id int64 39 79M | url stringlengths 31 227 | text stringlengths 6 334k | source stringlengths 1 150 ⌀ | categories listlengths 1 6 | token_count int64 3 71.8k | subcategories listlengths 0 30 |
|---|---|---|---|---|---|---|
12,063,277 | https://en.wikipedia.org/wiki/Methoxy%20arachidonyl%20fluorophosphonate | Methoxy arachidonyl fluorophosphonate, commonly referred as MAFP, is an irreversible active site-directed enzyme inhibitor that inhibits nearly all serine hydrolases and serine proteases. It inhibits phospholipase A2 and fatty acid amide hydrolase with special potency, displaying IC50 values in the low-nanomolar range. In addition, it binds to the CB1 receptor in rat brain membrane preparations (IC50 = 20 nM), but does not appear to agonize or antagonize the receptor, though some related derivatives do show cannabinoid-like properties.
See also
DIFP – diisopropyl fluorophosphate, a related inhibitor
IDFP – isopropyl dodecylfluorophosphonate, another related inhibitor with selectivity for FAAH and MAGL
Activity-based probes
References
Cannabinoids
Phosphonofluoridates
Serine protease inhibitors
Arachidonyl compounds | Methoxy arachidonyl fluorophosphonate | [
"Chemistry",
"Biology"
] | 215 | [
"Biotechnology stubs",
"Functional groups",
"Biochemistry stubs",
"Phosphonofluoridates",
"Biochemistry"
] |
12,064,016 | https://en.wikipedia.org/wiki/Adams%20hemisphere-in-a-square%20projection | The Adams hemisphere-in-a-square is a conformal map projection for a hemisphere. It is a transverse version of the Peirce quincuncial projection, and is named after American cartographer Oscar S. Adams, who published it in 1925. When it is used to represent the entire sphere it is known as the Adams doubly periodic projection. Like many conformal projections, conformality fails at certain points, in this case at the four corners.
See also
List of map projections
Guyou hemisphere-in-a-square projection
Doubly periodic function
References
Conformal projections | Adams hemisphere-in-a-square projection | [
"Mathematics"
] | 121 | [
"Geometry",
"Geometry stubs"
] |
12,065,768 | https://en.wikipedia.org/wiki/Fire%20retardant%20gel | Fire-retardant gels are superabsorbent polymer slurries with a "consistency almost like petroleum jelly."
Fire-retardant gels can also be slurries that are composed of a combination of water, starch, and clay.
Used as fire retardants, they can be used for structure protection and in direct-attack applications against wildfires.
Fire-retardant gels are short-term fire suppressants typically applied with ground equipment.
They are also used in the movie industry to protect stunt persons from flames when filming action movie scenes.
History
The practical use of gels was limited until the 1950s as advances in copolymerization techniques led to reproducible, batchwise preparation of swellable resins with uniform cross-linking. This technology was later used in the development of a "substantially continuous, adherent, particulate coating composition of water-swollen, gelled particles of a crosslinked, water-insoluble, water-swellable polymer."
The water-absorbent polymers in fire-retardant gels are similar to those used in diapers.
Mechanism of retardation
The polymer in gels soaks up hundreds of times its weight in water creating millions of tiny drops of water surrounded by and protected by a polymer shell. The result is a "bubblet" or a drop of water surrounded by a polymer shell in contrast to a bubble which is air surrounded by liquid. As the gel and water are sprayed onto an exposed surface, millions of tiny "bubblets" are stacked one on top of another. The stacking of the water "bubblets" form a thermal protective "blanket" over the surface to which it is applied. In order for the heat of the fire to penetrate the protected surface, it must burn off each layer of the gel "bubblets" coating. Each layer holds the heat away from the next layer of bubblets beneath. The polymer shell of each bubblets and their stacking significantly prevent water evaporation.
The stacking of the bubblets is similar to aspirated fire fighting foam or compressed air foam systems, except that bubblets are water filled, whereas foam bubbles are only filled with air. Due to the high specific heat of water, it requires more energy to raise the temperature of water than air. Therefore, water-filled bubblets will absorb more heat than the air-filled foam bubbles (which are more effective for vapor suppression). When gel is applied to a surface such as an exterior wall, the water-filled bubblets can absorb much of the heat given off by the fire, thereby slowing the fire from reaching the wall.
Gels can provide thermal protection from fire for extended periods even at . Depending on the fire conditions, applied fire retardant gels offer fire protection for periods of 6 to 36 hours.
After the retained water is completely evaporated from a gel, fire resistance is lost, but can be restored by re-wetting the surface if gel material is still adherent.
Uses
Fire retardant gels create a fire protective gel coating that completely repels flaming embers and is extremely effective in cases of emergency in protecting structures from the flame fronts typical of most wildfires.
During a fire in the Black Hills National Forest, "nearly all homes coated with a slimy gel were saved while dozens of houses nearby burned to the ground."
Certain supplemental fire protection insurance may include the application of fire-retardant gel to homes during wildfire. Claimed to work "best when applied hours before a fire approaches", gel is applied using specially designed trucks by private firms. However, danger may be high and private firms may interfere with fire efforts. In response to such a concern, Sam DiGiovanna, chief of Firebreak response program, a private response team, stated: "If whoever is running the fire thinks it's too dangerous to go into a particular area, we don't go into that area."
These gels are useful when filming scenes in which it is desired to give the illusion that someone is on fire. To do so, the gel is applied to an area of the body. Next, a fuel is placed on top of the gel. When ready to film the scene, the fuel is lit on fire. The gel insulates the person from the energy released from the burning fuel. The energy from the burning fuel goes into the gel, but not the stunt person. Thus, the stunt person is protected from being burned.
References
James H. Meidl: "Flammable Hazardous Materials", Glencoe Press Fire Science Series, 1970.
External links
Fire suppression
Fire suppression agents
Wildfire suppression
Fire protection | Fire retardant gel | [
"Engineering"
] | 955 | [
"Building engineering",
"Fire protection"
] |
12,066,155 | https://en.wikipedia.org/wiki/International%20Conference%20on%20Computer%20and%20Information%20Technology | International Conference on Computer and Information Technology or ICCIT is a series of computer science and information technology based conferences that is hosted in Bangladesh since 1997 by a different university each year. ICCIT provides a forum for researchers, scientists, and professionals from both academia and industry to exchange up-to-date knowledge and experience in different fields of computer science/engineering and information and communication technology (ICT). This is a regularly held ICT based major annual conference (held typically in December) in Bangladesh now in its 25th year. ICCIT series has succeeded in engaging the most number of universities in Bangladesh from both public and private sectors. Each new university in Bangladesh have been investing in computer science, computer engineering, information systems, and related fields.
Starting 2008, the ICCIT is co-sponsored by IEEE. On average, since 2003, 31.1% manuscripts submitted are accepted for presentation and inclusion in the IEEE Xplore Digital Library, one of the largest scholarly research database containing over two million records that indexes, abstracts, and provides full-text for articles and papers on computer science, electrical engineering, electronics, information technology, and physical sciences.
History
ICCIT trace its history to 1997 when University of Dhaka organized a conference, National Conference on Computer and Information Systems (NCCIS) based on IT and Computer Science. Probably it was the first initiative to organize an IT based conference in Bangladesh with participation from multiple universities. Very next year in 1998, this conference was renamed to its current name and gained international status by opening its door to the participants from outside of Bangladesh. Since then each year a university approved by the ICCIT committee hosts this event during late December.
Areas
ICCIT is mainly focused on computer science and information technology but also covers related electronic engineering topics. Major areas of ICCIT include, but not limited to:
Algorithms
Artificial intelligence
Bengali language processing
Bio-informatics
Computer vision
Computer graphics and multimedia
Computer network and data communications
Computer based education
Database systems
Digital signal processing and image processing
Digital system and logic design
Distributed and parallel processing
E-commerce and E-governance
Human computer interaction
Information systems
Internet and World Wide Web Applications
Knowledge data engineering
Neural networks
Pattern recognition
Robotics
Software engineering
System security
Ubiquitous computing
VLSI
Wireless communications and mobile computing
Past conferences
Starting 1997, ICCIT has had 24 successful events at 20 different universities.
1997 University of Dhaka, Dhaka (as NCCIS '97)
1998 Bangladesh University of Engineering and Technology (BUET), Dhaka
1999 Shahjalal University of Science and Technology, Sylhet
2000 North South University, Dhaka
2001 University of Dhaka, Dhaka
2002 East West University, Dhaka
2003 Jahangirnagar University, Savar
2004 BRAC University, Dhaka
2005 Islamic University of Technology (IUT), Gazipur
2006 Independent University Bangladesh (IUB), Dhaka
2007 United International University (UIU), Dhaka
2008 Khulna University of Engineering and Technology (KUET), Khulna
2009 Independent University Bangladesh (IUB) and Military Institute of Science and Technology, Dhaka
2010 Ahsanullah University of Science and Technology, Dhaka
2011 American International University-Bangladesh, Dhaka
2012 Chittagong University, Chittagong
2013 Khulna University, Khulna
2014 Daffodil International University, Dhaka
2015 Military Institute of Science and Technology, Dhaka
2016 North South University, Dhaka
2017 University of Asia Pacific, Dhaka
2018 United International University, Dhaka
2019 Southeast University, Dhaka
2020 Ahsanullah University of Science and Technology, Dhaka
2021 North South University, Dhaka
International Program Committee
The key to the success of ICCIT is its International Program Committee (IPC), co-chaired by Professor Mohammad Ataul Karim, of University of Massachusetts Dartmouth and Professor Mohammad Showkat Alam of Texas A&M University-Kingsville. The IPC for ICCIT 2012, for example, is a body of eighty five (85) field experts all of whom are affiliated with either a university or a research organisation from outside of Bangladesh. The national make-up of the latest IPC is as follows: USA (43), Australia (12), Canada(6), UK (5), Malaysia (4), Japan (3), Germany (2), India (2), Korea (2), New Zealand (2), Belgium (1), China (1), Ireland (1), Norway (1), and Switzerland (1).
Journal special issues
Starting with ICCIT 2008, a selected number of manuscripts after further enhancement and extensive review process are being included in one of several journal special issues. ICCIT doesn't end with just conference proceedings but with those that are indexed worldwide and takes many of its better papers to its next logical level to the journals. To date, 14 journal special issues have been produced by ICCIT IPC featuring works of Bangladesh-based researchers in the fields of communications, computing, multimedia, networks, and software. This is a serious feat for Bangladesh its many researchers; the outcome from this single conference is allowing for about 30–35 team of researchers each year to be able to showcase their research through archival and indexed journals that really matter. It is a major scholarly milestone which makes ICCIT series different from all other technical conferences held in Bangladesh. In its latest iteration, 32 selected enhanced ICCIT 2011 manuscripts after having gone through extensive reviews have been accepted now for inclusion in the following international journals.
Journal of Communications
Guest Editors: M.N. Islam, SUNY Farmingdale, US; K.M. Iftekharuddin, Old Dominion University, US; M.A. Karim, Old Dominion University, US; M.A. Salam, Southern University & A&M College, Louisiana, US
Journal of Computers
Guest Editors: S.M. Aziz, University of South Australia, Australia; M.S. Alam, University of South Alabama, US; K.V. Asari, University of Dayton, US; M. Alamgir Hossain, University of Northumbria, UK; M.A. Karim, Old Dominion University, US; M. Milanova, University of Arkansas at Little Rock, US
Journal of Multimedia
Guest Editors: M. Murshed, Monash University, Australia; M.A. Karim, Old Dominion University, US; M. Paul, Monash University, Australia; S. Zhang, College of Staten Island, US
Journal of Networks
Guest Editors: S. Jabir, France Telecom, Japan; J. Abawajy, Deakin University, Australia; F. Ahmed, Johns Hopkins University Applied Physics Laboratory, US; M.A. Karim, Old Dominion University, US; J. Kamruzzaman, Monash University, Australia; Nurul I. Sarkar, Auckland University of Technology, New Zealand
References
External links
11th ICCIT Home page
15th ICCIT Home page
Computer science conferences
Information technology in Bangladesh | International Conference on Computer and Information Technology | [
"Technology"
] | 1,383 | [
"Computer science",
"Computer science conferences"
] |
12,066,349 | https://en.wikipedia.org/wiki/MAASP | Maximum Allowable Annulus Surface Pressure is an absolute upper limit for the pressure in the annulus of an oil and gas well as measured at the wellhead.
Background
Preserving well integrity is a vital task for the operators. This includes ensuring that the annuli remain intact. One major threat to annulus integrity is overpressure within the annulus, which could lead to burst or collapse of a casing or damage to the formation below. This will happen first at the shoe of the annulus because the pressure will naturally be higher with the weight of the column of brine. However, annuli usually only have pressure gauges at the wellhead. Therefore, a MAASP is calculated to provide a surface pressure, which will produce the limiting pressure at the shoe.
Determining a MAASP
There are four different ways an annulus may be overpressured: burst of the outside casing, collapse of the inside casing, fracturing of the formation at the shoe, overpressure of the surface equipment. Each of these produces its own limiting pressure at the shoe. The MAASP is taken as the most limiting of these.
The following example is for the 'B' annulus of a gas lifted well, filled with 1.2 sg brine from the shoe at 4070ftTVD (true vertical depth) to surface.
Burst of outside casing
In this well, the outside casing of the 'B' annulus is N80 grade with a weight of −1. The burst pressure of this casing is 5020 psi. 1.2 sg brine produces a pressure gradient of 0.52 psi.ft−1 (see Well kill for the mathematical basics of hydrostatic heads). Therefore, the column of brine produces a pressure difference between top and bottom of 2116 psi. Therefore, the pressure at the wellhead can reach 2904 psi before 5020 psi is reached at the bottom. Therefore, the MAASP for casing burst is 2904 psi.
Collapse of inside casing
The inside casing is L80 −1. The collapse pressure of this casing is 4750 psi. Therefore, pressure at the shoe of the 'B' annulus cannot exceed this. Given a hydrostatic head of 2116 psi, the pressure at the wellhead must not exceed 2634 psi.
Fracturing the formation
Geologists will have logged fracture pressures of the formation as the well was drilled. This can be used to provide a limiting pressure much as before. If the cement used to cement the casing in place is still intact, fracturing the formation is not a hazard.
Surface equipment
Wellheads usually have a pressure rating of 5000 psi, 10,000 psi or 15,000 psi. These are far in excess of the other limits.
Published MAASP
Collapse of the casing is clearly the limiting factor so the MAASP will be published as 2634 psi.
See also
Well integrity
Annulus (oil well)
Oil wells | MAASP | [
"Chemistry"
] | 603 | [
"Petroleum technology",
"Oil wells"
] |
12,066,363 | https://en.wikipedia.org/wiki/Bergen%20Academy%20of%20Art%20and%20Design | Bergen Academy of Art and Design () or KHiB was one of two independent and accredited scientific institutions of higher learning in the visual arts and design in Norway (The other is Oslo National Academy of the Arts). It was located in Bergen, Norway. The education included the subject areas fine art, photography, printmaking, ceramics, textiles, visual communication, interior architecture and furniture design. The college had around 350 students.
KHiB is now merged with The Grieg Academy - Department of Music, and together they make up the Faculty of Fine Art, Music and Design, as one of seven faculties at University of Bergen (UiB). The faculty was formally established on 1 January 2017, and has three departments: The Art Academy - Department of Art, The Grieg Academy - Department of Music and Department of Design.
History
Art education has long traditions in Bergen, as the first school of art was established there in 1772, modelled on the Academy of Art in Copenhagen. Bergen Academy of Art and Design was itself a young institution established in 1996, merged from two former institutions; Vestlandets kunstakademi which had been founded in 1972 and Statens høgskole for kunsthåndverk og design which is dated to 1909.
The academy had facilities in six different buildings in Bergen centre; in Strømgaten 1, Marken 37, Vaskerelven 8, Kong Oscars gate 62 and C. Sundts. gate 53 and 55. Strømgaten 1, which previously housed Bergen Technical School, was protected by regulations on 25 June 2013. The building was designed by Giovanni Müller and built in the years 1874-76. In 2017, all facilities were co-located in Møllendalsveien in a new purpose-built building designed by Snøhetta.
References
External links
Official site
Art schools in Norway
Industrial design
Educational institutions established in 1996
Graphic design schools
Universities and colleges in Norway
Education in Bergen
1996 establishments in Norway | Bergen Academy of Art and Design | [
"Engineering"
] | 405 | [
"Industrial design",
"Design engineering",
"Design"
] |
12,066,647 | https://en.wikipedia.org/wiki/Motherboard%20form%20factor | In computing, the motherboard form factor is the specification of a motherboard – the dimensions, power supply type, location of mounting holes, number of ports on the back panel, etc. Specifically, in the IBM PC compatible industry, standard form factors ensure that parts are interchangeable across competing vendors and generations of technology, while in enterprise computing, form factors ensure that server modules fit into existing rackmount systems. Traditionally, the most significant specification is for that of the motherboard, which generally dictates the overall size of the case. Small form factors have been developed and implemented.
Overview of form factors
A PC motherboard is the main circuit board within a typical desktop computer, laptop or server. Its main functions are as follows:
To serve as a central backbone to which all other modular parts such as CPU, RAM, and hard drives can be attached as required to create a computer
To be interchangeable (in most cases) with different components (in particular CPU and expansion cards) for the purposes of customization and upgrading
To distribute power to other circuit boards
To electronically co-ordinate and interface the operation of the components
As new generations of components have been developed, the standards of motherboards have changed too. For example, the introduction of AGP and, more recently, PCI Express have influenced motherboard design. However, the standardized size and layout of motherboards have changed much more slowly and are controlled by their own standards. The list of components required on a motherboard changes far more slowly than the components themselves. For example, north bridge microchips have changed many times since their introduction with many manufacturers bringing out their own versions, but in terms of form factor standards, provisions for north bridges have remained fairly static for many years.
Although it is a slower process, form factors do evolve regularly in response to changing demands. IBM's long-standing standard, AT (Advanced Technology), was superseded in 1995 by the current industry standard ATX (Advanced Technology Extended), which still governs the size and design of the motherboard in most modern PCs. The latest update to the ATX standard was released in 2007. A divergent standard by chipset manufacturer VIA called EPIA (also known as ITX, and not to be confused with EPIC) is based upon smaller form factors and its own standards.
Differences between form factors are most apparent in terms of their intended market sector, and involve variations in size, design compromises and typical features. Most modern computers have very similar requirements, so form factor differences tend to be based upon subsets and supersets of these. For example, a desktop computer may require more sockets for maximum flexibility and many optional connectors and other features on board, whereas a computer to be used in a multimedia system may need to be optimized for heat and size, with additional plug-in cards being less common. The smallest motherboards may sacrifice CPU flexibility in favor of a fixed manufacturer's choice. The E-ATX form factor is not standarized and may vary according to the motherboard manufacturer.
Comparisons
Tabular information
Size variants
List is incomplete
Maximum number of expansion card slots
ATX case compatible:
Visual examples of different form factors
PC/104 and EBX
PC/104 is an embedded computer standard which defines both a form factor and computer bus. PC/104 is intended for embedded computing environments. Single-board computers built to this form factor are often sold by COTS vendors, which benefits users who want a customized rugged system, without months of design and paper work.
The PC/104 form factor was standardized by the PC/104 Consortium in 1992. An IEEE standard corresponding to PC/104 was drafted as IEEE P996.1, but never ratified.
The 5.75 × 8.0 in Embedded Board eXpandable (EBX) specification, which was derived from Ampro's proprietary Little Board form-factor, resulted from a collaboration between Ampro and Motorola Computer Group.
As compared with PC/104 modules, these larger (but still reasonably embeddable) SBCs tend to have everything of a full PC on them, including application oriented interfaces like audio, analog, or digital I/O in many cases. Also it's much easier to fit Pentium CPUs, whereas it's a tight squeeze (or expensive) to do so on a PC/104 SBC. Typically, EBX SBCs contain: the CPU; upgradeable RAM subassemblies (e.g., DIMM); Flash memory for solid state drive; multiple USB, serial, and parallel ports; onboard expansion via a PC/104 module stack; off-board expansion via ISA and/or PCI buses (from the PC/104 connectors); networking interface (typically Ethernet); and video (typically CRT, LCD, and TV).
Mini PC
Mini PC is a PC small form factor very close in size to an external CD or DVD drive. Mini PCs have proven popular for use as HTPCs.
Examples
AOpen XC mini
Apple Mac mini
Intel NUC
Gigabyte Brix
Zotac ZBOX
Asus Vivopc
Lenovo ThinkCentre Tiny
Dell Optiplex Mini/Micro
Acer Veriton
See also
Hard-disk-drive form factors
Small form factor
PICOe
Notes
References
External links
Form Factors: Micro ATX vs. Mini ITX vs. ATX
The official Intel Form factors website containing form factor descriptions
Micro ATX vs Mini ITX vs ATX
Computing comparisons | Motherboard form factor | [
"Technology"
] | 1,118 | [
"Computing comparisons"
] |
12,066,660 | https://en.wikipedia.org/wiki/List%20of%20steroid%20abbreviations | The steroid hormones are referred to by various abbreviations in the biological literature. The purpose of this list is to give commonly used abbreviations for steroid hormones, with supporting references to the literature.
Table of abbreviations
References
Steroids
Steroid abbreviations | List of steroid abbreviations | [
"Chemistry"
] | 53 | [
"nan"
] |
12,066,797 | https://en.wikipedia.org/wiki/Gromov%27s%20systolic%20inequality%20for%20essential%20manifolds | In the mathematical field of Riemannian geometry, M. Gromov's systolic inequality bounds the length of the shortest non-contractible loop on a Riemannian manifold in terms of the volume of the manifold. Gromov's systolic inequality was proved in 1983; it can be viewed as a generalisation, albeit non-optimal, of Loewner's torus inequality and Pu's inequality for the real projective plane.
Technically, let M be an essential Riemannian manifold of dimension n; denote by sysπ1(M) the homotopy 1-systole of M, that is, the least length of a non-contractible loop on M. Then Gromov's inequality takes the form
where Cn is a universal constant only depending on the dimension of M.
Essential manifolds
A closed manifold is called essential if its fundamental class defines a nonzero element in the homology of its fundamental group, or more precisely in the homology of the corresponding Eilenberg–MacLane space. Here the fundamental class is taken in homology with integer coefficients if the manifold is orientable, and in coefficients modulo 2, otherwise.
Examples of essential manifolds include aspherical manifolds, real projective spaces, and lens spaces.
Proofs of Gromov's inequality
Gromov's original 1983 proof is about 35 pages long. It relies on a number of techniques and inequalities of global Riemannian geometry. The starting point of the proof is the imbedding of X into the Banach space of Borel functions on X, equipped with the sup norm. The imbedding is defined by mapping a point p of X, to the real function on X given by the distance from the point p. The proof utilizes the coarea inequality, the isoperimetric inequality, the cone inequality, and the deformation theorem of Herbert Federer.
Filling invariants and recent work
One of the key ideas of the proof is the introduction of filling invariants, namely the filling radius and the filling volume of X. Namely, Gromov proved a sharp inequality relating the systole and the filling radius,
valid for all essential manifolds X; as well as an inequality
valid for all closed manifolds X.
It was shown by that the filling invariants, unlike the systolic invariants, are independent of the topology of the manifold in a suitable sense.
and developed approaches to the proof of Gromov's systolic inequality for essential manifolds.
Inequalities for surfaces and polyhedra
Stronger results are available for surfaces, where the asymptotics when the genus tends to infinity are by now well understood, see systoles of surfaces. A uniform inequality for arbitrary 2-complexes with non-free fundamental groups is available, whose proof relies on the Grushko decomposition theorem.
Notes
See also
Filling area conjecture
Gromov's inequality (disambiguation)
Gromov's inequality for complex projective space
Loewner's torus inequality
Pu's inequality
Systolic geometry
References
.
Geometric inequalities
Riemannian geometry
Systolic geometry
Theorems in Riemannian geometry | Gromov's systolic inequality for essential manifolds | [
"Mathematics"
] | 660 | [
"Geometric inequalities",
"Inequalities (mathematics)",
"Theorems in geometry"
] |
12,067,406 | https://en.wikipedia.org/wiki/Anti-set-off%20spray%20powder | In printing, anti-set-off spray powder is used to make an air gap between printed sheets of paper. This enables the ink to dry naturally and therefore avoid the unwanted transfer of ink from one printed sheet to another. The problem can occur with most types of printing.
Anti-set-off spray powder is generally made from natural starches from plants and vegetables. There remains a demand for soluble powders (sometimes known as vanished powders) based on natural sugars which are often used when the final printed sheet is to be varnished. In addition there is still a relatively small amount of powder made from minerals (e.g. Calcium Carbonate, rather than Talc) used in offset litho printing; however these mineral powders are not so popular because of the potential health implications and abrasive properties.
Spray powder is used to separate printed sheets to enable air to naturally dry the printing ink. The diameter of the powder used is relative to the density (g/m2) of the stock (paper or board) being printed. For 150 g/m2 paper the ideal anti-set-off spray powder would be 15 μm in diameter, for 200 g/m2 20 μm, through to 70 μm for heavy board (700 g/m2).
Most manufactures of spray powder offer both coated and uncoated powders. Uncoated powders are generally less expensive and are based on natural food-grade starches typically derived from corn (maize), wheat, semolina, potato, tapioca and rice depending on the diameter required. Coated powders use the same range of raw materials but are encapsulated with a minuscule amount of natural coatings which enable the powders to flow freely though the spray guns on sheet-fed offset-litho printing presses. Enhanced versions of these coatings are used to give specific electrostatic (anti-static) and hydrophobic properties.
Spray powder is not used on rotary presses including rotary letterpress, web offset (often used for printing magazines), flexographic (often used for printing flexible packaging and labels) or gravure (often used for printing long-run catalogues). Similarly, spray powder is not generally used in sheet-fed (silk) screen-printing, ink-jet or toner based digital printing.
In the UK, many Carrom players use a version of anti-set-off spray powder from the printing industry which has specific electrostatic properties with particles of 50 micrometres in diameter.
Modern developments
As health and safety has become more important to the environment and to the work forces, a small number of anti-set-off spray powder manufacturers had introduced highly clarified powders by 2007, in advance of EU legislation. This new generation of powders have typically less than 3% of particles of less than 10 μm and almost no particles below 5 μm which are generally regarded in the industry as dust. To put this in context typical human hair is 20 – 40 μm.
The printing industry regards anti-set-off spray powder as a necessary evil. Ideally printers would prefer not to use it, but it remains the only practical way to ensure a stack of printed paper at the end of a printing press does not set-off. In recent years there has been an emergence of printing presses which use inks that are cured (dried) with powerful UV lamps. As each sheet is individually dried there is no need for spray powder. However, as these machines require specialty inks which are much more expensive than conventional inks, and the UV lamps use a significant amount of energy, the vast majority of new sheet-fed presses sold in 2007 still used anti-set-off spray powder.
Other uses
In addition to its use in the printing and packaging industry, spray powder is also used in the manufacture of float glass to enable the large sheets to slide easily over each other. It is also used in the manufacture of plastic food wrap and similar products to help prevent pieces of plastic from sticking together because of static electricity.
In the UK, many carrom players use a version of anti-set-off spray powder from the printing industry which has specific electrostatic properties with particles of 50 micrometres in diameter.
See also
lithography
Set-off (printing)
See also Printing
External links
Learn about printing — International Paper
Glossary of printing terms — International Paper
References
Printing materials
Powders | Anti-set-off spray powder | [
"Physics"
] | 892 | [
"Printing materials",
"Materials",
"Powders",
"Matter"
] |
12,067,755 | https://en.wikipedia.org/wiki/List%20of%20the%20brightest%20Kuiper%20belt%20objects | Since the year 2000, a number of Kuiper belt objects (KBOs) with diameters of between 500 and 1500 km (more than half that of Pluto) have been discovered. 50000 Quaoar, a classical KBO discovered in 2002, is over 1000 km across. and , both announced on 29 July 2005, are larger still. Other objects, such as 28978 Ixion (discovered in 2001) and 20000 Varuna (discovered in 2000) measure roughly 500 km across. This has led gradually to the acceptance of Pluto as the largest member of the Kuiper belt.
The brightest known dwarf planets and other KBOs (with absolute magnitudes < 4.0) are:
See also
List of trans-Neptunian objects
References
List of the brightest KBOs
Lists of trans-Neptunian objects
Kuiper belt objects, brightest | List of the brightest Kuiper belt objects | [
"Astronomy"
] | 179 | [
"Astronomy-related lists",
"Lists of superlatives in astronomy"
] |
12,067,892 | https://en.wikipedia.org/wiki/NanoMemPro%20IPPC%20Database | The NanoMemPro IPPC database focus the operations where membranes are introduced as Best Available Techniques in the industrial areas addressed by the IPPC Directive.
The Integrated Pollution Prevention and Control (IPPC) Directive was adopted by the European Council on September 24, 1996. It defines the obligations with which highly polluting industrial and agricultural activities must comply.
It establishes a procedure for authorizing these activities: a permit is issued if certain environmental conditions are met.
The IPPC Directive aims to minimise pollution from various sources throughout the European Union (it concerns both new and existing installations). To do so, all industrial installations covered by the Annex I of the IPPC Directive (see ) are required to obtain an authorisation (permit) from the authorities in the EU countries before they are allowed to operate. The permits granted must be based on the concept of Best Available Techniques (or BAT).
Features
The IPPC Directive covers 33 industrial sectors where in almost all of them membrane processes appear as BAT, not only as an end-of-pipe solution for effluent treatment but mainly as a part of the industrial production processes.
Membrane process integration play a crucial role, depending on the industrial sector in which they are integrated, and these roles may be:
Confinement of pollutants in concentrate streams (that may be further treated by destructive processes),
Permeate recycle or re-use in the industrial process, thus reducing water input and discharge,
Water recycling and effluent minimization, tending to zero discharge industrial processes.
The IPPC Database was designed by the NanoMemPro Network of Excellence to focus the operations where membranes are introduced as BAT in the industrial areas addressed by the IPPC Directive documents.
The Database built allows any user to search information upon the following criteria:
Membrane process (Reverse Osmosis, Nanofiltration, etc.),
Industrial sector (Pulp and Paper, Textile Industry, etc.),
State of Reference document approval (BREF, DRAFT, etc.).
The information states which membrane processes are defined as a BAT in a given industrial sector and what is the application/purpose of that membrane process(es).
When accessing the Database, one can enter a username and password. This password insertion is used only by the database manager. To view and search the information of the database, just press the OK button, ignoring the password insertion procedure.
This IPPC Database is available in the NanoMemPro website.
References
European Union law
Membrane technology
Scientific databases | NanoMemPro IPPC Database | [
"Chemistry"
] | 508 | [
"Membrane technology",
"Separation processes"
] |
12,068,693 | https://en.wikipedia.org/wiki/Archaeosporales | Archaeosporales is an order of fungi best known as arbuscular mycorrhiza to vascular land plants (Tracheophyta). But also form free living endocyte symbioses with cyanobacteria. The free living forms may have a Precambrian fossil record back 2.2 Ga, well before evolution of Tracheophyta. However, the earliest fossils of Opisthokonta otherwise date back to the early Tonian, thus making this possibility questionable.
References
Glomeromycota
Fungus orders | Archaeosporales | [
"Biology"
] | 117 | [
"Fungus stubs",
"Fungi"
] |
12,068,712 | https://en.wikipedia.org/wiki/Paraglomerales | The Paraglomerales are a group of exclusively hypogeous (underground) arbuscular mycorrhizal fungi that rarely produce vesicles and reproduce through unpigmented spores. It includes the species Paraglomus brasilianum, Paraglomus laccatum, and Paraglomus occultum.
References
Glomeromycota
Fungus orders | Paraglomerales | [
"Biology"
] | 81 | [
"Fungus stubs",
"Fungi"
] |
12,069,013 | https://en.wikipedia.org/wiki/Recurrence%20period%20density%20entropy | Recurrence period density entropy (RPDE) is a method, in the fields of dynamical systems, stochastic processes, and time series analysis, for determining the periodicity, or repetitiveness of a signal.
Overview
Recurrence period density entropy is useful for characterising the extent to which a time series repeats the same sequence, and is therefore similar to linear autocorrelation and time delayed mutual information, except that it measures repetitiveness in the phase space of the system, and is thus a more reliable measure based upon the dynamics of the underlying system that generated the signal. It has the advantage that it does not require the assumptions of linearity, Gaussianity or dynamical determinism. It has been successfully used to detect abnormalities in biomedical contexts such as speech signal.
The RPDE value is a scalar in the range zero to one. For purely periodic signals, , whereas for purely i.i.d., uniform white noise, .
Method description
The RPDE method first requires the embedding of a time series in phase space, which, according to stochastic extensions to Taken's embedding theorems, can be carried out by forming time-delayed vectors:
for each value xn in the time series, where M is the embedding dimension, and τ is the embedding delay. These parameters are obtained by systematic search for the optimal set (due to lack of practical embedding parameter techniques for stochastic systems) (Stark et al. 2003). Next, around each point in the phase space, an -neighbourhood (an m-dimensional ball with this radius) is formed, and every time the time series returns to this ball, after having left it, the time difference T between successive returns is recorded in a histogram. This histogram is normalised to sum to unity, to form an estimate of the recurrence period density function P(T). The normalised entropy of this density:
is the RPDE value, where is the largest recurrence value (typically on the order of 1000 samples). Note that RPDE is intended to be applied to both deterministic and stochastic signals, therefore, strictly speaking, Taken's original embedding theorem does not apply, and needs some modification.
RPDE in practice
RPDE has the ability to detect subtle changes in natural biological time series such as the breakdown of regular periodic oscillation in abnormal cardiac function which are hard to detect using classical signal processing tools such as the Fourier transform or linear prediction. The recurrence period density is a sparse representation for nonlinear, non-Gaussian and nondeterministic signals, whereas the Fourier transform is only sparse for purely periodic signals.
See also
Recurrence plot, a powerful visualisation tool of recurrences in dynamical (and other) systems.
Recurrence quantification analysis, another approach to quantify recurrence properties.
References
External links
Fast MATLAB code for calculating the RPDE value.
http://www.recurrence-plot.tk/
Signal processing
Entropy
Stochastic processes
Dynamical systems | Recurrence period density entropy | [
"Physics",
"Chemistry",
"Mathematics",
"Technology",
"Engineering"
] | 652 | [
"Thermodynamic properties",
"Telecommunications engineering",
"Physical quantities",
"Computer engineering",
"Signal processing",
"Quantity",
"Entropy",
"Mechanics",
"Asymmetry",
"Wikipedia categories named after physical quantities",
"Symmetry",
"Dynamical systems"
] |
17,574,835 | https://en.wikipedia.org/wiki/Blind%20flying%20panel | A blind flying panel is an instrumentation sub-panel located in the cockpit of an aircraft. Its purpose was to present the necessary information to pilots for flying under instrument flight rules (IFR); it would be used in circumstances where visual flight rules (VFR) would not be desirable or possible, such as during night time or unclear weather conditions. The blind flying panel was prevalently used during the Second World War upon a wide range of aircraft, from fighters such as the Supermarine Spitfire, to bombers and trainers alike. In the postwar era, it decreased in relevance following the increasing prevalence of onboard radar sets and other newer navigational aids.
Description
A blind flying panel has typically, but not necessarily, features an arrangement of six key flight instruments: an airspeed indicator (ASI), an artificial horizon, an altimeter, a rate of climb indicator, a directional gyro, and a turn and slip indicator. All of the blind flying panel's instruments were either pitot/static-powered or vacuum powered, the latter being driven via a vacuum pump fitted onto (at least one of) the aircraft's engines, thus making the instruments independent of the electrical supply. However, some aircraft featured dimmable electrical lighting for illuminating these instruments. The blind flying panel was usually mounted away from the main panel, typically on an arrangement of three rubber suspension points.
Around the time of the Second World War, the blind flying panel was a standardised piece of cockpit equipment that was installed on the majority of aircraft operated by the Royal Air Force, to the point where it was considered to be a part of the typical British cockpit. The majority of fighter aircraft that participated in the Battle of Britain, including the Hawker Hurricane and Supermarine Spitfire, were so provisioned, as were numerous other aircraft, even trainers. Biplanes in British service, such as the Fairey Swordfish torpedo bomber, often featured blind instrument panels on later-built examples despite otherwise relatively spartan cockpits become commonplace.
In contrast, the Messerschmitt Bf 109 operated by the Luftwaffe were not furnished with blind flying panels. The United States developed its own standardised blind flying panel during the conflict, fitting it to several fighters, such as the Grumman F6F Hellcat. However, numerous American fighters, typically those built early on in the conflict such as the Bell P-39 Airacobra and the Curtiss P-40 Warhawk, lacked any such provision. Numerous early postwar era aircraft, such as the de Havilland Comet, the world's first jetliner, had blind flying panels amongst their navigational instrumentation.
During the 1950s, some analysts concluded that the standard blind flying panel was increasingly unable to meet special operational requirements, such as the need for pilots to view radar imagery, particularly in the night fighter role in which the panel had been once prolifically used in. Around this time, research was underway to developing methods of flying under IFR conditions without relying on gyroscopes or some of the traditional means of instrumentation. Nonetheless, the blind flying panel continued to be used by operational aircraft for quite some time, In addition to being subject to numerous studies and comparisons drawn with newer instrumentation designs.
References
Citations
Bibliography
Caygill, Peter. Flying to the Limit: Testing WW II Single-engined Fighters. Casemate Publishers, 2005. .
Nijboer, Donald. Fighting Cockpits: In the Pilot's Seat of Great Military Aircraft from World War I to Today. Voyageur Press, 2016. .
Simons, Graham M. Comet! The World's First Jet Airline. Pen and Sword, 2013. .
Wragg, David. Stringbag: The Fairey Swordfish at War. Pen and Sword, 2004. .
External links
Instrument - Not Blind Flying
Avionics | Blind flying panel | [
"Technology"
] | 767 | [
"Avionics",
"Aircraft instruments"
] |
17,575,156 | https://en.wikipedia.org/wiki/Bacterial%20motility | Bacterial motility is the ability of bacteria to move independently using metabolic energy. Most motility mechanisms that evolved among bacteria also evolved in parallel among the archaea. Most rod-shaped bacteria can move using their own power, which allows colonization of new environments and discovery of new resources for survival. Bacterial movement depends not only on the characteristics of the medium, but also on the use of different appendages to propel. Swarming and swimming movements are both powered by rotating flagella. Whereas swarming is a multicellular 2D movement over a surface and requires the presence of surfactants, swimming is movement of individual cells in liquid environments.
Other types of movement occurring on solid surfaces include twitching, gliding and sliding, which are all independent of flagella. Twitching depends on the extension, attachment to a surface, and retraction of type IV pili which pull the cell forwards in a manner similar to the action of a grappling hook, providing energy to move the cell forward. Gliding uses different motor complexes, such as the focal adhesion complexes of Myxococcus. Unlike twitching and gliding motilities, which are active movements where the motive force is generated by the individual cell, sliding is a passive movement. It relies on the motive force generated by the cell community due to the expansive forces caused by cell growth within the colony in the presence of surfactants, which reduce the friction between the cells and the surface. The overall movement of a bacterium can be the result of alternating tumble and swim phases. As a result, the trajectory of a bacterium swimming in a uniform environment will form a random walk with relatively straight swims interrupted by random tumbles that reorient the bacterium.
Bacteria can also exhibit taxis, which is the ability to move towards or away from stimuli in their environment. In chemotaxis the overall motion of bacteria responds to the presence of chemical gradients. In phototaxis bacteria can move towards or away from light. This can be particularly useful for cyanobacteria, which use light for photosynthesis. Likewise, magnetotactic bacteria align their movement with the Earth's magnetic field. Some bacteria have escape reactions allowing them to back away from stimuli that might harm or kill. This is fundamentally different from navigation or exploration, since response times must be rapid. Escape reactions are achieved by action potential-like phenomena, and have been observed in biofilms as well as in single cells such as cable bacteria.
Currently there is interest in developing biohybrid microswimmers, microscopic swimmers which are part biological and part engineered by humans, such as swimming bacteria modified to carry cargo.
Background
In 1828, the British biologist Robert Brown discovered the incessant jiggling motion of pollen in water and described his finding in his article "A Brief Account of Microscopical Observations…", leading to extended scientific discussion about the origin of this motion. This enigma was resolved only in 1905, when Albert Einstein published his celebrated essay Über die von der molekularkinetischen Theorie der Wärme geforderte Bewegung von in ruhenden Flüssigkeiten suspendierten Teilchen. Einstein not only deduced the diffusion of suspended particles in quiescent liquids, but also suggested these findings could be used to determine particle size — in a sense, he was the world's first microrheologist.
Ever since Newton established his equations of motion, the mystery of motion on the microscale has emerged frequently in scientific history, as famously demonstrated by a couple of articles that should be discussed briefly. First, an essential concept, popularized by Osborne Reynolds, is that the relative importance of inertia and viscosity for the motion of a fluid depends on certain details of the system under consideration. The Reynolds number , named in his honor, quantifies this comparison as a dimensionless ratio of characteristic inertial and viscous forces:
Here, represents the density of the fluid; is a characteristic velocity of the system (for instance, the velocity of a swimming particle); is a characteristic length scale (e.g., the swimmer size); and is the viscosity of the fluid. Taking the suspending fluid to be water, and using experimentally observed values for , one can determine that inertia is important for macroscopic swimmers like fish ( = 100), while viscosity dominates the motion of microscale swimmers like bacteria ( = 10−4).
The overwhelming importance of viscosity for swimming at the micrometer scale has profound implications for swimming strategy. This has been discussed memorably by E. M. Purcell, who invited the reader into the world of microorganisms and theoretically studied the conditions of their motion. In the first place, propulsion strategies of large scale swimmers often involve imparting momentum to the surrounding fluid in periodic discrete events, such as vortex shedding, and coasting between these events through inertia. This cannot be effective for microscale swimmers like bacteria: due to the large viscous damping, the inertial coasting time of a micron-sized object is on the order of 1 μs. The coasting distance of a microorganism moving at a typical speed is about 0.1 angstroms (Å). Purcell concluded that only forces that are exerted in the present moment on a microscale body contribute to its propulsion, so a constant energy conversion method is essential.
