-and-loop fasteners. It is an integral part of games such as tag rugby and flag football, and is used in surfboard leashes and orthopaedic braces.
NASA makes significant use of hook-and-loop fasteners. Each Space Shuttle flew equipped with ten thousand inches of a special fastener made of Teflon loops, polyester hooks, and glass backing. Hook-and-loop fasteners are widely used, from the astronauts' suits, to anchoring equipment. In the near weightless conditions in orbit, hook-and-loop fasteners are used to temporarily hold objects and keep them from floating away. A patch is used inside astronauts' helmets where it serves as a nose scratcher. During mealtimes astronauts use trays that attach to their thighs using springs and fasteners. Hook-and-loop fasteners are also used aboard the International Space Station.
Guitar pedals are commonly attached to pedalboards with strips of hook-and-loop.
Variations
The Slidingly Engaging Fastener was developed to address several problems with common hook-and-loop fasteners.
Heavy-duty variants (such as "Dual Lock" or "Duotec") feature mushroom-shaped stems on each face of the fastener, providing an audible snap when the two faces mate. A strong pressure sensitive adhesive bonds each component to its substrate.
There is a silent version of hook-and-loop fasteners, sometimes called Quiet Closures.
Standards
ASTM D5169-98 (2010) Standard Test Method for Shear Strength (Dynamic Method) of Hook and Loop Touch Fasteners
ASTM D5170-98 (2010) Standard Test Method for Peel Strength ("T" Method) of Hook and Loop Touch Fasteners
ASTM D2050-11 Standard Terminology Relating to Fasteners and Closures Used with Textiles
Jumping
Velcro jumping is a game where people wearing hook-covered suits take a running jump and hurl themselves as high as possible at a loop-covered wall. The wall is inflated, and looks similar to other inflatable structures. It is not necessarily completely covered in the material—often there will be vertical strips of hooks. Sometimes, instead of a running jump, people use a small trampoline.
Television show host David Letterman immortalized this during the February 28, 1984 episode of Late Night with David Letterman on NBC. Letterman proved that with enough of the material a man could be hurled against a wall and stick, by performing this feat during the television broadcast.
Jumping went beyond David Letterman, with amusement companies renting walls and jumpsuits for $400–500 a day. It was also done on a regular basis in pubs in both New York and New Zealand, where it is a competition to see how high a person can get their feet above the ground. Jeremy Bayliss and Graeme Smith of the Cri Bar and Grill in Napier, New Zealand, started it after seeing American astronauts sticking to walls during space flights. They created their own equipment for the "human fly" contests, and sold it to several others in New Zealand. By 1992, wall-jumping was practiced in dozens of New Zealand bars and was said to be one of the favorite bar activities there at the time.
The game had moved to the U.S. after Sports Illustrated published a story on it in 1991. Adam Powers and Stephen Wastell of the Perfect Tommy's bar in New York city read of the game, and soon became the United States distributor of Human Bar Fly equipment.
In popular culture
1969–1972 - Velcro brand fasteners were used on the suits, sample collection bags, and lunar vehicles during all Apollo program missions to the Moon. The investigation board for the Apollo 1 incident cited the prevalence of Velcro—almost —near the ignition source as part of the combustible material near the fire in the command module, which caused the deaths of astronauts Gus Grissom, Ed White, and Roger Chaffee.
1966–1969 In Star Trek: The Original Series, Velcro was used instead of belts or holsters as a space-age way to attach phasers and communicators to crew uniforms.
1984 - David Letterman wears a suit made of hook-and-loop and jumps from a trampoline into a wall covered in the product during an interview with Velcro Companies' USA director of industrial sales.
1996 - In the John Frankenheimer film The Island of Dr. Moreau, Moreau's assistant jokingly claims that the doctor won his Nobel Prize for inventing Velcro.
1997 - The fastener has become part of a recurring joke in various media in which it is claimed that modern humans would be unable to invent it, and that it is in fact a form of advanced technology. For example, K claims in Men in Black that Velcro was originally alien technology,
2002 - The Star Trek: Enterprise episode "Carbon Creek" portrays Velcro as being introduced to human society by Vulcans in 1957. One of the Vulcans in the episode is named "Mestral", after the fastener's actual inventor and founder of the brand.
2004 - One of the characters in the film Garden State made a vast fortune from inventing "silent Velcro".
2016 - As an April Fools' Day joke Lexus introduced "Variable Load Coupling Rear Orientation (V-LCRO)" seats, technology that attaches the driver to the seat with Velcro Brand product to allow for more aggressive turns.
See also
Metaklett
References
External links
Textile closures
Fasteners
Swiss inventions | Hook-and-loop fastener | [
"Engineering"
] | 3,554 | [
"Construction",
"Fasteners"
] |
42,911,474 | https://en.wikipedia.org/wiki/Centre%20for%20Sustainability%20and%20Environmental%20Management%20/%20Brunel%20Management%20Programme | The major activities of the Centre for Sustainability and Environmental Management / Brunel Management Programme (CSEM-BMP) are research, consultancy and post-graduate and seminar level education and training. All its activities are aimed at supporting the development of sustainable businesses in the UK and world-wide.
Professor Ross King is Joint Programme Director of CSEM-BMP.
