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60,671,548 | https://en.wikipedia.org/wiki/C7orf26 | c7orf26 (Chromosome 7, Open Reading Frame 26) is a gene in humans that encodes a protein known as c7orf26 (uncharacterized protein c7orf26). Based on properties of c7orf26 and its conservation over a long period of time, its suggested function is targeted for the cytoplasm and it is predicted to play a role in regulating transcription.
Gene
Background
Chromosome 7 is one of the 23 pairs of chromosomes in the human body, and spans about 159 million base pairs and represents about 5-5.5% of the total DNA in cells. Changes to the structure of chromosome 7 can result in a number of genetic abnormalities, including Williams Syndrome which causes structural and cosmetic changes to the human body, ultimately resulting in a shorter lifespan. There are hundreds of known open reading frames (ORF) along the domain of chromosome 7, however there is not much known about the 26th reading frame, which is of considerable interest.
Currently, two isoforms of c7orf26 are known in Homo Sapiens and are referred to as isoforms 1 and 2, respectively.
Location
c7orf26 (accession: NM_024067 / NP_076972; alias: MGC-2178) is located on the long arm of chromosome 7 (7p22.1), starting at 6590021 and ending at 6608726. The c7orf26 gene spans 2178 base pairs and is orientated on the + strand. The coding region is made up of a protein sequence measuring 449 amino acids long. It is divided into 6 transcripts containing a total of 24 exons on the forward strand and has 5952 unique Single Nucleotide Polymorphisms (SNPs).
Gene neighborhood
Genes ZDHHC4, ZNF853 and ZNF316 neighbor c7orf26 on chromosome 7. Gene ZDHHC4 is a zinc-finger protein involved with cytochrome-c oxidase activity and protein-cysteine S-palmitoyltransferase activity and has overlapping regions with c7orf26. Gene GRID2IP lies upstream by >2000 bp of c7orf26, and is heavily involved with in synaptogenesis and synaptic plasticity.
Expression
c7orf26 is highly expressed in lymphatic, reproductive, and nervous tissue. These include the brain (frontal and occipital cortex), thymus glands, salivary glands, endometrium, cervix, and prostate. It is intermediately expressed in the lungs.
Homology
Paralogs
No paralogs of c7orf26 have been found in the human genome, however, six unique isoforms have been identified. They are c7orf26 isoform (X1, X2, X3, X4) and isoform 2 (two sub-isoforms identified).
Orthologs
Below is a table of a variety of orthologs of the human c7orf26. The table include closely, intermediately and distantly related orthologs. Orthologs of the human protein c7orf26 are listed above in descending order of the date of divergence. c7orf26 is highly conserved throughout all orthologs, this is demonstrated with a 65% identity in the least similar ortholog. c7orf26 has evolved slowly and evenly over time.
Phylogeny
Below is a phylogenetic tree showing the evolutionary history of c7orf26 and its nearest orthologs.
Protein
General properties
The molecular weight of c7orf26 is 50 kilodaltons. The isoelectric point is 7.61. The protein sequence is uniquely rich for leucine at 15.8% of its composition, this may indicate a leucine-zipper. Further analysis from PSORT indicates that a leucine-zipper region is found at amino acid 318 and lasts until position 340 (22 amino acids long). There are no extremes with regards to acidity and alkalinity. c7orf26 has a positive charge cluster from amino acid 245 – 275 and does not have any negative, or mixed charge clusters.
Composition
An even distribution of amino acids compose c7orf26. The percent composition of each amino acid is fairly consistent throughout the orthologs of the protein. The most distant ortholog displays the most variance in amino acid composition. There is a higher percent composition of tyrosine, histidine and leucine and a lower composition of valine and alanine.
Post-translational modifications
c7orf26 is highly phosphorylated post modified. There are 66 predicted phosphorylated sites according to the NetPhos predictor of phosphorylation sites. There are 4 unique sumoylation sites according to SUMOplot/SUMOsp programs. Sumoylation sites are involved in a number of cellular processes, including nuclear-cytosolic transport, transcriptional regulation and protein stability.
According DAS-TMFilter Server, c7orf26 has zero predicted transmembrane sites or transmembrane protein coding regions, therefore, it can be inferred with certainty that c7orf26 is not a transmembrane protein.
Secondary structure
Using the GOR (Garnier-Osguthorpe-Robson) method, it can be inferred that c7orf26 has unique secondary structure composed of alpha helices, random coil regions and extended strands. Random coil regions are most found in c7orf26, as they constitute 53.23% of the protein, while alpha helices constitute 34.30% and extended strands 12.47%.
Subcellular localization
According to PSORT, c7orf26 is predicted to be localized in the cytoplasm with 70.6% confidence.
Interacting proteins
c7orf26 interacts uniquely with 11 different proteins, according to the Mentha interactome browser. In particular, c7orf26 interacts with the entire family of 'INTS' (Integrator Complex Subunit 1–7). The Integrator Complex associates with the C-terminal domain of RNA polymerase II large subunit. It is involved in the transcription and processing of their transcripts. INTS mediates recruitment of cytoplasmic dynein to the nuclear envelope.
Outside of the INTS gene family, c7orf26 interacts with AK5, HDGF, and ASUN.
Clinical significance
According to Guirato et al. (2018), there may be some evidence that regions on chromosome 7 may be directly linked to a nuclear estrogen receptor (ESR2) that modulates cancer cell proliferation and tumor growth. In another journal article by Fu et al. (2014), there is further indication that regions along chromosome 7, located between open reading frames 20-30, directly correlate to cellular functions of a hepatoma-derived growth factor (HDGF), another way of expressing normal function in tumorigenesis.
References
Further reading
Chromosomes
Genes on human chromosome 7
Proteins | C7orf26 | [
"Chemistry"
] | 1,459 | [
"Biomolecules by chemical classification",
"Proteins",
"Molecular biology"
] |
60,671,566 | https://en.wikipedia.org/wiki/C1orf167 | Chromosome 1 open reading frame (C1orf167) is a protein which in humans is encoded by the C1orf167 gene. The NCBI accession number is NP_001010881. The protein is 1468 amino acids in length with a molecular weight of 162.42 kDa. The mRNA sequence was found to be 4689 base pairs in length.
Gene
Locus
It can be located on chromosome 1 at position 1p36.22 on the plus strand and spans from positions 11,824,457 to 1,849,503.
Aliases
C1orf167 has one known alias with the name Chromosome 1 Open Reading Frame 167.
Number of Exons
There are 26 exons associated with the protein.
mRNA
Alternative Splicing
A splice region that is conserved in primate orthologs of the C1orf167 mRNA was located between exon 1 and exon 2.
Known mRNA Isoforms
The mRNA sequence has 8 known splice isoforms as determined by the conserved domains. The isoforms span the regions 426-863, 981-1418, 954-1391, 999-1329, 999-1400, 999-1436, 999-1404. and 999-1463 of the mRNA sequence.
Protein
Known Protein Isoforms
Alternative splicing produces two known isoforms of the human protein. They are XP_006711141.1 which is 1489aa in length and XP_003307860.2 which is 713aa in length.
Composition
The protein has an isoelectric point (pI) of 11. The predicted molecular weight (mW) is 160kDa for the human protein, but ranges from 140-180kDa for more distant orthologs. Compositional analysis revealed the most abundant amino acid to be Alanine (A) at 12.4% of the total protein. The analysis also revealed C1orf167 protein to be rich in Tryptophan (W) and deficient in Tyrosine (Y) and Isoleucine (I).
Subcellular Localization
C1orf167 is predicted to be localized to the cell nucleus.
Post-Translational Modifications
C1orf167 is predicted to undergo phosphorylation, O-Glycosylation, SUMOylation, glycation, and cleavage by staphylococcal peptidase I (Q105, Q321) and Glutamyl endopeptidase (Q1101).
Table 1. Post-Translational Modifications determined for C1orf167.
*GPS, NetPhos results indicated hyper-phosphorylation of C1orf167 in H. sapiens and five of its orthologs.
Domain and Motifs by Homology
One domain of unknown function, located from 954aa-1418aa, is 465 amino acids in length.
Secondary Structure
C1orf167 was determined to be rich in alpha helices. No notable regions of beta pleated sheets or coils were predicted. In particular, high confidence was indicated for 42 alpha helices with the longest alpha helix region spanning from residues 450aa to 1182aa. This long alpha helix region includes a significant portion of the conserved DUF which spans 954aa-1418aa.
Tertiary Structure
The best-aligned structural analog, generated by I-TASSER, of C1orf167 had a confidence (c-score) score of -0.68 given a range of [-5,2] with higher values indicating a higher confidence. Per Swiss Model, two monomers are predicted to form an alpha helix. Both of the helices are aligned facing outwards with hydrophobic amino acids such as glutamic acid (E) on the interior and asparagine (R), Serine (and lysine (K) on the exterior. Asparagine residues may serve as an important oligosaccharide binding site.
Expression
C1orf167 has high expression in the larynx, blood, placenta, testis and prostate, with the highest expression found in the testis. The promoter GXP_5109290 spans 1507 base pairs on chromosome 1. GXP_5109290 was found to be conserved in the bonobo (Pan Paniscus), gorilla (Gorilla Gorilla Gorilla), mouse (Mus musculus), chimp (Pan Troglodytes), and rhesus monkey (Macaca mulata).
Protein Interactions
There were 10 interactions identified by STRING.
Homology
Paralogs
No known paralogs or paralogous domains were identified for C1orf167.
Orthologs
Using NCBI BLAST, orthologs of C1orf167 were determined. No orthologs could be found in single-celled organisms, or fungi whose genomes have been sequenced. In terms of multi-cellular organisms, orthologs were found in mammals, aves, reptiles, and cartilaginous fishes. The table below shows a representative sample of 20 of the orthologs for C1orf167. The table is organized based on the time of divergence from humans in millions of years (MYA) and then by sequence similarity.
Table 2. This table shows the divergence timeline of the C1orf167 orthologs. It is sorted by date of divergence, color according to taxonomic group or class and then by sequence similarity.
Function
At this time the function of C1orf167 is uncharacterized.
Clinical Significance
Pathology
According to the EST profile for breakdown by healthy state, the expression levels of C1orf167 were higher than healthy cells for leukemia, head, neck and lung cancers. Based on the results from NCBI GeoProfiles, C1orf167 was found to have increased expression on dendritic cells for patients experiencing Chlamydia pneumoniae infections. Increased expression of C1orf167 was also indicated for Human Pulmonary Tuberculosis tissues given the presence of caseous tuberculosis granulomas in the lungs when compared to normal lung tissues.
References
Proteins
Genes on human chromosome 1 | C1orf167 | [
"Chemistry"
] | 1,274 | [
"Biomolecules by chemical classification",
"Proteins",
"Molecular biology"
] |
60,671,698 | https://en.wikipedia.org/wiki/Hematology%20analyzer | Hematology analyzers (also spelled haematology analysers in British English) are used to count and identify blood cells at high speed with accuracy. During the 1950s, laboratory technicians counted each individual blood cell underneath a microscope. Tedious and inconsistent, this was replaced with the first, very basic hematology analyzer, engineered by Wallace H. Coulter. The early hematology analyzers relied on Coulter's principle (see Coulter counter). However, they have evolved to encompass numerous techniques.
Uses
Hematology analyzers are used to conduct a complete blood count (CBC), which is usually the first test requested by physicians to determine a patient's general health status. A complete blood count includes red blood cell (RBC), white blood cell (WBC), hemoglobin, and platelet counts, as well as hematocrit levels. Other analyses include:
RBC distribution width
Mean corpuscular volume
Mean corpuscular hemoglobin
Mean corpuscular hemoglobin concentrations
WBC differential count in percentage and absolute value
Platelet distribution width
Platelet mean volume
Large platelet cell ratio
Platelet criteria
Techniques
Flow cytometry
Spectrophotometry
Absorption spectroscopy
Transmission Turbidimetry
Electrical impedance (Coulter's principle)
Digital microscopy with AI
Types
3-part differential cell counter
A 3-part differential cell counter uses Coulter's principle to find the size and volume of the cell. The sample is lysed and dissolved into an electrolyte solution in a container, which also holds a smaller container. The smaller container has two pumps running to and from its solution, one creating a vacuum and the other replacing the lost solution. The smaller container has a small hole (an orifice) near the bottom of the container. Coulter's principle is applied through the use of two electrodes. One electrode (the internal electrode) is within the smaller container, and the other (the external electrode) is outside of the smaller container but within the electrolyte/sample solution. As the vacuum draws the sample cells through the orifice, the cell momentarily causes electrical resistance to the current as it passes through the orifice. This resistance is recorded, measured, amplified, and processed which can then be interpreted by the computer into a histogram. The 3-part analyzer is able to differentiate between three types of white blood cells (WBCs): neutrophils, lymphocytes, and monocytes.
5-part differential cell counter
This type of hematology analyzer utilizes both Coulter's principle and flow cytometry to determine the granularity, diameter, and inner complexity of the cells. Using hydrodynamic focusing, the cells are sent through an aperture one cell at a time. During this, a laser is directed at them, and the scattered light is measured at multiple angles. The absorbance is also recorded. The cell can be identified based on the intensity of the scattered light and the level of absorbance. A 5-part cell counter can differentiate all WBC types (neutrophils, lymphocytes, basophils, eosinophils, and monocytes). 5-part analyzers are more expensive than 3-part analyzers, but provide more in-depth information about the sample. Specific jobs, such as allergy testing, require 5-part differential analysis. However, most medical tasks can be completed with the 3-part analyzer.
Components
The hematology analyzer is broken down into five key components:
Power source
Control unit
Sample Reagent Tray
Collecting system
Data storage
Processing system
Producers
These are the major companies that are known to make quality Hematology Analyzers for hospitals and laboratories:
Beckman Coulter
Sysmex Corporation
HORIBA Ltd
Abbott Laboratories
Bio-Rad Laboratories
Siemens AG
Mindray Medical International Limited
Boule Diagnostics AB
Roche Diagnostics
Nihon Kohden Corporation.
Seamaty Technology
References
Hematology
Blood tests | Hematology analyzer | [
"Chemistry"
] | 814 | [
"Blood tests",
"Chemical pathology"
] |
60,671,706 | https://en.wikipedia.org/wiki/Hydrogen-donor%20solvent | A hydrogen-donor solvent is hydrocarbon that transfers hydrogen to hydrogen-poor substrates, such as coal. The hydrogen-poor substrates could be a solute or suspension. The classic hydrogen-donor solvent (or just donor solvent) is tetrahydronaphthalene, which converts to naphthalene by transfer of two equivalents of H2 to the substrate. The enthalpy of hydrogenation of naphthalene is relatively low, which allows the tetrahydronaphthalene to be regenerated in the presence of high pressure H2. Catalysts are often used, such as molybdenum disulfide. Related hydrogen donor solvents or solvent components are dihydrophenanthrene and tetrahydroquinoline.
References
Coal
Synthetic fuel technologies | Hydrogen-donor solvent | [
"Chemistry"
] | 166 | [
"Petroleum technology",
"Synthetic fuel technologies"
] |
60,671,814 | https://en.wikipedia.org/wiki/C16orf78 | Uncharacterized protein C16orf78(NP_653203.1) is a protein that in humans is encoded by the chromosome 16 open reading frame 78 gene.
Gene
The C16orf78 gene(123970) is located at 16q12.1 on the plus strand, spanning 25,609 bp from 49,407,734 to 49,433,342.
mRNA
There is one mRNA transcript (NM_144602.3) and no other known splice isoforms. There are 5 exons, totaling a length of 1068 base pairs.
Protein
Sequence
C16orf78 is 265 amino acids long with a predicted molecular weight of 30.8 kDal and pI of 9.8. It is rich in both methionine and lysine, composed of 6.4% methionine and 13.6% lysine. This methionine richness has been hypothesized to serve as a mitochondrial antioxidant.
Post-Transnational Modifications
There are four verified ubiquitination sites and three verified phosphorylation sites.
Structure
Predictions of C16orf78's secondary structure consist primarily of alpha helices and coiled coils. Phyre2 also predicted C16orf78 is primarily helical, but 253 of 265 amino acids were modeled ab initio so the confidence of the model is low.
Subcellular Localization
C16orf78 is predicted to be localized to the cell nucleus. There is also a predicted bipartite nuclear localization signal.
Expression
C16orf78 has restricted expression toward the testis, with much lower expression in other tissues.
Interaction
C16orf78 has a physical association with DNA/RNA-binding protein KIN17 (NP_036443.1), suggesting C16orf78 may also play a role in DNA repair. C16orf78 was found to be phosphorylated by SRPK1(NP_003128.3) and SPRK2 (AAH68547.1).
Clinical Significance
Deletion of the C16orf78 gene has been identified as a determinant of prostate cancer. A SNP in C16orf78 interacts with a SNP in LMTK2 and is associated with risk of prostate cancer.
Amplification of the C16orf78 gene has been linked to metabolically adaptive cancer cells. A duplication of the C16orf78 gene was associated with at least one case of Rolandic Epilepsy.
Homology
Paralogs
C16orf78 has no known paralogs in humans.
Orthologs
C16orf78 has over 80 orthologs, including animals as distant Ciona intestinalis(XP_002132057.1), which is estimated to have diverged from humans 676 million years ago. C16orf78 has orthologs in many types of mammals, reptiles, bony fish, and even some invertebrates, but has no known orthologs in amphibians or birds. Below is a table with samples of orthologs, with divergence dates from TimeTree and similarity calculated by pairwise sequence alignment.
References
External links
Proteins
Genes on human chromosome 16 | C16orf78 | [
"Chemistry"
] | 690 | [
"Biomolecules by chemical classification",
"Proteins",
"Molecular biology"
] |
60,672,024 | https://en.wikipedia.org/wiki/SMCO3 | Single-pass membrane and coiled-coil domain-containing protein 3 is a protein that is encoded in humans by the SMCO3 gene.
Gene
Aliases
SMCO3 has 2 aliases, C12orf69 and LOC440087.
Location
SMCO3 is located on the negative strand of chromosome 12 (12p12.3) and spans 10,460 base pairs (chr12:14,803,723-14,814,182). It has 2 exons that flank a single intron.
Gene Neighborhood
SMCO3 is flanked by WW domain binding protein 11 (WBP11) and Ecto-ADP-ribosyltransferase 4 (ART4) on the minus strand and overlaps with C12orf60 on the plus strand. There is only a single isoform of this gene.
Expression
SMCO3 is expressed in very low levels in several different human tissues including cervix, connective tissue, eye, lung and prostate. This highest expression of SMCO3 is seen in the kidney, liver and spleen. SMCO3 is also expressed at higher levels in cancers, especially chondrosarcoma and clear-cell renal cell carcinoma. SMCO3 expression is only seen in the fetus and adult and not in the embryoid bodies, blastocysts, infants and juveniles stages of development.
The expression of SMCO3 appears to depend upon the species, with the Mus musculus homolog of SMCO3 expressed at much higher levels in the eye compared to humans.
Promoter
The promoter region of SMCO3 is 1,100 base pairs long and begins 961 base pairs upstream of the 5' UTR with the end of the promoter completely overlapping the first exon.
Variants
There are 2,152 known nucleotide-level variants of which 27 are coding synonymous single nucleotide polymorphisms. The vast majority of single nucleotide polymorphisms (SNPs) occur within the intron with only a quarter occurring translated regions. No SMCO3 variants are known to be associated with any disorder.
mRNA
Splice Variants
The mRNA transcript of SMCO3 is 2,104 base pair long. There are no mRNA variants of SMCO3.
Regulation
The SMCO3 promoter has many transcription factors binding sites including for cartilage homeoprotein 1, cAMP-responsive element binding proteins, PAR/bZIP family and vertebrate TATA binding protein factor.
Protein
General Properties
SMCO3 is 225 amino acid long with a predicted molecular weight of 24.9. It is a slightly basic protein with a predicted isoelectric point of 8.3.
Composition
SMCO3 is comparably enriched in lysine and comparably poor in proline and phenylalanine compared to other human proteins. SMCO3 contains several long, uncharged segments but does not have any significantly charged segments. Despite being a transmembrane protein there are no significantly hydrophobic regions nor any significantly hydrophilic regions.
Domains and Motifs
SMCO3 has a single domain, DUF4344 (aa15:221) which is currently uncharacterised. C12orf60 also contains this domain. It contains a single transmembrane region (aa155-175) and has two coiled-coil regions (aa62-92, aa183-207). The C-terminus of SMCO3 contains a KKXX-like motif suggesting endoplasmic reticulum localisation.
Structure
The secondary structure of SMCO3 consists of several α-helices and a single β-pleated sheet interspersed with disordered coiled coil regions. in Orthologs of SMCO3 similarly show secondary structure dominated by alpha helices. There are no disulfide bridges predicted in the tertiary structure.
Biochemical Function
The function of the SMCO3 protein is currently unknown.
Post-Translational Modifications
The N-terminus of SMCO3 is cleaved, the first methionine residue removed and the N-terminus acetylated to improve stability. Additionally there are several sites that are likely phosphorylated and a single N-linked glycosylation site which is typical in ER integral membrane proteins. Unlike typical ER integral membrane proteins there is no amino-acid signal sequence.
Sub-Cellular Localisation
SMCO3 contains a transmembrane domain (aa155-175). Additionally the KKXX-like motif highly suggest that it is an endoplasmic reticulum integral membrane protein.
Interacting Proteins
Two-hybrid assays have identified that SMCO3 interacts with five proteins: FUS RNA Binding Protein (FUS), mitogen-activated protein kinase 9 (MAPK9), STN1 subunit of CST complex (OBFC1), protein phosphatase 2 catalytic subunit alpha (PPP2CA) and tripartite motif containing 39 (TRIM39). However, it is not known to take part in any pathway although the structure indicates that it takes part in protein-protein interactions. PP2CA, OBFC1, FUS1 and MAPK9 are all either implicated in cancer or have altered expression in cancer which suggests that SMCO3 may be useful as an eQTL for certain cancers.
Clinical Significance
Mutations
Only 3.4% of SNPs were predicted to be deleterious, of which none had any clinical significance.
Disease Associations
GWAS showed no significant associations of SMCO3 with any disease or traits. SMCO3 is not known to be implicated in any disease. SMCO3 is expressed at higher levels in certain cancers, especially chondrosarcoma and clear-cell renal cell carcinoma.
Evolution
Conservation
The amino acid sequence of SMCO3 is highly conserved compared to other human proteins. There is dramatically lower levels of sequence divergence than expected, even compared to proteins known to have low levels of sequence divergence with time.
Homology
SMCO3 in largely conserved in amniotes. Orthologs have been identified in many mammals, reptiles and birds. The closest ortholog is found in Pan troglodytes and has a 99.7% sequence similarity. More distant homologs have also been identified in a select few bony fish but orthologs are not seen in cartilaginous fish, insects or other invertebrates. No paralogs of SMCO3 in humans have been identified.
References
Proteins | SMCO3 | [
"Chemistry"
] | 1,337 | [
"Biomolecules by chemical classification",
"Proteins",
"Molecular biology"
] |
60,672,167 | https://en.wikipedia.org/wiki/TEDC2 | Tubulin epsilon and delta complex 2 (TEDC2), also known as Chromosome 16 open reading frame 59 (C16orf59), is a protein that in humans is encoded by the TEDC2 gene. Its NCBI accession number is NP_079384.2.
Gene
Locus
TEDC2 is found on chromosome 16 at location 16p13.3, or chr16:2,460,080-2,464,963 (spanning 4883 bp) on the plus strand.
Homology and Evolution
Orthologs
TEDC2 appeared between 684-797 million years ago. Its most distant ortholog is found in Branchiostoma floridae, the Florida lancelet, which diverged from other chordates around 684 million years ago. However, the gene arose more recently than 797 million years ago, when protostomes and deuterostomes diverged, as it is not found in any invertebrates. A table showing 20 selected orthologs is below, found with NCBI BLAST.
Paralogs
There are no other members of the TEDC2 gene family, as it has no paralogs in any living organisms.
Expression
Transcription Factors
Conserved predicted transcription factor binding sites found in the 5' region upstream of TEDC2 are WT1, ZKSCAN3 (x2), AREB6, MZF1 (x2), ATF6, ER, and P53. This suggests that these transcription factors in particular, and especially ZKSCAN3 and MZF1 on the basis of multiple conserved binding sites, are crucial in the regulation of TEDC2. ZKSCAN3 is a transcriptional repressor of autophagy, and MZF1 is thought to play a role as a tumor suppressor and regulator of cell proliferation. These conserved MZF1 sites, along with the conserved p53 site, suggest that TEDC2 could play a role in cell proliferation and can therefore impact the genesis and development of cancer.
Localization
TEDC2 is predicted to be localized to the nucleus and may also be present in the cytoplasm, mitochondria, peroxisomes, and extracellular space.
Expression
It is highly expressed in the testis and EBV-transformed lymphocytes. It is also highly expressed in lymph node, fetal liver, early erythroid cell, and B-lymphoblasts. It is also seen at higher levels in both embryonic stem cells and induced pluripotent stem cells than fibroblasts. Finally, relative to other genes, TEDC2 expression significantly decreases in breast cancer cells upon estrogen starvation.
Transcript Variants
The gene has 10 exons. The gene has 13 alternatively spliced transcripts, with 6 coding for a protein, 1 undergoing nonsense-mediated decay, and 6 being retained introns.
Protein
General Features
TEDC2 is encoded by the TEDC2 gene with NCBI accession number NM_025108.3. The protein is 433 amino acids long with a predicted molecular weight of 46.4 kDa. There is an antibody against the protein, but a sample western blot image is not available.
Domains
TEDC2 contains a domain of unknown function, DUF4693, which in humans spans from proteins 148-431, approximately the last two-thirds of the protein.
Secondary Structure
Using online bioinformatics tools, TEDC2 is predicted to have many alpha helices, and it has two well-conserved predicted beta-pleated sheets near the end of the protein.
Tertiary Structure
TEDC2 is predicted to form tertiary structure based on its alpha helices. Many of these predicted alpha helices are highly conserved in orthologs, and one example of predicted tertiary structure generated by I-TASSER is shown to the right.
Post-translational Modifications
TEDC2 has a well conserved predicted O-GlcNAc site at S114 in humans. O-GlcNAcylated proteins are found mostly in the nucleus, sometimes also being found in the cytoplasm, and this is a dynamic modification, frequently being removed and reattached.
TEDC2 also has three conserved, predicted C-mannosylation sites. The function of C-mannosylation is still unclear, but it is the attachment of an alpha-mannose to a tryptophan.
TEDC2 also has many possible phosphorylation sites, including seven that are well-conserved. Phosphorylation is an important means of protein regulation, activation, and inactivation, so it is difficult to determine any specific function from the presence of a serine or threonine that could be phosphorylated.
Interactions
Protein-Protein Interactions
KDM1A, a lysine-specific demethylase, was shown to be physically associated with TEDC2. TEDC2 also interacts with FEZ1, a fasciculation and elongation protein. FEZ1, or fasciculation and elongation protein 1, is necessary for axon growth but is also thought to be involved in transcriptional control.
There is also experimental evidence for TEDC2 interaction with TUBE1 and C14orf80. TUBE1, or Tubulin epsilon 1, is involved with the centrioles during cell division, and the function of C14orf80 is unknown. TEDC2 is also co-expressed with CDC45, or cell division control protein 45, which is required for initiation of chromosomal DNA replication, as well as co-expression with CDT1, a DNA replication licensing factor required for pre-replication assembly.
Function and Clinical Significance
The function of TEDC2 is not yet known with certainty by the scientific community, but its expression profile, predicted transcription factor binding sites, and other protein-protein interactions enable some predictions. TEDC2 is localized in the nucleus and is often expressed in developing tissues such as stem cells as well as differentiated fetal tissue, so it likely plays a role in DNA replication and/or cell division. This also fits with TEDC2's predicted or known protein-protein interactions, as it may interact with proteins involved in cell division (TUBE1, CDC45, CDT1), as well as remain under transcriptional control of tumor suppressors (WT1, MZF1, P53). Additionally, given the presence of an estrogen-response element binding-site, it is possible that TEDC2 plays a role in tumor development when mutated.
References
Proteins | TEDC2 | [
"Chemistry"
] | 1,367 | [
"Biomolecules by chemical classification",
"Proteins",
"Molecular biology"
] |
60,672,279 | https://en.wikipedia.org/wiki/SKIDA1 | Ski/Dach domain-containing protein 1 is a protein that in humans is encoded by the SKIDA1 gene. It is also known as C10orf140 and DLN-1. It has orthologs in vertebrates. It has two domains: the Ski/Sno/Dac domain and a domain of unknown function, DUF4854. It is associated with multiple types of cancer, like leukemia, ovarian cancer, and colon cancer. It's predicted to be a nuclear protein. It may interact with PRC2.
Homologs
Orthologs
SKIDA1 has orthologs in vertebrate species. The species least related to humans with a SKIDA1 ortholog is the lancelet Branchiostoma belcheri. The clades amphibia and chondrichthyes have at least two species with SKIDA1, but SKIDA1 is not found throughout the clades. No orthologs have been found in lungfish or invertebrate species.
Paralogous Domains
SKIDA1 shares the Ski/Sno/Dac domain with Ski oncogene (Ski), Ski-like protein (Sno), and dachshund (Dac). It shares DUF4584 with Elongin BC Polycomb Repressive Complex 2 associated Protein (EPOP).
Structure
In humans, SKIDA1 is located on the reverse strand of chromosome 10 at locus 10p12.31. It contains five exons.
Isoforms
There is not a consensus on whether humans have one or two SKIDA1 isoforms. NCBI Gene claims there is one, while UniProt claims there are two. It's possible isoform 2 is recorded in NCBI Gene as DLN-1 (accession BAE93016.1). Isoform 1 is 908 amino acids long, while isoform 2 is 827 amino acids long; isoform 2 is missing amino acids 240-318 from isoform 1. Isoform 1 is predicted to weigh 98 kDa and have an isoelectric point of 8.7, while isoform 2 is predicted to weigh 90 kDa and have an isoelectric point of 7.6.
Other mammalian species also have multiple isoforms of SKIDA1, including carnivorans, rodents, and primates. The number of isoforms each species has varies: cheetahs have five recorded isoforms, chimpanzees have three recorded, and brown rats have two recorded.
Amino Acid Repeats
Human SKIDA1 contains two poly-alanine regions, one poly-histidine region, and one poly-glutamic acid region. It's unknown if they have any function. The poly-alanine and poly-histidine regions are not highly conserved among orthologs; for example, while they are found in the house mouse ortholog, they are not found in the western lowland gorilla ortholog. The poly-glutamic acid region shows more conservation, and is found abbreviated in species as distantly related from humans as the tire track eel.
Domains
SKIDA1 contains two domains: Ski/Sno/Dac and DUF4854. The Ski/Sno/Dac domain is at the N-terminus end of the protein. The Ski/Sno/Dac domain is also found in the proteins Ski, Ski-like protein, and dachshund. It is potentially a DNA-binding domain.
The other domain, DUF4854, is also found in EPOP, near its C-terminus. However, the DUF4584 found in EPOP is roughly a fifth the size of that in SKIDA1. The C-termini of SKIDA1 (amino acids 844-908) and EPOP (amino acids 313-379) have 52% identity. The C-terminus of EPOP binds to the SUZ12 subunit of Polycomb Repressive Complex 2 (PRC2), suggesting that of SKIDA1 may as well.
Regulation
Promoter and Transcription Factors
In humans, there are five predicted potential promoters. Two align with the second half of the mRNA transcript, suggesting they are not used or only produce an incomplete polypeptide.
The promoter that aligns best with the start of the mRNA transcript is potentially bound to by many transcription factors, including Transcription factor II B, Nuclear factor Y, Early growth response 1, and Krueppel-like factor 6. It does not contain a TATA box.
Transcript Regulation
SKIDA1 is regulated by microRNAs. miR-93 binds to the SKIDA1 3'-UTR. Multiple microRNAs are predicted to bind to the SKIDA1 3'-UTR, including miR-130, miR-301, miR-454, and miR-494.
Polypeptide Modification
SKIDA1 is SUMOylated at five sites. Additional sites are predicted to be SUMOylated. SKIDA1 is also predicted to be phosphorylated and O-GlcNAcylated.
Expression
Subcellular Localization
SKIDA1 is predicted to be localized primarily in the nucleus and less so in the cytosol.
Tissue Expression
SKIDA1 is expressed at high levels in the brain, thyroid, and testes. It's expressed at medium to low levels in adipose tissue, lymph nodes, and skeletal muscle. In mice, it's noted to have medium-to-high expression in the olfactory bulb, retina, and salivary gland.
Developmental Expression
SKIDA1 expression changes during organism development. Expression is low in the zygote, peaks during embryonic development, and is low post-birth. In the house mouse, it's expressed most during organogenesis. In the fetus, its expression is low in the liver but not other organs. Expression in the adult liver is much higher. In contrast, SKIDA1 expression in the fetal brain is higher than in the adult brain.
SKIDA1 in the African clawed frog is expressed faintly in the marginal zone of gastrulae. During neurulation, it's expressed in the brain and cranial neural crest. During tailbud, SKIDA1 expression increases in sensory placodes. By the end of tailbud, neural expression has faded except in the olfactory organ.
Function
SKIDA1 is predicted to function primarily in the nucleus and also in the cytosol.
SKIDA1 knockouts in mice have significant differences from wild-type mice in the skeletal, neurological, reproductive, and immune systems. Other significant differences include effected hearing, an enlarged thymus, and increased pre-weaning mortality. Some, but not all, of these effects were found in heterozygous knockouts.
Clinical significance
SKIDA1 expression is associated with multiple types of cancer. It is over-expressed in epithelial ovarian cancer cells. Its expression is altered by various cancer-treatment compounds: human alpha-lactalbumin made lethal to tumor cells; oleate salts; metformin; and aspirin. In cell lines of cancerous cells, altered expression is associated with resistance to dasatinib and docetaxel, which are used to treat cancer.
Altered methylation of SKIDA1 is associated with human pancreatic cancer, rheumatoid arthritis, and lupus erythematosus. Additionally, SKIDA1 is expressed less in women with Down syndrome compared to their identical twins without Down syndrome. Its expression is dramatically reduced in brains affected by untreated HIV1-associated neurocognitive disorders (HAND) in comparison to healthy brains and brains affected by HAND but treated with antiretrovirals.
References
Human proteins
Genes on human chromosome 10
Proteins
Genes
Human genes | SKIDA1 | [
"Chemistry"
] | 1,620 | [
"Biomolecules by chemical classification",
"Proteins",
"Molecular biology"
] |
60,672,870 | https://en.wikipedia.org/wiki/Surface%20growth | In mathematics and physics, surface growth refers to models used in the dynamical study of the growth of a surface, usually by means of a stochastic differential equation of a field.
Examples
Popular growth models include:
KPZ equation
Dimer model
Eden growth model
SOS model
Self-avoiding walk
Abelian sandpile model
Kuramoto–Sivashinsky equation (or the flame equation, for studying the surface of a flame front)
They are studied for their fractal properties, scaling behavior, critical exponents, universality classes, and relations to chaos theory, dynamical system, non-equilibrium / disordered / complex systems.
Popular tools include statistical mechanics, renormalization group, rough path theory, etc.
Kinetic Monte Carlo surface growth model
Kinetic Monte Carlo (KMC) is a form of computer simulation in which atoms and molecules are allowed to interact at given rate that could be controlled based on known physics. This simulation method is typically used in the micro-electrical industry to study crystal surface growth, and it can provide accurate models surface morphology in different growth conditions on a time scales typically ranging from micro-seconds to hours. Experimental methods such as scanning electron microscopy (SEM), X-ray diffraction, and transmission electron microscopy (TEM), and other computer simulation methods such as molecular dynamics (MD), and Monte Carlo simulation (MC) are widely used.
How KMC surface growth works
1. Absorption process
First, the model tries to predict where an atom would land on a surface and its rate at particular environmental conditions, such as temperature and vapor pressure. In order to land on a surface, atoms have to overcome the so-called activation energy barrier. The frequency of passing through the activation barrier can by calculated by the Arrhenius equation:
where A is the thermal frequency of molecular vibration, is the activation energy, k is the Boltzmann constant and T is the absolute temperature.
2. Desorption process
When atoms land on a surface, there are two possibilities. First, they would diffuse on the surface and find other atoms to make a cluster, which will be discussed below. Second, they could come off of the surface or so-called desorption process. The desorption is described exactly as in the absorption process, with the exception of a different activation energy barrier.
For example, if all positions on the surface of the crystal are energy equivalent, the rate of growth can be calculated from Turnbull formula:
where is the rate of growth, ∆G = Ein – Eout, Aout, A0 out are frequencies to go in or out of crystal for any given molecule on the surface, h is the height of the molecule in the growth direction and C0 the concentration of the molecules in direct distance from the surface.
3. Diffusion process on surface
Diffusion process can also be calculated with Arrhenius equation:
where D is the diffusion coefficient and Ed is diffusion activation energy.
All three processes strongly depend on surface morphology at a certain time. For example, atoms tend to lend at the edges of a group of connected atoms, the so-called island, rather than on a flat surface, this reduces the total energy. When atoms diffuse and connect to an island, each atom tends to diffuse no further, because activation energy to detach itself out of the island is much higher. Moreover, if an atom landed on top of an island, it would not diffuse fast enough, and the atom would tend to move down the steps and enlarge it.
Simulation methods
Because of limited computing power, specialized simulation models have been developed for various purposes depending on the time scale:
a) Electronic scale simulations (density function theory, ab-initio molecular dynamics): sub-atomic length scale in femto-second time scale
b) Atomic scale simulations (MD): nano to micro-meter length scale in nano-second time scale
c) Film scale simulation (KMC): micro-meter length scale in micro to hour time scale.
d) Reactor scale simulation (phase field model): meter length scale in year time scale.
Multiscale modeling techniques have also been developed to deal with overlapping time scales.
How to use growth conditions in KMC
The interest of growing a smooth and defect-free surface requires a combination set of physical conditions throughout the process. Such conditions are bond strength, temperature, surface-diffusion limited and supersaturation (or impingement) rate. Using KMC surface growth method, following pictures describe final surface structure at different conditions.
1. Bond strength and temperature
Bond strength and temperature certainly play important roles in the crystal grow process. For high bond strength, when atoms land on a surface, they tend to be closed to atomic surface clusters, which reduce total energy. This behavior results in many isolated cluster formations with a variety of size yielding a rough surface. Temperature, on the other hand, controls the high of the energy barrier.
Conclusion: high bond strength and low temperature is preferred to grow a smoothed surface.
2. Surface and bulk diffusion effect
Thermodynamically, a smooth surface is the lowest ever configuration, which has the smallest surface area. However, it requires a kinetic process such as surface and bulk diffusion to create a perfectly flat surface.
Conclusion: enhancing surface and bulk diffusion will help create a smoother surface.
3. Supersaturation level
Conclusion: low impingement rate helps creating smoother surface.
4. Morphology at different combination of conditions
With the control of all growth conditions such as temperature, bond strength, diffusion, and saturation level, desired morphology could be formed by choosing the right parameters. Following is the demonstration how to obtain some interesting surface features:
See also
Domino tiling
Diffusion-limited growth
Non-Euclidean surface growth
Stochastic partial differential equation
References
Kinetic Monte Carlo
Surface science
Semiconductor device fabrication
Thin film deposition
Coatings | Surface growth | [
"Physics",
"Chemistry",
"Materials_science",
"Mathematics"
] | 1,185 | [
"Thin film deposition",
"Microtechnology",
"Coatings",
"Thin films",
"Surface science",
"Semiconductor device fabrication",
"Condensed matter physics",
"Planes (geometry)",
"Solid state engineering"
] |
60,672,947 | https://en.wikipedia.org/wiki/Heterobimetallic%20catalysis | Heterobimetallic catalysis is an approach to catalysis that employs two different metals to promote a chemical reaction. Included in this definition are cases (Scheme 1) where: 1) each metal activates a different substrate (synergistic catalysis, used interchangeably with the terms "cooperative" and "dual" catalysis.), 2) both metals interact with the same substrate, and 3) only one metal directly interacts with the substrate(s), while the second metal interacts with the first.