Microorganisms have optimized their metabolism for continuous energy production, while purely artificial microswimmers (microrobots) must obtain energy from the environment, since their on-board-storage-capacity is very limited. As a further consequence of the continuous dissipation of energy, biological and artificial microswimmers do not obey the laws of equilibrium statistical physics, and need to be described by non-equilibrium dynamics. Mathematically, Purcell explored the implications of low Reynolds number by taking the Navier-Stokes equation and eliminating the inertial terms:
where is the velocity of the fluid and is the gradient of the pressure. As Purcell noted, the resulting equation — the Stokes equation — contains no explicit time dependence. This has some important consequences for how a suspended body (e.g., a bacterium) can swim through periodic mechanical motions or deformations (e.g., of a flagellum). First, the rate of motion is practically irrelevant for the motion of the microswimmer and of the surrounding fluid: changing the rate of motion will change the scale of the velocities of the fluid and of the microswimmer, but it will not change the pattern of fluid flow. Secondly, reversing the direction of mechanical motion will simply reverse all velocities in the system. These properties of the Stokes equation severely restrict the range of feasible swimming strategies.
As a concrete illustration, consider a mathematical scallop that consists of two rigid pieces connected by a hinge. Can the "scallop" swim by periodically opening and closing the hinge? No: regardless of how the cycle of opening and closing depends on time, the scallop will always return to its starting point at the end of the cycle. Here originated the striking quote: "Fast or slow, it exactly retraces its trajectory and it's back where it started". In light of this scallop theorem, Purcell developed approaches concerning how artificial motion at the micro scale can be generated. This paper continues to inspire ongoing scientific discussion; for example, recent work by the Fischer group from the Max Planck Institute for Intelligent Systems experimentally confirmed that the scallop principle is only valid for Newtonian fluids.
Motile systems have developed in the natural world over time and length scales spanning several orders of magnitude, and have evolved anatomically and physiologically to attain optimal strategies for self-propulsion and overcome the implications of high viscosity forces and Brownian motion, as shown in the diagram on the right.
Some of the smallest known motile systems are motor proteins, i.e., proteins and protein complexes present in cells that carry out a variety of physiological functions by transducing chemical energy into mechanical energy. These motor proteins are classified as myosins, kinesins, or dyneins. Myosin motors are responsible for muscle contractions and the transport of cargousing actin filaments as tracks. Dynein motors and kinesin motors, on the other hand, use microtubules to transport vesicles across the cell. The mechanism these protein motors use to convert chemical energy into movement depends on ATP hydrolysis, which leads to a conformation modification in the globular motor domain, leading to directed motion.
Bacteria can be roughly divided into two fundamentally different groups, gram-positive and gram-negative bacteria, distinguished by the architecture of their cell envelope. In each case the cell envelope is a complex multi-layered structure that protects the cell from its environment. In gram-positive bacteria, the cytoplasmic membrane is only surrounded by a thick cell wall of peptidoglycan. By contrast, the envelope of gram-negative bacteria is more complex and consists (from inside to outside) of the cytoplasmic membrane, a thin layer of peptidoglycan, and an additional outer membrane, also called the lipopolysaccharide layer. Other bacterial cell surface structures range from disorganised slime layers to highly structured capsules. These are made from secreted slimy or sticky polysaccharides or proteins that provide protection for the cells and are in direct contact with the environment. They have other functions, including attachment to solid surfaces. Additionally, protein appendages can be present on the surface: fimbriae and pili can have different lengths and diameters and their functions include adhesion and twitching motility.
Specifically, for microorganisms that live in aqueous environments, locomotion refers to swimming, and hence the world is full of different classes of swimming microorganisms, such as bacteria, spermatozoa, protozoa, and algae. Bacteria move due to rotation of hair-like filaments called flagella, which are anchored to a protein motor complex on the bacteria cell wall.
Movement mechanisms
Bacteria have two different primary mechanisms they use for movement. The flagellum is used for swimming and swarming, and the pilus (or fimbria) is used for twitching.
Flagellum
The flagellum (plural, flagella; a group of flagella is called a tuft) is a helical, thin and long appendage attached to the cell surface by one of its ends, performing a rotational motion to push or pull the cell. During the rotation of the bacterial flagellar motor, which is located in the membrane, the flagella rotate at speeds between 200 and 2000 rpm, depending on the bacterial species. The hook substructure of the bacterial flagellum acts as a universal joint connecting the motor to the flagellar filament.
Prokaryotes, both bacteria and archaea, primarily use flagella for locomotion.
Bacterial flagella are helical filaments, each with a rotary motor at its base which can turn clockwise or counterclockwise. They provide two of several kinds of bacterial motility.
Archaeal flagella are called archaella, and function in much the same way as bacterial flagella. Structurally the archaellum is superficially similar to a bacterial flagellum, but it differs in many details and is considered non-homologous.
Some eukaryotic cells also use flagella — and they can be found in some protists and plants as well as animal cells. Eukaryotic flagella are complex cellular projections that lash back and forth, rather than in a circular motion. Prokaryotic flagella use a rotary motor, and the eukaryotic flagella use a complex sliding filament system. Eukaryotic flagella are ATP-driven, while prokaryotic flagella can be ATP-driven (archaea) or proton-driven (bacteria).
Different types of cell flagellation are found depending on the number and arrangement of the flagella on the cell surface, e.g., only at the cell poles or spread over the cell surface. In polar flagellation, the flagella are present at one or both ends of the cell: if a single flagellum is attached at one pole, the cell is called monotrichous; if a tuft of flagella is located at one pole, the cells is lophotrichous; when flagella are present at both ends, the cell is amphitrichous. In peritrichous flagellation, the flagella are distributed in different locations around the cell surface. Nevertheless, variations within this classification can be found, like lateral and subpolar—instead of polar—monotrichous and lophotrichous flagellation.
The rotary motor model used by bacteria uses the protons of an electrochemical gradient in order to move their flagella. Torque in the flagella of bacteria is created by particles that conduct protons around the base of the flagellum. The direction of rotation of the flagella in bacteria comes from the occupancy of the proton channels along the perimeter of the flagellar motor.
The bacterial flagellum is a protein-nanomachine that converts electrochemical energy in the form of a gradient of H+ or Na+ ions into mechanical work. The flagellum is composed of three parts: the basal body, the hook, and the filament. The basal body is a reversible motor that spans the bacterial cell envelope. It is composed of the central rod and several rings: in Gram-negative bacteria, these are the outer L-ring (lipopolysaccharide) and P-ring (peptidoglycan), and the inner MS-ring (membrane/supramembrane) and C-ring (cytoplasmic). In Gram-positive bacteria only the inner rings are present. The Mot proteins (MotA and MotB) surround the inner rings in the cytoplasmic membrane; ion translocation through the Mot proteins provide the energy for flagella rotation. The Fli proteins allow reversal of the direction of rotation of the flagella in response to specific stimuli. The hook connects the filament to the motor protein in the base. The helical filament is composed of many copies of the protein flagellin, and it can rotate clockwise (CW) and counterclockwise (CCW).
Pilus (fimbria)
A pilus (Latin for 'hair') is a hair-like appendage found on the surface of many bacteria and archaea. The terms pilus and fimbria (Latin for 'fringe') can be used interchangeably, although some researchers reserve the term pilus for the appendage required for bacterial conjugation. Dozens of these structures can exist on the bacterial and archaeal surface.
Twitching motility is a form of crawling bacterial motility used to move over surfaces. Twitching is mediated by the activity of a particular type of pilus called type IV pilus which extends from the cell's exterior, binds to surrounding solid substrates and retracts, pulling the cell forwards in a manner similar to the action of a grappling hook. Pili are not used just for twitching. They are also antigenic and are required for the formation of biofilm, as they attach bacteria to host surfaces for colonisation during infection. They are fragile and constantly replaced, sometimes with pili of different composition.
Other
Gliding motility is a type of translocation that is independent of propulsive structures such as flagella or pili. Gliding allows microorganisms to travel along the surface of low aqueous films. The mechanisms of this motility are only partially known. Gliding motility uses a highly diverse set of different motor complexes, including e.g., the focal adhesion complexes of Myxococcus. The speed of gliding varies between organisms, and the reversal of direction is seemingly regulated by some sort of internal clock.
Modes of locomotion
Most rod-shaped bacteria can move using their own power, which allows colonization of new environments and discovery of new resources for survival. Bacterial movement depends not only on the characteristics of the medium, but also on the use of different appendages to propel. Swarming and swimming movements are both powered by rotating flagella. Whereas swarming is a multicellular 2D movement over a surface and requires the presence of surfactant substances, swimming is movement of individual cells in liquid environments.
Other types of movement occurring on solid surfaces include twitching, gliding and sliding, which are all independent of flagella. Twitching motility depends on the extension, attachment to a surface, and retraction of type IV pili which provide the energy required to push the cell forward. Gliding motility uses a highly diverse set of different motor complexes, including e.g., the focal adhesion complexes of Myxococcus. Unlike twitching and gliding motilities, which are active movements where the motive force is generated by the individual cell, sliding is a passive movement. It relies on the motive force generated by the cell community due to the expansive forces caused by cell growth within the colony in the presence of surfactants, which reduce the friction between the cells and the surface.
Swimming
Many bacteria swim, propelled by rotation of the flagella outside the cell body. In contrast to protist flagella, bacterial flagella are rotors and — irrespective of species and type of flagellation — they have only two modes of operation: clockwise (CW) or counterclockwise (CCW) rotation. Bacterial swimming is used in bacterial taxis (mediated by specific receptors and signal transduction pathways) for the bacterium to move in a directed manner along gradients and reach more favorable conditions for life. The direction of flagellar rotation is controlled by the type of molecules detected by the receptors on the surface of the cell: in the presence of an attractant gradient, the rate of smooth swimming increases, while the presence of a repellent gradient increases the rate of tumbling.
The archetype of bacterial swimming is represented by the well-studied model organism Escherichia coli. With its peritrichous flagellation, E. coli performs a run-and-tumble swimming pattern, as shown in the diagram on the right. CCW rotation of the flagellar motors leads to flagellar bundle formation that pushes the cell in a forward run, parallel to the long axis of the cell. CW rotation disassembles the bundle and the cell rotates randomly (tumbling). After the tumbling event, straight swimming is recovered in a new direction. That is, CCW rotation results in steady motion and CW rotation in tumbling; CCW rotation in a given direction is maintained longer in the presence of molecules of interest (like sugars or aminoacids).
However, the type of swimming movement (propelled by rotation of flagella outside the cell body) varies significantly with the species and number/distribution of flagella on the cell body. For example, the marine bacterium Vibrio alginolyticus, with its single polar flagellum, swims in a cyclic, three-step (forward, reverse, and flick) pattern. Forward swimming occurs when the flagellum pushes the cell head, while backward swimming is based on the flagellum pulling the head upon motor reversal.
Besides these 180° reversals, the cells can reorient (a "flick") by an angle around 90°, referred to as turning by buckling. Rhodobacter sphaeroides with its subpolar monotrichous flagellation, represents yet another motility strategy: the flagellum only rotates in one direction, and it stops and coils against the cell body from time to time, leading to cell body reorientations, In the soil bacterium Pseudomonas putida, a tuft of helical flagella is attached to its posterior pole. P. putida alternates between three swimming modes: pushing, pulling, and wrapping.
In the pushing mode, the rotating flagella (assembled in a bundle or as an open tuft of individual filaments) drive the motion from the rear end of the cell body. The trajectories are either straight or, in the vicinity of a solid surface, curved to the right, due to hydrodynamic interaction of the cell with the surface. The direction of curvature indicates that pushers are driven by a left-handed helix turning in CCW direction. In the pulling mode, the rotating flagellar bundle is pointing ahead. In this case the trajectories are either straight or with a tendency to bend to the left, indicating that pullers swim by turning a left-handed helical bundle in CW direction. Finally, P. putida can swim by wrapping the filament bundle around its cell body, with the posterior pole pointing in the direction of motion. In that case, the flagellar bundle takes the form of a left-handed helix that turns in CW direction, and the trajectories are predominantly straight.
Swarming
Swarming motility is a rapid (2–10 μm/s) and coordinated translocation of a bacterial population across solid or semi-solid surfaces, and is an example of bacterial multicellularity and swarm behaviour. Swarming motility was first reported in 1972 by Jorgen Henrichsen.
The transition from swimming to swarming mobility is usually associated with an increase in the number of flagella per cell, accompanied by cell elongation. Experiments with Proteus mirabilis showed that swarming requires contact between cells: swarming cells move in side-by-side groups called rafts, which dynamically add or lose cells: when a cell is left behind the raft, its movement stops after a short time; when a group of cells moving in a raft make contact with a stationary cell, it is reactivated and incorporated into the raft. More recently, Swiecicki and coworkers designed a polymer microfluidic system to confine E. coli cells in a quasi-two-dimensional layer of motility buffer in order to study different behaviors of cells transitioning from swimming to swarming movement. For this, they forced E. coli planktonic cells into a swarming-cell-phenotype by inhibiting cell division (leading to cell elongation) and by deletion of the chemosensory system (leading to smooth swimming cells that do not tumble). The increase of bacterial density inside the channel led to the formation of progressively larger rafts. Cells colliding with the raft contributed to increase its size, while cells moving at a velocity different from the mean velocity within the raft separated from it.
Cell trajectories and flagellar motion during swarming was thoroughly studied for E. coli, in combination with fluorescently labeled flagella. The authors described four different types of tracks during bacterial swarming: forward movement, reversals, lateral movement, and stalls. In forward movement, the long axis of the cell, the flagellar bundle and the direction of movement are aligned, and propulsion is similar to the propulsion of a freely swimming cell. In a reversal, the flagellar bundle loosens, with the filaments in the bundle changing from their "normal form" (left-handed helices) into a "curly" form of right-handed helices with lower pitch and amplitude. Without changing its orientation, the cell body moves backwards through the loosened bundle. The bundle re-forms from curly filaments on the opposite pole of the cell body, and the filaments eventually relax back into their normal form. Lateral motion can be caused by collisions with other cells or by a motor reversal. Finally, stalled cells are paused but the flagella continue spinning and pumping fluid in front of the swarm, usually at the swarm edge.
Twitching
Twitching motility is a form of crawling bacterial motility used to move over surfaces. Twitching is mediated by the activity of hair-like filaments called type IV pili which extend from the cell's exterior, bind to surrounding solid substrates and retract, pulling the cell forwards in a manner similar to the action of a grappling hook. The name twitching motility is derived from the characteristic jerky and irregular motions of individual cells when viewed under the microscope.
A bacterial biofilm is a bacterial community attached into a surface through extracellular polymeric materials. Prior to biofilm formation, bacteria may need to deposit on the surface from their planktonic state. After bacteria deposit on surfaces they may "twitch" or crawl over the surface using appendages called type IV pili to "explore" the substratum to find suitable sites for growth and thus biofilm formation. Pili emanate from bacterial surface and they can be up to several micrometres long (though they are nanometres in diameter). Bacterial twitching occurs through cycles of polymerization and depolymerization of type IV pili. Polymerization causes the pilus to elongate and eventually attaching into surfaces. Depolymerization makes the pilus retract and detach from the surfaces. Pili retraction produces pulling forces on the bacterium, which will be pulled in the direction of the vector sum of the pili forces, resulting in a jerky movement. A typical type IV pilus can produce a force exceeding 100 piconewtons and then a bundle of pili can produce pulling forces up to several nanonewtons. Bacteria may use pili not only for twitching but also for cell-cell interactions, surface sensing, and DNA uptake.
Gliding
Gliding motility is a type of translocation that is independent of propulsive structures such as flagella or pili. Gliding allows microorganisms to travel along the surface of low aqueous films. The mechanisms of this motility are only partially known. The speed of gliding varies between organisms, and the reversal of direction is seemingly regulated by some sort of internal clock. For example the apicomplexans are able to travel at fast rates between 1–10 μm/s. In contrast Myxococcus xanthus, a slime bacterium, can glide at a rate of 5 μm/min. In myxobacteria individual bacteria move together to form waves of cells that then differentiate to form fruiting bodies containing spores. Myxobacteria move only when on solid surfaces, unlike say E. coli, which is motile in liquid or solid media.
Non-motile
Non-motile species lack the ability and structures that would allow them to propel themselves, under their own power, through their environment. When non-motile bacteria are cultured in a stab tube, they only grow along the stab line. If the bacteria are mobile, the line will appear diffuse and extend into the medium.
Bacterial taxis: Directed motion
Bacteria are said to exhibit taxis if they move in a manner directed toward or away from some stimulus in their environment. This behaviour allows bacteria to reposition themselves in relation to the stimulus. Different types of taxis can be distinguished according to the nature of the stimulus controlling the directed movement, such as chemotaxis (chemical gradients like glucose), aerotaxis (oxygen), phototaxis (light), thermotaxis (heat), and magnetotaxis (magnetic fields).
Chemotaxis
The overall movement of a bacterium can be the result of alternating tumble and swim phases. As a result, the trajectory of a bacterium swimming in a uniform environment will form a random walk with relatively straight swims interrupted by random tumbles that reorient the bacterium. Bacteria such as E. coli are unable to choose the direction in which they swim, and are unable to swim in a straight line for more than a few seconds due to rotational diffusion; in other words, bacteria "forget" the direction in which they are going. By repeatedly evaluating their course, and adjusting if they are moving in the wrong direction, bacteria can direct their random walk motion toward favorable locations.
In the presence of a chemical gradient bacteria will chemotax, or direct their overall motion based on the gradient. If the bacterium senses that it is moving in the correct direction (toward attractant/away from repellent), it will keep swimming in a straight line for a longer time before tumbling; however, if it is moving in the wrong direction, it will tumble sooner. Bacteria like E. coli use temporal sensing to decide whether their situation is improving or not, and in this way, find the location with the highest concentration of attractant, detecting even small differences in concentration.
This biased random walk is a result of simply choosing between two methods of random movement; namely tumbling and straight swimming. The helical nature of the individual flagellar filament is critical for this movement to occur. The protein structure that makes up the flagellar filament, flagellin, is conserved among all flagellated bacteria. Vertebrates seem to have taken advantage of this fact by possessing an immune receptor (TLR5) designed to recognize this conserved protein.
As in many instances in biology, there are bacteria that do not follow this rule. Many bacteria, such as Vibrio, are monoflagellated and have a single flagellum at one pole of the cell. Their method of chemotaxis is different. Others possess a single flagellum that is kept inside the cell wall. These bacteria move by spinning the whole cell, which is shaped like a corkscrew.
The ability of marine microbes to navigate toward chemical hotspots can determine their nutrient uptake and has the potential to affect the cycling of elements in the ocean. The link between bacterial navigation and nutrient cycling highlights the need to understand how chemotaxis functions in the context of marine microenvironments. Chemotaxis hinges on the stochastic binding/unbinding of molecules with surface receptors, the transduction of this information through an intracellular signaling cascade, and the activation and control of flagellar motors. The intrinsic randomness of these processes is a central challenge that cells must deal with in order to navigate, particularly under dilute conditions where noise and signal are similar in magnitude. Such conditions are ubiquitous in the ocean, where nutrient concentrations are often extremely low and subject to rapid variation in space (e.g., particulate matter, nutrient plumes) and time (e.g., diffusing sources, fluid mixing).
The fine-scale interactions between marine bacteria and both dissolved and particulate organic matter underpin marine biogeochemistry, thereby supporting productivity and influencing carbon storage and sequestration in the planet's oceans. It has been historically very difficult to characterize marine environments on the microscales that are most relevant to individual bacteria. Rather, research efforts have typically sampled much larger volumes of water and made comparisons from one sampling site to another. However, at the length scales relevant to individual microbes, the ocean is an intricate and dynamic landscape of nutrient patches, at times too small to be mixed by turbulence. The capacity for microbes to actively navigate these structured environments using chemotaxis can strongly influence their nutrient uptake. Although some work has examined time-dependent chemical profiles, past investigations of chemotaxis using E. coli and other model organisms have routinely examined steady chemical gradients strong enough to elicit a discernible chemotactic response. However, the typical chemical gradients wild marine bacteria encounter are often very weak, ephemeral in nature, and with low background concentrations. Shallow gradients are relevant for marine bacteria because, in general, gradients become weaker as one moves away from the source. Yet, detecting such gradients at distance has tremendous value, because they point toward nutrient sources. Shallow gradients are important precisely because they can be used to navigate to regions in the vicinity of sources where gradients become steep, concentrations are high, and bacteria can acquire resources at a high rate.
Phototaxis
Phototaxis is a kind of taxis, or locomotory movement, that occurs when a whole organism moves towards or away from a stimulus of light. This is advantageous for phototrophic organisms as they can orient themselves most efficiently to receive light for photosynthesis. Phototaxis is called positive if the movement is in the direction of increasing light intensity and negative if the direction is opposite.
Two types of positive phototaxis are observed in prokaryotes. The first is called "scotophobotaxis" (from the word "scotophobia"), which is observed only under a microscope. This occurs when a bacterium swims by chance out of the area illuminated by the microscope. Entering darkness signals the cell to reverse flagella rotation direction and reenter the light. The second type of phototaxis is true phototaxis, which is a directed movement up a gradient to an increasing amount of light. This is analogous to positive chemotaxis except that the attractant is light rather than a chemical.
Phototactic responses are observed in a number of bacteria and archae, such as Serratia marcescens. Photoreceptor proteins are light-sensitive proteins involved in the sensing and response to light in a variety of organisms. Some examples are bacteriorhodopsin and bacteriophytochromes in some bacteria. See also: phytochrome and phototropism.
Most prokaryotes (bacteria and archaea) are unable to sense the direction of light, because at such a small scale it is very difficult to make a detector that can distinguish a single light direction. Still, prokaryotes can measure light intensity and move in a light-intensity gradient. Some gliding filamentous prokaryotes can even sense light direction and make directed turns, but their phototactic movement is very slow. Some bacteria and archaea are phototactic.
In most cases the mechanism of phototaxis is a biased random walk, analogous to bacterial chemotaxis. Halophilic archaea, such as Halobacterium salinarum, use sensory rhodopsins (SRs) for phototaxis. Rhodopsins are 7 transmembrane proteins that bind retinal as a chromophore. Light triggers the isomerization of retinal, which leads to phototransductory signalling via a two-component phosphotransfer relay system. Halobacterium salinarum has two SRs, SRI and SRII, which signal via the transducer proteins HtrI and HtrII (halobacterial transducers for SRs I and II), respectively. The downstream signalling in phototactic archaebacteria involves CheA, a histidine kinase, which phosphorylates the response regulator, CheY. Phosphorylated CheY induces swimming reversals. The two SRs in Halobacterium have different functions. SRI acts as an attractant receptor for orange light and, through a two-photon reaction, a repellent receptor for near-UV light, while SRII is a repellent receptor for blue light. Depending on which receptor is expressed, if a cell swims up or down a steep light gradient, the probability of flagellar switch will be low. If light intensity is constant or changes in the wrong direction, a switch in the direction of flagellar rotation will reorient the cell in a new, random direction. As the length of the tracks is longer when the cell follows a light gradient, cells will eventually get closer to or further away from the light source. This strategy does not allow orientation along the light vector and only works if a steep light gradient is present (i.e. not in open water).
Some cyanobacteria (e.g. Anabaena, Synechocystis) can slowly orient along a light vector. This orientation occurs in filaments or colonies, but only on surfaces and not in suspension. The filamentous cyanobacterium Synechocystis is capable of both positive and negative two-dimensional phototactic orientation. The positive response is probably mediated by a bacteriophytochrome photoreceptor, TaxD1. This protein has two chromophore-binding GAF domains, which bind biliverdin chromophore, and a C-terminal domain typical for bacterial taxis receptors (MCP signal domain). TaxD1 also has two N-terminal transmembrane segments that anchor the protein to the membrane. The photoreceptor and signalling domains are cytoplasmic and signal via a CheA/CheY-type signal transduction system to regulate motility by type IV pili. TaxD1 is localized at the poles of the rod-shaped cells of Synechococcus elongatus, similarly to MCP containing chemosensory receptors in bacteria and archaea. How the steering of the filaments is achieved is not known. The slow steering of these cyanobacterial filaments is the only light-direction sensing behaviour prokaryotes could evolve owing to the difficulty in detecting light direction at this small scale.
Magnetotaxis
Magnetotactic bacteria orient themselves along the magnetic field lines of Earth's magnetic field. This alignment is believed to aid these organisms in reaching regions of optimal oxygen concentration. To perform this task, these bacteria have biomineralised organelles called magnetosomes that contain magnetic crystals. The biological phenomenon of microorganisms tending to move in response to the environment's magnetic characteristics is known as magnetotaxis. However, this term is misleading in that every other application of the term taxis involves a stimulus-response mechanism. In contrast to the magnetoreception of animals, the bacteria contain fixed magnets that force the bacteria into alignment—even dead cells are dragged into alignment, just like a compass needle.
Escape response
An escape response is a form of negative taxis. Stimuli that have the potential to harm or kill demand rapid detection. This is fundamentally distinct from navigation or exploration, in terms of the timescales available for response. Most motile species harbour a form of phobic or emergency response distinct from their steady state locomotion. Escape reactions are not strictly oriented—but commonly involve backward movement, sometimes with a negatively geotactic component. In bacteria and archaea, action potential-like phenomena have been observed in biofilms and also single cells such as cable bacteria. The archaeon Halobacterium salinarium shows a photophobic response characterized by a 180° reversal of its swimming direction induced by a reversal in the direction of flagellar rotation. At least some aspects of this response are likely mediated by changes in membrane potential by bacteriorhodopsin, a light-driven proton pump. Action potential-like phenomena in prokaryotes are dissimilar from classical eukaryotic action potentials. The former are less reproducible, slower and exhibit a broader distribution in pulse amplitude and duration.
Other taxes
Aerotaxis is the response of an organism to variation in oxygen concentration, and is mainly found in aerobic bacteria.
Energy taxis is the orientation of bacteria towards conditions of optimal metabolic activity by sensing the internal energetic conditions of cell. Therefore, in contrast to chemotaxis (taxis towards or away from a specific extracellular compound), energy taxis responds on an intracellular stimulus (e.g. proton motive force, activity of NDH- 1) and requires metabolic activity.
Mathematical modelling
The mathematical models used to describe the bacterial swimming dynamics can be classified into two categories. The first category is based on a microscopic (i.e. cell-level) view of bacterial swimming through a set of equations where each equation describes the state of a single agent. The second category provides a macroscopic (i.e. population-level) view via continuum-based partial differential equations that capture the dynamics of population density over space and time, without considering the intracellular characteristics directly.
Among the present models, Schnitzer uses the Smoluchowski equation to describe the biased random walk of the bacteria during chemotaxis to search for food. To focus on a detailed description of the motion taking place during one run interval of the bacteria, de Gennes derives the average run length travelled by bacteria during one counterclockwise interval. Along the same direction, to consider the environmental condition affecting the biased random walk of bacteria, Croze and his co-workers study experimentally and theoretically the effect of concentration of soft agar on chemotaxis of bacteria.
To study the effect of obstacles (another environmental condition) on the motion of bacteria, Chepizhko and his co-workers study the motion of self-propelled particles in a heterogeneous two-dimensional environment and show that the mean square displacement of particles is dependent on the density of obstacles and the particle turning speed. Building on these models, Cates highlights that bacterial dynamics does not always obey detailed balance, which means it is a biased diffusion process depending on the environmental conditions. Moreover, Ariel and his co-workers focus on diffusion of bacteria and show that the bacteria perform super-diffusion during swarming on a surface.
See also
Cyanobacterial movement
Protist locomotion
References
External links
Review of the hydrodynamics of bacterial swimming:
On-line text book on bacteriology (2015)
Bacteria
Bacteriology
Microswimmers | Bacterial motility | [
"Physics",
"Biology"
] | 8,610 | [
"Physical phenomena",
"Prokaryotes",
"Microswimmers",
"Motion (physics)",
"Bacteria",
"Microorganisms"
] |
17,576,622 | https://en.wikipedia.org/wiki/Salicornia%20quinqueflora | Salicornia quinqueflora, synonym Sarcocornia quinqueflora, commonly known as beaded samphire, bead weed, beaded glasswort or glasswort, is a species of succulent halophytic coastal shrub. It occurs in wetter coastal areas of Australia and New Zealand.
Historically, people used to burn glassworts to collect the ashes. The ashes contained a high amount of soda in them, which was used to make soap and glass. This is thought to be how glasswort received its name.
Description
Beaded glasswort, Salicornia quinqueflora, is a species of succulent, salt tolerant plant. It grows as a small shrub, with a lifecycle of several years – which is also known as a perennial lifecycle. They are normally found near salt water bodies (along the coast or estuaries) and grow in a mat form along the ground. The stems are jointed and fleshy when young, but they dry out and appear woody when ageing. The young, fleshy stems are grey or green with sometimes red colouring along the tips. The leaves grow opposite to each other and are connected at the base. They grow on small bumpy petioles – which is the part of a stalk that attaches the leaf to the stem. The leaves then extend down the stem – which in turn, forms the noticeable joints. The leaves look like tiny blades, wrapped around the stem. This formation of the leaves gives the stems a ‘beaded’ look. Growing at the end of the stem, the inflorescences (another name for clusters of flowers) are spikey, and made up of small segments with largecymes. Cymes are a group of flowers with a central stem that matures before the others. Each cyme usually has three flowers entirely immersed in the fleshy part of the joint. The unisex or bisexual flowers are nearly always identical in size and grow in an outwardly symmetrical style along the stems. The flowers have three to four fleshy exterior parts that connect to the apex (highest part of the stem), one or two stamens (the pollen-producing reproductive organ) and an ovary with two or three parts that hold the pollen (the stigma). There is a lot of fruit found in the outer part of the flower, and the fruit wall has a membrane. The seeds are vertical and spherical in shape, light brown, hairy and also have a membrane on the exterior. The hairs take on many forms – they can be angular, slight, curved, conic or straight. There is no feeding tissue (also known as the perisperm) within the seed.
Reproduction and life cycle
Glassworts are perennials, meaning that they go through many reproductive cycles and they do not necessarily need to produce genetically unique seeds all the time. For this reason, they often use ramets to propagate clonally. They make genetically identical copies of the healthiest organisms to spread quickly and asexually. When growth is strong and the environment is right, glassworts will produce genets, a genetically unique individual through seeds in order to keep the population diverse and evolving. Ranets often remain connected to the parent plant in order to survive in harsh conditions until they are fully developed and do not have enough nutrients and water to survive on their own. Seeds generally germinate during the early spring when temperatures begin to warm.
Flowers
Salicornia quinqueflora is characterized as gynodioecious, meaning that there are populations containing only hermaphrodite plants as well as populations containing both female and hermaphrodite plants. Most populations are entirely hermaphrodite except for the coasts of Nelson & Foxton, Tasman Bays, and the central regions of Otago in New Zealand. For the hermaphrodite flowers, they are protogynous. This means that the female stigma matures before the male anther to prevent self-fertilization. For these hermaphrodites, the stigma protrudes 1–2 days before the anther, and the stigma are then visible for 4–6 days. Anthers are revealed individually, one at a time. Anthers open up in the early morning to release pollen. This pollen is then distributed by wind. The flowers produce no nectar and are generally not pollinated by insects. Although, introduced honeybee, Apis mellifera, has been recorded visiting the flowers of the plant and collecting pollen on parts of its body, so this species is thought to possibly help spread pollen. For the female flowers, the stigma protrudes at the same time as the anthers of the hermaphrodite plants. This allows the pollen from the hermaphrodite plants to fertilize the female plants, and the life cycle can begin.
Taxonomy
It was first published as Salicornia quinqueflora in 1866, but transferred into Sarcocornia when that genus was erected in 1977. The Maori name is ureure. Molecular phylogenetic studies showed that when Salicornia and Sarcocornia are separated, Sarcocornia is paraphyletic, since Salicornia evolved within Sarcocornia. A study in 2017 confirmed the paraphyly of Sarcocornia, and merged the genus into Salicornia. This placement is accepted by sources such as Plants of the World Online and the New Zealand Plant Conservation Network.
Distribution and habitat
Natural global habitat
Salicornia quinqueflora is not endemic to New Zealand. In New Zealand it is found mostly on the shoreline in regions throughout the North Island. In the South Island S. quinqueflora is widespread on the east coast, but isn't found on the west coast. In Australia it occurs on the south west and south east areas, and also in parts of the Nullarbor Plain, and part of the east coast of Cape York Peninsula.
New Zealand range
In New Zealand, the species is found in mainly coastal areas. It can be found on all islands of New Zealand – including Stewart and the Chatham Islands. Glasswort grows on both coasts of the North Island and down the east coast of the South Island. Interestingly, it is also found in Central Otago, in two locations, roughly 70 km inland.
Habitat preferences
The preferred habitat of Salicornia quinqueflora is anywhere where salty water tends to be – so along coastlines, salt marshes, sandy beaches and rocky areas. It grows below and above the high tide mark along the coasts.
Soil preferences
The species is a halophyte, so it prefers soils with high salinities. This is the main factor determining its success. It is typically found in areas with high moisture levels because of the high salinity of the soils near coastlines; however, glassworts are tolerable to a wide range of soil moistures. They can handle areas with completely dry soil and soils that are completely water logged. Salicornia quinqueflora has a healthy population in Otago, where it is extremely dry and arid. It also has a large population on the extremely wet coastlines of Nelson.
Environmental preferences
Like other halophytes, Salicornia quinqueflora can handle a wide range of temperatures and are evolved to handle sudden environmental changes. Producing offspring through clonal reproduction allows them to survive in conditions that are less than ideal . The preferred climate type is warm-temperate and subtropical regions . where they can easily reproduce through seeds to keep populations genetically stable.
Threats and predators
Invasive species
The introduction of invasive species into the endemic regions for beaded glasswort are a major cause of habitat loss. Non-native species tend to grow quicker and faster than the native glasswort, allowing them to easily overtake their habitats. One example of this is in Victoria, Australia where Invasive Cordgrass (Spartina spp.) has changed the makeup of the intertidal sediment flats. The introduction of cordgrass caused these habitats to transform into marshlands. The previous intertidal habitat was important for the survival of the glasswort species, so the transition to marshland left the native glasswort without its habitat.
Glasswort gall mite
The glasswort gall mite, Aceria rubifaciens, was discovered in Auckland in 1948 and rediscovered in 2013 in an estuary near the Firth of Thames. This tiny, endemic mite only feeds on the glasswort, which the feeding causes pocket galls on the fresh, young stems. The mites live inside the galls which offer them protection from larger predators and weather conditions.
There is not a lot known about these tiny mites, mainly because they have only been found on Salicornia quinqueflora. So far it has only been found in the North Island, but it can be assumed that it would affect the other populations throughout New Zealand.
Other predators
Glasswort is also edible and palatable, so is known to have been consumed by both animals and humans. It could then be argued that both animals and humans are also considered predators of glasswort.
Other information
Habitat in inland Otago
Salicornia quinqueflora has been found growing in inland regions of Central Otago, the Maniototo Plain. This is odd because of its liking for salty soils near coastal areas. The Maniototo plain has developed highly saline soils due to the extreme dryness of the area. As rocks erode, the soil became more and more salty, and there was not enough rain to wash the salt away. This left the soil salty enough to support the glasswort. As the seeds were transported into the area by birds, the plant began to grow in the inland region.
Food Source for orange-bellied parrot
One species known to rely heavily on the glasswort is the orange-bellied parrot (Neophema chrysogaster). This parrot is critically endangered, having only around 180 individuals left in the wild. This native Australian bird feeds primarily on the seeds of Salicornia quinqueflora. As habitats for the glasswort decline due to human development, it becomes harder for the parrot to find the amount of seeds it needs to survive.
Glasswort use in recipes
Glasswort, apart from being a subshrub that can grow in incredibly harsh conditions, is also an edible plant. It is recommended to eat the fresh, young, upper parts of the glasswort stems raw, as they are tender and more flavourful. People are able to eat glasswort on its own, like in a salad, or mixed with other salad ingredients. It can also be used as a garnish with seafood – similar to how restaurants use parsley or watercress. The natural salty content and flavor means that glasswort is good in soups or stews for extra flavour, or can be served as a hot vegetable as well. Using the fresh parts of the stems, glasswort can also be pickled – but very carefully, as like anything when pickling.
There are also certain medicinal properties to glasswort. It is high in Vitamin C, Vitamin A and the B-complex vitamins and has also been described as helping flatulence and digestion. There are also certain glycosides, the bioflavonoid quercetin and isorhamnetin, which have been mentioned as possible aids for cancer.
References
External links
Online Field guide to Common Saltmarsh Plants of Queensland
quinqueflora
Flora of Queensland
Flora of New South Wales
Flora of Victoria (state)
Flora of South Australia
Eudicots of Western Australia
Halophytes
Caryophyllales of Australia
Plants described in 1866
Flora of New Zealand | Salicornia quinqueflora | [
"Chemistry"
] | 2,422 | [
"Halophytes",
"Salts"
] |
17,577,108 | https://en.wikipedia.org/wiki/CPU%20shielding | CPU shielding is a practice where on a multiprocessor system or on a CPU with multiple cores, real-time tasks can run on one CPU or core while non-real-time tasks run on another.
The operating system must be able to set a CPU affinity for both processes and interrupts.
Kernel space
In Linux in order to shield CPUs from individual interrupts being serviced on them you have to make sure that the following kernel configuration parameter is set:
CONFIG_IRQBALANCE
See also
Multi-core
Multiprocessing
Processor affinity
Real-time computing
External links
Shielded CPUs: Real-Time Performance in Standard Linux
Operating system technology
Real-time computing | CPU shielding | [
"Technology"
] | 137 | [
"Operating system stubs",
"Computing stubs",
"Real-time computing"
] |
17,577,602 | https://en.wikipedia.org/wiki/Pesticide%20formulation | The biological activity of a pesticide, be it chemical or biological in nature, is determined by its active ingredient (AI - also called the active substance). Pesticide products very rarely consist of the pure active ingredient. The AI is usually formulated with other materials (adjuvents and co-formulants) and this is the product as sold, but it may be further diluted in use. Formulations improve the properties of a chemical for handling, storage, application and may substantially influence effectiveness and safety.
Formulation terminology follows a 2-letter convention: (e.g. GR: granules) listed by CropLife International (formerly GIFAP then GCPF) in the Catalogue of Pesticide Formulation Types (Monograph 2); see: download page. Some manufacturers do not follow these industry standards, which can cause confusion for users.
Water-miscible formulations
By far the most frequently used products are formulations for mixing with water then applying as sprays.
Water miscible, older formulations include:
EC Emulsifiable concentrate
WP Wettable powder
SL Soluble (liquid) concentrate
SP Soluble powder
Newer, non-powdery formulations with reduced or no use of hazardous solvents and improved stability include:
SC Suspension concentrate
CS Capsule suspensions
WG Water dispersible granules
Other formulations
Other common formulations include granules (GR) and dusts (DP), although for improved safety the latter have been replaced by microgranules (MG e.g. for rice farmers in Japan). Specialist formulations are available for ultra-low volume spraying, fogging, fumigation, etc. Very occasionally, some pesticides (e.g. malathion) may be sold as technical material (TC - which is mostly AI, but also contains small quantities of, usually non-active, by-products of the manufacturing process; TGAC - "technical grade active constituent" means the same.).
A particularly efficient form of pesticide dose transfer is seed treatment and specific formulations have been developed for this purpose. A number of pesticide bait formulations are available for rodent pest control, etc.
In reality many formulation codes are used: AB, AE, AL, AP, BB, BR, CB, CF, CG, CL, CP, CS, DC, DL, DP, DS, DT, EC, ED, EG, EO, ES, EW, FD, FG, FK, FP, FR, FS, FT, FU, FW, GA, GB, GE, GF, GG, GL, GP, GR, GS, GW, HN, KK, KL, KN, KP, LA, LS, LV, MC, ME, MG, MV, OD, OF, OL, OP, PA, PB, PC, PO, PR, PS, RB, SA, SB, SC, SD, SE, SG, SL, SO, SP, SS, ST, SU, TB, TC, TK, TP, UL, VP, WG, WP, WS, WT, XX, ZC, ZE and ZW.
See also
Formulations
Pharmaceutical formulation
Galenic formulation
References
Further reading
Burges, H.D. (ed.) (1998) Formulation of Microbial Biopesticides, beneficial microorganisms, nematodes and seed treatments. Kluwer Academic Press, 412 pp.
Pesticides | Pesticide formulation | [
"Biology",
"Environmental_science"
] | 722 | [
"Biocides",
"Toxicology",
"Pesticides"
] |
17,578,531 | https://en.wikipedia.org/wiki/Aerobic%20granulation | The biological treatment of wastewater in the sewage treatment plant is often accomplished using conventional activated sludge systems. These systems generally require large surface areas for treatment and biomass separation units due to the generally poor settling properties of the sludge. Aerobic granules are a type of sludge that can self-immobilize flocs and microorganisms into spherical and strong compact structures. The advantages of aerobic granular sludge are excellent settleability, high biomass retention, simultaneous nutrient removal and tolerance to toxicity. Recent studies show that aerobic granular sludge treatment could be a potentially good method to treat high strength wastewaters with nutrients, toxic substances.
The aerobic granular sludge usually is cultivated in SBR (sequencing batch reactor) and applied successfully as a wastewater treatment for high strength wastewater, toxic wastewater and domestic wastewater. Compared with conventional aerobic granular processes for COD removal, current research focuses more on simultaneous nutrient removal, particularly COD, phosphorus and nitrogen, under pressure conditions, such as high salinity or thermophilic condition.
In recent years, new technologies have been developed to improve settleability. The use of aerobic granular sludge technology is one of them.
Context
Proponents of aerobic granular sludge technology claim "it will play an important role as an innovative technology alternative to the present activated sludge process in industrial and municipal wastewater treatment in the near future" and that it "can be readily established and profitably used in activated sludge plants". However, in 2011 it was characterised as "not yet established as a large-scale application ... with limited and unpublished full-scale applications for municipal wastewater treatment."