History
CSEM-BMP was founded as the Brunel Environmental Management Programme (BEMP) or the Environmental Management Centre (EMC) within the Brunel Management Programme (BMP) by Ken Knight and Ross King. The EMC later became the Centre for Sustainable and Environmental Management (CSEM), then the Centre for Sustainability and Environmental Management (CSEM) and is now known as CSEM-BMP.
Through the EMC, BMP offered the first and largest broad senior level environmental management programme in Europe.
By 1993 the BEMP had organised 39 short courses, with 380 attendees.
The EMC established the first modular master's degree in Environmental Management in 1993 / 1994.
By the end of 1994 about 1000 managers had attended EMC courses.
From that time the focus of the EMC was on both identifying and disseminating the requisite management knowledge and theory so that directors and managers could lead their organizations towards economically advantageous environmental and social sustainability.
Work has been done by CSEM-BMP on management development provision for each business function (such as purchasing, operations, marketing, and logistics) rethinking the function from a sustainability perspective, so that each function can relieve overburdened environmental specialists.
Sustainability Leadership Programme
In 2010 CSEM-BMP offered the Sustainability Leadership Programme (SLP) of Integrated Sustainability Management for Business. The programme offered by CSEM-BMP is for developing leadership and management. The programme is designed against the curriculum for an MBA, is based on sustainability principles and designed to meet the needs of each business function, process and level. It is designed for the needs of senior functional managers, those wishing to move into these positions, and those that need to communicate to such people. Being modular individual courses can be taken or combined in any combination including as a Masters programme.
Each module on the SLP comprise one week of study and an eight-week work-based assignment. Assignments on the SLP are generally to apply the material from the module and further reading to participant's own organisation in the form of a board level paper. Additional support is provided on the SLP in the form of tutorials and self organised learning groups.
The SLP highlights that any environmental or sustainability initiative requires a sound business case. It examines current management understanding and what needs to be done differently or better to operate with environmental and social limits. Core modules on the SLP help participants 'sit behind a chair' at the boardroom table, providing the ability to talk to board members and act as change agents in their organisation.
SLP contributors include 50+ associates. These associates are among the leaders in their respective fields.
Commendations
Philip Sadler, CBE, former CEO of Ashridge Business School, Patron of the Tomorrowís Company Project has stated: ìCSEMís Sustainability Management Programme has long roots and huge experience and may be the Executive MBA of the future.î
In 2009 a programme review panel commended CSEM on:
"a leading-edge programme providing what organisations need ...;
the programme's pioneering nature giving learners business currency and practical information transfer;
the design principles of the programme, the focus of the course design and the appropriate module content meeting students' need in creative ways;
the tailoring of assignments to students' needs and those of their organisations;
the learning set approach and the support it provides to students;
the calibre of the tutors and the exceptional range of practitioner input."
References
External links
Official Website
Management education
Sustainability organizations
Environmental education | Centre for Sustainability and Environmental Management / Brunel Management Programme | [
"Environmental_science"
] | 783 | [
"Environmental education",
"Environmental social science"
] |
42,911,578 | https://en.wikipedia.org/wiki/Acyldepsipeptide%20antibiotics | Acyldepsipeptide or cyclic acyldepsipeptide (ADEP) is a class of potential antibiotics first isolated from bacteria and act by deregulating the ClpP protease. Natural ADEPs were originally found as products of aerobic fermentation in Streptomyces hawaiiensis, A54556A and B, and in the culture broth of Streptomyces species, enopeptin A and B. ADEPs are of great interest in drug development due to their antibiotic properties and thus are being modified in attempt to achieve greater antimicrobial activity.
The potential role of ADEPs in combating antibiotic drug resistance is postulated due to their novel mode of action that other antibiotics are not known to use, activation of casein lytic protease (ClpP) which is an important bacterial protease. Most antibiotics work through inhibitory processes to establish cell death, while ADEPs actually work through activation of the protease to cause uncontrolled protein degradation, inhibition of cell division, and subsequent cell death. They largely affect Gram-positive bacteria and could be of great use to target antibiotic resistant microbes such as methicillin-resistant Staphylococcus aureus (MRSA), penicillin-resistant Streptococcus pneumoniae (PRSP), Mycobacterium tuberculosis, and others. Despite the potential use of ADEP, possible resistance has been examined in certain species.
Mechanism
ADEP antibiotics can be used to defeat resistant bacterial infections. They bind to ClpP and allow the protease to degrade proteins without the help of an ATPase. ADEP4/ClpP complexes target primarily newly formed proteins, and FtsZ which allows cell division. ClpP active form is a tetradecamer composed of two heptamers to which 14 ADEPs bind to.
ADEPs bind in the cavities formed by two ClpP monomers. Their binding site is composed of hydrophobic residues and corresponds to the binding sites of ClpP ATPases. Upon binding, a series of secondary structures shifts occur from the outer region to the center of ClpP. This puts the flexible N-terminal β-loop, into a disordered state. The β-loops normally form a gate above the proteolytic channel and prevent proteins from randomly passing through. They are critical for ClpP interaction with its substrate and ATPases. When ADEP binds, the β-loops shift outward and this is accompanied by the shifts of two α-helices (α1 and α2), four β-strands (β1, β2, β3 and β5) and other loops which lead to the opening of the ClpP pore. In summary, ADEP4 deregulates ClpP function and changes it from a closed state to an open one. At this point its specific proteolytic activity becomes a less controlled process, with the destruction of proteins that are around in the targeted cell.