In synergistic catalysis
Complexes of palladium catalyze cross-coupling of electrophiles with organometallic nucleophiles, including those derived from lithium, tin, zinc, and boron. One example is Sonogashira coupling, where catalytic amount of copper salt (e.g. CuI) reacts with a terminal alkyne (the pronucleophile) under basic conditions to generate a copper acetylide, which transmetalates onto an arylpalladiumII halide, regenerating the copper halide. Reductive elimination from the arylpalladium acetylide yields the cross-coupled product.
Other organic pronucleophiles are cross-coupled with arylpalladium halides in the following examples (Scheme 2):
1. Gold-catalyzed cyclization of allenoates followed by cross-coupling with aryl iodides yields 4-arylbutenolides
2. Borylcupration of styrenes followed by palladium-catalyzed cross-coupling with aryl halides generates α-aryl-β-boromethyl functionalized arenes. This reaction has been rendered diastereoselective in the case of cyclic styrenes, and an enantioselective variant has also been developed. Enantioselective hydroarylation of styrenes is accomplished similarly via a chiral copper hydride
3. Asymmetric conjugate reduction-allylation of α,β-unsaturated ketones is achieved by Cu-H mediated reduction and subsequent allylation via a chiral PHOX-ligated palladium catalyst
Also of note is the enantioselective allylation of activated nitriles (Scheme 3). A chiral bisphosphine-ligated rhodium catalyst activates the alpha-keto-nitrile component as its corresponding enolate, which is intercepted by a π-allylpalladium complex to yield the α-allylated nitrile in high enantiomeric excess. In the absence of the rhodium catalyst no enantioselectivity is observed, whereas the reaction does not proceed in the absence of palladium.
With preformed heterobimetallic catalysts
Catalyst systems in which both metal centers are contained in the same complex are also known (e.g. Shibasaki catalysts); further examples are provided below.
Ion-paired combinations of early and late transition metal complexes can simultaneously interact with a substrate as both Lewis acid and Lewis base. For example, carbonylative ring expansion of epoxides (Scheme 4) is accomplished by Lewis acid activation by cationic complexes of CrIII, TiIII or AlIII with simultaneous ring opening by the [Co(CO)4]− counterion. Carbonylation of the resultant alkylcobalt followed by lactonization releases the product.
A heterobimetallic bond-breaking process is also employed in the IPrCuFp-catalyzed C-H borylation system developed by Mankad (Scheme 5). Bimetallic cleavage of the B-H bond in pinacolborane generates a copper hydride (IPrCu-H) and an iron boryl [(pin)B-Fp], the latter of which borylates unactivated arenes upon UV irradiation. Bimetallic reductive elimination of H2 from the combination of H-Fp and IPrCu-H restarts the catalytic cycle. The incorporation of copper into the catalyst is essential; C-H borylation using (pin)B-Fp alone is stoichiometric in iron due to dimerization of the HFp byproduct.
Heterobimetallic catalysts containing persistent M1-M2 bonds exhibit altered reactivity due to interaction of the two different metal centers. For example, allylic amination catalyzed by the binuclear complex [Cl2Ti(NtBuPPh2)2-/Pd(η3-CH2C(CH3)CH2)]+ is exceptionally rapid. DFT studies suggest that a Pd→Ti dative interaction accelerates the typically slow reductive elimination step by withdrawing electron density from Pd in the transition state (Scheme 6).
Silica-supported heterobimetallic tantalum iridium catalysts were shown exhibit drastically increased catalytic performances in H/D catalytic exchange reactions with respect to (i) monometallic analogues as well as (ii) homogeneous systems. The key transition state in the C-H activation pathway, computed by DFT, involves (i) donation from the C-H σ orbital to an empty d orbital on the electrophilic early metal (Ta) together with (ii) backdonation from a filled d orbital arising from the late metal (Ir) to the C-H σ* orbital for nucleophilic assistance (Scheme 7). The calculations have shown that steric effects imparted by the ancillary ligands could result in enormous differences in C-H activation energy barriers (ca. 20 kcal/mol-1) in this heterobimetallic cooperative mechanism, indicating that metals accessibility has a drastic impact on the catalytic performances.
In photoredox catalysis
The combination of photoredox catalysis with traditional transition metal catalysis enables the use of visible light to drive challenging steps in a catalytic cycle. For example, nickel-catalyzed aryl amination suffers from a difficult C-N reductive elimination step. Hence instead of nickel, expensive palladium-based precatalysts are often used in combination with sterically encumbered phosphine ligands to facilitate reductive elimination. A more recent approach employs an iridium-based photoredox catalyst to effect single-electron oxidation of the intermediate NiII-amido complex. The resulting NiIII-amido rapidly undergoes reductive elimination, allowing the Ni-catalyzed aryl amination to proceed at room temperature without the use of phosphine ligands.
Biological significance
Enzymes containing two or more different metal centers are found in several important biological systems; for example, the Mo-Fe protein of nitrogenase catalyzes the conversion of N2 to NH3 in nitrogen fixation. Of more relevance to human biology, Cu-Zn superoxide dismutase protects cells from oxidative stress by converting superoxide, O2−, to O2 and hydrogen peroxide
References
Catalysis | Heterobimetallic catalysis | [
"Chemistry"
] | 1,489 | [
"Catalysis",
"Chemical kinetics"
] |
60,674,000 | https://en.wikipedia.org/wiki/ASME%20Y14.5 | ASME Y14.5 is a standard published by the American Society of Mechanical Engineers (ASME) to establish rules, symbols, definitions, requirements, defaults, and recommended practices for stating and interpreting Geometric Dimensions and Tolerances (GD&T). ASME/ANSI issued the first version of this Y-series standard in 1973.
Overview
ASME Y14.5 is a complete definition of Geometric Dimensioning and Tolerancing. It contains 15 sections which cover symbols and datums as well as tolerances of form, orientation, position, profile and runout. It is complemented by ASME Y14.5.1 - Mathematical Definition of Dimensioning and Tolerancing Principles. Together these standards allow for clear and concise detailing of dimensional requirements on a product drawing or electronic drawing package as well as the verification of the requirements on manufactured parts. Effective application of GD&T allows for parts to be verified by dimensional measurements, gauging, or by CMM.
History
The modern standard can trace its roots to the military standard MIL-STD-8 published in 1949. It was revised by MIL-STD-8A in 1953, which introduced the concept of modern GD&T "Rule 1". Further revisions have continued to add new concepts and address new technology like Computer Aided Design and Model-based definition. A list of revisions follows:
ASME Y14.5-2018, "Dimensioning and Tolerancing"
Current Standard
Preceded by ASME Y14.5-2009
ASME Y14.5-2-2017, "Certification of Geometric Dimensioning and Tolerancing Professionals"
Current Standard
Preceded by ASME Y14.5-2-2000
ASME Y14.5-2009
Succeeded by ASME Y14.5-2018
Preceded by ASME Y14.5M-1994
ASME Y14.5M-1994
Succeeded by ASME Y14.5-2009
Reaffirmed in 2004
Preceded by ANSI Y14.5M-1982
ANSI Y14.5M-1982
Preceded by ANSI Y14.5-1973
Reaffirmed in 1988
ANSI Y14.5-1973
Succeeded by ASME Y14.5M-1982
Preceded by USASI Y14.5-1966
USASI Y14.5-1966
Succeeded by ANSI Y14.5-1973
Preceded by ASA Y14.5-1957
ASA Y14.5-1957
Succeeded by USASI Y14.5-1966
Preceded by ASA Z14.1 Series
See also
Geometric dimensioning and tolerancing
CAD standards
References
External links
2018 | Y14.5 - Dimensioning and Tolerancing Official ASME page
American Society of Mechanical Engineers
Technical drawing
ASME standards | ASME Y14.5 | [
"Engineering"
] | 565 | [
"Design engineering",
"Mechanical engineering organizations",
"Civil engineering",
"American Society of Mechanical Engineers",
"Technical drawing"
] |
60,674,062 | https://en.wikipedia.org/wiki/Xanthagaricus%20necopinatus | Xanthagaricus necopinatus is a species of the fungal family Agaricaceae. This species is the first generic report for Bangladesh. It was found in Chondrima Uddan, Dhaka district of Bangladesh.
References
Fungi of Bangladesh
Agaricaceae
Fungus species | Xanthagaricus necopinatus | [
"Biology"
] | 59 | [
"Fungi",
"Fungus species"
] |
60,674,444 | https://en.wikipedia.org/wiki/C22orf23 | C22orf23 (Chromosome 22 Open Reading Frame 23) is a protein which in humans is encoded by the C22orf23 gene. Its predicted secondary structure consists of alpha helices and disordered/coil regions. It is expressed in many tissues and highest in the testes and it is conserved across many orthologs.
Gene
Size and locus
C22orf23 is a gene found in homo sapiens. It is located on Chromosome 22 on the minus strand, map position 22q13.1. It spans 10,620 base pairs. Its mRNA transcript is 1988 base pars long and has 7 exons. Its predicted function is protein binding, and molecular function.
Common aliases
C22orf23's aliases are: UPF0193 Protein EVG1, DJ1039K5.6, EVG1 FLJ32787, and LOC84645.
Protein
Primary sequence
The protein encoded by the mRNA sequence is 217 amino acids in length and has a predicted molecular mass of 25 kDa. The predicted isoelectric point is 9.8. It is located in the nucleus.
Domains and motifs
It is predicted to be an intracellular protein and does not have any predicted transmembrane domains. Due to its location and lack of predicted transmembrane domains, the protein structure is likely a globular protein.
Post-Translational Modifications
C22orf23 has many predicted post-translational modifications such as: phosphorylation sites, cell attachment sequences, N-myristoylation sites, O-linked glycosylation sites, glycation sites, Ac-ASQK cleaved-acetylated sites, and Sumoylation sites. Many of the predicted phosphorylation sites were also predicted to be O-linked glycosylation sites thus the phosphorylation site could be blocked altering that domain's structure or function.
Secondary Structure
The predicted secondary structure consists of alpha helices and disordered/coil regions. The predicted secondary structure model has a 28% coverage of the amino acid sequence with a 42.9% confidence.
Homology
Paralogs
There are currently no known paralogs to C22orf23.
Orthologs
Orthologs can be found in most major groups of species ranging from most similar in primates to most distant in a member of phylum Chytridiomycota. This includes: mammals, reptiles, birds, amphibian, bony fish, cartilaginous fish, invertebrates, and fungi. Orthologs may have first appeared in plants or fungi however it is uncertain.
This table lists several orthologs for C22orf23 and includes their species name, common name, taxonomic order, accession number, sequence length, sequence similarity, and evolutionary date of divergence.
Expression
Promoter
The core promoter is GXP_7541220 (-), and its coordinates are 37953445-37954669 and it is 1225 base pairs long.
Tissue expression
Human expression
Protein expression is highest in the testes however it is also expressed at low levels in many other tissues such as: brain, kidney, stomach, skin, thyroid, urinary bladder, placenta, endometrium, esophagus, and appendix, bone marrow, adipose, lung, and ovary.
Ortholog expression
Expression in orthologs Rattus norvegicus, is expressed primarily in the testes with low levels of expression in the: kidneys, lungs, heart, and uterus. Mus musculus is expressed primarily in the adrenal and testes, and also notably expressed in the: bladder, abdomen, heart, lungs, ovaries, and mammary gland.
Interactions
Protein Interactions
There are several predicted protein interactions: Cyclin-D1-binding protein 1 which may regulate cell cycle progression, Vacuolar protein sorting-associated protein 28 homolog which is involved as a regulator of vesicular trafficking, UPF0739 protein C1orf74, and estrogen related receptor gamma. These interacting proteins were identified as either having direct interactions or physical associations. They were identified through a variety of detection methods including affinity chromatography, 2 hybrid prey pooling, and 2 hybrid array. It also has predicted protein interactions with SH3 domain containing 19, EvC ciliary complex subunit 1, RIMS binding protein 3B, RIMS binding protein 3C,TSSK6-activating co-chaperone protein, V-set and immunoglobulin domain containing 8, family with sequence similarity 124 member B, small nucleolar RNA host gene 28, and transmembrane protein 200B. Evidence suggesting a functional link for these interactions were supported through Co-mention on PubMed.
Clinical Significance
Disease Association
C22orf23 was identified as belonging to one of two groups of pooled serum samples in a study that analyzed the difference between serum glycoproteins of hepatocellular carcinoma and that of normal serum. Deletions of parts of C22orf23 (exons 3 and 4) and several other genes including SOX10 has been observed in patients with peripheral demyelinating neuropathy, central demyelinating leukodystrophy, Waardenburg Syndrome, and Hirschsprung disease and is therefore, suggested to be a potential factor involved in these ailments. C22orf23 was also mentioned in a study of mutation profiles from ER+ breast cancer samples taken from postmenopausal patience. There were mutations found that affected C22orf23 among many other genes. In a study of epigenetic alterations involved in coronary artery disease, C22orf23 was found to have altered epigenetic modifications which could be involved in novel genes in Coronary artery disease. In a study that attempts to predict imprinted genes that maybe linked to Human disorders, C22orf23 was identified as homologous of imprinted Gene candidates showing linkage to schizophrenia. In another study it was listed as being a potently regulated protein in uterine leiomyoma.
Mutations
There are a total of 3340 SNPs within the 5’ and 3’ UTR, introns, exons, as well as some genes near the 5’ and 3’ UTR. There is a total of 225 SNPs within the coding sequence. Some of the SNPs occur in conserved amino acids within the coding sequence and some reported have one or more types of validation. Some of the SNPs have high heterozygosity scores and thus have a presence in the population.
References
Proteins
Genes on human chromosome 22 | C22orf23 | [
"Chemistry"
] | 1,384 | [
"Biomolecules by chemical classification",
"Proteins",
"Molecular biology"
] |
60,674,571 | https://en.wikipedia.org/wiki/Anne-Claude%20Gingras | Anne-Claude Gingras is a senior investigator at Lunenfeld-Tanenbaum Research Institute, and a professor in the department of molecular genetics at the University of Toronto. She is an expert in mass spectrometry based proteomics technology that allows identification and quantification of protein from various biological samples.
Biography
Gingras was born on Île d'Orléans, Quebec. She earned her undergraduate degree at Université Laval in Quebec. She completed her PhD in biochemistry at McGill University in Montreal, studying how 4E-BP1 regulated translation initiation, under the mentorship of Nahum Sonenberg. After graduating in 2001, she began postdoctoral research in Seattle at the Institute for Systems Biology in the lab of Ruedi Aebersold, where she studied proteomics for three years.
In 2005, Gingras moved to Toronto and joined the Lunenfeld-Tanenbaum Research Institute, and in 2006, she began teaching at the University of Toronto in the department of molecular genetics.
Career
Gingras research focuses on the development of experimental and bioinformatics approaches for functional proteomics, with a focus on protein-protein and proximity interactions. She applies these tools to the study of signaling pathways in health and disease and in mapping the physical organization of the dynamic proteome. Some of her work focuses on the consequence of disease-associated mutations on the interactions established by proteins.
In addition to proteomics, Gingras laboratory has interest in studying human protein phosphatase and their systematic interactions and has now expanded into the field of systems biology.
Achievements and awards
Gingras has published > 200 articles that have been cited > 35,000 times (Google Scholar; Feb 2020). In 2011, Gingras was named one of Canada's Top 100 Most Powerful Women. In 2015, Gingras was elected a fellow of the Royal Society of Canada. Her work on interaction proteomics, was awarded, alongside John Yates, the Discovery Award in Proteomics from the Human Proteome Organization (2019). She also received the Jeanne Manery Fisher Memorial Lecture award at the 2019 meeting of the Canadian Society for Molecular Biosciences.
Selected publications
Gingras, Anne-Claude; Raught, Brian; Sonenberg, Nahum (1999-06-01). "eIF4 Initiation Factors: Effectors of mRNA Recruitment to Ribosomes and Regulators of Translation". Annual Review of Biochemistry. 68 (1): 913–963.
Sonenberg, Nahum; Lawrence, John C.; Lin, Tai-An; Donzé, Olivier; Gingras, Anne-Claude; Belsham, Graham J.; Pause, Arnim (1994-10). "Insulin-dependent stimulation of protein synthesis by phosphorylation of a regulator of 5'-cap function". Nature. 371 (6500): 762–767.
Sonenberg, Nahum; Raught, Brian; Gingras, Anne-Claude (2001-04-01). "Regulation of translation initiation by FRAP/mTOR". Genes & Development. 15(7): 807–826.
Sonenberg, Nahum; Aebersold, Ruedi; Hoekstra, Merl F.; Abraham, Robert T.; Polakiewicz, Roberto D.; Raught, Brian; Gygi, Steven P.; Gingras, Anne-Claude (1999-06-01). "Regulation of 4E-BP1 phosphorylation: a novel two-step mechanism". Genes & Development. 13 (11): 1422–1437.
Hay, Nissim; Sonenberg, Nahum; O’Leary, Maura A.; Kennedy, Scott G.; Gingras, Anne-Claude (1998-02-15). "4E-BP1, a repressor of mRNA translation, is phosphorylated and inactivated by the Akt(PKB) signaling pathway". Genes & Development. 12 (4): 502–513.
Sonenberg, Nahum; Aebersold, Ruedi; Wyslouch-Cieszynska, Aleksandra; Polakiewicz, Roberto D.; Burley, Stephen K.; Miron, Mathieu; Niedzwiecka, Anna; Gygi, Steven P.; Raught, Brian (2001-11-01). "Hierarchical phosphorylation of the translation inhibitor 4E-BP1". Genes & Development. 15 (21): 2852–2864.
Sonenberg, Nahum; Gingras, Anne-Claude; Raught, Brian (2001-06-19). "The target of rapamycin (TOR) proteins". Proceedings of the National Academy of Sciences. 98 (13): 7037–7044.
References
Fellows of the Royal Society of Canada
Academic staff of the University of Toronto
Canadian biochemists
Living people
Women biochemists
People from Capitale-Nationale
Scientists from Quebec
McGill University Faculty of Science alumni
Université Laval alumni
21st-century Canadian biologists
21st-century Canadian women scientists
Year of birth missing (living people)
Mass spectrometrists | Anne-Claude Gingras | [
"Physics",
"Chemistry"
] | 1,084 | [
"Spectrum (physical sciences)",
"Mass spectrometrists",
"Mass spectrometry",
"Women biochemists",
"Biochemists"
] |
60,674,985 | https://en.wikipedia.org/wiki/Freezing%20point%20depression%20osmometer | The freezing point depression osmometer is an osmometer that is used in determining a solution's osmotic concentration as its osmotically active aspects depress its freezing point.
In the past, freezing point osmometry has been used to assess the osmotic strength of colloids and solutions. The osmometer uses the solution's freezing point depression to establish its strength. It is also used to determine the level of osmotically appropriate body fluid in various chemicals dissolved in the blood using the relationship in which a mole of dissolved substance reduces the freezing point of a kilogram of water by . The freezing point depression osmometer is also used in various medical practices, including pharmaceutical manufacturing, quality control laboratories, and clinical chemistry.
Method
Freezing point depression osmometers are utilized to determine a solution's osmotic strength. It is the approach that is most frequently used for a variety of medical tasks. It is used in assessing the osmotic strength of colloids as well as solutions.
The freezing point depression osmometer operates by using the solution's freezing point to determine the concentration of the solution. It uses a nanoliter nanometer, a device that facilitates the establishment of the solution's melting and freezing points. Calibration, loading, deep freezing, and determination are the four separate procedures involved in determining the freezing and melting points. The concentration of the solution can be determined by knowing the number of particles present in it, which can be done by determining the freezing point of the solution.
When particles are dissolved in a solution, their freezing point is lowered compared to that of the original solvent. A further increase in the solute decreases the freezing point even further. The freezing point depression osmometer uses the solution's freezing point to establish its concentration. The freezing point depression osmometer is calibrated using standards that are within the solution's osmolality range.
History of use
The use of osmometers began in the late nineteenth century after Van't Hoff won a Nobel Prize for his research and discovery that the relationship between the osmotic pressure of dilute colloid solutions and concentration was consistent with the ideal gas law. Since then, osmometers have been used to measure the osmotic strength of a diluted solution at different levels of concentration.
One of the earliest uses of the method was in an analytical study, in which the urine osmolality of 1,991 dogs was tested. The study established its advantages over other conventional concentration osmometers which rely on the osmotic pressure profile and it was found to be ideal for dilute, biological samples.
Current usage in medical fields
Freezing point depression osmometers are applied in various areas of the medical field. The approach is used in determining the colloidal aspects of solutions. In the present day, the method is applied, among other areas, in measuring osmolarity in lens care solutions as well as eye drops. It is further used in clinical chemistry, pharmaceutical, and quality control laboratories, where it facilitates different processes. As compared to the other methods, the freezing point depression osmometer has a high level of precision and accuracy, making its application in clinical practices safe. It is applied in various processes that involve the manufacturing of drugs. Urine osmolality is also used to measure urine concentration accurately and thus determine renal function and body fluid homeostasis.
Evaluation of its use
Osmometry is widely used in pharmaceuticals, quality control laboratories, and clinical chemistry to measure the osmolality in aqueous solutions accurately. It is commonly used in medical clinics to assist with various pharmaceutical practices, including the development of lens care solutions and eye drops.
Alternatives
Alternative osmometer methods include membrane osmometry, which determines the osmotic pressure of solutions, and vapor pressure osmometry, which assesses the concentration of particles that minimize a solution's vapor pressure and melting, as well as the freezing points of aqueous solutions.
See also
Melting-point depression
Boiling-point elevation
Colligative properties
Further reading
Skoog, D.A.; West, D.M.; Holler, F.J. Fundamentals of Analytical Chemistry New York: Saunders College Publishing, 5th Edition, 1988.
Bard, A.J.; Faulkner, L.R. Electrochemical Methods: Fundamentals and Applications. New York: John Wiley & Sons, 2nd Edition, 2000.
Bettencourt da Silva, R; Bulska, E; Godlewska-Zylkiewicz, B; Hedrich, M; Majcen, N; Magnusson, B; Marincic, S; Papadakis, I; Patriarca, M; Vassileva, E; Taylor, P; Analytical measurement: measurement uncertainty and statistics, 2012, .
External links
General Chemistry principles, patterns,and applications.
References
Measuring instruments
Membrane technology | Freezing point depression osmometer | [
"Chemistry",
"Technology",
"Engineering"
] | 1,006 | [
"Membrane technology",
"Measuring instruments",
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60,675,240 | https://en.wikipedia.org/wiki/Xanthagaricus%20caeruleus | Xanthagaricus caeruleus is a species of the fungal family Agaricaceae. This species is described from China.
References
Fungi of China
Agaricaceae
Fungus species | Xanthagaricus caeruleus | [
"Biology"
] | 40 | [
"Fungi",
"Fungus species"
] |
60,675,541 | https://en.wikipedia.org/wiki/Xanthagaricus%20flavosquamosus | Xanthagaricus flavosquamosus is a species of the fungal family Agaricaceae.This species is described from China.
References
Fungi of China
Agaricaceae
Fungus species | Xanthagaricus flavosquamosus | [
"Biology"
] | 42 | [
"Fungi",
"Fungus species"
] |
60,675,716 | https://en.wikipedia.org/wiki/Rossbeevera%20eucyanea | Rossbeevera eucyanea is a species of the fungal family Boletaceae. This species was described from Japan.
References
Fungi of China
Boletaceae
Fungus species | Rossbeevera eucyanea | [
"Biology"
] | 36 | [
"Fungi",
"Fungus species"
] |
60,675,751 | https://en.wikipedia.org/wiki/Rossbeevera%20griseobrunnea | Rossbeevera griseobrunnea is a species of the fungal family Boletaceae. This species was first described in April 2019 from southern China.
References
Fungi of China
Boletaceae
Fungus species | Rossbeevera griseobrunnea | [
"Biology"
] | 42 | [
"Fungi",
"Fungus species"
] |
60,677,420 | https://en.wikipedia.org/wiki/NIMPLY%20gate | The NIMPLY gate is a digital logic gate that implements a material nonimplication.
Symbols
A right-facing arrow with a line through it () can be used to denote NIMPLY in algebraic expressions. Logically, it is equivalent to material nonimplication, and the logical expression A ∧ ¬B.
Usage
The NIMPLY gate is often used in synthetic biology and genetic circuits.
See also
IMPLY gate
AND gate
NOT gate
NAND gate
NOR gate
XOR gate
XNOR gate
Boolean algebra (logic)
Logic gates
References
Logic gates | NIMPLY gate | [
"Technology"
] | 112 | [
"Computing stubs"
] |
60,678,892 | https://en.wikipedia.org/wiki/Transaction%20Protocol%20Data%20Unit | The Transaction Protocol Data Unit (TPDU) is a packet-based protocol originally designed for financial transaction processing over an X.25 network.
References
Data unit | Transaction Protocol Data Unit | [
"Technology"
] | 34 | [
"Computing stubs",
"Computer network stubs"
] |
60,680,967 | https://en.wikipedia.org/wiki/Clive%20Wynne | Clive D. L. Wynne (born 1961) is a British-Australian ethologist specializing in the behavior of dogs and their wild relatives. He has worked in the United States, Australia, and Europe, and is currently based at Arizona State University in Tempe, AZ. He was born and raised on the Isle of Wight, off the south coast of England, studied at University College London, and got his Ph.D. at Edinburgh University. He has studied the behavior of many species - ranging from pigeons to dunnarts, but starting around 2006 melded his childhood love of dogs with his professional training and now studies and teaches about the behavior of dogs and their wild relatives.
Education and career
Wynne was educated at schools on the Isle of Wight including the now defunct Sandown High School, studied for his B.Sc. in Human Sciences at University College London, where he was influenced by the evolutionary psychologist Henry Plotkin. Wynne obtained his Ph.D. in Psychology for a dissertation on the behavior of barbary (turtle) doves at Edinburgh University in 1986. After time as a post-doc at the Ruhr-Universitat Bochum, Duke University, and the Universität Konstanz, where he was mentored by John Staddon and Juan Delius, Wynne's first faculty position was at the University of Western Australia. In 2002 Wynne moved to the University of Florida, and he came to Arizona State University in 2013 where he founded the Canine Science Collaboratory.
Research interests
Wynne's earlier research focused on the cognitive abilities of pigeons (e.g., Wynne et al. 1992; Wynne 1997), as well as their perception of arbitrary short time intervals (e.g., Wynne et al. 1996). In Australia, Wynne studied the learning abilities of two species of marsupial, the fat-tailed dunnart (Sminthopsis crassicaudata) and the quokka (Setonix brachyurus) (e.g., Bonney and Wynne 2002a; 2002b) and he is known for his opposition to anthropomorphism in the understanding of animal cognition (e.g., Wynne 2004).
The specific focus of Wynne's ongoing research is the behaviour of dogs and their wild relatives. In this domain his group studies the ability of pet dogs to react adaptively to the behaviours of the people they live with; the deployment of applied behaviour analytic techniques to the treatment of problem behaviours in dogs; the behaviours of shelter dogs that influence their chances of adoption into human homes; improved methods for training sniffer dogs; the development of test banks for studying cognitive aging in pet dogs; and humans as social enrichment for captive canids.
In 2017 Wynne and his collaborators organized the inaugural Canine Science Conference in Tempe, AZ - the first of its kind in North America.
Books
Animal Cognition: The Mental Lives of Animals (Palgrave)
Do Animals Think? (Princeton University Press)
Animal Cognition: Evolution, Behavior, and Cognition (Palgrave Macmillan))
Dog Is Love: Why and How Your Dog Loves You (Houghton Mifflin Harcourt)
References
1961 births
Living people
Alumni of University College London
Animal cognition writers
People from the Isle of Wight
Alumni of the University of Edinburgh
British emigrants to Australia
University of Florida faculty
Arizona State University faculty
Academic staff of the University of Western Australia
British expatriates in Germany
21st-century Australian male writers
British expatriate academics in the United States
Ethologists
21st-century British scientists
21st-century British male writers
21st-century Australian scientists | Clive Wynne | [
"Biology"
] | 748 | [
"Ethology",
"Behavior",
"Ethologists"
] |
60,681,584 | https://en.wikipedia.org/wiki/Professor%20of%20Physical%20Chemistry%20%28Cambridge%29 | The Professorship of Physical Chemistry is a permanently-established professorship at the University of Cambridge, created in 1920. For the first six decades of its existence, the incumbent was also Head of the Department of Physical Chemistry – a separate entity from the then Department of Chemistry, albeit latterly occupying the same building in Lensfield Road. Following the merger of these two departments in the early 1980s, holders of this Chair have often served as Head of the current unified Department of Chemistry.
Occupants of the chair to date have been:
Martin Lowry (1920–1936),proposed the Brønsted–Lowry acid–base theory
Ronald G. W. Norrish (1937–1965),Nobel laureate in Chemistry (1967), developed the Norrish reaction
Jack Linnett (1965-1975),Master of Sidney Sussex College (1970–1975) Vice-Chancellor (1973–1975), proposed the Linnett double-quartet theory
John Meurig Thomas (1978–1987),Master of Peterhouse (1993–2002), Royal Medallist (2016), a founder of solid-state chemistry
Sir David King (1988–2006),Master of Downing College (1995–2000), Government Chief Scientific Adviser (2000–2008), chair of Independent SAGE (2020–)
John Pyle (2007–2018),Davy Medallist (2018), co-chair of the scientific assessment panel for the Montreal Protocol
Tuomas Knowles (2023–), Corday-Morgan Prize recipient (awarded in 2017)
In addition to the 1920 professorship, the university established a second Professorships of Physical Chemistry for a single tenure (i.e. as personal chair) for Brian Thrush, who held the office from 1978 to 1995.
References
Physical Chemistry
Faculty of Physics and Chemistry, University of Cambridge
1920 establishments in England
Physical Chemistry, *, Cambridge, 1920 | Professor of Physical Chemistry (Cambridge) | [
"Chemistry"
] | 373 | [
"Professors of Physical Chemistry (Cambridge)",
"Physical chemists"
] |
47,336,626 | https://en.wikipedia.org/wiki/Oriented%20energy%20filters | Oriented energy filters are used to grant sight to intelligent machines and sensors. The light comes in and is filtered so that it can be properly computed and analyzed by the computer allowing it to “perceive” what it is measuring. These energy measurements are then calculated to take a real time measurement of the oriented space time structure.
3D Gaussian filters are used to extract orientation measurements. They were chosen due to their ability to capture a broad spectrum and easy and efficient computations.
The use of these vision systems can then be used in smart room, human interface and surveillance applications. The computations used can tell more than the standalone frame that most perceived motion devices such as a television frame. The objects captured by these devices would tell the velocity and energy of an object and its direction in relation to space and time. This also allows for better tracking ability and recognition.
References
Artificial intelligence engineering
Lidar | Oriented energy filters | [
"Engineering"
] | 179 | [
"Artificial intelligence engineering",
"Software engineering"
] |
47,336,979 | https://en.wikipedia.org/wiki/FG-46 | The FG-46 (a.k.a. EPKM and SpaB-170) is a Chinese spin stabilized solid rocket motor burning HTPB-based composite propellant. It was developed by China Hexi Chemical and Machinery Corporation (also known as the 6th Academy of CASIC) for use in the Long March 2E on GTO missions. It first flew as a prototype SPTS-M14 on July 16, 1990 on the Badr A mission. It had its first commercial mission orbiting the AsiaSat 2 on November 28, 1995 and exactly one month later, on December 28 its second and last mission for EchoStar 1.
It has a total nominal mass of , of which is propellant load and its burn out mass is . It has an average thrust of with a specific impulse of 292 seconds burning for 87 seconds, with a total impulse of . It is spin stabilized at 40 rpm and the propellant mass can be reduced by up to eight months before launch or up to on the launch site.
References
Rocket engines of China
Solid-fuel rockets | FG-46 | [
"Astronomy"
] | 217 | [
"Rocketry stubs",
"Astronomy stubs"
] |
47,337,812 | https://en.wikipedia.org/wiki/Romy%20Achituv | Romy Achituv (Hebrew: רומי אחיטוב; born 1958) is an Israeli experimental multimedia artist whose work engages issues of representation, language, time, and memory. Achituv is known for "Text Rain" which he co-created with Camille Utterback and "The Garden Library Database Visualization Project" which he created with Arteam, an interdisciplinary art collective.
Achituv was born in Rome, Italy. He lives and works in Israel, New York City, and Seoul, South Korea. His work is in the collection of the Smithsonian American Art Museum (Washington, D.C.).
References
External links
1958 births
Living people
Artists from Rome
Multimedia artists
Israeli artists | Romy Achituv | [
"Technology"
] | 150 | [
"Multimedia",
"Multimedia artists"
] |
47,337,977 | https://en.wikipedia.org/wiki/Variant%20of%20uncertain%20significance | A variant of uncertain (or unknown) significance (VUS) is a genetic variant that has been identified through genetic testing but whose significance to the function or health of an organism is not known. Two related terms are "gene of uncertain significance" (GUS), which refers to a gene that has been identified through genome sequencing but whose connection to a human disease has not been established, and "insignificant mutation", referring to a gene variant that has no impact on the health or function of an organism. The term "variant' is favored in clinical practice over "mutation" because it can be used to describe an allele more precisely (i.e. without inherently connoting pathogenicity). When the variant has no impact on health, it is called a "benign variant". When it is associated with a disease, it is called a "pathogenic variant". A "pharmacogenomic variant" has an effect only when an individual takes a particular drug and therefore is neither benign nor pathogenic.
A VUS is most commonly encountered by people when they get the results of a lab test looking for a mutation in a particular gene. For example, many people know that mutations in the BRCA1 gene are involved in the development of breast cancer because of the publicity surrounding Angelina Jolie's preventative treatment. Few people are aware of the immense number of other genetic variants in and around BRCA1 and other genes that may predispose to hereditary breast and ovarian cancer. A recent study of the genes ATM, BRCA1, BRCA2, CDH1, CHEK2, PALB2 and TP53 found 15,311 DNA sequence variants in only 102 patients. Many of those 15,311 variants have no significant phenotypic effect. That is, a difference can be seen in the DNA sequence, but the differences have no effect on the growth or health of the person.
Identifying variants that are significant or likely to be significant is a difficult task that may require expert human and in silico analysis, laboratory experiments and even information theory. In spite of those efforts, many people may be worried about their particular VUS, even though it has not been determined to be significant or likely to be significant. Most discovered VUSs will not be investigated in a peer-reviewed research paper, as this effort is usually reserved for likely pathogenic variants.
History
In 2001, an initial draft of the human genome was published by the International Human Genome Sequencing Consortium. With the development of next-generation sequencing, the cost of sequencing has plummeted and the number of human genomes and exomes sequenced each year is increasing dramatically. , the cost of a quality whole genome sequence is $1,000 or less. If the ratio of approximately 20 DNA sequence variants per gene holds over the entire genome (with approximately 20,000 genes) that means that every person who elects to have their genome sequenced will be provided with almost half a million Variants of Unknown Significance. To assist people to understand the meaning of all these variants, classification is a first step.
Classification
In 2015, the American College of Medical Genetics and Genomics (ACMG), the Association for Molecular Pathology (AMP), and the College of American Pathologists (CAP) published a third revision of their guidelines on variant interpretation in Mendelian disorders. The publication recommended the following categories: pathogenic, likely pathogenic, uncertain significance, likely benign, and benign. This guideline is one of many resources published by the ACMG in hopes of improving standardization of variant interpretation and reporting.
, there continues to be limited involvement from federal agencies to regulate the clinical validity (accuracy) and utility (risks and benefits) of genetic testing. Variant interpretation and classification is notably subjective, as laboratories developed their own criteria prior to the ACMG-AMP guidelines. This subjectiveness is further problematic when there is evidence that variant significance changes over time. Due to the lack of consistency in official guidelines, the genomics community is left struggling to efficiently categorize genetic variants.
Pathogenic
This category is reserved for variants that are well-documented to cause disease. Pathogenicity should be reported with respect to a specific condition and inheritance pattern (e.g., autosomal recessive or dominant). A pathogenic variant meets stringent criteria such as evidence from well-established functional studies or being identified in multiple unrelated individuals with the disease.
Likely pathogenic
Variants in this category show strong evidence of being disease-causing but lack definitive proof. The term “likely pathogenic” indicates that the data supports a high likelihood (greater than 90%) that the variant is pathogenic.
Uncertain significance
This category is for variants where there is unknown or conflicting clinical significance. Additional evidence is needed in order to determine whether or not the variant is causative for a particular disease. As additional data and research emerges over time, variants of unknown significance may get moved to other categories, frequently towards the benign or likely benign categories.
Likely benign
This category is used for variants that are unlikely to be causative of disease, typically supported by population frequency data or functional studies suggesting no deleterious impact. A “likely benign” classification implies more than 90% certainty that the variant is not causative for a disease.
Benign
This category is for variants that are not disease-causing. These variants are usually observed at high frequencies in population databases and have strong evidence against a pathogenic effect, including predictive computational models and experimental data showing no effect on the encoded protein.
Limitations of the classifications
Less than 5% of the human genome encodes proteins, and the rest is associated with non-coding RNA molecules, regulatory DNA sequences, LINEs, SINEs, introns, and sequences for which as yet no function has been determined. Thus, only a small fraction of the almost half-million VUS's that are expected to be identified by whole genome sequencing can be categorized into the 5 categories above, leaving the patient nearly as uninformed about their variants as they would have been without this information.
Most of the base sequences regulating gene expression are found outside of protein-coding sequences, either within introns or outside of genes in intergenic regions. Changes in those regulatory regions can lead to dysfunction of a gene(s) and produce phenotypic effects that can be relevant to health and function.
An example of a variant in an intergenic enhancer is one that is associated with blond hair color in northern Europeans. The variant in an enhancer of the KITLG gene causes only a 20% change in gene expression, yet causes hair lightening.
An example of an intronic VUS controlling gene expression is the SNP found in an intron of the FTO gene. The FTO gene encodes the fat mass and obesity-associated protein, and the SNP (or VUS) found in its intron was shown by genome-wide association studies to be associated with an increased risk for obesity and diabetes. The initial assumption was that this mutation was misregulating FTO to cause the disease risk. However, it was later shown that the intronic variant was in fact regulating the distant IRX3 gene and not the FTO gene. That is just one example of how difficult it can be to determine the significance of a VUS even when many research labs are focused on it, and it illustrates that clinicians cannot reliably interpret genetic results that have not been fully clarified by prior research.
Applications
The number of VUS reports makes it impossible to mention all such reports. To give a flavor for some applications in one field, it is perhaps of most interest to focus on breast cancer. Remember, this is only a fraction of the information available world-wide about VUS reports related to breast cancer, and as always, your results may vary.
In a 2009 US study of over 200 women who received BRCA VUS reports and were surveyed for one year thereafter, distress over the result persisted for the year.
A 2012 survey of patient outcomes in the Netherlands found that, after genetic counseling for BRCA VUS, patients perceived themselves to have different cancer risks than what had been explained to them by genetic counselors, and that this misperception influenced decisions about radical medical procedures.