Aerobic granular biomass
The following definition differentiates an aerobic granule from a simple floc with relatively good settling properties and came out of discussions which took place at the 1st IWA-Workshop Aerobic Granular Sludge in Munich (2004):
Formation of aerobic granules
Granular sludge biomass is developed in sequencing batch reactors (SBR) and without carrier materials. These systems fulfil most of the requirements for their formation as:
Feast – Famine regime: short feeding periods must be selected to create feast and famine periods (Beun et al. 1999), characterized by the presence or absence of organic matter in the liquid media, respectively. With this feeding strategy the selection of the appropriate micro-organisms to form granules is achieved. When the substrate concentration in the bulk liquid is high, the granule-former organisms can store the organic matter in form of poly-β-hydroxybutyrate to be consumed in the famine period, giving an advantage over filamentous organisms. When an anaerobic feeding is applied this factor is enhanced, minimising the importance of short settling time and higher hydrodynamic forces.
Short settling time: This hydraulic selection pressure on the microbial community allows the retention granular biomass inside the reactor while flocculent biomass is washed-out. (Qin et al. 2004)
Hydrodynamic shear force : Evidences show that the application of high shear forces favours the formation of aerobic granules and the physical granule integrity. It was found that aerobic granules could be formed only above a threshold shear force value in terms of superficial upflow air velocity above 1.2 cm/s in a column SBR, and more regular, rounder, and more compact aerobic granules were developed at high hydrodynamic shear forces (Tay et al., 2001 ).
Granular activated sludge is also developed in flow-through reactors using the Hybrid Activated Sludge (HYBACS) process, comprising an attached-growth reactor with short retention time upstream of a suspended growth reactor. The attached bacteria in the first reactor, known as a SMART unit, are exposed to a constant high COD, triggering the expression of high concentrations of hydrolytic enzymes in the EPS layer around the bacteria. The accelerated hydrolysis liberates soluble readily-degradable COD which promotes the formation of granular activated sludge.
Advantages
The development of biomass in the form of aerobic granules is being studied for its application in the removal of organic matter, nitrogen and phosphorus compounds from wastewater.
Aerobic granules in an aerobic SBR present several advantages compared to conventional activated sludge process such as:
Stability and flexibility: the SBR system can be adapted to fluctuating conditions with the ability to withstand shock and toxic loadings
Low energy requirements: the aerobic granular sludge process has a higher aeration efficiency due to operation at increased height, while there are neither return sludge or nitrate recycle streams nor mixing and propulsion requirements
Reduced footprint: The increase in biomass concentration that is possible because of the high settling velocity of the aerobic sludge granules and the absence of a final settler result in a significant reduction in the required footprint.
Good biomass retention: higher biomass concentrations inside the reactor can be achieved, and higher substrate loading rates can be treated.
Presence of aerobic and anoxic zones inside the granules: to perform simultaneously different biological processes in the same system (Beun et al. 1999 )
Reduced investment and operational costs: the cost of running a wastewater treatment plant working with aerobic granular sludge can be reduced by at least 20% and space requirements can be reduced by as much as 75% (de Kreuk et al., 2004).
The HYBACS process has the additional benefit of being a flow-through process, thus avoiding the complexities of SBR systems. It is also readily applied to the upgrading of existing flow-through activated sludge processes, by installing the attached growth reactors upstream of the aeration tank. Upgrading to granular activated sludge process enables the capacity of an existing wastewater treatment plant to be doubled.
Treatment of industrial wastewater
Synthetic wastewater was used in most of the works carried out with aerobic granules. These works were mainly focused on the study of granules formation, stability and nutrient removal efficiencies under different operational conditions and their potential use to remove toxic compounds. The potential of this technology to treat industrial wastewater is under study, some of the results:
Arrojo et al. (2004) operated two reactors that were fed with industrial wastewater produced in a laboratory for analysis of dairy products (Total COD : 1500–3000 mg/L; soluble COD: 300–1500 mg/L; total nitrogen: 50–200 mg/L). These authors applied organic and nitrogen loading rates up to 7 g COD/(L·d) and 0.7 g N/(L·d) obtaining removal efficiencies of 80%.
Schwarzenbeck et al. (2004) treated malting wastewater which had a high content of particulate organic matter (0.9 g TSS/L). They found that particles with average diameters lower than 25–50 μm were removed at 80% efficiency, whereas particles bigger than 50 μm were only removed at 40% efficiency. These authors observed that the ability of aerobic granular sludge to remove particulate organic matter from the wastewaters was due to both incorporation into the biofilm matrix and metabolic activity of protozoa population covering the surface of the granules.
Cassidy and Belia (2005) obtained removal efficiencies for COD and P of 98% and for N and VSS over 97% operating a granular reactor fed with slaughterhouse wastewater (Total COD: 7685 mg/L; soluble COD: 5163 mg/L; TKN: 1057 mg/L and VSS: 1520 mg/L). To obtain these high removal percentages, they operated the reactor at a DO saturation level of 40%, which is the optimal value predicted by Beun et al. (2001) for N removal, and with an anaerobic feeding period which helped to maintain the stability of the granules when the DO concentration was limited.
Inizan et al. (2005) treated industrial wastewaters from pharmaceutical industry and observed that the suspended solids in the inlet wastewater were not removed in the reactor.
Tsuneda et al. (2006), when treating wastewater from metal-refinery process (1.0–1.5 g NH4+-N/L and up to 22 g/L of sodium sulphate), removed a nitrogen loading rate of 1.0 kg-N/m3·d with an efficiency of 95% in a system containing autotrophic granules.
Usmani et al. (2008) high superficial air velocity, a relatively short settling time of 5–30 min, a high ratio of height to diameter (H/D=20) of the reactor and optimum organic load facilitates the cultivation of regular compact and circular granules.
Figueroa et al. (2008), treated wastewater from a fish canning industry. Applied OLR were up to 1.72 kg COD/(m3·d) with fully organic matter depletion. Ammonia nitrogen was removed via nitrification-denitrification up to 40% when nitrogen loading rates were of 0.18 kg N/(m3·d). The formation of mature aerobic granules occurred after 75 days of operation with 3.4 mm of diameter, SVI of 30 mL/g VSS and density around 60 g VSS/L-granule
Farooqi et al. (2008), Wastewaters from fossil fuel refining, pharmaceuticals, and pesticides are the main sources of phenolic compounds. Those with more complex structures are often more toxic than the simple phenol. This study was aimed at assessing the efficacy of granular sludge in UASB and SBR for the treatment of mixtures of phenolics compounds. The results indicates that anaerobic treatment by UASB and aerobic treatment by SBR can be successfully used for phenol/cresol mixture, representative of major substrates in chemical and petrochemical wastewater and the results shows proper acclimatization period is essential for the degradation of m – cresol and phenol. Moreover, SBR was found as a better alternative than UASB reactor as it is more efficient and higher concentration of m cresols can be successfully degraded.
López-Palau et al. (2009), treated wastewater from a winery industry. The formation of granules was performed using a synthetic substrate and after 120 days of operation, synthetic media was replaced by real winery wastewater, with a COD loading of 6 kg COD/(m3·d).
Dobbeleers "et al." (2017), treated wastewater from potato industry. Granulation was successful achieved and simultaneous nitrification/denitrification was possible by short cutting the nitrogen cycle.
Caluwé "et al." (2017), Compared an aerobic feast/famine strategy and an anaerobic feast, aerobic famine strategy for the formation of aerobic granular sludge during the treatment of industrial petrochemical wastewater. Both strategies were successful.
Pilot research in aerobic granular sludge
Aerobic granulation technology for the application in wastewater treatment is widely developed at laboratory scales. The large-scale experience is growing rapidly and multiple institutions are making efforts to improve this technology:
Since 1999 Royal HaskoningDHV (former DHV Water), Delft University of technology (TUD), STW (Dutch Foundation for Applied Technology) and STOWA (Dutch Foundation for Applied Water Research) have been cooperating closely on the development of the aerobic granular sludge technology (Nereda). In September 2003, a first extensive pilot plant research was executed at STP Ede, the Netherlands with focus on obtaining stable granulation and biological nutrient removal. Following the positive outcome together with six Dutch Water Boards the parties decided to establish a Public-Private Partnership (PPP)- the National Nereda Research Program (NNOP)- to mature, further scale-up and implement several full-scale units. As part of this PPP extensive pilot tests have been executed between 2003 and 2010 at multiple sewage treatment plants. Currently more than 20 plants are running or under construction across 3 continents.
From the basis of the aerobic granular sludge but using a contention system for the granules, a sequencing batch biofilter granular reactor (SBBGR) with a volume of 3.1m3 was developed by IRSA (Istituto di Ricerca Sulle Acque, Italy). Different studies were carried out in this plant treating sewage at an Italian wastewater treatment plant.
The use of aerobic granules prepared in laboratory, as a starter culture, before adding in main system, is the base of the technology ARGUS (Aerobic granules upgrade system) developed by EcoEngineering Ltd.. The granules are cultivated on-site in small bioreactors called propagators and fill up only 2 to 3% of the main bioreactor or fermentor (digestor) capacity. This system is being used in a pilot plant with a volume of 2.7 m3 located in one Hungarian pharmaceutical industry.
The Group of Environmental Engineering and Bioprocesses from the University of Santiago de Compostela is currently operating a 100 L pilot plant reactor.
The feasibility study showed that the aerobic granular sludge technology seems very promising (de Bruin et al., 2004. Based on total annual costs a GSBR (Granular sludge sequencing batch reactors) with pre-treatment and a GSBR with post-treatment proves to be more attractive than the reference activated sludge alternatives (6–16%).
A sensitivity analysis shows that the GSBR technology is less sensitive to land price and more sensitive to rain water flow. Because of the high allowable volumetric load the footprint of the GSBR variants is only 25% compared to the references. However, the GSBR with only primary treatment cannot meet the present effluent standards for municipal wastewater, mainly because of exceeding the suspended solids effluent standard caused by washout of not well settleable biomass.
Full scale application
Aerobic granulation technology is already successfully applied for treatment of wastewater.
Since 2005, RoyalHaskoningDHV has implemented more than 100 full-scale aerobic granular sludge technology systems (Nereda) for the treatment of both industrial and municipal wastewater across 5 continents. One example is STP Epe, The Netherlands, with a capacity of 59.000 pe and 1,500 m3.h-1, being the first full-scale municipal Nereda in The Netherlands. Examples of the latest Nereda sewage treatment plants (2012–2013) include Wemmershoek- South Africa, Dinxperlo, Vroomshoop, Garmerwolde – The Netherlands.
EcoEngineering applied aerobic granulation process in three pharmaceutical industries, Krka d.d. Novo mesto Slovenia, Lek d.d. Lendava, Slovenia and Gedeon Richter Rt. Dorog, Hungary. Wastewater treatment plants are already running more than five years.
See also
Agricultural wastewater treatment
Effluent guidelines
Industrial wastewater treatment
List of waste water treatment technologies
Sedimentation (water treatment)
Water purification
Sequencing batch reactor
References
General references
Van der Roest H., de Bruin B., van Dalen R., Uijterlinde C. (2012) Maakt Nereda-installatie Epe hooggespannen verwachtingen waar?, Vakblad H2O, nr.23, 2012, p30-p34.
Giesen A., van Loosdrecht M.C.M., Niermans R. (2012) Aerobic granular biomass: the new standard for domestic and industrial wastewater treatment?, Water21, April 2012, p28-p30.
Zilverentant A., de Bruin B., Giesen A. (2011) Nereda: The new Standard for Energy and Cost Effective Industrial and Municipal Wastewater treatment, SKIW, Het National Water Symposium, May 2011.
Water Sewage & Effluent (2010) 'Water Nymph' at Gansbaai, Water Sewage & Effluent, Water Management solutions for Africa, Volume 30 no.2, 2010, p50-p53.
Gao D. Liu L. Liang H. Wu W.M. (2010), Aerobic granular sludge: characterization, mechanism of granulation and application to wastewater treatment, Critical reviews in Biotechnology
Dutch Water Sector (2012), Commissioning Nereda at wwtp Epe: Wonder granule keeps its promise
Kolver (2012), Success at Gansbaai leads to construction of another Nereda plant, engineeringnews
Nadaba (2009), Gansbaai wastewater project incorporates techno innovation , engineeringnews
Euronews (2012), Dutch Investor cleans up water treatment
External links
Royal HaskoningDHV-NEREDA
TUDELFT – Delft University
Aquatic ecology
Environmental engineering
Environmental soil science
Waste treatment technology | Aerobic granulation | [
"Chemistry",
"Engineering",
"Biology",
"Environmental_science"
] | 3,500 | [
"Water treatment",
"Chemical engineering",
"Aquatic ecology",
"Environmental soil science",
"Civil engineering",
"Ecosystems",
"Environmental engineering",
"Waste treatment technology"
] |
17,578,696 | https://en.wikipedia.org/wiki/Marine%20spatial%20planning | Marine spatial planning (MSP) also known interchangeably as Maritime Spatial Planning, is an ocean management instrument which aids policy-makers and stakeholders in compartmentalizing sea basins within state jurisdiction according to social, ecological and economical objectives in order to make informed and coordinated decisions about how to use marine resources sustainably. MSP generally uses maps to create a more comprehensive picture of a marine area – identifying where and how an ocean area is being used and what natural resources and habitat exist. It is similar to land-use planning, but for marine waters.
Through the planning and mapping process of a marine ecosystem, planners can consider the cumulative effect of maritime industries on our seas, seek to make industries more sustainable and proactively minimize conflicts between industries seeking to utilise the same sea area. The intended result of MSP is a more coordinated and sustainable approach to how our oceans are used – ensuring that marine resources and services are utilized, but within clear environmental limits to ensure marine ecosystems remain healthy and biodiversity is conserved.
Definition and concept
The most commonly used definition of marine spatial planning was developed by the Intergovernmental Oceanographic Commission (IOC) of UNESCO:
The main elements of marine spatial planning include an interlinked system of plans, policies and regulations; the components of environmental management systems (e.g. setting objectives, initial assessment, implementation, monitoring, audit and review); and some of the many tools that are already used for land use planning. Whatever the building blocks, the essential consideration is that they need to work across sectors and give a geographic context in which to make decisions about the use of resources, development, conservation and the management of activities in the marine environment
Effective marine spatial planning has essential attributes:
Multi-objective. Marine spatial planning should balance ecological, social, economic, and governance objectives, but the over riding objective should be increased sustainability.
Spatially focused. The ocean area to be managed must be clearly defined, ideally at the ecosystem level - certainly being large enough to incorporate relevant ecosystem processes.
Integrated. The planning process should address the interrelationships and interdependence of each component within the defined management area, including natural processes, activities, and authorities.
The IOC-UNESCO Marine Spatial Planning Programme helps countries implement ecosystem-based management by finding space for biodiversity, conservation and sustainable economic development in marine areas. IOC-UNESCO has developed several guides, including a 10-step guide on how to get a marine spatial plan started: "Step-by-step Approach for Marine Spatial Planning toward Ecosystem-based Management". IOC-UNESCO has also developed a world-wide inventory of MSP activities.
In order for an MSP programme to be successful, there is an crucial need to secure inter- and intra-sectoral cooperations - cooperations between sectors with diverging objectives such as social, ecological and economical - in order to ensure equal fulfillment of all objectives sought to be achieved at sea.
Evaluation of Spatially managed marine areas
To evaluate how well a marine spatial plan performs, the EU FP7 project MESMA (2009–2013) has developed a step-wise evaluation approach. This framework provides guidance on the selection, mapping, and assessment of ecosystem components and human pressures. It also addresses the evaluation of management effectiveness and potential adaptations to management. Moreover, it provides advice on the use of spatially explicit tools for practical tasks like the assessment of cumulative impacts of human pressures or pressure-state relationships. Governance is directly linked to the framework through a governance analysis that can be performed in parallel and feeds into the different steps of the framework. To help managers, MESMA has developed a tools portal.
Tools
There are a number of useful and innovative tools that can help managers implement marine spatial planning. Some include:
USA MarineCadastre.gov
Australia's Marxan Software
SeaSketch, a collaborative geodesign tool for MSP
UCSB's Global Map of Human Impacts to Marine Ecosystems
Duke University's Marine Geospatial Ecology Tools
Center for Ocean Solutions' Collaborative Geospatial Information and Tools
MESMA Tools for monitoring and evaluation of marine spatial planning
Scotland's National Marine Plan Interactive and Marine Scotland Information Portal
Mid-Atlantic Ocean Data Portal
New England's Northeast Ocean Data Portal
Marine Spatial Planning in the European Union
Marine Spatial Planning within the context of the European Union is most often addressed as Maritime Spatial Planning - and thus for the sake of the section, the latter name will be used.
In the European Commission's 2002 Communications Report to the European Parliament called “Towards a Strategy to Protect and Conserve the Marine Environment”, the very first mentioning of the concept Maritime Spatial Planning appears. The report urged for a need to plan sectoral activities within the sea basins in order to measure the environmental impacts and integrate protective measures. These EU-wide statements could have derived inspiration from the 4th conference of Baltic Sea Ministers for Spatial Planning and Development seeking to establish a transnational spatial planning cooperation including the management of marine and coastal areas. Maritime Spatial Planning officially became a central pillar to the European Commission's maritime policies with the publishing of the Integrated Maritime Policy (IMP) in October 2007. The following year, 2008, the European Commission introduced another marine focused document called a Roadmap for Maritime Spatial Planning: Achieving Common Principles – and in 2012 further development took place when the Commission adopted a Communication on Blue Growth: Opportunities for marine and maritime sustainable growth aiming to unlock the potentials of the blue economy. After more than a decade of MSP programs within the EU, it was decided to pass an EU-wide legislation on the matter in 2014, introducing the Maritime Spatial Planning Directive (2014/89/EU). MSP is presented as a vital environmental protection instrument of the IMP, as one of the central aims are to secure Good Environmental Status (GES) which involves the conservation of clean, healthy and productive seas.
The Maritime Spatial Planning Directive
According to the European Commission the MSP Directive serves as a framework to organize the many sectoral activities and industries taking place in the sea basins surrounding the European Union, such as fishing, aquaculture, nature conservation, shipping and renewable energy installations. The main objectives of the Directive are to reduce conflicts and increase border cooperation among member states with regards to improving efficient utilization of the sea basins, encourage investments and ensuring proper protection of the marine environment.
The MSP Directive introduced requirements for Member States to establish their own maritime spatial planning strategies and implement these by 2021 - especially targeting the 22 coastal Member States.
In the context of the European Union, we can identify four central policy drivers for the implementation of Maritime Spatial Planning: environmental legislation, legislation for renewable energy, fisheries regulation and frameworks for cross-sectoral and integrated management.
MSP in the EU’s marine renewable energy sector
As MSP merely is an instrument aiming to organize sectoral activities in sea bassins, a look into the renewable sector can give an understanding of the workings of MSP.
The European Commission highlights that the MSP Directive alongside the aims outlined in the Biodiversity Strategy is the primary legal framework for the achievement of the new marine renewable energy objectives within the European Union.
As the EU is pioneering in offshore wind energy, and is the world's leading actor in the development of marine renewable energy as well as possesses the world's largest installment of renewable energy sources, MSP poses a promising role for the development of marine renewable energy, as it can streamline licensing and installations, reduce conflicts among maritime users as well as increase legal security for stakeholders
Challenges of MSP in the case of EU’s marine renewable energy
While MSP Directive has the potential to simplify the balancing of renewable energy and protection of nature, as it allows actors to divide the sea basins into space with different usages, the MSP Directive itself does have its weaknesses and thus cannot stand alone. The MSP Directive requires all coastal states to work out maritime spatial policies by 2021, however much discretion is left with the member states. The current EU legislation on the protection of nature, species and habitats, such as the Habitats and Birds Directives and the Water Framework Directive, possess derogation clauses, however there are no obligations for member states to actually apply these and thus balance out the creation of marine energy sources and protection of nature (van Hees 2021: 28–31). It is largely recommended that the spatial choices feed into the nature preserving Directives such as the Habitats and Birds Directives and the Water Framework Directive
The cumulative effects of offshore renewable energy are uncertain, as Cumulative Impact Assessments (CIA), Strategic Environmental Assessment (SEA), and Environmental Impact Assessment (EIA) often are implemented independently, why they to a large extend fail to paint a full picture of the negative impacts. The EU's MSP is criticized in this regard because when results of these assessments proves inconclusive the MSP Directive lays down the precautionary principle however without giving specification other than member states are to take “preventative measures”. The usage of EIA is further criticized due to it lack of abilities to create assessments for tidal and wave energy installments. The ability to tackle the potential impacts of marine renewable energy sources such as tidal stream, wave energy and salinity gradient energy is a great concern due to uncertaint and the potential risks of sandbank erosions, underwater noise pollution from constructions, sediment starvation, industrial heat waste and physical damage to travelling species as well as aquatic environments. However, evidence show that small-scale energy project has fewer prospects of grave environmental implications, and main concerns lies with projets of large-scales.
A central challenge to the MSP within the European Union is the lack of standardized data collection and integration across databases. Therefore, improving this area of concern could help paint a greater picture of the environmental impacts and statuses across Member States’ shared sea basins.
To further develop and strengthen MSP with the European Union, it is vital to improve informed policy-making on the area of ocean management. Developing quantitative and comprehensive environmental sustainability assessment (QCESA) tools under the Sustainable Marine Ecosystem Services (SUMES) projects, allows for an integration of Life Cycle Assessments (LCA) and Ecosystem Service Assessments (ESA), potentially simplifying decision-making process among policy makers, as QCESA highlight the trade-offs between various sectoral activities.
MSP and marine renewable energy in EU-Member States
A majority of research conducted on MSP activities are case studies of each Member State as much discretion is left with the Member States, meaning that MSP varies a great deal across the EU.
Belgium and the Netherlands can be seen as some of the frontrunners i MSP, as they both implemented own MSP strategies before EU-wide obligations to do so. From 2002 to 2005 the Belgian GAURFE project sought to deal with the use of the North Sea, and the project defined spatial scenarios clearly visualizing possibilities for the sea territory. Similarly in the Netherlands in 2005 the country's ministry on Housing, Spatial Planning and Environment published its first marine chapter in their national Spatial Planning Document, promoting efficient uses of marine spaces and drawing areas for shipping, military uses and ecologically valued areas. In 2013 Dutch ministries initiated a discussion on marine visions for the North Sea by 2050 involving cultivating the ecosystems whilst utilizing the waves and current to generate more renewable energy. In order to achieve such vision the North Sea 2030 Strategy was initiated. The Netherlands also presents an interesting challenge that smaller coastal Member States can face, as a smaller coastal line simply means less maritime space to delegate, which results in stricter MSP policies at risk for deprioritizing conservation of marine environment in order to achieve economic goals.
In 2009 France developed National Strategy for the Oceans, welcoming the emerging focus on blue economy and further elaborated on this approach in 2016 with an alteration of the national Environmental Code, officially implementing the concept of MSP. The tools for implementing MSP are given in the national document of the Sea Basin Strategies. In France, MSP practices currently focus on strengthening the concept of participation as listed in art. 9 and 10 of the MSP Directive (2014/89/EU).
Unlike the above-mentioned Member States, Spain has no overarching national maritime policy, however the country has set down sector-specific legislations clearly stating the management of marine spaces. Currently there are 72 areas which have undergone the Strategic Environmental Assessment (SEA), and been classified as suitable for wind farm installations with the ability to be restricted based on the environmental impacts of the installations (Garcia et al. 2021: 2–3). Strengthening Marine Spatial Planning (MSP) in Spain could elevate the importance of maritime zones on the national agenda, as demonstrated by countries like the Netherlands and Belgium, where a unified, long-term vision has supported effective marine area planning.
Marine spatial planning in the United Kingdom
The Marine and Coastal Access Act 2009 defined arrangements for a new system of marine management, including the introduction of marine spatial planning, across the UK. Although the new system comprises the principles of marine spatial planning as articulated by the European Commission, it is commonly referred to in the UK simply as 'marine planning'.
Among the government's stated aims for the new marine planning system is to ensure that coastal areas, the activities within them and the problems they face are managed in an integrated and holistic way. This will require close interaction with town and country planning regimes and, in England and Wales, the new regime for nationally significant infrastructure projects (NSIPs) in key sectors, such as energy and transport.
The Marine Policy Statement
The cornerstone of the UK marine planning system is the Marine Policy Statement (MPS). It sets out the sectoral/activity specific policy objectives that the UK Government, Scottish Government, Welsh Assembly Government and Northern Ireland Executive are seeking to achieve in the marine area in securing the UK vision of 'clean, healthy, safe, productive and biologically diverse oceans and seas.'
The MPS is the framework for preparing Marine Plans and taking decisions that affect the marine environment in England, Scotland, Wales and Northern Ireland. It will also set the direction for new marine licensing and other authorisation systems in each administration. It is proposed that the draft MPS, which was subject to consultation in 2010, will be formally adopted as Government policy in 2011.
The Marine Management Organisation
In England, the new arrangements provide for the creation of the Marine Management Organisation (MMO), which started work in April 2010. The MMO will deliver UK marine policy objectives for English waters through a series of statutory Marine Plans and other measures. The first Marine Plans will start to be prepared by the MMO on adoption of the MPS in 2011. The UK Government's Consultation on a marine planning system for England document provides, for the benefit of the MMO and other interested parties, more detail on the scope, structure, content and process envisaged for each Marine Plan.
Marine Scotland (Scottish Government)
Marine Scotland is the government authority which will implement marine planning in Scottish waters under the Marine (Scotland) Act. A pre-consultation National Marine Plan was prepared in 2011 and the final Plan was released in March 2015
Marine spatial planning in the United States
On June 12, 2009, President Obama created an Interagency Ocean Policy Task Force to provide recommendations on ocean policy, including MSP.
Some individual states have already undertaken MSP initiatives:
Massachusetts
The Massachusetts Ocean Act, enacted in May 2008, requires the secretary of the Massachusetts Office of Energy and Environmental Affairs to develop a comprehensive ocean management plan. The plan will be submitted to NOAA for incorporation into the existing coastal zone management plan and enforced through the state's regulatory and permitting processes, including the Massachusetts Environmental Policy Act (MEPA) and Chapter 91, the state's waterways law.
The goal is to institute a comprehensive approach to ocean resource management that supports ecosystem health and economic vitality, balances current ocean uses, and considers future needs. This will be accomplished by determining where specific ocean uses will be permitted and which ocean uses are compatible.
Rhode Island
The Rhode Island Ocean Special Area Management Plan, or Ocean SAMP, serves as a federally recognized coastal management and regulatory tool. It was adopted by the Coastal Resource Management Council (CRMC),the state's coastal management agency on October 19, 2010. The Ocean SAMP was then adopted by the National Oceanic and Atmospheric Administration (NOAA) on May 11, 2011. Using the best available science, the Ocean SAMP provides a balanced approach to the development and protection of Rhode Island's ocean-based resources.
Research projects undertaken by University of Rhode Island (URI) scientists provide the essential scientific basis for Ocean SAMP policy development. The Ocean SAMP document underwent an extensive public review process prior to adoption.
California
In 1999, the California state legislature adopted the Marine Life Protection Act. This action required the state to evaluate and possibly redesign all existing state marine protected areas and to potentially create new protected areas that could, to the greatest degree possible, act as a networked system. (Marine protected area designations in California include state marine reserves, marine parks, and marine conservation areas.) This effort does not meet the full definition of marine spatial planning since its goal was to cite only protected areas, rather than all potential ocean uses, but many of its elements (such as stakeholder involvement and mapping approaches) will be of interest to marine spatial planners.
Oregon
Two controversial ocean issues led to a marine spatial planning effort: concern by fishermen over the designation of marine reserves off the Oregon coast, and proposals by industry to site wave energy facilities in Oregon ocean waters.
An executive order directed the Oregon Department of Land Conservation and Development to work with stakeholders and scientists to prepare a plan for ocean energy development (also known as wave energy). This plan was then to be adopted as part of the Oregon Territorial Sea Plan.
The state has appointed an advisory committee and expects to adopt the plan in early 2010. It will include mandatory policies for state and federal agency decisions with regard to locating ocean energy facilities in the Oregon Territorial Sea.
Washington
In March 2010, the Washington State Legislature enacted the Marine Waters Planning and Management Act to address resource use conflicts. A report to the legislature providing guidance and recommendations for moving forward was produced in 2011, and based on the 2012 report, the legislature authorized funds to begin the MSP process off Washington's coast.
A state law required an interagency team to provide recommendations to the Washington State Legislature about how to effectively use Marine Spatial Planning and integrate MSP into existing state management plans and authorities. The team is chaired by the Governor's office and coordinated by the Department of Ecology. Other members include the Washington Department of Natural Resources, Washington Sea Grant, the Washington Department of Fish and Wildlife, and Washington State Parks and Recreation Commission.
See also
Land use planning
Marine Park
Marine Protected Area
Zoning
References
Further reading
ABPmer (2005), Marine Spatial Planning Pilot Literature Review Peterborough.
Online:http://www.abpmer.net/mspp
ABPmer (2006), Marine Spatial Planning Pilot Final Report. Peterborough.
Online:http://www.abpmer.net/mspp
Joint Marine Programme Marine Update 55 (2007): Marine Spatial Planning: A down to earth view of managing activities in the marine environment for the benefit of humans and wildlife
Long R. (2007). Marine Resource Law. Dublin: Thompson Round Hall
Gubbay S. (2004). Marine protected areas in the context of marine spatial planning—discussing the links. A report for WWF-UK Online: https://web.archive.org/web/20070106114002/http://www.wwf.org.uk/filelibrary/pdf/MPAs-marinespacialplanning.pdf
External links and references
UNESCO International Ocean Council MSP Guide
NOAA's MSP Information Site
Marine Spatial Planning from Plymouth Marine Institute
White House Memorandum creating Interagency Ocean Policy Task Force
MESMA Toolbox for monitoring and evaluation of marine spatial planning
Oceanography | Marine spatial planning | [
"Physics",
"Environmental_science"
] | 4,044 | [
"Oceanography",
"Hydrology",
"Applied and interdisciplinary physics"
] |
17,579,850 | https://en.wikipedia.org/wiki/Covering%20code | In coding theory, a covering code is a set of elements (called codewords) in a space, with the property that every element of the space is within a fixed distance of some codeword.
Definition
Let , , be integers.
A code over an alphabet Q of size |Q| = q is called
q-ary R-covering code of length n
if for every word there is a codeword
such that the Hamming distance .
In other words, the spheres (or balls or rook-domains) of radius R
with respect to the Hamming metric around the codewords of C have to exhaust
the finite metric space .
The covering radius of a code C is the smallest R such that C is R-covering.
Every perfect code is a covering code of minimal size.
Example
C = {0134,0223,1402,1431,1444,2123,2234,3002,3310,4010,4341} is a 5-ary 2-covering code of length 4.
Covering problem
The determination of the minimal size of a q-ary R-covering code of length n is a very hard problem. In many cases, only upper and lower bounds are known with a large gap between them.
Every construction of a covering code gives an upper bound on Kq(n, R).
Lower bounds include the sphere covering bound and
Rodemich's bounds and .
The covering problem is closely related to the packing problem in , i.e. the determination of the maximal size of a q-ary e-error correcting code of length n.
Football pools problem
A particular case is the football pools problem, based on football pool betting, where the aim is to come up with a betting system over n football matches that, regardless of the outcome, has at most R 'misses'. Thus, for n matches with at most one 'miss', a ternary covering, K3(n,1), is sought.
If then 3n-k are needed, so for n = 4, k = 2, 9 are needed; for n = 13, k = 3, 59049 are needed. The best bounds known as of 2011 are
Applications
The standard work on covering codes lists the following applications.
Compression with distortion
Data compression
Decoding errors and erasures
Broadcasting in interconnection networks
Football pools
Write-once memories
Berlekamp-Gale game
Speech coding
Cellular telecommunications
Subset sums and Cayley graphs
References
External links
Literature on covering codes
Bounds on
Coding theory | Covering code | [
"Mathematics"
] | 515 | [
"Discrete mathematics",
"Coding theory"
] |
17,580,393 | https://en.wikipedia.org/wiki/Quantum%20dissipation | Quantum dissipation is the branch of physics that studies the quantum analogues of the process of irreversible loss of energy observed at the classical level. Its main purpose is to derive the laws of classical dissipation from the framework of quantum mechanics. It shares many features with the subjects of quantum decoherence and quantum theory of measurement.
Models
The typical approach to describe dissipation is to split the total system in two parts: the quantum system where dissipation occurs, and a so-called environment or bath into which the energy of the former will flow. The way both systems are coupled depends on the details of the microscopic model, and hence, the description of the bath. To include an irreversible flow of energy (i.e., to avoid Poincaré recurrences in which the energy eventually flows back to the system), requires that the bath contain an infinite number of degrees of freedom. Notice that by virtue of the principle of universality, it is expected that the particular description of the bath will not affect the essential features of the dissipative process, as far as the model contains the minimal ingredients to provide the effect.
The simplest way to model the bath was proposed by Feynman and Vernon in a seminal paper from 1963. In this description the bath is a sum of an infinite number of harmonic oscillators, that in quantum mechanics represents a set of free bosonic particles.
Caldeira–Leggett or harmonic bath model
In 1981, Amir Caldeira and Anthony J. Leggett proposed a simple model to study in detail the way dissipation arises from a quantum point of view. It describes a quantum particle in one dimension coupled to a bath. The Hamiltonian reads:
,
The first two terms correspond to the Hamiltonian of a quantum particle of mass and momentum , in a potential at position . The third term describes the bath as an infinite sum of harmonic oscillators with masses and momentum , at positions . are the frequencies of the harmonic oscillators. The next term describes the way that the system and bath are coupled. In the Caldeira–Leggett model, the bath is coupled to the position of the particle. are coefficients which depend on the details of the coupling. The last term is a counter-term which must be included to ensure that dissipation is homogeneous in all space. As the bath couples to the position, if this term is not included the model is not translationally invariant, in the sense that the coupling is different wherever the quantum particle is located. This gives rise to an unphysical renormalization of the potential, which can be shown to be suppressed by employing real potentials.
To provide a good description of the dissipation mechanism, a relevant quantity is the bath spectral function, defined as follows:
The bath spectral function provides a constraint in the choice of the coefficients . When this function has the form , the corresponding classical kind of dissipation can be shown to be Ohmic. A more generic form is
. In this case, if the dissipation is called "super-ohmic", while if is sub-ohmic. An example of a super-ohmic bath is the electro-magnetic field under certain circumstances.
As mentioned, the main idea in the field of quantum dissipation is to explain the way classical dissipation can be described from a quantum mechanics point of view. To get the classical limit of the Caldeira–Leggett model, the bath must be integrated out (or traced out), which can be understood as taking the average over all the possible realizations of the bath and studying the effective dynamics of the quantum system. As a second step, the limit must be taken to recover classical mechanics. To proceed with those technical steps mathematically, the path integral description of quantum mechanics is usually employed. The resulting classical equations of motion are:
where:
is a kernel which characterizes the effective force that affects the motion of the particle in the presence of dissipation. For so-called Markovian baths, which do not keep memory of the interaction with the system, and for Ohmic dissipation, the equations of motion simplify to the classical equations of motion of a particle with friction:
Hence, one can see how Caldeira–Leggett model fulfills the goal of getting classical dissipation from the quantum mechanics framework. The Caldeira–Leggett model has been used to study quantum dissipation problems since its introduction in 1981, being extensively used as well in the field of quantum decoherence.
Dissipative two-level system
The dissipative two-level system is a particular realization of the Caldeira–Leggett model that deserves special attention due to its interest in the field of quantum computation. The aim of the model is to study the effects of dissipation in the dynamics of a particle that can hop between two different positions rather than a continuous degree of freedom. This reduced Hilbert space allows the problem to be described in terms of -spin operators. This is sometimes referred in the literature as the spin-boson model, and it is closely related to the Jaynes–Cummings model.
The Hamiltonian for the dissipative two-level system reads:
,
where and are the Pauli matrices and is the amplitude of hopping between the two possible positions. Notice that in this model the counter-term is no longer needed, as the coupling to gives already homogeneous dissipation.
The model has many applications. In quantum dissipation, it is used as a simple model to study the dynamics of a dissipative particle confined in a double-well potential. In the context of quantum computation, it represents a qubit coupled to an environment, which can produce decoherence. In the study of amorphous solids, it provides the basis of the standard theory to describe their thermodynamic properties.
The dissipative two-level system represents also a paradigm in the study of quantum phase transitions. For a critical value of the coupling to the bath it shows a phase transition from a regime in which the particle is delocalized among the two positions to another in which it is localized in only one of them. The transition is of Kosterlitz–Thouless kind, as can be seen by deriving the renormalization group flow equations for the hopping term.
Energy dissipation in Hamiltonian formalism
A different approach to describe energy dissipation is to consider time dependent Hamiltonians. Against a common misunderstanding, the resulting unitary dynamics can describe energy dissipation, as certain degrees of freedom loose energy and others gain energy. However, the quantum mechanical state of the system stays pure, thus such an approach can not describe dephasing unless a subsystem is chosen and the reduced density matrix of this open quantum system is analyzed. Dephasing leads to quantum decoherence or information dissipation and is often important when describing open quantum systems. However, this approach is typically used e.g. in the description of optical experiments. There a light pulse (described by a time dependent semi-classical Hamiltonian) can change the energy in the system by stimulated absorption or emission.
See also
Dissipation model for extended environment
Jaynes–Cummings model
Open quantum system
Lindblad equation
Quantum decoherence
Dephasing
References
Sources
U. Weiss, Quantum Dissipative Systems (1992), World Scientific.
P. Hänggi and G.L. Ingold, Fundamental Aspects of quantum Brownian motion, Chaos, vol. 15, ARTN 026105 (2005); http://www.physik.uni-augsburg.de/theo1/hanggi/Papers/378.pdf
External links
Visualizing Quantum Dynamics: The Spin-Boson Hamiltonian , Jared Ostmeyer and Julio Gea-Banacloche, University of Arkansas.
Visualizing Quantum Dynamics: The Jaynes-Cummings Model , Jared Ostmeyer and Julio Gea-Banacloche, University of Arkansas.
Condensed matter physics
Statistical mechanics
Quantum mechanics | Quantum dissipation | [
"Physics",
"Chemistry",
"Materials_science",
"Engineering"
] | 1,683 | [
"Theoretical physics",
"Phases of matter",
"Quantum mechanics",
"Materials science",
"Condensed matter physics",
"Statistical mechanics",
"Matter"
] |
17,580,754 | https://en.wikipedia.org/wiki/Gospel%20harmony | A gospel harmony is an attempt to compile the canonical gospels of the Christian New Testament into a single account. This may take the form either of a single, merged narrative, or a tabular format with one column for each gospel, technically known as a synopsis, although the word harmony is often used for both.
Harmonies are constructed for a variety of purposes: to create a readable and accessible piece of literature for the general public, to establish a scholarly chronology of events in the life of Jesus as depicted in the canonical gospels, or to better understand how the accounts relate to each other.
Among academics, the construction of harmonies has been favoured by conservative scholars, though one scholar, B. S. Childs, opposes this. Students of higher criticism see the divergences between the gospel accounts as reflecting the construction of traditions by the early Christian communities. Among modern academics, attempts to construct a single story have largely been abandoned in favour of laying out the accounts in parallel columns for comparison, to allow critical study of the differences between them.
The earliest known harmony is the Diatessaron by Tatian in the 2nd century and variations based on the Diatessaron continued to appear in the Middle Ages. The 16th century witnessed a major increase in the introduction of gospel harmonies and the parallel column structure became widespread. At this time visual representations also started appearing, depicting the life of Christ in terms of a "pictorial gospel harmony", and the trend continued into the 19th–20th centuries.
Overview
A gospel harmony is an attempt to collate the Christian canonical gospels into a single account. Harmonies are constructed by some writers in order to make the gospel story available to a wider audience, both religious and secular. Harmonies can be studied by scholars to establish a coherent chronology of the events depicted in the four canonical gospels in the life of Jesus, to better understand how the accounts relate to each other, and to critically evaluate their differences.
The terms harmony and synopsis have been used to refer to several different approaches to consolidating the canonical gospels. Technically, a "harmony" weaves together sections of scripture into a single narrative, merging the four gospels. There are four main types of harmony: radical, synthetic, sequential and parallel. By contrast, a "synopsis", much like a parallel harmony, juxtaposes similar texts or accounts in parallel format, synchronized by time, while preserving their individual identity, usually in columns. Harmonies may also take a visual form and be undertaken to create narratives for artistic purposes, as in the creation of picture compositions depicting the life of Christ.
The oldest approach to harmonizing consists of merging the stories into a single narrative, producing a text longer than any individual gospel. This creates the most straightforward and detailed account, and one that is likely to be most accessible to non-academic users, such as lay churchgoers or people who are reading the gospels as a work of literature or philosophy.
There are, however, difficulties in the creation of a consolidated narrative. As John Barton points out, it is impossible to construct a single account from the four gospels without changing at least some parts of the individual accounts.
One challenge with any form of harmonizing is that events are sometimes described in a different order in different accounts – the Synoptic Gospels, for instance, describe Jesus overturning tables in the Temple at Jerusalem in the last week of his life, whereas the Gospel of John records a counterpart event only towards the beginning of Jesus's ministry. Harmonists must either choose which time they think is correct, or conclude that separate events are described. Lutheran theologian Andreas Osiander, for instance, proposed in Harmonia evangelica (1537) that Jesus must have been crowned with thorns twice, and that there were three separate episodes of cleansing of the Temple. On the other hand, commentators have long noted that the individual gospels are not written in a rigorously chronological format. This means that an event can be described as falling at two different times and still be the same event, so that the substantive details can be properly brought together in a harmony, although the harmonist will still have the task of deciding which of the two times is more probable.
A less common but more serious difficulty arises if the gospels diverge in their substantive description of an event. An example is the incident involving the centurion whose servant is healed at a distance. In the Gospel of Matthew the centurion comes to Jesus in person; in the Luke version he sends Jewish elders. Since these accounts are clearly describing the same event, the harmonist must decide which is the more accurate description or else devise a composite account.
The modern academic view, based on the broadly accepted principle that Matthew and Luke were written using Mark as a source, seeks to explain the differences between the texts in terms of this process of composition. For example, Mark describes John the Baptist as preaching the forgiveness of sins, a detail which is dropped by Matthew, perhaps in the belief that the forgiveness of sins was exclusive to Jesus.