The peptidase ClpP is highly conserved throughout organisms and is tightly regulated. Without activation, ClpP in normal conditions can degrade short peptides that freely diffuse into its inner degradation chamber. Clp-family proteins are ATP-dependent proteases which play a crucial role in the cell function by degrading misfolded proteins. ClpP is a monomer on its own but oligomerizes into tetradecamers when bound to ATPases. It needs an ATPase to identify, unfold, and transfer targeted big proteins into its proteolytic channel. In fact, ClpP on its own can only degrade peptides that are up to six amino acids long.
ADEP binding induces ClpP proteolytic activation that leads to the proteins degradation in the cell, especially nascent proteins and the Ftsz protein which is an important protein in cell division. This potentially leads to cell death and is the reason why ADEP is a promising technique for drug development.
For folded proteins, unfolded proteins, and long peptides, ClpP must be activated by a protein in the family of ATPase associated with diverse cellular activities (AAA proteins), such as ClpA, ClpX, or ClpC. These chaperone proteins are responsible for hydrolyzing ATP to ADP, harnessing the energy, and then taking folded proteins and unfolding them. Next, Clp-ATPases slip the unfolded proteins into the degradation chamber within ClpP, allowing for processive degradation of the substrate. This process is tightly regulated with the hydrolysis of ATP to prevent uncontrolled protein or peptide degradation that would be harmful to the cell.
In contrast, ADEP activates ClpP without the need for ATP hydrolysis, causing degradation of unfolded proteins and peptides within the cell at uncontrolled rates. ADEPs are thought to bind slightly cooperatively on the surface of each ClpP ring in its hydrophobic pockets and have allosteric effects in activation of ClpP. This binding initiates ClpP to undergo a conformational change such that its N-terminal region opens up its axial pore to allow for partial degradation of products, as compared to progressive degradation with ClpA. ADEP activation of ClpP does not allow for folded protein degradation, but even with unfolded protein and peptide degradation, ADEP still causes bacterial cell death.
Research has shown that ADEP-activated ClpP targets cell division rather than metabolic processes. ADEP appears to initiate ClpP to preferably degrade FtsZ, an important bacterial protein involved in septum formation that is necessary for bacterial cell division. As a result, Gram-positive bacteria treated with ADEPs form long filaments before cell death.
Advantages
When bacteria are exposed to antibiotics they can become resistant or tolerant to the antibiotic. ADEPs have a great potential for clinical application due to their high antibacterial activity against Gram-positive pathogens such as Staphylococcus aureus, and other pathogens that are found in biofilms and chronic infections. Their effectiveness increases when combined with different antibiotics such as ciprofloxacin, linezolid, vancomycin or rifampicin. Additional studies should focus more on the toxicity of ADEPs and their implementation for clinical use.
Applications
After the dysregulation of bacterial proteolytic machinery by a new class of antibiotics was published in the Journal Nature, many scientists started to study this antibiotic. Most of the experiments are focused on how the ADEPs/ClpP complex work, and the functional difference between ADEP and its synthetic congeners.
In 2011, P. Sass and co-workers performed a research focusing in the interaction and function of ADEPs and ClpP. They induced ADEP into Bacillus subtilis, Staphylococcus aureus and Streptococcus pneumoniae to identify how ADEP leads to the death of bacteria. The results demonstrated that ADEP is perturbing bacterial cell division. To identify the reason why ADEP inhibited cell division, researchers monitored septum formation and nucleoid segregation in ADEP B. subtilis and ADEP S. aureus. The S. aureus and B. subtilis samples gave equivalent results. This part showed the importance of wild type of ClpP and inhibition of septum formation is by direct interference of ADEP with the cell division components. Localization studies by GFP-labeled cell divisions proteins demonstrated that ADEP causes delocalization of Ftsz and inhibition of Z-Ring assembly in both species. The impact of ADEP in ∆clpX mutant indicated that ADEP is affecting cell division and that it also inhibits Z-ring assembly. Finally researchers repeat the experiment with ∆ClpP mutant to confirm that the presence of ADEP decreases abundance of FtsZ through ClpP degradation.
In 2013, scientists at Northeastern University performed an experiment focused on how ADEP 4/ClpP works. The experimental results showed the efficiency of ADEP4 when it is combined with other antibiotics. Researchers monitored the amount of trypic peptides, and found out that ADEP4/ClpP induces peptide degradation in a biofilm system. By using Mueller-Hinton broth they demonstrated that ADEP 4 was more effective than other antibiotics such as rifampicin or vancomycin. However, they observed the same trends where ADEP4 combined to rifampicin is more effective and actually eradicates all stationary phases. The in vitro results showed the efficiency of ADEP 4 in mice infected with 4 different strains S. aureus, the laboratory strain SA113, and clinical isolates USA300, UAMS-1 and strain 37.
Chemistry
ADEPs are naturally occurring antibiotics. Certain bacteria produce them as defense mechanism in antagonist bacterial interactions. For instance, Streptomyces species produce them as secondary metabolites.