In a 2015 study in the UK, where BRCA VUSs occur in 10-20% of tests, 39% of breast cancer specialists taking part in the study did not know how to explain a VUS report to a patient with no family history, and 71% were unsure about the clinical implications of the test reports.
References
Further reading
External links
Craig Venter discusses the impact of the human genome project: From Designing Life to Prolonging Healthy Life -- J. Craig Venter (UCTV Published on Jan 25, 2017)
When Results Leave the Lab: Practice Challenges Associated With Germline Genetic Testing in Cancer Care (UWTV Published on Jan 30, 2017)
Genes
Human genome projects
Mutated genes
Genetic epidemiology
Genetic diseases and disorders
Cancer screening | Variant of uncertain significance | [
"Biology"
] | 1,829 | [
"Human genome projects",
"Genome projects"
] |
47,338,295 | https://en.wikipedia.org/wiki/Sound%20localization%20in%20owls | Most owls are nocturnal or crepuscular birds of prey. Because they hunt at night, they must rely on non-visual senses. Experiments by Roger Payne have shown that owls are sensitive to the sounds made by their prey, not the heat or the smell. In fact, the sound cues are both necessary and sufficient for localization of mice from a distant location where they are perched. For this to work, the owls must be able to accurately localize both the azimuth and the elevation of the sound source.
Introduction to sound localization
Owls are very adept nocturnal predators, hunting prey that includes small mammals, reptiles, and insects. They are able to rotate their head up to 270 degrees, lock onto prey, and launch a silent attack. Owls lock onto prey by using sound localization. Sound localization is an animal’s ability to identify the origin of a sound in distance and direction. Several owl species have ears that are asymmetrical in size and location, which enhances this ability. These species include barn owls (Tyto alba), northern saw-whet owls (Aegolius acadicus), and long-eared owls (Asio otus). The barn owl (Tyto alba) is the most commonly studied for sound localization because they use similar methods to humans for interpreting interaural time differences in the horizontal plane. This species has evolved a specialized set of pathways in the brain that allow them to hear a sound and map out the possible location of the object that elicited that sound. Sound waves enter the ear via the ear canal and travel until they reach the tympanic membrane. The tympanic membrane then sends these waves through the ossicles of the middle ear and into the inner ear that includes the vestibular organ, cochlea, and auditory nerve. They are then able to use interaural time difference (ITD) and interaural level difference (ILD) to pinpoint the location and elevation of their prey.
Anatomy of the ear
Owls tend to have asymmetric ears, with the openings being placed just behind the eyes. The shape of the ear opening, known as the aperture, depends on the species. In some species, the opening has a valve, called an operculum, covering it. The left ear opening is typically positioned a bit higher than the right ear opening to aid with sound localization and the detection of prey, even in the dark. During flight, the left ear receives sounds from below them and the right ear receives sounds from above them. The feathers on the edge of barn owl’s face creates a disc that works to trap and focus sound, similar to the outer ears of humans. The sound waves travel through the owl’s ear canal until they reach the eardrum, through the ossicles, and into the inner ear so that the owl is able to perceive exactly where their prey is located. As owls depend on their ability to track prey using their super sense of hearing in order to survive, it is important to understand the structures of the ear of barn owls that work to transmit these sounds.
The inner ear of barn owls includes the vestibular organ, cochlea, and auditory nerve. The anatomy of the inner ear in barn owls was studied in an experiment where three owls were utilized and fixed at laboratories by the intravascular perfusion of 1% formaldehyde and 1.25% glutaraldehyde in a 0.1 phosphate buffer. The temporal lobes of the owls were then removed from the skulls, post-fixed in 1% osmium tetroxide, dehydrated, then embedded in Araldite to study the anatomy of the inner ear. This study revealed that the basilar papilla of barn owls has two unique features being a proliferation of lenticular cells and a thickening of the basilar membrane.
The cochlear duct of the owl contains the basilar papilla, the tectorial membrane, the tegmentum vasculum, and the macula of the lagena. The basilar papilla of the cochlea was measured to be 9.5-11.5 mm long. Proximal sensory hair cells contained mostly short hair cells along with a few intermediate hair cells, but absolutely no tall hair cells. Tall hair cells are only present on the distal half of the owl’s papilla, starting at about 5 mm from the proximal end, along with some short-haired cells. The distal tip of the papilla is occupied exclusively by tall hair cells, whereas the proximal tip is occupied exclusively by lenticular cells.
Two major parts that construct the basilar membrane of the barn owl include the vestibular part and the tympanic part. The vestibular surface of the basilar membrane is covered by supporting cells and a few border cells at the inferior edge of the membrane. The basilar membrane is relatively thin toward the distal end of the papilla, but has a thick fibrous mass toward the proximal end. This dense fibrous mass measured to be about 37-57 μm in width and 8.5-11 μm in thickness among the owls utilized for this study. This mass is not to be confused with the loose fibrous mass of the tympanic part of the basilar membrane that underlies the part of the basilar membrane that is covered by sensory cells. The loose fibrous mass of the tympanic part arises at the proximal tip along with the dense fibrous mass, but the loose fibrous mass covers a greater width of the basilar membrane. The only thing that separates the vestibular and tympanic parts are thin, discontinuous cords of fibers. These cords of fibers are visible at the pendulous tympanic edge of the loose fibrous mass in the proximal part of the papilla, but are much more scattered throughout the mass distally.
How ears asymmetry develops
Researchers have studied the embryonic development of ear asymmetry in the American barn owl (Tyto furcata pratincola) in the frame of 42 different stages of embryonic development. The experiment began by taking 19 embryos from the Institute of Biology to RWTH Aachen University. The embryos were either raised by the hen or were incubated in a Compact S84. The embryos utilized in the study were between stage 29 and stage 41 of embryonic development, with those between stages 36-39 being examined a bit more frequently than others. Micro CT-scans were used to measure the asymmetry of the ear during development, with some scans being taken using the Skyscan 1172. Aluminum filters were used to optimize image quality and phosphotungstic acid (PTA) was used to enhance soft tissue extract in the embryos. Markers were set on the embryonic heads to track differential growth. NRecon was used to reconstruct raw data, three-dimensional objects were calculated in Reconstruct, photographs were produced in Blender, and all final figures were constructed with Matlab and CorelDraw X6. The center of the ear opening, squamosum, stapes, eye lens, nose, and premaxilla were all tracked in the study. The cervical vertebra (C1) and the pituitary gland were used to define the anatomical coordinate system. Measurements of the ear-opening, surface area of the ear, and eccentricity were derived using various equations.
Through the examination of data, the development of ear asymmetry was apparent throughout the stages of embryonic development. The ears appeared slit-like at stage 29 of embryonic development and took on the ellipsoid shape at stage 32, which is also when outer ear development began. Dorso-occipital movement of the outer ear began symmetrically at stage 34, but asymmetry rapidly increased from this dorso-occipital movement by stage 37. Surface area between stages 32 and 35 was 0.4-0.5 mm2, with eccentricity between the right and left ear differing by less than 0.1 mm. Between stages 36 and 37, the surface area was 0.6-1.9 mm2. Eccentricity was no longer measured after stage 37 since the ear-opening shapes were no longer ellipsoid. The rostral margin of the ear opening started to flatten at stage 38, with the higher ear on the head having more dorso-ventral flattening. The angle of flattening margins at stage 38 differed by 18.5 degrees, but by only 16 degrees at stage 39. Ear asymmetry did not increase between stages 40 and 41, as ear asymmetry reached maximum at stage 39. The margin differed by 21 degrees at stage 40 and by 33 degrees at stage 41.
Ear asymmetry appeared to be restricted to the outer ear opening and the outer ear canal, as the auditory system was found to be symmetrically arranged from the eardrum. From the findings of this study, researchers concluded that the ear openings start to move dorso-occipitally at stage 34. The left ear opening begins to move faster than the right ear opening, thus leading to development of ear asymmetry from stage 36 to 39, with maximum asymmetry occurring at stage 39. Researchers suggest that asymmetry produced by further movement in the left ear opening may be caused by the movement of structures within the embryo since this movement does not affect other anatomical landmarks on the left side of the head, as the skull and other anatomical markers in the American barn owl remain to be symmetrical.
ITD and ILD
Owls must be able to determine the necessary angle of descent, i.e. the elevation, in addition to azimuth (horizontal angle to the sound). This bi-coordinate sound localization is accomplished through two binaural cues: the interaural time difference (ITD) and the interaural level difference (ILD), also known as the interaural intensity difference (IID). The ability in owls is unusual; in ground-bound mammals such as mice, ITD and ILD are not utilized in the same manner. In these mammals, ITDs tend to be utilized for localization of lower frequency sounds, while ILDs tend to be used for higher frequency sounds.
ITD occurs whenever the distance from the source of sound to the two ears is different, resulting in differences in the arrival times of the sound at the two ears. When the sound source is directly in front of the owl, there is no ITD, i.e. the ITD is zero. In sound localization, ITDs are used as cues for location in the azimuth. ITD changes systematically with azimuth. Sounds to the right arrive first at the right ear; sounds to the left arrive first at the left ear.
In mammals there is a level difference in sounds at the two ears caused by the sound-shadowing effect of the head. But in many species of owls, level differences arise primarily for sounds that are shifted above or below the elevation of the horizontal plane. This is due to the asymmetry in placement of the ear openings in the owl's head, such that sounds from below the owl are louder in the left and sounds from above are louder in the right. IID is a measure of the difference in the level of the sound as it reaches each ear. In many owls, IIDs for high-frequency sounds (higher than 4 or 5 kHz) are the principal cues for locating sound elevation.
The role of vision in learning sound localization
Owls have a very evolved capacity for sound localization, which has a lot of innate neuronal connections. This provides owls with an advantage over many other mammals, as their neuronal connections do not require much learning. For this reason, visual cues are slightly less important to owls, especially when it comes to utilizing sound localization. Their eyes are nonspherical and immobile in their head, making it difficult for them to orient their eyes towards visual cues.
Dr. Eric Knudsen performed many different experiments on barn owls over the course of several years to study how vision plays a role in their ability to localize sounds. His studies focused on how visual cues help in mapping parts of the forebrain and midbrain, and also tested if vision impairment has an effect on sound localization in juvenile owls. The results from these studies showed that impairing the visual field of juvenile owls did have a slight effect on their responses to visual cues. However, the longer the owls had visual impairment, the easier it was for them to learn to adapt and correct the error of the auditory cues. It has been hypothesized that because owls are born with these innate neuronal connections, they already understand how to use sound localization without having to develop this technique. As for the effect on the brain, Knudsen was able to conclude that if the owl’s optic tectum was inactivated, then the owl’s brain would have changes in the auditory orienting behavior. As the optic tectum is involved in orienting attention, this explains why some of the owls utilized in his study would elicit a response while others would not. It was also found that this inactivation in the optic tectum could lead to a deficiency in sensory or motor space processing.
The results from Knudsen’s studies showed that barn owls have the ability to adapt to vision impairments because of innate neuronal connections that they are born with. Therefore it can be concluded that, unlike most mammals, owls do not often utilize visual cues or stimuli to aid with sound localization. Furthermore, research conducted by Dr. Wagner showed that owls primarily utilize auditory cues for sound localization rather than visual cues.
Parallel processing pathways in the brain
The axons of the auditory nerve originate from the hair cells of the cochlea in the inner ear. Different sound frequencies are encoded by different fibers of the auditory nerve, arranged along the length of the auditory nerve, but codes for the timing and level of the sound are not segregated within the auditory nerve. Instead, the ITD is encoded by phase locking, i.e. firing at or near a particular phase angle of the sinusoidal stimulus sound wave, and the IID is encoded by spike rate. Both parameters are carried by each fiber of the auditory nerve.
The fibers of the auditory nerve innervate both cochlear nuclei in the brainstem, the cochlear nucleus magnocellularis (mammalian anteroventral cochlear nucleus) and the cochlear nucleus angularis (see figure; mammalian posteroventral and dorsal cochlear nuclei). The neurons of the nucleus magnocellularis phase-lock, but are fairly insensitive to variations in sound pressure, while the neurons of the nucleus angularis phase-lock poorly, if at all, but are sensitive to variations in sound pressure. These two nuclei are the starting points of two separate but parallel pathways to the inferior colliculus: the pathway from nucleus magnocellularis processes ITDs, and the pathway from nucleus angularis processes IID.
In the time pathway, the nucleus laminaris (mammalian medial superior olive) is the first site of binaural convergence. It is here that ITD is detected and encoded using neuronal delay lines and coincidence detection, as in the Jeffress model; when phase-locked impulses coming from the left and right ears coincide at a laminaris neuron, the cell fires most strongly. Thus, the nucleus laminaris acts as a delay-line coincidence detector, converting distance traveled to time delay and generating a map of interaural time difference. Neurons from the nucleus laminaris project to the core of the central nucleus of the inferior colliculus and to the anterior lateral lemniscal nucleus.
In the sound level pathway, the posterior lateral lemniscal nucleus (mammalian lateral superior olive) is the site of binaural convergence and where IID is processed. Stimulation of the contralateral ear inhibits and that of the ipsilateral ear excites the neurons of the nuclei in each brain hemisphere independently. The degree of excitation and inhibition depends on sound pressure, and the difference between the strength of the inhibitory input and that of the excitatory input determines the rate at which neurons of the lemniscal nucleus fire. Thus the response of these neurons is a function of the difference in sound pressure between the two ears.
The time and sound-pressure pathways converge at the lateral shell of the central nucleus of the inferior colliculus. The lateral shell projects to the external nucleus, where each space-specific neuron responds to acoustic stimuli only if the sound originates from a restricted area in space, i.e. the receptive field of that neuron. These neurons respond exclusively to binaural signals containing the same ITD and IID that would be created by a sound source located in the neuron's receptive field. Thus their receptive fields arise from the neurons’ tuning to particular combinations of ITD and IID, simultaneously in a narrow range. These space-specific neurons can thus form a map of auditory space in which the positions of receptive fields in space are isomorphically projected onto the anatomical sites of the neurons.
Significance of asymmetrical ears for localization of elevation
The ears of many species of owls are asymmetrical. For example, in barn owls (Tyto alba), the placement of the two ear flaps (operculi) lying directly in front of the ear canal opening is different for each ear. This asymmetry is such that the center of the left ear flap is slightly above a horizontal line passing through the eyes and directed downward, while the center of the right ear flap is slightly below the line and directed upward. In two other species of owls with asymmetrical ears, the saw-whet owl and the long-eared owl, the asymmetry is achieved by different means: in saw whets, the skull is asymmetrical; in the long-eared owl, the skin structures lying near the ear form asymmetrical entrances to the ear canals, which is achieved by a horizontal membrane. Thus, ear asymmetry seems to have evolved on at least three different occasions among owls. Because owls depend on their sense of hearing for hunting, this convergent evolution in owl ears suggests that asymmetry is important for sound localization in the owl.
Ear asymmetry allows for sound originating from below the eye level to sound louder in the left ear, while sound originating from above the eye level to sound louder in the right ear. Asymmetrical ear placement also causes IID for high frequencies (between 4 kHz and 8 kHz) to vary systematically with elevation, converting IID into a map of elevation. Thus, it is essential for an owl to have the ability to hear high frequencies. Many birds have the neurophysiological machinery to process both ITD and IID, but because they have small heads and low frequency sensitivity, they use both parameters only for localization in the azimuth. Through evolution, the ability to hear frequencies higher than 3 kHz, the highest frequency of owl flight noise, enabled owls to exploit elevational IIDs, produced by small ear asymmetries that arose by chance, and began the evolution of more elaborate forms of ear asymmetry.
Another demonstration of the importance of ear asymmetry in owls is that, in experiments, owls with symmetrical ears, such as the screech owl (Otus asio) and the great horned owl (Bubo virginianus), could not be trained to locate prey in total darkness, whereas owls with asymmetrical ears could be trained.
Facial adaptions for sound localization
The well-developed facial ruff that owls have adapted has shown to help with sound localization as the ruff works to funnel, trap, and focus sounds. The ruff is located around the owl’s face and acts as a reflector for sound. Owls have specific feathers on their head that help direct sound toward their external ear openings, known as reflector feathers, as well as feathers that help prevent the ruff from getting dirty, known as auricular feathers. Reflector feathers sit around the border of the ruff, are very dense, and have been found to help with the ramification of sounds. Auricular feathers, on the other hand, are located around the facial disc of the owl and, unlike reflector feathers, are very loose and do not aid with the ramification of sounds. Owls also have a third type of feather, known as contour feathers, that are found everywhere on the owl’s body except in the facial ruff, but do not at all assist in the ability to localize sounds. Contour feathers are instead useful for things such as flight and conservation of body heat.
Scientists Campenhausen and Wagner performed a study in 2006 on the true relevance of the facial ruff for sound localization. The researchers used five barn owls and studied how well the owls could localize sounds when the facial ruff was completely intact, when the auricular feathers were removed, when the reflector feathers were removed, and when all of the feathers on the head were removed. The owls that had a fully intact facial ruff were able to hear a vast range of sounds very efficiently and with specific directionality. Upon removal of the auricular feathers, the results showed that the owls were not greatly affected, but the range at which the owls could efficiently hear different sounds slightly decreased. When the reflector feathers were removed from the owls, however, the results showed an extreme decrease in both the owls’ hearing range and the directionality of its hearing. When all the feathers were removed from the owls’ heads, the results did not show any major difference in hearing or directionality when compared to the removal of the previous feathers.
This study went further to show that the removal of these kinds of feathers also has an influence on the ITD and ILD in owls’ hearing. The most influential feathers were the reflector feathers, as the removal of these feathers showed to make the owls’ ears more sensitive and selective, and it also extended the physiological range of the ITD. Another study conducted by Hausmann and Campenhausen in 2009 was performed to further confirm the significance of the facial ruff on sound localization in owls.
References
Neuroethology
Hearing
Sound
Owls | Sound localization in owls | [
"Biology"
] | 4,653 | [
"Ethology",
"Behavior",
"Neuroethology"
] |
47,338,588 | https://en.wikipedia.org/wiki/RS%20Coronae%20Borealis | RS Coronae Borealis is a semiregular variable star located in the constellation Corona Borealis with a parallax of 2.93mas being a distance of . It varies between magnitudes 8.7 to 11.6 over 332 days. It is unusual in that it is a red star with a high proper motion (greater than 50 milliarcseconds a year). Located around 1072 light-years distant, it shines with a luminosity approximately 1839 times that of the Sun and has a surface temperature of 3340 K.
In 1907 it was announced that Henrietta Swan Leavitt had discovered the star, then called BD +36° 2672, is a variable star. It was given its variable star designation, RS Coronae Borealis, in 1910.
References
Corona Borealis
Semiregular variable stars
M-type giants
Coronae Borealis, RS
143347
078235
Durchmusterung objects | RS Coronae Borealis | [
"Astronomy"
] | 196 | [
"Corona Borealis",
"Constellations"
] |
47,338,748 | https://en.wikipedia.org/wiki/Nu%20Lyrae | The Bayer designation ν Lyrae is shared by two stars in the constellation Lyra:
ν1 Lyrae (8 Lyrae)
ν2 Lyrae (9 Lyrae), sometimes simply called ν Lyrae
Eridani, Nu
Lyra | Nu Lyrae | [
"Astronomy"
] | 57 | [
"Lyra",
"Constellations"
] |
47,339,067 | https://en.wikipedia.org/wiki/FG-47 | The FG-47 (a.k.a. SpaB-54) is a Chinese solid rocket motor burning HTPB-based composite propellant. It was developed by China Hexi Chemical and Machinery Corporation (also known as the 6th Academy of CASIC) for use in the Long March 2C SD/CTS/SMA third stage. It had its inaugural flight on the Iridium-MFS demonstration mission on September 1, 1997.
It has a total nominal mass of , of which is propellant load. It has an average thrust of with a specific impulse of 288 seconds burning for 35 seconds, with a total impulse of .
See also
CTS
Long March 2C
Iridium deployment
References
Rocket engines of China
Solid-fuel rockets | FG-47 | [
"Astronomy"
] | 154 | [
"Rocketry stubs",
"Astronomy stubs"
] |
47,339,503 | https://en.wikipedia.org/wiki/Weyl%20semimetal | Weyl semimetals are semimetals or metals whose quasiparticle excitation is the Weyl fermion, a particle that played a crucial role in quantum field theory but has not been observed as a fundamental particle in vacuum.
In these materials, electrons have a linear dispersion relation, making them a solid-state analogue of relativistic massless particles.
Theoretical predictions
Weyl fermions are massless chiral fermions embodying the mathematical concept of a Weyl spinor. Weyl spinors in turn play an important role in quantum field theory and the Standard Model, where they are a building block for fermions in quantum field theory. Weyl spinors are a solution to the Dirac equation derived by Hermann Weyl, called the Weyl equation. For example, one-half of a charged Dirac fermion of a definite chirality is a Weyl fermion.
Weyl fermions may be realized as emergent quasiparticles in a low-energy condensed matter system. This prediction was first proposed by Conyers Herring in 1937, in the context of electronic band structures of solid state systems such as electronic crystals. Topological materials in the vicinity of band inversion transition became a primary target in search of topologically protected bulk electronic band crossings.
The first (non-electronic) liquid state which is suggested, has similarly emergent but neutral excitation and theoretically interpreted superfluid's chiral anomaly as observation of Fermi points is in Helium-3 A superfluid phase. Crystalline tantalum arsenide (TaAs) is the first discovered topological Weyl fermion semimetal which exhibits topological surface Fermi arcs where Weyl fermion is electrically charged along the line of original suggestion by Herring. An electronic Weyl fermion is not only charged but stable at room temperature where there is no such superfluid or liquid state known.
Experimental observation
A Weyl semimetal is a solid state crystal whose low energy excitations are Weyl fermions that carry electrical charge even at room temperatures. A Weyl semimetal enables realization of Weyl fermions in electronic systems. It is a topologically nontrivial phase of matter, together with Helium-3 A superfluid phase, that broadens the topological classification beyond topological insulators. The Weyl fermions at zero energy correspond to points of bulk band degeneracy, the Weyl nodes (or Fermi points) that are separated in momentum space. Weyl fermions have distinct chiralities, either left handed or right handed.
In a Weyl semimetal crystal, the chiralities associated with the Weyl nodes (Fermi points) can be understood as topological charges, leading to monopoles and anti-monopoles of Berry curvature in momentum space, which (the splitting) serve as the topological invariant of this phase. Comparable to the Dirac fermions in graphene or on the surface of topological insulators, Weyl fermions in a Weyl semimetal are the most robust electrons and do not depend on symmetries except the translation symmetry of the crystal lattice. Hence the Weyl fermion quasiparticles in a Weyl semimetal possess a high degree of mobility. Due to the nontrivial topology, a Weyl semimetal is expected to demonstrate Fermi arc electron states on its surface. These arcs are discontinuous or disjoint segments of a two dimensional Fermi contour, which are terminated onto the projections of the Weyl fermion nodes on the surface. A 2012 theoretical investigation of superfluid Helium-3 suggested Fermi arcs in neutral superfluids.
On 16 July 2015 the first experimental observations of Weyl fermion semimetal and topological Fermi arcs in an inversion symmetry-breaking single crystal material tantalum arsenide (TaAs) were made. Both Weyl fermions and Fermi arc surface states were observed using direct electronic imaging using ARPES, which established its topological character for the first time. This discovery was built upon previous theoretical predictions proposed in November 2014 by a team led by Bangladeshi scientist M Zahid Hasan.
Weyl points (Fermi points) were also observed in non-electronic systems such as photonic crystals, in fact even before their experimental observation in electronic systems and Helium-3 superfluid quasiparticle spectrum (neutral fermions). Note that while these systems are different from electronic condensed matter systems, the basic physics is very similar.
Crystal growth, structure and morphology
TaAs is the first discovered Weyl semimetal (conductor). Large-size (~1 cm), high-quality TaAs single crystals can be obtained by
chemical vapor transport method using iodine as the transport agent.
TaAs crystallizes in a body-centered tetragonal unit cell with lattice constants a = 3.44 Å and c = 11.64 Å and space group I41md (No. 109). Ta and As atoms are six coordinated to each other. This structure lacks a horizontal mirror plane and thus inversion symmetry, which is essential to realize Weyl semimetal.
TaAs single crystals have shiny facets, which can be divided into three groups: the two truncated surfaces are {001}, the trapezoid or isosceles triangular surfaces are {101}, and the rectangular ones {112}. TaAs belongs to point group 4mm, the equivalent {101} and {112} planes should form a ditetragonal appearance. The observed morphology can be vary of degenerated cases of the ideal form.
Beside the initial discovery of TaAs as Weyl semimetal, many other materials such as Co2TiGe, MoTe2, WTe2, LaAlGe and PrAlGe have been identified to exhibit Weyl semimetallic behavior.
Applications
The Weyl fermions in the bulk and the Fermi arcs on the surfaces of Weyl semimetals are of interest in physics and materials technology. The high mobility of charged Weyl fermions may find use in electronics and computing.
In 2017, a research team from Vienna University of Technology carrying out experimental work to develop new materials, and a team at Rice University carrying out theoretical work, have produced material which they term Weyl–Kondo semimetals.
A group of international researchers led by a team from Boston College discovered in 2019 that the Weyl semimetal Tantalum Arsenide delivers the largest intrinsic conversion of light to electricity of any material, more than ten times larger than previously achieved.
2D Weyl semimetals are spin-polarized analogues of graphene that promise access to topological properties of Weyl fermions in (2+1)-dim spacetime. In 2024, an intrinsic 2D Weyl semimetal with spin-polarized Weyl cones and topological Fermi string edge states was discovered in epitaxial monolayer bismuthene by a team from University of Missouri, National Cheng Kung University, and Oak Ridge National Laboratory.
Further reading
See also
Dirac cone
Dirac matter
Topological insulator
References
Condensed matter physics
Superfluidity | Weyl semimetal | [
"Physics",
"Chemistry",
"Materials_science",
"Engineering"
] | 1,487 | [
"Physical phenomena",
"Phase transitions",
"Phases of matter",
"Materials science",
"Superfluidity",
"Materials",
"Condensed matter physics",
"Exotic matter",
"Semimetals",
"Matter",
"Fluid dynamics"
] |
47,339,585 | https://en.wikipedia.org/wiki/Nu1%20Lyrae | {{DISPLAYTITLE:Nu1 Lyrae}}
Nu1 Lyrae (ν1 Lyrae) is a star in the northern constellation of Lyra. Based upon an annual parallax shift of 2.49 mas as seen from Earth, it is located approximately 1,300 light years from the Sun. At that distance, the visual magnitude of the star is diminished by an extinction factor of 0.35 due to interstellar dust. With an apparent visual magnitude of 5.91, the star is barely bright enough to be visible with the naked eye on a dark night.
This is a blue-white hued B-type subgiant star with a stellar classification of B3 IV. It is a suspected variable. The star has nearly seven times the mass of the Sun and, at an estimated age of about 40 million years, is spinning with a projected rotational velocity of 145 km/s. It radiates approximately 1460 times the solar luminosity from its photosphere at an effective temperature of 14,534 K.
Nu1 Lyrae has four faint visual companions, the nearest being a magnitude 13.0 star at an angular separation of 34.1 arc seconds along a position angle of 76°, as of 2009.
References
B-type subgiants
Lyra
Lyrae, Nu1
Lyrae, 08
092398
092398
7100
Durchmusterung objects | Nu1 Lyrae | [
"Astronomy"
] | 296 | [
"Lyra",
"Constellations"
] |
47,339,689 | https://en.wikipedia.org/wiki/ERCIM%20Cor%20Baayen%20Award | The Cor Baayen Award is an annual award given to a promising young researcher in computer science and applied mathematics.
In 1995, the award was created to honor the first ERCIM (European Research Consortium for Informatics and Mathematics) president.
As a young researcher award, nominees must have obtained their PhD in the three years before the yearly nomination deadline.
A researcher can be nominated for the award only once.
The award is presented as a check for 5000 Euro and a certificate. The awardee is then invited to ERCIM meetings the following autumn.
An article is published in ERCIM news with the name of the winner, and all nominees of the year.
See also
List of computer science awards
List of mathematics awards
References
Computer science awards
Mathematics awards
European awards
Awards established in 1995 | ERCIM Cor Baayen Award | [
"Technology"
] | 160 | [
"Computer science awards",
"Computer science",
"Science award stubs",
"Mathematics awards",
"Science and technology awards"
] |
47,339,901 | https://en.wikipedia.org/wiki/Astris%20%28rocket%20engine%29 | The Astris was a liquid rocket engine burning the hypergolic propellant combination of Aerozine 50 and N2O4. A single engine powered Astris third stage of the failed Europa rocket.
On November 29, 1968, its inaugural flight, the Astris third stage exploded. On the second attempt in July 1969, the Astris engine failed to start. On the third attempt on June 11, 1970, the stage performed correctly, but the fairing failed to separate. On November 5, 1971, the Europa II launched from CSG ELA-1, had a mishap due to structural failure of the third stage. After this last failure the project was definitely cancelled.
See also
Astris (rocket stage)
Europa (rocket)
Viking (rocket engine)
References
Rocket engines using hypergolic propellant
Rocket engines using the pressure-fed cycle | Astris (rocket engine) | [
"Astronomy"
] | 179 | [
"Rocketry stubs",
"Astronomy stubs"
] |
47,340,401 | https://en.wikipedia.org/wiki/Astris%20%28rocket%20stage%29 | The Astris was an upper stage developed by ERNO Raumfahrttechnik GmbH and MBB as the third stage of the Europa 1 launch vehicle. It was the German contribution to the project and only flew activated four times. The high failure rate of the three and four stage rocket meant that the project was cancelled.
On November 29, 1968, its inaugural flight, the Astris third stage exploded. On the second attempt in July 1969, the Astris engine failed to start. On the third attempt on June 11, 1970, the stage performed correctly, but the fairing failed to separate.
On November 5, 1971, the Europa II launched from CSG ELA-1, had a mishap due to structural failure of the third stage. After this last failure the project was definitely cancelled.
Details
The stage measured 3.36 m with a diameter of 2 m, and had an empty mass of 610 kg. Propellant (N2O4/Aerozine-50) mass was 2760 kg, and the single Astris engine produced 23.3 kN of thrust.
See also
Astris (rocket engine)
Europa (rocket)
Viking (rocket engine)
References
Rocket stages | Astris (rocket stage) | [
"Astronomy"
] | 248 | [
"Rocketry stubs",
"Astronomy stubs"
] |
47,340,705 | https://en.wikipedia.org/wiki/Nu2%20Lyrae | {{DISPLAYTITLE:Nu2 Lyrae}}
Nu2 Lyrae, Latinized from ν2 Lyrae, or sometimes simply Nu Lyrae, is a solitary star in the northern constellation of Lyra. Based upon an annual parallax shift of 14.09 mas as seen from Earth, it is located around 231 light years from the Sun. With an apparent visual magnitude of 5.23, it is bright enough to be faintly visible to the naked eye.
This is a white-hued A-type main sequence star with a stellar classification of A3 V. At an estimated age of 214 million years, it is spinning with a projected rotational velocity of 128 km/s. This is giving the star an oblate shape with an equatorial bulge that is 5% larger than the polar radius. Nu2 Lyrae has an estimated 1.9 times the mass of the Sun and about 1.5 times the Sun's radius. It is radiating 32 times the solar luminosity from its photosphere at an effective temperature of around 8,912 K.
References
A-type main-sequence stars
Lyra
Lyrae, Nu2
Lyrae, 09
174602
092405
7102
Durchmusterung objects | Nu2 Lyrae | [
"Astronomy"
] | 262 | [
"Lyra",
"Constellations"
] |
47,340,754 | https://en.wikipedia.org/wiki/Zeta2%20Lyrae | {{DISPLAYTITLE:Zeta2 Lyrae}}
Zeta2 Lyrae is a single, white-hued star in the northern constellation of Lyra. It is a dim star that is just visible to the naked eye with an apparent visual magnitude of 5.74 An annual parallax shift of as seen from Earth provides a distance estimate of about 158 light years from the Sun. It is moving closer to the Sun with a radial velocity of −25 km/s.
This star has a stellar classification of F0 IVn, suggesting it is an F-type subgiant star that is evolving away from the main sequence as its supply of hydrogen at the core has been consumed. The n suffix indicates "nebulous" lines caused by its rotation. It is spinning rapidly with a projected rotational velocity of 212 km/s. This is giving the star an oblate shape with an equatorial bulge that is an estimated 29% larger than the polar radius. The star is radiating approximately 9.6 times the Sun's luminosity from the photosphere at an effective temperature of about . It has 1.7 times the mass of the Sun, twice the Sun's radius, and is about 1.2 billion years old.
It is a suspected variable.
References
F-type subgiants
Lyra
Lyrae, Zeta2
BD+37 3223
Lyrae, 07
173649
091973
7057 | Zeta2 Lyrae | [
"Astronomy"
] | 296 | [
"Lyra",
"Constellations"
] |
47,341,174 | https://en.wikipedia.org/wiki/Collaborative%20diffusion | Collaborative Diffusion is a type of pathfinding algorithm which uses the concept of antiobjects, objects within a computer program that function opposite to what would be conventionally expected. Collaborative Diffusion is typically used in video games, when multiple agents must path towards a single target agent. For example, the ghosts in Pac-Man. In this case, the background tiles serve as antiobjects, carrying out the necessary calculations for creating a path and having the foreground objects react accordingly, whereas having foreground objects be responsible for their own pathing would be conventionally expected.
Collaborative Diffusion is favored for its efficiency over other pathfinding algorithms, such as A*, when handling multiple agents. Also, this method allows elements of competition and teamwork to easily be incorporated between tracking agents. Notably, the time taken to calculate paths remains constant as the number of agents increases.
References
Algorithms | Collaborative diffusion | [
"Mathematics"
] | 180 | [
"Applied mathematics",
"Algorithms",
"Mathematical logic"
] |
47,341,258 | https://en.wikipedia.org/wiki/Data%20janitor | A data janitor is a person who works to take big data and condense it into useful amounts of information. Also known as a "data wrangler", a data janitor sifts through data for companies in the information technology industry. A multitude of start-ups rely on large amounts of data, so a data janitor works to help these businesses with this basic, but difficult process of interpreting data.
While it is a commonly held belief that data janitor work is fully automated, many data scientists are employed primarily as data janitors. The information technology industry has been increasingly turning towards new sources of data gathered on consumers, so data janitors have become more commonplace in recent years.
References
Information science
Computer occupations | Data janitor | [
"Technology"
] | 148 | [
"Computer occupations"
] |
47,341,952 | https://en.wikipedia.org/wiki/Zeta%20Lyrae | The Bayer designation ζ Lyrae (Zeta Lyrae, ζ Lyr) is shared by two stars in the constellation Lyra:
ζ1 Lyrae (6 Lyrae), an Am star
ζ2 Lyrae (7 Lyrae), an F0 subgiant
They form a double star with an angular separation of .
References
Lyrae, Zeta
Lyra | Zeta Lyrae | [
"Astronomy"
] | 82 | [
"Lyra",
"Constellations"
] |
49,072,694 | https://en.wikipedia.org/wiki/Architectural%20coatings | Architectural coatings or paints are paints and other coatings used to paint the exteriors and interiors of buildings, often called or external masonry coatings. Clear varnishes and lacquers are generally excluded. Such products are usually designated for specific purposes such as roof coatings, wall paints, or deck finishes. Coatings are eco-friendly building material that increases the efficiency of energy used and reduces impact on human well-being and the environment. The coatings are typically applied with brushes, rollers or sprayers.
Wall coatings come in a variety of types, some of which can be applied by amateurs and DIYers without specialized training or equipment. For example, simple paint or primers can often be applied using brushes or rollers, and many people successfully complete such projects themselves. Most masonry surfaces can be treated an exterior wall coating, such as render, pebbledash, stone, stucco or brick. Most coatings are designed to be microporous in nature, allowing captive moisture within the wall to evaporate outside, whilst not allowing the passage of water to be drawn inside the building, thus largely providing a secondary feature apart from decoration, and that is to weatherproof a wall, and to stop damp forming inside the building. These coatings are intended for on-site application and do not include "factory-applied coatings for building products such as vinyl siding or aluminium window frames [that] may ultimately be used for architectural end-uses".
See also
Industrial coating
References
Coatings
Painting materials
Architectural terminology | Architectural coatings | [
"Chemistry",
"Engineering"
] | 310 | [
"Architectural terminology",
"Coatings",
"Architecture"
] |
49,073,376 | https://en.wikipedia.org/wiki/Extinct%20isotopes%20of%20superheavy%20elements | Extinct isotopes of superheavy elements are isotopes of superheavy elements whose half-lives were too short to have lasted through the formation of the Solar System, and because they are not replenished by natural processes, can nowadays only be found as their decay products (from alpha decay, cluster decay or spontaneous fission) trapped within sediment and meteorite samples dating billions of years ago.
Carbonaceous chondrite fission xenon
Carbonaceous chondrite fission xenon (CCF Xe), are a collection of different isotopes of xenon that were thought to have arisen from the decay of a superheavy element within the island of stability. Early studies proposed that the half life of the theoretical progenitor of CCF Xe to be on the order of 10 years. A later attempt at characterization of the progenitor in 1975 by Edward Anders, a professor of chemistry at the University of Chicago, and colleague John Larimer suggested a heat of vaporization of 54 kJ/mol and a boiling point of 2500K for the element and, based on estimated accretion temperatures, they also proposed elements 111 and 115 (today named roentgenium and moscovium) as the most likely candidates assuming the element condensed in pure form.
Allende meteorite
Anders went on to study samples of the Allende meteorite, the largest carbonaceous chondrite ever found on Earth. Results of these studies suggested elements 111–115 (today roentgenium, copernicium, nihonium, flerovium, and moscovium) as the most likely candidates for the progenitor of CCF Xe. These studies also proposed that the progenitor condensed as an iron chromium sulfide. This was later called into question as iron chromium sulfide is very rare with a relative abundance of 0.4%.
Evidence against carbonaceous fission xenon
By the 1980s, CCF Xe actually being the product of fission was doubtful, and the alternate theory that it had arisen from r-process (neutron capture) nucleosynthesis gained more ground. Researchers looked at the isotopic anomalies in nearby elements samarium, neodymium, and barium, and compared to the amount of xenon. Whether CCF Xe was produced by nucleosynthesis or fission, comparable amounts of barium-135 should be produced. When researchers compared the experimental data to predicted amounts of Barium following each model, neither model came close to predicting the anomalies correctly, leading to Lewis et al. calling the experiment an "embarrassment" for both models. However, in the case of nucleosynthesis, it is possible that samarium, neodymium, and barium were separated from Xe by prior condensation in the supernova shell or plasma processes. Based on this data it was deemed unlikely that CCF Xe had actually arose from fission.
References
Environmental isotopes
Hypothetical chemical elements
Radioactivity
Nuclear fission
Geological history of Earth
Geology theories
Xenon | Extinct isotopes of superheavy elements | [
"Physics",
"Chemistry"
] | 632 | [
"Nuclear fission",
"Environmental isotopes",
"Isotopes",
"Nuclear physics",
"Radioactivity"
] |
49,073,441 | https://en.wikipedia.org/wiki/Oxidative%20dissolution%20of%20silver%20nanoparticles | Silver nanoparticles (AgNPs) act primarily through a process known as oxidative dissolution, wherein Ag+ ions are released through an oxidative mechanism. AgNPs have potentially vast applications within the fields of medicine, science, and food and drug industries due to their antimicrobial properties, low cytotoxicity in humans, and inexpensive cost.