The modern popularizing view, on the other hand, while acknowledging these difficulties, deemphasizes their importance. This view suggests that the divergences in the gospels are a relatively small part of the whole, and that the accounts show a great deal of overall similarity. The divergences can therefore be sufficiently discussed in footnote in the course of a consolidated narrative, and need not stand in the way of conveying a better overall view of the life of Jesus or of making this material more accessible to a wider readership.
To illustrate the concept of parallel harmony, a simple example of a "synopsis fragment" is shown here, consisting of just four episodes from the Passion. A more comprehensive parallel harmony appears in a section below.
Early Church and Middle Ages
Tatian's influential Diatessaron, which dates to about AD 160, was perhaps the first harmony. The Diatessaron reduced the number of verses in the four gospels from 3,780 to 2,769 without missing any event of teaching in the life of Jesus from any of the gospels. Some scholars believe Tatian may have drawn on one or more noncanonical gospels. The Gospel of the Ebionites, composed about the same time, is believed to have been a gospel harmony.
Variations based on the Diatessaron continued to appear in the Middle Ages. For example, the Codex Sangallensis (based on the 6th century Codex Fuldensis) dates to 830 and has a Latin column based on the Vulgate and an Old High German column that often resembles the Diatessaron, although errors frequently appear within it. The Liege harmony in the Limburg dialect (Liege University library item 437) is a key Western source of the Diatessaron and dates to 1280, although it was published much later. The two extant recensions of the Diatessaron in Medieval Italian are the single manuscript Venetian from the 13th or 14th century and the 26 manuscript Tuscan from the 14th–15th century.
In the 3rd century Ammonius of Alexandria developed the forerunner of modern synopsis (perhaps based on the Diatessaron) as the Ammonian Sections in which he started with the text of Matthew and copied along parallel events. There are no extant copies of the harmony of Ammonius and it is only known from a single reference in the letter from Eusebius to Carpianus. In the letter Eusebius also discusses his own approach, i.e. the Eusebian Canons in which the texts of the gospels are shown in parallel to help comparison among the four gospels.
In the 5th century, Augustine of Hippo wrote extensively on the subject in his book Harmony of the Gospels. Augustine viewed the variations in the gospel accounts in terms of the different focuses of the authors on Jesus: Matthew on royalty, Mark on humanity, Luke on priesthood and John on divinity.
Clement of Llanthony's Unum ex Quatuor (One from Four) was considered an improvement on previous gospel harmonies, although modern scholars sometimes opine that no major advances beyond Augustine emerged on the topic until the 15th century. Throughout the Middle Ages harmonies based on the principles of the Diatessaron continued to appear, e.g., the Liege harmony by Plooij in Middle Dutch, and the Pepysian harmony in Middle English. The Pepysian harmony (Magdalene college, Cambridge, item Pepys 2498) dates to about 1400 and its name derives from having been owned by Samuel Pepys.
15th–20th centuries
In the 15th and the 16th centuries some new approaches to harmony began to appear. For example, Jean Gerson produced a harmony in 1420 which gave priority to the Gospel of John. Cornelius Jansen also published his harmony in 1549, focusing on the four gospels and even referring to the Acts of the Apostles. On the other hand John Calvin's approach focused on the three synoptic Gospels, and excluded the Gospel of John.
By this time visual representations had also started appearing, for instance, the 15th-century artist Lieven de Witte produced a set of about 200 woodcut images that depicted the Life of Christ in terms of a "pictorial gospel harmony" which then appeared in Willem van Branteghem's harmony published in Antwerp in 1537. The importance of imagery is reflected in the title of Branteghem's well known work: The Life of Jesus Christ Skillfully Portrayed in Elegant Pictures Drawn from the Narratives of the Four Evangelists
The 16th century witnessed a major increase in the introduction of gospel harmonies. In this period the parallel column structure became widespread, partly in response to the rise of biblical criticism. This new format was used to emphasize the trustworthiness of the gospels. It is not clear who produced the first parallel harmony, but Gerardus Mercator's 1569 system is a well-known example. In terms of content and quality, Johann Jakob Griesbach's 1776 synopsis was a notable case.
At the same time, the rise of modern biblical criticism was instrumental in the decline of the traditional apologetic gospel harmony. The Enlightenment writer, Gotthold Ephraim Lessing, observed:
W. G. Rushbrooke's 1880 Synopticon is at times considered a turning point in the history of the synopsis, as it was based on Marcan priority, i.e. the assumption that the Gospel of Mark was the first to be written. Thirteen years later, John Albert Broadus used historical accounts to assign priorities in his harmony, while previous approaches had used feasts as the major milestones for dividing the life of Christ.
Towards the end of the 19th century, after extensive travels and study in the Middle East, James Tissot produced a set of 350 watercolors which depicted the life of Christ as a visual gospel harmony. Tissot synthesized the four gospels into a singular narrative with five chapters: "the Holy Childhood, the Ministry, Holy Week, the Passion, and the Resurrection". He also made portraits of each of the Four Evangelists to honor them.
In the 20th century, the Synopsis of the Four Gospels by Kurt Aland came to be seen by some as "perhaps the standard for an in-depth study of the Gospels." A key feature of Aland's work is the incorporation of the full text of the Gospel of John. Bernard Orchard's synopsis (which has the same title) was of note in that it took the unusual approach of abandoning Marcan priority and assuming the synoptic gospels were written with Matthean priority and Markan posteriority.
An example parallel harmony
The following table is an example of a parallel harmony. The order of events, especially during the ministry period, has been the subject of speculation and scholarly debate. The order below is based on those of Anglican William Newcome in 1778 and Baptists Steven L. Cox and Kendell H. Easley in 2006.
See also
Little Gidding harmonies
Jefferson Bible, created by Thomas Jefferson
The Gospel in Brief, created by Leo Tolstoy
Palmarian Bible
Ministry of Jesus
Chronology of the Bible
References
Citations
Bibliography
This article incorporates work from A Harmony of the Gospels in Greek by Edward Robinson, a publication now in the public domain.
Further reading
Thomson, Charles, A Synopsis of the Four Evangelists (1815)
Robinson, Edward, Greek Harmony of the Gospels (1845; second edition, 1851)
Robinson, Edward, English Harmony of the Gospels (1846)
Orville Daniel, A Harmony of the Four Gospels, 2nd Ed, Baker Books Pub, 1996.
R. Thomas & S. Gundry, The NIV Harmony of the Gospels, HarperCollins Pub, 1988.
External links
Augustine's Harmony of the Gospels
Parallel Gospels in Harmony Online version of Parallel Gospels in Harmony: with Study Guide, by David A. Reed, a public domain book
1st-century Christianity
Chronology
Gospels
Canonical Gospels
Christian terminology | Gospel harmony | [
"Physics"
] | 2,618 | [
"Spacetime",
"Chronology",
"Physical quantities",
"Time"
] |
17,580,808 | https://en.wikipedia.org/wiki/List%20of%20oceanographic%20institutions%20and%20programs | This is a list of oceanography institutions and programs worldwide. Oceanographic institutions and programs are broadly defined as places where scientific research is carried out relating to oceanography. This list is organized geographically. Some oceanographic institutions are standalone programs, such as non-governmental organizations or government-funded agencies. Other oceanographic institutions are departments within colleges and universities. While oceanographic research happens at many other departments at other colleges and universities, such as Biology and Geology departments, this list focuses on larger departments and large research centers specifically devoted to oceanography and marine science. Aquaria are not listed here.
International
International oceanographic programs
Intergovernmental Oceanographic Commission, UNESCO
International Council for the Exploration of the Sea, (ICES)
International Hydrographic Organization
International Ocean Discovery Program, formerly called the Integrated Ocean Drilling Program.
InterRidge, an international research collaboration on oceanic seafloor spreading zones.
Mediterranean Science Commission, (CIESM)
North Pacific Marine Science Organization (PICES)
Scientific Committee on Oceanic Research, part of the International Science Council.
Societies and professional affiliations
American Geophysical Union
Association for the Sciences of Limnology and Oceanography
Coastal and Estuarine Research Federation
European Geosciences Union
The Oceanography Society
Institutions by country
Australia
Australian Institute of Marine Science, Queensland
Australian Marine Sciences Association, the professional body for marine scientists
Australian Meteorological and Oceanographic Society, a scholarly society
Commonwealth Scientific and Industrial Research Organisation, Canberra
Institute for Marine and Antarctic Studies, Hobart, Tasmania
Sydney Institute of Marine Science
University of New South Wales, Sydney
Bangladesh
Bangabandhu Sheikh Mujibur Rahman Maritime University, Dhaka. BSMRMU
Bangladesh Oceanographic Research Institute, Ramu, Cox's Bazar. BORI
Institute of Marine Sciences, University of Chittagong was the country's first marine research institution, inaugurated in 1971.
University of Chittagong, Chittagong-4331, Chattogram. of Oceanography
Patuakhali Science and Technology University, Dumki-8602, Patuakhali. Department of Marine Fisheries and Oceanography (MFO)
Shahjalal University of Science & Technology, Sylhet. Department of Oceanography
Sylhet Agricultural University, Sylhet-3100. Department of Coastal and Marine Fisheries
University of Dhaka, Department of Oceanography
Belgium
European Global Ocean Observing System, Brussels.
European Marine Board, an international organization based in Oostende, Belgium. European Marine Board
Flanders Marine Institute, Oostende. VLIZ
University of Liège, Interfacultary Center for Marine Research MARE
Belize
Wee Wee Caye Marine Lab on an island off the coast of Stann Creek District.
Bermuda
Bermuda Institute of Ocean Sciences, an independent science and education institute in Ferry Reach, St. Georges. BIOS
Brazil
Brazilian national programs:
Admiral Paulo Moreira Institute for Marine Studies in Arraial do Cabo, Rio de Janeiro is associated with the Brazilian Navy. IEAPM
National Institute for Oceanographic and Waterway Research. INPOH
National Institute for Space Research in São Paulo conducts ocean remote sensing research. INPE
Brazilian universities with oceanography departments or institutes:
Centro Universitário Monte Serrat. Oceanografia, UNIMONTE
Center for Marine Studies in Pontal do Paraná, associated with the Federal University of Paraná.
Fundação Universidade Federal do Rio Grande. FURG
Oceanographic Institute of the University of São Paulo. USP
Universidade do Vale do Itajaí. UNIVALI Oceanography
Universidade do Estado do Rio de Janeiro. Faculdade de Oceanografia, UERJ
Universidade Federal da Bahia. Curso de Graduação em Oceanografia, UFBA
Universidade Federal de São Paulo. Departamento de Ciências do Mar, UNIFESP
Universidade Federal de Santa Catarina. UFSC
Universidade Federal do Ceará. UFC
Universidade Federal do Espírito Santo. Oceanografia na UFES
Universidade Federal do Maranhão. UFMA
Universidade Federal do Pará. UFPA
Universidade Federal do Paraná. UFPR
Universidade Federal do Pernambuco. UFPE
Bulgaria
Agricultural Academy Institute of Fish Resources in Varna. Institute of Fish Resources
Bulgarian Academy of Sciences in Varna. Institute of Oceanology
Cameroon
National Oceanographic Data Centre of Cameroon. NODC
Canada
Bamfield Marine Sciences Centre, a marine research station in Barkley Sound, British Columbia associated with several nearby universities. Bamfield MSC
Bedford Institute of Oceanography, a governmental research facility in Dartmouth, Nova Scotia. BIO
Bellairs Research Institute in Barbados is a field station of McGill University. Bellairs
Canadian Meteorological and Oceanographic Society. CMOS
Dalhousie University, Halifax, Nova Scotia. Oceanography Department
Fisheries and Oceans Canada, organized into seven administrative regions of Canada. Fisheries and Oceans Canada
Institute of Ocean Sciences in British Columbia, operated by Fisheries and Oceans Canada.
Maurice Lamontagne Institute in Mont Joli, Quebec, operated by Fisheries and Oceans Canada.
Memorial University, St. John's, Newfoundland and Labrador. Fisheries and Marine Institute
Northwest Atlantic Fisheries Centre in St. John's, Newfoundland and Labrador. NAFC
Ocean Frontier Institute, housed at the Memorial University of Newfoundland and Dalhousie University. OFI
Ocean Networks Canada, an ocean observing program run by the University of Victoria similar to the Ocean Observatories Initiative.
Université du Québec à Rimouski, Institut des Sciences de la mer ISMER
China
Chinese Academy of Sciences, Institute of Oceanology. Institute of Oceanology
Chinese Academy of Sciences, South China Sea Institute of Oceanology. SCSIO
East China Normal University's State Key Laboratory of Estuarine and Coastal Research SKLEC
Ocean University of China in Qingdao, Shandong. OUC
State Key Laboratory of Satellite Ocean Environment Dynamics in Hangzhou. SOED
State Oceanic Administration, First Institute of Oceanography. FIO
State Oceanic Administration, Second Institute of Oceanography. SIO.
The University of Hong Kong's Swire Institute of Marine Science on the Cape d'Aguilar Peninsula on Hong Kong Island. SWIMS
Colombia
Colombian national programs:
Centro de Investigaciones Oceanográficas e Hidrográficas del Caribe, General Maritime Directorate. CIOH
Centro de Investigaciones Oceanográficas e Hidrográficas del Pacífico, General Maritime Directorate. CCCP
José Benito Vives de Andréis Marine and Coastal Research Institute in Santa Marta, Magdalena. INVEMAR
Colombian universities with oceanography programs:
Colombian Naval Academy: Escuela Naval de Cadetes "Almirante Padilla" in Cartagena, Oceanography program.
EAFIT University in Medellín, Marine Sciences Group.
National University of Colombia’s School of Mines in Medellín, Oceanography and Coastal Engineering Research Group. OCEANICOS
Universidad Jorge Tadeo Lozano in Bogotá, Dynamics and Management of Coastal Marine Ecosystems program DIMARCO
University of Antioquia offers Oceanography undergraduate program and Marine Sciences doctorate program.
Croatia
Institute of Oceanography and Fisheries in Split is supported by the Croatian Science Foundation. IOR
Ruđer Bošković Institute, Center for Marine Research in Rovinj. CMR
University of Dubrovnik, Institute for Marine and Coastal Research. IMP-DU
Denmark
Danish Maritime Safety Administration in Copenhagen. DaMSA
Technical University of Denmark in Copenhagen.
Copenhagen University's Research Centre on Ocean, Climate, and Society. ROCS
Ecuador
Escuela Superior Politécnica del Litoral has programs in Marine Engineering, Biological Sciences, and Natural Resources. FIMCBOR
Instituto Oceanográfico de la Armada, part of the Ecuadorian Navy, in Guayaquil. INOCAR
Finland
Finnish Environment Institute's Marine Research Center. SYKE
Finnish Institute of Marine Research in Helsinki.
Finnish Meteorological Institute's Marine Research unit. FMI
France
Académie de Marine, originally the Royal Naval Academy of France. Académie de Marine
Banyuls-sur-Mer Oceanographic Observatory, also called Laboratoire Arago. OOB
European University Institute of Marine Sciences in Brest. IUEM
French Research Institute for Exploitation of the Sea in Brest. IFREMER
Institut océanographique de Paris, associated with an organization with the same name in Monaco.
Institute of Environmental Geosciences in Grenoble, associated with the Grenoble Alps University. IGE
Laboratory of Space Geophysical and Oceanographic Studies in Toulouse. LEGOS
Lille University of Science and Technology's Wimereaux Marine Station
Marine Biological Station and Concarneau Marinarium, associated with the French National Museum of Natural History. Station Marine de Concarneau
Marine Station of Arcachon, associated with the University Bordeaux, on Arcachon Bay. Station marine d'Arcachon
Mediterranean Institute of Oceanography in Marseille. MIO
Naval Hydrographic and Oceanographic Service in Brest. SHOM
Laboratoire d'Océanographie de Villefranche-sur-Mer on the French Riviera. [www.obs-vlfr.fr Obs-Vlfr]
Oceanography and Climate Laboratory in Paris LOCEAN
Paul Ricard Oceanographic Institute on the island of Embiez near Six-Fours-les-Plages.
Roscoff Marine Station, associated with Sorbonne University, is the oldest marine research station in the world. SB-Roscoff
Germany
Alfred Wegener Institute for Polar and Marine Research in Bremerhaven. AWI
Center for Marine Environmental Sciences in Bremen. MARUM
GEOMAR Helmholtz Centre for Ocean Research Kiel. GEOMAR
German Marine Research Consortium in Berlin. KDM
Helmholtz-Zentrum Hereon in Geesthacht, part of the Helmholtz Association, has research programs in marine sciences. HZG
Institute for Chemistry and Biology of the Marine Environment in Oldenburg, Wilhelmshaven. ICBM
Integrated School of Ocean Sciences at Kiel University. ISOS
Leibniz Institute for Baltic Sea Research in Warnemünde .IOW
Leibniz Centre for Tropical Marine Research in Bremen. ZMT
Max Planck Institute for Meteorology in Hamburg. MPI-M
Senckenberg by the Sea in Wilhelmshaven. Senckenberg am Meer
The Future Ocean, a collaborative research group based out of Kiel.
University of Hamburg's Institute of Oceanography. IfM
Greece
Hellenic Centre for Marine Research in Anavyssos. HCMR
University of the Aegean in Mytilene, Lesvos. Department of Marine Sciences
Iceland
Marine and Freshwater Research Institute in Hafnarfjörður, associated with the Ministry of Industries and Innovation. MFRI
University of Iceland's Marine Academic Research in Iceland group in Reykjavik. MARICE
India
Indian national programs:
Center for Marine Living Resources in Kerala, under the Ministry of Earth Sciences. CMLRE
Central Marine Fisheries Research Institute, Kochi, Kerala, under the Indian Council of Agricultural Research. CMFRI
National Centre for Ocean Information Services in Pragathi Nagar, Hyderabad. ESSO-INCOIS
National Institute of Oceanography in Goa.
National Atmospheric Research Laboratory in Andhra, Pradesh. NARL
National Centre for Polar and Ocean Research in Goa. NCAOR
National Centre for Sustainable Coastal Management in Chennai, Tamil Nadu. NCSCM
National Institute of Ocean Technology in Chennai, Tamil Nadu. NIOT
National Center for Coastal Research in Chennai, under the Ministry of Earth Sciences. NCCR
National Centre for Earth Science Studies in Kerala. NCESS
Central Institute of Brackishwater Aquaculture in Chennai, Tamilnadu. CIBA
Central Institute of Fisheries Technology in Cochin, Kerala. ICFT
Central Institute of Fisheries Education in Mumbai. CIFE
Fishery Survey of India in Mumbai. FSI
National Institute of Fisheries Post Harvest Technology and Training in Ernakulum, Kerala. NIFPHATT
Indian universities with oceanography programs:
Central:
University of Allahabad, K. Banerjee Centre for Atmospheric and Ocean Studies. KBCAOS
Eastern:
Indian Institute of Technology Kharagpur’s Centre for Oceans, Rivers, Atmosphere and Land Sciences (CORAL) in West Bengal.
Berhampur University, Department of Marine Sciences, Odisha.
University of Calcutta, Department of Marine Science, Kolkata. MarineSc
Jadavpur University, School of Oceanographic Studies, Kolkata. Ocean-JU
Indian Institute of Technology Bhubaneswar, School of Earth, Ocean and Climate Sciences, Odisha. IIT Bhubaneswar OC
Northern:
Indian Institute of Technology Delhi, Centre for Atmospheric Sciences. CAS
Central University of Punjab, Bathinda.
Southern:
Academy of Maritime Education and Training in Chennai, Tamil Nadu.
Andhra University, Department of Meteorology and Oceanography.
Anna University, Institute of Ocean Management, Chennai, Tamil Nadu. IOM
Annamalai University, Center of Advanced Study in Marine Biology, Tamil Nadu. CASMB
Alagappa University, Karaikudi, Tamil Nadu. Department of Fisheries Science Department of Oceanography and Coastal Area Studies, Alagappa University, Karaikudi, Tamil Nadu.
Bharathidasan University, Tiruchirappalli. Department of Marine Science
Cochin University of Science and Technology in Kerala. has several departments in its School of Marine Sciences. SMSCUSAT
Indian Institute of Science ‘s Centre for Atmospheric and Oceanic Sciences in Bengalaru. CAOS
Kerala University of Fisheries and Ocean Studies in Kochi, Kerala.
Madurai Kamaraj University, School of Energy Environment & Natural Resources, Tamil Nadu. SEENR
Manonmaniam Sundaranar University, Centre for Marine Science and Technology, Rajakkamangalam, Kanyakumari. CMST
M.E.S. Ponnani College, Ponnani, Malappuram, Kerala. Department of Aquaculture and Fishery Microbiology
Nansen Environmental Research Centre India, Kerala, established by joint Norwegian and Indian partners, now a research center of Kerala University. NERCI
Pondicherry University, Department of Ocean Studies and Marine Biology, Port Blair, Andaman Islands. Center for Ocean and Island Studies
St. Albert's College, Kochi, Kerala. Department of Fisheries & Aquaculture
University of Hyderabad, Center for Earth, Ocean, and Atmospheric Sciences, formerly called the formerly Centre for Earth and Space Sciences. CEOAS
University of Kerala, Department of Aquatic Biology and Fisheries.
University of Madras, Centre for Ocean and Coastal Studies, Chennai, Tamil Nadu. COCS
Western:
Goa University, Department of Marine Sciences. Department of Marine Sciences
Indonesia
Bandung Institute of Technology has programs in Oceanography under the Faculty of Earth Sciences and Technology and Ocean Engineering under the Faculty of Civil and Environmental Engineering.
Bogor Agricultural Institute, Department of Marine Science and Technology.
Diponegoro University, Faculty of Fisheries and Marine Sciences, Semarang, Central Java.
Indonesian Institute of Sciences’s Research Center for Oceanography, Jakarta. Puslit Oseanografi LIPI
University of Riau, Marine Science Department, Pekanbaru.
Iran
Tarbiat Modares University, Marine Science Faculty, Tehran.
Iranian National Institute for Oceanography and Atmospheric Science, Tehran.
Khorramshahr Marine Science and Technology University, Khorramshahr. KMSU
Islamic Azad University, Science and Research Branch, Tehran, Faculty of Marine Science and Technologies.
Ireland
Marine Institute Ireland, a state agency in Galway.
National University of Ireland, Galway, Ryan Institute for Environmental, Marine and Energy Research. The Ryan Institute
University College Cork, SFI Research Centre for Energy, Climate and Marine research and innovation. MaREI
Israel
Ben-Gurion University of the Negev, Beersheba. Department of Earth and Environmental Sciences
Israel Oceanographic & Limnological Research Institute, which has research centers in Haifa, Kinneret, and Eilat. IOLR
University of Haifa, The Leon H. Charney School of Marine Sciences in Haifa. MarSci Haifa
Italy
Italian National Research Council, Institute for the Study of Anthropic Impacts and Sustainability in Marine Environment. CNR-IAS
Italian National Research Council, Institute for Marine Biological Resources and Biotechnology. CNR-IRBIM
Italian National Research Council, Institute of Marine Sciences. CNR-ISMAR
National Institute of Oceanography and Experimental Geophysics (Istituto Nazionale di Oceanografia e di Geofisica Sperimentale) in Sgonico. OGS
National Inter-University Consortium of Marine Sciences, a collaboration between 35 Italian Universities. CoNISMa
Japan
Okinawa Institute of Science and Technology in Onna, Okinawa, includes Marine Science as one subject in the multi-disciplinary research profile of the graduate program. OIST
Japan Agency for Marine-Earth Science and Technology in Yokosuka, Kanagawa. JAMSTEC
Tokyo University of Marine Science and Technology in Koto, Tokyo. TUMSAT
Kobe University, Department of Oceanology, Kobe, Hyogo. Faculty of Oceanology
University of the Ryukyus in Nakagami, Okinawa includes Oceanography and Marine Biology as areas of study. Faculty of Science
Usa Marine Biological Institute in Usa, Kochi.
Latvia
Institute of Food Safety, Animal Health and Environment “BIOR” in Riga conducts research in the areas of Environmental Science and Fisheries. BIOR
Latvian Institute of Aquatic Ecology, Riga. LIAE
Lithuania
Klaipėda University, Coastal Research and Planning Institute, on the Baltic Sea coast.
Mexico
Autonomous University of Baja California, Ensenada, Institute for Oceanographic Research, and Faculty of Marine Sciences. UABC IIO, UABC Facultad de Ciencias Marinas
Autonomous University of Sinaloa, Faculty of Marine Sciences in Mazatlán.
Centro de Investigaciones Biológicas del Noroeste S.C, under the direction of the Consejo Nacional de Ciencia y Tecnología (Mexico), in La Paz, Baja California Sur. CIBNOR
Centro Interdisciplinario de Ciencias Marinas del Instituto Politécnico Nacional, located in La Paz, Baja California Sur. CICIMAR
El Colegio de la Frontera Sur, in Chetumal, Quintana Roo on the Yucatán Peninsula, under the direction of the Consejo Nacional de Ciencia y Tecnología (Mexico). ECOSUR
Ensenada Center for Scientific Research and Higher Education on the Pacific Coast of the Baja Peninsula. CICESE
National Autonomous University of Mexico, Instituto de Ciencias del Mar y Limnología, campuses in México City, Mazatlán and Puerto Morelos. ICMYL
Universidad del Mar, Puerto Ángel, Oaxaca UMAR
University of Colima, Facultad de Ciencias Marinas. FACIMAR
Monaco
Institut océanographique, associated with the organization of the same name in Paris, France. Oceano
Netherlands
Royal Netherlands Institute for Sea Research on the island of Texel, and in Yerseke. NIOZ
University of Groningen, program in Marine Biology. RUG Marine Biology
New Zealand
Cawthron Institute in Nelson on the South Island. Cawthron
National Institute of Water and Atmospheric Research, whose head office is in Auckland but with several other sites across New Zealand, was formerly part of the N.Z. Oceanographic Institute. NIWA
Victoria University Coastal Ecology Laboratory on the Wellington coast of the North Island. WUCEL
Norway
Geophysical Institute, University of Bergen.
Norwegian Institute of Marine Research in Bergen.
Norwegian Polar Institute in Tromsø.
University of Tromsø’s Norwegian College of Fishery Science and Department of Arctic and Marine Biology.
Pakistan
Lasbela University of Agriculture, Water & Marine Science, Balochistan. LUAWMS
National Institute of Oceanography, part of the Ministry of Science and Technology. NIOPK
Philippines
Marine Science Institute, part of the University of the Philippines, UP Diliman, in Quezon City. MSI
Poland
Institute of Oceanology, Polish Academy of Science, Sopok. IO PAN
National Marine Fisheries Research Institute, Gdynia. MIR
University of Gdańsk, Institute of Oceanography. UG Oceanography
Maritime Institute in Gdańsk. IM GDA
Polish Polar Station, Hornsund in Svalbard in the Arctic Ocean.
Portugal
Centre of Marine Sciences in Faro. CCMAR
Hydrographic Institute in Lisbon. Instituto Hidrografico
Department of Oceanography and Fisheries, University of Azores in Horta, Faial.
Interdisciplinary Centre of Marine and Environmental Research in Matosinhos. CIIMAR
Marine Biology Station of Funchal on the island of Madeira.
Marine and Environmental Sciences Centre, a multi-university collaboration. MARE
Russia
Marine Hydrophysical Institute, Russian Academy of Sciences. MHI
Nikolai M. Knipovich Polar Research Institute of Marine Fisheries and Oceanography in Murmansk
Russian State Hydrometeorological University in St. Petersburg
Saint Petersburg State University, Department of Oceanography
Shirshov Institute of Oceanology, Russian Academy of Sciences
Pacific Oceanological Institute, Far-Eastern Branch, Russian Acad. of Sciences, Vladivostok
South Africa
South African Association for Marine Biological Research in KwaZulu-Natal. SAAMBR
Department of Oceanography, University of Cape Town
South Korea
Korea Institute of Ocean Science and Technology. KIOST
Pusan National University, Department of Oceanography.
Seoul National University, School of Earth and Environmental Sciences.
Spain
Andalusian Center for Marine Science and Technology, sponsored by the University of Cádiz. CACYTMAR
Institute of Marine Science of Andalusia. ICMAN
Marine Research units of AZTI, located in multiple cities in the Basque region. AZTI
Marine Sciences Institute in Barcelona. ICM
Marine Technology Unit, part of the Spanish National Research Council. UTM
Oceanic Platform of the Canary Islands. PLOCAN
Spanish Institute of Oceanology, Madrid. IEO
Sri Lanka
National Aquatic Resources Research and Development Agency. NARA
Ocean University of Sri Lanka in Colombo.
University of Ruhuna, Faculty of Fisheries and Marine Sciences & Technology. FMST
Sweden
Baltic Sea Science Center, Skansen, Stockholm.
Stockholm University’s Baltic Sea Centre, based in Stockholm but with a laboratory in Asko. Baltic Sea Centre
Swedish Maritime Robotics Centre, Stockholm. SMaRC
University of Gothenburg, Department of Marine Sciences, including Kristineberg Marine Research Station and Tjärnö Marine Laboratory. Marina Vetenskaper
Taiwan
China Maritime Institute in Taipei City. Maritime Institute
National Academy of Marine Research in Kaohsiung.
National Dong Hwa University, Graduate Institute of Marine Biology. NDHU IMB
National Sun Yat-sen University, College of Marine Sciences. Marine NSYSU
National Taiwan Normal University, Institute of Marine Environmental Science and Technology. NTNU
National Taiwan Ocean University in Zhongzheng, Keelung. NTOU
National Taiwan University, Institute of Oceanography. NTU OC
Taiwan Ocean Research Institute, Kaohsiung. TORI
Tanzania
Western Indian Ocean Marine Science Association, headquartered in Zanzibar.
Turkey
Dokuz Eylül University, Institute of Marine Sciences and Technology, Izmir. DEU
Institute of Marine Sciences, part of Middle East Technical University, Erdemli and Mersin. IMS
Istanbul University, Institute of Marine Sciences and Management. Deniz Bilimleri
Office of Navigation, Hydrography and Oceanography, part of the Turkish Navy. ONHO
United Kingdom
Bangor University, School of Ocean Sciences. Ocean Sciences
British Oceanographic Data Centre in Liverpool. BODC
Challenger Society for Marine Science, a learned society.
FSC Millport, formerly known as the University Marine Biological Station Millport, on the Firth of Clyde, Scotland.
Dove Marine Laboratory in North Shields, associated with Newcastle University.
Gatty Marine Laboratory, associated with the University of St. Andrews, Scotland.
Marine Biological Association of the United Kingdom, Plymouth, Devon.
Marine Scotland Directorate, formerly called Marine Scotland Science, headquartered in Leith, Edinburgh.
Met Office Hadley Centre, Exeter. Met Office
National Oceanography Centre including the National Oceanography Centre, Southampton.
National Tidal and Sea Level Facility, including the UK National Tide Gauge Network. NTSLF
Plymouth Marine Laboratory in Devon.
Proudman Oceanographic Laboratory in Liverpool.
Scott Polar Research Institute, Cambridge. SPRI
Scottish Association for Marine Science, Dunstaffnage, Oban. SAMS
United States
National agencies and non-profit organizations:
Integrated Ocean Observing System, a network of regional observing systems.
Ocean Observatories Initiative, a collaboration between WHOI, OSU, UW, and Rutgers.
NASA Goddard Space Flight Center’s Ocean Biology and Biogeochemistry Program
National Data Buoy Center
National Oceanic and Atmospheric Administration, within which there are several affiliate “joint” programs co-hosted by other institutions.
National Undersea Research Program
Naval Oceanographic Office, Stennis Space Center, Mississippi, also home to the Naval Meteorology and Oceanography Command. NAVOCEANO
Schmidt Ocean Institute
Sea Education Association, also known as SEA Semester. SEA
University-National Oceanographic Laboratory System. UNOLS
Universities with oceanography programs:
Northeast:
Bigelow Laboratory for Ocean Sciences in Maine. Bigelow
University of Maine, School of Marine Sciences based in Orono and the Downeast Institute at the Machias campus.
Lamont–Doherty Earth Observatory associated with Columbia University in Palisades, New York.
Marine Biological Laboratory in Woods Hole, Massachusetts, associated with the University of Chicago. MBL
Northeastern University, Marine Science Center, East Point, Nahant, Massachusetts. Marine Science Center
Stony Brook University, School of Marine and Atmospheric Sciences, on Long Island, New York State. SoMAS
Princeton University’s Geophysical Fluid Dynamics Laboratory, New Jersey.
Rutgers University, Department of Marine and Coastal Sciences, is based in New Brunswick, New Jersey with other marine science field stations in New Jersey.
University of Connecticut, Department of Marine Sciences, at the Avery Point campus near Groton, Connecticut, also host to the National Undersea Research Center for the North Atlantic and Great Lakes. DMS
Woods Hole Oceanographic Institution on Cape Cod, Massachusetts. WHOI
University of Delaware, College of Earth, Ocean and Environment, which has a campus in Lewes, Delaware. CEOE
University of Massachusetts Dartmouth, School for Marine Science & Technology. SMAST
University of New Hampshire’s School of Marine Science and Ocean Engineering, Center for Coastal & Ocean Mapping, and Shoals Marine Laboratory.
University of New England (United States) has programs in marine science at the Biddeford, Maine campus. Marine Programs.
University of Rhode Island’s Graduate School of Oceanography, also has a Center for Ocean Exploration and Archaeological Oceanography.
Southeast:
Duke University Marine Laboratory near Beaufort, North Carolina. Duke Marine Lab
Halmos College of Natural Sciences and Oceanography at Nova Southeastern University, Florida.
Harbor Branch Oceanographic Institution at Florida Atlantic University in Fort Pierce, Florida. HBOI
Florida Institute of Technology, School of Marine and Environmental Technology in Melbourne, Florida.
Florida State University, Department of Earth, Ocean & Atmospheric Science in Tallahassee and Coastal Marine Laboratory in St. Teresa. EOAS
Old Dominion University, department of Ocean & Earth Sciences, Norfolk, Virginia. OES
Rosenstiel School of Marine, Atmospheric, and Earth Science, University of Miami, Florida. RSMAS
Skidaway Institute of Oceanography, Georgia. SKIO
University of Georgia Marine Institute on Sapelo Island. UGAMI
University of North Carolina at Wilmington, Center for Marine Science. UNCW CMS
University of South Carolina, School of the Earth, Ocean and Environment headquartered in Columbia, South Carolina, as well as the Baruch Institute, a research station near Georgetown, South Carolina. SEOE
Virginia Institute of Marine Science, located in Gloucester Point, Virginia, part of William & Mary. VIMS
Whitney Laboratory for Marine Bioscience, part of the University of Florida, in Saint Augustine. Whitney Laboratory
Gulf Coast:
Dauphin Island Sea Lab on the barrier island where Fort Gaines is located, part of the University of South Alabama. DISL
Florida Institute of Oceanography, housed at the University of South Florida St. Petersburg. FIO
Louisiana State University, College of the Coast & Environment. CCE
Texas A&M University, Department of Oceanography, based in College Station, Texas but with a campus in Galveston, Texas. TAMU Oceanography
University of Southern Mississippi, School of Ocean Science and Engineering, with locations in Long Beach, Ocean Springs, and the Stennis Space Center. SOSE
University of Texas Marine Science Institute in Port Aransas, Texas. UTMSI
West Coast:
Cal Poly Humboldt, Marine Sciences program, Arcata, California. Humboldt Marine Sciences
Center for the Blue Economy in Monterey, California, managed by the Middlebury Institute of International Studies.
Hawaii Pacific University in Honolulu and Kaneohe, Hawaii.
Hatfield Marine Science Center in Newport, Oregon is operated by Oregon State University, College of Earth, Ocean, and Atmospheric Sciences. CEOAS
Hopkins Marine Station, run by Stanford University, in Monterey, California. Hopkins
Monterey Bay Aquarium Research Institute in Monterey, California. MBARI
Moss Landing Marine Laboratories, run by the California State University system, in Moss Landing, California. MLML
Naval Postgraduate School, Monterey, California. NPS
Pacific Marine Environmental Laboratory, part of NOAA, split between Newport, Oregon and Seattle, Washington. PMEL
San Diego State University operates the Coastal Waters Laboratory in San Diego, California.
Scripps Institution of Oceanography, associated with the University of California San Diego, in La Jolla, California. Scripps
Southern California Marine Institute, a multi-campus research station on Terminal Island in the Los Angeles area.
University of Alaska Fairbanks, College of Fisheries and Ocean Sciences, which also houses the Cooperative Institute for Arctic Research, is based in Fairbanks, Alaska and also has a small station in Seward, Alaska. CFOS
University of California Davis, Coastal and Marine Sciences Institute, which also runs the Bodega Marine Laboratory and Bodega Marine Reserve in Sonoma County, California. UCDavis Marine Science
University of California Santa Barbara, Marine Science Institute. UCSB MSI
University of California Santa Cruz Coastal Science Campus, Institute of Marine Sciences. UCSC IMS
University of Hawaii at Manoa’s School of Ocean and Earth Science and Technology houses the Center for Microbial Oceanography: Research and Education and the Hawaii Undersea Research Laboratory. SOEST
University of Washington, School of Oceanography, Seattle, Washington. UW Ocean
Western Washington University, Shannon Point Marine Center, Anacortes, Washington. SPMC
Inland and Great Lakes:
National Center for Atmospheric Research, Boulder, Colorado.
University Corporation for Atmospheric Research, Boulder, Colorado.
University of Colorado Boulder, which houses the Cooperative Institute for Research in Environmental Sciences and the Institute of Arctic and Alpine Research.
University of Michigan, Department of Earth and Environmental Sciences, Oceanography program. U-M
Venezuela
Oceanographic Institute of Venezuela in Cumana.
Vietnam
Institute of Marine Environment and Resources in Haiphong, part of the Vietnam Academy of Science and Technology. IMER
Institute of Marine Geology and Geophysics in Hanoi, part of the Vietnam Academy of Science and Technology. IMGG
International Centre for Interdisciplinary Science and Education in Quy Nhon, Binh Dinh. ICISE
Nha Trang Oceanography Institute in Khánh Hòa Province. VNIO
University of Science and Technology of Hanoi, Water-Earth-Environment Program. WEO
See also
:Category:Oceanographic organizations
:Category:Fisheries and aquaculture research institutes
Earth science
List of environmental research institutes
List of research vessels by country
Oceanography
Outline of Earth sciences
Outline of oceanography
References
Geography-related lists
Earth sciences
Environmental science
Lists of places
Lists of universities and colleges
Maritime organizations
Oceanography | List of oceanographic institutions and programs | [
"Physics",
"Environmental_science"
] | 6,413 | [
"Oceanography",
"Hydrology",
"Applied and interdisciplinary physics",
"nan"
] |
17,580,984 | https://en.wikipedia.org/wiki/Cedarlane%20Laboratories | Cedarlane is a Canadian private corporation headquartered in Burlington, Ontario, Canada, that manufactures and distributes life science research products. Cedarlane's manufactured products include monoclonal antibodies, polyclonal antibodies, cell separation media, complement for tissue typing, and immunocolumns. Cedarlane is an ISO 9001:2008 and ISO 13485:2003 registered company. Cedarlane has become a multi-national corporation with over 100 employees in Canada and the United States. The two main locations are in Burlington, Ontario, Canada and coincidentally, in Burlington, North Carolina, US.
In recent years, Cedarlane has partnered with a number of charitable Canadian organizations to raise funding for cancer research, economically impoverished children, men's health initiatives and other causes. Cedarlane has partnered with the likes of the Canadian Cancer Society, Canadian Breast Cancer Foundation, SickKids Foundation, and others.
History
Cedarlane was incorporated in 1975 by three Canadian researchers originating from the University of Toronto and Ontario Cancer Institute; Dr. S. Abrahams, Dr. A.J. Farmilo and R.C. Course.
In 2006, Cedarlane opened a branch office in Burlington, North Carolina, in the United States.
In July 2007, Cedarlane became the exclusive distributor of ATCC products in Canada. In November, Cedarlane acquired CELLutions Biosystems Inc., a company founded by the University of Toronto Innovations Foundation.
Products
Cedarlane sells density-gradient cell separation media under the Lympholyte trade name.
Cedarlane offers cell line platforms and various marker details (under CELLutions™) for academic and commercial research programs.
Cedarlane also distributes over 5 million products on behalf of more than 1400 global Life Science manufacturing companies.
References
External links
Cedarlane company website
Biotechnology companies of Canada
Privately held companies of Canada
Life sciences industry | Cedarlane Laboratories | [
"Biology"
] | 371 | [
"Life sciences industry"
] |
17,581,319 | https://en.wikipedia.org/wiki/InSSIDer | inSSIDer is a Wi-Fi network scanner application for Microsoft Windows and OS X developed by MetaGeek, LLC. It has received awards such as a 2008 Infoworld Bossie Award for "Best of Open Source Software in Networking", but as of inSSIDer 3, it is no longer open-source.
History
inSSIDer began as a replacement for NetStumbler, a popular Windows Wi-Fi scanner, which had not been actively developed for several years and reputedly did not work with modern 64-bit operating systems or versions of Windows higher than Windows XP. The project was inspired by Charles Putney on The Code Project.
Features
New in Version 5.0: channel utilization break down to show device (AP and client) airtime utilization; see connected client devices and info about client such as utilization and signal strength
Gathers information from wireless card and software
Helps choose the best wireless channel available
Wi-Fi network information such as SSID, MAC, vendor, data rate, signal strength, and security
Graphs signal strength over time
Shows which Wi-Fi network channels overlap
System requirements
Windows
Version 5.0: Microsoft Windows 7 or higher
Version 3.0: Microsoft Windows XP SP3 or higher
Version 2.1: Microsoft Windows XP SP2
Microsoft .NET Framework 3.5 or higher
OS X
OS X Mountain Lion 10.8 or higher
References
External links
(Apache 2.0 license)
Wireless networking
MacOS network-related software
MacOS security software
Windows network-related software
Windows security software | InSSIDer | [
"Technology",
"Engineering"
] | 304 | [
"Wireless networking",
"Computer networks engineering"
] |
17,581,476 | https://en.wikipedia.org/wiki/Harnack%20Medal | The highest award which is presented by the Max Planck Society for services to society is the Harnack Medal, first awarded in 1925. The Harnack Medal is named after the theologian Adolf von Harnack, who was the first president of the Kaiser Wilhelm Society, the predecessor organization of the MPG, from 1911 to 1930. The medal has only been awarded 33 times since 1924, including 10 times by the Kaiser Wilhelm Society (1924–1936) and 23 times by the Max Planck Society (1953–2017).