There are 6 forms of acyl depsipeptides that are distinguishable by their chemical structure and function. ADEPs generally differ by one or two functional groups that give some of them more flexibility, and stability. Their chemical structures are derived from ADEP 1 and are slightly different from one another. For instance, the only difference between ADEP 2 and ADEP 3 is the conformation of the difluorophenylalanine side chain. ADEP 2 has an S configuarion while ADEP 3 has an R configuarion.
Molecular modification
In order to develop a useful antibiotic, ADEP continues to be modified for greater antimicrobial activity and stability. By restricting components of ADEP to decrease the molecule's flexibility, binding was enhanced and antimicrobial activity significantly increased. Specific amino acids essential to the peptidolactone core of ADEP were altered and restricted, causing stabilization of ADEP in a bioactive conformation. In fact, the conformational restrictions of ADEP resulted in its ability to activate ClpP increasing seven-fold and its antimicrobial activity 1200-fold. Research on altering ADEP molecules continues in attempt to construct a new antibiotic for public use.
References
Further reading
Molecular description of ADEP1
Antibiotics | Acyldepsipeptide antibiotics | [
"Biology"
] | 2,112 | [
"Antibiotics",
"Biocides",
"Biotechnology products"
] |
42,911,827 | https://en.wikipedia.org/wiki/Talkomatic | Talkomatic is an online chat system that facilitates real-time text communication among a small group of people. Each participant in Talkomatic has their own section of the screen, broadcasting messages letter-by-letter as they are typed. This interaction was dissimilar from present-day chat systems and was based upon work done in 1973 at the University of Illinois on the PLATO system by Doug Brown and David R. Woolley.
History
The original Talkomatic was the first multi-user online chat system, with the possible exception of the Party Line function of the Emergency Management Information Systems And Reference Index (EMISARI) system, created for the US Office of Emergency Preparedness by Murray Turoff in 1971. Talkomatic was created by Doug Brown and David R. Woolley in 1973 on the PLATO System at the University of Illinois. It offered six channels (the analog of a "room"), which could each hold up to five participants. Along with PLATO Notes and a wide variety of games, Talkomatic was one of the features of PLATO that gave rise to a large online community that persisted into the mid 1980s.
Ray Ozzie's smartphone app, Talko (launched in September 2014 and acquired, and dissolved by Microsoft in 2016), was named after Talkomatic, which Ozzie experienced while working on the PLATO System in the 1970s.
Web version
On March 11, 2014, Brown and Woolley released a new version of Talkomatic designed for the web. Intended to be a reinterpretation of its 1970s namesake, it is conceptually similar to the original system, but limitations imposed by the resource constraints of the time (such as the maximum room count) have been lifted. However, as of March 14, 2024, the web is now unavailable for public use due to technical reasons and the action of some users that were considered disrespectful.
But, as of June 2024, Talkomatic is back up and bans people who do disrespectful actions.
Revival of original concepts
Features of the original work included public, private and semi-private spaces which enabled five concurrent "chatters" to communicate in accordance with their privacy needs.
By the end of 2017, Talkomatic was in its third version and supported the original's features of Public and Private rooms but work on the final feature, Semi-Private rooms had not been implemented.
On March 11, 2018, Version 4 was released, completing the features of the original version with some enhancements in support of the greater variety of modern-day browsers and display resolutions. With this final addition, a feature was added to address the problems arising from truly anonymous access.
On March 4, 2024, a well-known YouTuber under the online alias of yikes attempted to revive a reimagined version of the website Talkomatic by advertising it on TikTok, Reddit, YouTube and Instagram. However, this effort led to the website's shutdown due to the server's inability to handle the increased load. As of June 2024, Talkomatic is back up and running on talkomatic.co because of the community.
Enabling anonymity
The original Talkomatic evolved in the PLATO community which was largely limited by the constraints of requiring credentials used to access the PLATO system. The system recognized different types of users: authors, instructors, students and multiples. These users were managed as "groups" and the owners of those groups provided the administrative oversight necessary if user conduct was deemed inappropriate by others. At the discretion of a group owner, credentials could be suspended or revoked entirely. The most anonymous of the credential types, multiples, could be prevented from accessing the Talkomatic system, thus preventing any type of anonymous access.
Talkomatic (Web version) was designed to be freely available for use by anyone but complete anonymity invited abuse. The Version 4 solution was to implement an in-room voting system for rooms holding three or more participants. Participants who deemed the conduct of another to be inappropriate could "vote-down" the offending user. If a participant's conduct is deemed inappropriate by more than half of the participants, the offending participant is ejected from the room.
In addition to Brown and Woolley's original domain (talko.cc), Ray Ozzie donated three other domains to the conservation efforts. In 2018, Talkomatic was available at talko.cc, talkomatic.com, talkomatic.org, and talkomatic.net.
References
External links
Official website
Internet culture
Online chat
Chat websites
Social media
1973 establishments in Illinois | Talkomatic | [
"Technology"
] | 949 | [
"Computing and society",
"Social media"
] |
42,912,557 | https://en.wikipedia.org/wiki/Future%20of%20Life%20Institute | The Future of Life Institute (FLI) is a nonprofit organization which aims to steer transformative technology towards benefiting life and away from large-scale risks, with a focus on existential risk from advanced artificial intelligence (AI). FLI's work includes grantmaking, educational outreach, and advocacy within the United Nations, United States government, and European Union institutions.