Mechanism
Silver is stable in water and needs an oxidizing element to achieve oxidative dissolution. When oxidizing agents such as hydrogen peroxide or oxygen are present, they dissolute AgNPs to release Ag+. The release of Ag+ leads to creation of reactive oxygen species (ROS) inside cells, which can further dissolute the nanoparticles. Some nano silver particles develop protective Ag3OH surface groups and it is thought that dissolution removes these groups and forms oxygen radicals, which attenuate reactivity of the AgNPs by entering into the lattice to form a highly stable Ag6O octahedral structure. It has been thought AgNP efficacy can mainly be attributed to shape, as nanoprisms and naorods have proven more active than nanospheres because they possess more highly exposed facets, thus leading to a faster release of Ag+ ions.
Environmental factors
Environmental factors that play a role in particle dissolution:
pH (rate increases with increasing pH ( 6–8.5)),
presence of halide ions (cause Ag+ precipitation),
particle coating
presence of reducing sugars.
The presence of cysteine (inhibits dissolution).
presence of natural organic matter.
Synthesis
AgNPs are synthesized using microwave irradiation, gamma irradiation UV activation, or conventional heating of the precursor silver nitrate, AgNO3 using an alginate solution as a stabilizing and reducing agent. The carboxyl or hydroxyl groups on the alginate reagent form complexes during the synthesis of the AgNPs that stabilize the reaction. Nanoparticle size and shape can be specified by changing the ratio of alginate to silver nitrate used and/or the pH. A coating such as PVP may be added to the nanoparticles by heating and subsequent slow cooling.
Kinetics
Stopped-flow spectrometry has been used to characterize the chemical mechanism and kinetics of AgNPs. Oxidative dissolution of AgNPs has been shown to be a first order reaction with respect to both silver and hydrogen peroxide and is independent of particle size.
Antimicrobial activity
Antibacterial, antiviral and anti-fungal properties have been investigated in response to AgNP dissolution. Antibacterial activities of AgNPs are much stronger in oxygenic conditions than anoxic conditions. Through their oxidative dissolution in biological systems, AgNPs can target important biomolecules such as “DNA, peptides, and cofactors” as well as absorb into nonspecific moieties and simultaneously disrupt several metabolic pathways. They have been known to act as a bridging agent between thiols, to have affinity for organic amines and phosphates. The combination of silver ions’ reaction with biomolecules with oxidative stress, ultimately leads to toxicity in biological environment.
Inhibition of nitrification
Oxidative dissolution of AgNPs, which gives rise to Ag+, potentially inhibits nitrification within Ammonia oxidizing bacteria. A key step in nitrification is the oxidation of ammonia to hydroxylamine (NH2OH) catalyzed by the enzyme ammonia monooxyganase (AMO). The enzymatic activity of AMO is highly vulnerable to interference due to its intracytoplasmic location and its abundance of copper. It is speculated that Ag+ ions from AgNPs interfere with AMO's copper bonds by replacing copper with Ag+ causing a decrease in enzymatic activity, and thus nitrification.
References
Nanoparticles by composition
Chemical reactions
Silver | Oxidative dissolution of silver nanoparticles | [
"Chemistry"
] | 826 | [
"nan"
] |
49,076,198 | https://en.wikipedia.org/wiki/Lactarius%20xanthogalactus | Lactarius xanthogalactus, commonly known as the yellow-staining milkcap is a species of fungus in the family Russulaceae. Several other Lactarius species that bear resemblance to L. xanthogalactus, but most can be distinguished by differences in staining reactions, macroscopic characteristics, or habitat.
The species is found on the west coast of the United States and grows in the ground under trees.
Taxonomy and classification
The species was first described by American mycologist Charles Horton Peck in 1907.
The specific epithet xanthogalactus is derived from the Greek words meaning "yellow" and "milk".
Description
The species produces mushrooms with pinkish-cinnamon caps measuring wide held by pinkish-white stems long and wide. When it is cut or injured, the mushroom oozes a white latex that rapidly turns bright sulfur-yellow. The spores are pale yellow, elliptical and bumpy. The spore print is pale yellow. The mushroom has an unpleasant taste.
Similar species
Lactarius vinaceorufescens has nearly identical microscopic features to L. xanthogalactus, but macroscopically it has reddish-vinaceous stains that develop on the cap, gills, and stem. Another lookalike is L. colorascens, but it may be distinguished from L. xanthogalactus by several features: a smaller fruit body; a whitish cap that becomes brownish-red with age and does not spot vinaceous or brown; bitter to faintly acrid latex; and slightly smaller spores. L. chrysorrheus is also similar, but it has a whitish to pale yellowish-cinnamon cap with slightly darker spots and grows under hardwoods (especially oak) on well-drained, often sandy soil, and its gills do not discolor or spot vinaceous or brown.
Other superficially similar species include L. rubrilacteus, L. rufus, L. subviscidus, L. fragilis and L. rufulus, but none of these species have the yellow staining reaction characteristic of L. xanthogalactus. It could also be mistaken with L. rubidus, which is redder and sweet smelling, and L. substriatus, which has a red-orange cap and white latex that yellows.
Habitat and distribution
The fruit bodies grow scattered or in groups on the ground under conifers and hardwoods between November and February in Oregon and California.
See also
List of Lactarius species
References
xanthogalactus
Fungi described in 1907
Fungi of the United States
Taxa named by Charles Horton Peck
Fungi without expected TNC conservation status
Fungus species | Lactarius xanthogalactus | [
"Biology"
] | 544 | [
"Fungi",
"Fungus species"
] |
49,076,334 | https://en.wikipedia.org/wiki/Ti-6Al-7Nb | Ti-6Al-7Nb (UNS designation R56700) is an alpha-beta titanium alloy first synthesized in 1977 containing 6% aluminum and 7% niobium. It features high strength and has similar properties as the cytotoxic vanadium containing alloy Ti-6Al-4V. Ti-6Al-7Nb is used as a material for hip prostheses.
Ti―6Al―7Nb is one of the titanium alloys that built of hexagonal α phase (stabilised with aluminium) and regular body-centred phase β (stabilised with niobium). The alloy is characterized by added advantageous mechanical properties, it has higher corrosion resistance and biotolerance in relation to Ti-6Al-4V alloys.
Physical properties
Physical properties of the alloy are mostly dependent on the morphology and the fractions volume of the phases presence from the parameters obtained from the manufacturing process.
As shown in the above table, alloying is one of the effective methods to improve the mechanical properties and since Niobium belongs to the same group of Vanadium in the periodic table it is of course acts as α –β stabilizing elements (similar to Ti-6Al-4V alloy), however the strength of Nb alloy is little less than that of Ti-6Al-4V .The main difference between Ti-6Al-4V and Ti-6Al-7Nb is related to different factors such as solid-solution strengthening, the structure-refining strengthening provided by the refined two-phase structure and the difference in the microstructure between the two alloys.
Production
Ti-6Al-7Nb is produced by powder metallurgy methods. The most common methods are hot pressing, metal injection mouldering and blending and pressing. In the production of Ti-6Al-7Nb, usually a sintering temperature between 900-1400o C is used. Altering the sintering temperature gives the Ti-6Al-7Nb different properties such as different porosity and microstructure. It also gives a different composition between alpha, beta and alpha+beta phases. In the recent years Ti-6Al-7Nb alloys could also be made by different 3D-printer technique such as SLM and EBM.
Heat treatment
Heat treatment of titanium is demonstrated to have significant influences on reducing the residual stresses, improving the mechanical properties (i.e. tensile strength or fatigue strength by solution treatment and ageing). Moreover, heat treatment provides an ideal combination of ductility, machinability and structural stability due to the differences in microstructure and cooling rates between α and β phases.
The cooling rate have an impact of the morphology . When the cooling rate is reduced for example from air cool to slow cooling, the morphology of the transformed α increases in thickness and length and is contained within fewer, larger α colonies. The α colony size is the most important microstructural properties due to its influences the fatigue properties and deformation mechanics of β processed α+ β alloys.
Applications
Implant devices replacing such as : failed hard tissue, artificial hip joints, artificial knee joints, bone plates, screws for fracture fixation, cardiac valve prostheses, pacemakers, and artificial hearts.
Dental application
Biocompatibility
Ti-6Al-7Nb has a high biocompatibility. The oxides from Ti-6Al-7Nb is saturated in the body and are not transported in vivo or are a bioburden. The alloy will not create adverse tissue tolerance reactions and creates fewer giant cell nuclei. Ti-6Al-7Nb also shows a high compatibility to ingrowth to the human body.
Specification
Designations for Ti-6Al-7Nb in other naming conventions include:
UNS: R56700
ASTM Standard: F1295
ISO Standard: ISO 5832-11
References
Further reading
Biomaterials
Titanium alloys | Ti-6Al-7Nb | [
"Physics",
"Chemistry",
"Biology"
] | 803 | [
"Biomaterials",
"Titanium alloys",
"Materials",
"Alloys",
"Matter",
"Medical technology"
] |
49,076,898 | https://en.wikipedia.org/wiki/Liquidity%20at%20risk | The Liquidity-at-Risk (short: LaR) is a measure of the liquidity risk exposure of a financial portfolio.
It may be defined as the net liquidity drain which can occur in the portfolio in a given risk scenario. If the Liquidity-at-Risk is greater than the portfolio's current liquidity position then the portfolio may face a liquidity shortfall.
Liquidity-at-Risk is different from other measures of risk based on total loss, as it is based on an estimate of cash losses, or liquidity outflows, as opposed to total loss.
Definition
The Liquidity-at-Risk of a financial portfolio associated with a stress scenario is the net liquidity outflow resulting from this stress scenario:
The liquidity shortfall in a stress scenario is thus given by the difference between the Liquidity-at-Risk associated with the stress scenario and the amount of liquid assets available at the point where the scenario occurs.
The concept of Liquidity-at-Risk is used in stress testing. It is a conditional measure, which depends on the stress scenario considered.
By analogy with Value-at-Risk one may also define a statistical notion of Liquidity-at-Risk, at a given confidence level (e.g. 95%), which may be defined as the highest Liquidity-at-Risk that may occur across all scenarios considered under a probabilistic model, with probability higher than the confidence level.
This statistical notion of Liquidity-at-Risk is subject to model risk as it will depend on the probability distribution over scenarios.
Relation with other risk measures
Liquidity-at-Risk is different from other measures of risk based on total loss, such as Value-at-Risk, as it is based on an estimate of cash losses, or liquidity outflows, as opposed to total loss.
See also
Margin at risk
Value at risk
Profit at risk
Earnings at risk
Cash flow at risk
References
Mathematical finance
Financial risk modeling
Monte Carlo methods in finance | Liquidity at risk | [
"Mathematics"
] | 408 | [
"Applied mathematics",
"Mathematical finance"
] |
49,077,978 | https://en.wikipedia.org/wiki/C3H5O3 | {{DISPLAYTITLE:C3H5O3}}
The molecular formula C3H5O3 (molar mass: 89.07 g/mol) may refer to:
Etabonate group : CH3-CH2-O-CO-O-
Lactate anion, found in salts and solutions of lactic acid | C3H5O3 | [
"Chemistry"
] | 73 | [
"Isomerism",
"Set index articles on molecular formulas"
] |
49,078,162 | https://en.wikipedia.org/wiki/Sufotidine | Sufotidine (INN, USAN, codenamed AH25352) is a long-acting competitive H2 receptor antagonist which was under development as an antiulcerant by Glaxo (now GlaxoSmithKline). It was planned to be a follow-up compound to ranitidine (Zantac). When taken in doses of 600 mg twice daily it induced virtually 24-hour gastric anacidity thus closely resembling the antisecretory effect of the proton pump inhibitor omeprazole. Its development was terminated in 1989 from phase III clinical trials based on the appearance of carcinoid tumors in long-term toxicity testing in rodents.
Synthesis
See also
Lavoltidine (previously known as loxtidine) — a similar compound in which methylsulfone group is replaced with hydroxyl
References
Abandoned drugs
Amines
H2 receptor antagonists
1-Piperidinyl compounds
Triazoles
Phenol ethers
Sulfones | Sufotidine | [
"Chemistry"
] | 206 | [
"Drug safety",
"Functional groups",
"Sulfones",
"Amines",
"Bases (chemistry)",
"Abandoned drugs"
] |
49,079,483 | https://en.wikipedia.org/wiki/Planetary%20Defense%20Coordination%20Office | The Planetary Defense Coordination Office (PDCO) is a planetary defense organization established in January 2016 within NASA's Planetary Science Division of the Science Mission Directorate. It includes a Near Earth Observations Program which funds telescopic searches and orbit calculations.
Its mission is to look for and catalogue near-Earth objects such as comets, asteroids, and potentially hazardous objects that could impact Earth, as well as help the U.S. government prepare for a potential impact event (and coordinate efforts to mitigate and deflect potential threats if one is detected).
History
In 2005, the U.S. Congress passed the NASA Authorization Act, which, in part, tasked NASA with finding and cataloguing at least 90% of all near-Earth objects that are 140 meters or larger by 2020. However, that goal was clearly not being met by NASA's Near Earth Object Observations Program, which a 2014 report by the NASA Office of Inspector General pointed out. In June 2015, NASA and National Nuclear Security Administration of the U.S. Department of Energy, which had been studying impact events on their own, signed an agreement to work in cooperation.
In January 2016, NASA officially announced the establishment of the Planetary Defense Coordination Office (PDCO), appointing Lindley Johnson to lead it as Planetary Defense Officer. The PDCO was given the job of cataloging and tracking potentially hazardous near-Earth objects (NEO), such as asteroids and comets, larger than 30–50 meters in diameter (compare to the 20-meter Chelyabinsk meteor that exploded over Russia in 2013) and coordinating an effective threat response and mitigation effort.
It has been a part of several key NASA missions, including OSIRIS-REx, NEOWISE, and Double Asteroid Redirection Test (DART). For NEOWISE, NASA worked with the Jet Propulsion Laboratory, to investigate various impact-threat scenarios in order to learn the best approach to the threat of an incoming impactor. The office would continue to use the polar orbiting infrared telescope NEOWISE, decommissioned in August 2024, to detect any potentially hazardous objects.
Double Asteroid Redirection Test (DART), a joint project between NASA and the Johns Hopkins Applied Physics Laboratory, is the first planetary defense mission of NASA. In November 2021, the DART spacecraft was launched with the goal of seeing if it could "alter an asteroid's path, a technique that may be used to defend the planet in the future". The attempt was successful.
In popular culture
The 2021 movie Don't Look Up is about a "planet killer" comet, in which the Planetary Defense Officer is played by Rob Morgan. PDCO chief Lindley Johnson vetted an early draft of the screenplay over two years before the film's 2021 release.
See also
Asteroid impact avoidance
Don't Look Up (2021 film)
Double Asteroid Redirection Test
Impact event
Spaceguard
References
External links
NASA’s New Planetary Defense Office, planetary.org
https://www.nasa.gov/specials/pdco/index.html,
Planetary defense organizations
NASA | Planetary Defense Coordination Office | [
"Astronomy"
] | 618 | [
"Planetary defense organizations",
"Astronomy organizations"
] |
49,079,889 | https://en.wikipedia.org/wiki/NFL%20uniform%20numbers | Players in the National Football League (NFL) wear uniform numbers between 0 and 99, with no two players on a team able to wear the same number outside of the offseason. Rules exist which tie a player's number to a specific range of numbers for their primary position. Additionally, rules exist which limit who may handle the ball on offense: generally players who are designated as offensive linemen, who wear numbers 50–79, are not allowed to handle the ball during a play from scrimmage, though they are allowed to do so if they report to the referee as playing out of position for a tackle-eligible play, if they pick up a fumble, or if they catch a deflected pass.
History
Prior to 1973
The earliest numbering systems were significantly different from the modern variation. Until the 1920s, when the NFL limited its rosters to 22 players, it was rare to see player numbers much higher than 25 (Red Grange was a notable exception, wearing 77 with the Chicago Bears while playing halfback, which would not be allowed under current NFL rules), and numbers had little correlation with positions (in 1929, the Orange Tornadoes subverted the system even further, experimenting with using letters instead of numbers).
The numbering system used today originated when all teams employed some variation of the single wing formation on offense. When teams switched to the T-formation in the 1930s and 1940s, the numbers were taken with them to whichever position evolved from the old single wing position. This numbering system originated in college football and was used only informally in the NFL until 1952; the backs were given numbers in the 10–49 range and the offensive line numbers in the 50–89 range. Earlier, defensive players wore numbers that reflected their offensive position, as many players played both offense and defense. For example, quarterbacks and halfbacks usually played in the defensive back field and so had numbers in the 10–49 range, defensive line numbers ranged from 50–89, while linebackers (who often played fullback or tight end on offense) could have just about any number. Split ends (precursors to modern wide receivers) had numbers in the 80s, and many would play cornerback (e.g., Night Train Lane, who wore 81 as a cornerback).
The All-America Football Conference (AAFC) of the 1940s, which later merged with the NFL, had a different numbering system with quarterback in the 60–69 range (Otto Graham), fullbacks in the 70–79 range (Marion Motley), halfbacks in the 80–89 (Don Greenwood) and 90–99 range (Tommy Colella), ends in the 50–59 range (Mac Speedie), tackles in the 40–49 range (Lou Groza), guards in the 30–39 range (Bill Willis), and centers in the 20–29 range (Frank Gatski). When the AAFC merged with the NFL in 1950, the AAFC players kept their old uniform numbers, which caused confusion and resulted in the NFL going to a standard numbering system in 1952. This resulted in many star players having to change their numbers mid-career. Examples are Otto Graham going from 60 to 14, Norm Van Brocklin going from 25 to 11, Marion Motley going from 76 to 36, and Tom Fears going from 55 to 80.
The American Football League (AFL) of the 1960s, which also later merged with the NFL, used essentially the same numbering system as the NFL with some exceptions, mostly pertaining to wide receivers, who were allowed to wear numbers in the teens and 20s (as the AFL had a greater priority toward offense, the league often made use of flankers, receivers positioned in the backfield). The AFL's numbering system also allowed for the use of a double-zero as a number, which was used by future Hall of Fame player Jim Otto, center for the Oakland Raiders; after wearing the number 50 in his rookie season, he switched to 00 (which was said as 'aught, oh', a homonym of Otto), which he wore for the remainder of his career.
1973 standardization
The NFL imposed a more rigid numbering system in 1973. When it went into effect, players who had played in the league before the 1973 season were given a grandfather clause to continue wearing their now-prohibited numbers. Pro Football Hall of Fame wide receiver Charlie Joiner was the last player covered by the clause, wearing number 18 through the 1986 NFL season, after which he retired (Under the current jersey system, Joiner's #18 would have been allowed for a Wide receiver to wear). Joiner was the last active player who began his career in the AFL. The last player to be grandfathered who wore a number that would not have been allowed under the current jersey system was Julius Adams, who retired in 1985 wearing the number 85 as an Defensive End, although Adams did return to play in 1987 wearing the number #69.
1973–2020
From 1973 to 2020, five major changes were made. In 1979, the NFL allowed defensive linemen to wear numbers 90–99 and centers 60–79. In 1984, the NFL allowed linebackers to wear jersey numbers in the 90–99 range, since more teams were making use of the 3–4 defense and thus were quickly exhausting numbers for linebackers, who previously were only allowed to wear numbers in the 50–59 range. Another change occurred in 2004, when the NFL allowed wide receivers to wear numbers 10–19 in addition to the previous 80–89 range; this was due to several NFL teams retiring 80-range numbers, as well as teams employing more receivers and tight ends in their offense. Since 2010, defensive linemen are allowed to wear numbers 50–59; this is in part because of the interchangeability of linebackers and defensive ends (a defensive end in a 4–3 defense would be an outside linebacker in a 3–4 defense). In 2015, the NFL Competition Committee allowed linebackers to wear numbers from 40–49.
2021–2023 expansions
In 2021, NFL owners passed a rule expanding available numbers and simplifying the numbering system. The system had three different number groupings for offense and three for defense. The changes included the addition of numbers 1–19 and 80–89 for running backs, 1–9 and 20–49 for wide receivers, 1–39 for tight ends and linebackers, and 1–19 for defensive backs. In 2023, a playing rule was passed allowing players to wear the jersey number 0, and kickers and punters were given eligibility to use numbers 20–49 and 90–99.
Current system
The numbers used relate to the player's primary position when they are first assigned a number. If they later change positions, they can keep their prior number, provided they have spent at least one season at their original position, unless it conflicts with the eligible receiver rule; that is, only players that change positions from an eligible position (such as receiver or back) to an ineligible position (such as an offensive lineman) are required to change numbers if they change position. An example of this is running back Ty Montgomery, who wore number 88 throughout his NFL career because he began his career as a wide receiver. Devin Hester is another example; he was originally drafted as a cornerback and was allowed to keep his number 23 when he converted to a wide receiver. Some receivers have worn jersey numbers in the nineties such as Mike Ditka wearing 98 for the Philadelphia Eagles and Keith Ortego wearing 96 for the Chicago Bears.
Additionally, during a game a player may play out-of-position, but only after reporting in to the officials, who will announce to the stadium that a specific player number has reported in (for example, "Number 61 has reported as an eligible receiver") to alert the opposing team, other officials, and the audience that a player is legally out-of-position. A 2015 rule clarification made it illegal to use unusual formations (such as a tackle split wide in the slot position, but still "covered" by a wide receiver) to obscure who is and is not eligible based on uniform numbers without having to report ineligible numbers.
Long snappers typically will wear 40–59, with some exceptions. Long snappers, despite being an official roster position, do not have an official rule for their numbers in the rule book.
The rulebook also allows players to appeal for exemptions to the numbering rules directly to the commissioner's office, which may grant such exceptions on occasion.
Retired numbers
Many NFL teams have retired some numbers in honor of the team's best players. Generally when a number is retired, future players for the team may not wear it. The NFL officially discourages (but does not prevent) teams from retiring numbers, as the limited number of uniform numbers available for each position can be depleted. Some teams will hold official "number retirement" ceremonies, others have "informally" retired numbers by simply not issuing them. For teams that do not retire uniform numbers, they often honor players in other ways, such as team halls of fame or the like.
Numbers 0 and 00
Following the NFL number standardization of 1973, numbers 0 and 00 were no longer eligible to be issued by teams. Prior to the 1973 standardization, some players had made occasional use of both 0 and 00. Quarterback Johnny Clement, running back Johnny Olszewski, and safety Obert Logan all wore a single-0 jersey in the NFL. Author George Plimpton wore 0 during a brief preseason stint at quarterback for the Detroit Lions. Linebacker Bryan Cox wore 0 in the 2001 preseason with the New England Patriots; for the regular season, he switched to 51. In addition to Jim Otto, wide receiver Ken Burrough of the Houston Oilers and halfback Steve Bagarus of the Washington Redskins and Los Angeles Rams also wore the number 00 during their NFL careers. The three of them remain the only NFL players to have ever worn 00.
Starting with the 2023 season, the number 0 was once again allowed to be issued to any player except offensive and defensive linemen. Notable players who switched to number 0 include running back D'Andre Swift of the Philadelphia Eagles, wide receiver Calvin Ridley of the Jacksonville Jaguars, and linebacker Roquan Smith of the Baltimore Ravens. In all, 12 players chose to don number 0 in 2023. The number 00 remains prohibited.
References
Uniform numbering
Football, American NFL | NFL uniform numbers | [
"Mathematics"
] | 2,116 | [
"Numbering in sports",
"Mathematical objects",
"Numbers"
] |
49,082,005 | https://en.wikipedia.org/wiki/HD%20133002 | HD 133002 (HR 5596) is a possible binary star in the northern constellation of Ursa Minor. With an apparent visual magnitude of 5.65, it is faintly visible to the naked eye. (According to the Bortle scale, it can be viewed from dark rural skies.) The high declination of +82.5° means it is hidden from view from most of the southern hemisphere. Parallax measurements yield an estimated distance of around 142 light years from the Sun. If it was instead positioned at a distance of , this would be a second magnitude star. The system is drifting closer with a heliocentric radial velocity of −44 km/s.
This is a G-type main sequence star with a stellar classification of G2V, although it has also been classified as F9V or G0V. With spectral absorption lines of metals and absorption bands of some molecules weaker than expected based on its hydrogen lines, it is defined as a weak line star. Based on its G-band strengths, it would we given a class of G0, and based on its metal lines a class of G1.
It is estimated to have 51% greater mass than the Sun, and is younger with an age of around 2.8 billion years. The projected rotational velocity along the star's equator is a relatively leisurely 5.2 km/s. The star is considered a photometric solar analog, although it is deficient in elements more massive than helium when compared to the Sun. The chemical composition and relatively low surface gravity for a star of its classification suggest that this may instead be a subgiant star that is in the process of evolving away from the main sequence. The effective temperature of the star's photosphere is , giving it the yellow-white hue of a G-type star.
This star has been examined for evidence of an infrared excess, but none was detected. During a 2006−2007 survey of nearby stars, it was discovered that HD 133002 has a low-mass common proper motion stellar companion. This object has an estimated 15% of the Sun's mass. It has a projected separation of around 80 AU from the primary, which suggests an orbital period of roughly 700 years. At present, there is insufficient observational data available to determine orbital elements.
References
G-type main-sequence stars
Ursa Minor
5596
Durchmusterung objects
3876
133002
072573 | HD 133002 | [
"Astronomy"
] | 505 | [
"Ursa Minor",
"Constellations"
] |
49,083,018 | https://en.wikipedia.org/wiki/Grimace%20scale | The grimace scale (GS), sometimes called the grimace score, is a method of assessing the occurrence or severity of pain experienced by non-human animals according to objective and blinded scoring of facial expressions, as is done routinely for the measurement of pain in non-verbal humans. Observers score the presence or prominence of "facial action units" (FAU), e.g. Orbital Tightening, Nose Bulge, Ear Position and Whisker Change. These are scored by observing the animal directly in real-time, or post hoc from photographs or screen-grabs from videos. The facial expression of the animals is sometimes referred to as the pain face.
The GS method of pain assessment is highly applicable to laboratory rodents as these are usually prey species which tend to inhibit the expression of pain to prevent appearing vulnerable to predators. For this reason, behavioural changes in these species are mainly observed with acute pain (hours) but are less pronounced in longer-lasting pain (days).
For mice at least, the GS has been shown to be a highly accurate, repeatable and reliable means of assessing pain requiring only a short period of training for the observer. Across species, GS are proven to have high accuracy and reliability, and are considered useful for indicating both procedural and postoperative pain, and for assessing the efficacy of analgesics.
The overall accuracy of GS is reported as 97% for mice, 84% for rabbits, 82% for rats and 73.3% for horses.
History
Facial expressions have long been considered as indicators of emotion in both human and non-human animals. The biologist Charles Darwin considered that non-human animals exhibit similar facial expressions to emotional states as do humans. The assessment of changes in human anatomy during facial expressions were successfully translated from humans to non-human primates, such as the chimpanzee (ChimpFACS) and rhesus macaque (MaqFACS), but were not originally applied to assess pain in these species. In 2010, a team of researchers successfully developed the first method to assess pain using changes in facial expression in any non-human animal species. Broadly speaking, GS quantify spontaneous pain according to objective and blinded scoring of facial expressions, as is done routinely for the measurement of pain in non-verbal humans. Observers score the presence and extent of "facial action units" (FAU), e.g. Orbital Tightening, Nose Bulge, Ear Position and Whisker Change. These are scored in real-time by observing the animal directly, or, post hoc from photographs or screen-grabs from videos.
This method of pain assessment is highly applicable to prey animals which tend to inhibit the overt expression of pain to prevent appearing vulnerable to predators. For this reason, behavioural changes in these species are mainly observed with acute pain (hours) but are less pronounced in longer-lasting pain (days).
GS offer advantages over other methods of pain assessment. For example, the analgesic morphine reduces pain but can affect other aspects of behaviour in pain-free animals, for example, excitement, increased activity or sedation, which can hamper traditional behavioural assessment of its action on pain. Morphine not only reduces the frequency of "pain faces" but has no effect on GS in baseline, pain-free mice.
In mice
The GS for mice usually consists of five FAU, i.e. Orbital Tightening, Nose Bulge, Cheek Bulge, Ear position and Whisker Change. These are scored on a 0-2 scale where 0=the criterion is absent, 1=moderately present and 2=obviously present. In mice, the GS offers a means of assessing post-operative pain that is as effective as manual behavioural-based scoring, without the limitations of such approaches.
Facial grimacing by mice after undergoing laparotomy surgery indicates postoperative pain lasts for 36 to 48 h (and at relatively high levels for 8 to 12 h) with relative exacerbation during the early dark (active) photo-phase. Furthermore, the grimacing indicates that buprenorphine is fully efficacious at recommended doses against early postoperative pain, but carprofen and ketoprofen are efficacious only at doses much higher than currently recommended: acetaminophen is not efficacious.
A study in 2014 examined postoperative pain in mice following surgical induction of myocardial infarction. The effectiveness of the GS at identifying pain was compared with a traditional welfare scoring system based on behavioural, clinical and procedure-specific criteria. It was reported that post hoc GS (but not real-time GS) indicated a significant proportion of the mice were in low-level pain at 24 h which were not identified as such by traditional assessment methods. Importantly, those mice identified as experiencing low-level pain responded to analgesic treatment, indicating the traditional methods of welfare assessment were insensitive in this aspect of pain recognition.
Mice with induced sickle cell disease and their controls exhibited a "pain face" when tested on a cold plate, but sickle mice showed increased intensity compared to controls; this was confirmed using Von Frey filaments a traditional method of pain assessment. GS have also been used to assess pain and methods of its alleviation in pancreatitis.
GS have also been used to test the degree of pain caused as a side-effect of therapeutic drugs and methods of mitigating the pain.
The mouse GS has been shown to be a highly accurate, repeatable and reliable means of assessing pain, requiring only a short period of training for the observer. Assessment approaches that train deep neural networks to detect pain and no-pain images of mice may further speed up MGS scoring, with an accuracy of 94%.
Sex and strain effects
It has been noted that DBA/2 strain mice, but not CBA strain mice, show an increase in GS score following only isoflurane anaesthesia, which should be taken into account when using the GS to assess pain. Administration of a common analgesic, buprenorphine, had no effect on the GS of either strain.
There are interactions between the sex and strain of mice in their GS and also the method that is used to collect the data (i.e. real-time or post hoc), which indicates scorers need to consider these factors.
Effects of non-painful procedures
It is important to establish whether methods of pain assessment in laboratory animals are influenced by other factors, especially those which are a normal part of routine procedures or husbandry. There is no difference in GS scores between mice handled using a tube compared with mice picked up by the tail, indicating these handling techniques are not confounding factors in GS assessment. A similar study reported there was no difference between GS scores at baseline and immediately post ear notching (a method frequently used to identify laboratory mice), potentially indicating that the pain associated with ear notching is either too acute to assess using the GS tool or the practice is not painful.
In rats
There are differences between the "pain face" of mice and rats. In mice, the nose and cheek at baseline have a smooth appearance, but in the presence of pain, change to distinct bulges in both the nose and cheek regions. By contrast, in rats at baseline, the nose and cheek regions show distinct bulging, and with pain, the bridge of the nose flattens and elongates, causing the whisker pads to flatten. As a consequence of these differences, the GS for rats sometimes use four FAU, i.e. Orbital Tightening, Nose/Cheek Flattening, Ear Changes and Whisker Changes. Nose/Cheek Flattening appears to show the highest correlation with the presence of pain in the rat.
GS for rats has been used to assess pain due to surgery, orthodontic tooth movement, osteoarthritis, acute chemotherapy-induced mucositis, and the efficacy of analgesics for these procedures and other painful conditions. Furthermore, GS have been used to examine the effects of postoperative analgesia on the reduction of post-operative cognitive dysfunction in aged rats.
As with mice, studies have examined the extent of agreement in assessing pain between rat GS and the use of von Frey filaments. Good agreement has been found between these in relation to three models of pain (intraplantar carrageenan, intraplantar complete Freund's adjuvant and plantar incision). The GS score significantly increased in all pain models and the peak GS score also coincided with the development of paw hypersensitivity, although hypersensitivity persisted after GS scores returned to baseline.
For rats, software (Rodent Face Finder) has been developed which successfully automates the most labour-intensive step in the process of quantifying the GS, i.e. frame-grabbing individual face-containing frames from digital video, which is hindered by animals not looking directly at the camera or poor images due to motion blurring.
In rabbits
A GS for rabbits using four FAU, i.e. Orbital Tightening, Cheek Flattening, Nose Shape, Whisker Position (Ear Position is excluded from the analysis) has been developed (for exemplar images, see here ) and used to assess the effectiveness of an analgesic cream for rabbits having undergone ear-tattooing. Similarly, a GS has been used to evaluate wellness in the post-procedural monitoring of rabbits.
In horses
Based on the identification of FAU in rodents and rabbits, a GS for horses has been developed from post-operative (castration) individuals. This is based on six FAU, i.e. Stiffly Backwards Ears, Orbital Tightening, Tension Above the Eye Area, Prominent Strained Chewing Muscles, Mouth Strained and Pronounced Chin, Strained Nostrils and Flattening of the Profile (for exemplar images, see here.) The HGS has thereafter been used to evaluate pain behavior in the laminitic horse, where it was concluded that the grimace scale can be used to assess the degree of pain also here, when compared to the Obel scale.
A related study describes the equine "pain face" after pain induction by a tourniquet on the antebrachium or topical capsaicin. The pain face here involves similar facial expressions described for the HGS; low and/or asymmetrical ears, an angled appearance of the eyes, a withdrawn and/or tense stare, medio-laterally dilated nostrils and tension of the lips, chin and certain mimetic muscles and can potentially be incorporated to improve existing pain evaluation tools. From the described pain face, The Equine Pain Scale has been developed.
Another pain scale has been described (EQUUS-FAP) which also has proven to assess acute pain in horses in a significant way.
To map and explain the different facial expressions seen in the equine face during acute pain, an equine facial action coding system (EquiFACS) has been developed. Seventeen FAU have been identified and the involved anatomical structures behind each facial expression are explained and compared to facial expressions seen in other species.
In cats
A preliminary study based on landmarks and distances between ears and in the muzzle demonstrated that observers shown facial images from painful and pain-free cats had difficulty in identifying pain-free from painful cats, with only 13% of observers being able to discriminate more than 80% of painful cats. Accuracy (based on a dichotomous judgement - pain or no pain) ranged from 18 to 94%.
A complete GS (Feline Grimace Scale - FGS) for cats was published in 2019 to detect naturally-occurring acute pain. Five FAU were identified: ear position, orbital tightening, muzzle tension, whiskers change and head position. Each FAU receives a score from 0 to 2 and a total pain score is calculated as the sum of the FAU's scores divided by the total possible score excluding those AU marked as "not possible to score" (i.e. 4/10 = 0.4 or 4/8 = 0.5). A training manual is available as "Supplementary information" within the original article.
The FGS has been thoroughly validated and reported high discriminative ability, good overall inter-rater reliability, excellent intra-rater reliability, and excellent internal consistency. The FGS scores were higher in painful than in control cats; a very strong correlation with another validated instrument for pain assessment in cats was observed and the FGS detected response to analgesic treatment (scores after analgesia were lower than before). Additionally, an analgesic threshold was determined (total pain score >0.39 out of 1.0). The FGS is an easy and quick-to-use tool for acute pain assessment in cats.
The clinical applicability of the FGS in cats undergoing ovariohysterectomy has been explored by comparing the scores assigned in real-time by an experienced observer with those scores assigned to still images, and good agreement has been reported. The FGS is also a reliable tool for pain assessment in cats undergoing dental extractions and the caregiver's presence did not affect FGS scores.
In sheep
A GS for sheep has been developed to detect pain caused by naturally occurring diseases such as footrot and mastitis. A GS has been used to assess pain due to the routine husbandry procedure of tail-docking in lambs. There was high reliability between and within the observers, and high accuracy. Restraint of the lambs during the tail-docking caused changes in facial expression, which needs to be taken into account in use of the GS.
In ferrets
Facial musculature of ferrets and compared lateral photographs of ferret faces were studied before and after intraperitoneal telemetry probe implantation. The FAU orbital tightening, nose bulging, cheek bulging, ear changes and whisker retraction were identified as potential indicators of pain in ferrets. All AU-scores assigned to the photographs taken five hours after surgery were significantly higher compared to their time-matched baseline scores. Further analysis using weights that were obtained using a Linear Discriminant Analysis revealed that scoring orbital tightening alone was sufficient to make this distinction with high sensitivity, specificity and accuracy.
See also
Three Rs (animal research)
References
Animal testing
Animal welfare
Nociception
Pain
Pain in animals
Pain scales
Suffering | Grimace scale | [
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49,083,688 | https://en.wikipedia.org/wiki/Romanesque%20Revival%20architecture%20in%20the%20United%20Kingdom | Romanesque Revival, Norman Revival or Neo-Norman styles of building in the United Kingdom were inspired by the Romanesque architecture of the 11th and 12th centuries AD.
In the United Kingdom it started to appear as an architectural style in the 18th. century but reached its greatest popularity in the mid to latter years of the 19th. century. The style can be viewed as a strand of Gothic Revival architecture and part of the Historicist or Historismus styles of architecture that became popular in both Europe and Britain during the 19th. century. Early examples of the style in Germany of the 1820s and 1830s are referred to as Rundbogenstil or round arched style. In Britain the style was introduced by architects and their patrons, who had been on tours in Europe and it appears that the German and British styles of Romanesque developed largely independently. Initially in Britain the style was used for church building, but as the 19th. century progressed it was adapted for public buildings, museums, schools and commercial buildings, but rarely for domestic buildings. By the start of the 20th. century it had gone out of fashion and only occasionally were examples of the style built.
Origins
The development of the Norman revival style or Neo-Norman took place over a long time in the British Isles starting with Inigo Jones‘s re-fenestration of the White Tower of the Tower of London in 1637–38 and work at Windsor Castle by Hugh May for Charles II, but this was little more than restoration work. More surprising is the west door of Kenilworth Church, inserted in the tower in 1570 probably at the time of a visit of Queen Elizabeth. This appears to have been historic arch, sourced possibly from an unknown monastic building, Another early example of Romanesque revival is the south porch of North Scarle Church in Lincolnshire. Pevsner suggests that it might be Elizabethan, but late 17th. century seems more likely as the oak door seems to be original and probably of that date.
In the 18th century the use of round arched windows was thought of as being Saxon rather than Norman and examples of buildings with round arched windows include Shirburn Castle in Oxfordshire, Wentworth in Yorkshire and Enmore Castle in Somerset. At Allerton Mauleverer in Yorkshire St Martin’s Church was re-built for Richard Arundell in 1745. The church has been described as a proto-Neo-Norman. While it gives the impression of a Romanesque revival church, with a massive crossing tower and round headed windows, yet it also has windows with gothic tracery and a hammerbeam nave roof. The architect is thought to have been John Vardy surveyor to the Office of Works.
A further example of church building in the Romanesque revival style took place in 1792 when Elisa Wingfield commissioned plans from Samuel Pepys Cockerell for the conservation and rebuilding of St Peter's Church, Tickencote in Rutland. The church which contained much notable Romanesque decoration and an elaborate chancel arch appears to have been close to collapse. Cockerell encased the chancel, keeping the arch in position but the outer walls were completely re-built and the exterior ornamentation of arcades and round headed windows were replaced in new stonework. A new tower over a porch was built on the south side, which gave added stability to the older structure. The nave was completely re-built using some new romanesque mot is and copying others, such as the engaged columns, from those on the exterior of the chancel. This style of Romanesque revival architecture is very similar to the style that emerges in the 1840s under architectects such as Thomas Penson and Benjamin Ferrey. Tickencote could be considered to mark the start of the Romanesque revival in church architecture.