Past recipients of the Harnack Medal are:
Daniel Zajfman 2023
Angela Merkel 2021
Peter Gruss 2017
Hermann Neuhaus 2008
Lu Yongxiang 2006
Hubert Markl 2004
Haim Harari 2001
Hans F. Zacher 1998
Michael Sela 1996
Heinz A. Staab 1996
Reimar Lüst 1993
Richard von Weizsäcker 1990
Hans Merkle 1984
Kurt Birrenbach 1981
Walther Gerlach 1974
Adolf Butenandt 1973
Carl Wurster 1970
Alfred Kühn 1965
Heinrich Lübke 1964
Otto Heinrich Warburg 1963
Georg Schreiber 1962
Erich Kaufmann 1960
Theodor Heuss 1959
Otto Hahn 1954 (in Gold 1959)
Gustav Winkler 1953
Ludwig Prandtl 1936
Albert Vögler 1936
Carl Duisberg 1934
Max Planck 1933
Gustav Krupp von Bohlen und Halbach 1933
Franz von Mendelssohn 1932
Carl Correns 1932
Friedrich Schmidt-Ott 1929
Fritz Haber 1926
Adolf von Harnack 1925
References
External links
Science and technology awards
Max Planck Society | Harnack Medal | [
"Technology"
] | 311 | [
"Science and technology awards",
"Science award stubs"
] |
17,582,938 | https://en.wikipedia.org/wiki/FlightCheck | FlightCheck is a stand-alone application that performs preflight quality control inspection on many common file types such as Adobe InDesign, Adobe Photoshop, Adobe Illustrator, QuarkXPress, and PDF.
Preflight in the graphic arts industry is the process of checking a digital document before it goes to the plate, print, or otherwise output (exported - such as to PDF). It is a way to check the quality before printing, digitally or otherwise, but it can also be used to check any common artwork file. Preflight may be done on the source desktop publishing document, or before creating a Portable Document Format (PDF) file. The term preflight was first used during a presentation in 1990 by Chuck Weger, a well-known industry consultant. There were some early postscript RIPs that interpreted data and provided a preflight report of sorts.
The first commercial preflight application, called "FlightCheck," was introduced to the public by Markzware and appeared at the Seybold Seminars Conference at San Francisco in the Fall of 1995. U.S. Patent, number 5,963,641 was subsequently granted - ‘Device and method for examining, verifying, correcting and approving electronic documents prior to printing, transmission or recording.’
Other preflighting tools have subsequently been introduced, mainly focusing on PDF preflighting.
References
Desktop publishing software
Printing software | FlightCheck | [
"Technology"
] | 286 | [
"Computing stubs",
"Digital typography stubs"
] |
17,582,972 | https://en.wikipedia.org/wiki/Transaction%20Processing%20Performance%20Council | The Transaction Processing Performance Council (TPC), founded in 1988, is a non-profit organization founded to define benchmarks for transaction processing and databases, and to publish objective, verifiable TPC performance data to the industry. TPC benchmarks are used in evaluating the performance of computer systems, and TPC publishes the results.
Conference Series
In 2009 the TPC initiated an International Technology Conference Series on Performance Evaluation and Benchmarking (TPCTC), a forum for industry experts and researchers to discuss and develop techniques for evaluation, measurement and characterization of modern application systems. The conference series was founded in 2009 by Raghunath Nambiar of Cisco and Meikel Poess in 2009.
TPCTC 2009, in conjunction with VLDB 2009 on August 24, 2009 in Lyon, France.
TPCTC 2010, in conjunction with VLDB 2010 on September 17, 2010 in Singapore.
TPCTC 2011, in conjunction with VLDB 2011 on August 29, 2011 in Seattle, Washington.
TPCTC 2012, in conjunction with VLDB 2012 on August 27, 2012 in Istanbul,Turkey.
TPCTC 2013, in conjunction with VLDB 2013 on August 26, 2013 in Trento, Italy.
TPCTC 2014, in conjunction with VLDB 2014 on September 5, 2014 in Hangzhou, China.
TPCTC 2015, in conjunction with VLDB 2015 on August 31, 2015 in Kohala Coast, Hawaii.
TPCTC 2016, in conjunction with VLDB 2016 on September 5, 2016 in New Delhi, India.
Standards
TPC-C – On-line transaction processing (since 1992)
TPC-H – Ad-hoc decision support system (since 1999)
TPC-E – Complex on-line transaction processing (since 2006)
TPC-DS – Complex decisions support system (since 2011)
TPC-DI – Data integration (since 2013)
TPCx-HS – Industry's first standard for benchmarking Big Data (Hadoop) systems (since 2014)
Obsolete benchmarks
TPC-A – Measures performance in update-intensive database environments typical in on-line transaction processing applications. (Obsolete as of June 6, 1995)
TPC-App – An application server and web services benchmark.
TPC-B – Measures throughput in terms of how many transactions per second a system can perform. (Obsolete as of June 6, 1995)
TPC-D – Represents a broad range of decision support applications that require complex, long running queries against large complex data structures. (Obsolete as of April 6, 1999)
TPC-R – A business reporting, decision support benchmark. (Obsolete as of January 1, 2005)
TPC-W – A transactional web e-Commerce benchmark. (Obsolete as of April 28, 2005)
References
Software engineering organizations
Organizations based in San Francisco
1988 establishments in California | Transaction Processing Performance Council | [
"Engineering"
] | 592 | [
"Software engineering",
"Software engineering organizations"
] |
17,582,998 | https://en.wikipedia.org/wiki/The%20Sleep%20of%20Reason%20Produces%20Monsters | The Sleep of Reason Produces Monsters or The Dream of Reason Produces Monsters () is an aquatint by the Spanish painter and printmaker Francisco Goya. Created between 1797 and 1799 for the , it is the 43rd of the 80 aquatints making up the satirical .
Subject
is a series of 80 etchings published in 1799 wherein Goya criticized the rampant political, social, and religious abuses of the time period. In this series of etchings, Goya heavily utilized the popular technique of caricature, which he enriched with artistic innovation. Goya's usage of the recently-developed technique of aquatint (i.e., a method of etching a printing plate so that tones similar to watercolor washes can be reproduced) gave pronounced tonal effects and spirited contrast that made them a major achievement in the history of engraving.
Of the 80 aquatints, number 43, "The Sleep of Reason Produces Monsters", can be viewed as Goya's personal manifesto; many observers believe that Goya intended to depict himself asleep amidst his drawing tools, his reason dulled by slumber, bedeviled by creatures that prowl in the dark. Such creatures that appear in this work are often associated in Spanish folk tradition with mystery and evil; the owls surrounding Goya may be symbols of folly, and the swarming bats may symbolize ignorance. The title of the print, as marked on the front of the desk, is typically read as a proclamation of Goya's adherence to the values of the Enlightenment: without reason, evil and corruption prevail. Goya also included a caption for this print that may suggest a slightly different interpretation: "Imagination abandoned by reason produces impossible monsters; united with her, she is the mother of the arts and source of their wonders". This implies that Goya believed that imagination should never be completely renounced in favor of the strictly rational, as imagination (in combination with reason) is what produces works of artistic innovation.
Implied in Goya's preparatory inscription, the artist's nightmare reflects his view of Spanish society, which he portrayed in the as demented, corrupt, and ripe for ridicule.
The full epigraph for No. 43 reads; "Fantasy abandoned by reason produces impossible monsters: united with her [reason], she [fantasy] is the mother of the arts and the origin of their marvels."
Goya and satire
Goya's print has sometimes been interpreted in the context of satire. During the late eighteenth and early nineteenth century in Spain, Goya's paintings and etchings combined artistic innovation with social criticism to create visually-satirical works. Goya created numerous portraits of Spanish royalty that were quite realistic, and completed these portraits with jarring social commentary that marked a departure from the practice of painting royal figures with sensational opulence and splendor.
, Goya's set of 80 aquatints that were published in the year 1799, revealed and emphasized the innumerable flaws that human beings inherently possess. The series of works as a whole deals with the uniquely-human vices of "...vanity, greed, superstition, promiscuity and delusion". Particularly, 'The Sleep of Reason Produces Monsters' exhibits (quite literally) the treacherous lengths of human irrationality, and the implications of excessive illogicality without the counterbalance of reason. The remainder of the aquatints featured in incorporated contentious subjects including marriage, prostitution, the law, and the Church; some of these works featured specific and targeted political satire, implying Goya's dismay at the developments of Spanish political life. Goya supplemented these works with caustic and sardonic captions, augmenting the overall satirical effect.
Goya's stylistic progression up to
Goya's artistic career was initially marked by his creation of artwork for the Spanish royalty; Goya was called to Madrid to produce preliminary paintings in the form of tapestry cartoons for the Royal Tapestry Factory of Santa Barbara (). Goya began to produce oil-on-canvas cartoon paintings from which tapestries for the royal palaces could be made. According to many relevant sources of the time period, Goya displayed extraordinary skill in painting tapestry cartoons, and his talent apparently warranted the attention of the Neoclassical painter Anton Raphael Mengs. Some of the preliminary paintings he completed in Madrid included a series of nine hunting scenes for the dining room at the Royal Monastery of (located in the municipality of near Madrid), as well as a series of ten cartoons for tapestries in the dining room of the Royal Palace of El Pardo.
As Goya continued to engage with members of the aristocracy, he was met with an increasing quantity of royal patronage and received commissions at a higher frequency. Between the years of 1785 and 1788, Goya created works that depicted executives and their families from the Bank of San Carlos () in Spain. In 1786, Goya was appointed the official painter to King Charles III, and in 1789 he was promoted to Court Painter under Charles IV (1788–1808) who had recently ascended to the throne.
In the year 1792, Goya contracted an illness that left him permanently deaf; historians are unsure what the precise illness was that he suffered from, but it is speculated that Goya contracted either lead poisoning or "colic of Madrid" (a metal poisoning produced by cooking utensils), or some form of palsy. This illness caused him to suffer from an inability to balance on his feet, temporary blindness, and permanent deafness, which profoundly affected his life and his artistic style. In the years following his going deaf, Goya spent much of his time isolated from the outside world, as he asserted that he was unable to resume his work on large tapestry cartoons, and thus he turned to more personal projects. During this time, he studied the events and philosophies of the French Revolution, and created a series of etchings portraying the inherent vices and cruelties of human nature in a more pessimistic and sardonic style for which he would later become known. This series of prints, namely , were published in 1799 and depicted the confines of human reason, featuring whimsical and fantastical creatures that invade the mind during dreams, as displayed in 'The Sleep of Reason Produces Monsters' ().
During the year 1799, Goya was promoted by the Spanish crown to the position of First Court Painter, and spent the next two years working on a portrait of the family of Charles IV. In 1801, Goya published Charles IV of Spain and His Family, an oil painting that displays Charles IV of Spain and his family. Influenced by Diego Velázquez's , Goya painted the royal family in the foreground and himself in the background at an easel. This painting was shocking as it was very detailed and naturalistic; critics widely believed that the painting was meant as a criticism of the royal family as the members of the family were portrayed in a physically-unflattering manner.
Goya and the Enlightenment
Goya's echo key themes of the Enlightenment, particularly the prioritization of freedom and expression over custom and tradition, and the emphasis on knowledge and intellect over ignorance. Goya's The Sleep of Reason Produces Monsters presents a similar concept; this work praises reason as a work of imagination, such that it is on the basis of the imagination that reason "sleeps", and the abundance of imagination with an absence of reasoning and logic may produce "monsters". One of the work's critics writes, "[The animals] symbolize the world's 'vulgar prejudices' and 'harmful ideas commonly believed'. Goya, borrowing the penetrating vision of the lynx, intended to expose them to light by depicting them so that we can recognize and fight them, perpetuating the solid testimony of the truth... When we are asleep we do not see, nor can we denounce, the monsters of ignorance and vice." This interpretation of The Sleep of Reason Produces Monsters reflects the ideals of the Enlightenment by denouncing ignorance and highlighting the importance of awareness.
This conventional interpretation of this plate--an endorsement of Enlightenment ideology, translating sueño as "sleep" rather than the equally justifiable translation as "dream"--remains for the most part silent about motives for its placement in the center of the series. Interpreted as The Sleep of Reason Produces Monsters, Plate 43 might have made an ideal frontispiece for the plates to follow in the first half, as humans beings do exhibit monstrous behavior without using "reason". This would then be a usual Enlightenment criticism of society. By placing Plate 43 in the middle, as it is, what follows in the second half is also an Enlightenment criticism of society--but a very dark satire of the first half. It is the Enlightenment gone mad, run amok; it begins with The Dream of Reason Produces Monsters. John J. Ciofalo has written: "Truly, however, placing it in the middle made its meaning unmistakable and unleashed in Los Caprichos a potent, even explosive, narrative power...the gateway from the "dream" of reason into the nightmare of reason, indeed, of madness." Goya turns the light of the Enlightenment back on itself and here are where the monsters are found.
Preparatory drawings
On the preparatory drawings for The Sleep of Reason Produces Monsters, Goya explained (in reference to the artist that is depicted asleep), "His only purpose is to banish harmful, vulgar beliefs, and to perpetuate in this work of caprices the solid testimony of truth." Art historian Philip Hofer has suggested on the evidence of one of the preparatory sketches that Goya had intended for this work to be the frontispiece of , but Goya ultimately opted for The Sleep of Reason Produces Monsters to be the 43rd etching out of the 80 total. This work apparently provides a transition from the first half of , which includes more elements related to the vices of humanity, whereas the second half of the series introduces more fantastical creatures such as witches and goblins. Philip Hofer posits that the illustration on a title page of one of Jean-Jacques Rousseau's volumes influenced Goya's composition in this work, but that Goya ultimately decided not to display this as the frontispiece because it would seem speculative in a political sense (i.e., Rousseau's Social Contract Theory that all men were born free heavily contributed to the French Revolution). Art historians relate The Sleep of Reason Produces Monsters to historical events that occurred after its publication, such as the World Wars and the Holocaust, that represented an utter lack of reason "...on a modern industrial scale, all condemning our unwitting slumber".
Technical aspects
is notable for its use of aquatint, a printing technique that falls under the category of intaglio printing. Intaglio printing is characterized by the artist applying ink to the grooves of the matrix (i.e., the surface from which a print is made), allowing for intricate lines and refined tonality. According to William M. Ivins Jr., the first official Curator of Prints at the Metropolitan Museum of Art, "every intaglio print in which the lines are laid in a formal manner is an engraving, and every one in which they are laid freely is an etching," thus clarifying that the series falls under the broad category of "etchings". To produce an aquatint, the image itself is formed by applying a layer of resin (or a substitute of asphalt or bitumen) using one of two technical methods. An artist may allow the resin to settle on the plate as a dry dust by inserting the printing plate at the bottom of a box wherein the dust has been distributed. The printing plate is then heated so that each grain of resin dust melts and adheres to the metal. The alternative method is to dissolve the resin or asphalt in alcohol, and then pour this solution over the printing plate. The alcohol will then evaporate, leaving a thin film of resin which will dry on the plate. The plate is then immersed in acid, which etches the metal in the gaps around the grains of resin. The dust is then cleaned off the plate, to which ink is applied; the ink penetrates the etched depressions, and when the plate is printed, it creates a network of thin etched lines. This process produces a single tone, but the density of the tone varies depending on how finely the dust was ground and how thickly it covered the plate.
See also
List of works by Francisco Goya
References
External links
Schaefer, Sarah C. Goya's The Sleep of Reason Produces Monsters . smARThistory. Khan Academy.
Nyu.edu, The Sleep of Reason
1799 prints
18th-century etchings
Bats in popular culture
Owls in art
Cats in art
Prints by Francisco Goya
Philosophical phrases
1790s neologisms
1790s quotations
Sleep | The Sleep of Reason Produces Monsters | [
"Biology"
] | 2,653 | [
"Behavior",
"Sleep"
] |
17,583,286 | https://en.wikipedia.org/wiki/Farmers%20Bank%20Building%20%28Pittsburgh%29 | The Farmers Bank Building was a 27-story, skyscraper in Pittsburgh, Pennsylvania completed in 1902 and demolished on May 25, 1997. The University of Pittsburgh's online digital library states the building was constructed in 1903 and had 24 stories. To a generation of Pittsburgh sports fans the building is well remembered for being resurfaced in the mid 1960s in a failed rehabilitation but also fondly for a 15 story high mural of Roberto Clemente, Bill Mazeroski, Jack Lambert, Mean Joe Greene and Mario Lemieux completed in 1992 by Judy Penzer, who was killed in the crash of TWA Flight 800 four years later. For the five years the mural existed it was often the centerpiece for national networks cutting to or from games while they were in town for sporting events.
Rockwell International owned the building starting in the mid-1960s and used it as its global headquarters, selling it in early 1972 and consolidating its headquarters staff in the U.S. Steel Tower blocks away.
The building was imploded by Controlled Demolition, Inc. on the afternoon of May 25, 1997. In its place, a low-rise department store named Lazarus was built on the site. That building has since been extensively redesigned and now operates as a condominium development named Piatt Place.
See also
List of tallest buildings in Pittsburgh
References
1902 establishments in Pennsylvania
1997 disestablishments in Pennsylvania
Office buildings completed in 1902
Buildings and structures demolished in 1997
Skyscraper office buildings in Pittsburgh
Demolished buildings and structures in Pittsburgh
Former skyscrapers
Buildings and structures demolished by controlled implosion | Farmers Bank Building (Pittsburgh) | [
"Engineering"
] | 317 | [
"Buildings and structures demolished by controlled implosion",
"Architecture"
] |
17,583,514 | https://en.wikipedia.org/wiki/Charles%20E.%20Raven | Charles Earle Raven (4 July 1885 – 8 July 1964) was an English theologian and Anglican priest. He was Regius Professor of Divinity at Cambridge University (1932–1950) and Master of Christ's College, Cambridge (1939–1950). His works have been influential in the history of science publishing on the positive effects that theology has had upon modern science.
Career
Raven was born in Paddington, London on 4 July 1885, and was educated at Uppingham School. He obtained an open classical scholarship at Gonville and Caius College, Cambridge, and then became lecturer in divinity, fellow and dean of Emmanuel College, Cambridge. In 1932, he was elected Regius Professor of Divinity at Cambridge, a position he held until 1950. He was Master of Christ's College, Cambridge (1939–1950).
He was a clergyman in the Church of England, and attained the rank of canon. During the First World War he served as a chaplain to the forces and what he witnessed led him to take a pacifist position, a subject on which he wrote extensively for the rest of his life. As a pacifist, he was an active supporter of the Peace Pledge Union and the Fellowship of Reconciliation.
He first married Margaret Ermyntrude Buchanan Wollaston in 1910, with whom he had four children. Raven was the father of John Raven, the classical scholar and botanist, and grandfather of Andrew Raven and Sarah Raven.
His third marriage was to Hélène Jeanty, a Belgian widow whose husband had been killed by the occupying Germans in World War II. They met while she was working for the World Council of Churches (WCC). They worked together on reconciliation between students of different races, a continuation of her WCC work helping displaced Jews and Germans. She outlived Raven, dying on 9 October 1990 and, continuing the charitable work during her lifetime, left £150,000 to Christ's College to support medical students from overseas.
Raven was the Gifford Lecturer for 1950–1952 in Natural Religion and Christian Theology, at Edinburgh University. He was president of the Field Studies Council from 1953 to 1957 and of the Botanical Society of the British Isles from 1951 to 1955. He won the James Tait Black Award in 1947 for his book English Naturalists from Neckam to Ray.
Some of his writings have been described as an early example of ecotheology.
Evolution
Raven was an advocate of non-Darwinian evolutionary theories such as Lamarckism. He also supported the theistic evolution of Pierre Teilhard de Chardin.
Historian Peter J. Bowler has written that Raven's book The Creator Spirit, "outlined the case for a nonmaterialistic biology as the foundation for a renewed natural theology."
List of selected publications
What think ye of Christ? (1916)
Christian Socialism, 1848-1854 (1920)
Apollinarianism: An Essay on the Christology of the Early Church (1923)
In Praise of Birds (1925)
The Creator Spirit (1927)
Women and the Ministry (1929)
A Wanderer's Way (1929)
The Life and Teaching of Jesus Christ (1933)
Science, Religion, and the Future, a course of eight lectures (1943)
Alex Wood: the man and his message (1952)
The Theological Basis of Christian Pacifism. London: The Fellowship of Reconciliation (1952)
Natural Religion and Christian Theology (1953)
Science, Medicine and Morals: A Survey and a Suggestion (1959)
Paul and the Gospel of Jesus (1960)
Teilhard de Chardin: Scientist and Seer (1962)
See also
Relationship between religion and science
References
Footnotes
Bibliography
Further reading
External links
1885 births
1964 deaths
20th-century Anglican theologians
20th-century Church of England clergy
20th-century English Anglican priests
20th-century English male writers
20th-century English non-fiction writers
20th-century English theologians
20th-century evangelicals
Academics from London
Alumni of Gonville and Caius College, Cambridge
Anglican chaplains
Anglican clergy from London
Anglican pacifists
Anglican socialists
Anglican writers
Christian socialist theologians
Church of England priests
Ecotheology
English Anglican theologians
English Christian pacifists
English Christian socialists
English Evangelical writers
English military chaplains
Evangelical Anglican clergy
Evangelical Anglican theologians
Evangelical pastors
Fellows of Emmanuel College, Cambridge
British historians of science
Honorary chaplains to the King
Lamarckism
Masters of Christ's College, Cambridge
People from Paddington
Regius Professors of Divinity (University of Cambridge)
Theistic evolutionists
Vice-chancellors of the University of Cambridge
Writers about religion and science
Writers from the City of Westminster | Charles E. Raven | [
"Biology"
] | 914 | [
"Obsolete biology theories",
"Biology theories",
"Lamarckism",
"Non-Darwinian evolution",
"Theistic evolutionists"
] |
17,583,603 | https://en.wikipedia.org/wiki/Macrophage-activating%20factor | A macrophage-activating factor (MAF) is a lymphokine or other receptor based signal that primes macrophages towards cytotoxicity to tumors, cytokine secretion, or clearance of pathogens. Similar molecules may cause development of an inhibitory, regulatory phenotype. A MAF can also alter the ability of macrophages to present MHC I antigen, participate in Th responses, and/or affect other immune responses.
MAFs act typically in combination to produce a specific phenotype.
Macrophage activated phenotypes
Macrophages inherently display tissue and environment-dependent plasticity. In addition, the phenotypes of the macrophages in a certain environment play a fundamental role in determining the immune activity and response within the tissue.
Depending on the combination of MAFs signaling to the macrophage, the macrophage’s activated phenotype becomes one of three major categories: classically activated, wound healing, or regulatory. Regulatory-phenotype macrophages have only recently been recognized as an important contributor to tissue microenvironments.
Tumor-associated macrophages may be any of these types, and they have been found to be important players in the tumor microenvironment. Analysis of the macrophage population and signaling in a tumor may provide useful clinical data.
Clarifications on terminology
Macrophages have been classified as M1 or M2 depending on the adaptive immune response that elicited the phenotype: Th1 or Th2 respectively.
The phrase 'alternatively activated macrophage' is used to refer to M2 macrophages.
Regulatory macrophages do not fit into the M1/M2 classification system, and they display different markers.
Classically activated macrophages
After receiving signaling from both IFNγ and TNF, macrophages acquire a phenotype with higher activity against both pathogens and tumor cells. They also secrete inflammatory cytokines. IFNγ signaling can initially originate from Natural Killer (NK) cells, but adaptive immune cells are required to sustain a population of classically activated macrophages.
Toll-like receptor agonists may also cause macrophage activation.
Wound healing macrophages
Interleukin 4, secreted by granulocytes after tissue damage or by adaptive immune cells within a Th2 response, causes macrophages to secrete minimal amounts of pro-inflammatory cytokines and to have lower activity against intracellular pathogens. They also promote extracellular matrix synthesis via production of ornithine, via arginase; this is used as a precursor for extracellular matrix components. The overall result is a macrophage population that promotes wound healing.
The specific roles macrophages play in the Th2 response are still under investigation.
Regulatory macrophages
Glucocorticoids can contribute to the development of regulatory macrophages. These macrophages produce Interleukin 10 and inhibit immune system response (See below for Effect on cancer). Tumor-associated macrophages may contain a large population of regulatory macrophages.
Effect on cancer
Initially, MAFs were thought to increase a macrophage’s cytotoxic response, allowing enhanced clearance of the tumor cells. However, they also have wider ranging effects. Chronic inflammation associated with activated macrophages may lead to the development of neoplasia, such as those found surrounding tuberculosis scars.
Dysregulation of macrophage activation may cause increased inflammation and eventual neoplasia.
Moreover, macrophages infiltrating the tumor microenvironment can transition towards a regulatory phenotype. Regulatory macrophages produce Interleukin 10, which can inhibit cytotoxic responses of other lymphocytes to cancer cell antigens. The stromal reaction surrounding a tumor, as well as prostaglandins and hypoxia may play a role in this transition.
Epithelial-mesenchymal transition has been found to be influenced by all types of macrophages, which cause both pro and anti-inflammatory responses that can promote EMT.
Non-cytokine examples of macrophage-activating factors
Pathogenic antigens can bind to toll-like receptors that stimulate macrophage activation and response. Examples include heat shock proteins released during apoptosis, and bacterial lipopolysaccharide.
Examples
Interferon-gamma
Interleukin 4
TNF alpha
CD36
Miscellaneous
It has been suggested that MAF can be formed by probiotic bacteria in a yoghurt medium. This probiotic mixture has been found to be helpful in various immune disturbances including ME/CFS.
References
External links
Cytokines
Macrophages | Macrophage-activating factor | [
"Chemistry"
] | 971 | [
"Cytokines",
"Signal transduction"
] |
17,584,701 | https://en.wikipedia.org/wiki/Arithmetic%20dynamics | Arithmetic dynamics is a field that amalgamates two areas of mathematics, dynamical systems and number theory. Part of the inspiration comes from complex dynamics, the study of the iteration of self-maps of the complex plane or other complex algebraic varieties. Arithmetic dynamics is the study of the number-theoretic properties of integer, rational, -adic, or algebraic points under repeated application of a polynomial or rational function. A fundamental goal is to describe arithmetic properties in terms of underlying geometric structures.
Global arithmetic dynamics is the study of analogues of classical diophantine geometry in the setting of discrete dynamical systems, while local arithmetic dynamics, also called p-adic or nonarchimedean dynamics, is an analogue of complex dynamics in which one replaces the complex numbers by a -adic field such as or and studies chaotic behavior and the Fatou and Julia sets.
The following table describes a rough correspondence between Diophantine equations, especially abelian varieties, and dynamical systems:
Definitions and notation from discrete dynamics
Let be a set and let be a map from to itself. The iterate of with itself times is denoted
A point is periodic if for some .
The point is preperiodic if is periodic for some .
The (forward) orbit of is the set
Thus is preperiodic if and only if its orbit is finite.
Number theoretic properties of preperiodic points
Let be a rational function of degree at least two with coefficients in . A theorem of Douglas Northcott says that has only finitely many -rational preperiodic points, i.e., has only finitely many preperiodic points in . The uniform boundedness conjecture for preperiodic points of Patrick Morton and Joseph Silverman says that the number of preperiodic points of in is bounded by a constant that depends only on the degree of .
More generally, let be a morphism of degree at least two defined over a number field . Northcott's theorem says that has only finitely many preperiodic points in
, and the general Uniform Boundedness Conjecture says that the number of preperiodic points in
may be bounded solely in terms of , the degree of , and the degree of over .
The Uniform Boundedness Conjecture is not known even for quadratic polynomials over the rational numbers . It is known in this case that cannot have periodic points of period four, five, or six, although the result for period six is contingent on the validity of the conjecture of Birch and Swinnerton-Dyer. Bjorn Poonen has conjectured that cannot have rational periodic points of any period strictly larger than three.
Integer points in orbits
The orbit of a rational map may contain infinitely many integers. For example, if is a polynomial with integer coefficients and if is an integer, then it is clear that the entire orbit consists of integers. Similarly, if is a rational map and some iterate is a polynomial with integer coefficients, then every -th entry in the orbit is an integer. An example of this phenomenon is the map , whose second iterate is a polynomial. It turns out that this is the only way that an orbit can contain infinitely many integers.
Theorem. Let be a rational function of degree at least two, and assume that no iterate of is a polynomial. Let . Then the orbit contains only finitely many integers.
Dynamically defined points lying on subvarieties
There are general conjectures due to Shouwu Zhang
and others concerning subvarieties that contain infinitely many periodic points or that intersect an orbit in infinitely many points. These are dynamical analogues of, respectively, the Manin–Mumford conjecture, proven by Michel Raynaud, and the Mordell–Lang conjecture, proven by Gerd Faltings. The following conjectures illustrate the general theory in the case that the subvariety is a curve.
Conjecture. Let be a morphism and let be an irreducible algebraic curve. Suppose that there is a point such that contains infinitely many points in the orbit . Then is periodic for in the sense that there is some iterate of that maps to itself.
p-adic dynamics
The field of -adic (or nonarchimedean) dynamics is the study of classical dynamical questions over a field that is complete with respect to a nonarchimedean absolute value. Examples of such fields are the field of -adic rationals and the completion of its algebraic closure . The metric on and the standard definition of equicontinuity leads to the usual definition of the Fatou and Julia sets of a rational map . There are many similarities between the complex and the nonarchimedean theories, but also many differences. A striking difference is that in the nonarchimedean setting, the Fatou set is always nonempty, but the Julia set may be empty. This is the reverse of what is true over the complex numbers. Nonarchimedean dynamics has been extended to Berkovich space, which is a compact connected space that contains the totally disconnected non-locally compact field .
Generalizations
There are natural generalizations of arithmetic dynamics in which and are replaced by number fields and their -adic completions. Another natural generalization is to replace self-maps of or with self-maps (morphisms) of other affine or projective varieties.
Other areas in which number theory and dynamics interact
There are many other problems of a number theoretic nature that appear in the setting of dynamical systems, including:
dynamics over finite fields.
dynamics over function fields such as .
iteration of formal and -adic power series.
dynamics on Lie groups.
arithmetic properties of dynamically defined moduli spaces.
equidistribution and invariant measures, especially on -adic spaces.
dynamics on Drinfeld modules.
number-theoretic iteration problems that are not described by rational maps on varieties, for example, the Collatz problem.
symbolic codings of dynamical systems based on explicit arithmetic expansions of real numbers.
The Arithmetic Dynamics Reference List gives an extensive list of articles and books covering a wide range of arithmetical dynamical topics.
See also
Arithmetic geometry
Arithmetic topology
Combinatorics and dynamical systems
Arboreal Galois representation
Notes and references
Further reading
Lecture Notes on Arithmetic Dynamics Arizona Winter School, March 13–17, 2010, Joseph H. Silverman
Chapter 15 of A first course in dynamics: with a panorama of recent developments, Boris Hasselblatt, A. B. Katok, Cambridge University Press, 2003,
External links
The Arithmetic of Dynamical Systems home page
Arithmetic dynamics bibliography
Analysis and dynamics on the Berkovich projective line
Book review of Joseph H. Silverman's "The Arithmetic of Dynamical Systems", reviewed by Robert L. Benedetto
Dynamical systems
Algebraic number theory | Arithmetic dynamics | [
"Physics",
"Mathematics"
] | 1,387 | [
"Recreational mathematics",
"Arithmetic dynamics",
"Mechanics",
"Algebraic number theory",
"Number theory",
"Dynamical systems"
] |
17,584,743 | https://en.wikipedia.org/wiki/Oral%20and%20maxillofacial%20pathology | Oral and maxillofacial pathology refers to the diseases of the mouth ("oral cavity" or "stoma"), jaws ("maxillae" or "gnath") and related structures such as salivary glands, temporomandibular joints, facial muscles and perioral skin (the skin around the mouth). The mouth is an important organ with many different functions. It is also prone to a variety of medical and dental disorders.
The specialty oral and maxillofacial pathology is concerned with diagnosis and study of the causes and effects of diseases affecting the oral and maxillofacial region. It is sometimes considered to be a specialty of dentistry and pathology. Sometimes the term head and neck pathology is used instead, which may indicate that the pathologist deals with otorhinolaryngologic disorders (i.e. ear, nose and throat) in addition to maxillofacial disorders. In this role there is some overlap between the expertise of head and neck pathologists and that of endocrine pathologists.
Diagnosis
The key to any diagnosis is thorough medical, dental, social and psychological history as well as assessing certain lifestyle risk factors that may be involved in disease processes. This is followed by a thorough clinical investigation including extra-oral and intra-oral hard and soft tissues.
It is sometimes the case that a diagnosis and treatment regime are possible to determine from history and examination, however it is good practice to compile a list of differential diagnoses. Differential diagnosis allows for decisions on what further investigations are needed in each case.
There are many types of investigations in diagnosis of oral and maxillofacial diseases, including screening tests, imaging (radiographs, CBCT, CT, MRI, ultrasound) and histopathology (biopsy).
Biopsy
A biopsy is indicated when the patient's clinical presentation, past history or imaging studies do not allow a definitive diagnosis. A biopsy is a surgical procedure that involves the removal of a piece of tissue sample from the living organism for the purpose of microscopic examination. In most cases, biopsies are carried out under local anaesthesia. Some biopsies are carried out endoscopically, others under image guidance, for instance ultrasound, computed tomography (CT) or magnetic resonance imaging (MRI) in the radiology suite. Examples of the most common tissues examined by means of a biopsy include oral and sinus mucosa, bone, soft tissue, skin and lymph nodes.
Types of biopsies typically used for diagnosing oral and maxillofacial pathology are:
Excisional biopsy: A small lesion is totally excised. This method is preferred if the lesions are approximately 1 cm or less in diameter, clinically and seemingly benign and surgically accessible. Large lesions which are more diffused and dispersed in nature or those which are seemed to be more clinically malignant are not conducive to total removal.
Incisional biopsy: A small portion of the tissue is removed from an abnormal-looking area for examination. This method is useful in dealing with large lesions. If the abnormal region is easily accessed, the sample may be taken at the doctor's office. If the tumour is deeper inside the mouth or throat, the biopsy may need to be performed in an operating room. General anaesthesia is administered to eliminate any pain.
Exfoliative cytology: A suspected area is gently scraped to collect a sample of cells for examination. These cells are placed on a glass slide and stained with dye, so that they can be viewed under a microscope. If any cells appear abnormal, a deeper biopsy will be performed.
Diseases
Oral and maxillofacial pathology can involve many different types of tissues of the head. Different disease processes affect different tissues within this region with various outcomes. A great many diseases involve the mouth, jaws and orofacial skin. The following list is a general outline of pathologies that can affect oral and maxillofacial region; some are more common than others. This list is by no means exhaustive.
Congenital
Cleft lip and palate
Cleft lip and palate is one of the most common occurring multi-factorial congenital disorder occurring in 1 in 500–1000 live births in several forms. The most common form is combined cleft lip and palate and it accounts for approximately 50% of cases, whereas isolated cleft lip concerns 20% of the patients.
People with cleft lip and palate malformation tend to be less social and report lower self-esteem, anxiety and depression related to their facial malformation. One of the major goals in the treatment of patients with cleft is to enhance social acceptance by surgical reconstruction.
A cleft lip is an opening of the upper lip, mainly due to the failure of fusion of the medial nasal processes with the palatal processes; a cleft palate is the opening of the soft and hard palate in the mouth, which is due to the failure of the palatal shelves to fuse together.
The palate's main function is to demarcate the nasal and oral cavity, without which the patient will have problems with swallowing, eating and speech, thus affecting the quality of life and in some cases certain functions.
Some examples include food going up into the nasal cavity during swallowing as the soft palate is not present to close the cavity during the process. Speech is also affected as the nasal cavity is a source of resonance during speech and failure to manipulate spaces in the cavities will result in the lack of ability to produce certain consonants in audible language.
Macroglossia
Macroglossia is a rare condition, categorised by tongue enlargement which will eventually create a crenated border in relation to the embrasures between the teeth.
Hereditary causes include vascular malformations, Down syndrome, Beckwith–Wiedemann syndrome, Duchenne muscular dystrophy, and Neurofibromatosis type I.
Acquired causes include carcinoma, lingual thyroid, myxedema, and amyloidosis.
Consequences may include noisy breaths – airway obstruction in severe cases, drooling, difficulty eating, lisping speech, open bite, and protruding tongue, which may ulcerate and undergo necrosis.
For mild cases, surgical treatment is not mandatory but if speech is affected, speech therapy may be useful. Reduction glossectomy may be required for severe cases.
Ankyloglossia
Ankyloglossia (also known as tongue-tie) may decrease the mobility of the tongue tip and is caused by an unusually short, thick lingual frenulum, a membrane connecting the underside of the tongue to the floor of the mouth.
Stafne defect
Stafne defect is a depression of the mandible, most commonly located on the lingual surface (the side nearest the tongue).
Torus palatinus
Torus palatinus is a bony protrusion on the palate, usually present on the midline of the hard palate.
Torus mandibularis
Torus mandibularis is a bony growth in the mandible along the surface nearest to the tongue. Mandibular tori usually are present near the premolars and above the location on the mandible of the mylohyoid muscle attachment.
Eagle syndrome
Eagle syndrome is a condition where there is an abnormal ossification of the stylohyoid ligament. This leads to an increase in the thickness and the length of the stylohyoid process and the ligament. Pain is felt due to the pressure applied to the internal jugular vein. Eagle syndrome occurs due to elongation of the styloid process or calcification of the stylohyoid ligament. However, the cause of the elongation has not been known clearly. It could occur spontaneously or could arise since birth. Usually normal stylohyoid process is 2.5–3 cm in length, if the length is longer than 3 cm, it is classified as an elongated stylohyoid process.
Acquired
Infective
Bacterial
(Plaque-induced) gingivitis—A common periodontal (gum) disease is gingivitis. Periodontal refers to the area the infection affects, which include the teeth, gums, and tissues surrounding the teeth. Bacteria cause inflammation of the gums which become red, swollen and can bleed easily. The bacteria along with mucus form a sticky colorless substance called plaque which harbours the bacteria. Plaque that is not removed by brushing and flossing hardens to form tartar that brushing does not clean. Smoking is a major risk factor. Treatment of gingivitis is dependent on how severe and how far the disease has progressed. If the disease is not too severe it is possible to treat it with chlorhexidine rinse and brushing with fluoride toothpaste to kill the bacteria and remove the plaque, but once the infection has progressed antibiotics may be needed to kill the bacteria.
Periodontitis—When gingivitis is not treated it can advance to periodontitis, when the gums pull away from the teeth and form pockets that harbor the bacteria. Bacterial toxins and the body's natural defenses start to break down the bone and connective tissues. The tooth may eventually become loose and have to be removed.
Scarlet fever is caused by a particular streptococci species, Streptococci Pyogenes, and is classified be a severe form of bacterial sore throat. The condition involves the release of pyrogenic and erythrogenic endotoxins from the immune system. It starts as tonsilitis and pharyngitis before involving the soft palate and the tongue. It usually occurs in children where a fever occurs and an erythematous rash develops on the face and spreads to most part of the body. If not treated, late stages of this condition may include a furred, raw, red tongue. Treatment options include penicillin and the prognosis is generally excellent.
Viral
Herpes simplex (infection with herpes simplex virus, or HSV) is very common in the mouth and lips. This virus can cause blisters and sores around the mouth (herpetic gingivostomatitis) and lips (herpes labialis). HSV infections tend to recur periodically. Although many people get infected with the virus, only 10% actually develop the sores. The sores may last anywhere from 3–10 days and are very infectious. Some people have recurrences either in the same location or at a nearby site. Unless the individual has an impaired immune system, e.g., owing to HIV or cancer-related immune suppression, recurrent infections tend to be mild in nature and may be brought on by stress, sun, menstrual periods, trauma or physical stress.
Mumps of the salivary glands is a viral infection of the parotid glands. This results in painful swelling at the sides of the mouth in both adults and children, which leads to a sore throat, and occasionally pain in chewing. The infection is quite contagious. Mumps is prevented through vaccination in infancy with the measles, mumps, and rubella (MMR) vaccination and subsequent boosters. There is no specific treatment for mumps except for hydration and painkillers with complete recovery ranging from 5–10 days. Sometimes mumps can cause inflammation of the brain, pancreatitis, testicular swelling or hearing loss.
Fungal
Oral candidiasis is by far the most common fungal infection that occurs in the mouth. It usually occurs in immunocompromised individuals. Individuals who have undergone a transplant, HIV, cancer or use corticosteroids commonly develop candida of the mouth and oral cavity. Other risk factors are dentures and tongue piercing. The typical signs are a white patch that may be associated with burning, soreness, irritation or a white cheesy-like appearance. Once the diagnosis is made, candida can be treated with a variety of anti fungal drugs.
Traumatic
Chemical, thermal, mechanical or electrical trauma to the oral soft tissues can cause traumatic oral ulceration.
Autoimmune
Sjögren syndrome is an autoimmune chronic inflammatory disorder characterised by some of the body's own immune cells infiltrating and destroying lacrimal and salivary glands (and other exocrine glands). There are two types of Sjögren syndrome: primary and secondary. In primary Sjögren syndrome (pSS) individuals have dry eyes (keratoconjunctivitis sicca) and a dry mouth (xerostomia). Based on a meta-analysis, the prevalence of pSS worldwide is estimated to 0.06%, with 90% of the patients being female. In secondary Sjögren syndrome (sSS), individuals have a dry mouth, dry eyes and a connective tissue disorder such as rheumatoid arthritis (prevalence 7% in the UK), systemic lupus erythematosus (prevalence 6.5%–19%) and systemic sclerosis (prevalence 14%–20.5%). Additional features and symptoms include:
Erythema and lobulation of the tongue
Oral discomfort
Difficulty in swallowing and talking
Altered taste
Poor retention of dentures (if worn)
Oral fungal and bacterial infections
Salivary glands swelling
Dryness of skin; nose; throat; vagina
Peripheral neuropathies
Pulmonary; thyroid; and renal disorders;
Arthralgias and myalgias;
Tests used to diagnose Sjögren syndrome include:
tear break-up time and Schirmer's tests
a minor salivary gland biopsy taken from the lip
blood tests
salivary flow rate
There is no cure for Sjögren syndrome; however, there are treatments used to help with the associated symptoms.