The founders of the Institute include MIT cosmologist Max Tegmark, UCSC cosmologist Anthony Aguirre, and Skype co-founder Jaan Tallinn; among the Institute's advisors is entrepreneur Elon Musk.
Purpose
FLI's stated mission is to steer transformative technology towards benefiting life and away from large-scale risks. FLI's philosophy focuses on the potential risk to humanity from the development of human-level or superintelligent artificial general intelligence (AGI), but also works to mitigate risk from biotechnology, nuclear weapons and global warming.
History
FLI was founded in March 2014 by MIT cosmologist Max Tegmark, Skype co-founder Jaan Tallinn, DeepMind research scientist Viktoriya Krakovna, Tufts University postdoctoral scholar Meia Chita-Tegmark, and UCSC physicist Anthony Aguirre. The Institute's advisors include computer scientists Stuart J. Russell and Francesca Rossi, biologist George Church, cosmologist Saul Perlmutter, astrophysicist Sandra Faber, theoretical physicist Frank Wilczek, entrepreneur Elon Musk, and actors and science communicators Alan Alda and Morgan Freeman (as well as cosmologist Stephen Hawking prior to his death in 2018).
Starting in 2017, FLI has offered an annual "Future of Life Award", with the first awardee being Vasili Arkhipov. The same year, FLI released Slaughterbots, a short arms-control advocacy film. FLI released a sequel in 2021.
In 2018, FLI drafted a letter calling for "laws against lethal autonomous weapons". Signatories included Elon Musk, Demis Hassabis, Shane Legg, and Mustafa Suleyman.
In January 2023, Swedish magazine Expo reported that the FLI had offered a grant of $100,000 to a foundation set up by Nya Dagbladet, a Swedish far-right online newspaper. In response, Tegmark said that the institute had only become aware of Nya Dagbladet's positions during due diligence processes a few months after the grant was initially offered, and that the grant had been immediately revoked.
Open letter on an AI pause
titled "Pause Giant AI Experiments: An Open Letter". This called on major AI developers to agree on a verifiable six-month pause of any systems "more powerful than GPT-4" and to use that time to institute a framework for ensuring safety; or, failing that, for governments to step in with a moratorium. The letter said: "recent months have seen AI labs locked in an out-of-control race to develop and deploy ever more powerful digital minds that no-one - not even their creators - can understand, predict, or reliably control". The letter referred to the possibility of "a profound change in the history of life on Earth" as well as potential risks of AI-generated propaganda, loss of jobs, human obsolescence, and society-wide loss of control.
Prominent signatories of the letter included Elon Musk, Steve Wozniak, Evan Sharp, Chris Larsen, and Gary Marcus; AI lab CEOs Connor Leahy and Emad Mostaque; politician Andrew Yang; deep-learning researcher Yoshua Bengio; and Yuval Noah Harari. Marcus stated "the letter isn't perfect, but the spirit is right." Mostaque stated, "I don't think a six month pause is the best idea or agree with everything but there are some interesting things in that letter." In contrast, Bengio explicitly endorsed the six-month pause in a press conference. Musk predicted that "Leading AGI developers will not heed this warning, but at least it was said." Some signatories, including Musk, said they were motivated by fears of existential risk from artificial general intelligence. Some of the other signatories, such as Marcus, instead said they signed out of concern about risks such as AI-generated propaganda.
The authors of one of the papers cited in FLI's letter, "On the Dangers of Stochastic Parrots: Can Language Models Be Too Big?" including Emily M. Bender, Timnit Gebru, and Margaret Mitchell, criticised the letter. Mitchell said that “by treating a lot of questionable ideas as a given, the letter asserts a set of priorities and a narrative on AI that benefits the supporters of FLI. Ignoring active harms right now is a privilege that some of us don’t have.”
Operations
Advocacy
FLI has actively contributed to policymaking on AI. In October 2023, for example, U.S. Senate majority leader Chuck Schumer invited FLI to share its perspective on AI regulation with selected senators. In Europe, FLI successfully advocated for the inclusion of more general AI systems, such as GPT-4, in the EU's Artificial Intelligence Act.
In military policy, FLI coordinated the support of the scientific community for the Treaty on the Prohibition of Nuclear Weapons. At the UN and elsewhere, the Institute has also advocated for a treaty on autonomous weapons.
Research grants
The FLI research program started in 2015 with an initial donation of $10 million from Elon Musk. In this initial round, a total of $7 million was awarded to 37 research projects. In July 2021, FLI announced that it would launch a new $25 million grant program with funding from the Russian–Canadian programmer Vitalik Buterin.
Conferences
In 2014, the Future of Life Institute held its opening event at MIT: a panel discussion on "The Future of Technology: Benefits and Risks", moderated by Alan Alda. The panelists were synthetic biologist George Church, geneticist Ting Wu, economist Andrew McAfee, physicist and Nobel laureate Frank Wilczek and Skype co-founder Jaan Tallinn.