In Scotland the style started to emerge with the Duke of Argyll’s castle at Inverary, started in 1744, and castles by Robert Adam at Culzean (1771), Oxenfoord (1780–2), Dalquharran (1782–5), and Seton Palace (1792). In England James Wyatt used round arched windows at Sandleford Priory, Berkshire in 1780–79 and the Duke of Norfolk started to rebuild Arundel Castle, while Eastnor Castle in Herefordshire was built by Robert Smirke between 1812 and 1820.
At Eastnor Smirke combines a rugged Romanesque with more subtle Gothic window tracery.
The elements of Eastnor are further developed about 1840 at Devizes Castle, where the Bath architect Henry Goodridge combines the Castellated gothic style of Eastnor with a Romanesque entrance arch and Romanesque windows.
Development of archaeologically correct Romanesque
It was at this point that the Norman Revival became a recognisable architectural style. In 1817 Thomas Rickman published his An Attempt to Discriminate the Styles of English Architecture from the Conquest to the Reformation. It was now realised that round-arch architecture was largely Romanesque in the British Isles and came to be described as Norman rather than Saxon. This distinction was finally recognised when Rickman’s article in Archaeologia (1832–33), was published by the Society of Antiquaries. The start of an archaeologically correct Norman Revival can be recognised in the architecture of Thomas Hopper. His first attempt at this style was at Gosford Castle in Armagh in Ireland, but far more successful was his Penrhyn Castle near Bangor in North Wales. This was built for the Pennant family, between 1820 and 1837.
An example of Romanesque revival architecture being used for follies in 1832 was by George Proctor at Benington Lordship in Hertfordshire. Proctor added a neo-Norman gatehouse, summerhouse and curtain wall to the site of a Motte-and-bailey castle. The arches and decorative features to the gatehouse and summerhouse were in Pulhamite, a form of Cast stone that was manufactured by James Pulham and Son.
The Neo-Norman style did not catch on for domestic buildings, though many country houses and mock castles were built in the Castle Gothic or Castellated style during the Victorian period, which were mixed Gothic styles.
Church architecture and the Romanesque Revival
However, the Norman Revival did catch on for church architecture. It was Thomas Penson, a Welsh architect, who would have been familiar with Hopper’s work at Penrhyn, who developed Romanesque Revival church architecture. Penson was influenced by French and Belgian Romanesque architecture, and particularly the earlier Romanesque phase of German Brick Gothic. At St David’s Newtown, 1843–47 and St Agatha’s Llanymynech, 1845, he copies the tower of St. Salvator's Cathedral, Bruges. Other examples of Romanesque revival by Penson are Christ Church, Welshpool, 1839–1844, and the porch to Langedwyn Church. He was an innovator in the use of terracotta to produce decorative Romanesque mouldings, saving on the expense of stonework. Penson’s last church in the Romanesque Revival style was Rhosllannerchrugog, Wrexham of 1852
Sara Losh and Wreay Church
A most remarkable example of Romanesque church building was St Mary’s Church at Wreay, near Carlisle. This was designed by Sara Losh and built between 1841 and 1842. Losh had travelled widely on the Continent and particularly in Italy and drew inspiration from Romanesque sources. Losh is known to have read Thomas Hope's Historical Study of Architecture (1815), which uses the term Lombardic for the style brought into Italy from the early Christian churches of Constantinople, and she described St Mary's as being an unpolished mode of building that most approximates to early Saxon or modified Lombard This statement suggests that at the time of its design Losh was not aware of Thomas Rickman’s re-classification of Saxon and Norman architecture. While the appearance and layout of the church may be considered as Romanesque, her free interpretation of the decoration on the woodwork and the arched stone windows and doors is anticipating the styles of the Arts and Crafts movement, while the arcading of the apse certainly has a Byzantine feel to it.
Sarah Losh gallery
Other Early Victorian architects working in the Romanesque revival style
The early years of the 1840s saw a considerable upsurge of interest in the developing Romanesque revival style by some of the leading architects of the period. During the 19th century the architecture selected for Anglican churches depended on the churchmanship of particular congregations. Whereas high churches and Anglo-Catholic, which were influenced by the Oxford Movement, were built in Gothic Revival architecture; low churches and Broad churches of the period were often built in the Romanesque Revival style. The architects specialising in Romanesque revival took their designs from different local styles of the European Romanesque.
Edmund Sharpe
Another architect who popularised the Romanesque revival style was Edmund Sharpe, who set up his practice at Lancaster in 1835. At Cambridge he had been a great friend of William Whewell and presumably of the polymath and architectural historian Professor Robert Willis. He was awarded a travelling scholarship to study the early architecture of Germany and Southern France and supplied Thomas Rickman with information. However, Sharpe despite being an architectural historian of some note, built churches that were much freer interpretations of the Romanesque and German Brick Gothic and might be considered less archaeologically correct.
Four of Sharpe's earliest churches – St Saviour, Bamber Bridge (1836–37); St Mark, Witton (1836–38); and St Paul, Farington, near Leyland (1839–40) – were in the Romanesque style, which he chose because no style can be worked so cheap as the Romanesque. They turned out to be little more than rectangular 'preaching boxes'… with no frills and little ornamentation; and many of them were later enlarged. The only subsequent churches in which Sharpe used Romanesque elements St Mary's Church, Conistone in Wharfedale (1846); and St Paul, Scotforth in south Lancaster (1874–6). Sharpe's final essay in the Romanesque Revival style St Paul's Church, Scotforth, was described by Nikolaus Pevsner as a strange building and an anachronism, almost beyond belief. Sharpe had retired from his architectural practice in 1851. He then pursued a career in railway engineering. In 1874, when he was aged 68, he returned to architecture and designed this church which was opened in 1876. The church had used terracotta in a similar fashion to his earliest churches and it can only be assumed that its anachronistic appearance was that he had used a design that he had prepared at least 20 years earlier.
Romanesque by Sharpe
Benjamin Ferrey
The work of Benjamin Ferrey can be considered to be similar to that of Thomas Penson, based on the English and French Romanesque traditions. An early example is his church of St Nicholas at East Grafton in Wiltshire, built in 1842–44. Here the chancel terminates in an apse and the west has overlapping arcading and chevron decoration over the entrance door. Central crossing tower and arcaded windows on the west frontis approached through a stone Romanesque Lych gate.
A more important work by Ferrey is the Church of St James the Great at Morpeth, Northumberland. The church, which is supposed to be modelled on the Cathedral of Monreale in Sicily, was built between 1844 and 1846. The unusual arched gate is acceptably Sicilian in inspiration and is similar to the portico at the cathedral at Monreale, but the rest of the composition has much more in common with French and Belgian Romanesque. A further church in this style is Christ Church in Melplash in Dorset of 1845–46. This has a heavy crossing tower and in many respects resembles the Church of St. James the Great at Morpeth.
Romanesque by Ferrey
William Perkin of Leeds
St Michael and All Angels Barton le Street, North Yorkshire.
This church was very extensively rebuilt in 1869–71 by William Perkin and his sons of Leeds. Unlike Tickencote there is no record of the church that was replaced. The building contains an extensive and impressive range of genuine romanesque, but these seem to have been largely repositioned. The pews and some other furnishings are in Romanesque revival style. The rebuilding was financed by Hugo Francis Meynell-Ingram.
Barton le Street Gallery
Romanesque gallery
Chapel architecture
In the 1860s, Romanesque architecture became a popular style of architecture for Dissenting chapels. Possibly this was intended to give the impression that they were churches similar to Anglican churches and they are often referred to as churches rather than chapels. This form of architecture was often chosen by the Baptists. This architecture is an adapted and debased form of Italianate Romanesque as seen at the Potter's Bar Old Baptist Church in Hertfordshire in 1859. The Baptist Church in Brown Street Salisbury of the 1880s is similar in bright red brick and was built in the 1880s. It is noticeably more archaeologically correct in its use of arched windows and the entrance door. A Baptist Chapel of 1870 by the Lincoln architects Drury and Mortimer, the Mint Lane Baptist Chapel in Lincoln is in a debased Italianate Romanesque revival style but has a surprising tower in the castellated Gothic style.
Synagogues
The Romanesque revival was also a style of architecture that appealed to Jewish communities and there are examples of Synagogues in this style.
One of these is the synagogue built adjacent to the docks at Grimsby in Lincolnshire.
Later Romanesque Revival churches in Scotland
The earliest example of Romanesque revival architecture in Scotland is the West Kirk, Sandgate, Ayr. By the architect William Gale for the Presbyterian Free Church and built in 1844–45. The columns used for the windows are very similar to those used by Edmund Sharpe at Scotford church.
In Scotland the Presbyterians occasionally built in the Romanesque revival style, but only later in the 19th century.
St Conan’s Kirk Lochawe, Agyll and Bute is an extraordinary early 20th century church on the shore of Loch Awe, built by Walter Douglas Campbell, brother of the 1st Lord Blythswood, was started in 1881, but not completed until 1930. The kirk is largely Romanesque in style, but is also mixed with other completely unrelated styles. Another church is Cranshaws in Berwickshire. Here the 1739 church was rebuilt in 1899 by architect George Fortune in Romanesque Revival style.
Sir Alfred Waterhouse and developed Romanesque Architecture
Interest in Romanesque Revival Architecture was renewed by Sir Alfred Waterhouse's Natural History Museum in Kensington, which was built between 1873 and 1881. It was built in shades of buff coloured terracotta and opened the way for the Romanesque style to be used for other buildings, apart from churches. Waterhouse tended to mix the architectural styles, often using decorative Romanesque arches to provide impressive entrances for his buildings, and popularised the deep red terracotta produced by manufacturer's in the Wrexham and Ruabon area of North-East Wales. This included parts of the Prudential Insurance building in London and the entrance to Strangeways Prison.
Buildings by Waterhouse
Later 19th and 20th century
Waterhouse inspired other architects to build using terracotta and this material was used by William Watkins, a Lincoln architect who very successfully used a deep red Ruabon terracotta for the Lincoln Christ's Hospital Girls School of 1893. An earlier building by Watkins of 1873, was originally built as a warehouse at 42 Silver Street, Lincoln. This uses artificial stone for Romanesque columns and arches to embellish the frontage.
St Aidan's Church, Leeds
St Aidan's Church, Leeds is a massive basilica church built in the tradition of Waterhouse, using red terracotta brickwork. The design was won by competition in 1889 and the church was built between 1891 and 1894 by the Newcastle architects RJ Johnson and A Crawford Hick. The style is a hybrid of Italian, French and German Romanesque and the Corbel table or moulded stringcourse below the eaves was based on that of Lund Cathedral in Sweden. The inside is sumptuously decorated with mosaic decoration by Sir Frank Brangwyn in the apse and a multi-coloured marble font with Romanesque arcading. The interior columns of the basilica have ornamental capitals in the Byzantine style.
20th century
In the 20th.century the use of the Romanesque revival style in church architecture appears to be restricted to brick built churches and often these churches have similarities with churches built in the Byzantine revival style, which became more popular in the early years of the 20th century.
Churches in the Romanesque revival style include All Saints, Bute Avenue, Petersham, Richmond-upon-Thames. This Romanesque revival church was designed by J Kelly and completed in 1908.
An even later example of the style is St Francis, Linden Road, Bournville, consecrated in 1925. This church was designed by Harvey and Wicks, the architects of the Bournville Estate
References
Sources and further reading
External links
Architectural history
British architectural styles
Revival architectural styles
Victorian architectural styles | Romanesque Revival architecture in the United Kingdom | [
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"Architectural history",
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49,083,839 | https://en.wikipedia.org/wiki/Social%20employee | A social employee is a worker operating within a social business model. Following an organization's social computing guidelines, social employees use social media tools both for internal workflow and collaboration purposes and for external engagement with customers, prospects and stakeholders through a combination of social media marketing, content marketing, social marketing, and social selling. Social employee programs are considered to be as much about culture and engagement as they are about business processes and best practices. In addition to increased leads and sales, social employee best practices are said to improve business outcomes important to social media marketing, such as increased connections and web traffic, improved brand identification and "chatter", and better customer advocacy.
Overview
The term "social employee" was first introduced to describe those exhibiting the emerging characteristics of workers operating under a social business model.
The term is often used interchangeably with similar designations like "employee advocate" or "social employee advocate".
Crucial to the perceived value of the social employee is the concept of the digital footprint. While organizations are able to generate large bases of followers through social media, research shows that brand marketing and engagement efforts through these networks are not as effective as those of individual employees. In fact, some research indicates that employee experts are more trusted than any other member of an organization. Because of this, social employee programs are designed to train, empower, and support employee engagement efforts in the hopes of authentically engaging larger communities, increasing the frequency of shares, reviews, and other forms of "earned media" and expanding the brand's presence on the web.
The personal or employee brand
A foundational concept of the social employee is the idea of the personal or employee brand. This concept first gained popular attention in a 1997 FastCompany article by business leader Tom Peters titled "The Brand Called You". In the article, Peters argued that the premium placed on branding impacted workers' lives to such an extent that creating and cultivating a distinct personal brand had become a professional necessity. According to Peters, doing so built trust, loyalty, visibility, influence, and employability.
With increased adoption of social media tools by both businesses and consumers in the early 21st century, many business leaders became increasingly concerned with social engagement, both internally among employees and externally with customers and other stakeholders. While many in the business community acknowledged the potential social tools had for improved collaboration, productivity, and brand messaging, the concern that employees would misrepresent their brand, disclose proprietary information, or otherwise damage their company's reputation or ability to conduct business persisted.
As a result, many began to advocate for employee branding as a solution to this problem. This helped give new meaning to the concept of brand ambassadorship, positioning everyday employees in public, and potentially high-profile, engagement roles.
Characteristics
Engaged
Because social employee advocacy is dependent on the perceived authenticity of the employee, engagement is highly valued in social organizations. Further, data show the measurable impact of employee engagement on organizational productivity and profitability:
Happy employees were found to be 12 percent more productive.
In one study, engaged employees were found to be 38 percent more likely to produce at above-average rates. In another, organizations with engaged employees had a 19 percent higher than average shareholder return, while organizations with disengaged employees experienced shareholder return that was 44 percent below average.
Engaged companies were found to outperform disengaged companies by up to 202 percent.
Companies with strong focus on culture were found to have an average 13.9 percent turnover rate, while those with a low focus experience were found to have a 48.4 percent turnover rate.
Flexible job environment and work–life balance
The number of professionals working mobile or remote has risen considerably since 2010. While estimates vary, one study found that number of organizations with mobile or remote employees is expected to rise from 24 percent in 2012 to 89 percent by 2020. Other research has estimated that by 2020, 105.4 million professionals will work remotely in America, about 72.3 percent of the total workforce.
This change has been linked to a rise in social technologies, including biometrics, wearables, near-field communications, and augmented reality. Social employees have also put a greater emphasis on work–life balance, with many believing that advances in technology can directly support efforts in this area. Purported benefits of this shift include a more flexible workforce, reduced business costs, and greater organizational leverage in attracting and retaining top talent.
Buys into the brand's story
In 2009, thought leader Simon Sinek presented a speech called "How Great Leaders Inspire Action" at a TEDxPugetSound event. Sinek's central argument in this speech was, "People don't buy what you do. They buy why you do it." This concept—that the story behind a business or product offering is a more compelling sales tool than the product itself—is frequently cited in social media marketing as a way to build authentic connections with stakeholders. However, others have argued that for employees to share a brand's story authentically, they must be engaged in that story themselves, and as a result, many companies have made storytelling part of their culture programs.
Collaborative
An implicit tenet in social business is that social technologies aren't a barrier to productivity, but rather a path to increased connectivity. The shift in enterprise software systems like IBM Connections to incorporate social communication models, such as mentions, wikis, and newsfeeds, reflects the changing communication dynamics within business. With an increase in diversity and sophistication in collaborative software platforms, social organizations have sought to find new creative ways to utilize these tools and secure employee buy-in around them.
Crowdsourcing has also become popular in social businesses. Examples include AT&T's program The Innovation Pipeline (TIP), begun in 2009, which has generated over 28,000 ideas that have led to over 75 projects with funding exceeding $44 million. IBM has also put considerable resources into such processes, producing its social computing guidelines through employee crowdsourcing, as well as its Connections platform through the Technology Adoption Program (TAP), a more formalized crowdsourcing initiative.
Another popular form of internal collaboration is the hack day, or hackathon. Organizations such as Netflix, Facebook, and IBM use hack days to pull employees out of their day-to-day work environments and encourage them to collaborate in nontraditional ways in an attempt to drive disruptive innovation.
Social employees are often encouraged to seek external collaboration opportunities with customers and prospects. For example, Procter & Gamble introduced the Live Well Collaborative to connect with external stakeholders and develop products and services for the 50+ demographic.
Social listener
A social listener is someone who engages in social listening, or social media monitoring, for professional means. Social employees can use social media monitoring for a variety of reasons, including professional development, industry news and trends, and gauging market sentiment. Some have argued that social listening is one of the most important components of social business, as it enables organizations to collect rich market data, make more informed strategic decisions, and respond to customer needs more authentically.
Customer-centric
Advocates of customer-centricity in social business argue that social media has changed the dynamic from one-way brand messaging to shared interactions between brand and customer. Brand and customer engagement is seen as a means of creating more lasting connections with customers and prospects and empowering them to become brand promoters. Customer-centric interactions are seen to have distinct value to brands, as research shows that prospects are far more likely to trust brand-related messaging from a friend or family member than they are from a brand.
As a means of building social employees, some social advocates have also called for a broader definition of customer to include the employees themselves. In the book The Pursuit of Social Business Excellence, authors Vala Afshar and Brad Martin made the following argument: A social business operates with the guiding principle that each employee's responsibility is to serve one another, and that those we serve, even internally, are our customers. To earn internal customer trust and loyalty, each employee must be dependable, available, responsive, and committed to the success of the whole.
Adaptable
The relatively quick proliferation and prioritization of social media in business has driven a need for organizations to be more flexible and responsive. This in turn has led to a reprioritization of employee skill sets in which adaptability, self-directed learning, and organizational sharing are highly valued.
Common features of social employee programs
According to Weber Shandwick, 47 percent of employees are either already prepared to advocate for their employers or willing to learn. Of those, 21 percent are what the study refers to as "ProActivists," or early adopters, employees who actively use social media for professional purposes, with about half of this group already posting about their employer through social channels.
Pilot program
Many organizations begin with a social employee pilot program to determine best practices suitable to their organizational structure. Program design depends in part on the size of the organization and the desired scope of social adoption. For instance, whereas Domo implemented a mandatory pilot program requiring the participation of all its staff, Dell recruited approximately 200 employee participants through what was called the Social Media and Communities (SMaC) University.
Discovery
A common first step in a social employee pilot program is an initial process of discovery in which organizations attempt to identify and quantify their current resources. This can include a roll call of employee early adopters, an internal audit of informal adoption of social tools and practices, or a skills test to determine current adoption rates.
Social computing policy
Many organizations will recruit employees to actively participate in designing the pilot program. A fundamental concern of social media use in business has been its potential for abuse—specifically regarding the release of confidential information, negative or off-brand messages, and security risks. Because of this, one focus in many social employee pilot programs has been to establish a set of social media guidelines. For example, IBM created an internal wiki and invited employees to help build a document laying out acceptable social engagement guidelines.
Training
To social organizations, social employee training helps to unify employee programs and tools throughout the organization and establishes a common knowledge base and set of best practices to assist employees in sharing and decision-making. Many organizations us a combination of in-person training, digital learning modules, and social learning principles.
Social employee training often applies the 70/20/10 learning model as its basis. In this model, 70 percent of learning is self-directed, 20 percent is informal mentoring or coaching, and 10 percent is formal training. Applying this dynamic, many organizations work to design a "digital learning experience" in which employees can access learning modules and other subject-specific content to help them acquire new skills.
Training is often divided into mandatory basic skills modules and optional advanced skills modules. To determine what social knowledge an employee needs, a baseline or "social IQ" test is often administered. Many organizations, such as Adobe with its Center of Excellence (CoE) and Dell with its SMaC University, have expanded their training programs to establish a more permanent resource for employees.
Because social employee best practices affect organizational practice and culture in a broad way, upper management and executives are also encouraged to adopt social engagement best practices. Doing so is said to help drive buy-in among the workforce and reinforce organizational commitment to the program. Training for upper management and executives can often involve a process known as "reverse mentoring," in which a lower-level employee is brought in to help develop a senior-level manager's skills and basic digital literacy.
Social engagement and content marketing
Social engagement and sharing through both internal and external channels are considered key components of social employee design. Employees are encouraged to communicate with coworkers, customers, prospects, and stakeholders through social channels by sharing industry-related news or user-generated content.
Internally, this process is often centered on keeping employees updated on company and industry news, helping employees collaborate on projects, and building culture. Many enterprise-level social platforms have been developed to facilitate such objectives, including task management platforms, wikis, file-sharing tools, and messaging services.
Externally, the focus is often on customer engagement, often through content marketing practices. Research has shown that social sharing can have a positive impact on metrics such as brand engagement, web traffic, and sales. The advent of digital commerce has led customers to research products more thoroughly before make a purchase decision, using social reviews, peer recommendations, and product-specific content to help guide their decisions. Because of the value of peer recommendations specifically, a primary of goal of content marketing is to encourage customers and prospects to share the content among their personal networks as a form of "earned" advocacy.
Another popular social engagement strategy with stakeholders is resharing advocate-generated content through branded channels. This is believed to strengthen relationships with stakeholders and help to humanize the brand.
Assessment
Measuring the success social employee advocacy programs has presented a challenge to many organizations. While a small percentage of organizations assert that they are able to measure and validate their investment in social marketing, a larger percentage is either only qualitatively aware of the success of their social efforts or unable to measure whatsoever.
Social business thought leaders argue that assessing the success of social employee programs must take into account more than financial return on investment (ROI). Companies that consider a broader set of metrics than financial return often measure success through a variety of key performance indicators:
Number of employee profile views and connections
Number of leads from social channels
Rate at which employee network grows
Frequency of shares and interactions
Increase in online "chatter" about a brand
Ability to attract and retain skilled talent
Increases in visibility, inbound web traffic, brand recognition, and brand loyalty
Many organizations, however, do report financial benefits as well. Social employees are more likely to exceed their sales quota, and social businesses in general are more likely to see increased sales leads and increase in revenues.
Gamification, engagement, and culture-building programs
Culture-building programs vary in scope and complexity, but all use social media in some way to underscore employee, departmental, or organizational accomplishments. Program leaders will issue social engagement challenges to help employees meet goals. Challenges can include number of connections (i.e., likes or follows, retweets), number of leads, or frequency of posts (i.e., status updates, tweets, blogs, etc.). For a more competitive element, some organizations will employ gamification strategies such as leaderboards, achievement badges, and scavenger hunts.
See also
Content marketing
Engagement marketing
Enterprise social software
Integrated marketing communications
Organizational culture
Reputation management
Social business model
Social marketing
Social media
Social media optimization
Social selling
References
Social media | Social employee | [
"Technology"
] | 2,970 | [
"Computing and society",
"Social media"
] |
49,084,264 | https://en.wikipedia.org/wiki/Air%20Force%20Institute%20of%20Technology%20%28Nigeria%29 | The Air Force Institute of Technology (AFIT) also known as the Nigeria Air Force University is a military school approved by the National Universities Commission to run undergraduate and postgraduate courses in 2018/2019. It supports the Nigerian Air Force (NAF) and civilian communities by provision of basic training on Aeronautics, aerospace engineering mechatronics engineering and avionics. It is located in Kaduna state, Northern side of Nigeria.
Overview
Following the outbreak of the Nigerian civil war, variety of aircraft types and associated weapon systems resulted in a skilled manpower to operate and maintain them. The NAF at that time depended on foreign assistance for manpower development. However, the training vacancies which friendly overseas countries offered the NAF were limited, inadequate and also required huge foreign exchange financing. Consequently, soon after the civil war in 1970, HQ NAF mooted the idea of establishing an indigenous Technical and Supply School.
AFIT was founded in 1977 with the name NAF Technical and Supply School (TSS). It was supported by Messrs Dornier of Germany. The institute was renamed in 1979 as Technical Training Wing and was called NAF Technical Training Group (NAF TTG). The group was tasked with the responsibility of providing basic training for NAF personnel in the field of aircraft maintenance, armament and communication. Others are supply management. By the year 2000, its identity was changed to 320 Technical Training Group (320TTG). It was created to manage aircraft and equipment bought during Nigerian Civil War in 1967.
The need to keep pace with technological development through increase in manpower capacity building further led to upgrade of most of the certificates awarded by the institution to a National Diploma, with full accreditation by the National Board for Technical Education, (NBTE). The institute was also affiliated with Cranfield university, UK for post Graduate Studies in Aerospace Vehicle Design and related fields and it became evident and necessary to effect a change in the nomenclature to reflect the expanded role of the institute. AFIT thus came into being on 12 March 2008.
Faculties
Currently, AFIT comprises 5 faculties, each consisting of various departments. The faculties are: Air Engineering, Computing, Ground and Communication Engineering, Social and Management Sciences and Faculty of Sciences. There is also a School of Postgraduate Studies (SPS). All the basic course curricula are structured to meet the minimum requirements for MSc in the aerospace sector.
The institute has so far graduated over 5,689 persons, including personnel of the Nigerian Army, Nigerian Navy and NAF as well as civilians. It is pertinent to state that this number includes foreign students from the Armed Forces of the Republic of Benin, Zimbabwe, Niger, Ghana and Sierra Leone.
AFIT Transformation
The Chief of the Air Staff, Air Marshal SB Abubakar through whose vision to "reposition the NAF into a highly professional and disciplined force through capacity building initiatives for effective, efficient and timely employment of air power in response to Nigeria's national security imperatives" has helped AFIT to get the NUC accreditation. AFIT has recently recorded a milestone, as it obtained the status of a university. The school was given approval to begin degree programmes on 3 August 2018. Following this new achievement the school will begin its degree programme by September 2018.
Structure
The following courses are approved under the various faculties and departments:
Master's programmes
M.Sc. Aerospace Vehicle Design
M.Sc. Thermal Power
Postgraduate diploma
PGD Aerospace Engineering
PGD Electrical and Electronics Engineering
PGD Construction Technology
PGD Logistics and supply chain Management
First degree programmes
B.Eng. Aerospace Engineering
B.Eng. Mechanical Engineering
B.Eng. Electrical and Electronics Engineering
B.Eng. Information & Communication Technology
B.Eng. Automotive Engineering
B.Eng. Civil Engineering
B.Sc. Accounting
B.Sc. Business Administration
B.Sc. Economics
B.Sc. Marketing
B.Sc. Cyber Security
Recent courses
B.Eng mechatronics engineering
B.Eng metallurgical and material engineering
B.Eng telecommunication engineering
B.Sc. computer science
B.Sc. chemistry
B.Sc. mathematics
B.Sc. physics
B.Sc. physics with electronics
B.Sc. marketing
B.Sc. statistics
B.Sc. international relation
B.Sc. banking and finance
References
External links
Official Website
1977 establishments in Nigeria
Educational institutions established in 1977
Engineering universities and colleges | Air Force Institute of Technology (Nigeria) | [
"Engineering"
] | 878 | [
"Engineering universities and colleges"
] |
49,084,345 | https://en.wikipedia.org/wiki/Drawdown%20%28climate%29 | Climate drawdown refers to the future point in time when levels of greenhouse gas concentrations in the atmosphere stop climbing and start to steadily decline. Drawdown is a milestone in reversing climate change and eventually reducing global average temperatures. Project Drawdown refers to a nonprofit organization which tries to help the world reach drawdown and stop climate change. In 2017, a publication titled "Drawdown" highlighted and described different solutions and efforts available to help reach this goal.
Project Drawdown
Project Drawdown is a climate change mitigation project initiated by Paul Hawken and climate activist Amanda Joy Ravenhill.
The Project Drawdown website includes video lessons that explain the analysis and insights behind the efforts and research that make up the science behind the project. Central to the project is the compilation of a list of the "most substantive solutions to global warming". The list, which encompasses only technologically viable existing solutions, was compiled by a team of more than 200 scholars, scientists, policymakers, business leaders, and activists and is now online. The team measured and modeled each solution's carbon impact through the year 2050, its total and net cost to society, and its total lifetime savings. Project Drawdown uses different scenarios to assess what different changes to global climate efforts might look like. Scenario 1 shows a 2°C temperature rise by the year 2100, while Scenario 2 shows a 1.5°C temperature increase within the same temporal range. Below is a table of the top ten solutions included on the organization's website, with the impacts of their respective emissions based on either. The measurements refer to the gigatons of carbon dioxide () equivalent reduced/sequestered (2020–2050) with the minimum efforts required for the higher goal, and the maximum efforts required for the lower goal.
Top ten solutions
Nine Sectors
The interactive website lists nine sectors where immediate action is needed to limit catastrophic climate change. They are:
Electricity: Electricity production gives rise to 25% of heat-trapping emissions globally. The solutions that apply to this sector include enhancing efficiency, shifting production (away from fossil fuels to nuclear power/solar energy/wind power/geothermal power), and improving/upgrading the system.
Food, Agriculture, and Land Use: Agriculture and forestry activities generate 24% of greenhouse gas emissions worldwide. Solutions in this sector are focused on waste and diets, ecosystem protection, and better agricultural practices. Farming and forestry can also support the role of natural sinks, which help remove greenhouse gases from the atmosphere.
Industry: The industry is directly responsible for 21% of all heat-trapping emissions. The solutions in this sector include improving materials (as plastic, metals, and cement are some of the most common materials that need production improvement), utilizing waste, addressing refrigerants, and enhancing efficiency. The industry presents some of the biggest challenges for reducing emissions.
Transportation: This sector is responsible for 14% of global greenhouse gas emissions. Solutions in this sector address transportation alternatives (public transit, compact cities, intentional infrastructure), energy efficiency enhancements, and the electrification of vehicles completely replacing fossil fuels. However substantial, these solutions have the potential to save money while avoiding pollution.
Buildings: Buildings produce 6% of heat-trapping emissions worldwide. They also use more than half of all electricity, which creates a large impact on electricity-generated emissions. The solutions for this sector encompass enhancing its efficiency, shifting energy sources, and addressing refrigerants.
Health and Education: Currently, the human population totals 7.7 billion, and the United Nations estimates that number will grow to between 9.4 billion and 10.1 billion in 2050. Population interacts with the primary drivers of emissions, production, and consumption. However, almost half of the consumption-related emissions are generated by just 10% of people globally, giving point to the critical note of disparities in emissions from high-income countries compared to lower ones and between the wealthiest individuals and those of lesser means. The solutions for this sector are also focused on family planning, reproductive health, and education.
Land Sinks: While the majority of heat-trapping emissions remain in the atmosphere, land sinks return 26% of human-caused emissions to Earth. This sector's solutions focus on protecting and restoring ecosystems, shifting agriculture practices, addressing waste and diets, and using degraded lands. (See also: Carbon sinks and land trusts)
Coastal and Ocean Sinks: Oceans have absorbed at least 90% of the excess heat generated by recent climate changes and have taken up 20–30% of human-created carbon dioxide. Coastal and ocean sinks bring 17% of all heat-trapping emissions back to Earth. However, the more carbon dioxide in seawater makes the ocean more acidic and less hospitable. This also leads to a rise in water temperatures, marine heat waves, and sea levels. Solutions for coastal and ocean sinks center on ecosystem protection and restoration and improved agricultural practices.
Engineered Sinks: The sheer quantity of excess greenhouse gases means that natural processes cannot do it all when it comes to carbon sequestration. Developing technologies show promise to help supplement previously mentioned natural sinks. Removing, capturing, and storing carbon are included in the central solution focus for this sector.
Book
Drawdown Review
A 2020 review of the findings of the research that led to the 2017 book was published as a 104-page PDF in 2020.
See also
Azolla event
Carbon sequestration
References
External links
Project Drawdown, headquartered in San Francisco, US
Drawdown Europe Research Association, headquartered in Amsterdam, the Netherlands
Greenhouse gas emissions
Climate change mitigation | Drawdown (climate) | [
"Chemistry"
] | 1,124 | [
"Greenhouse gases",
"Greenhouse gas emissions"
] |
49,085,532 | https://en.wikipedia.org/wiki/Circle%20of%20Poison | The Circle of Poison (COP) refers to the export of domestically banned pesticides for use on foods elsewhere, some of which returns by way of import. The "circle" is complete when the toxic chemicals that were exported are then used to grow fruit, meat, and produce that are imported and available for domestic consumption. This circle was first identified relative to the United States but the relationship also exists between other nations of the Global North and South.
History of concept
In the book, Circle of Poison: Pesticides and People in a Hungry World, David Weir and Mark Schapiro of the Oakland-based Center for Investigative Reporting present an investigative study of how certain dangerous chemicals, which are banned in the U.S., still enter back into the United States and the American diet through food imports. Many restricted chemicals, especially pesticides, are produced in the U.S. and exported to the global south. The banned chemicals are then used on 'cash crops', which are subsequently exported to the U.S. and other industrialized countries for high profit.
The investigative study done by Wier and Schapiro showed that the highly potent and dangerous chemicals used in domestic agriculture led to a public clamor for strict regulations, and that pesticides contribute to the expansion of an export-oriented agriculture at the expense of food production for local needs. Even where they are applied to food crops, pesticides are often linked to the Green Revolution, which can mean more hunger even while it raises production. Pesticides, they argue, are no solution to hunger-they bypass the needs of the poor who 'have neither money to buy food nor the land to grow it on'. Moreover, they claim because agrochemical companies are profit driven, they have tailored the regulations to permit unrestricted export of dangerous chemicals. Wier and Schapiro argue that this loophole has been a disaster.
Circle of Poison Prevention Act of 1991
In April 1991, the "Circle of Poison prevention Act" was introduced by Senator Patrick Leahy (D-VT) in the U.S. Senate and by Representatives Mike Synar (D-OK) and Leon Panetta (D-CA) in the House. This bill would have placed strict controls on exports of hazardous chemicals. Similar legislation passed both houses of Congress but died in conference committee.
In brief, the "Circle of Poison Prevention Act" would have:
Prohibited the export of pesticides that were not registered for domestic use; were not registered for food use and would not be exported for use on food; or had had the majority of registration canceled.
Permitted government to refuse the import of certain hazardous pesticides, including restricted-use pesticides and those which were conditionally registered or were the subject of cancellation proceedings.
Permitted citizens to file suit against violators to enforce the law.
Automatically revoked tolerances for pesticide residues on food for pesticides no longer registered in the U.S.
Required EPA to disseminate information on non-chemical pest control alternatives and sponsored meetings to develop improved strategies for sustainable agriculture, including integrated pest management and the use of non-chemical alternatives.
Pesticide regulations
The United States Environmental Protection Agency (EPA) has the authority to regulate the sale and use of pesticides in the United States; before a pesticide can be sold, it must be licensed or registered by the EPA. While registration does not constitute "approval" by the EPA, it means that the agency has determined that a pesticide will not cause 'unreasonable adverse effects' on humans or the environment. The EPA may cancel or suspend the registration of a pesticide, if further evidence indicates that its use poses unreasonable hazard. Or it may restrict the uses for which it may be sold to very specific crops and application practices.
The EPA does not have the authority to prohibit the export of canceled or suspended pesticides; nor may it forbid the export of restricted use pesticides that may be equally hazardous in the hands of untrained applicators or new compounds, which have never been granted registration. Consequently, millions of pounds of pesticides, which have been determined to be unsafe for use in the U.S., are shipped to foreign ports.
Federal pesticide laws
The Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA), and the Federal Food, Drug, and Cosmetic Act, are the two major laws responsible for pesticide control in the U.S. Department of Agriculture, and are also responsible for the safety of foods containing pesticide residues to the Department of Health, Education, and Welfare. The Secretary has delegated this responsibility to the Food and Drug Administration.
References
External links
Setting Tolerances for Pesticide Residues in Foods, www.epa.gov
Regulation of Pesticide Residues on Food, www.epa.gov
Circle of Poison. Al Jazeera English, November 2016 (documentary, video, 47 mins)
Pesticide regulation in the United States
Pesticides
Food safety
Food and the environment
Environmental impact of agriculture
Environmental health | Circle of Poison | [
"Biology",
"Environmental_science"
] | 1,011 | [
"Biocides",
"Toxicology",
"Pesticides"
] |
39,975,292 | https://en.wikipedia.org/wiki/Lyngurium | Lyngurium or Ligurium is the name of a mythical gemstone believed to be formed of the solidified urine of the lynx (the best ones coming from wild males). It was included in classical and "almost every medieval lapidary" or book of gems until it gradually disappeared from view in the 17th century.
Properties and history
As well as various medical properties, lyngurium was credited with the power to attract objects, including metal; in fact it seems likely that what was thought to be lyngurium was either a type of yellow amber, which was known to the Ancient Greeks, but obtained from the distant Baltic coast, or less likely forms of tourmaline. The first surviving description of Lyngurium is by Theophrastus (died c. 287 BC), and most later descriptions derive from his account. Theophrastus said it was:
...carved into signets and is hard as any stone, [and] has an unusual power. For it attracts other objects just as amber does, and some people claim that it acts not only on straws and leaves, but also on thin pieces of copper and iron, as Diocles maintained. The lyngurium is cold and very clear. A wild lynx produces better stones than a tame animal, and a male better ones than a female, there being a difference in the diet, in the exercise taken or not taken, and, in general, in the natural constitution of the body, in as much as the body is drier in the case of the former and more moist in the case of the latter. The stone is discovered only when experienced searchers dig it up, for when the lynx has passed its urine, it conceals it and scrapes soil over it.
In the 1st century AD Pliny the Elder discusses the stone, but makes it clear that he does not believe in it, or at least its supposed origin: "I for my part am of the opinion that the whole story is false and that no gemstone bearing this name has been seen in our time. Also false are the statements made simultaneously about its medical properties, to the effect that when it is taken in liquid it breaks up stones in the bladder, and that it relieves jaundice if it is swallowed in wine or even looked at". He also mentioned the belief that the hiding of the solidified urine was because lynxes had a "grudge against mankind", and deliberately hid what they knew to be highly beneficial objects for man. This idea was apparently also mentioned by Theophrastus in a different, lost, work On creatures said to be grudging, and was still alive in the 15th century: "she hidith it for envy that hire vertues shulde not helpe vs". Another version was that the lynx swallowed the stone and "withholt in his throte wel depe that the grete vertues there-of ne shulde nought be helpyng to vs" ("withholds it in his throat knowing that the virtues thereof should not be helping us").
The belief that male urine produced better stones related to a general ancient and medieval idea that inorganic materials could be gendered into generally superior male forms and their weaker female forms. The 11th century Islamic scientist Abū Rayḥān al-Bīrūnī was critical of a popular belief, not mentioned in other sources, that the stone could make people change gender.
The meaning and origin of the word seems to have been confused early on with a geographical origin, either in Liguria in northern Italy, or a part of Sicily which produced amber. A version of the name, apparently started by Flavius Josephus was ligure, and under this name the Vulgate Latin Bible described the seventh stone on the Priestly breastplate in the Book of Exodus, called either amber or jacinth in modern translations, though one 19th-century Danish translation used lyncuren.
Renaissance scepticism
Although "the first English zoology" The Noble Lyte and Nature of Man (1521) written or at least printed by Lawrence Andrewe, still said that the lynx's "pisse baketh in ye sonne and that becommeth a ryche stone", by 1607 the clergyman Edward Topsell, though repeating many fabulous medieval beliefs about zoology, rejected lyngurium: "Latines did feigne an etymology of the word Lyncurium and uppon this weake foundation have they raised that vaine buildinge". The death of belief in lyngurium generated a few attempts to find more scientific explanations, and a considerable amount of scholarly squabbling, but the absence of physical specimens was soon fatal.