Eye care: artificial tears, moisture chamber spectacles, punctal plugs, pilocarpine medication
Mouth care: increase oral intake, practice good oral hygiene, use sugar free gum (to increase saliva flow), regular use of mouth rinses, pilocarpine medication, reduce alcohol intake and smoking cessation. Saliva substitutes are also available as a spray, gel, gum or in the form of a medicated sweet
Dry skin: creams, moisturising soaps
Vaginal dryness: lubricant, oestrogen creams, hormonal replacement therapy
Muscle and joint pains: Non-steroidal anti-inflammatory drugs
Complications of Sjögren syndrome include ulcers that can develop on the surface of the eyes if the dryness is not treated. These ulcers can then cause more worrying issues such as loss of eyesight and life-long damage. Individuals with Sjögren syndrome have a slightly increased risk of developing non-Hodgkin lymphoma, a type of cancer. Other conditions such as peripheral neuropathy, Raynaud's phenomenon, kidney problems, underactive thyroid gland and irritable bowel syndrome have been linked to Sjögren syndrome.
Inflammatory
Angioedema
Neoplastic
Oral cancer may occur on the lips, tongue, gums, floor of the mouth or inside the cheeks. The majority of cancers of the mouth are squamous cell carcinoma. Oral cancers are usually painless in the initial stages or may appear like an ulcer. Causes of oral cancer include smoking, excessive alcohol consumption, exposure to sunlight (lip cancer), chewing tobacco, infection with human papillomavirus, and hematopoietic stem cell transplantation. The earlier the oral cancer is diagnosed, the better the chances for full recovery. Persistent suspicious masses or ulcers on the mouth should always be examined. Diagnosis is usually made with a biopsy; treatment depends on the exact type of cancer, where it is situated, and extent of spreading.
Environmental
Unknown
There are many oral and maxillofacial pathologies which are not fully understood.
Burning mouth syndrome (BMS) is a disorder where there is a burning sensation in the mouth that has no identifiable medical or dental cause. The disorder can affect anyone but tends to occur most often in middle-aged women. BMS has been hypothesized to be linked to a variety of factors such as the menopause, dry mouth (xerostomia) and allergies. BMS usually lasts for several years before disappearing for unknown reasons. Other features of this disorder include anxiety, depression and social isolation. There is no cure for this disorder and treatment includes use of hydrating agents, pain medications, vitamin supplements or the usage of antidepressants.
Aphthous stomatitis is a condition where ulcers (canker sores) appear on the inside of the mouth, lips and on tongue. Most small canker sores disappear within 10–14 days. Canker sores are most common in young and middle aged individuals. Sometimes individuals with allergies are more prone to these sores. Besides an awkward sensation, these sores can also cause pain or tingling or a burning sensation. Unlike herpes sores, canker sores are always found inside the mouth and are usually less painful. Good oral hygiene helps but topical corticosteroids may be necessary.
Migratory stomatitis is a condition that involves the tongue and other oral mucosa. The common migratory glossitis (geographic tongue) affects the anterior two thirds of the dorsal and lateral tongue mucosa of 1% to 2.5% of the population, with one report of up to 12.7% of the population. The tongue is often fissured, especially. in elderly individuals. In the American population, a lower prevalence was reported among Mexican Americans (compared with Caucasians and African Americans) and cigarette smokers. When other oral mucosa, beside the dorsal and lateral tongue, are involved, the term migratory stomatitis (or ectopic geographic tongue) is preferred. In this condition, lesions infrequently involve also the ventral tongue and buccal or labial mucosa. They are rarely reported on the soft palate and floor of the mouth.
Specialty
Oral and maxillofacial pathology, previously termed oral pathology, is a speciality involved with the diagnosis and study of the causes and effects of diseases affecting the oral and maxillofacial regions (i.e. the mouth, the jaws and the face). It can be considered a speciality of dentistry and pathology. Oral pathology is a closely allied speciality with oral and maxillofacial surgery and oral medicine.
The clinical evaluation and diagnosis of oral mucosal diseases are in the scope of oral and maxillofacial pathology specialists and oral medicine practitioners, both disciplines of dentistry.
When a microscopic evaluation is needed, a biopsy is taken, and microscopically observed by a pathologist. The American Dental Association uses the term oral and maxillofacial pathology, and describes it as "the specialty of dentistry and pathology which deals with the nature, identification, and management of diseases affecting the oral and maxillofacial regions. It is a science that investigates the causes, processes and effects of these diseases."
In some parts of the world, oral and maxillofacial pathologists take on responsibilities in forensic odontology.
Geographic variation
United Kingdom
There are approximately 30 consultant oral and maxillofacial pathologists in the UK. A dental degree is mandatory, but a medical degree is not. The shortest pathway to becoming an oral pathologist in the UK is completion of two years' general professional training and then five years in a diagnostic histopathology training course. After passing the required Royal College of Pathologists exams and gaining a Certificate of Completion of Specialist Training, the trainee is entitled to apply for registration as a specialist. Many oral and maxillofacial pathologists in the UK are clinical academics, having undertaken a PhD either prior to or during training. Generally, oral and maxillofacial pathologists in the UK are employed by dental or medical schools and undertake their clinical work at university hospital departments.
New Zealand
There are five practising oral pathologists in New Zealand (). Oral pathologists in New Zealand also take part in forensic evaluations.
See also
Tongue disease
Salivary gland disease
Head and neck cancer
Oral surgery
Tooth pathology
References
Further reading
External links
British Society of Oral & Maxillo-facial Pathologists Website
Academy of Oral and Maxillofacial Pathology Website
Main
Pathology | Oral and maxillofacial pathology | [
"Biology"
] | 4,214 | [
"Pathology"
] |
17,585,131 | https://en.wikipedia.org/wiki/Killer%20yeast | A killer yeast is a yeast, such as Saccharomyces cerevisiae, which is able to secrete one of a number of toxic proteins which are lethal to susceptible cells. These "killer toxins" are polypeptides that kill sensitive cells of the same or related species, often functioning by creating pores in target cell membranes. These yeast cells are immune to the toxic effects of the protein due to an intrinsic immunity. Killer yeast strains can be a problem in commercial processing because they can kill desirable strains. The killer yeast system was first described in 1963. Study of killer toxins helped to better understand the secretion pathway of yeast, which is similar to those of more complex eukaryotes. It also can be used in treatment of some diseases, mainly those caused by fungi.
Saccharomyces cerevisiae
The best characterized toxin system is from yeast (Saccharomyces cerevisiae), which was found to spoil brewing of beer. In S. cerevisiae are toxins encoded by a double-stranded RNA virus, translated to a precursor protein, cleaved and secreted outside of the cells, where they may affect susceptible yeast. There are other killer systems in S. cerevisiae, such as KHR1 and KHS1 genes encoded on chromosomes IX and V, respectively.
RNA virus
The virus, L-A, is an icosahedral virus of S. cerevisiae comprising a 4.6 kb genomic segment and several satellite double-stranded RNA sequences, called M dsRNAs. The genomic segment encodes for the viral coat protein and a protein which replicates the viral genomes. The M dsRNAs encode the toxin, of which there are at least three variants in S. cerevisiae, and many more variants across all species.
L-A virus uses yeast Ski complex (super killer) and MAK (maintenance of killer) chromosomal genes for its preservation in the cell. The virus is not released into the environment. It spreads between cells during yeast mating. The family of Totiviridae in general helps M-type dsRNAs in a wide variety of yeasts.
Toxins
The initial protein product from translation of the M dsRNA is called the preprotoxin, which is targeted to the yeast secretory pathway. The preprotoxin is processed and cleaved to produce an α/β dimer, which is the active form of the toxin, and is released into the environment.
The two most studied variant toxins in S. cerevisiae are K1 and K28. There are numerous appearently unrelated M dsRNAs, their only similarity being their genome and preprotoxin organization.
K1 binds to the β-1,6-D-glucan receptor on the target cell wall, moves inside, and then binds to the plasma membrane receptor Kre1p. It forms a cation-selective ion channel in the membrane, which is lethal to the cell.
K28 uses the α-1,6-mannoprotein receptor to enter the cell, and utilizes the secretory pathway in reverse by displaying the endoplasmic reticulum HDEL signal. From the ER, K28 moves into the cytoplasm and shuts down DNA synthesis in the nucleus, triggering apoptosis.
Immunity
Sesti, Shih, Nikolaeva and Goldstein (2001) claimed that K1 inhibits the TOK1 membrane potassium channel before secretion, and although the toxin reenters through the cell wall it is unable to reactivate TOK1. However Breinig, Tipper and Schmitt (2002) showed that the TOK1 channel was not the primary receptor for K1, and that TOK1 inhibition does not confer immunity. Vališ, Mašek, Novotná, Pospíšek and Janderová (2006) experimented with mutants which produce K1 but do not have immunity to it, and suggested that cell membrane receptors were being degraded in the secretion pathway of immune cells, apparently due to the actions of unprocessed α chains.
Breinig, Sendzik, Eisfeld and Schmitt (2006) showed that K28 toxin is neutralized in toxin-expressing cells by the α chain in the cytosol, which has not yet been fully processed and still contains part of a γ chain attached to the C terminus. The uncleaved α chain neutralizes the K28 toxin by forming a complex with it.
Kluyveromyces lactis
Killer properties of Kluyveromyces lactis are associated with linear DNA plasmids, which have on their 5'end associated proteins, which enable them to replicate themselves, in a way similar to adenoviruses. It is an example of protein priming in DNA replication. MAK genes are not known. The toxin consists of three subunits, which are matured in golgi complex by signal peptidase and glycosylated.
The mechanism of action appears to be the inhibition of adenylate cyclase in sensitive cells. Affected cells are arrested in G1 phase and lose viability.
Other yeast
Other toxin systems are found in other yeasts:
Pichia and Williopsis
Hanseniaspora uvarum
Zygosaccharomyces bailii
Ustilago maydis: a smut fungus that produces killer toxin Kp4 family fungal killer toxins.
Debaryomyces hansenii
Use of toxins
The susceptibility to toxins varies greatly between yeast species and strains. Several experiments have made use of this to reliably identify strains. Morace, Archibusacci, Sestito and Polonelli (1984) used the toxins produced by 25 species of yeasts to differentiate between 112 pathogenic strains, based on their sensitivity to each toxin. This was extended by Morace et al. (1989) to use toxins to differentiate between 58 bacterial cultures. Vaughan-Martini, Cardinali and Martini (1996) used 24 strains of killer yeast from 13 species to find a resistance signature for each of 13 strains of S. cerevisiae which were used as starters in wine-making. It was shown that sensitivity to toxins could be used to discriminate between 91 strains of Candida albicans and 223 other Candida strains.
Others experimented with using killer yeasts to control undesirable yeasts. Palpacelli, Ciani and Rosini (1991) found that Kluyveromyces phaffii was effective against Kloeckera apiculata, Saccharomycodes ludwigii and Zygosaccharomyces rouxii – all of which cause problems in the food industry. Polonelli et al. (1994) used a killer yeast to vaccinate against C. albicans in rats. Lowes et al. (2000) created a synthetic gene for the toxin HMK normally produced by Williopsis mrakii, which they inserted into Aspergillus niger and showed that the engineered strain could control aerobic spoilage in maize silage and yoghurt. A toxin-producing strain of Kluyveromyces phaffii to control apiculate yeasts in wine-making. A toxin produced by Candida nodaensis was effective at preventing spoilage of highly salted food by yeasts.
Several experiments suggest that antibodies that mimic the biological activity of killer toxins have application as antifungal agents.
Killer yeasts from flowers of Indian medicinal plants were isolated and the effect of their killer toxin was determined on sensitive yeast cells as well as fungal pathogens. The toxin of Saccharomyces cerevisiae and Pichia kluyveri inhibited Dekkera anomala accumulating methylene blue cells on Yeast Extract Peptone Dextrose agar (pH 4.2) at 21°C. There was no inhibition of growth or competition between the yeast cells in the mixed population of S. cerevisiae isolated from Acalypha indica. S. cerevisiae and P. kluyveri were found to tolerate 50% and 40% glucose, while D. anomala tolerated 40% glucose. Both S. cerevisiae and P. kluyveri did not inhibit the growth of Aspergillus niger.
Control methods
Young and Yagiu (1978) experimented with methods of curing killer yeasts. They found that using a cycloheximine solution at 0.05 ppm was effective in eliminating killer activity in one strain of S. cerevisiae. Incubating the yeast at 37 °C eliminated activity in another strain. The methods were not effective at reducing toxin production in other yeast species. Many toxins are sensitive to pH levels; for example, K1 is permanently inactivated at pH levels over 6.5.
The greatest potential for control of killer yeasts appears to be the addition of the L-A virus and M dsRNA, or an equivalent gene, into the industrially desirable variants of yeast, so they achieve immunity to the toxin, and also kill competing strains.
See also
Yeast in winemaking
References
Further reading
Yeasts | Killer yeast | [
"Biology"
] | 1,911 | [
"Yeasts",
"Fungi"
] |
17,586,014 | https://en.wikipedia.org/wiki/Pedestrian%20village | A pedestrian village is a compact, pedestrian-oriented neighborhood or town with a mixed-use village center. Shared-use lanes for pedestrians and those using bicycles, Segways, wheelchairs, and other small rolling conveyances that do not use internal combustion engines. Generally, these lanes are in front of the houses and businesses, and streets for motor vehicles are always at the rear. Some pedestrian villages might be nearly car-free with cars either hidden below the buildings, or on the boundary of the village. Venice, Italy is essentially a pedestrian village with canals. Other examples of a pedestrian village include Giethoorn village located in the Dutch province of Overijssel, Netherlands, Mont-Tremblant Pedestrian Village located beside Mont-Tremblant, Quebec, Canada, and Culdesac Tempe in Tempe, Arizona.
The canal district in Venice, California, on the other hand, combines the front lane/rear street approach with canals and walkways, or just walkways.
See also
List of car-free islands
New Urbanism
Principles of intelligent urbanism
Urban vitality
Walkability
Walking audit
Walking city
Infrastructure:
References
External links
Pedestrian Villages website
World Carfree Network
Village Homes, Davis, California
Urban planning
Transportation planning
Neighbourhoods by type | Pedestrian village | [
"Engineering"
] | 257 | [
"Urban planning",
"Architecture"
] |
17,586,114 | https://en.wikipedia.org/wiki/3-Methoxytyramine | 3-Methoxytyramine (3-MT), also known as 3-methoxy-4-hydroxyphenethylamine, is a human trace amine and the major metabolite of the monoamine neurotransmitter dopamine. It is formed by the introduction of a methyl group to dopamine by the enzyme catechol-O-methyltransferase (COMT). 3-MT can be further metabolized by the enzyme monoamine oxidase (MAO) to form homovanillic acid (HVA), which is then typically excreted in the urine.
Occurrence
3-Methoxytyramine occurs naturally in the prickly pear cactus (genus Opuntia), and is in general widespread throughout the Cactaceae. It has also been found in crown gall tumors on Nicotiana sp.
In humans, 3-methoxytyramine is a trace amine that occurs as a metabolite of dopamine.
Biological activity
Originally thought to be physiologically inactive, 3-MT was subsequently found to act as an agonist of the rodent and human TAAR1. 3-MT can induce weak hyperlocomotion in mice and this effect is partially attenuated in TAAR1 knockout mice.
See also
Tyramine
3,4-Dimethoxyphenethylamine
References
Phenethylamines
Phenethylamine alkaloids
Phenols
TAAR1 agonists
Trace amines
Psychedelic phenethylamine carriers | 3-Methoxytyramine | [
"Chemistry"
] | 325 | [
"Alkaloids by chemical classification",
"Phenethylamine alkaloids"
] |
17,586,371 | https://en.wikipedia.org/wiki/2%2C3-Dihydroxy-3-methylpentanoic%20acid | 2,3-Dihydroxy-3-methylpentanoic acid is an intermediate in the metabolism of isoleucine.
Metabolism
2,3-Dihydroxy-3-methylpentanoate is synthesized by the action of acetolactate mutase with subsequent reduction from α-aceto-α-hydroxybutyrate through 3-hydroxy-2-keto-3-methylpentanoate:
α-aceto-α-hydroxybutyrate → 3-hydroxy-2-keto-3-methylpentanoate
3-hydroxy-2-keto-3-methylpentanoate + NAD(P)H → 2,3-dihydroxy-3-methylpentanoate + NAD(P)+
It is then processed by the action of dihydroxyacid dehydratase, which results in 2-keto-3-methylvalerate and water:
2,3-dihydroxy-3-methylpentanoate → 2-keto-3-methylvalerate + H2O
Transamination of 2-keto-3-methylvalerate yields isoleucine.
References
Alpha hydroxy acids
Vicinal diols
Beta hydroxy acids | 2,3-Dihydroxy-3-methylpentanoic acid | [
"Chemistry"
] | 270 | [
"Organic compounds",
"Organic compound stubs",
"Organic chemistry stubs"
] |
17,586,700 | https://en.wikipedia.org/wiki/George%20Edwards%20%28Australian%20politician%29 | George Bertrand Edwards (30 January 1855 – 4 February 1911) was an Australian politician. He was a member of the Australian House of Representatives representing the Division of South Sydney for the Free Trade Party from 1901 to 1906 and the Division of North Sydney for the Liberal Party from 1910 until his death in 1911.
Edwards was born and raised in Hobart, Tasmania, the son of a tobacconist and was educated at Christ College. He became a journalist with the Tasmanian Tribune at the age of 20. He later managed the new Hobart office of Launceston newspaper The Examiner 1882–83, then in 1884 briefly went to Sydney to run the Peacock Jam Company branch there, but returned to Hobart the next year to run the Launceston office of Hobart newspaper The Mercury. He married the eldest daughter of jam magnate George Peacock in October 1885. He later worked on the general staff of The Mercury, was chief Hansard reporter for two sessions of the Federal Council of Australasia and was editor of the Mercury-owned Tasmanian Mail weekly magazine in 1888–89.
Edwards then managed the Peacock Jam Company's Melbourne branch until purchasing the company's Sydney operations in 1894, subsequently operating that business in partnership with Herbert Peacock. He also purchased 60 acres of land adjoining Ku-ring-gai Chase National Park for a house and fruitgrowing operation. He was a supporter of free trade policies and an unsuccessful Free Trade candidate at the 1898 election.
In 1901, he contested the first federal election as the Free Trade candidate for South Sydney, and won, defeating state Labor leader James McGowen. His platform included support for a White Australia policy and a federal old age pension. In parliament, Edwards chaired the Decimal Coinage Commission and was a member of the Royal Commission on Navigation. Edwards was an early supporter of decimalisation and metrification, and moved several motions calling on Australia to adopt the metric system and a decimal currency. He retired at the 1906 election due to a mix of health concerns and business commitments. Peacock & Co (Edwards' Sydney operation) amalgamated with two other major jam manufacturers to form Henry Jones' Co-operative, Ltd. (later Henry Jones IXL) in early 1910, and later that year he returned to the House of Representatives as the Liberal member for North Sydney.
Edwards was killed when an acetylene gasometer exploded at his property in Turramurra on 4 February 1911. A mechanic named John Graham was also killed in the explosion, which was overheard by Edwards' daughter Annie. The explosion destroyed the brick structure in which the gasometer was housed, and the victims' bodies were found some distance from the gasometer, both with severe head injuries. A coronial inquiry returned a verdict of accidental death.
References
Free Trade Party members of the Parliament of Australia
Commonwealth Liberal Party members of the Parliament of Australia
Members of the Australian House of Representatives for South Sydney
Members of the Australian House of Representatives for North Sydney
Members of the Australian House of Representatives
1855 births
1911 deaths
Accidental deaths in New South Wales
Industrial accident deaths
Politicians from Hobart
Deaths from explosion
Colony of Tasmania people
Australian MPs 1901–1903
Australian MPs 1903–1906
Australian MPs 1910–1913 | George Edwards (Australian politician) | [
"Chemistry"
] | 633 | [
"Deaths from explosion",
"Explosions"
] |
13,617,834 | https://en.wikipedia.org/wiki/List%20of%20Schedule%20IV%20controlled%20substances%20%28U.S.%29 | This is the list of Schedule IV controlled substances in the United States as defined by the Controlled Substances Act. The following findings are required for substances to be placed in this schedule:
The drug or other substance has a low potential for abuse relative to the drugs or other substances in schedule III.
The drug or other substance has a currently accepted medical use in treatment in the United States.
Abuse of the drug or other substance may lead to limited physical dependence or psychological dependence relative to the drugs or other substances in schedule III.
The complete list of Schedule IV substances is as follows. The Administrative Controlled Substances Code Number and Federal Register citation for each substance is included.
Narcotics
Depressants
†Flunitrazepam has not been approved by the Food and Drug Administration for medical use, and is considered to be an illegal drug.
†Temazepam may require a specially coded prescription in certain States.
Lorcaserin
Stimulants
Others
See also
List of Schedule I controlled substances (U.S.)
List of Schedule II controlled substances (U.S.)
List of Schedule III controlled substances (U.S.)
List of Schedule V controlled substances (U.S.)
Notes
References
Controlled Substances Act
Drug-related lists | List of Schedule IV controlled substances (U.S.) | [
"Chemistry"
] | 249 | [
"Drug-related lists"
] |
13,617,924 | https://en.wikipedia.org/wiki/List%20of%20Schedule%20V%20controlled%20substances%20%28U.S.%29 | This is the list of Schedule V controlled substances in the United States as defined by the Controlled Substances Act. The following findings are required for substances to be placed in this schedule:
The drug or other substance has a low potential for abuse relative to the drugs or other substances in schedule IV.
The drug or other substance has a currently accepted medical use in treatment in the United States.
Abuse of the drug or other substance may lead to limited physical dependence or psychological dependence relative to the drugs or other substances in schedule IV.
The complete list of Schedule V substances is as follows. The Administrative Controlled Substances Code Number and Federal Register citation for each substance is included.
Opiates and opioids
Stimulants
Others
See also
List of Schedule I controlled substances (U.S.)
List of Schedule II controlled substances (U.S.)
List of Schedule III controlled substances (U.S.)
List of Schedule IV controlled substances (U.S.)
Notes
References
Controlled Substances Act
Drug-related lists | List of Schedule V controlled substances (U.S.) | [
"Chemistry"
] | 202 | [
"Drug-related lists"
] |
13,618,937 | https://en.wikipedia.org/wiki/Fault%20breccia | Fault breccia, or tectonic breccia, is a breccia (a rock type consisting of angular clasts) that was formed by tectonic forces.
Fault breccia is a tectonite formed by localized zone of brittle deformation (a fault zone) in a rock. Brecciation in fault zones influences fault zone hydrogeology in its interaction with groundwater and petroleum deposits.
Origin
Fault breccias are tectonites formed primarily by tectonic movement along a localized zone of brittle deformation (a fault zone) in a rock formation or province.
The grinding and milling occurring when the two sides of the fault zone moving along each other results in a material that is made of loose fragments. Because of this fragmentation fault zones are easily infiltrated by groundwater.
Secondary minerals such as calcite, epidote, quartz or talc can precipitate from the circulating groundwater filling the voids and cementing the rock. However, when the tectonic movement along the fault zone continues the cement itself can be fragmented leading to a new gouge material containing neoformed clasts.
Deeper in the Earth's crust, where temperatures and pressures are higher, the rocks in the fault zone can still brecciate, but they keep their internal cohesion. The resulting type of rock is called a cataclasite.
Properties
Fault breccia has no cohesion; it is normally an unconsolidated rock type, unless cementation took place at a later stage. Sometimes a distinction is made between fault gouge and fault breccia, the first has a smaller grain size.
Zones of fault breccia and fault gouge in rocks can be a hazard for the construction of tunnels and mines, as the non-cohesive zones form weak places in the rock where a tunnel can collapse more easily.
See also
Breccia
Cataclasite
Mylonite
Fault (geology)
References
Rocks
Tectonics
Breccias | Fault breccia | [
"Physics",
"Materials_science"
] | 404 | [
"Breccias",
"Fracture mechanics",
"Physical objects",
"Rocks",
"Matter"
] |
13,619,071 | https://en.wikipedia.org/wiki/Triisodontidae | Triisodontidae is an extinct, probably paraphyletic, or possibly invalid family of mesonychian placental mammals. Most triisodontid genera lived during the Paleocene in North America, but the genus Andrewsarchus (if it is a mesonychian, and not an artiodactyl) is known from the middle Eocene of Asia. Triisodontids were the first relatively large predatory mammals to appear in North America following the extinction of the non-bird dinosaurs. They differ from other mesonychian families in having less highly modified teeth.
Because of their comparatively simpler teeth, the triisodontids are regarded as basal mesonychids. A recent study found them to be a paraphyletic assemblage of stem-mesonychians.
References
Mesonychia
Eocene extinctions
Paleocene first appearances
Paraphyletic groups
Prehistoric mammal families | Triisodontidae | [
"Biology"
] | 190 | [
"Phylogenetics",
"Paraphyletic groups"
] |
13,619,556 | https://en.wikipedia.org/wiki/Effortfulness | In psychology, effortfulness is the subjective experience of exertion when performing an activity, especially the mental concentration and energy required. In many applications, effortfulness is simply reported by a patient, client, or experimental subject. There has been some work establishing an association among reported effortfulness and objective measures, such as in brain imaging. Effortfulness is used as a diagnostic indicator in medical and psychological diagnosis and assessment. It is also used as an indicator in psychological experimentation, especially in the field of memory.
In the study of aging, Patrick Rabbitt proposed an effortfulness hypothesis in the 1960s: that as their hearing became less acute with age, people would require additional effort to make out what was said and that this effort made it harder to remember it.
See also
Horme - in Greek mythology, a goddess personifying energetic activity
Laban movement analysis
References
Motivation | Effortfulness | [
"Biology"
] | 175 | [
"Ethology",
"Behavior",
"Motivation",
"Human behavior"
] |
13,619,909 | https://en.wikipedia.org/wiki/Waring%27s%20prime%20number%20conjecture | In number theory, Waring's prime number conjecture is a conjecture related to Vinogradov's theorem, named after the English mathematician Edward Waring. It states that every odd number exceeding 3 is either a prime number or the sum of three prime numbers. It follows from the generalized Riemann hypothesis, and (trivially) from Goldbach's weak conjecture.
See also
Schnirelmann's constant
References
External links
Additive number theory
Conjectures about prime numbers
Conjectures that have been proved | Waring's prime number conjecture | [
"Mathematics"
] | 105 | [
"Number theory stubs",
"Conjectures that have been proved",
"Mathematical problems",
"Mathematical theorems",
"Number theory"
] |
13,620,098 | https://en.wikipedia.org/wiki/Human%20Genome%20Sequencing%20Center | The Baylor College of Medicine Human Genome Sequencing Center (BCM-HGSC) was established by Richard A. Gibbs in 1996 when Baylor College of Medicine was chosen as one of six worldwide sites to complete the final phase of the international Human Genome Project. Gibbs is the current director of the BCM-HGSC.
It occupies more than , employing over 180 staff, and is one of three National Institutes of Health funded genome centers that were involved in the completion of the first human genome sequence. The BCM-HGSC contributed approximately 10 percent of the total project by sequencing chromosomes 3, 12 and X. The BCM-HGSC collaborated with researchers at the U.S. Department of Energy's Lawrence Berkeley National Laboratory and Celera Genomics to sequence the first species of fruit fly, Drosophila melanogaster. The BCM-HGSC also completed the second species of fruit fly (Drosophila pseudoobscura), the honeybee (Apis mellifera), and led an international consortium to sequence the brown Norway rat.
The BCM-HGSC subsequently sequenced and annotated the genome of the cow (Bos taurus), the sea urchin, rhesus macaque, tammar wallaby, Dictyostelium discoideum, and a number of bacteria that cause serious infections (Rickettsia typhi, Enterococcus faecium, Mannheimia haemolytica, and Fusobacterium nucleatum). The BCM-HGSC was a major contributor to the Mammalian Gene Collection program, to sequence all human cDNAs, as well as the International Haplotype Mapping Project (HapMap).
Other research within the BCM-HGSC includes new molecular technologies for mapping and sequencing, novel chemistries for DNA tagging, instrumentation for DNA manipulation, new computer programs for genomic data analysis, the genes expressed in childhood leukemias, the genomic differences that lead to evolutionary changes, the role of host genetic variation in the course of infectious disease, and the molecular basis of specific genetic diseases. The sequencing for the Drosophila Genetic Reference Panel (DGRP) was performed here. The DGRP is a collaborative effort started by Trudy Mackay to establish a common standard for Drosophila melanogaster research. The HGSC has an active bioinformatics program, with research projects involving biologists and computer scientists. Problems under study focus on developing tools for generating, manipulating, and analyzing genome data.
The BCM-HGSC is also involved with the Human Heredity and Health in Africa (H3Africa) Consortium. This collaboration resulted in a major study led by Neil Hanchard in which whole genome sequencing was performed on 426 individuals from 50 ethnolinguistic groups across Africa. As part of this study, more than 3 million previously un-described variants were uncovered.
References
Human genome projects | Human Genome Sequencing Center | [
"Biology"
] | 610 | [
"Human genome projects",
"Genome projects"
] |
13,620,523 | https://en.wikipedia.org/wiki/Cauchy%E2%80%93Hadamard%20theorem | In mathematics, the Cauchy–Hadamard theorem is a result in complex analysis named after the French mathematicians Augustin Louis Cauchy and Jacques Hadamard, describing the radius of convergence of a power series. It was published in 1821 by Cauchy, but remained relatively unknown until Hadamard rediscovered it. Hadamard's first publication of this result was in 1888; he also included it as part of his 1892 Ph.D. thesis.
Theorem for one complex variable
Consider the formal power series in one complex variable z of the form
where
Then the radius of convergence of f at the point a is given by
where denotes the limit superior, the limit as approaches infinity of the supremum of the sequence values after the nth position. If the sequence values is unbounded so that the is ∞, then the power series does not converge near , while if the is 0 then the radius of convergence is ∞, meaning that the series converges on the entire plane.
Proof
Without loss of generality assume that . We will show first that the power series converges for , and then that it diverges for .
First suppose . Let not be or
For any , there exists only a finite number of such that .
Now for all but a finite number of , so the series converges if . This proves the first part.
Conversely, for , for infinitely many , so if , we see that the series cannot converge because its nth term does not tend to 0.
Theorem for several complex variables
Let be an n-dimensional vector of natural numbers () with , then converges with radius of convergence , if and only if
of the multidimensional power series
Proof
From
Set Then
This is a power series in one variable which converges for and diverges for . Therefore, by the Cauchy–Hadamard theorem for one variable
Setting gives us an estimate
Because as
Therefore
Notes
External links
Augustin-Louis Cauchy
Mathematical series
Theorems in complex analysis | Cauchy–Hadamard theorem | [
"Mathematics"
] | 403 | [
"Sequences and series",
"Theorems in mathematical analysis",
"Mathematical structures",
"Series (mathematics)",
"Calculus",
"Theorems in complex analysis"
] |
13,620,970 | https://en.wikipedia.org/wiki/Miltos%20Manetas | Miltos Manetas (; born October 6, 1964, in Athens) is a Greek painter and multimedia artist. He currently lives and works in Bogotá.
Manetas has created internet art as well as paintings of cables, computers, video games and Internet websites since the late 1990s, notably since his participation in the 1995 Traffic (art exhibition) curated by Nicolas Bourriaud, which is often related to the beginning of the Relational art movement. Together with Mai Ueda, Manetas the co-founded "Neen", an art movement which aimed to conflate the new technology of the time with art and poetry. Neen was launched at Gagosian Gallery, New York City, in 2000.
Manetas presented the Whitneybiennial.com, an online exhibition that challenged the 2002 Whitney Biennial show.
His work has been collected by Charles Saatchi.
Career
Born in Athens, Greece to a prominent family from Arcadia, Miltos Manetas from the atelier of Vrasidas Vlachopoulos in Athens, moved to Milan at the age of 20, where he attended the Brera Academy. In 1995 he was included in Traffic, the survey exhibition curated by Nicolas Bourriaud that helped to launch the Relational Aesthetics art movement.
Manetas was categorized as one of idiots of that movement in the catalogue of the Traffic show,<ref>Bourriaud, Nicolas Traffic, Catalogue Capc Bordeaux, 1996</ref> and later, in Bourriaud's book Relational Aesthetics. But at this time, Manetas decided to change his approach to art, abandoning performance, objects and site specific installations, and he began making paintings about computer technology, exploring the possibilities of creating art by using video games and the Internet.
In 1996, Manetas moved to New York City and began working on a series of video game-related artworks, using Lara Croft and Mario as "ready-made" characters. In SuperMario Sleeping, a video from 1998, Mario sleeps under a tree, while in Flames, a 1997 video, Lara Croft is constantly getting hurt. Both works were exhibited at the Institute of Contemporary Arts, in the exhibition entitled Made in Italy. It was at that occasion that The Guardian published an article on Manetas calling him the El Greco of the geeks.
In subsequent years, Manetas displayed exhibitions throughout the world. Another important show was Elysian Fields at Centre Georges Pompidou in Paris, curated by the Purple Institute.
Manetas then commissioned a California branding agency to come up with a new term that would bring a radical change to his work. In spring of 2000, Manetas presented the new name, Neen, to an exhibition-performance held at the Gagosian Gallery in New York City.
Following this presentation, Manetas moved to Los Angeles, where he started his ElectronicOrphanage enterprise. He hired young people with experience in contemporary art and/or design, asking them to abandon what they were doing to test ideas for the Internet. In 2002, Manetas presented the Whitneybiennial.com, an online exhibition which challenged the 2002 Whitney Biennial show.
In 2007, London's Hayward Gallery commissioned Manetas to do a special project around the idea of Existential Computing, a new term he was using for his practice. During this show, Manetas met Malcolm McLaren and they participated together in a show that artist Stefan Bruggemann curated at the I-20 gallery in New York City in September 2007. Manetas' work for this exhibition was a piece commissioned previously by Newcastle's Baltic Centre for Contemporary Art and the British magazine Dazed & Confused for the Dazed & Confused versus Andy Warhol exhibition. It consisted solely of a URL written on the wall: http://www.ThankYouAndyWarhol.com.
In 2009, Manetas together with curator Jan Aman, created the first ever "Internet Pavilion" for the Venice Biennale. As a part of this work, they invited ThePirateBay and the Piratbyrån activists to participate and make their first "Embassy of Piracy."
Bibliography100 Years after Les Demoiselles d'Avignon, Essays by Miltos Manetas (London 2006, soft cover, 97 pages published by ElectronicOrphanage press)NEEN (by Miltos Manetas et al.; Italy, Charta, 2006, )
Notes
ReferencesMILTOS MANETAS, Paintings from Contemporary Life. (by Lev Manovich and Franck Gautherot, Published by Johan & Levi Editore, February 2009)
External links
Art website created by Manetas
Neen website
Mark Glaser's article in the NYT, Aug. 9, 2001
Matthew Mirapaul's article in the NYT, Mar. 4, 2002
Elizabeth Hayt's article in the NYT, Jun. 18, 2000.
The man from Neen - Salon.com, Mar. 21, 2002
Web watch, Sean Dodson, The Guardian'', 21 March 2002
1964 births
Living people
Multimedia artists
Artists from Athens
Greek painters
Greek contemporary artists
Brera Academy alumni | Miltos Manetas | [
"Technology"
] | 1,032 | [
"Multimedia",
"Multimedia artists"
] |
13,621,696 | https://en.wikipedia.org/wiki/Pathatrix | Pathatrix is a high volume recirculating immuno magnetic-capture system developed by Thermo Fisher Scientific (and supplier parts by Life Technologies) for the detection of pathogens in food and environmental samples.
History
Pathatrix and its Pathatrix Recirculating Immunomagnetic Separation System (RIMS) was used in 2006 to detect the E. coli O157:H7 strain in contaminated spinach using a polymerase chain reaction (PCR). The Pathatrix system is used by regulatory agencies and food companies around the world as a reliable method for detecting pathogens in food.
Unlike other detection methods, Pathatrix allows the entire pre-enriched sample or large pooled samples to be recirculated over antibody-coated paramagnetic beads. It can specifically isolate pathogens directly from food samples and in conjunction with quantitative PCR can provide results within hours. It is also used to improve the performance of other rapid methods such as PCR, lateral flow, ELISA and chromogenic media by reducing or eliminating the need for lengthy pre-enrichment and/or selective enrichment steps. The Pathatrix is useful in pathogen labs that would be running food samples and looking for foodborne diseases.
The Pathatrix is a rapid test method and Pathatrix pooling allows the screening of large numbers of food samples in a highly cost-effective way for specific pathogens such as E. coli O157, Salmonella or Listeria monocytogenes.
The Pathatrix will selectively bind and purify the target organism from a comprehensive range of complex food matrices (including raw ground beef, chocolate, peanut butter, leafy greens, spinach, tomatoes). The Pathatrix is a microbial detection system that allows for the entire sample to be analyzed.
References
Further reading
A.Y Asahina, R. Fujioka, A. Henry, P.C. Loh (2007) Using Indigenous Mollusks and Pathatrix to Detect Pathogens in Water. Dept. of Microbiology, University of Hawaii-Manoa, USA (34th Annual International Global Health Conference, Washington, D.C., USA, May 29 - June 1, 2007)
D.E. Hanes, L. Ewing-Peeples, M.H. Kothary, B.D. Tall (2008) Isolation of Francisella tularensis from Foods Using the Pathatrix Immunomagnetic Capture System. Food and Drug Administration (FDA), Laurel, MD, USA (6th ASM Biodefense & Emerging Diseases Research Meeting, Baltimore, MD, USA, February 24 – 27, 2008)
E. Papafragkou, M. Plante, K. Mattison, S. Bidawid, K. Karthikeyan, J.M. Farber, L.A. Jaykus (2008) Rapid and Sensitive Detection of Hepatitis A Virus (HAV) in Representative Food Matrices. Dept. of Food Science, North Carolina State University, Raleigh, NC, USA & Health Canada, Food Directorate, Bureau of Microbial Hazards, Ottawa, Ont., Canada (Journal of Virological Methods, 2008, 147, p177-187
S. Himathongkham, M.L. Dodd, J.K Yee, D.K. Lau, R.G. Bryant, A.S. Badoiu, H.K. Lau, L.S. Guthertz, L. Crawford-Miksza, M.A. Soliman, (2007) Recirculating Immunomagnetic Separation and Optimal Enrichment Conditions for Enhanced Detection and Recovery of Low Levels of Escherichia coli O157:H7 from Fresh Leafy Produce and Surface Water. Food and Drug Laboratory Branch, California Dept. of Public Health, Richmond, CA & U.S. Food and Drug Administration, San Francisco District Laboratory, Alameda, CA, USA (Journal of Food Protection, 2007, 70, No 12, p2717-2724))
Wu, Vivian (February 2004), "Rapid Protocol(5.25H) For The Detection Of Escherichia coli In Raw Ground Beef By An Immuno-Capture System (Pathatrix) In Combination With Colortrix and CT-SMAC", Journal of Rapid Methods and Automation in Microbiology, 2, (2004)57-67
Biological hazards
Biological techniques and tools | Pathatrix | [
"Biology"
] | 915 | [
"nan"
] |
13,621,774 | https://en.wikipedia.org/wiki/Canon%20of%20Eclipses | The Canon of Eclipses (German Canon der Finsternisse), published in 1887 at the Imperial Academy of Sciences of Vienna by Theodor Ritter von Oppolzer, is a compilation of over 13000 (8000 solar and 5200 lunar) eclipses, including all solar and all umbral lunar eclipses between the years 1208 BC and 2161 CE. It was republished by Dover Books in 1962.
References
External links
1887 Original German edition at Internet Archive
1887 non-fiction books
Astronomy books
German non-fiction books | Canon of Eclipses | [
"Astronomy"
] | 107 | [
"Astronomy books",
"Astronomy book stubs",
"Astronomy stubs",
"Works about astronomy"
] |
13,621,829 | https://en.wikipedia.org/wiki/Ateliers%20de%20Constructions%20Electriques%20de%20Charleroi | SA Ateliers de Constructions Electriques de Charleroi (ACEC) was a Belgian manufacturer of electrical generation, transmission, transport, lighting and industrial equipment, with origins dating to the late 19th century as a successor to the Société Électricité et Hydraulique founded by .
After World War II the company expanded into electronics, and became a contractor to the nuclear industry. The company was acquired by Westinghouse in 1970; in 1985 Westinghouse's share was acquired by Société Générale de Belgique (SGB) and Compagnie Générale d'Electricité (CGE).
The company operated at a loss during the 1980s, and was split and sold; Alstom and its affiliates acquired the majority of the company, along with ABB and Alcatel Bell and others. The remnants of the company were merged into Union Minière in 1989, forming ACEC Union Minière.
History
Background, 1878–1904
In 1878 Julien Dulait (1855–1926), son of steelworks engineer Jules Dulait began experiments into electrical and hydraulic machines; with co-worker Désiré Barras he created an electricity generating machine powered by an hydroelectric turbine. In 1881 the Compagnie générale d'Electricité was formed in Charleroi with Dulait as consulting engineer, constructing machines to Dulait's designs and those of Zénobe Gramme.
In 1886 the company was renamed becoming Société anonyme Électricité et Hydraulique à Charleroi (E&H), by this time the factory was producing dynamos with over 100 kW power. By 1900 the company had supplied electric lighting to the cities of Liege, Charleroi and Schaerbeek, and opened a new factory in Marcinelle/Marchienne. In 1904 the company supplied trams for a line in Cointe, Liege- – the first entirely Belgian built trams.
The company's product range included dynamos, lifts, carbon arc lamps, electric traction motors for trams and drilling equipment.
In 1898, the company established a factory in France in Jeumont (France/Belgium border).
On 7 July 1904, the company became Ateliers de Constructions électriques de Charleroi (ACEC), having been acquired by Baron Edouard Empain; Empain made an entry into the electrical industry in an attempt to counter German companies' share of the Belgian market.
The Jeumont, France factory was renamed Ateliers de constructions électriques du Nord et de l'Est (ACENE) in 1906; much later (1960s) becoming part of Jeumont Schneider.