Since 2015, FLI has organised biannual conferences with the stated purpose of bringing together AI researchers from academia and industry. , the following conferences have taken place:
"The Future of AI: Opportunities and Challenges" conference in Puerto Rico (2015). The stated goal was to identify promising research directions that could help maximize the future benefits of AI. At the conference, FLI circulated an open letter on AI safety which was subsequently signed by Stephen Hawking, Elon Musk, and many artificial intelligence researchers.
The Beneficial AI conference in Asilomar, California (2017), a private gathering of what The New York Times called "heavy hitters of A.I." (including Yann LeCun, Elon Musk, and Nick Bostrom). The institute released a set of principles for responsible AI development that came out of the discussion at the conference, signed by Yoshua Bengio, Yann LeCun, and many other AI researchers. These principles may have influenced the regulation of artificial intelligence and subsequent initiatives, such as the OECD Principles on Artificial Intelligence.
The beneficial AGI conference in Puerto Rico (2019). The stated focus of the meeting was answering long-term questions with the goal of ensuring that artificial general intelligence is beneficial to humanity.
In the media
"The Fight to Define When AI is 'High-Risk'" in Wired.
"Lethal Autonomous Weapons exist; They Must Be Banned" in IEEE Spectrum.
"United States and Allies Protest U.N. Talks to Ban Nuclear Weapons" in The New York Times.
"Is Artificial Intelligence a Threat?" in The Chronicle of Higher Education, including interviews with FLI founders Max Tegmark, Jaan Tallinn and Viktoriya Krakovna.
"But What Would the End of Humanity Mean for Me?", an interview with Max Tegmark on the ideas behind FLI in The Atlantic.
See also
Future of Humanity Institute
Centre for the Study of Existential Risk
Global catastrophic risk
Leverhulme Centre for the Future of Intelligence
Machine Intelligence Research Institute
The Precipice: Existential Risk and the Future of Humanity
References
External links
Futures studies organizations
2014 establishments in Massachusetts
Research institutes established in 2014
Artificial intelligence associations
Transhumanist organizations
Existential risk organizations
Existential risk from artificial general intelligence
Organizations associated with effective altruism
Regulation of artificial intelligence | Future of Life Institute | [
"Technology"
] | 1,762 | [
"Computing and society",
"Existential risk from artificial general intelligence",
"Regulation of artificial intelligence"
] |
42,913,744 | https://en.wikipedia.org/wiki/Interlegis | Intelegis is a program of the Brazilian State, funded by the Inter-American Development Bank (IADB) and administered by the Federal Senate of Brazil. Its mission is to integrate and modernize the Brazilian Legislative Power, in Municipal, State and Federal levels. It started in 1997 in the Brazilian Senate Data Processing organ - Prodasen, born from the PhD project of Armando Roberto Cerchi Nascimento, an official of that body. In 1999 the Brazilian Government signed the contract, establishing a partnership between the IADB and the Brazilian Senate, initiating the Interlegis Program, which was divided into 3 phases: e-Parliament (technology within the parliament), e-Government (process automation and availability of network services for the citizen) and e-democracy (citizen participation in the legislative process).
In practice, Interlegis Program seeks to improve communication and information flow among legislators, increase the efficiency and competence of the Legislative Houses and promote citizen participation in the legislative processes, preparing the Brazilian parliaments for participatory democracy or e-democracy. It operates based on four pillars: communication, information, training and technology.
In the technology area, Interlegis Program develops systems for the parliaments, released them as free and open source software under the GPL license and it are developed with the participation of user communities and concerned citizens, supported by Colab environment. The main systems are:
SAPL - Legislative Process Support System - aimed at automation of electronic legislative process;
Model Portal - a CMS portal is ready to use and customized for a Legislative Houses with transparency tools, law on access to information, public participation, open data, e-democracy, among others.
SAAP - Parliamentary Activity Support System - aimed at automation of offices of parliamentarians;
SPDO - Protocol Document System - aimed at automating the electronic protocol of the Legislative Houses, reducing paper usage;
SAAL - Legislative Administration Support System - aimed at administrative automation of a parliament, as a legislative ERP. Is under development and not yet have a useful version.
The Interlegis was responsible for one of the biggest digital inclusion programs at the beginning of the 21st century, distributing equipment and connecting to the Internet 3398 Brazilian municipalities through the Municipal Councils and Legislative Assemblies, thus creating Interlegis National Network - RNI. Today the technology infrastructure sector of Interlegis also active in hosting products and services developed and provided free of charge by Interlegis to the Brazilian Legislative Houses.
In 2010 Interlegis created the Colab, which is a collaborative environment for the legislative communities of practice, which has Internet tools to encourage participation of concerned citizens, officials and parliamentarians of the Legislative Houses, with the goal of solving the practical parliaments problems, allowing better communication between the participating people and collaborate in various areas of knowledge such as legislative counsel, development of technologies, legislative communication and administration, among others.
In 2013, after the administrative reform of the Brazilian Senate, Interlegis Program, which was previously run by a special secretariat called SINTER, became administrated by the Brazilian Legislative Institute - ILB, supervised by the Brazilian Senate body responsible for the training of legislative servants. At that time, the contract with the IADB regarding the 2nd phase (e-Government) has been extended until the end of 2014, when will occur the renegotiation and redefinition of the continuity of the program to start the 3rd phase (e-democracy).