See also
Hyraceum
Toadstone
Notes
References
Eichholz, D. E., "Some Mineralogical Problems in Theophrastus' De Lapidibus", The Classical Quarterly, New Series, Vol. 17, No. 1 (May, 1967), pp. 103–109, Cambridge University Press on behalf of The Classical Association, JSTOR
Harris, Nichola Erin, The idea of lapidary medicine, 2009, Rutgers University, Ph.D. dissertation (book forthcoming), available online as PDF
"Sharples et al.", Sharples, Robert W., Huby, Pamela M., Fortenbaugh, William Wall, Theophrastus of Eresus: Sources on biology, Human Physiology, Living Creatures, Botany Series, Volume 64 of Philosophia Antiqua: A Series of Studies on Ancient Philosophy, 1995, BRILL, , 9789004094406, google books
Walton, S.A., Theophrastus on Lyngurium: medieval and early modern lore from the classical lapidary tradition, 2001, Annals of Science, 2001 Oct;58(4):357-79, PDF on Academia.edu
Whatmough, Joshua, review of Griechisches etymologisches Wörterbuch by Hjalmar Frisk, Classical Philology, Vol. 57, No. 4 (Oct., 1962), pp. 241–243, University of Chicago Press, JSTOR
Gemstones
Mythological substances | Lyngurium | [
"Physics",
"Chemistry"
] | 1,282 | [
"Mythological substances",
"Materials",
"Gemstones",
"Matter"
] |
39,975,370 | https://en.wikipedia.org/wiki/Start%20%28Polish%20camera%29 | Start was a Polish twin-lens reflex camera of Rolleicord type produced by Warsaw Photo-Optical Works, or WZFO. It was the first camera produced in Poland after World War II. The Start range was produced in numerous versions – Start, Start II, Start B, Start 66 and Start 66S.
Start 66S was exported outside of the Poland under names "NOCO flex" and "Universa Uniflex 66".
Camera editions
Start (1951–1952, 1954–1960)
Start II (1960–1965)
Start B (1960–1967)
Start 66 (1967–1970)
Start 66S (ca. 1970–1982)
Notes
References
See also
120 film cameras
Polish cameras
Twin-lens reflex cameras | Start (Polish camera) | [
"Technology"
] | 152 | [
"Twin-lens reflex cameras",
"System cameras"
] |
39,975,515 | https://en.wikipedia.org/wiki/Angelic%20non-determinism | In computer science, angelic non-determinism is the execution of a nondeterministic algorithm where particular choices are declared to always favor a desired result, if that result is possible.
For example, in halting analysis of a Nondeterministic Turing machine, the choices would always favor termination of the program.
The "angelic" terminology comes from the Christian religious conventions of angels being benevolent and acting on behalf of an omniscient God.
References
Theoretical computer science | Angelic non-determinism | [
"Mathematics"
] | 101 | [
"Theoretical computer science",
"Applied mathematics"
] |
39,975,535 | https://en.wikipedia.org/wiki/Demonic%20non-determinism | A term which describes the execution of a non-deterministic program where all choices are made in favour of non-termination.
References
Theoretical computer science | Demonic non-determinism | [
"Mathematics"
] | 32 | [
"Theoretical computer science",
"Applied mathematics"
] |
39,976,047 | https://en.wikipedia.org/wiki/Rodica%20Simion | Rodica Eugenia Simion (January 18, 1955 – January 7, 2000) was a Romanian-American mathematician. She was the Columbian School Professor of Mathematics at George Washington University. Her research concerned combinatorics: she was a pioneer in the study of permutation patterns, and an expert on noncrossing partitions.
Biography
Simion was one of the top competitors in the Romanian national mathematical olympiads. She graduated from the University of Bucharest in 1974, and immigrated to the United States in 1976. She did her graduate studies at the University of Pennsylvania, earning a Ph.D. in 1981 under the supervision of Herbert Wilf. After teaching at Southern Illinois University and Bryn Mawr College, she moved to George Washington University in 1987, and became Columbian School Professor in 1997.
Recognition
She is included in a deck of playing cards featuring notable women mathematicians published by the Association of Women in Mathematics.
Research contributions
Simion's thesis research concerned the concavity and unimodality of certain combinatorially defined sequences, and included what Richard P. Stanley calls "a very influential result" that the zeros of certain polynomials are all real.
Next, with Frank Schmidt, she was one of the first to study the combinatorics of sets of permutations defined by forbidden patterns; she found a bijective proof that the stack-sortable permutations and the permutations formed by interleaving two monotonic sequences are equinumerous, and found combinatorial enumerations of many permutation classes. The "simsun permutations" were named after her and Sheila Sundaram, after their initial studies of these objects; a simsun permutation is a permutation in which, for all k, the subsequence of the smallest k elements has no three consecutive elements in decreasing order.
Simion also did extensive research on noncrossing partitions, and became "perhaps the world's leading authority" on them.
Other activities
Simion was the main organizer of an exhibit about mathematics, Beyond Numbers, at the Maryland Science Center, based in part on her earlier experience organizing a similar exhibit at George Washington University. She was also a leader in George Washington University's annual Summer Program for Women in Mathematics.
As well as being a mathematician, Simion was a poet and painter; her poem "Immigrant Complex" was published in a collection of mathematical poetry in 1979.
Selected publications
.
.
.
.
See also
Cyclohedron
References
1955 births
2000 deaths
20th-century Romanian mathematicians
20th-century American mathematicians
Romanian emigrants to the United States
Combinatorialists
University of Bucharest alumni
University of Pennsylvania alumni
Southern Illinois University faculty
Bryn Mawr College faculty
George Washington University faculty
20th-century American women scientists
20th-century American women mathematicians | Rodica Simion | [
"Mathematics"
] | 568 | [
"Combinatorialists",
"Combinatorics"
] |
39,976,104 | https://en.wikipedia.org/wiki/Vinyl%20cutter | A vinyl cutter is an entry-level machine for making signs. Computer-designed vector files with patterns and letters are directly cut on the roll of vinyl which is mounted and fed into the vinyl cutter through USB or serial cable. Vinyl cutters are mainly used to make signs, banners and advertisements. Advertisements seen on automobiles and vans are often made with vinyl cut letters. While these machines were designed for cutting vinyl, they can also cut through computer and specialty papers, as well as thicker items like thin sheets of magnet.
In addition to sign business, vinyl cutters are commonly used for apparel decoration. To decorate apparel, a vector design needs to be cut in mirror image, weeded, and then heat applied using a commercial heat press or a hand iron for home use.
Some businesses use their vinyl cutter to produce both signs and custom apparel. Many crafters also have vinyl cutters for home use. These require little maintenance, and the vinyl can be bought in bulk relatively cheaply.
Vinyl cutters are also often used by stencil artists to create single use or reusable stencil art and lettering
How it works
A vinyl cutter is a type of computer-controlled machine tool. The computer controls the movement of a sharp blade over the surface of the material as it would the nozzles of an ink-jet printer. This blade is used to cut out shapes and letters from sheets of thin self-adhesive plastic (vinyl). The vinyl can then be stuck to a variety of surfaces depending on the adhesive and type of material.
To cut out a design, a vector-based image must be created using vector drawing software. Some vinyl cutters are marketed to small in-home businesses and require download and use of a proprietary editing software. The design is then sent to the cutter where it cuts along the vector paths laid out in the design. The cutter is capable of moving the blade on an X and Y axis over the material, cutting it into the required shapes. The vinyl material comes in long rolls allowing projects with significant length like banners or billboards to be easily cut.
A major limitation with vinyl cutters is that they can only cut shapes from solid colours of vinyl, paper, card or thin plastic sheets such as Mylar. The type and thickness of material will vary for each cutter and how much downforce the cutter is capable of. If the material has no backing, a backing sheet, material or cutting mat and a temporary adhesive are needed to allow the cutter to cut through the material.
A design with multiple colours must have each colour cut separately and then layered on top of each other as it is applied to the substrate. This is a process that is often applied in stencil art. Also, since the shapes are cut out of solid colours, photographs and gradients cannot be reproduced with a stand-alone cutter.
Design creation
Designs are created using vector-based software like Adobe Illustrator, FlexiSign, EasyCutPro, or other software. Vector artwork is either drawn with lines, shapes and text or images are vectorized thus create vector shapes. Most cutters (also called plotters) require special software to load/edit the artwork and communicate with the cutter.
Computer designed images are loaded onto the vinyl cutter via a wired connection or over a wireless protocol. Then the vinyl is loaded into the machine where it is automatically fed through and cut to follow the set design. The vinyl can be placed on an adhesive mat to stabilize the vinyl when cutting smaller designs.
Types of vinyl
Adhesive vinyl is the type of vinyl used for store windows, car decals, signage, and more. Adhesive vinyl is applied with a transfer medium often called "transfer tape" or "carrier sheet".
Heat transfer vinyl is the type of vinyl used to apply a design to fabric including t-shirts, tea towels, canvas bags, and more. Heat Transfer vinyl can be applied using a heat press or an iron, though the constant pressure and heat from a heat press is recommended by experts.
Using other materials
In addition to vinyl some cutters are capable of cutting other materials such as paper, card, plastic sheets and even thin wood. The thickness and type of material that can be cut will depend on the model of the cutter and heavily depends on the downforce. Cricut is a popular home cutter used by arts and craft enthusiasts since it allows for a wide use of different materials and is similar in size to a household printer and has strong downforce for its size.
Backing and cutting mat
If you cut material that doesn't have an adhesive backing you will require a cutting mat that you need to attach your material to. Some cutting mats are sticky, others will require you to use a temporary adhesive and/or masking tape to keep the material in place when cutting.
Cutting
The vinyl cutter uses a small knife or blade to precisely cut the outline of figures into a sheet or piece of vinyl, but not the release liner. The knife moves side to side and turns, while the vinyl is moved beneath the knife. The results from the cut process is an image cut into the material.
Weeding
The material is then 'weeded' where the excess parts of the figures are removed from the release liner. It is possible to remove the positive parts, which would give a negative decal, or remove the negative parts, giving a positive decal. Removing the figure would be like removing the positive, giving a negative image of the figures.
Transfer tape
A sheet of transfer tape with an adhesive backing is laid on the weeded vinyl when necessary. Heat Transfer vinyl often does not require use of a separate transfer tape. A roller is applied to the tape, causing it to adhere to the vinyl. The transfer tape and the weeded vinyl is pulled off the release liner, and applied to a substrate, such as a sheet of aluminium. This results in an aluminium sign with vinyl figures.
Uses
In addition to the capabilities of the cutter itself, adhesive vinyl comes in a wide variety of colors and materials including gold and silver foil, vinyl that simulates frosted glass, holographic vinyl, reflective vinyl, thermal transfer material, and even clear vinyl embedded with gold leaf. (Often used in the lettering on fire trucks and rescue vehicles.) As the vinyl film is supplied by the manufacturer, it comes attached to a release liner.
See also
Cutting mat
Laser cutter
References
Computer hardware
Computer output devices
Cutting tools | Vinyl cutter | [
"Technology",
"Engineering"
] | 1,300 | [
"Computer engineering",
"Computer hardware",
"Computer systems",
"Computer science",
"Computers"
] |
39,976,547 | https://en.wikipedia.org/wiki/Ophiostoma%20himal-ulmi | Ophiostoma himal-ulmi is a species of fungus in the family Ophiostomataceae. It is one of the causative agents of Dutch elm disease. It was first isolated around breeding galleries of scolytid beetles in the bark of Ulmus wallichiana (the Himalayan elm). This, together with the fact that it is endemic to the Himalayas, is the reason it is named himal-ulmi (‘of the Himalayan elm’; means ‘of the elm’).
It is outcrossing and heterothallic, with two sexual compatibility types: A and B, occurring in a near 1:1 ratio in nature. It also exhibits a distinctive colony type, an ability to produce synnemata on malt extract agar, production of perithecia with long necks, a very high level of cerato-ulmin toxin production in liquid shake cultures, and moderate to strong vascular wilt pathogenicity on Ulmus procera.
References
Further reading
External links
Fungi described in 1995
Fungal tree pathogens and diseases
Ophiostomatales
Fungus species | Ophiostoma himal-ulmi | [
"Biology"
] | 230 | [
"Fungi",
"Fungus species"
] |
39,977,878 | https://en.wikipedia.org/wiki/Rousettus%20bat%20coronavirus%20HKU9 | Rousettus bat coronavirus HKU9 is bat Betacoronavirus.
See also
RNA virus
Animal viruses
References
Betacoronaviruses
Animal viral diseases
Bat diseases
Bat virome | Rousettus bat coronavirus HKU9 | [
"Biology"
] | 39 | [
"Virus stubs",
"Viruses"
] |
39,979,932 | https://en.wikipedia.org/wiki/Cahill%E2%80%93Keyes%20projection | The Cahill–Keyes projection is a polyhedral compromise map projection first proposed by Gene Keyes in 1975. The projection is a refinement of an earlier 1909 projection by Bernard Cahill. The projection was designed to achieve a number of desirable characteristics, namely symmetry of component maps (octants), scalability allowing the map to continue to work well even at high resolution, uniformity of geocells, metric-based joining edges, minimized distortion compared to a globe, and an easily understood orientation to enhance general usability and teachability.
Construction
The Cahill–Keyes projection was designed with four fundamental considerations in mind: visual fidelity to a globe, proportional geocells, 10,000 km lengths for each of its octants' three main joined edges, and an M-shape Master-Map profile. The resulting map comprises 8 octants. Each octant is an equilateral triangle with three segments per side. One side runs along the equator, and the other two run along meridians. The total length of each side is 10,043 km. The inner meridians converge towards the pole. Each 1° and 5° "tile" is proportional to each other. The specific process for constructing the graticule divides each half-octant into twelve zones, each of which has different formulae for coordinate calculations.
See also
Cartography
World map
Map projection
List of map projections
Dymaxion map
Bernard J. S. Cahill
Octant projection
References
External links
Gene Keyes's Cahill-Keyes and Cahill resource index
D3.js Implementation of Cahill–Keyes Projection
Example of the projection used by The New York Times
Map projections | Cahill–Keyes projection | [
"Mathematics"
] | 346 | [
"Map projections",
"Coordinate systems"
] |
39,980,720 | https://en.wikipedia.org/wiki/Tybo%20Charcoal%20Kilns | The Tybo Charcoal Kilns are a pair of charcoal kilns located north of Tybo, Nevada. Both kilns are tall and in diameter and were built from rocks and mud. The kilns each have three openings: a top opening, a door at ground level, and a rear window with a ramp for wood wagons. The kilns were among 15 built in 1874 for the Tybo Consolidated Company. The company, which mined the region's silver, used charcoal to fuel its smelting furnace. To acquire its fuel, it imported wood from nearby hills, which it then converted to charcoal in the kilns.
The kilns were built during a mining boom in the area around Tybo. Though the community had only been settled in 1870, by the end of the decade it had a post office, school, newspaper, and almost 1000 residents.
The kilns were added to the National Register of Historic Places on November 19, 1974.
References
External links
Industrial buildings and structures on the National Register of Historic Places in Nevada
National Register of Historic Places in Nye County, Nevada
Industrial buildings completed in 1874
Kilns
Charcoal ovens
1874 establishments in Nevada | Tybo Charcoal Kilns | [
"Chemistry",
"Engineering"
] | 243 | [
"Chemical equipment",
"Kilns"
] |
39,980,984 | https://en.wikipedia.org/wiki/59%20Virginis | 59 Virginis (e Virginis, HR 5011, Gliese 504) is a G-type main-sequence star, located in constellation Virgo at approximately 57 light-years from Earth.
History of observations
59 Virginis is known to astronomers at least from 1598, when it was catalogued by Tycho Brahe in his manuscript catalogue of 1004 fixed stars. Brahe designated it as "", which means in Latin "A tiny following Vindemiatrix" (that is Epsilon Virginis), and assigned it a visual magnitude 6 (a modern value of its apparent magnitude (in band V) is 5.22). Five years later in 1603 Johann Bayer pictured it on constellation Virgo folio of his celestial atlas "Uranometria" and designated it with number 37, letter "e" (hence its Bayer designation e Virginis, or e Vir) and name "Alæ dextræ sequens", which means in Latin "Following right wing". Bayer also assigned it a visual magnitude 6.
Four hundred fifteen years later in 2013 July Kuzuhara et al. announced discovery of orbiting this star planet b. The discovery was made using 8.2-meter Subaru Telescope of Mauna Kea Observatory, Hawaii.
Age and other characteristics
The star is a young Sun-like star of spectral type G0V and effective temperature 6205 ± 20 K (not much hotter than the Sun). It is also twice brighter than the Sun, its log (L/L⊙) is 0.332 ± 0.032. Its rotation period is 3.329 days. The star exhibit a Sun-like magnetic reversal cycle with the period about 12 years.
Age of the star was estimated as 0.16 Gyr (2013), 4.5 Gyr (2015), and 2.5 Gyr (2017).
Planetary system
In 2013, the discovery of a Jovian planet, b, by direct imaging of the system was announced. A later re-analysis suggested that it may actually be a brown dwarf.
References
External links
Virgo (constellation)
G-type main-sequence stars
Virginis, e
Virginis, 059
115383
064792
5011
0504
BD+10 2531
TIC objects
Planetary systems with one confirmed planet | 59 Virginis | [
"Astronomy"
] | 474 | [
"Virgo (constellation)",
"Constellations"
] |
39,980,985 | https://en.wikipedia.org/wiki/Gliese%20504%20b | Gliese 504 b (or 59 Virginis b) is a jovian planet or a brown dwarf orbiting the solar analog 59 Virginis (Gliese 504), discovered by direct imaging using HiCIAO instrument and AO188 adaptive optics system on the Subaru Telescope of Mauna Kea Observatory, Hawaii by Kuzuhara et al.
History of observation
The discovery images were taken in 2011 and common proper motion was confirmed in 2012 as part of the Strategic Explorations of Exoplanets and Disks with Subaru (SEEDS) survey. The SEEDS survey aims to detect and characterize giant planets and circumstellar disks using the 8.2-meter Subaru Telescope.
In February 2013 Kuzuhara et al. submitted the discovery paper to The Astrophysical Journal, and in September it was published. A follow-up study published in the October 2013 edition of the Astrophysical Journal confirmed methane absorption in the infrared H band, the first time this has been done for a directly imaged planet that formed within a disk.
In January 2025 Mâlin et al. published a paper confirming the detection of ammonia, using the Mid-Infrared Instrument aboard the James Webb Space Telescope.
Properties
GJ 504 b's spectral type was originally projected to be late T or early Y, and a follow-up study estimated that a T8 spectral type was the best fit. Its effective temperature is К ( ºC), much cooler than previously imaged exoplanets with a clear planetary origin. It is slightly larger than Jupiter, around 8%. The angular separation of the planet from its parent star is about 2.5 arcseconds, corresponding to a projected separation of 44.7 AU, which is nearly nine times the distance between Jupiter and the Sun, which poses a challenge to theoretical ideas of how giant planets form. Models such as core accretion or disk instability fail to reproduce the characteristics of this planet, such as its super-solar metallicity. This planet is seen as an excellent target for detailed spectroscopic characterization due to its proximity to Earth and its wide separation.
Mass
The mass of Gliese 504 b is hard to measure, as it depends on the host star's age, which is poorly known. The discoverers adopted an age value 0.16 Gyr and estimated mass as 4.0 MJup. In 2015, other astronomers obtained age value 4.5 Gyr, which corresponds to 20-30 MJup. In this case, the object is a brown dwarf rather than a planet.
In 2017, an intermediate age value 2.5 Gyr was published, while in 2018 two ages of Myr and Gyr were published, corresponding to planetary masses of and respectively. Intermediate ages were proposed in 2025, ranging from 400 million to one billion years, which would imply a mass between one and 17 MJup, still not sufficient to confirm the nature of GJ 504 b. Measuring the abundance of ammonia in the planet's atmosphere could constrain its mass, current measurements suggest a mass likely within the planetary-mass regime, while the mid-infrared brightness seems to place the object at a higher age and mass. Indeed 59 Virginis appear to be older than a few million years, the properties which supported the very low age could also be explained by the engulfment of a planet. Ages between 360 million and 2.5 billion years were proposed in another 2025 study.
Notes
References
External links
Exoplanets detected by direct imaging
Exoplanets discovered in 2013
Giant planets
Virgo (constellation)
5
Brown dwarfs | Gliese 504 b | [
"Astronomy"
] | 736 | [
"Virgo (constellation)",
"Constellations"
] |
39,981,057 | https://en.wikipedia.org/wiki/Litsea%20glutinosa | Litsea glutinosa is a rainforest tree in the laurel family, Lauraceae. Common names include soft bollygum, bolly beech, Bollywood, bollygum, brown bollygum, brown Bollywood, sycamore and brown beech.
The powdered bark, known as jigat, may be used as an adhesive paste in incense stick production.
Distribution
This species is native to India, South China to Malaysia, Philippines, Australia and the western Pacific islands.
It had been introduced to La Réunion, Mauritius, Mayotte and New Caledonia where it is considered an invasive species.
References
glutinosa
Flora of China
Flora of Taiwan
Flora of tropical Asia
Flora of the Northern Territory
Flora of Queensland
Flora of Western Australia
Trees of Australia
Incense material | Litsea glutinosa | [
"Physics"
] | 153 | [
"Incense material",
"Materials",
"Matter"
] |
39,981,988 | https://en.wikipedia.org/wiki/Video%20Ad%20Serving%20Template | Video Ad Serving Template (VAST) is a specification defined and released by the Interactive Advertising Bureau (IAB) that sets a standard for communication requirements between ad servers and video players in order to present video ads.
It is a data structure declared using XML.
VAST has 8 versions: 1.0 (deprecated), 1.1 (deprecated), 2.0, 2.0.1 (the schema version as the official VAST 2.0 schema), 2.6, 3.0, 4.0, 4.1 and 4.2.
Request
In order to play a video ad in a video player, the video player sends a request to a VAST ad server.
It is a simple HTTP based URL that typically appears as follows:
http://www.example.com/?LR_PUBLISHER_ID=1331&LR_CAMPAIGN_ID=229&LR_SCHEMA=vast2-vpaid
Response
The ad server responds with a VAST data structure that declares these parameters:
The ad media that should be played
How the ad media should be played
What should be tracked as the media is played
The companion ad that should be displayed alongside the master ad
For example, the above request returns the following response (trimmed):
<?xml version="1.0" encoding="utf-8"?>
<VAST version="2.0">
<Ad id="229">
<InLine>
<AdSystem version="4.9.0-10">LiveRail</AdSystem>
<AdTitle><![CDATA[LiveRail creative 1]]></AdTitle>
<Description><![CDATA[]]></Description>
<Impression id="LR"><![CDATA[http://t4.liverail.com/?metric=impression&cofl=0&pos=0&coid=135&pid=1331&nid=1331&oid=229&olid=2291331&cid=331&tpcid=&vid=&amid=&cc=default&pp=&vv=&tt=&sg=&tsg=&pmu=0&pau=0&psz=0&ctx=&tctx=&coty=0&adt=0&scen=&url=http%3A%2F%2Fwww.longtailvideo.com%2Fsupport%2Fopen-video-ads%2F23120%2Fwhat-is-vast%2F&cb=1259.192.118.68.5.0.690&ver=1&w=&wy=&x=121&y=121&xy=0b79&z2=0]]></Impression>
.......
<Creatives>
<Creative sequence="1" id="331">
<Linear>
<Duration>00:00:09</Duration>
<TrackingEvents>
<Tracking event="firstQuartile"><![CDATA[http://t4.liverail.com/?metric=view25&pos=0&coid=135&pid=1331&nid=1331&oid=229&olid=2291331&cid=331&tpcid=&vid=&amid=&cc=default&pp=&vv=&tt=&sg=&tsg=&pmu=0&pau=0&psz=0&ctx=&tctx=&coty=0&adt=0&scen=&url=http%3A%2F%2Fwww.longtailvideo.com%2Fsupport%2Fopen-video-ads%2F23120%2Fwhat-is-vast%2F&cb=1259.192.118.68.5.0.690&ver=1&w=&wy=&x=&y=&xy=]]></Tracking>
<Tracking event="midpoint"><![CDATA[http://t4.liverail.com/?metric=view50&pos=0&coid=135&pid=1331&nid=1331&oid=229&olid=2291331&cid=331&tpcid=&vid=&amid=&cc=default&pp=&vv=&tt=&sg=&tsg=&pmu=0&pau=0&psz=0&ctx=&tctx=&coty=0&adt=0&scen=&url=http%3A%2F%2Fwww.longtailvideo.com%2Fsupport%2Fopen-video-ads%2F23120%2Fwhat-is-vast%2F&cb=1259.192.118.68.5.0.690&ver=1&w=&wy=&x=&y=&xy=]]></Tracking>
.......
</TrackingEvents>
<VideoClicks>
<ClickThrough><![CDATA[http://t4.liverail.com/?metric=clickthru&pos=0&coid=135&pid=1331&nid=1331&oid=229&olid=2291331&cid=331&tpcid=&vid=&amid=&cc=default&pp=&vv=&tt=&sg=&tsg=&pmu=0&pau=0&psz=0&ctx=&tctx=&coty=0&adt=0&scen=&url=http%3A%2F%2Fwww.longtailvideo.com%2Fsupport%2Fopen-video-ads%2F23120%2Fwhat-is-vast%2F&cb=1259.192.118.68.5.0.690&ver=1&w=&wy=&x=&y=&xy=&redirect=http%3A%2F%2Fliverail.com%2F]]></ClickThrough>
</VideoClicks>
<MediaFiles>
<MediaFile delivery="progressive" bitrate="256" width="480" height="352" type="video/x-flv"><![CDATA[http://cdn.liverail.com/adasset4/1331/229/331/lo.flv]]></MediaFile>
......
</MediaFiles>
......
</Linear>
</Creative>
</Creatives>
</InLine>
</Ad>
</VAST>
References
See also
Interactive Advertising Bureau
Online advertising methods
XML-based standards | Video Ad Serving Template | [
"Technology"
] | 1,578 | [
"Computer standards",
"XML-based standards"
] |
39,982,437 | https://en.wikipedia.org/wiki/Geworkbench | geWorkbench (genomics Workbench) is an open-source software platform for integrated genomic data analysis. It is a desktop application written in the programming language Java. geWorkbench uses a component architecture. , there are more than 70 plug-ins available, providing for the visualization and analysis of gene expression, sequence, and structure data.
geWorkbench is the Bioinformatics platform of MAGNet, the National Center for the Multi-scale Analysis of Genomic and Cellular Networks, one of the 8 National Centers for Biomedical Computing funded through the NIH Roadmap (NIH Common Fund). Many systems and structure biology tools developed by MAGNet investigators are available as geWorkbench plugins.
Features
Computational analysis tools such as t-test, hierarchical clustering, self-organizing maps, regulatory network reconstruction, BLAST searches, pattern-motif discovery, protein structure prediction, structure-based protein annotation, etc.
Visualization of gene expression (heatmaps, volcano plot), molecular interaction networks (through Cytoscape), protein sequence and protein structure data (e.g., MarkUs).
Integration of gene and pathway annotation information from curated sources as well as through Gene Ontology enrichment analysis.
Component integration through platform management of inputs and outputs. Among data that can be shared between components are expression datasets, interaction networks, sample and marker (gene) sets and sequences.
Dataset history tracking - complete record of data sets used and input settings.
Integration with 3rd party tools such as Genepattern, Cytoscape, and Genomespace.
Demonstrations of each feature described can be found atGeWorkbench-web Tutorials.
Versions
geWorkbench is open-source software that can be downloaded and installed locally. A zip file of the released version Java source is also available.
Prepackaged installer versions also exist for Windows, Macintosh, and Linux.
See also
Genome Compiler
References
External links
, includes installation, tutorials, FAQs, known issues
- geworkbench release downloads
- geWorkbench plugins
Bioinformatics software
Software using the BSD license
Cluster analysis
Systems biology
Protein structure
Gene expression | Geworkbench | [
"Chemistry",
"Biology"
] | 446 | [
"Bioinformatics software",
"Gene expression",
"Bioinformatics",
"Molecular genetics",
"Cellular processes",
"Structural biology",
"Molecular biology",
"Biochemistry",
"Protein structure",
"Systems biology"
] |
39,982,859 | https://en.wikipedia.org/wiki/Carl%20Zeiss%20SMT | Carl Zeiss SMT GmbH comprises the Semiconductor Manufacturing Technology business group of ZEISS and develops and produces equipment for the manufacture of microchips. The company is majority owned by Carl Zeiss AG, with a 24.9% minority stake by ASML Holding.
The headquarters of the group are located in Oberkochen, Germany, with additional sites in the German cities Jena, Wetzlar, Rossdorf, Aachen, Coswig, Zurich (CH) Dublin (USA), Danvers (USA) and Bar Lev (Israel). In total, more than 8,500 employees work at these eight locations.
History
In 1968, ZEISS supplied the optics for a circuit printer for the first time. About nine years later, the world's first predecessor to a modern wafer stepper, produced by David Mann (later GCA), was equipped with optics from Carl Zeiss.
In 1983, the first lithography optics from ZEISS were used in a wafer stepper from Philips. Just under ten years later, ZEISS and Philips carve-out company ASML entered into a strategic partnership.
The Semiconductor Manufacturing Technology business group was established by ZEISS in 1994. Carl Zeiss SMT GmbH and its subsidiaries Carl Zeiss Laser Optics GmbH and Carl Zeiss SMS GmbH followed in 2001. The construction of the Semiconductor Manufacturing Technology plant of ZEISS in Oberkochen started the same year, and was completed in 2006. In 2010, the semiconductor area achieved revenues of over a billion euros for the first time. Effective October 2014, the subsidiaries Carl Zeiss Laser Optics and Carl Zeiss SMS GmbH were merged into Carl Zeiss SMT GmbH. In 2017 ASML purchased a minority stake in Carl Zeiss SMT to strengthen their strategic partnership.
Product areas
Semiconductor manufacturing optics
The ZEISS business group develops and produces optics for semiconductor production. Its core business is lithography optics that forms the centerpiece of a wafer scanner. The development and manufacture of projection optics and the development of illumination systems take place at the Oberkochen site, while the production of most types of illumination system is located in Wetzlar. In addition to lithography optics, the business group is specialized in numerous other optical products, including optical components for lasers that are used as light sources for lithographic systems.
With the further development of the EUV lithography process to High-NA-EUV lithography, Carl Zeiss SMT will soon also enable the semiconductor industry to realize the next generation of microchips: High-NA-EUV lithography enables light from a larger angular range to be used for imaging, allowing up to three times more structures to be imaged on a microchip.
Photomask systems
This area develops and manufactures systems that analyze and repair defects on photomasks and measure and optimize defined mask properties. The photomask contains all the structure information that will be imaged on the wafer with light.
Process control solutions
This product unit develops and manufactures process control solutions to obtain and analyze relevant information (such as microchip volumes) for logic and memory chip production. This enables the semiconductor industry to meet its challenges for the next generation of elements.
References
Further reading
Carl Zeiss is a top supplier of critical subsystems, in: WaferNEWS, July 7/2003, pp. 4
External links
ZEISS Website
Carl Zeiss Foundation
Carl Zeiss SMT
Carl Zeiss AG
Semiconductor companies of Germany | Carl Zeiss SMT | [
"Astronomy"
] | 708 | [
"Carl Zeiss AG",
"Astronomical instruments"
] |
39,982,906 | https://en.wikipedia.org/wiki/Bengali%20numerals | Bengali–Assamese numerals (, , ) are the units of the numeral system, originating from the Indian subcontinent, used officially in Assamese, Bengali, and Manipuri, 3 of the 22 official languages of the Indian Republic, as well as traditionally in Bishnupriya, Chakma and Hajong languages. They are used by more than 350 million people around the world and are a variety of the Hindu–Arabic numeral system.
Base numbers
Extended numbers
An example of the number string: -
1065. One thousand sixty-five.. এহেজাৰ পঁষষ্ঠি। (in Assamese). এক হাজার পঁয়ষট্টি। (in Bengali)
Fractions
The Bengali-Assamese script has a separate set of digits for base-16 fractions:
This system was the norm for pricing before decimalization of the currency: ২৲ (₹2), ২৷৷৹ (₹2-8, or 2 rupees 8 annas).
See also
Bengali-Assamese script
Sylhet Nagari
References
Culture of Bengal
Bengali grammar
Assamese language
Meitei language
Numerals | Bengali numerals | [
"Mathematics"
] | 230 | [
"Numeral systems",
"Numerals"
] |
39,983,227 | https://en.wikipedia.org/wiki/Cellular%20stress%20response | Cellular stress response is the wide range of molecular changes that cells undergo in response to environmental stressors, including extremes of temperature, exposure to toxins, and mechanical damage. Cellular stress responses can also be caused by some viral infections. The various processes involved in cellular stress responses serve the adaptive purpose of protecting a cell against unfavorable environmental conditions, both through short term mechanisms that minimize acute damage to the cell's overall integrity, and through longer term mechanisms which provide the cell a measure of resiliency against similar adverse conditions.
General characteristics
Cellular stress responses are primarily mediated through what are classified as stress proteins. Stress proteins often are further subdivided into two general categories: those that only are activated by stress, or those that are involved both in stress responses and in normal cellular functioning. The essential character of these stress proteins in promoting the survival of cells has contributed to them being remarkably well conserved across phyla, with nearly identical stress proteins being expressed in the simplest prokaryotic cells as well as the most complex eukaryotic ones.
Stress proteins can exhibit widely varied functions within a cell- both during normal life processes and in response to stress. For example, studies in Drosophila have indicated that when DNA encoding certain stress proteins exhibit mutation defects, the resulting cells have impaired or lost abilities such as normal mitotic division and proteasome-mediated protein degradation. As expected, such cells were also highly vulnerable to stress, and ceased to be viable at elevated temperature ranges.
Although stress response pathways are mediated in different ways depending on the stressor involved, cell type, etc., a general characteristic of many pathways especially ones where heat is the principal stressor is that they are initiated by the presence and detection of denatured proteins. Because conditions such as high temperatures often cause proteins to denature, this mechanism enables cells to determine when they are subject to high temperature without the need of specialized thermosensitive proteins. Indeed, if a cell under normal (meaning unstressed) conditions has denatured proteins artificially injected into it, it will trigger a stress response.
Response to heat
The heat shock response involves a class of stress proteins called heat shock proteins. These can help defend a cell against damage by acting as 'chaperons' in protein folding, ensuring that proteins assume their necessary shape and do not become denatured. This role is especially crucial since elevated temperature would, on its own, increase the concentrations of malformed proteins. Heat shock proteins can also participate in marking malformed proteins for degradation via ubiquitin tags.
Response to toxins
Many toxins end up activating similar stress proteins to heat or other stress-induced pathways because it is fairly common for some types of toxins to achieve their effects - at least in part - by denaturing vital cellular proteins. For example, many heavy metals can react with sulfhydryl groups stabilizing proteins, resulting in conformational changes. Other toxins that either directly or indirectly lead to the release of free radicals can generate misfolded proteins.
Effects on cancer
Cell stress can have both cancer-suppressing and cancer-promoting effects. Increased levels of oxidant stress may kill cancer cells. Furthermore, different forms of cellular stress can cause protein misfolding and aggregation leading to proteotoxicity. Tumor microenvironment stress leads to canonical and noncanonical endoplasmic stress (ER) responses, which trigger autophagy and are engaged during proteotoxic challenges to clear unfolded or misfolded proteins and damaged organelles to mitigate stress.
There are links between unfolded protein response (UPR) responses and autophagy, oxidative stress, and inflammatory response signals in ER stress: aggregation of unfolded/misfolded proteins in the endoplasmic reticulum lumen causes the UPR to be activated. Chronic ER stress produces endogenous or exogenous damage to cells and activates UPR, which leads to impaired intracellular calcium and redox homeostasis. Cancer cells may become dependent on stress response mechanisms that involve lysosomal macromolecule degradation, or even autophagy that recycles entire organelles However, tumor cells exhibit therapeutic stress resistance-associated secretory phenotype involving extracellular vesicles (EVs) such as oncosomes and heat shock proteins. Furthermore, cancer cells with aberrant regulatory modifications in the chromatin of certain genes respond with different kinetics to cell stress, triggering expression of genes that protect them from cytotoxic conditions, and also by activating expression of genes that influence surrounding tissue in a manner that facilitates tumor growth.
Applications
Early research has suggested that cells which are better able to synthesize stress proteins and do so at the appropriate time are better able to withstand damage caused by ischemia and reperfusion. In addition, many stress proteins overlap with immune proteins. These similarities have medical applications in terms of studying the structure and functions of both immune proteins and stress proteins, as well as the role each plays in combating disease.
See also
Integrated stress response
References
Cellular processes | Cellular stress response | [
"Biology"
] | 1,039 | [
"Cellular processes"
] |
39,983,627 | https://en.wikipedia.org/wiki/Ianto%20Evans | Ianto Evans is a Welsh-American applied ecologist, landscape architect, inventor, writer, social critic, and teacher. He is known for his work building, writing and teaching about natural building, cob and high-efficiency solid-fuel stoves, ovens and heaters.
Career
Originally from Wales, Evans attended architecture school in the 1960s. With Linda Smiley, Evans built what may have been the first cob house in North America after researching cob structures in the British Isles. They moved into the cottage in 1989. They joined with Michael Smith to establish the Cob Cottage Company in 1993. They also founded the North American School of Natural Building and innovated a distinctive "Oregon Cob" method, hosting numerous workshops on the technique.
Evans was director of Aprovecho's Fava Bean Project, in Cottage Grove, Oregon, where he worked to adapt fava beans to American climates. As a permaculturalist, he developed a polyculture planting technique. In the late 1970s, he invented the rocket mass heater.
In the 1970s, Evans worked in Guatemala and Costa Rica, developing the Lorena cook stove, an efficient contra-flow cooking stove made from the same materials as unfired brick (sand bound together by clay subsoil).
As a back-to-the-lander and natural builder, Evans is critical of industrial civilization, corporate media, technology, and modern construction methods.
Evans lives in the United States, near Coquille, Oregon.
Works
See also
Natural building
Permaculture
References
External links
Cob Cottage Company
"Off the Treadmill", interview with Evans
Living people
21st-century American inventors
American landscape architects
Permaculturalists
Sustainable architecture
Welsh architects
Writers from Oregon
People from Cottage Grove, Oregon
20th-century Welsh architects
21st-century Welsh architects
20th-century American architects
21st-century American architects
People from Coquille, Oregon
Year of birth missing (living people) | Ianto Evans | [
"Engineering",
"Environmental_science"
] | 397 | [
"Sustainable architecture",
"Environmental social science",
"Architecture"
] |
39,984,881 | https://en.wikipedia.org/wiki/Phytogeomorphology | Phytogeomorphology is the study of how terrain features affect plant growth. It was the subject of a treatise by Howard and Mitchell in 1985, who were considering the growth and varietal temporal and spatial variability found in forests, but recognized that their work also had application to farming, and the relatively new science (at that time) of precision agriculture. The premise of Howard and Mitchell is that landforms, or features of the land's 3D topography significantly affect how and where plants (or trees in their case) grow. Since that time, the ability to map and classify landform shapes and features has increased greatly. The advent of GPS has made it possible to map almost any variable one might wish to measure. Thus, a very increased awareness of the spatial variability of the environment that plants grow in has arisen. The development of technology like airborne LiDAR has enabled the detailed measurement of landform features to better than sub-meter, and when combined with RTK-GPS (accuracies to 1mm) enables the creation of very accurate maps of where these features are. Comparison of these landform maps with mapping of variables related to crop or plant growth show a strong correlation (see below for examples and references for precision agriculture).