ACEC, 1904–1970
After its foundation in 1904 the company expanded in the next decade, establishing several new factories including ones for electrical cables, machine and tool making, and large machines. In 1914 the company began manufacturing motor vehicles, with an electric transmission system, to the design of Balachowsky & Caire. During World War I the factory was stripped of machines by occupying German forces.
Between the wars, ACEC began to produce vacuum-based electronics, including mercury arc rectifiers, which replaced rotary converters on Brussels trams in 1929. The company also produced a high-power test installations, capable of producing 2.5GW in short circuit, with currents and voltages of up to 267kA and 250kV.
In 1939 ACEC began to collaborate with Constructions Electriques de Belgique (CEB), with the two companies rationalising their combined production.
During the build-up to World War II the factory was commissioned to manufacture 75mm anti-aircraft guns, 47mm anti-tank guns and other weapons, as well as variable-pitch propellers and parts for Hispano-Suiza aircraft. After the outbreak of war preparations were made to relocate the factories, and some production was restarted at a Hispano-Suiza factory near Tarbes, France. The Charleroi plant was initially taken under the control of the German armed forces. By 1942 raw materials, manufactured parts and tools were beginning to become scarce, and workers at the plant began to be commandeered to work in factories in Germany, mainly those of AEG, Siemens and Brown-Boveri.
In 1947 the collaboration with CEB concluded with the two companies merging, forming ACEC Herstal.
ACEC also acted as a contractor and equipment supplier to the nuclear industry, supplying sensor and handling systems including fuel rod handling, pumps for coolant systems and instrumentation, as well as conventional power plant equipment such as main generators, pumps, control systems, instrumentation and computer systems. In 1957, the company entered into a licensing arrangement with Westinghouse relating to PWR reactors.
In the three decades after World War II the company also expanded into the electronics industry, starting to manufacture products including tape recorders, televisions, and radios.
The Société Electro Meccanique (SEM) (Ghent) was absorbed in 1960/1.
In 1970, it became a member of the Westinghouse group. Over the next two decades the company was restructured and its various operations sold off, much of the company being acquired by Compagnie Générale d'Electricité (CGE).
ACEC breakup, 1970–1989
The ACEC cable factory was split as a separate company câblerie de Charleroi in 1971, and acquired by Compagnie Générale d'Electricité (CGE) in 1986, as of 2012 a factory in Charleroi is part of Nexans Benelux (Nexans group) and manufacturers medium and high voltage electric (up to 500kV) cable.
Westinghouse reduced its shareholding to less than 50% by the late 1970s,
In 1985, Inductotherm Industries acquired four induction heating businesses from ACEC, including Elphiac (Herstal, Belgium, joint company with Philips).
The Société Générale de Belgique (SGB) and Compagnie Générale d'Electricité (CGE) agreed to acquire Westinghouse's (42%) share in the company in 1985, becoming joint majority shareholders.
The company restructured in the 1980s, reducing its workforce from over 5000 in 1985 to 2200 in 1998. The company reported losses of over 4 billion Belgian francs (BF) in 1986, and over 500million loss in 1987. In 1988 the company was still in very poor financial condition; in the first half of 1988 it lost 570million BF on revenues of nearly 4billion Belgian francs. The main shareholders of ACEC's owner SGB (Suez group and Carlo De Benedetti) announced that the company was to be sold.
Many of the company's divisions were acquired by CGE subsidiaries (Alstom, Alcatel). Rail vehicle traction equipment manufacturer Kiepe Elektrik (acquired 1973) was sold to Alstom in 1988. The automation and energy divisions became majority owned by CGEE Alsthom (CGE subsidiary) as ACEC Automatisme SA, and ACEC Energie SA. The rail transport equipment subsidiary became a 100% owned subsidiary of Alsthom as ACEC Transport SA. in 1989; a plant in Herstal was closed, and traction motor manufacture ceased at Charleroi, moving to one of Alstom's French sites.
ABB acquired ACEC's mechanical engineering facilities in Ghent in 1988, effective April 1989, forming ACEC Turbo Power Systems SA (ATPS). The steel construction business "ACEC construction soudée" was sold to Cassart (Fernelmont, Belgium).
ACEC-SDT (space, defence, telecommunications) was merged into Alcatel-Bell (CGE majority owner, via Alcatel NV) forming Acatel-Bell-SDT.
By June 1989, the SGB was the only remaining shareholder of ACEC, trading of shares was suspended on 5 July 1989, in July 1989 the remnants of the company, considered essentially valueless, with estimated liabilities of over 7billion BF were merged into the company Union Minière, forming Acec-Union Minière. The merger, where ACEC absorbed UM, allowed to compensate the tax on UM's profits by carrying forward ACEC's losses.
ACEC Union Minière, 1989–1992
The information technology company ACEC-OSI was absorbed into Tractebel subsidiary Trasys (Belgium) in 1989.
The pump machinery division was (ACEC centrifugal pumps) acquired (from ACEC Union Minière) by BW/IP in 1992. BW/IP successor Flowserve closed the Charleroi pump factory in 1997.
After the sale of the centrifugal pumps division, no significant parts of ACEC remained in the Union Minière; it was renamed Umicore in 1992.
See also
Manx Electric Railway rolling stock, retains original power cars from the late 1890s with E&H traction motors.
Tihange Nuclear Power Station and Doel Nuclear Power Station, Belgian nuclear powerplants; all (Doel 1–4, and Tihange 1–3) had equipment supplied by ACEC in consortia with other companies.
, and ; built with ACEC equipment – in particular electric manoeuvring propellers.
ACEC Cobra, ACEC developed armoured vehicle (1977) with electric transmission.
References
Further reading
External links
ACEC
Engineering companies of Belgium
Electrical engineering companies
Companies based in Hainaut (province) | Ateliers de Constructions Electriques de Charleroi | [
"Engineering"
] | 1,941 | [
"Electrical engineering organizations",
"Electrical engineering companies",
"Engineering companies"
] |
13,622,588 | https://en.wikipedia.org/wiki/SOD1 | Superoxide dismutase [Cu-Zn] also known as superoxide dismutase 1 or hSod1 is an enzyme that in humans is encoded by the SOD1 gene, located on chromosome 21. SOD1 is one of three human superoxide dismutases. It is implicated in apoptosis, familial amyotrophic lateral sclerosis and Parkinson's disease.
Structure
SOD1 is a 32 kDa homodimer which forms a beta barrel (β-barrel) and contains an intramolecular disulfide bond and a binuclear Cu/Zn site in each subunit. This Cu/Zn site holds the copper and a zinc ion and is responsible for catalyzing the disproportionation of superoxide to hydrogen peroxide and dioxygen. The maturation process of this protein is complex and not fully understood, involving the selective binding of copper and zinc ions, formation of the intra-subunit disulfide bond between Cys-57 and Cys-146, and dimerization of the two subunits. The copper chaperone for Sod1 (CCS) facilitates copper insertion and disulfide oxidation. Although SOD1 is synthesized in the cytosol and can mature there, the fraction of expressed but still immature SOD1 that is targeted to the mitochondria must be inserted into the intermembrane space. There, it forms the disulfide bond, though not metalation, required for its maturation. The mature protein is highly stable, but unstable when in its metal-free and disulfide-reduced forms. This manifests in vitro, as the loss of metal ions results in increased SOD1 aggregation, and in disease models, where low metalation is observed for insoluble SOD1. Moreover, the surface-exposed reduced cysteines could participate in disulfide crosslinking and, thus, aggregation.
Function
SOD1 binds copper and zinc ions and is one of three superoxide dismutases responsible for destroying free superoxide radicals in the body. The encoded isozyme is a soluble cytoplasmic and mitochondrial intermembrane space protein, acting as a homodimer to convert naturally occurring, but harmful, superoxide radicals to molecular oxygen and hydrogen peroxide. Hydrogen peroxide can then be broken down by another enzyme called catalase.
SOD1 has been postulated to localize to the outer mitochondrial membrane (OMM), where superoxide anions would be generated, or the intermembrane space. The exact mechanisms for its localization remains unknown, but its aggregation to the OMM has been attributed to its association with BCL-2. Wildtype SOD1 has demonstrated antiapoptotic properties in neural cultures, while mutant SOD1 has been observed to promote apoptosis in spinal cord mitochondria, but not in liver mitochondria, though it is equally expressed in both. Two models suggest SOD1 inhibits apoptosis by interacting with BCL-2 proteins or the mitochondria itself.
Clinical significance
Role in oxidative stress
Most notably, SOD1 is pivotal in reactive oxygen species (ROS) release during oxidative stress by ischemia-reperfusion injury, specifically in the myocardium as part of a heart attack (also known as ischemic heart disease). Ischemic heart disease, which results from an occlusion of one of the major coronary arteries, is currently still the leading cause of morbidity and mortality in western society. During ischemia reperfusion, ROS release substantially contribute to the cell damage and death via a direct effect on the cell as well as via apoptotic signals. SOD1 is known to have a capacity to limit the detrimental effects of ROS. As such, SOD1 is important for its cardioprotective effects. In addition, SOD1 has been implicated in cardioprotection against ischemia-reperfusion injury, such as during ischemic preconditioning of the heart. Although a large burst of ROS is known to lead to cell damage, a moderate release of ROS from the mitochondria, which occurs during nonlethal short episodes of ischemia, can play a significant triggering role in the signal transduction pathways of ischemic preconditioning leading to reduction of cell damage. It even has been observed that during this release of ROS, SOD1 plays an important role hereby regulating apoptotic signaling and cell death.
In one study, deletions in the gene were reported in two familial cases of keratoconus. Mice lacking SOD1 have increased age-related muscle mass loss (sarcopenia), early development of cataracts, macular degeneration, thymic involution, hepatocellular carcinoma, and shortened lifespan. Research suggests that increased SOD1 levels could be a biomarker for chronic heavy metal toxicity in women with long-term dental amalgam fillings.
Amyotrophic lateral sclerosis (Lou Gehrig's disease)
Mutations (over 150 identified to date) in this gene have been linked to familial amyotrophic lateral sclerosis. However, several pieces of evidence also show that wild-type SOD1, under conditions of cellular stress, is implicated in a significant fraction of sporadic ALS cases, which represent 90% of ALS patients.
The most frequent mutations are A4V (in the U.S.A.) and H46R (Japan). In Iceland only SOD1-G93S has been found. The most studied ALS mouse model is G93A. Rare transcript variants have been reported for this gene.
Virtually all known ALS-causing SOD1 mutations act in a dominant fashion; a single mutant copy of the SOD1 gene is sufficient to cause the disease. The exact molecular mechanism (or mechanisms) by which SOD1 mutations cause disease are unknown. It appears to be some sort of toxic gain of function, as many disease-associated SOD1 mutants (including G93A and A4V) retain enzymatic activity and Sod1 knockout mice do not develop ALS (although they do exhibit a strong age-dependent distal motor neuropathy).
ALS is a neurodegenerative disease characterized by selective loss of motor neurons causing muscle atrophy. The DNA oxidation product 8-OHdG is a well-established marker of oxidative DNA damage. 8-OHdG accumulates in the mitochondria of spinal motor neurons of persons with ALS. In transgenic ALS mice harboring a mutant SOD1 gene, 8-OHdG also accumulates in mitochondrial DNA of spinal motor neurons. These findings suggest that oxidative damage to mitochondrial DNA of motor neurons due to altered SOD1 may be significant factor in the etiology of ALS.
A4V mutation
A4V (alanine at codon 4 changed to valine) is the most common ALS-causing mutation in the U.S. population, with approximately 50% of SOD1-ALS patients carrying the A4V mutation. Approximately 10 percent of all U.S. familial ALS cases are caused by heterozygous A4V mutations in SOD1. The mutation is rarely if ever found outside the Americas.
It was recently estimated that the A4V mutation occurred 540 generations (~12,000 years) ago. The haplotype surrounding the mutation suggests that the A4V mutation arose in the Asian ancestors of Native Americans, who reached the Americas through the Bering Strait.
The A4V mutant belongs to the WT-like mutants. Patients with A4V mutations exhibit variable age of onset, but uniformly very rapid disease course, with average survival after onset of 1.4 years (versus 3–5 years with other dominant SOD1 mutations, and in some cases such as H46R, considerably longer). This survival is considerably shorter than non-mutant SOD1 linked ALS.
H46R mutation
H46R (histidine at codon 46 changed to arginine) is the most common ALS-causing mutation in the Japanese population, with about 40% of Japanese SOD1-ALS patients carrying this mutation. H46R causes a profound loss of copper binding in the active site of SOD1, and as such, H46R is enzymatically inactive. The disease course of this mutation is extremely long, with the typical time from onset to death being over 15 years. Mouse models with this mutation do not exhibit the classical mitochondrial vacuolation pathology seen in G93A and G37R ALS mice and unlike G93A mice, deficiency of the major mitochondrial antioxidant enzyme, SOD2, has no effect on their disease course.
G93A mutation
G93A (glycine 93 changed to alanine) is a comparatively rare mutation, but has been studied very intensely as it was the first mutation to be modeled in mice. G93A is a pseudo-WT mutation that leaves the enzyme activity intact. Because of the ready availability of the G93A mouse from Jackson Laboratory, many studies of potential drug targets and toxicity mechanisms have been carried out in this model. At least one private research institute (ALS Therapy Development Institute) is conducting large-scale drug screens exclusively in this mouse model. Whether findings are specific for G93A or applicable to all ALS-causing SOD1 mutations is at present unknown. It has been argued that certain pathological features of the G93A mouse are due to overexpression artifacts, specifically those relating to mitochondrial vacuolation (the G93A mouse commonly used from Jackson Lab has over 20 copies of the human SOD1 gene). At least one study has found that certain features of pathology are idiosyncratic to G93A and not extrapolatable to all ALS-causing mutations. Further studies have shown that the pathogenesis of the G93A and H46R models are clearly distinct; some drugs and genetic interventions that are highly beneficial/detrimental in one model have either the opposite or no effect in the other.
Down syndrome
Down syndrome (DS) is usually caused by a triplication of chromosome 21. Oxidative stress is thought to be an important underlying factor in DS-related pathologies. The oxidative stress appears to be due to the triplication and increased expression of the SOD1 gene located in chromosome 21. Increased expression of SOD1 likely causes increased production of hydrogen peroxide leading to increased cellular injury.
The levels of 8-OHdG in the DNA of persons with DS, measured in saliva, were found to be significantly higher than in control groups. 8-OHdG levels were also increased in the leukocytes of persons with DS compared to controls. These findings suggest that oxidative DNA damage may lead to some of the clinical features of DS.
Interactions
SOD1 has been shown to interact with CCS and Bcl-2.
References
Further reading
112-115. sod 1
Genes on human chromosome 21
Copper enzymes
Zinc enzymes
Metalloproteins
Oxidoreductases | SOD1 | [
"Chemistry"
] | 2,354 | [
"Metalloproteins",
"Oxidoreductases",
"Bioinorganic chemistry"
] |
13,622,958 | https://en.wikipedia.org/wiki/Bryant%20surface | In Riemannian geometry, a Bryant surface is a 2-dimensional surface embedded in 3-dimensional hyperbolic space with constant mean curvature equal to 1. These surfaces take their name from the geometer Robert Bryant, who proved that every simply-connected minimal surface in 3-dimensional Euclidean space is isometric to a Bryant surface by a holomorphic parameterization analogous to the (Euclidean) Weierstrass–Enneper parameterization.
References
Hyperbolic geometry
Riemannian geometry
Minimal surfaces | Bryant surface | [
"Chemistry"
] | 102 | [
"Foams",
"Minimal surfaces"
] |
13,623,185 | https://en.wikipedia.org/wiki/Injection%20locking | Injection locking and injection pulling are the frequency effects that can occur when a harmonic oscillator is disturbed by a second oscillator operating at a nearby frequency. When the coupling is strong enough and the frequencies near enough, the second oscillator can capture the first oscillator, causing it to have essentially identical frequency as the second oscillator. This is injection locking. When the second oscillator merely disturbs the first but does not capture it, the effect is called injection pulling. Injection locking and pulling effects are observed in numerous types of physical systems, however the terms are most often associated with electronic oscillators or laser resonators.
Injection locking has been used in beneficial and clever ways in the design of early television sets and oscilloscopes, allowing the equipment to be synchronized to external signals at a relatively low cost. Injection locking has also been used in high performance frequency doubling circuits. However, injection locking and pulling, when unintended, can degrade the performance of phase-locked loops and RF integrated circuits.
Injection from grandfather clocks to lasers
Injection pulling and injection locking can be observed in numerous physical systems where pairs of oscillators are coupled together. Perhaps the first to document these effects was Christiaan Huygens, the inventor of the pendulum clock, who was surprised to note that two pendulum clocks which normally would keep slightly different time nonetheless became perfectly synchronized when hung from a common beam. Modern researchers have confirmed his suspicion that the pendulums were coupled by tiny back-and-forth vibrations in the wooden beam. The two clocks became injection locked to a common frequency.
In a modern-day voltage-controlled oscillator an injection-locking signal may override its low-frequency control voltage, resulting in loss of control. When intentionally employed, injection locking provides a means to significantly reduce power consumption and possibly reduce phase noise in comparison to other frequency synthesizer and PLL design techniques. In similar fashion, the frequency output of large lasers can be purified by injection locking them with high accuracy reference lasers (see injection seeder).
Injection-locked oscillator
An injection-locked oscillator (ILO) is usually based on cross-coupled LC oscillator. It has been employed for frequency division or jitter reduction in PLL, with the input of pure sinusoidal waveform. It was employed in continuous mode clock and data recovery (CDR) or clock recovery to perform clock restoration from the aid of either preceding pulse generation circuit to convert non-return-to-zero (NRZ) data to pseudo-return-to-zero (PRZ) format or nonideal retiming circuit residing at the transmitter side to couple the clock signal into the data. In the late 2000s, the ILO was employed for a burst-mode clock-recovery scheme.
The ability to injection-lock is an inherent property of all oscillators (electronic or otherwise). This capability can be fundamentally understood as the combined effect of the oscillator's periodicity with its autonomy. Specifically, consider a periodic injection (i.e., external disturbance) that advances or lags the oscillator's phase by some phase shift every oscillation cycle. Due to the oscillator's periodicity, this phase shift will be the same from cycle to cycle if the oscillator is injection-locked. Moreover, due to the oscillator's autonomy, each phase shift persists indefinitely. Combining these two effects produces a fixed phase shift per oscillation cycle, which results in a constant frequency shift over time. If the resultant, shifted oscillation frequency matches the injection frequency, the oscillator is said to be injection-locked. However, if the maximum frequency shift that the oscillator can experience due to the injection is not enough to cause the oscillation and injection frequencies to coincide (i.e., the injection frequency lies outside the lock range), the oscillator can only be injection pulled (see ).
Unwanted injection locking
High-speed logic signals and their harmonics are potential threats to an oscillator. The leakage of these and other high frequency signals into an oscillator through a substrate concomitant with an unintended lock is unwanted injection locking.
Gain by injection locking
Injection locking can also provide a means of gain at a low power cost in certain applications.
Injection pulling
Injection (aka frequency) pulling occurs when an interfering frequency source disturbs an oscillator but is unable to injection lock it. The frequency of the oscillator is pulled towards the frequency source as can be seen in the spectrogram. The failure to lock may be due to insufficient coupling, or because the injection source frequency lies outside the locking window (also known as the lock range) of the oscillator. Injection pulling fundamentally corrupts the inherent periodicity of an oscillator.
Entrainment
Entrainment has been used to refer to the process of mode locking of coupled driven oscillators, which is the process whereby two interacting oscillating systems, which have different periods when they function independently, assume a common period. The two oscillators may fall into synchrony, but other phase relationships are also possible. The system with the greater frequency slows down, and the other speeds up.
Dutch physicist Christiaan Huygens, the inventor of the pendulum clock, introduced the concept after he noticed, in 1666, that the pendulums of two clocks mounted on a common board had synchronized, and subsequent experiments duplicated this phenomenon. He described this effect as "odd sympathy". The two pendulum clocks synchronized with their pendulums swinging in opposite directions, 180° out of phase, but in-phase states can also result. Entrainment occurs because small amounts of energy are transferred between the two systems when they are out of phase in such a way as to produce negative feedback. As they assume a more stable phase relationship, the amount of energy gradually reduces to zero. In the realm of physics, Huygens' observations are related to resonance and the resonant coupling of harmonic oscillators, which also gives rise to sympathetic vibrations.
A 2002 study of Huygens' observations show that an antiphase stable oscillation was somewhat fortuitous, and that there are other possible stable solutions, including a "death state" where a clock stops running, depending on the strength of the coupling between the clocks.
Mode locking between driven oscillators can be easily demonstrated using mechanical metronomes on a common, easily movable surface. Such mode locking is important for many biological systems including the proper operation of pacemakers.
The use of the word entrainment in the modern physics literature most often refers to the movement of one fluid, or collection of particulates, by another. The use of the word to refer to mode locking of non-linear coupled oscillators appears mostly after about 1980, and remains relatively rare in comparison.
A similar coupling phenomenon was characterized in hearing aids when the adaptive feedback cancellation is used. This chaotic artifact (entrainment) is observed when correlated input signals are presented to an adaptive feedback canceller.
In recent years, aperiodic entrainment has been identified as an alternative form of entrainment that is of interest in biological rhythms.
See also
Injection-locked frequency divider
Phase-locked loop
LC oscillator
Electronic oscillator
Burst mode clock and data recovery
Entrainment (hydrodynamics)
Brainwave synchronization
Synchronization of chaos
Phase-locked loop range
Tidal locking
References
Filter Entrainment Avoidance with a Frequency Domain Transform Algorithm
Entrainment Avoidance with Pole Stabilization
Entrainment Avoidance with a Transform Domain Algorithm
Entrainment Avoidance with an Auto Regressive Filter
Further reading
* Wolaver, Dan H. 1991. Phase-Locked Loop Circuit Design, Prentice Hall, , pages 95–105
* Lee, Thomas H. 2004. The Design of CMOS Radio-Frequency Integrated Circuits, Cambridge, , pages 563–566
External links
Demonstration of injection locking.
Injection locking of 100 metronomes
Electronic oscillators
Dynamical systems | Injection locking | [
"Physics",
"Mathematics"
] | 1,688 | [
"Mechanics",
"Dynamical systems"
] |
13,623,703 | https://en.wikipedia.org/wiki/Sector%20slipping | Sector slipping is a technique used to deal with defective sectors in hard disk drives. Due to the volatility of hard disks from their moving parts and low tolerances, some sectors become defective. Defective sectors can even come on hard disks from the factory, so most disks incorporate a bad-block recovery system to help cope with these issues.
Description
During a low-level format, defect lists are populated, which store a list of bad sectors, which are then mapped and a sector slipping algorithm is utilized. When using sector slipping for bad sectors, disk access time is not largely affected. The drive will skip over a bad sector using the time it would have used to read it. Spare sectors are located on the disk to aid in having sectors to “slip” other sectors down to, allowing for the preservation of sequential ordering of the data. Accuracy of programs, reliant on static knowledge of cylinders and block positions will be compromised, however.
Bad sectors that are found during normal usage of the disk are not capable of having the sector slipping algorithm applied. Instead, a linear reallocation, or sector forwarding, is used where a bad sector is replaced with a sector from a spare area. Doing this affects the access times, as the disk will need to seek to the spare sector since all further lookups of the bad sector will redirect to the new sector.
Example
Logical Sectors Physical Sectors
Pre Low-Level Format
0 0
1 1
2 2
3 3
4 4
5 5
6
7
Logical Sectors Physical Sectors
Post Low-Level Format
0 -------> 0
1 -------> 1
2 -------> 2
3 (Bad)
3 -------> 4
5 (Bad)
4 -------> 6
5 -------> 7
In this example, physical sectors 3 and 5 were found to be bad. The sectors were then slipped down to allow for the logical sectors to be placed in sequential order on good sectors. Sector 3 was slipped down to 4 and sector 4 was slipped down to 6. The rest of the sectors were slipped down to the remaining spare sectors: Sector 4 to 6 and sector 5 to 7.
References
Silberschatz, Galvin and Gagne; Operating System Concepts, 7th Ed.
Worthington, Bruce, L.; Ganger, Gregory R. and Patt, Yale N.; Scheduling for Modern Disk Drives and Non-Random Workloads
Computer data
Computer file systems | Sector slipping | [
"Technology"
] | 515 | [
"Computer data",
"Data"
] |
13,624,133 | https://en.wikipedia.org/wiki/Microprocessor%20chronology |
1970s
The first chips that could be considered microprocessors were designed and manufactured in the late 1960s and early 1970s, including the MP944 used in the Grumman F-14 . Intel's 4004 of 1971 is widely regarded as the first commercial microprocessor.
Designers predominantly used MOSFET transistors with pMOS logic in the early 1970s, switching to nMOS logic after the mid-1970s. nMOS had the advantage that it could run on a single voltage, typically +5V, which simplified the power supply requirements and allowed it to be easily interfaced with the wide variety of +5V transistor-transistor logic (TTL) devices. nMOS had the disadvantage that it was more susceptible to electronic noise generated by slight impurities in the underlying silicon material, and it was not until the mid-1970s that these, sodium in particular, were successfully removed to the required levels. At that time, around 1975, nMOS quickly took over the market.
This corresponded with the introduction of new semiconductor masking systems, notably the Micralign system from Perkin-Elmer. Micralign projected an image of the mask onto the silicon wafer, never touching it directly, which eliminated the previous problems when the mask would be lifted off the surface and take away some of the photoresist along with it, ruining the chips on that portion of the wafer. By reducing the number of flawed chips, from about 70% to 10%, the cost of complex designs like early microprocessors fell by the same amount. Systems based on contact aligners cost on the order of $300 in single-unit quantities, the MOS 6502, designed specifically to take advantage of these improvements, cost only $25.
This period also saw considerable experimentation with various word lengths. Early on, 4-bit processors were common, like the Intel 4004, simply because making a wider word length could not be accomplished cost-effectively in the room available on the small wafers of the era, especially when the majority would be defective. As yields improved, wafer sizes grew, and feature size continued to be reduced, more complex 8-bit designs emerged like the Intel 8080 and 6502. 16-bit processors emerged early but were expensive; by the decade's end, low-cost 16-bit designs like the Zilog Z8000 were becoming common. Some unusual word lengths were also produced, including 12-bit and 20-bit, often matching a design that had previously been implemented in a multi-chip format in a minicomputer. These had largely disappeared by the end of the decade as minicomputers moved to 32-bit formats.
1980s
As Moore's Law continued to drive the industry towards more complex chip designs, the expected widespread move from 8-bit designs of the 1970s to 16-bit designs almost didn't occur; instead, new 32-bit designs like the Motorola 68000 and National Semiconductor NS32000 emerged that offered far more performance. The only widespread use of 16-bit systems was in the IBM PC, which had selected the Intel 8088 in 1979 before the new designs had matured.
Another change was the move to CMOS gates as the primary method of building complex CPUs. CMOS had been available since the early 1970s; RCA introduced the COSMAC processor using CMOS in 1975. Whereas earlier systems used a single transistor as the basis for each "gate", CMOS used a two-sided design, essentially making it twice as expensive to build. Its advantage was that its logic was not based on the voltage of a transistor compared to the silicon substrate, but the difference in voltages between the two sides, which was detectable at much lower power levels. As processor complexity continued to grow, power dissipation had become a significant concern and chips were prone to overheating; CMOS greatly reduced this problem and quickly took over the market. This was aided by the uptake of CMOS by Japanese firms while US firms remained on nMOS, giving the Japanese industry a major advance during the 1980s.
Semiconductor fabrication techniques continued to improve throughout. The Micralign, which had "created the modern IC industry", was obsolete by the early 1980s. They were replaced by the new steppers, which used high magnifications and extremely powerful light sources to allow a large mask to be copied onto the wafer at ever-smaller sizes. This technology allowed the industry to break below the former 1 micron limit.
Key home computers in the early part of the decade predominantly use processors developed in the 1970s. Versions of the 6502, first released in 1975, powered the Commodore 64, Apple II, BBC Micro, and Atari 8-bit computers. The 8-bit Zilog Z80 (1976) is at the core of the ZX Spectrum, MSX systems and many others. The 8086-based IBM PC, launched in 1981, started the move to 16-bit, but was soon passed by the 68000-based 16/32-bit Macintosh, then the Atari ST and Amiga. IBM PC compatibles moved to 32-bit with the introduction of the Intel 80386 in late 1985, although 386-based systems were considerably expensive at the time.
In addition to ever-growing word lengths, microprocessors began to add additional functional units that had previously been optional external parts. By the middle of the decade, memory management units (MMUs) were becoming commonplace, first appearing on designs like the Intel 80286 and Motorola 68030. By the end of the decade, floating point units (FPUs) were being added, first appearing on 1989s Intel 486 and followed the next year by the Motorola 68040.
Another change that began during the 1980s involved overall design philosophy with the emergence of the reduced instruction set computer, or RISC. Although the concept was first developed by IBM in the 1970s, the company did not introduce powerful systems based on it, largely for fear of cannibalizing their sales of larger mainframe systems. Market introduction was driven by smaller companies like MIPS Technologies, SPARC and ARM. These companies did not have access to high-end fabrication like Intel and Motorola, but were able to introduce chips that were highly competitive with those companies with a fraction of the complexity. By the end of the decade, every major vendor was introducing a RISC design of their own, like the IBM POWER, Intel i860 and Motorola 88000.
1990s
The 32-bit microprocessor dominated the consumer market in the 1990s. Processor clock speeds increased by more than tenfold between 1990 and 1999, and 64-bit processors began to emerge later in the decade. In the 1990s, microprocessors no longer used the same clock speed for the processor and the RAM. Processors began to have a front-side bus (FSB) clock speed used in communication with RAM and other components. Typically, the processor itself ran at a clock speed that was a multiple of the FSB clock speed. Intel's Pentium III, for example, had an internal clock speed of 450–600 MHz and an FSB speed of 100–133 MHz. Only the processor's internal clock speed is shown here.
2000s
64-bit processors became mainstream in the 2000s. Microprocessor clock speeds reached a ceiling because of the heat dissipation barrier. Instead of implementing expensive and impractical cooling systems, manufacturers turned to parallel computing in the form of the multi-core processor. Overclocking had its roots in the 1990s, but came into its own in the 2000s. Off-the-shelf cooling systems designed for overclocked processors became common, and the gaming PC had its advent as well. Over the decade, transistor counts increased by about an order of magnitude, a trend continued from previous decades. Process sizes decreased about fourfold, from 180 nm to 45 nm.
2010s
A new trend appears, the multi-chip module made of several chiplets. This is multiple monolithic chips in a single package. This allows higher integration with several smaller and easier to manufacture chips.
2020s
See also
Moore's law
Transistor count per chip, chronology
Timeline of instructions per second architectural chip performance chronology
Tick–tock model, and its successor:
Process–architecture–optimization model
References and notes
References
Notes
sandpile.org for x86 processor information
Digital electronics
Microprocessor
AAA
Computer performance | Microprocessor chronology | [
"Technology",
"Engineering"
] | 1,734 | [
"Electronic engineering",
"Computer performance",
"Digital electronics"
] |
13,624,160 | https://en.wikipedia.org/wiki/Churchill%E2%80%93Bernstein%20equation | In convective heat transfer, the Churchill–Bernstein equation is used to estimate the surface averaged Nusselt number for a cylinder in cross flow at various velocities. The need for the equation arises from the inability to solve the Navier–Stokes equations in the turbulent flow regime, even for a Newtonian fluid. When the concentration and temperature profiles are independent of one another, the mass-heat transfer analogy can be employed. In the mass-heat transfer analogy, heat transfer dimensionless quantities are replaced with analogous mass transfer dimensionless quantities.
This equation is named after Stuart W. Churchill and M. Bernstein, who introduced it in 1977. This equation is also called the Churchill–Bernstein correlation.
Heat transfer definition
where:
is the surface averaged Nusselt number with characteristic length of diameter;
is the Reynolds number with the cylinder diameter as its characteristic length;
is the Prandtl number.
The Churchill–Bernstein equation is valid for a wide range of Reynolds numbers and Prandtl numbers, as long as the product of the two is greater than or equal to 0.2, as defined above. The Churchill–Bernstein equation can be used for any object of cylindrical geometry in which boundary layers develop freely, without constraints imposed by other surfaces. Properties of the external free stream fluid are to be evaluated at the film temperature in order to account for the variation of the fluid properties at different temperatures. One should not expect much more than 20% accuracy from the above equation due to the wide range of flow conditions that the equation encompasses. The Churchill–Bernstein equation is a correlation and cannot be derived from principles of fluid dynamics. The equation yields the surface averaged Nusselt number, which is used to determine the average convective heat transfer coefficient. Newton's law of cooling (in the form of heat loss per surface area being equal to heat transfer coefficient multiplied by temperature gradient) can then be invoked to determine the heat loss or gain from the object, fluid and/or surface temperatures, and the area of the object, depending on what information is known.
Mass transfer definition
where:
is the Sherwood number related to hydraulic diameter
is the Schmidt number
Using the mass-heat transfer analogy, the Nusselt number is replaced by the Sherwood number, and the Prandtl number is replaced by the Schmidt number. The same restrictions described in the heat transfer definition are applied to the mass transfer definition. The Sherwood number can be used to find an overall mass transfer coefficient and applied to Fick's law of diffusion to find concentration profiles and mass transfer fluxes.
See also
Prandtl number
Reynolds number
Notes
References
Heat transfer
Convection | Churchill–Bernstein equation | [
"Physics",
"Chemistry"
] | 529 | [
"Transport phenomena",
"Physical phenomena",
"Heat transfer",
"Convection",
"Thermodynamics"
] |
13,624,220 | https://en.wikipedia.org/wiki/Burst%20mode%20clock%20and%20data%20recovery | The passive optical network (PON) uses tree-like network topology. Due to the topology of PON, the transmission modes for downstream (that is, from optical line termination, (OLT) to optical network unit (ONU)) and upstream (that is, from ONU to OLT) are different. For the downstream transmission, the OLT broadcasts optical signal to all the ONUs in continuous mode (CM), that is, the downstream channel always has optical data signal. One given ONU can find which frame in the CM stream is for it by reading the header of the frame. However, in the upstream channel, ONUs can not transmit optical data signal in CM. It is because that all the signals transmitted from the ONUs converge (with attenuation) into one fiber by the power splitter (serving as power coupler), and overlap among themselves if CM is used. To solve this problem, burst mode (BM) transmission is adopted for upstream channel. The given ONU only transmits optical packet when it is allocated a time slot and it needs to transmit, and all the ONUs share the upstream channel in the time division multiple access (TDMA) mode. The phases of the BM optical packets received by the OLT are different from packet to packet, since the ONUs are not synchronized to transmit optical packet in the same phase, and the distance between OLT and given ONU are random. In order to compensate the phase variation from packet to packet, burst mode clock and data recovery (BM-CDR) is required. Such circuit can generate local clock with the frequency and phase same as the individual received optical packet in a short locking time, for example within 40 ns. Such generated local clock can in turn perform correct data decision. Above all, the clock and data recovery can be performed correctly after a short locking time.
The conventionally used PLL based clock recovery schemes can not meet such strict requirement on locking time. Various other schemes have been invented, including those employing gated oscillator or injection locked oscillator.
References
Clock signal
Electrical circuits | Burst mode clock and data recovery | [
"Engineering"
] | 435 | [
"Electrical engineering",
"Electronic engineering",
"Electrical circuits"
] |
13,625,222 | https://en.wikipedia.org/wiki/MULTICOM | In U.S. and Canadian aviation, MULTICOM is a frequency allocation used as a Common Traffic Advisory Frequency (CTAF) by aircraft near airports where no air traffic control is available. Frequency allocations vary from region to region.
Despite the use of uppercase letters, MULTICOM is not an abbreviation or acronym.
In the United States, there is one MULTICOM frequency: 122.9 MHz. (See AIM table 4-1-2 or AIM table 4-1-1) At uncontrolled airports without a UNICOM, pilots are to self-announce on the MULTICOM frequency.
In Australia, there is one MULTICOM frequency: 126.7 MHz.
In Brazil, there is one MULTICOM frequency: 123.45 MHz.
See also
UNICOM
CTAF
Airbands
Aviation communications
Avionics
Air traffic control | MULTICOM | [
"Technology"
] | 173 | [
"Avionics",
"Aircraft instruments"
] |
13,625,345 | https://en.wikipedia.org/wiki/Schr%C3%B6dinger%20field | In quantum mechanics and quantum field theory, a Schrödinger field, named after Erwin Schrödinger, is a quantum field which obeys the Schrödinger equation. While any situation described by a Schrödinger field can also be described by a many-body Schrödinger equation for identical particles, the field theory is more suitable for situations where the particle number changes.
A Schrödinger field is also the classical limit of a quantum Schrödinger field, a classical wave which satisfies the Schrödinger equation. Unlike the quantum mechanical wavefunction, if there are interactions between the particles the equation will be nonlinear. These nonlinear equations describe the classical wave limit of a system of interacting identical particles.
The path integral of a Schrödinger field is also known as a coherent state path integral, because the field itself is an annihilation operator whose eigenstates can be thought of as coherent states of the harmonic oscillations of the field modes.
Schrödinger fields are useful for describing Bose–Einstein condensation, the Bogolyubov–de Gennes equation of superconductivity, superfluidity, and many-body theory in general. They are also a useful alternative formalism for nonrelativistic quantum mechanics.
A Schrödinger field is the nonrelativistic limit of a Klein–Gordon field.
Summary
A Schrödinger field is a quantum field whose quanta obey the Schrödinger equation. In the classical limit, it can be understood as the quantized wave equation of a Bose Einstein condensate or a superfluid.
Free field
A Schrödinger field has the free field Lagrangian
When is a complex valued field in a path integral, or equivalently an operator with canonical commutation relations, it describes a collection of identical non-relativistic bosons. When is a Grassmann valued field, or equivalently an operator with canonical anti-commutation relations, the field describes identical fermions.
External potential
If the particles interact with an external potential , the interaction makes a local contribution to the action:
The field operators obey the Euler–Lagrange equations of motion, corresponding to the Schrödinger field Lagrangian density:
Yielding the Schrödinger equations of motion:
If the ordinary Schrödinger equation for V has known energy eigenstates with energies , then the field in the action can be rotated into a diagonal basis by a mode expansion:
The action becomes:
which is the position-momentum path integral for a collection of independent Harmonic oscillators.
To see the equivalence, note that decomposed into real and imaginary parts the action is:
after an integration by parts. Integrating over gives the action
which, rescaling , is a harmonic oscillator action with frequency .
Pair potential
When the particles interact with a pair potential , the interaction is a nonlocal contribution to the action:
A pair-potential is the non-relativistic limit of a relativistic field coupled to electrodynamics. Ignoring the propagating degrees of freedom, the interaction between nonrelativistic electrons is the Coulomb repulsion. In 2+1 dimensions, this is:
When coupled to an external potential to model classical positions of nuclei, a Schrödinger field with this pair potential describes nearly all of condensed matter physics. The exceptions are effects like superfluidity, where the quantum mechanical interference of nuclei is important, and inner shell electrons where the electron motion can be relativistic.
Nonlinear Schrödinger equation
A special case of a delta-function interaction is widely studied, and is known as the nonlinear Schrödinger equation. Because the interactions always happen when two particles occupy the same point, the action for the nonlinear Schrödinger equation is local:
The interaction strength requires renormalization in dimensions higher than 2 and in two dimensions it has logarithmic divergence. In any dimensions, and even with power-law divergence, the theory is well defined. If the particles are fermions, the interaction vanishes.
Many-body potentials
The potentials can include many-body contributions. The interacting Lagrangian is then:
These types of potentials are important in some effective descriptions of close-packed atoms. Higher order interactions are less and less important.
Canonical formalism
The canonical momentum association with the field is
The canonical commutation relations are like an independent harmonic oscillator at each point:
The field Hamiltonian is
and the field equation for any interaction is a nonlinear and nonlocal version of the Schrödinger equation. For pairwise interactions:
Perturbation theory
The expansion in Feynman diagrams is called many-body perturbation theory. The propagator is
The interaction vertex is the Fourier transform of the pair-potential. In all the interactions, the number of incoming and outgoing lines is equal.
Exposition
Identical particles
The many body Schrödinger equation for identical particles describes the time evolution of the many-body wavefunction ψ(x1, x2...xN) which is the probability amplitude for N particles to have the listed positions. The Schrödinger equation for ψ is:
with Hamiltonian
Since the particles are indistinguishable, the wavefunction has some symmetry under switching
positions. Either
,
.
Since the particles are indistinguishable, the potential V must be unchanged under permutations.
If
then it must be the case that . If
then and so on.
In the Schrödinger equation formalism, the restrictions on the potential are ad-hoc, and the classical wave limit is hard to reach. It also has limited usefulness if a system is open to the environment, because particles might coherently enter and leave.
Nonrelativistic Fock space
A Schrödinger field is defined by extending the Hilbert space of states to include configurations with arbitrary particle number. A nearly complete basis for this set of states is the collection:
labeled by the total number of particles and their position. An arbitrary state with particles at separated positions is described by a superposition of states of this form.
In this formalism, keep in mind that any two states whose positions can be permuted into each other are really the same, so the integration domains need to avoid double counting. Also keep in mind that the states with more than one particle at the same point have not yet been defined. The quantity is the amplitude that no particles are present, and its absolute square is the probability that the system is in the vacuum.
In order to reproduce the Schrödinger description, the inner product on the basis states should be
and so on. Since the discussion is nearly formally identical for bosons and fermions, although the physical properties are different, from here on the particles will be bosons.
There are natural operators in this Hilbert space. One operator, called , is the operator which introduces an extra particle at x. It is defined on each basis state:
with slight ambiguity when a particle is already at x.
Another operator removes a particle at x, and is called . This operator is the conjugate of the operator . Because has no matrix elements which connect to states with no particle at x, must give zero when acting on such a state.
The position basis is an inconvenient way to understand coincident particles because states with a particle localized at one point have infinite energy, so intuition is difficult. In order to see what happens when two particles are at exactly the same point, it is mathematically simplest either to make space into a discrete lattice, or to Fourier transform the field in a finite volume.
The operator
creates a superposition of one particle states in a plane wave state with momentum k, in other words, it produces a new particle with momentum k. The operator
annihilates a particle with momentum k.