External links
Interlegis Portal
Colab - Legislative Communities Collaboration Environment
Download and documentation wiki for Interlegis developed software
References
Multiphase Program Supporting Electronic Legislative Development in Brasil (Interlegis II)
Parliamentary Power Integration
Support Multi-Phase Program Electronic Legislative Development
Legislatures
Democracy
E-democracy
E-government by country | Interlegis | [
"Technology"
] | 760 | [
"E-democracy",
"Computing and society"
] |
42,914,369 | https://en.wikipedia.org/wiki/Infrared%20safety | In quantum field theory, and especially asymptotically free quantum field theories, an observable is infrared safe if it does not depend on the low energy/long distance physics of the theory. Such observables can therefore be calculated reliably using perturbative methods and then compared to experiment.
An example of an observable which is infrared safe is the total scattering cross-section for the collision of an electron and a positron to produce hadrons.
See also
Asymptotic freedom
Infrared divergence
Kinoshita–Lee–Nauenberg theorem
References
Quantum field theory
Quantum chromodynamics | Infrared safety | [
"Physics"
] | 131 | [
"Quantum field theory",
"Quantum mechanics",
"Quantum physics stubs"
] |
42,917,948 | https://en.wikipedia.org/wiki/Sulfuric%20acid%20poisoning | Sulfuric acid poisoning refers to ingestion of sulfuric acid, found in lead-acid batteries and some metal cleaners, pool cleaners, drain cleaners and anti-rust products.
Signs and symptoms
Brown to black streak from angle of mouth
Brown to black vomitus
Brown to black stomach wall
Black swollen tongue
White (chalky white) teeth
Blotting paper appearance of stomach mucosa
Ulceration of esophagus (fibrosis and stricture)
Perforation of stomach.
The stomach resembles a black spongy mass on post mortem
Treatment
For superficial injuries, washing (therapeutic irrigation) is important. Emergency treatments include protecting the airway, which might involve a tracheostomy. Further treatment will vary depending on the severity, but might include investigations to determine the extent of damage (bronchoscopy for the airways and endoscopy for the gastrointestinal tract), followed by treatments including surgery (to debride and repair) and intravenous fluids.
Gastric lavage is contraindicated in corrosive acid poisoning like sulfuric acid poisoning. Bicarbonate is also contraindicated as it liberates carbon dioxide which can cause gastric dilatation leading to rupture of stomach, leading to severe abominal damage or death.
Society and culture
Vitriolage is the act of throwing sulfuric acid or other corrosive acids on somebody's face.
References
External links
Sulphuric acid: Toxicological overview
Sulfuric acid poisoning on Penn Medicine
Sulfuric acid poisoning on Medline Plus
Toxic effects of substances chiefly nonmedicinal as to source
Chemical weapons attacks | Sulfuric acid poisoning | [
"Chemistry",
"Environmental_science"
] | 338 | [
"Toxic effects of substances chiefly nonmedicinal as to source",
"Toxicology",
"Chemical weapons attacks",
"Chemical weapons"
] |
64,296,653 | https://en.wikipedia.org/wiki/Ent-Estradiol | ent-Estradiol (''ent''-E2), or 1-estradiol (1-E2), is an estrogen and the 1-enantiomorph of estradiol. It is a so-called "short-acting" or "impeded" estrogen, similarly to estriol, 17α-estradiol, and dimethylstilbestrol.
References
Abandoned drugs
Secondary alcohols
Estranes
Estrogens
Hydroxyarenes | Ent-Estradiol | [
"Chemistry"
] | 108 | [
"Drug safety",
"Abandoned drugs"
] |
64,298,110 | https://en.wikipedia.org/wiki/Oreomylodon | Oreomylodon is an extinct genus of ground sloth in the family Mylodontidae, endemic to Ecuador during the Pleistocene. The only species, O. wegneri, was long considered to be either a species or subgenus of Glossotherium (as G. wegneri) or a junior synonym of Glossotherium robustum, but studies of its cranial anatomy published in 2019 have supported Oreomylodon as a valid genus, and suggested it is more closely related to Paramylodon. However, a subsequent analysis published in 2020 again sunk Oreomylodon wegneri into Glossotherium, as a distinct species. It shows adaptations to living in a high-altitude habitat, and its fossils have frequently been unearthed in the Interandean Valles of Ecuador, at elevations of between 2,450 and 3,100 meters.
References
Prehistoric sloths
Prehistoric placental genera
Pleistocene xenarthrans
Pleistocene mammals of South America
Lujanian
Fossils of Ecuador
Fossil taxa described in 1949
Nomina dubia | Oreomylodon | [
"Biology"
] | 212 | [
"Biological hypotheses",
"Nomina dubia",
"Controversial taxa"
] |
64,298,954 | https://en.wikipedia.org/wiki/RNP%20world | The RNP world is a hypothesized intermediate period in the origin of life characterized by the existence of ribonucleoproteins. The period followed the hypothesized RNA world and ended with the formation of DNA and contemporary proteins. In the RNP world, RNA molecules began to synthesize peptides. These would eventually become proteins which have since assumed most of the diverse functions RNA performed previously. This transition paved the way for DNA to replace RNA as the primary store of genetic information, leading to life as we know it.