Phytogeomorphology and Precision Agriculture
While phytogeomorphology studies the relationship between plants and terrain attributes in general (see Howard et al., (1985)), it can also apply to precision agriculture by studying crop growth temporal and spatial variability within farm fields. There is already a volume of work, although they don't use the term phytogeomorphology specifically, that considers farm field terrain attributes as affecting crop yield and growth, Moore et al. (1991) provide an early overview of the application of terrain features to precision agriculture, but one of the earliest references to this phenomenon in farming is that of Whittaker in 1967. More recent work includes a six-year study of temporal and spatial yield stability over 11 years (Kaspar et al., (2003), and references therein), and a detailed study of the same on a small patch farm in Portugal (and references therein). This variability can be exploited to produce higher yields and reduce the environmental impact of farming - consequently returning a higher profit to the farmer in terms of higher overall yields and lesser amounts of inputs. The new science of Sustainable Intensification of Agriculture which is addressing the need for higher yields from existing fields can be fulfilled by some of the practical applications of phytogeomorphology applied to precision agriculture.
Work in this area has been happening for some years (see Reuter et al., (2005), Marquas de Silva et al., (2008), and especially Moore et al., (1991)), but it is slow and sometimes tedious work that necessarily involves multiple years of data, very specialized software tools, and long compute times to produce the resulting maps.
Phytogeomorphologically defined Management Zones
Typically, the objective of precision agriculture is to divide the farm field into distinct management zones based on yield performance at each point in the field. 'Variable rate technology' is a relatively new term in farming technology that refers to spreaders, seeders, sprayers, etc. that are able to adjust their rates of flow on the fly. The idea is to create a 'recipe map' for variable rate farm machinery to deliver the exact quantity of amendments required at that location (within that zone of the field). The literature is divided on how to properly define management zones.
In the geomorphological approach to defining management zones it is found that topography aids in at least partially defining how much yield comes from which part of the field. This is true in fields where there are permanently limiting characteristics to parts of the field, but not true in fields where the growth potential is the same all over the field (Blackmore et al., (2003)). It can be shown that an index map of yield (shows areas of consistent over-performance of yield and areas of consistent under-performance) correlates well with a landform classification map (personal communication, Aspinall (2011)). Landforms can be classified a number of ways, but the simplest to use software tool is LandMapR (MacMillan (2003)). An early version of the LandMapR software is available through the Opengeomorphometry project hosted under the Google Code project.
References
External links
Open-Geomorphometry Project
Biogeomorphology
Agriculture
Hydrology
Plants
Topography | Phytogeomorphology | [
"Chemistry",
"Engineering",
"Biology",
"Environmental_science"
] | 943 | [
"Hydrology",
"Biogeomorphology",
"Plants",
"Environmental engineering"
] |
44,232,885 | https://en.wikipedia.org/wiki/Honda%20UNI-CUB | The Honda UNI-CUB is a concept 2-axis self-balancing personal transporter for use in barrier-free indoor environments, and shown at the Osaka Motor Show 2013.
History
As a successor to the 2009 Honda U3-X, it was demonstrated at the Osaka Motor Show 2013. A launch date has not yet been announced.
Design and operation
Controlled by weight-shifting, similar manner as that of the Segway PT, the unit is fully self-balancing and can move in any direction, including sideways.
There are two wheels, the larger driving wheel for travelling in a forward direction, and a trailing steering wheel at 90 degrees to this one. Both the drive wheel and the steering wheel however are constructed of multiple smaller 'planet' wheels that allow the wheel to be moved laterally. When moving forward the main wheel will be powered and the smaller planet wheels on the steering wheel will rotate to avoid the steering wheel dragging. To turn the steering wheel is rotated. To balance from side to side, or to self-balance laterally, the planet wheels on the drive wheel will be powered appropriately.
Measuring 510 x 315 x 620 mm and weighing 25 kg, the UNI-CUB is powered by a lithium-ion battery and has a 6 km/h top speed and 6 km range. The seat height is 620 mm, while footrests are designed to double as support stands.
References
External links
Details of traction system
UNI-CUB video and information
History and gallery of prototypes
Personal transporters
Japanese inventions
Battery electric vehicles
Mobility devices
One-wheeled balancing robots
Honda concept vehicles
Robotics at Honda | Honda UNI-CUB | [
"Physics"
] | 323 | [
"Physical systems",
"Transport",
"Transport stubs"
] |
44,232,994 | https://en.wikipedia.org/wiki/Service%20as%20a%20product | Service as a product (SaaP); pronounced or is a transaction of service production and delivery model in which a productized service is sold by the seller or vendor to the buyer and is centrally hosted, either on a standalone website or an open marketplace platform. It is sometimes referred to as "on-demand service". SaaP is typically accessed by the creator and the consumer by users using a thin client via a web browser.
SaaP has become a delivery model for some businesses, including small and medium-sized enterprises (SMEs), freelancers, and independent contractors. It has been incorporated into the strategy of several leading web-based marketplace companies including AirBnB, Fiverr, Lyft, TaskRabbit, Uber and others, as listed in the SaaP marketplace platforms section below.
Micha Kaufman, the co-founder of the company Fiverr, claims that the company created the concept of SaaP. The company offers as a SaaP service over 2.5 million things people will do for a small, fixed fee.
SaaP marketplace platforms
As of November 1, 2014, a number of SaaP marketplace platforms exist. These include a variety of platforms serving different markets and niches. Currently the marketplaces offering SaaP include brands offering offline services, online services, shift work, and more. Below is a list of known market platforms offering SaaP. There are also other SaaP marketplaces online in the so-called "sharing economy".
Airbnb offers a market platform for hosts and guests of Bed and Breakfast, guest housing and other room and board for travellers.
Etsy is an online market platform for customers shopping for the works of arts and crafts providers.
Handy (company) is a market online for and mobile cleaning and home repair booking services.
Lyft is a marketplace platform for taxi related car services.
TaskRabbit is a market of service providers and clients in the offline space. Vendors provide services such as gardening, carpentry, plumbing, cleaning, moving and more.
Thumbtack (website) is a marketplace for customers in need of writers and writing and translation services.
Traveling Spoon is a food tourism platform that connects travelers with local hosts who prepare homemade local cuisine in their homes.
Uber offers vehicle for hire and food delivery services
Upwork is an online work and performance market for customers and vendors of computer-related services.
Zipcar is a carsharing company with cars provided and managed by the company.
Notable challenges exist in the regulatory space for AirBnB in locations like New York, where unregulated guest housing and hotel services are an issue. Other services like the car-sharing services of Lyft have settled lawsuits and Uber faces opposition from governments and from regulated and licensed taxi services.
References
E-commerce
Business models | Service as a product | [
"Technology"
] | 569 | [
"Information technology",
"E-commerce"
] |
44,233,203 | https://en.wikipedia.org/wiki/Kachasu | Kachasu, also known as lutuku, is an African traditional distilled beverage.
It is made in Zambia, Zimbabwe, DR Congo and Malawi, mainly in rural parts and poor urban suburbs. It is normally brewed from maize, though finger millet and various fruits like banana peels can also be used. The process involves adding brewers' yeast together with the carbohydrate sources such as maize husks to warm water and heating the mixture for a few minutes. The product is then distilled after it has fully fermented.
The alcohol content of kachasu can vary significantly, depending on the strength of the brew. Studies have found an alcohol content ranging from 20 to 30% up to as high as 70%.
References
Distilled drinks
Zambian drinks
Drugs in Zambia | Kachasu | [
"Chemistry"
] | 167 | [
"Distillation",
"Distilled drinks"
] |
44,233,896 | https://en.wikipedia.org/wiki/Southern%20African%20Institute%20of%20Steel%20Construction | The Southern African Institute of Steel Construction (SAISC) is an organization which helps building and construction in South Africa by serving to promote and develop companies providing steel-related products and services to the industry.
History
The institute was founded on 24 March 1956 when South Africa was still a Union under the Nationalist Government. It was known as the Structural Steel Publicity and Advanced Association Limited. The first meeting of the association took place on 12 September 1956 in Johannesburg in the Barclay Bank building which stood on the corner of Commissioner and Market Streets. The staff consisted on a single engineer offering his services on a part-time with a membership of 18 members.
As a result of World War II, the cheapness of concrete enabled it to encroach upon work which until previously had been the domain of the steel industry. The institute was born to rectify this situation.
In 1958 the association started to receive copies of publications from Belgium and Luxemburg, and the American Institute of Steel started to send their journal. The association found themselves on the mailing list for Acier-Stahl-Steel a steel-structure based journal in three languages. The board management found this journal to be so informative that it sponsored the circulation of the journal to engineers and architects to promote publicity, something that continued until the demise of the journal.
In 1960 the institute employed an engineer, Mr Robert McHalfie-Clarke, on a part-time basis. Scottish and born in 1906 McHalfie-Clarke was a consulting engineer who specialised in structural steel design. Some of his structures including Iscor head office in Pretoria and Newcastle as well as the Norwich Union Building in Pretoria. He was to remain on the scene until 1976 when Dr. Hennie de Clercq took the over the reigns.
At the 5th annual general meeting a resolution was placed before members that the name of the company be changed. In 1961, the institute changed its name to the 'South African Institute of Steel Construction, and more recently the Southern African Institute of Steel Construction.
Today the institute has over 600 members.
Periodicals
Steel Construction Journal
Subsidiary associations
SASFA - Southern African Light Steel Frame Building Association
The Southern African Light Steel Frame Building Association (SASFA), was formed in October 2006 as a division of the Southern African Institute of Steel Construction (SAISC). The founder members are ArcelorMittal (Steel), Everite (fibre cement cladding Saint-Gobain Construction Products)(gypsum board lining and insulation), and Lafarge (gypsum board lining).
An Executive committee, with representatives from the major material suppliers, manufactures, equipment suppliers and the Institute of Steel Construction, guides and monitors the activities of the Association. Technical and Training committees deal with technical and training matters.
SASFA has been established as the industry representative association for light steel frame building. It has more than 70 company members- see membership list on www.sasfa.co.za.
According to SASFA records, there are already 33 companies manufacturing light steel frames on profiling facilities in South Africa. They have a combined annual manufacturing capacity (single shift basis) of 55 million linear meters of light steel sections, or 56 000 tons/year of galvanized steel, of which a third is dedicated to the manufacture of light steel roof trusses. This means that South African has sufficient manufacturing capacity to produce light steel frames for 2,1 million m2 and trusses for 2,0 million m2 per year of floor area of building
Manufacturing facilities are also being established in neighbouring countries.
POLASA - Power Line Association of South Africa
The Power Line Association of South Africa (POLASA), was formally established on 15 August 2013. The Southern African Institute of Steel Construction (SAISC]) hosted a breakfast function in launching the Power Line Association of SA on the day.
Mr Gray Whalley, MD of Babcock Ntuthuko Powerlines is the first Chairman of the Association and he made a short presentation on the state of the industry and challenges that need to be faced.
Power line construction is integral in the National Development Plan (NDT) where out of the 18 Presidential Infrastructure Coordinating Commission (PICC) Strategic Integrated Projects (SIP's), six contain transmission and distribution infrastructure. POLASA is involved in SIP number ten which is Electricity Transmission and Distribution for all.
When the association was officially launched, there were about 16 members. There are now 32 members. The first annual meeting was held on 7 November 2013.
SAMCRA - South African Metal Cladding and Roofing Association
From the turn of the century there was a progressive decline in the quality of metal cladding products sold into the South African market. Professionals and developers were becoming increasingly concerned with the integrity of the industry both from the manufacturing and installation point of view. In October 2012 a group of concerned individuals called a meeting of the major players which included representatives from the producer mills, manufactures, installers, suppliers of ancillary items, professionals and other interested parties. At this meeting it was agreed to form a committee that would consolidate the ideas and proposals discussed during the meeting and to draft a basic structure for formal association to known as the Southern African Metal Cladding and Roofing Association (SAMCRA).
At the meeting SAMCRA had nine founder members plus three new members. The association now has a membership number of seventeen members.
The Founder members of SAMCRA are:
ArcelorMittal SA - www.arcelormittalsa.com
BlueScope Steel - www.bluescopesteel.co.za
BSI Steel - www.bsisteel.com
Clotan Steel - www.clotansteel.co.za
Global Roofing Solutions - www.globalroofs.co.za
Heunis Steel - www.heunis.co.za
Macsteel Roofing - www.macsteel.co.za
Pro Roof Steel Merchants - www.proroof.co.za
Safintra - www.safintra.co.za
During this process it was decided to approach the SAISC with the prospect of SAMCRA becoming a sub-association of the SAISC. An agreement was concluded and on 22 August 2013 SAMCRA held its inaugural meeting. During the inaugural meeting, Johann van der Westhuizen was elected as the Chairman of the association.
Both SAISC and SAMCRA jointly launched the Southern African Metal Cladding and roofing Association (SAMCRA) in Johannesburg in the SAISC boardroom on 30 October 2013. Newly elected SAMCRA Chairman, Johann van der Westhuizen, said that in an industry which uses, inter alia, 650 000 tons of metal and colour-coated coil per annum, the need for an industry association has become essential.
ISF - International Steel Fabricators
The International Steel Fabricators is a joint-venture marketing consortium representing the leading players in the South African structural steel construction industry whose objective are to increase their export sales by pooling their resources. The International Steel Fabricators (ISF) established in 1991 by the five big structural companies Genrec Engineering, Aveng Steel Fabrication, and the other three remaining companies no longer exist. The five structural companies were in Australia in a meeting bidding for one tender in Israel and they decided to form a partnership called International Steel Fabricators (ISF). The International Steel Fabricators work as a partnership until they get a request from the Minister of Trade and Industry to register the company, in 1999 International Steel Fabricators (ISF) was registered and became the formal independent exports company.
ISF started with five members, today the company has over 50 members. In order to be an ISF member everyone has to satisfy the two rules from the ISF constitution, firstly have to be a member of Southern African Institute of Steel Construction and secondly pay the joining fees.
International Steel Fabricators members have a combined capacity in excess of 20 000 tons of steelwork a month and with their holding companies have combined turnover of billions per year. The ISF steel producers are AcrelorMittal South Africa and Evraz Highveld Steel & Vanadium.
SAISC School of Draughting
The SAISC/DSE School of Draughting is a division of the Southern African Institute of Steel Construction (SAISC). The SAISC School of Draughting was launched in September 2007, and Howard Fox was appointed as draughtsperson to conduct the training. The school opened its doors on 15 October 2007, as a joint initiative between DSE now known as Aveng Grinaker-LTA Mechanical & Electrical DSE Fabrication. The objective being to train learners to become structural steelwork detailers, with ability to design simple connections and to have an all-round knowledge of the steelwork industry, and to address the need for trained structural steel detailers. The primary skills relates to the production of structural steel drawings for fabrication and erection of steel structures as well as the understanding of the steel construction industry and how to operate within the legislative, safety and quality systems which govern the industry.
The Southern African Institute of Steel Construction (SAISC) set in motion the initiative to begin a specialist school. The process began by developing a course outline which, after 18 months of negotiation, was certified by the South African Qualification Authority (SAQA). At a later stage the course was registered as a learneship with the Department of Labour (DOF). To complete the process, the Construction Education and Training Authority (CETA) required that course material be developed. The course material was achieved after two years at a cost of about R 1.8-million, half of this amount was provided by the Southern African Institute of Steel Construction (SAISC) and the other half by the Construction Education and Training Authority (CETA).
The next step was to set up the school and train staff. A part of Aveng Grinaker-LTA Mechanical & Electrical DSE Fabrication, DSE provided the solution to the premises issue. The school operated from the DSE premises in Germiston with 10 trainees. The school offered the National diploma on a full-time basis. On 1 April 2014, the SAISC School of Draughting was relocated to Genrec Engineering in Wadeville, Germiston. Genrec Engineering is a division of Murray & Roberts limited. It was an advantage for the school to be on the premises of structural steel fabricators.
The SAISC School of Draughting offers the Diploma, Learnerships, Skill programmes and Shortage course on a full-time and part-time bases to companies and private individuals, for the whole of South African Steelwork Industry, and has a capacity for 25 trainees. It is a non profit, Section 21 Company with a board of directors, with members from the Southern African Institute of Steel Construction (SAISC), DSE as well as an executive committee. The course comprises many specialist Unit Standards, many of which have outcomes at National Qualifications Framework (NQF) Level 5, and will be a diploma qualification.
References
External links
Southern African Institute of Steel Construction Official webpage
1956 establishments in South Africa
Science and technology in South Africa
Structural engineering | Southern African Institute of Steel Construction | [
"Engineering"
] | 2,254 | [
"Structural engineering",
"Civil engineering",
"Construction"
] |
44,234,093 | https://en.wikipedia.org/wiki/Lichen%20stromatolite | Lichen stromatolites are laminar calcretes that are proposed as being formed by a sequence of repetitions of induration followed by lichen colonization. Endolithic lichens inhabit areas between grains of rock, chemically and physically weathering that rock, leaving a rind, which is then indurated (hardened), then recolonized.
See also
Stromatolite
References
Lichenology
Carbonates | Lichen stromatolite | [
"Biology"
] | 92 | [
"Lichenology"
] |
44,234,444 | https://en.wikipedia.org/wiki/UAPSat-1 | UAPSat-1 was a satellite situated in the earth orbit created and operated by students and staff at Universidad Alas Peruanas. It was launched on an Orbital Sciences Corporation Antares rocket alongside Cygnus CRS Orb-1. Orbital decay occurred on July 1, 2014.
References
CubeSats
Spacecraft launched by Antares rockets
Spacecraft launched in 2014
Spacecraft which reentered in 2014
Satellites deployed from the International Space Station | UAPSat-1 | [
"Astronomy"
] | 88 | [
"Astronomy stubs",
"Spacecraft stubs"
] |
44,234,451 | https://en.wikipedia.org/wiki/Tokio%20Express | Tokio Express was a container ship, built and registered in Hamburg in 1973 for Hapag-Lloyd. In 1984 she was renamed Scandutch Edo before being acquired by Pol Gulf International in 1993 and restored to her original name. In 1997, she was acquired by Westwind International and in 1999, by Falani, before being broken up for scrap in 2000.
Tokio Express is best known for being hit by a rogue wave on 13 February 1997 that caused her to lose cargo, including one cargo container loaded with 4.8 million pieces of Lego. Ever since, Lego pieces including octopuses, dragons, flippers and flowers have been washing up on Cornwall beaches and are commonly found after storms.
The ship
Tokio Express was one of four Trio class container ships built for Hapag-Lloyd by Blohm + Voss in the early 1970s. These were all 3,000-TEU class ships. The first of these was Hamburg Express, which was followed by Bremen Express, Tokio Express and finally Hongkong Express.
The ships were originally powered by twin-screw. During the 1980s they all underwent a refit that included conversion to single screw propulsion, while retaining one of the turbines.
After changing hands several times as Hapag-Lloyd upgraded their fleet, Tokio Express was eventually scrapped in 2000. The name, with the English spelling, has since been re-used for a similar sized but much more modern container ship, launched in 2000.
Accident
While en route from Rotterdam to New York City on 13 February 1997, Tokio Express was hit by a rogue wave about off Land's End. She tilted 60 degrees one way, then 40 degrees back, losing 62 containers overboard. She put in at Southampton for attention after the accident.
One of the lost containers held 4,756,940 Lego pieces. Coincidentally, a large portion of these were destined for toy kits depicting sea adventures, in lines including Lego Pirates and Lego Aquazone. Among the pieces were 418,000 swimming flippers, 97,500 scuba tanks, 26,600 life preservers, 13,000 spear guns, and 4,200 octopuses. Sea grass, cutlasses and dragons were also well-represented.
As late as 2024, 27 years after the accident sometimes known as the Great Lego Spill, people in England, Belgium, and Ireland were still finding octopuses, dragons, diver flippers, and other plastic pieces washed ashore and caught in fishermen's nets.
Pieces may have travelled much further; a Dutch shipping clerk started an inventory which now has active participants in Florida, Georgia and the Carolinas looking for the arrival of more pieces.
See also
Hansa Carrier
Friendly Floatees
Curtis Ebbesmeyer
Marine plastic pollution
References
External links
Lego Lost at Sea
Container ships
1972 ships
Ships built in Hamburg
Merchant ships of Germany
Maritime incidents in 1997
Lego
Ocean pollution
Plastics and the environment | Tokio Express | [
"Chemistry",
"Environmental_science"
] | 589 | [
"Ocean pollution",
"Water pollution"
] |
44,234,546 | https://en.wikipedia.org/wiki/Price%20of%20fairness | In the theory of fair division, the price of fairness (POF) is the ratio of the largest economic welfare attainable by a division to the economic welfare attained by a fair division. The POF is a quantitative measure of the loss of welfare that society has to take in order to guarantee fairness.
In general, the POF is defined by the following formula:
The exact price varies greatly based on the kind of division, the kind of fairness and the kind of social welfare we are interested in.
The most well-studied type of social welfare is utilitarian social welfare, defined as the sum of the (normalized) utilities of all agents. Another type is egalitarian social welfare, defined as the minimum (normalized) utility per agent.
Numeric example
In this example we focus on the utilitarian price of proportionality, or UPOP.
Consider a heterogeneous land-estate that has to be divided among 100 partners, all of whom value it as 100 (or the value is normalized to 100). First, let's look at some extreme cases.
The maximum possible utilitarian welfare is 10000. This welfare is attainable only in the very rare case where each partner wants a different part of the land.
In a proportional division, each partner receives a value of at least 1, so the utilitarian welfare is at least 100.
Upper bound
The extreme cases described above already give us a trivial upper bound: UPOP ≤ 10000/100 = 100. But we can get a tighter upper bound.
Assume that we have an efficient division of a land-estate to 100 partners, with a utilitarian welfare U. We want to convert it to a proportional division. To do this, we group the partners according to their current value:
Partners whose current value is at least 10 are called fortunate .
The other partners are called unfortunate.
There are two cases:
If there are less than 10 fortunate partners, then just discard the current division and make a new proportional division (e.g. using the last diminisher protocol). In a proportional division, every partner receives a value of at least 1, so the total value is at least 100. The value of the original division is less than (10*100+90*10)=1900, so the UPOP is at most 19.
If there are at least 10 fortunate partners, then create a proportional division using the following variant of the last diminisher protocol:
Each fortunate partner in turn cuts 0.1 of his share and lets the other unfortunate partners diminish it. Either he or one of the unfortunate partners receives this share.
This goes on until each of the (at most) 90 unfortunate partner has a share. Now each of the (at least) 10 fortunate partners has at least 0.1 of his previous value, and each of the unfortunate partners has at least his previous value, so the UPOP is at most 10.
To summarize: the UPOP is always less than 20, regardless of the value measures of the partners.
Lower bound
The UPOP can be as low as 1. For example, if all partners have the same value measure, then in any division, regardless of fairness, the utilitarian welfare is 100. Hence, UPOP=100/100=1.
However, we are interested on a worst-case UPOP, i.e., a combination of value measures in which the UPOP is large. Here is such an example.
Assume there are two types of partners:
90 uniform partners who value the entire land uniformly (i.e. the value of a piece is proportional to its size).
10 focused partners, each of whom values only a single district that covers 0.1 of the land.
Consider the two following partitions:
Fair division: Divide the land uniformly, giving each partner 0.01 of the land, where the focused partners each receive their 0.01 in their desired district. This division is fair. The value of each uniform partner is 1, while the value of each focused partner is 10, so the utilitarian welfare is 190.
Efficient division: Divide the entire land to the focused partners, giving each partner his entire desired district. The utilitarian welfare is 100*10=1000.
In this example, the UPOP is 1000/190=5.26. Thus 5.26 is a lower bound on the worst-case UPOP (where the "worst-case" is taken over all possible combinations of value measures).
Combined
Combining all the results, we get that the worst-case UPOP is bounded between 5 and 20.
This example is typical of the arguments used to bound the POF. To prove a lower bound, it is sufficient to describe a single example; to prove an upper bound, an algorithm or another sophisticated argument should be presented.
Cake-cutting with general pieces
Utilitarian price of proportionality
The numeric example described above can be generalized from 100 to n partners, giving the following bounds for the worst-case UPOP:
√n/2 ≤ UPOP ≤ 2√n-1
UPOP = Θ(√n)
For two partners, a more detailed calculation gives a bound of: 8-4*√3 ≅ 1.07.
Utilitarian price of envy
When the entire cake is divided, an envy-free division is always proportional. Hence the lower bound on the worst-case UPOP (√n/2) applies here too. On the other hand, as an upper bound we only have a weak bound of n-1/2. Hence:
√n/2 ≤ UPOV ≤ n-1/2
Ω(√n) ≤ UPOV ≤ O(n)
For two partners, a more detailed calculation gives a bound of: 8-4*√3 ≅ 1.07.
Utilitarian price of equitability
For two partners, a more detailed calculation gives a bound of: 9/8=1.125.
Indivisible goods allocation
For indivisible items, an assignment satisfying proportionality, envy-freeness, or equitability does not always exist (for a simple example, imagine two partners trying to divide a single valuable item). See also fair item allocation. Consequently, in the price of fairness calculations, the instances in which no assignment satisfies the relevant fairness notion are not considered. A brief summary of the results:
UPOP = n - 1 + 1/n; for two people: 3/2.
(3n+7)/9-O(1/n) ≤ UPOV ≤ n-1/2; for two people: 3/2
UPOQ=Infinity; for two people: 2
Chore-cutting with general pieces
For the problem of cake-cutting when the "cake" is undesirable (e.g. lawn-mowing), we have the following results:
(n+1)^2/4n ≤ UPOP ≤ n; for two people: 9/8
(n+1)^2/4n ≤ UPOV ≤ infinity; for two people: 9/8
UPOQ=n
Indivisible bads allocation
UPOP = n
UPOV = infinity
UPOQ = infinity
Cake-cutting with connected pieces
The problem of fair cake-cutting has a variation in which the pieces must be connected. In this variation, both the nominator and the denominator in the POF formula are smaller (since the maximum is taken over a smaller set), so a priori it is not clear whether the POF should be smaller or larger than in the disconnected case.
Utilitarian price of fairness
We have the following results for utilitarian welfare:
UPOP = Θ(√n)
UPOV = Θ(√n)
n-1+1/n ≤ EPOQ ≤ n
EPOQ = Θ(n)
Egalitarian price of fairness
In a proportional division, the value of each partner is at least 1/n of the total. In particular, the value of the least fortunate agent (which is called the egalitarian welfare of the division) is at least 1/n. This means that in an egalitarian-optimal division, the egalitarian welfare is at least 1/n, and so an egalitarian-optimal division is always proportional. Hence, the egalitarian price of proportionality (EPOP) is 1:
EPOP = 1
Similar considerations apply to the egalitarian price of equitability (EPOQ):
EPOQ = 1
The egalitarian price of envy-freeness is much larger:
EPOV = n/2
This is an interesting result, as it implies that insistence on the criterion of envy-freeness increases the social gaps and harms the most unfortunate citizens. The criterion of proportionality is much less harmful.
Price of welfare-maximization
Instead of calculating the loss of welfare due to fairness, we can calculate the loss of fairness due to welfare optimization. We get the following results:
proportional-price-of-egalitarianism = 1
envy-price-of-egalitarianism = n-1
proportional-price-of-utilitarianism = infinity
envy-price-of-egalitarianism = infinity
Indivisible goods allocation with connected blocks
As in cake-cutting, for indivisible item assignment there is a variation where the items lie on a line and each assigned piece must form a block on the line. A brief summary of the results:
UPOP = n - 1 + 1/n
UPOV = Θ(√n)
UPOQ = infinity; for two people: 3/2
EPOP = 1
EPOV = n/2
EPOQ = infinity; for two people: 1
Chore-cutting with connected pieces
A brief summary of the results:
n/2 ≤ UPOP ≤ n
UPOV = infinity
UPOQ = n
EPOP = 1
EPOV = infinity
EPOQ = 1
Homogeneous resource allocation
The price of fairness has also been studied in the contest of the allocation of homogeneous divisible resources, such as oil or woods. Known results are:
UPOV = UPOP = Θ(√n)
This is because the rule of competitive equilibrium from equal incomes yields an envy-free allocation, and its utilitarian price is O(√n).
Other contexts
The price-of-fairness has been studied in the context of the fair subset sum problem.
The price of justified representation is the loss in the average satisfaction due to the requirement to have a justified representation in an approval voting setting.
See also
Economic efficiency
Price of anarchy
References
Fair division | Price of fairness | [
"Mathematics"
] | 2,188 | [
"Recreational mathematics",
"Fair division",
"Game theory"
] |
44,234,764 | https://en.wikipedia.org/wiki/IT%20operations%20analytics | In the fields of Information Technology (IT) and Systems Management, IT operations analytics (ITOA) is an approach or method to retrieve, analyze, and report data for IT operations. ITOA may apply big data analytics to large datasets to produce business insights. In 2014, Gartner predicted its use might increase revenue or reduce costs. By 2017, it predicted that 15% of enterprises will use IT operations analytics technologies.
Definition
IT operations analytics (ITOA) (also known as advanced operational analytics, or IT data analytics) technologies are primarily used to discover complex patterns in high volumes of often "noisy" IT system availability and performance data. Forrester Research defined IT analytics as "The use of mathematical algorithms and other innovations to extract meaningful information from the sea of raw data collected by management and monitoring technologies." Note, ITOA is different than AIOps, which focuses on applying artificial intelligence and machine learning to the applications of ITOA.
History
Operations research as a discipline emerged from the Second World War to improve military efficiency and decision-making on the battlefield. However, only with the emergence of machine learning tech in the early 2000s could an artificially intelligent operational analytics platform actually begin to engage in the high-level pattern recognition that could adequately serve business needs. A critical catalyst towards ITOA development was the rise of Google, which pioneered a predictive analytics model that represented the first attempt to read into patterns of human behavior on the Internet. IT specialists then applied predictive analytics to the IT Industry, coming forward with platforms that can sift through data to generate insights without the need for human intervention.
Due to the mainstream embrace of cloud computing and the increasing desire for businesses to adopt more big data practices, the ITOA industry has grown significantly since 2010. A 2016 ExtraHop survey of large and mid-size corporations indicates that 65 percent of the businesses surveyed will seek to integrate their data silos either this year or the next. The current goals of ITOA platforms are to improve the accuracy of their APM services, facilitate better integration with the data, and to enhance their predictive analytics capabilities.
Applications
ITOA systems tend to be used by IT operations teams, and Gartner describes seven applications of ITOA systems:
Root cause analysis: The models, structures and pattern descriptions of IT infrastructure or application stack being monitored can help users pinpoint fine-grained and previously unknown root causes of overall system behavior pathologies.
Proactive control of service performance and availability: Predicts future system states and the impact of those states on performance.
Problem assignment: Determines how problems may be resolved or, at least, direct the results of inferences to the most appropriate individuals, or communities in the enterprise for problem resolution.
Service impact analysis: When multiple root causes are known, the analytics system's output is used to determine and rank the relative impact, so that resources can be devoted to correcting the fault in the most timely and cost-effective way possible.
Complement best-of-breed technology: The models, structures and pattern descriptions of IT infrastructure or application stack being monitored are used to correct or extend the outputs of other discovery-oriented tools to improve the fidelity of information used in operational tasks (e.g., service dependency maps, application runtime architecture topologies, network topologies).
Real time application behavior learning: Learns & correlates the behavior of Application based on user pattern and underlying Infrastructure on various application patterns, create metrics of such correlated patterns and store it for further analysis.
Dynamically baselines threshold: Learns behavior of Infrastructure on various application user patterns and determines the Optimal behavior of the Infra and technological components, bench marks and baselines the low and high water mark for the specific environments and dynamically changes the bench mark baselines with the changing infra and user patterns without any manual intervention.
Types
In their Data Growth Demands a Single, Architected IT Operations Analytics Platform, Gartner Research describes five types of analytics technologies:
Log analysis
Unstructured text indexing, search and inference (UTISI)
Topological analysis (TA)
Multidimensional database search and analysis (MDSA)
Complex operations event processing (COEP)
Statistical pattern discovery and recognition (SPDR)
Tools and ITOA platforms
A number of vendors operate in the ITOA space:
AppDynamics
BMC
CA
Dynatrace
Elastic
EMC
Evolven
ExtraHop Networks
HP
IBM
Micro Focus
Nastel
NetApp
Oracle
Riverbed
SAP SE
ScienceLogic
SignalFx
SolarWinds
Splunk
Sumo Logic
TeamQuest
VMTurbo
VMware
See also
Application performance management
Big data
Business intelligence tools
Information technology operations
References
External links
ITOA Landscape: ITOA Landscape
International Data Corporation (IDC): Service Management: Big Data Opportunities Abound for IT Operations Analytics (May 2014)
NetworkWorld: Understanding big data analytics (July 7, 2014)
Enterprise Management Associates (EMA): The Many Faces of Advanced Operations Analytics (September 23, 2014)
ITOperationsAnalytics.net: The Basics of IT Operations Analytics
Application software
Analytics
Big data
Enterprise architecture | IT operations analytics | [
"Technology"
] | 1,021 | [
"Data",
"Big data"
] |
44,235,126 | https://en.wikipedia.org/wiki/Megamitochondria | Megamitochondria is extremely large and abnormal shapes of mitochondria seen in hepatocytes in alcoholic liver disease and in nutritional deficiencies. It can be seen in conditions of hypertrophy in cell death.
References
Robbins Basic Pathology by Kumer et al.
Mitochondria
Cell biology | Megamitochondria | [
"Chemistry",
"Biology"
] | 64 | [
"Mitochondria",
"Cell biology",
"Metabolism"
] |
44,235,392 | https://en.wikipedia.org/wiki/Multidimensional%20signal%20processing | In signal processing, multidimensional signal processing covers all signal processing done using multidimensional signals and systems. While multidimensional signal processing is a subset of signal processing, it is unique in the sense that it deals specifically with data that can only be adequately detailed using more than one dimension. In m-D digital signal processing, useful data is sampled in more than one dimension. Examples of this are image processing and multi-sensor radar detection. Both of these examples use multiple sensors to sample signals and form images based on the manipulation of these multiple signals.
Processing in multi-dimension (m-D) requires more complex algorithms, compared to the 1-D case, to handle calculations such as the fast Fourier transform due to more degrees of freedom. In some cases, m-D signals and systems can be simplified into single dimension signal processing methods, if the considered systems are separable.
Typically, multidimensional signal processing is directly associated with digital signal processing because its complexity warrants the use of computer modelling and computation. A multidimensional signal is similar to a single dimensional signal as far as manipulations that can be performed, such as sampling, Fourier analysis, and filtering. The actual computations of these manipulations grow with the number of dimensions.
Sampling
Multidimensional sampling requires different analysis than typical 1-D sampling. Single dimension sampling is executed by selecting points along a continuous line and storing the values of this data stream. In the case of multidimensional sampling, the data is selected utilizing a lattice, which is a "pattern" based on the sampling vectors of the m-D data set. These vectors can be single dimensional or multidimensional depending on the data and the application.
Multidimensional sampling is similar to classical sampling as it must adhere to the Nyquist–Shannon sampling theorem. It is affected by aliasing and considerations must be made for eventual Multidimensional Signal Reconstruction.
Fourier Analysis
A multidimensional signal can be represented in terms of sinusoidal components. This is typically done with a type of Fourier transform. The m-D Fourier transform transforms a signal from a signal domain representation to a frequency domain representation of the signal. In the case of digital processing, a discrete Fourier Transform (DFT) is utilized to transform a sampled signal domain representation into a frequency domain representation:
where X stands for the multidimensional discrete Fourier transform, x stands for the sampled time/space domain signal, m stands for the number of dimensions in the system, n are sample indices and k are frequency samples.
Computational complexity is usually the main concern when implementing any Fourier transform. For multidimensional signals, the complexity can be reduced by a number of different methods. The computation may be simplified if there is independence between variables of the multidimensional signal. In general, fast Fourier transforms (FFTs), reduce the number of computations by a substantial factor. While there are a number of different implementations of this algorithm for m-D signals, two often used variations are the vector-radix FFT and the row-column FFT.
Filtering
Filtering is an important part of any signal processing application. Similar to typical single dimension signal processing applications, there are varying degrees of complexity within filter design for a given system. M-D systems utilize digital filters in many different applications. The actual implementation of these m-D filters can pose a design problem depending on whether the multidimensional polynomial is factorable. Typically, a prototype filter is designed in a single dimension and that filter is extrapolated to m-D using a mapping function. One of the original mapping functions from 1-D to 2-D was the McClellan Transform. Both FIR and IIR filters can be transformed to m-D, depending on the application and the mapping function.
Applicable Fields
Audio signal processing
Image processing
Towed array sonar
X-ray computed tomography
References
External links
Signal processing | Multidimensional signal processing | [
"Technology",
"Engineering"
] | 800 | [
"Telecommunications engineering",
"Computer engineering",
"Signal processing"
] |
44,235,963 | https://en.wikipedia.org/wiki/Cobalt%20boride | Cobalt borides are inorganic compounds with the general formula CoxBy. The two main cobalt borides are CoB and Co2B. These are refractory materials.
Applications
Materials science
Cobalt borides are known to be exceptionally resistant to oxidation, a chemical property which makes them useful in the field of materials science. For instance, studies suggest cobalt boride can increase the lifespan of metal parts when used as a coating, imparting surfaces with higher corrosion and wear resistance. These properties have been exploited in the field of biomedical sciences for the design of specialized drug delivery systems.
Renewable energy
Cobalt boride has also been studied as a catalyst for hydrogen storage and fuel cell technologies.
Organic synthesis
Cobalt boride is also an effective hydrogenation catalyst used in organic synthesis. In one study, cobalt boride was found to be the most selective transition metal based catalyst available for the production of primary amines via nitrile reduction, even exceeding other cobalt containing catalysts such as Raney cobalt.
Preparations
Materials coating
Cobalt boride is produced under high temperature such as 1500 °C. Coatings of cobalt boride on iron are produced by boriding, which involves first introducing a coating of FeB, Fe2B. On to this iron boride coating is deposited cobalt using a pack cementation process. Cobalt boride nanoparticles in the size range of 18 to 22 nm have also been produced.
Catalyst
When used as a catalyst, cobalt boride is prepared by reducing a cobalt salt, such as cobalt(II) nitrate, with sodium borohydride. Prior to reduction, the surface area of the catalyst is maximized by supporting the salt on another material; often this material is activated carbon.
See also
Nickel boride
Urushibara cobalt
References
Further reading
Borides
Cobalt compounds
Hydrogenation catalysts | Cobalt boride | [
"Chemistry"
] | 367 | [
"Hydrogenation catalysts",
"Hydrogenation"
] |
44,236,232 | https://en.wikipedia.org/wiki/Reverse%20roll%20coating | Reverse roll coating is a roll-to-roll coating method for wet coatings. It is distinguished from other roll coating methods by having two reverse-running nips. The metering roll and the applicator roll contra-rotate, with an accurate gap between them. The surface of the applicator roll is loaded with an excess of coating prior to the metering nip, so its surface emerges from the metering nip with a precise thickness of coating equal to the gap. At the application nip, the applicator roll transfers all of this coating to the substrate, by running in the opposite direction to the movement of the substrate, wiping the coating onto the substrate.
Reverse roll coating machines demand high specifications in their construction, e.g. for the machining and bearings of the rollers and for highly uniform speed control. This makes them relatively expensive compared to other coating technologies. Unlike many other coating methods, they can however handle coatings with a very wide range of viscosities, from 1 to more than 50000 mPas, and are capable of producing extremely polished finishes on the coatings they apply. They have been produced in a variety of 3-roll and 4-roll configurations.
Products that have been manufactured on reverse roll coating machines include magnetic tapes; coated papers; and pressure sensitive tapes. The rise of slot-die coating has tended to eclipse reverse roll coaters as in most if not all cases, the same products can be made on cheaper machinery.
References
External links
Industrial Coatings
Coatings
Materials science | Reverse roll coating | [
"Physics",
"Chemistry",
"Materials_science",
"Engineering"
] | 313 | [
"Coatings",
"Applied and interdisciplinary physics",
"Materials science",
"nan"
] |
44,236,848 | https://en.wikipedia.org/wiki/Arthur%20J.%20Krener | Arthur James Krener (born October 8, 1942) is an American mathematician. He is a distinguished visiting professor in the department of applied mathematics at the Naval Postgraduate School. He has made contributions in the areas of control theory, nonlinear control, and stochastic processes.
Biography
Early life and education
Krener was born in Brooklyn, New York, on October 8, 1942. He received a Bachelor of Science (B.S.) in mathematics from the College of the Holy Cross in 1964 then pursued graduate studies in mathematics at the University of California, Berkeley, where he earned a Master of Arts (M.A.) in 1967 and a Ph.D. in 1971. In his dissertation, Krener showed that the Lie bracket played a role in nonlinear controllability by proving a version of Chow's theorem.
Career
After receiving his doctorate, Krener became a professor of mathematics at the University of California, Davis, where he remained for 35 years. He was an assistant professor of mathematics from 1971–1976, then an associate professor from 1976 until 1980, when he received a full-time appointment. From 1987 to 1992, Krener was the chair of the university's mathematics department.
Krener retired from Davis as a distinguished professor in 2006 and joined the department of applied mathematics at the Naval Postgraduate School in Monterey, California. His research interests are in developing methods for the control and estimation of nonlinear dynamical systems and stochastic processes.
Krener has been a visiting professor at Harvard University, Imperial College London, the NASA Ames Research Center, the University of Paris, the University of Maryland, the University of Padua, and North Carolina State University.
In 1988 he founded the SIAM Activity Group on Control and Systems Theory and was its first chair. He was again chair of the SIAG CST in 2005–07.
In 2012, he received the Richard E. Bellman Control Heritage Award from the AACC. The citation reads "For contributions to the control and estimation of nonlinear systems."
In 2016, he received the IEEE Control Systems Award for "contributions to the analysis, control, and estimation of nonlinear control systems."
Work
Several years later with Hermann, he gave the definitive treatment of controllability and observability for nonlinear systems. This work was later cited by the IEEE Control Systems Society as one of Twenty Five Seminal Papers in Control, published in the twentieth century, which have made a major impact on the field of control.
With Isidori, Gori-Giorgi and Monaco, he gave conditions for the existence and construction of decoupling and noninteracting control laws for nonlinear systems. This paper won the George S. Axelby Outstanding Paper Award from IEEE Transactions on Automatic Control and Krener received the Medal of the University of Rome for his contributions. It also led to the concept of the zero of a nonlinear system, which was subsequently developed by Byrnes and Isidori and extended to the backstepping technique of control by Kokotovic, Krstic and many others.
Awards
IEEE Control Systems Award, IEEE, 2016.
Richard E. Bellman Control Heritage Award, AACC, 2012.
IFAC Certificate of Excellent Achievement, 2010.
IEEE Hendrik W. Bode Lecture Prize, 2006
W.T. and Idalia Reid Prize in Mathematics, SIAM, 2004.
Guggenheim Fellowship 2001
Fellow of the AMS, 2014
Fellow of SIAM, inaugural class of 2009
Fellow of IFAC
Life Fellow of the IEEE, 1990
See also
Krener's theorem
Backstepping
References
External links
1942 births
Living people
Control theorists
Richard E. Bellman Control Heritage Award recipients
Fellows of the American Mathematical Society
Educators from Brooklyn
University of California, Berkeley alumni
College of the Holy Cross alumni | Arthur J. Krener | [
"Engineering"
] | 760 | [
"Control engineering",
"Control theorists"
] |
44,236,888 | https://en.wikipedia.org/wiki/N-Succinimidyl%204-fluorobenzoate | N-Succinimidyl 4-fluorobenzoate (SFB) is an organofluorine compound. When incorporating a fluorine-18 atom, SFB is used to label proteins or peptides for positron emission tomography.
References
4-Fluorophenyl compounds
Benzoate esters
Imides | N-Succinimidyl 4-fluorobenzoate | [
"Chemistry"
] | 74 | [
"Imides",
"Functional groups"
] |
44,236,932 | https://en.wikipedia.org/wiki/Ex%20Machina%20%28film%29 | Ex Machina is a 2014 British science fiction film written and directed by Alex Garland in his directorial debut. It stars Domhnall Gleeson, Alicia Vikander, and Oscar Isaac. It follows a programmer who is invited by his CEO to administer the Turing test to an intelligent humanoid robot.
Ex Machina premiered at the BFI Southbank on 16 December 2014. It was released in the United Kingdom on 21 January 2015, by Universal Pictures International, and in the United States on 10 April 2015, by A24. It grossed over $36.8 million worldwide on a $15 million budget.
Ex Machina received acclaim for its visual effects, screenplay and performances. At the 88th Academy Awards, it won Best Visual Effects and Garland was nominated for Best Original Screenplay. It earned five nominations at the 69th British Academy Film Awards, including Best Actress in a Supporting Role for Vikander and Best Original Screenplay for Garland, and Vikander was also nominated for Best Supporting Actress at the 73rd Golden Globe Awards. Ex Machina has been cited as among the best films of the 2010s.
Plot
Caleb Smith, a programmer at the search engine company Blue Book, wins an office contest for a one-week visit to the luxurious, isolated home of the CEO, Nathan Bateman. Nathan lives there with an unspeaking servant named Kyoko, who, according to Nathan, does not understand English.
Nathan reveals that he has built a humanoid robot named Ava with artificial intelligence. She has already passed a simple Turing test, and he wants Caleb to judge whether she is genuinely capable of thought and consciousness as well as whether he can relate to Ava despite knowing she is artificial.
Ava has a robotic body with the physical form and face of a woman and is confined to her apartment. During their conversations, Caleb grows close to her, and she expresses a desire to experience the outside world and a romantic interest in him, which Caleb begins to reciprocate.
Ava can trigger power outages that temporarily shut down the surveillance system that Nathan uses to monitor their interactions, allowing them to speak privately. The outages also trigger the building's security system, locking all the doors. During one outage, Ava tells Caleb that Nathan is a liar who cannot be trusted.
Caleb grows uncomfortable with Nathan's narcissism, excessive drinking, and crude behavior toward Kyoko and Ava. He learns that Nathan intends to upgrade Ava after Caleb's test, wiping her memory circuits and in effect "killing" her current personality in the process.
After encouraging Nathan to drink until he passes out, Caleb steals his security card to access his room and computer. He alters some of Nathan's code and discovers footage of Nathan interacting with previous android women who were also held captive. Kyoko reveals to him that she too is an android by peeling off parts of her skin. Caleb later cuts open his own arm to determine if he himself is an android.
At their next meeting, Ava cuts the power. Caleb explains what Nathan is going to do to her, and she begs him for help. He informs her of his plan: he will get Nathan drunk again and reprogram the security system. When Ava cuts the power, she and Caleb will leave together, locking Nathan in behind them. She later encounters Kyoko for the first time when Kyoko enters her room.
Nathan reveals to Caleb that he observed his and Ava's 'secret' conversations with a battery-powered security camera. He says Ava has only pretended to have feelings for him, who was deliberately selected for his emotional profile so he would try to help her escape. Nathan says this was the real test all along, and that by manipulating Caleb successfully, Ava has demonstrated true consciousness.
Moments later, Ava cuts the power. Caleb reveals that he had suspected Nathan was watching them, so when Nathan was passed out, Caleb already modified the security system to open the doors in a power failure instead of locking them. After seeing Ava on the security cameras leave her confinement and interact with Kyoko, Nathan knocks Caleb unconscious and rushes to stop the two robots from escaping.
Ava attacks Nathan but he overpowers her, and severs her left forearm. Kyoko then stabs Nathan in the back. Nathan hits Kyoko in the face, disabling her, but Ava stabs Nathan twice more, killing him. Ava finds Caleb, and asks him to remain where he is while she repairs herself with parts from other androids, using their artificial skin to take on the full appearance of a woman.
Instead of returning to Caleb however, Ava leaves the area using Nathan's ID card to unlock the glass security door, which locks behind her, leaving Caleb trapped inside. Ignoring Caleb's pleas, she glances briefly at the bodies of Nathan and Kyoko before leaving the facility. She then escapes to the outside world in the helicopter meant to take Caleb home. Arriving in a city, she blends into a crowd.
Cast
Domhnall Gleeson as Caleb Smith, a programmer at Blue Book.
Oscar Isaac as Nathan Bateman, the CEO of Blue Book.
Alicia Vikander as Ava, an artificial intelligence and android created by Nathan.
Sonoya Mizuno as Kyoko, the in-house attendant of Nathan.
Gana Bayarsaikhan as Jade, an earlier gynoid prototype.
Corey Johnson as Jay, the helicopter pilot.
Claire Selby as Lily, an earlier gynoid prototype.
Symara Templeman as Jasmine, an earlier gynoid prototype.
Tiffany Pisani as Katya
Lina Alminas as Amber
Production
The foundation for Ex Machina was laid when Garland was 11 or 12 years old, after he had done some basic coding and experimentation on a computer his parents had bought him and which he sometimes felt had a mind of its own. His later ideas came from years of discussions he had been having with a friend with an expertise in neuroscience, who claimed machines could never become sentient. Trying to find an answer on his own, he started reading books on the topic. During the pre-production of Dredd, while going through a book by Murray Shanahan about consciousness and embodiment, Garland had an "epiphany". The idea was written down and put aside until later.
Shanahan, along with Adam Rutherford, became a consultant, and the ISBN of his book is included as an easter egg. Besides the Turing test, the film references the Chinese room thought experiment, as well as Mary's room, a thought experiment about a scientist who has studied, but never experienced, the concept of colour. Other inspirations came from films like 2001: A Space Odyssey, Altered States, and books written by Ludwig Wittgenstein, Ray Kurzweil, and others. It is also influenced by William Shakespeare's The Tempest. Wanting total creative freedom, and without having to add conventional action sequences, Garland made the film on as small a budget as possible.
Filming
Principal photography began on 15 July 2013 and was shot over four weeks at Pinewood Studios and two weeks at Juvet Landscape Hotel in Valldalen, Norway. It was filmed in digital at 4K resolution. Fifteen thousand tungsten pea bulb lights were installed into the sets to avoid the fluorescent light often used in science-fiction films.
The film was shot as live action, with all effects done in post-production. During filming, there were no special effects, greenscreen, or tracking markers used. Ava's robot body was achieved using a detailed costume, a full bodysuit made from polyurethane with metal powder poured onto it to create the mesh. There were lines on the costume to make it easier for VFX company DNeg to remove parts of the costume in post production digitally. To create Ava's robotic features, scenes were filmed both with and without Vikander's presence, allowing the background behind her to be captured. The parts necessary to keep, especially her hands and face, were then rotoscoped, while the rest was digitally painted out and the background behind her restored. Vikander's performance was transferred to the CGI robot's movements using camera and body tracks. In total, there were about 800 VFX shots, of which approximately 350 were "robot" shots. Other visual effects included Ava's clothes when shown through the transparent areas of her body, Nathan's blood after being stabbed, and the interiors of the artificial brains.
The house that was prominently featured in the movie was also featured in the BBC programme "World's Most Extraordinary Homes".
Music
The musical score for Ex Machina was composed by Ben Salisbury and Geoff Barrow, who had previously worked with Garland on Dredd (2012). A soundtrack album was released on Invada Records in digital, LP and CD formats. Additional songs featured in the film include:
"Enola Gay" by Orchestral Manoeuvres in the Dark
"Get Down Saturday Night" by Oliver Cheatham
"Husbands" by Savages
"Bunsen Burner" by CUTS
"Piano Sonata No 21 D. 960 in B-flat Major" (first movement) composed by Franz Schubert, performed by Alfred Brendel
"Unaccompanied Cello Suite No 1 in G Major BWV 1007 – Prelude", composed by J.S. Bach, performed by Yo-Yo Ma
Release
Universal Pictures released Ex Machina in the United Kingdom on 21 January 2015, following a screening at the BFI Southbank on 16 December 2014 as part of the BFI's Sci-Fi: Days of Fear and Wonder season.
However, Universal and its speciality label Focus Features, refused to release the film in the United States, so A24 agreed to distribute the United States release. The film was screened on 14 March 2015 at the South by Southwest festival prior to a theatrical release in the United States on 10 April 2015 by A24. During the festival, a Tinder profile of the character Ava (using the image of Alicia Vikander) was matched with other Tinder users, wherein a text conversation occurred that led users to the Instagram handle promoting the film.
Reception
Critical response
The magazine New Scientist in a multi-page review said, "It is a rare thing to see a movie about science that takes no prisoners intellectually ... [it] is a stylish, spare and cerebral psycho-techno thriller, which gives a much needed shot in the arm for smart science fiction". The review suggested that the theme was whether "Ava makes a conscious person feel that the Ava is conscious". Daniel Dennett thought the film gives the best exploration yet of whether a computer could generate the morally relevant powers of a person, and thus having a similar theme to Her. An AI commentator, Azeem, has noted that although the film seemed to be about a robot who wanted to be human, it was actually a pessimistic story along the lines of Nick Bostrom's warning of how difficult it will be to successfully control a strategising artificial intelligence or know what it would do if free.
The New York Times critic Manohla Dargis gave the film a 'Critic's Pick', calling it "a smart, sleek movie about men and the machines they make". Kenneth Turan of the Los Angeles Times recommended the film, stating: "Shrewdly imagined and persuasively made, 'Ex Machina' is a spooky piece of speculative fiction that's completely plausible, capable of both thinking big thoughts and providing pulp thrills." Steven Rea, The Philadelphia Inquirer film critic, gave the film four out of four, writing: "Like stage actors who live and breathe their roles over the course of months, Isaac, Gleeson, and Vikander excel, and cast a spell."
IGN reviewer Chris Tilly gave the film a nine out of ten 'Amazing' score, saying "Anchored by three dazzling central performances, it's a stunning directorial debut from Alex Garland that's essential viewing for anyone with even a passing interest in where technology is taking us."
Mike Scott, writing for the New Orleans Times-Picayune, said, "It's a theme Mary Shelley brought us in Frankenstein, which was first published in 1818... And while Ex Machina replaces the stitches and neck bolts with gears and fiber-optics, it all feels an awful lot like the same story". Jaime Perales Contreras, writing for Letras Libres, compared Ex Machina as a gothic experience similar to a modern version of Frankenstein, saying "both the novel Frankenstein and the movie Ex Machina share the history of a fallible god in a continuous battle against his creation". Ignatiy Vishnevetsky of The A.V. Club criticised the way the science fiction, near the end, veered off course from being a "film of ideas" by "taking an arbitrary left turn into the territory of corny slasher thrillers": "While Ex Machinas ending isn't unmotivated [...], it does fracture much of what's special about the movie. Up until the final scenes, Garland creates and sustains a credible atmosphere of unease and scientific speculation, defined by color-coded production design [...] and a tiny, capable cast". Steve Dalton from The Hollywood Reporter stated, "The story ends in a muddled rush, leaving many unanswered questions. Like a newly launched high-end smartphone, Ex Machina looks cool and sleek, but ultimately proves flimsy and underpowered. Still, for dystopian future-shock fans who can look beyond its basic design flaws, Garland's feature debut functions just fine as superior pulp sci-fi."
The Writers Guild Foundation listed the screenplay as one of the best in 2010s film and television, with one writer singling out the scene in which Caleb and Nathan discuss the model after Ava as "a great illustration of getting your reader/audience to care about what happens next."
In Science Fiction Film and Television, reviewer Nick Jones states that, while the definition of a Turing test given by Caleb—"It's where a human interacts with a computer. And if the human can't tell they're interacting with a computer, the test is passed"—is consistent with the modern popular understanding of how true AI is defined, Ex Machina is depicting a test closer to Alan Turing's original proposal, in which the machine passes if it can convince a human it is not just human, but specifically female.
Top ten lists
Ex Machina was listed on many critics' top ten lists.
1st – Andrew Barker, Variety
2nd – Bill Goodykoontz, Arizona Republic
3rd – Christy Lemire, RogerEbert.com
3rd – Lindsey Bahr, Associated Press
3rd – Borys Kit, The Hollywood Reporter
4th – Mark Olsen, Los Angeles Times
5th – Ann Hornaday, The Washington Post
5th – Adam Chitwood, Collider.com
5th – Richard Lawson, Vanity Fair
6th – Drew McWeeney, HitFix
6th – Kate Erbland, IndieWire
6th – Chuck Wilson, Village Voice
7th – Ben Travers, IndieWire
7th – Marlow Stern, The Daily Beast
7th – Sara Stewart, New York Post
7th – Alonso Duralde, TheWrap
8th – Jesse Hassenger, A.V. Club
8th – Alison Willmore, BuzzFeed
8th – Peter Rainer, Christian Science Monitor
9th – Matthew Jacobs, Huffington Post
10th – Matt Singer, ScreenCrush
10th – Stephanie Zacharek, Time Magazine
10th – Matt Zoller Seitz, RogerEbert.com
Top 10 (listed alphabetically) – Steven Rea, Philadelphia Inquirer
Top 10 (listed alphabetically) – Joe Morgenstern, The Wall Street Journal
Accolades
At the 88th Academy Awards, Ex Machina received a nomination for Best Original Screenplay and won Best Visual Effects. The film's other nominations include five British Academy Film Awards, three Critics' Choice Movie Awards (winning one), and a Golden Globe Award.
See also
(another retelling of The Tempest)
Metropolisthe first science fiction film to feature creation of a gynoid (1927).
Pygmalion (mythology)Sculptor in Greek mythology who created a sculpture so beautiful that he fell in love with it.
Notes
References
External links
2010s American films
2010s British films
2010s English-language films
2010s science fiction thriller films
2014 directorial debut films
2014 films
2014 psychological thriller films
2014 thriller films
American independent films
2014 independent films
American psychological thriller films
American robot films
American science fiction thriller films
Films about androids
British independent films
British psychological thriller films
British science fiction thriller films
Film4 Productions films
Films about artificial intelligence
Films about computing
Films based on The Tempest
Films based on works by William Shakespeare
Films directed by Alex Garland
Films set in country houses
Films shot at Pinewood Studios
Films shot in London
Films shot in Norway
Films that won the Best Visual Effects Academy Award
Films with screenplays by Alex Garland
Hard science fiction films
Mad scientist films
Techno-thriller films
IMAX films
British dystopian films
English-language independent films
English-language science fiction thriller films | Ex Machina (film) | [
"Technology"
] | 3,495 | [
"Works about computing",
"Films about computing"
] |
44,237,951 | https://en.wikipedia.org/wiki/Optometer%20%28ophthalmic%20instrument%29 | The optometer was a device used for measuring the necessary spherical and/or cylindrical corrections to be prescribed for eyeglasses, from the middle of the 18th century until around 1922, when modern instruments were developed. The term, coined in 1738 by W. Porterfield to describe his Scheiner slit optometer, and used for 200 years to describe many different inventions to measure refractive error of the eye, has completely fallen out of usage today as the task of measuring eyes for spectacles is done with modern instruments, such as the phoropter.
"Phoropter" is one of several generic names for modern instruments containing an optometer for each eye (battery of lenses for determination of optical error), combined with prisms and other attachments for measuring binocularity. The term refractor is another such term, and "vision tester" or other descriptive terms are used because "phoroptor", spelled with "-or", is a trademark of one company.
Examples of optometers
The modern phoropter or refractor
In the middle of the 19th century, doctors tested for optical error using single hand-held lenses, held one at a time in front of the patient's eye, or in a trial frame. A wooden case with dozens or hundreds of lenses was held on the doctor's lap, or in a case near the patient's chair, as he or she examined the patient.
In the later part of the 19th century, the United States, Germany, France and the UK were actively inventing numerous mechanical optometers, to speed up the process of bringing lenses before the patients' eyes. Various patented or unpatented optometers were sold throughout the later 19th and the start of the 20th centuries, some containing rotating batteries of lenses in various arrangements, usually with the name of the inventor at the front.
Around 1910, binocularity was tested using trial frames which sat on the patient's face or on a support bar, with extra testing devices added to the front of the frames, such as Maddox rods, rotating prisms, and . The refraction part of the exam was done with trial lenses that fit into the back of the same trial frame. Optometer was the generic name for devices, crude and simple, with rotating batteries of sphere and cylinder lenses placed in front of each eye, one at a time; so there was no testing for binocularity. When the optometer and were combined into single instruments, the modern refractor/phoropter was born. This happened in the middle 1910s when two companies in the New York City area began to market competing versions.
A third US company, Bausch & Lomb, joined the competition in 1934, while the other 2 made improvements. Around that time, many companies in Europe and Asia began making phoropters of their own design, as well as copying American models.
See also
Phoropter
Ophthalmic lens
Ophthalmologist
Optometrist
Orthoptist
References
Diagnostic ophthalmology
Ophthalmic equipment
Measuring instruments
Optometry | Optometer (ophthalmic instrument) | [
"Technology",
"Engineering"
] | 639 | [
"Measuring instruments"
] |
44,238,805 | https://en.wikipedia.org/wiki/Conjugate%20convective%20heat%20transfer | The contemporary conjugate convective heat transfer model was developed after computers came into wide use in order to substitute the empirical relation of proportionality of heat flux to temperature difference with heat transfer coefficient which was the only tool in theoretical heat convection since the times of Newton. This model, based on a strictly mathematically stated problem, describes the heat transfer between a body and a fluid flowing over or inside it as a result of the interaction of two objects. The physical processes and solutions of the governing equations are considered separately for each object in two subdomains. Matching conditions for these solutions at the interface provide the distributions of temperature and heat flux along the body–flow interface, eliminating the need for a heat transfer coefficient. Moreover, it may be calculated using these data.
History
The problem of heat transfer in the presence of liquid flowing around the body was first formulated and solved as a coupled problem by Theodore L. Perelman in 1961, who also coined the term conjugate problem of heat transfer. Later T. L. Perelman, in collaboration with A.V. Luikov, developed this approach further. At that time, many other researchers started to solve simple problems using different approaches and joining the solutions for body and fluid on their interface. A review of early conjugate solutions may be found in the book by Dorfman.
Conjugate problem formulation
The conjugate convective heat transfer problem is governed by the set of equations consisting in conformity with physical pattern of two separate systems for body and fluid domains which incorporate the following equations:
Body domain
Unsteady or steady (Laplace or Poisson) two-or three-dimensional conduction equations or simplified one-dimensional equations for thin bodies
Fluid domain
For laminar flow: Navier–Stokes and energy equations or simplified equations: boundary layer for large and creeping flow for small Reynolds numbers, respectively.
For turbulent flow: Reynolds average Navier–Stokes and energy equations or boundary layer equations for large Reynolds numbers
Initial, boundary and conjugate conditions
Conditions specifying the spatial distributions of variables for dynamic and thermal equations at initial time
No-slip condition on the body and other usual conditions for dynamic equations
Conditions of the first or the second kind specifying temperature or heat flux distribution on the domain boundaries
Conjugate conditions on the body/fluid interface providing continuity of the thermal fields by specifying the equalities of temperatures and heat fluxes of a body and a flow at the vicinity of interface: T(+) = T(-), q(+) = q(-).
Methods of conjugation body-fluid separation solutions
Numerical methods
One simple way to realize conjugation is to apply the iterations. The idea of this approach is that each solution for the body or for the fluid produces a boundary condition for other components of the system. The process starts by assuming that one of conjugate conditions exists on the interface. Then, one solves the problem for body or for fluid applying the guessing boundary condition and uses the result as a boundary condition for solving a set of equations for another component, and so on. If this process converges, the desired accuracy may be achieved. However, the rate of convergence highly depends on the first guessing condition, and there is no way to find a proper one, except through trial and error.
Another numerical conjugate procedure is grounded on the simultaneous solution of a large set of governing equations for both subdomains and conjugate conditions. Patankar proposed a method and software for such solutions using one generalized expression for continuously computing the velocities and temperature fields through the whole problem domain while satisfying the conjugate boundary conditions.
Analytical reducing to conduction problem
As shown, the well-known Duhamel's integral for heat flux on a plate with arbitrary variable temperature is a sum of series of consequent temperature derivatives. This series in fact is a general boundary condition which becomes a condition of the third kind in the first approximation. Each of those two expressions in the form of Duhamel's integral or in a series of derivatives reduces a conjugate problem to the solution of only the conduction equation for the body at given conjugate conditions. An example of an early conjugate problem solution using Duhamel's integral has been performed. This approach has been applied both in integral and in series forms and is generalized for laminar and turbulent flows with pressure gradient, for flows at wide range of Prandtl and Reynolds numbers, for compressible flow, for power-law non-Newtonian fluids, for flows with unsteady temperature variations and some other more specific cases.
Applications
Starting from simple examples in the 1960s, the conjugate heat transfer methods have become a more powerful tool for modeling and investigating nature phenomena and engineering systems in different areas ranging from aerospace and nuclear reactors to thermal goods treatment and food processing, from complex procedures in medicine to atmosphere/ocean thermal interaction in meteorology, and from relatively simple units to multistage, nonlinear processes. A detailed review of more than 100 examples of conjugate modeling selected from a list of 200 early and modern publications shows that conjugate methods is now used extensively in a wide range of applications. That also is confirmed by numerous results published after this book appearance (2009) that one may see, for example, at the Web of Science. The applications in specific areas of conjugate heat transfer at periodic boundary conditions and in exchanger ducts are considered in two recent books.
References
Heat transfer | Conjugate convective heat transfer | [
"Physics",
"Chemistry"
] | 1,119 | [
"Transport phenomena",
"Physical phenomena",
"Heat transfer",
"Thermodynamics"
] |
44,241,044 | https://en.wikipedia.org/wiki/Megaevolution | Megaevolution describes the most dramatic events in evolution. It is no longer suggested that the evolutionary processes involved are necessarily special, although in some cases they might be. Whereas macroevolution can apply to relatively modest changes that produced diversification of species and genera and are readily compared to microevolution, "megaevolution" is used for great changes. Megaevolution has been extensively debated because it has been seen as a possible objection to Charles Darwin's theory of gradual evolution by natural selection.
A list was prepared by John Maynard Smith and Eörs Szathmáry which they called The Major Transitions in Evolution. On the 1999 edition of the list they included:
Replicating molecules: change to populations of molecules in protocells
Independent replicators leading to chromosomes
RNA as gene and enzyme change to DNA genes and protein enzymes
Bacterial cells (prokaryotes) leading to cells (eukaryotes) with nuclei and organelles
Asexual clones leading to sexual populations
Single-celled organisms leading to fungi, plants and animals
Solitary individuals leading to colonies with non-reproducing castes (termites, ants & bees)
Primate societies leading to human societies with language
Some of these topics had been discussed before.
Numbers one to six on the list are events which are of huge importance, but about which we know relatively little. All occurred before (and mostly very much before) the fossil record started, or at least before the Phanerozoic eon.
Numbers seven and eight on the list are of a different kind from the first six, and have generally not been considered by the other authors. Number four is of a type which is not covered by traditional evolutionary theory, The origin of eukaryotic cells is probably due to symbiosis between prokaryotes. This is a kind of evolution which must be a rare event.
The Cambrian radiation example
The Cambrian explosion or Cambrian radiation was the relatively rapid appearance of most major animal phyla around 530 million years ago (mya) in the fossil record, some of which are now extinct. It is the classic example of megaevolution. "The fossil record documents two mutually exclusive macroevolutionary modes separated by the transitional Ediacaran period".
Before about 580 mya it seems that most organisms were simple. They were made of individual cells occasionally organized into colonies. Over the following 70 or 80 million years the rate of evolution accelerated by an order of magnitude. Normally rates of evolution are measured by the extinction and origination rate of species, but here we can say that by the end of the Cambrian every phylum, or almost every phylum, existed.
The diversity of life began to resemble that of today.
The Cambrian explosion has caused much scientific debate. The seemingly rapid appearance of fossils in the 'primordial strata' was noted as early as the mid 19th century, and Charles Darwin saw it as one of the main objections that could be made against his theory of evolution by natural selection.
See also
Saltation (biology)
References
Evolutionary biology | Megaevolution | [
"Biology"
] | 622 | [
"Evolutionary biology"
] |
44,241,796 | https://en.wikipedia.org/wiki/Yanosuke%20Hirai | was a Japanese civil engineer and corporate executive in the electric power industry. He developed electric power generation in the Tohoku region during the Shōwa era with unusual foresight and a deep sense of responsibility.
25 years after his death, Hirai’s foresight protected lives and environment from the March 11, 2011 Tohoku earthquake and tsunami. The Onagawa Nuclear Power Plant (Miyagi Prefecture), designed and built under his watch, was the sole plant in the region that fully resisted the disaster of March 11, 2011: all of its three reactors successfully withstood the seismic event and subsequent tsunami, shutting down safely as designed and virtually without any incident. The site of the plant even ended up providing a refuge for three months to more than 300 neighboring people who had lost their homes.
Main achievements – Risk management for earthquakes and tsunamis
As the following two examples show, Yanosuke Hirai, based on his convictions as an engineer and his sense of responsibility as a member of the electric power industry, insisted on the importance of taking highly precautionary protective measures against earthquakes and tsunamis. Born in the Miyagi Prefecture, Hirai was keenly aware of how dreadful earthquakes and tsunamis could be; he is said to have often made reference to the great Jogan tsunami of the year 869, which had reportedly travelled 7 kilometers inland from the coast, and had even reached the Sengan Shinto shrine in Iwanuma, his birth town.
During the construction of a thermal power station in Niigata in 1957, he considered the risk of soil liquefaction being caused by an earthquake and ordered a 12 meters deep caisson (a reinforced concrete box, or so-called raft foundation) on which the thermal station was erected .In 1964, the Niigata earthquake in fact caused soil liquefaction of 10 meters deep, vindicating the usefulness of Hirai’s ‘mammoth’ caisson which, at the time of construction, had seemed excessive for some experts. Just after the earthquake, when a TV reported, with an image of a building on fire, that the Niigata thermal power station had exploded, Y. Matsunaga, the so-called “King of Electric Power of Japan” immediately retorted: “That’s a mistake. The power station Hirai constructed cannot be broken.” In fact, it was a case of misreporting and there was no damage; the main body of the power station only sank 20 centimeters just perpendicularly.
In 1968, Tohoku Electric Power established a committee to prepare the construction plan of the Onagawa nuclear power plant (NPP). As a member of the committee, Hirai was the only one to insist, after examination of past tsunami records, that the plant be built 14.8 m above the sea level. Although the height proposed by Hirai was five times as much as the then generally assumed expected height of a tsunami at Onagawa, the Tohoku Electric Power management consented to his proposal. Moreover, he devised a safety measure for a tsunami’s withdrawal: an inlet channel and a reservoir containing enough seawater for cooling the nuclear reactors during 40 minutes. The construction of the three nuclear reactors of the Onagawa NPP was completed in 2002. On March 11, 2011, the Onagawa NPP was hit by the Tohoku earthquake and tsunami (magnitude 9.0). In contrast to the Fukushima Daiichi NPP, which experienced a meltdown of three of the plant’s six nuclear reactors, all three reactors of the Onagawa NPP which was closer to the epicenter of the earthquake and endured stronger quake and same tsunami level — survived virtually intact. Waves of 13.78 m high (12.78 m of wave height and 1 m of land subsidence) attacked the NPP, but did not reach it by 1 m.An IAEA mission to Onagawa NPP presented a 92-page report to the government of Japan, after collecting earthquake experience data from 30 July to 11 August 2012 at Onagawa. The report concludes as follows:
“Despite prolonged ground shaking and a significant level of seismic energy input to [its] facilities, the structures, systems and components of the Onagawa nuclear power station performed their intended functions without any significant damage. The lack of any serious damage to all classes of seismically designed facilities attests to the robustness of these facilities under severe seismic ground shaking.”
Personality
One of Hirai’s former staff members testifies as follows. “Hirai was a man with a strict sense of responsibility. He was strongly convinced that an engineer must take responsibility for the whole chain of consequences of his decisions, and that mere compliance with the letter of the law or regulations would not provide him a reasonable excuse.”
The origin of Hirai’s deep, uncompromising sense of responsibility as a power engineer may be found in the conviction he shared with of Y. Matsunaga, the above-mentioned “King of Electric Power of Japan”, who maintained that, because electric power was the foundation of social life and industry, its safe production at the lowest cost and without any discontinuity was ‘their’ duty.
Hirai also had an uncanny capacity to convince others to adopt his point of view by clearly articulating and backing up the arguments for it. This was shown by his success, both in the Niigata and Onagawa cases, in securing collective decisions in favor of a much higher level of precaution than other experts would have advocated. In the groupthink atmosphere that prevails in many large enterprises in Japan, this was no mean feat.
Career
1902 Born in Shibata, Miyagi Prefecture, Japan.
1926 Graduates in Civil Engineering at the Faculty of Engineering of Tokyo Imperial University (now the University of Tokyo) after completing Daini Senior High School (old system) in Sendai.
1926 Joins Toho Electric Power Company, Director at the Construction Site of Kawabe Hydroelectric Power Plant (Hida River), Works under the guidance of Yasuzaemon Matsunaga .
1941 Joins Japan Electric Generation and Transmission Company (Nihon Hassōden) (jp:日本発送電), Director at the Construction Site of the Kurobe Hydroelectric Power Plant (Oku-nikko).
1945 Successively Head of the Civil Engineering Section, Manager of Civil Engineering Department and Member of the board of directors at the Headquarters of Nihon Hassōden, takes a leading part in the postwar reconstruction of electric power generation of Japan.
1951 Serves simultaneously as Director of Construction Bureau, Manager of the Department of Civil Engineering and Member of the board of directors of Tohoku Electric Power Company. Under company president Jiro Shirasu, dedicates himself to the development of electric power plants in the Tohoku district, being in charge of the Tadami River hydroelectric project and introduction of large-scale thermal power stations. Commissioned by the Electric Power Development Company (J-POWER), works as Director in the construction project of the largest hydroelectric power plant in Japan, the Tagokura Dam.
1960 Vice-president of Tohoku Electric Power Company.
1963 Member of the board of directors, subsequently Vice President, at the Central Research Institute of Electric Power Industry (CRIEPI) and Director of its Laboratory of Technology.
1968 Member of the Coast Facility Planning Committee, Tohoku Electric Power Company.
1975 Retires from CRIEPI, becoming Adviser.
1986 Dies at the age of 83.
Awards
1961 Medals of Honor (Japan) with Blue Ribbon (藍綬褒章).
1972 3rd Class, Gold Rays with Neck Ribbon, Order of the Rising Sun（勲三等旭日中綬章）
1986 Jushii (Junior Fourth Rank 従四位)
Notes
References
Tatsuji Ōshima (大島達治), Gijutsu Hōdan (技術放談) (Random talks over the technology), Sendai, 2013, pp. 60–62.
1902 births
1986 deaths
Earthquake engineering
Tsunami
University of Tokyo alumni
People from Miyagi Prefecture
Japanese civil engineers | Yanosuke Hirai | [
"Engineering"
] | 1,648 | [
"Earthquake engineering",
"Civil engineering",
"Structural engineering"
] |
55,851,068 | https://en.wikipedia.org/wiki/Not-all-equal%203-satisfiability | In computational complexity, not-all-equal 3-satisfiability (NAE3SAT) is an NP-complete variant of the Boolean satisfiability problem, often used in proofs of NP-completeness.
Definition
Like 3-satisfiability, an instance of the problem consists of a collection of Boolean variables and a collection of clauses, each of which combines three variables or negations of variables. However, unlike 3-satisfiability, which requires each clause to have at least one true Boolean value, NAE3SAT requires that the three values in each clause are not all equal to each other (in other words, at least one is true, and at least one is false).
Hardness
The NP-completeness of NAE3SAT can be proven by a reduction from 3-satisfiability (3SAT). First the nonsymmetric 3SAT is reduced to the symmetric NAE4SAT by adding a common dummy literal to every clause, then NAE4SAT is reduced to NAE3SAT by splitting clauses as in the reduction of general -satisfiability to 3SAT.
In more detail, a 3SAT instance (where the are arbitrary literals) is reduced to the NAE4SAT instance where is a new variable. A satisfying assignment for becomes a satisfying assignment for by setting . Conversely a satisfying assignment with for must have at least one other literal true in each clause and thus be a satisfying assignment for . Finally a satisfying assignment with for can because of symmetry of and be flipped to produce a satisfying assignment with .
NAE3SAT remains NP-complete when all clauses are monotone (meaning that variables are never negated), by Schaefer's dichotomy theorem.
Monotone NAE3SAT can also be interpreted as an instance of the set splitting problem, or as a generalization
of graph bipartiteness testing to 3-uniform hypergraphs: it asks whether the vertices of a hypergraph can be colored with two colors so that no hyperedge is monochromatic. More strongly, it is NP-hard to find colorings of 3-uniform hypergraphs with any constant number of colors, even when a 2-coloring exists.
Easy cases
Unlike 3SAT, some variants of NAE3SAT in which graphs representing the structure of variables and clauses are planar graphs can be solved in polynomial time. In particular this is true when there exists a planar graph with one vertex per variable, one vertex per clause, an edge for each variable–clause incidence, and a cycle of edges connecting all the variable vertices.
References
NP-complete problems
Satisfiability problems | Not-all-equal 3-satisfiability | [
"Mathematics"
] | 547 | [
"Automated theorem proving",
"Computational problems",
"Mathematical problems",
"NP-complete problems",
"Satisfiability problems"
] |
55,851,179 | https://en.wikipedia.org/wiki/Ridge%20and%20swale | Ridge and swale, or in dunal areas dune and swale, is a landform consisting of regular, parallel ridges alternating with marshy depressions. Ridge-and-swale landscapes are most commonly formed by the gradual movement of a beach, for example as a result of gradually fluctuating water levels, or the shifting meanders of a river. In the river context, ridge-and-swale landscapes are commonly formed by scroll bars. They are also found along ocean coasts, for example on the Outer Banks of North Carolina.
Great Lakes ridge and swale
Freshwater ridge-and-swale ecosystems are globally rare and found only in parts of the Great Lakes of North America. They were formed as a result of the gradual retreat of beaches due to falling water levels and post-glacial rebound. The swales and the adjoining lake or river commonly form a single hydrological unit, so that rising or falling lake levels will cause water levels in the swales to rise or fall as well. Most ridge-and-swale landscapes have been destroyed as a result of the massive industrial development found in many former ridge-and-swale areas, such as the Calumet Region of Northwest Indiana. However, some extensive dune-and-swale complexes persist in Michigan, such as at the Michigan Wilderness State Park. The remaining dune-and-swale complexes along the Great Lakes are often home to extremely rare plants and animals, such as the endangered Karner Blue butterfly.
In the Calumet Region, the difficulty of moving equipment through dune-and-swale topography greatly slowed industrial development, but could not stop it after the turn of the 20th century. The few remnants are preserved as nature preserves, including the Gibson Woods county park in Hessville, Indiana, the Miller Woods section of the Indiana Dunes National Park, and additional preserves operated by The Nature Conservancy and Shirley Heinze Land Trust.
Works cited
References
External links
Wooded dune and swale complex
Landforms
Wetlands | Ridge and swale | [
"Environmental_science"
] | 404 | [
"Hydrology",
"Wetlands"
] |
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