Principle of concept
Thomas Cech, in 2009, proposed the existence of the RNP world after his observation of apparent differences in the composition of catalysts in the two most fundamental processes that maintain and express genetic systems. For DNA, the maintenance, replication, and transcription processes are accomplished purely by protein polymerases. However, the mRNA processes of gene expression via splicing and protein synthesis are catalyzed by RNP complexes (the spliceosome and ribosome).
This difference between protein and ribonucleoprotein catalysts can be explained by extending the RNA world theory. The older RNA molecules were originally self-catalyzed through ribozymes, which evolved the assistance of proteins to form RNP. Thereafter, the newer DNA molecule used only the more efficient protein processes from the start. Thus, our current DNA world could have resulted from the gradual replacement of RNA catalysis machines with proteins. In this view, ribonucleoproteins and nucleotide-based cofactors are remnants of an intermediary era, the RNP world.
See also
First universal common ancestor
References
Ribonucleoproteins
RNA
DNA
Peptides
Proteins
Origin of life | RNP world | [
"Chemistry",
"Biology"
] | 363 | [
"Biomolecules by chemical classification",
"Origin of life",
"Molecular biology",
"Biological hypotheses",
"Proteins",
"Peptides"
] |
64,299,662 | https://en.wikipedia.org/wiki/C16H18O2 | {{DISPLAYTITLE:C16H18O2}}
The molecular formula C16H18O2 (molar mass: 242.31 g/mol, exact mass: 242.1307 u) may refer to:
rac-Butestrol
meso-Butestrol
Molecular formulas | C16H18O2 | [
"Physics",
"Chemistry"
] | 65 | [
"Molecules",
"Set index articles on molecular formulas",
"Isomerism",
"Molecular formulas",
"Matter"
] |
64,304,060 | https://en.wikipedia.org/wiki/Vector%20bornology | In mathematics, especially functional analysis, a bornology on a vector space over a field where has a bornology ℬ, is called a vector bornology if makes the vector space operations into bounded maps.
Definitions
Prerequisits
A on a set is a collection of subsets of that satisfy all the following conditions:
covers that is,
is stable under inclusions; that is, if and then
is stable under finite unions; that is, if then
Elements of the collection are called or simply if is understood.
The pair is called a or a .
A or of a bornology is a subset of such that each element of is a subset of some element of Given a collection of subsets of the smallest bornology containing is called the bornology generated by
If and are bornological sets then their on is the bornology having as a base the collection of all sets of the form where and
A subset of is bounded in the product bornology if and only if its image under the canonical projections onto and are both bounded.
If and are bornological sets then a function is said to be a or a (with respect to these bornologies) if it maps -bounded subsets of to -bounded subsets of that is, if
If in addition is a bijection and is also bounded then is called a .
Vector bornology
Let be a vector space over a field where has a bornology
A bornology on is called a if it is stable under vector addition, scalar multiplication, and the formation of balanced hulls (i.e. if the sum of two bounded sets is bounded, etc.).
If is a vector space and is a bornology on then the following are equivalent:
is a vector bornology
Finite sums and balanced hulls of -bounded sets are -bounded
The scalar multiplication map defined by and the addition map defined by are both bounded when their domains carry their product bornologies (i.e. they map bounded subsets to bounded subsets)
A vector bornology is called a if it is stable under the formation of convex hulls (i.e. the convex hull of a bounded set is bounded) then
And a vector bornology is called if the only bounded vector subspace of is the 0-dimensional trivial space
Usually, is either the real or complex numbers, in which case a vector bornology on will be called a if has a base consisting of convex sets.
Characterizations
Suppose that is a vector space over the field of real or complex numbers and is a bornology on
Then the following are equivalent:
is a vector bornology
addition and scalar multiplication are bounded maps
the balanced hull of every element of is an element of and the sum of any two elements of is again an element of
Bornology on a topological vector space
If is a topological vector space then the set of all bounded subsets of from a vector bornology on called the , the , or simply the of and is referred to as .
In any locally convex topological vector space the set of all closed bounded disks form a base for the usual bornology of
Unless indicated otherwise, it is always assumed that the real or complex numbers are endowed with the usual bornology.
Topology induced by a vector bornology
Suppose that is a vector space over the field of real or complex numbers and is a vector bornology on
Let denote all those subsets of that are convex, balanced, and bornivorous.
Then forms a neighborhood basis at the origin for a locally convex topological vector space topology.
Examples
Locally convex space of bounded functions
Let be the real or complex numbers (endowed with their usual bornologies), let be a bounded structure, and let denote the vector space of all locally bounded -valued maps on
For every let for all where this defines a seminorm on
The locally convex topological vector space topology on defined by the family of seminorms is called the .
This topology makes into a complete space.
Bornology of equicontinuity
Let be a topological space, be the real or complex numbers, and let denote the vector space of all continuous -valued maps on
The set of all equicontinuous subsets of forms a vector bornology on
See also
Bornivorous set
Bornological space
Bornology
Space of linear maps
Ultrabornological space
Citations
Bibliography
Topological vector spaces | Vector bornology | [
"Mathematics"
] | 864 | [
"Topological vector spaces",
"Vector spaces",
"Space (mathematics)"
] |
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