If the potential energy for interaction of infinitely distant particles vanishes, the Fourier transformed operators in infinite volume create states which are noninteracting. The states are infinitely spread out, and the chance that the particles are nearby is zero.
The matrix elements for the operators between non-coincident points reconstructs the matrix elements of the Fourier transform between all modes:
where the delta function is either the Dirac delta function or the Kronecker delta, depending on whether the volume is infinite or finite.
The commutation relations now determine the operators completely, and when the spatial volume is finite, there are no conceptual hurdle to understand coinciding momenta because momenta are discrete. In a discrete momentum basis, the basis states are:
where the n's are the number of particles at each momentum. For fermions and anyons, the number of particles at any momentum is always either zero or one. The operators have harmonic-oscillator like matrix elements between states, independent of the interaction:
So that the operator
counts the total number of particles.
Now it is easy to see that the matrix elements of and have harmonic oscillator commutation relations too.
So that there really is no difficulty with coincident particles in position space.
The operator which removes and replaces a particle, acts as a sensor to detect if a particle is present at x. The operator acts to multiply the state by the gradient of the many body wavefunction. The operator
acts to reproduce the right hand side of the Schrödinger equation when acting on any basis state, so that
holds as an operator equation. Since this is true for an arbitrary state, it is also true without the .
To add interactions, add nonlinear terms in the field equations. The field form automatically ensures that the potentials obey the restrictions from symmetry.
Field Hamiltonian
The field Hamiltonian which reproduces the equations of motion is
The Heisenberg equations of motion for this operator reproduces the equation of motion for the field.
To find the classical field Lagrangian, apply a Legendre transform to the classical limit of the Hamiltonian.
Although this is correct classically, the quantum mechanical transformation is not completely conceptually straightforward because the path integral is over eigenvalues of operators ψ which are not hermitian and whose eigenvectors are not orthogonal. The path integral over field states therefore seems naively to be overcounting. This is not the case, because the time derivative term in L includes the overlap between the different field states.
Relation to Klein–Gordon field
The non-relativistic limit as of any Klein–Gordon field is two Schrödinger fields, representing the particle and anti-particle. For clarity, all units and constants are preserved in this derivation. From the momentum space annihilation operators of the relativistic field, one defines
,
such that . Defining two "non-relativistic" fields and ,
,
which factor out a rapidly oscillating phase due to the rest mass plus a vestige of the relativistic measure, the Lagrangian density becomes
where terms proportional to are represented with ellipses and disappear in the non-relativistic limit. When the four-gradient is expanded, the total divergence is ignored and terms proportional to also disappear in the non-relativistic limit. After an integration by parts,
The final Lagrangian takes the form
Notes
References
Field
Quantum field theory | Schrödinger field | [
"Physics"
] | 2,343 | [
"Quantum field theory",
"Equations of physics",
"Eponymous equations of physics",
"Quantum mechanics",
"Schrödinger equation"
] |
13,625,403 | https://en.wikipedia.org/wiki/Radium%20Dial%20Company | The Radium Dial Company was one of a few now defunct United States companies, along with the United States Radium Corporation, involved in the painting of clocks, watches and other instrument dials using radioluminescent paint containing radium. The resulting dials are now collectively known as radium dials. The luminous paint used on the dials contained a mixture of zinc sulfide activated with silver, and powdered radium, a product that the Radium Dial Company named Luma. However, unlike the US Radium Corporation, Radium Dial Company was specifically set up to only paint dials, and no other radium processing took place at the premises.
The company is notable for being involved in the radium poisoning of the Radium Girls. The workers in the factories were told that the radium paint was harmless. Radium's negative health effects were well-known at the time, however it was thought that small amounts of radium were not dangerous and even a cure for lack of energy. The workers in the factories consumed deadly amounts of radium due to being told by management to "point" their brushes on their lips for a fine tip. The young workers also used the radium paints to adorn their fingernails, lips and teeth to make them glow. This led to significant health problems and deaths among the company's workforce. The workers eventually sued Radium Dial Company and received financial compensation for their health problems, though the Radium Dial Company continuously appealed so this process took years and many workers had already died of their injuries. This litigation led to significant reforms in workplace safety and eventually led to the establishment of OSHA decades later.
History
The Radium Dial Company was started in 1917 and was in full production of painted dials by 1918. The company was a division of the Standard Chemical Company based in the Marshall Field Annex building in Chicago. In 1920 the company relocated to Peru, Illinois to closer proximity to the clock manufacturer and major customer, Westclox.
By 1922 the company had moved to a former high school building at 1022 Columbus Street in Ottawa, Illinois where it remained until the mid-1930s. At the highest point in production (around 1925), the Radium Dial Company employed around 1,000 young women who turned out around 4,300 dials each day.
The company was headed by Joseph A. Kelly Sr. at the time of its dissolution during the trial. Kelly opened up a new corporation called Luminous Processes Inc. a few blocks away from the Radium Dial Company in Ottawa, Illinois shortly after closing down the Radium Dial Company. Luminous Processes Inc. continued producing fluorescent watch dials powered by radium radioactivity until 1978.
See also
Radium Girls
Radium jaw
Radioluminescence
References
Radium in Humans: A review of US Studies
Petitioned Public Health Assessment, Ottawa Radiation Areas, Ottawa, LaSalle County, Illinois
Film Festival; A View of the Radium Dial Horror
Nuclear safety and security
Radium
Radioactivity
American companies established in 1917
Manufacturing companies established in 1917
1917 establishments in Illinois
Defunct manufacturing companies based in Illinois | Radium Dial Company | [
"Physics",
"Chemistry"
] | 622 | [
"Radioactivity",
"Nuclear physics"
] |
13,626,384 | https://en.wikipedia.org/wiki/Pseudo-modal%20energies | Pseudo-modal energies are used for estimating the energy content of a mechanical system near its resonance frequencies. They are defined as the integral of the frequency response function within a certain bandwidth around a resonance.
References
Oscillation
Mechanics | Pseudo-modal energies | [
"Physics",
"Engineering"
] | 48 | [
"Mechanics",
"Mechanical engineering",
"Oscillation"
] |
13,626,675 | https://en.wikipedia.org/wiki/Core77 | Core77 is an online design magazine that covers the field of industrial design.
The site began as the graduate thesis of Stuart Constantine and Eric Ludlum in their final year at Brooklyn, New York's Pratt Institute. The site was launched in March 1995 and has been updated on a monthly basis since. It was first hosted at Interport, an early ISP in New York City; later it moved to its own domain.
Core77 referred to by The New York Times, Fast Company, and PC Magazine. The site also hosts an annual Core77 Design Awards competition to reward excellence in the field of design.
References
External links
Core77 Website
Design magazines
Industrial design
Magazines established in 1995
Magazines published in New York City
Online magazines published in the United States
Visual arts magazines published in the United States | Core77 | [
"Engineering"
] | 164 | [
"Industrial design",
"Design magazines",
"Design",
"Design engineering"
] |
13,628,958 | https://en.wikipedia.org/wiki/Beta-globin%20co-transcriptional%20cleavage%20ribozyme | The Beta-globin co-transcriptional cleavage ribozyme (CotC ribozyme) was proposed to be an RNA enzyme known as a ribozyme.
Transcription termination of RNA polymerase II transcripts is proposed to occur by a two-stage process. The first stage involves pre-termination cleavage (PTC) of the nascent transcript downstream of the poly(A) site. This process is also referred to as co-transcriptional cleavage (CoTC). The CoTC process in the human beta-globin gene was proposed to involve an RNA self-cleaving activity located in the 3' flanking region of the beta-globin gene. The CoTC core is highly conserved in the 3' UTR of other primate beta-globin genes.
However, there has been no independent confirmation of these findings, and a subsequent analysis by a team including members of the original report failed to demonstrate ribozyme activity.
References
External links
Non-coding RNA
Ribozymes
RNA splicing | Beta-globin co-transcriptional cleavage ribozyme | [
"Chemistry"
] | 212 | [
"Catalysis",
"Molecular and cellular biology stubs",
"Biochemistry stubs",
"Chemical reaction stubs",
"Ribozymes",
"Chemical process stubs"
] |
13,629,226 | https://en.wikipedia.org/wiki/Gurken%20localisation%20signal | mRNA localization is a common mode of posttranscriptional regulation of gene expression that targets a protein to its site of function.
Proteins are highly dependent on cellular environments for stability and function, therefore, mRNA localization signals are crucial for maintaining protein function. The Gurken localisation signal is an RNA regulatory element conserved across many species of Drosophila. The element consists of an RNA stem loop within the coding region of the messenger RNA that forms a signal for dynein-mediated Gurken mRNA transport to the dorsoanterior cap near the nucleus of the oocyte.
Mechanism of action
During Drosophila oogenesis, signaling between the germline and the soma leads to the establishment of anterior-posterior polarity in the egg and the embryo. This process involves the interaction of gurken (grk), a TGFα-like protein, with torpedo (top), the Drosophila epidermal growth factor receptor (EGFR). Localization of gurken RNA defines cell morphology by regulating the distribution of the gurken protein. Gurken mRNA transcripts which are not localized to the dorsal-anterior of an oocyte become silenced via post-translational modifications. Post-translational modifications of gurken protein have been observed to determine the protein's localization and function. Polyadenylation of gurken transcripts occur throughout oogenesis; the length of the poly(A) tail determines the stage in oogenesis at which the gurken protein is adenylated. 30-50 gurken adenlyated residues are associated in initial oogenesis whilst 50-90 adenlyated residues are associated with late-stage oogenesis.
The major difference between the gurken localization signal and other localization signals is that gurken localization signals are distributed throughout coding regions, whereas the majority of the other localization signals are found in 3' untranslated regions.[9]. The gurken localization signal does not function properly if it is located in the 3' untranslated region.
References
External links
Cis-regulatory RNA elements | Gurken localisation signal | [
"Chemistry"
] | 445 | [
"Biochemistry stubs",
"Molecular and cellular biology stubs"
] |
13,629,231 | https://en.wikipedia.org/wiki/Hepatitis%20C%20alternative%20reading%20frame%20stem-loop | Hepatitis C alternative reading frame stem-loop is a conserved secondary structure motif identified in the RNA genome of the hepatitis C virus (HCV) which is proposed to have an important role in regulating translation and repression of the viral genome.
The core protein-coding region of the hepatitis C virus (HCV) genome contains a +1 alternative reading frame (ARF) and two proposed phylogenetically conserved RNA helix-forming stem loop structures (IV and VII).
The proteins translated from the ARF appear to be translated during the normal viral life cycle but are not essential to virus replication. The two predicted stem loops shown here (SLV and SLVI) are proposed to be important for HCV translation and repression; these stem loops are located downstream of the internal ribosome entry site (IRES) but their functional role is unknown.
See also
Hepatitis E virus cis-reactive element
References
External links
Cis-regulatory RNA elements
Hepatitis C virus | Hepatitis C alternative reading frame stem-loop | [
"Chemistry"
] | 190 | [
"Biochemistry stubs",
"Molecular and cellular biology stubs"
] |
13,629,244 | https://en.wikipedia.org/wiki/Listeria%20Hfq%20binding%20LhrA | Listeria Hfq binding LhrA is a ncRNA that was identified by screening for RNA molecules which co-immunoprecipitated with the RNA chaperone Hfq. This RNA is transcribed from a region overlapping with a predicted protein of unknown function (Lmo2257) and is located between a putative intracellular protease and a putative protein of the ribulose-phosphate 3 epimerase family. It is highly expressed in the stationary growth phase but the function is unknown. It is proposed to be a regulatory RNA which controls gene expression at the post transcriptional level by binding the target mRNA in an Hfq dependent fashion. This RNA molecule appears to be conserved amongst Listeria species but has not been identified in other bacterial species.
See also
Listeria Hfq binding LhrC
References
External links
Non-coding RNA | Listeria Hfq binding LhrA | [
"Chemistry"
] | 178 | [
"Biochemistry stubs",
"Molecular and cellular biology stubs"
] |
13,629,249 | https://en.wikipedia.org/wiki/Listeria%20Hfq%20binding%20LhrC | Listeria LhrC ncRNA was identified by screening for RNA molecules which co-immunoprecipitated with the RNA chaperone Hfq. However, neither the stability nor the activity of LhrC seem to depend on the presence of Hfq. This RNA is transcribed from an intergenic region between the protein coding genes cysK, a putative cysteine synthase and sul, a putative dihydropteroate synthase. In Listeria monocytogenes four additional copies of lhrC have been identified in the genome, three of which are located in tandem repeat upstream of the originally characterised lhrC. This RNA molecule appears to be conserved amongst Listeria species but has not been identified in other bacterial species. It is involved in virulence. The direct mRNA targets of LhrC are the virulence adhesion LapB, and the oligopeptide binding protein OppA. The 3 conserved UCCC motifs common to all copies of LhrC are involved in the mRNA binding and post-transcriptional repression of the target genes. Two other Listerina monocytogenes sRNAs Rli22 and Rli33 contain 2 UCCC motifs and use them to repress oppA mRNA expression.
See also
Listeria Hfq binding LhrA
References
External links
Non-coding RNA | Listeria Hfq binding LhrC | [
"Chemistry"
] | 279 | [
"Biochemistry stubs",
"Molecular and cellular biology stubs"
] |
13,629,255 | https://en.wikipedia.org/wiki/Mammalian%20CPEB3%20ribozyme | The mammalian CPEB3 ribozyme is a self cleaving non-coding RNA located in the second intron of the CPEB3 gene which belongs to a family of genes regulating messenger RNA polyadenylation. This ribozyme is highly conserved and
found only in mammals. The CPEB3 ribozyme is structurally and biochemically related to the human hepatitis delta virus ribozyme. Other HDV-like ribozymes have been identified and confirmed to be active in vitro in a number of eukaryotes.
References
External links
Non-coding RNA
Ribozymes
RNA splicing | Mammalian CPEB3 ribozyme | [
"Chemistry"
] | 127 | [
"Catalysis",
"Molecular and cellular biology stubs",
"Biochemistry stubs",
"Chemical reaction stubs",
"Ribozymes",
"Chemical process stubs"
] |
13,629,264 | https://en.wikipedia.org/wiki/Pseudomonas%20sRNA%20P1 | Pseudomonas sRNA P1 is a ncRNA that was predicted using bioinformatic tools in the genome of the opportunistic pathogen Pseudomonas aeruginosa and its expression verified by northern blot analysis.
There appears to be two related copies of P1 sRNA in the P. aeruginosa PA01 genome and both copies appear to be located upstream of predicted glutamine synthetase genes. This sRNA appears to be conserved amongst several Pseudomonas species. P1 has a predicted Rho independent terminator at the 3′ end but the function of P1 is unknown.
See also
Pseudomonas sRNA P9
Pseudomonas sRNA P11
Pseudomonas sRNA P15
Pseudomonas sRNA P16
Pseudomonas sRNA P24
Pseudomonas sRNA P26
References
External links
Non-coding RNA | Pseudomonas sRNA P1 | [
"Chemistry"
] | 180 | [
"Biochemistry stubs",
"Molecular and cellular biology stubs"
] |
13,629,271 | https://en.wikipedia.org/wiki/Pseudomonas%20sRNA%20P11 | Pseudomonas sRNA P11 is a ncRNA that was predicted using bioinformatic tools in the genome of the opportunistic pathogen Pseudomonas aeruginosa and its expression verified by northern blot analysis. P11 is located between a putative threonine protein kinase and putative nitrate reductase and is conserved in several Pseudomonas species. P11 has a predicted Rho independent terminator at the 3′ end but the function of P11 is unknown.
See also
Pseudomonas sRNA P1
Pseudomonas sRNA P9
Pseudomonas sRNA P15
Pseudomonas sRNA P16
Pseudomonas sRNA P24
Pseudomonas sRNA P26
References
External links
Non-coding RNA | Pseudomonas sRNA P11 | [
"Chemistry"
] | 155 | [
"Biochemistry stubs",
"Molecular and cellular biology stubs"
] |
13,629,275 | https://en.wikipedia.org/wiki/Pseudomonas%20sRNA%20P15 | Pseudomonas sRNA P15 is a ncRNA that was predicted using bioinformatic tools in the genome of the opportunistic pathogen Pseudomonas aeruginosa and its expression verified by northern blot analysis.
P15 is conserved across several Pseudomonas species and is consistently located upstream of a 3-deoxy-7-phosphoheptulonate synthase gene. P15 has a predicted Rho independent terminator at the 3′ end but the function of P15 is unknown.
See also
Pseudomonas sRNA P1
Pseudomonas sRNA P9
Pseudomonas sRNA P11
Pseudomonas sRNA P16
Pseudomonas sRNA P24
Pseudomonas sRNA P26
References
External links
Non-coding RNA | Pseudomonas sRNA P15 | [
"Chemistry"
] | 160 | [
"Biochemistry stubs",
"Molecular and cellular biology stubs"
] |
13,629,277 | https://en.wikipedia.org/wiki/Pseudomonas%20sRNA%20P16 | Pseudomonas sRNA P16 is a ncRNA that was predicted using bioinformatic tools in the genome of the opportunistic pathogen Pseudomonas aeruginosa and its expression verified by northern blot analysis. P16 sRNA appears to be conserved across several Pseudomonas species and is consistently located downstream of a predicted TatD deoxyribonuclease gene. P16 has a predicted Rho independent terminator at the 3′ end but the function of P16 is unknown.
It has been shown that this sRNA is transcribed from an RpoS-dependent promoter under positive, probably indirect GacA control in two Pseudomonas species. It was renamed RgsA (for regulation by GacA and stress). RpoS mRNA expression is repressed by RgsA during the exponential phase. The Hfq RNA chaperone is required for the repression.
See also
Pseudomonas sRNA P1
Pseudomonas sRNA P9
Pseudomonas sRNA P11
Pseudomonas sRNA P15
Pseudomonas sRNA P24
Pseudomonas sRNA P26
References
External links
Non-coding RNA | Pseudomonas sRNA P16 | [
"Chemistry"
] | 239 | [
"Biochemistry stubs",
"Molecular and cellular biology stubs"
] |
13,629,296 | https://en.wikipedia.org/wiki/Pseudomonas%20sRNA%20P24 | Pseudomonas sRNA P24 is a ncRNA that was predicted using bioinformatic tools in the genome of the opportunistic pathogen Pseudomonas aeruginosa and its expression verified by northern blot analysis.
P24 is conserved across several Pseudomonas species and is consistently located between a hypothetical protein gene and a transcriptional regulator gene (AsnC family) in the genomes of these Pseudomonas species. P24 has a predicted Rho independent terminatorat the 3′ end but the function of P24 is unknown.
See also
Pseudomonas sRNA P9
Pseudomonas sRNA P11
Pseudomonas sRNA P15
Pseudomonas sRNA P16
Pseudomonas sRNA P26
References
External links
Non-coding RNA | Pseudomonas sRNA P24 | [
"Chemistry"
] | 158 | [
"Biochemistry stubs",
"Molecular and cellular biology stubs"
] |
13,629,304 | https://en.wikipedia.org/wiki/Pseudomonas%20sRNA%20P26 | Pseudomonas sRNA P26 is a ncRNA that was predicted using bioinformatic tools in the genome of the opportunistic pathogen Pseudomonas aeruginosa and its expression verified by northern blot analysis. P26 is conserved across many Gammaproteobacteria species and appears to be consistently located between the DNA directed RNA polymerase (beta subunit) and 50S ribosomal protein L7/L12 genes.
See also
Pseudomonas sRNA P9
Pseudomonas sRNA P11
Pseudomonas sRNA P15
Pseudomonas sRNA P16
Pseudomonas sRNA P24
Pseudomonas sRNA P1
References
External links
Non-coding RNA | Pseudomonas sRNA P26 | [
"Chemistry"
] | 143 | [
"Biochemistry stubs",
"Molecular and cellular biology stubs"
] |
13,629,307 | https://en.wikipedia.org/wiki/Pseudomonas%20sRNA%20P9 | Pseudomonas sRNA P9 is a ncRNA that was predicted using bioinformatic tools in the genome of the opportunistic pathogen Pseudomonas aeruginosa and its expression verified by northern blot analysis.
P9 appears to be conserved in several Pseudomonas species in addition to Bordetella species. In both Pseudomonas and Bordetella species P9 appears to be located upstream of a predicted threonine dehydratase gene. P9 has a predicted Rho independent terminator at the 3′ end but the function of P9 is unknown.
See also
Pseudomonas sRNA P1
Pseudomonas sRNA P11
Pseudomonas sRNA P15
Pseudomonas sRNA P16
Pseudomonas sRNA P24
Pseudomonas sRNA P26
References
External links
Non-coding RNA | Pseudomonas sRNA P9 | [
"Chemistry"
] | 176 | [
"Biochemistry stubs",
"Molecular and cellular biology stubs"
] |
13,629,313 | https://en.wikipedia.org/wiki/Small%20Cajal%20body%20specific%20RNA%2020 | In molecular biology, Small Cajal body specific RNA 20 (also known as scaRNA20 or ACA66) is a small nucleolar RNA found in Cajal bodies and believed to be involved in the pseudouridylation of U12 minor spliceosomal RNA.
scaRNAs are a specific class of small nucleolar RNAs that localise to the Cajal bodies and guide the modification of RNA polymerase II transcribed spliceosomal RNAs U1, U2, U4, U5 and U12.
ACA66 (SCARNA20) is a member of the H/ACA box class of snoRNAs that guide the sites of modification of uridines to pseudouridines. This snoRNA was identified by computational screening and its expression in mouse experimentally verified by Northern blot and primer extension analysis.
ACA66 is predicted to guide the pseudouridylation of residue U28 in U12 snRNA.
References
External links
Non-coding RNA
Spliceosome
RNA splicing | Small Cajal body specific RNA 20 | [
"Chemistry"
] | 211 | [
"Biochemistry stubs",
"Molecular and cellular biology stubs"
] |
13,629,314 | https://en.wikipedia.org/wiki/Starling%20resistor | The Starling resistor was invented by English physiologist Ernest Starling and used in an isolated-heart preparation during work which would later lead to the "Frank–Starling law of the heart".
The device consisted of an elastic fluid-filled collapsible-tube mounted inside a chamber filled with air. The static pressure inside the chamber was used to control the degree of collapse of the tube, so providing a variable resistor. This resistance was used to simulate TPR, or total peripheral (vascular) resistance.
Starling resistors have been used both as an instrument in the study of interesting physiological phenomena (e.g. pharyngeal collapse during obstructed breathing or OSA) and as a rich source of physical phenomena in their own right. Two non-linear behaviours are characteristic: 1) the “waterfall effect” wherein, subsequent to collapse, the flow through the tube becomes independent of the downstream pressure and 2) self-excited oscillations. Expiratory flow-limitation in the disease COPD is an example of the former behaviour and snoring an example of the latter.
References
Biomedical engineering | Starling resistor | [
"Engineering",
"Biology"
] | 237 | [
"Biological engineering",
"Bioengineering stubs",
"Biomedical engineering",
"Biotechnology stubs",
"Medical technology stubs",
"Medical technology"
] |
13,629,315 | https://en.wikipedia.org/wiki/Small%20Cajal%20body%20specific%20RNA%2021 | In molecular biology, Small Cajal body specific RNA 21 (also known as scaRNA21 or ACA68) is a small nucleolar RNA found in Cajal bodies and believed to be involved in the pseudouridylation of U12 minor spliceosomal RNA.
scaRNAs are a specific class of small nucleolar RNAs that localise to the Cajal bodies and guide the modification of RNA polymerase II transcribed spliceosomal RNAs U1, U2, U4, U5 and U12.
ACA68 (SCARNA21) is a member of the H/ACA box class of snoRNAs that guide the sites of modification of uridines to pseudouridines. This snoRNA was identified by computational screening and its expression in mouse experimentally verified by Northern blot and primer extension analysis.
ACA68 is proposed to guide the pseudouridylation of residue U19 in U12 snRNA.
References
External links
Non-coding RNA
Small nuclear RNA
Spliceosome
RNA splicing | Small Cajal body specific RNA 21 | [
"Chemistry"
] | 217 | [
"Biochemistry stubs",
"Molecular and cellular biology stubs"
] |
13,629,331 | https://en.wikipedia.org/wiki/Small%20nucleolar%20RNA%20SNORD100 | In molecular biology, Small Nucleolar RNA SNORD100 (also known as HBII-429) is a non-coding RNA (ncRNA) molecule which functions in the biogenesis (modification) of other small nuclear RNAs (snRNAs). This type of modifying RNA is located in the nucleolus of the eukaryotic cell which is a major site of snRNA biogenesis. It is known as a small nucleolar RNA (snoRNA) and also often referred to as a guide RNA.
SNORD100 belongs to the C/D box class of snoRNAs which contain the C (UGAUGA) and D (CUGA) box motifs. Most of the members of the C/D box family function in directing site-specific 2'-O-methylation of substrate RNAs.
SNORD100 is predicted to guide the 2'O-ribose methylation of 18S ribosomal RNA (rRNA) at residue G436.
References
External links
Non-coding RNA | Small nucleolar RNA SNORD100 | [
"Chemistry"
] | 218 | [
"Biochemistry stubs",
"Molecular and cellular biology stubs"
] |
13,629,333 | https://en.wikipedia.org/wiki/Small%20nucleolar%20RNA%20SNORD110 | In molecular biology, Small Nucleolar RNA SNORD110 (also known as HBII-55) is a non-coding RNA (ncRNA) molecule which functions in the biogenesis (modification) of other small nuclear RNAs (snRNAs). This type of modifying RNA is located in the nucleolus of the eukaryotic cell which is a major site of snRNA biogenesis. It is known as a small nucleolar RNA (snoRNA) and also often referred to as a guide RNA.
HBII-55 belongs to the C/D box class of snoRNAs which contain the C (UGAUGA) and D (CUGA) box motifs. Most of the members of the box C/D family function in directing site-specific 2′-O-methylation of substrate RNAs. HBII-55 is predicted to guide the 2′O-ribose methylation of 18S ribosomal RNA (rRNA) at residue U1288.
References
External links
Non-coding RNA | Small nucleolar RNA SNORD110 | [
"Chemistry"
] | 221 | [
"Biochemistry stubs",
"Molecular and cellular biology stubs"
] |
13,629,346 | https://en.wikipedia.org/wiki/Small%20nucleolar%20RNA%20SNORD111 | In molecular biology, Small Nucleolar RNA SNORD111 (also known as HBII-82) is a non-coding RNA (ncRNA) molecule which functions in the biogenesis (modification) of other small nuclear RNAs (snRNAs). This type of modifying RNA is located in the nucleolus of the eukaryotic cell which is a major site of snRNA biogenesis. It is known as a small nucleolar RNA (snoRNA) and also often referred to as a guide RNA.
SNORD111 belongs to the C/D box class of snoRNAs which contain the C (UGAUGA) and D (CUGA) box motifs. Most of the members of the box C/D family function in directing site-specific 2′-O-methylation of substrate RNAs.
SNORD111 is predicted to guide the 2′O-ribose methylation of 28S ribosomal RNA (rRNA) at residue G3923.
The exact role of these molecules, however, is not currently known.
References
External links
Non-coding RNA | Small nucleolar RNA SNORD111 | [
"Chemistry"
] | 234 | [
"Biochemistry stubs",
"Molecular and cellular biology stubs"
] |
13,629,352 | https://en.wikipedia.org/wiki/Small%20nucleolar%20RNA%20SNORD93 | In molecular biology, Small Nucleolar RNA SNORD93 (also known as HBII-336) is a non-coding RNA (ncRNA) molecule that functions in the biogenesis (modification) of other small nuclear RNAs (snRNAs). This type of modifying RNA is located in the nucleolus of the Eukaryotic cell which is a major site of snRNA biogenesis. It is known as a small nucleolar RNA (snoRNA) and is also often referred to as a guide RNA.
SNORD93 belongs to the C/D box class of snoRNAs which contain the C (UGAUGA) and D (CUGA) box motifs. Most of the members of the box C/D family function in directing site-specific 2'-O-methylation of substrate RNAs. This snoRNA is the human orthologue of mouse snoRNA MBII-336.
SNORD93 is predicted to guide the 2'O-ribose methylation of 18S ribosomal RNA (rRNA) residue A576.
Additionally, SNORD93 can be processed into a smaller, microRNA-like fragment (termed snoRNA-derived RNA(sdRNA)) that contributes to the malignant phenotype of breast cancer.
The processed piece (sdRNA-93) has been shown to target Pipox, a sarcosine metabolism-related protein whose expression significantly correlates with distinct molecular subtypes of breast cancer.
References
External links
Non-coding RNA | Small nucleolar RNA SNORD93 | [
"Chemistry"
] | 327 | [
"Biochemistry stubs",
"Molecular and cellular biology stubs"
] |
13,629,356 | https://en.wikipedia.org/wiki/Small%20nucleolar%20RNA%20SNORD94 | In molecular biology, Small Nucleolar RNA SNORD94 (also known as U94) is a non-coding RNA (ncRNA) molecule which functions in the biogenesis (modification) of other small nuclear RNAs (snRNAs). This type of modifying RNA is located in the nucleolus of the eukaryotic cell which is a major site of snRNA biogenesis. It is known as a small nucleolar RNA (snoRNA) and also often referred to as a guide RNA.
SNOR94 is a member of the C/D box class of snoRNAs which contain the conserved sequence motifs known as the C box (UGAUGA) and the D box (CUGA). Most of the members of the box C/D family function in directing site-specific 2'-O-methylation of substrate RNAs. SNORD94 is predicted to guide the 2'O-ribose methylation of C62 of the snRNA U6.
References
External links
Non-coding RNA | Small nucleolar RNA SNORD94 | [
"Chemistry"
] | 222 | [
"Biochemistry stubs",
"Molecular and cellular biology stubs"
] |
13,629,361 | https://en.wikipedia.org/wiki/Small%20nucleolar%20RNA%20SNORD98 | In molecular biology, Small Nucleolar RNA SNORD98 (also known as HBII-419) is a non-coding RNA (ncRNA) molecule which functions in the biogenesis (modification) of other small nuclear RNAs (snRNAs). This type of modifying RNA is located in the nucleolus of the eukaryotic cell which is a major site of snRNA biogenesis. It is known as a small nucleolar RNA (snoRNA) and also often referred to as a guide RNA.
SNORD98 belongs to the C/D box class of snoRNAs which contain the C (UGAUGA) and D (CUGA) box motifs. Most of the members of the box C/D family function in directing site-specific 2′-O-methylation of substrate RNAs.
SNORD98 is predicted to guide the 2'0-ribose methylation of 18S ribosomal RNA (rRNA) residue G867.
References
External links
Non-coding RNA | Small nucleolar RNA SNORD98 | [
"Chemistry"
] | 220 | [
"Biochemistry stubs",
"Molecular and cellular biology stubs"
] |
13,629,364 | https://en.wikipedia.org/wiki/Small%20nucleolar%20RNA%20SNORD99 | In molecular biology, Small Nucleolar RNA SNORD99 (also known as HBII-420) is a non-coding RNA (ncRNA) molecule which functions in the biogenesis (modification) of other small nuclear RNAs (snRNAs). This type of modifying RNA is located in the nucleolus of the eukaryotic cell which is a major site of snRNA biogenesis. It is known as a small nucleolar RNA (snoRNA) and also often referred to as a guide RNA.
SNORD99 belongs to the C/D box class of snoRNAs which contain the C (UGAUGA) and D (CUGA) box motifs. Most of the members of the box C/D family function in directing site-specific 2'-O-methylation of substrate RNAs. SNORD99 is predicted to guide the 2'O-ribose methylation of 28S ribosomal RNA at residue A2774. In the human genome this snoRNA shares the same host gene with the three H/ACA box snoRNAs ACA16, ACA44 and ACA61.
References
External links
Non-coding RNA | Small nucleolar RNA SNORD99 | [
"Chemistry"
] | 254 | [
"Biochemistry stubs",
"Molecular and cellular biology stubs"
] |
13,629,372 | https://en.wikipedia.org/wiki/Small%20nucleolar%20RNA%20SNORA11 | In molecular biology, small nucleolar RNA SNORA11 (also known as U107) is a non-coding RNA (ncRNA) molecule which functions in the biogenesis (modification) of other small nuclear RNAs (snRNAs). This type of modifying RNA is located in the nucleolus of the eukaryotic cell which is a major site of snRNA biogenesis. It is known as a small nucleolar RNA (snoRNA).
U107 has a predicted hairpin-hinge-hairpin-tail structure and is predicted to be a member of the H/ACA box class of snoRNAs that guide the sites of modification of uridines to pseudouridines.
This snoRNA was identified by RT-PCR from blood cells and its expression confirmed by Northern blot analysis.
There is no predicted RNA target for this guide snRNA.
References
External links
HGNC page for Small nucleolar RNA SNORA11
Non-coding RNA | Small nucleolar RNA SNORA11 | [
"Chemistry"
] | 213 | [
"Biochemistry stubs",
"Molecular and cellular biology stubs"
] |
13,629,379 | https://en.wikipedia.org/wiki/Small%20nucleolar%20RNA%20SNORA77 | In molecular biology, Small nucleolar RNA SNORA77 (also known as ACA63) is a non-coding RNA (ncRNA) molecule which functions in the biogenesis (modification) of other small nuclear RNAs (snRNAs). This type of modifying RNA is located in the nucleolus of the eukaryotic cell which is a major site of snRNA biogenesis. It is known as a small nucleolar RNA (snoRNA).
SNORA77 was identified by computational screening and its expression in mouse experimentally verified by Northern blot and primer extension analysis.
It belongs to the H/ACA box class of snoRNAs as it has the predicted hairpin-hinge-hairpin-tail structure and conserved H/ACA-box motifs.
SNORA77 is proposed to guide the pseudouridylation of 18S ribosomal RNA (rRNA) residue U814.
Pseudouridylation is the isomerisation of the nucleoside uridine to the different isomeric form pseudouridine.
References
External links
Non-coding RNA | Small nucleolar RNA SNORA77 | [
"Chemistry"
] | 237 | [
"Biochemistry stubs",
"Molecular and cellular biology stubs"
] |
13,629,382 | https://en.wikipedia.org/wiki/Small%20nucleolar%20RNA%20SNORA79 | In molecular biology, Small nucleolar RNA SNORA79 (also known as ACA65) is a non-coding RNA (ncRNA) molecule which functions in the biogenesis (modification) of other small nuclear RNAs (snRNAs). This type of modifying RNA is located in the nucleolus of the eukaryotic cell which is a major site of snRNA biogenesis. It is known as a small nucleolar RNA (snoRNA).
SNORA79 was identified by computational screening and its expression in mouse experimentally verified by Northern blot and primer extension analysis.
It belongs to the H/ACA box class of snoRNAs as it has the predicted hairpin-hinge-hairpin-tail structure and the conserved H/ACA-box motifs.
SNORA79 is proposed to guide the pseudouridylation of residue U31 in U6 snRNA.
Pseudouridylation is the isomerisation of the nucleoside uridine to the different isomeric form pseudouridine.
References
External links
Small nuclear RNA | Small nucleolar RNA SNORA79 | [
"Chemistry"
] | 232 | [
"Biochemistry stubs",
"Molecular and cellular biology stubs"
] |
13,629,391 | https://en.wikipedia.org/wiki/Small%20nucleolar%20RNA%20SNORD23 | In molecular biology, Small Nucleolar RNA SNORD23 (also known as HBII-115) is a non-coding RNA (ncRNA) molecule which functions in the biogenesis (modification) of other small nuclear RNAs (snRNAs). This type of modifying RNA is located in the nucleolus of the eukaryotic cell which is a major site of snRNA biogenesis. It is known as a small nucleolar RNA (snoRNA) and also often referred to as a guide RNA.
SNORD23 belongs to the C/D box class of snoRNAs which contain the C (UGAUGA) and D (CUGA) box motifs. Most of the members of the C/D box family function in directing site-specific 2′-O-methylation of substrate RNAs.
This snoRNA is the human orthologue of mouse snoRNA MBII-115.
There is currently no predicted target RNA for SNORD23.
References
External links
Non-coding RNA | Small nucleolar RNA SNORD23 | [
"Chemistry"
] | 218 | [
"Biochemistry stubs",
"Molecular and cellular biology stubs"
] |
13,629,423 | https://en.wikipedia.org/wiki/Small%20nucleolar%20RNA%20SNORD75 | In molecular biology, Small Nucleolar RNA SNORD75 (also known as U75) is a non-coding RNA (ncRNA) molecule which functions in the biogenesis (modification) of other small nuclear RNAs (snRNAs). This type of modifying RNA is located in the nucleolus of the eukaryotic cell which is a major site of snRNA biogenesis. It is known as a small nucleolar RNA (snoRNA) and also often referred to as a guide RNA.
U75 (SNORD75) belongs to the C/D box class of snoRNAs which contain the C (UGAUGA) and D (CUGA) box motifs. Most of the members of the box C/D family function in directing site-specific 2′-O-methylation of substrate RNAs.
The mouse snoRNA Z19 is orthologous to human U75. U75 is predicted to guide the 2′-O-ribose methylation of 28S ribosomal RNA (rRNA) residue C4032.
In humans U75 shares the same non-protein coding host gene (gas5) with 9 other snoRNAs (U44, U47, U74, U76, U77, U78, U79, U80 and U81).
References
External links
Non-coding RNA | Small nucleolar RNA SNORD75 | [
"Chemistry"
] | 292 | [
"Biochemistry stubs",
"Molecular and cellular biology stubs"
] |
13,629,430 | https://en.wikipedia.org/wiki/Small%20nucleolar%20RNA%20SNORD88 | In molecular biology, Small Nucleolar RNA SNORD88 (also known as HBII-180) is a non-coding RNA (ncRNA) molecule which functions in the biogenesis (modification) of other small nuclear RNAs (snRNAs). This type of modifying RNA is located in the nucleolus of the eukaryotic cell which is a major site of snRNA biogenesis. It is known as a small nucleolar RNA (snoRNA) and also often referred to as a guide RNA.
SNORD88 belongs to the C/D box class of snoRNAs which contain the C (UGAUGA) and D (CUGA) box motifs. Most of the members of the C/D box family function in directing site-specific 2′-O-methylation of substrate RNAs.
This snoRNA is the human orthologue of mouse snoRNA MBII-180. SNORD88 is also related to mouse snoRNA MBII-211. SNORD88 is predicted to guide the 2′O-ribose methylation of 28S ribosomal RNA (rRNA) residue C3680.
There is evidence that SNORD88 is processed into smaller fragments in a similar fashion to a microRNA and can suppress protein expression.
References
External links
Non-coding RNA | Small nucleolar RNA SNORD88 | [
"Chemistry"
] | 286 | [
"Biochemistry stubs",
"Molecular and cellular biology stubs"
] |
13,629,434 | https://en.wikipedia.org/wiki/Small%20nucleolar%20RNA%20SNORD92 | In molecular biology, Small Nucleolar RNA SNORD92 (also known as HBII-316) is a non-coding RNA (ncRNA) molecule which functions in the biogenesis (modification) of other small nuclear RNAs (snRNAs). This type of modifying RNA is located in the nucleolus of the eukaryotic cell which is a major site of snRNA biogenesis. It is known as a small nucleolar RNA (snoRNA) and also often referred to as a guide RNA.
SNORD92 belongs to the C/D box class of snoRNAs which contain the C (UGAUGA) and D (CUGA) box motifs. Most of the members of the C/D box family function in directing site-specific 2′-O-methylation of substrate RNAs.
This snoRNA is the human orthologue of mouse snoRNA MBII-316.
SNORD92 is predicted to guide the 2′O-ribose methylation of 28S ribosomal RNA (rRNA) residue A3846.
References
External links
Non-coding RNA | Small nucleolar RNA SNORD92 | [
"Chemistry"
] | 240 | [
"Biochemistry stubs",
"Molecular and cellular biology stubs"
] |
13,629,438 | https://en.wikipedia.org/wiki/U4atac%20minor%20spliceosomal%20RNA | U4atac minor spliceosomal RNA is a ncRNA which is an essential component of the minor U12-type spliceosome complex. The U12-type spliceosome is required for removal of the rarer class of eukaryotic introns (AT-AC, U12-type).
U4atac snRNA is proposed to form a base-paired complex with another spliceosomal RNA U6atac via two stem loop regions. These interacting stem loops have been shown to be required for in vivo splicing. U4atac also contains a 3' Sm protein binding site which has been shown to be essential for splicing activity. U4atac is the functional analog of U4 spliceosomal RNA in the major U2-type spliceosomal complex.
The Drosophila U4atac snRNA has an additional predicted 3' stem loop terminal to the Sm binding site.
Disease
It has been shown that mutations in the U4atac snRNA can cause microcephalic osteodysplastic primordial dwarfism type I (MOPD I), also called Taybi-Linder syndrome (TALS). MOPD I is a developmental disorder that is associated with brain and skeletal abnormalities. It has been shown that the mutations cause defective U12 splicing.
References
External links
Non-coding RNA
Spliceosome
RNA splicing | U4atac minor spliceosomal RNA | [
"Chemistry"
] | 296 | [
"Biochemistry stubs",
"Molecular and cellular biology stubs"
] |
13,629,448 | https://en.wikipedia.org/wiki/U6atac%20minor%20spliceosomal%20RNA | U6atac minor spliceosomal RNA is a non-coding RNA which is an essential component of the minor U12-type spliceosome complex. The U12-type spliceosome is required for removal of the rarer class of eukaryotic introns (AT-AC, U12-type).
U6atac snRNA is proposed to form a base-paired complex with another spliceosomal RNA U4atac via two stem loop regions. These interacting stem loops have been shown to be required for in vivo splicing. U6atac is the functional analog of U6 spliceosomal RNA in
the major U2-type spliceosomal complex.
References
External links
Non-coding RNA
Spliceosome
RNA splicing
fr:ARN splicéosomal U4atac | U6atac minor spliceosomal RNA | [
"Chemistry"
] | 172 | [
"Biochemistry stubs",
"Molecular and cellular biology stubs"
] |
13,629,458 | https://en.wikipedia.org/wiki/Flavivirus%20capsid%20hairpin%20cHP | The Flavivirus capsid hairpin cHP is a conserved RNA hairpin structure identified within the capsid coding region of several flavivirus genomes. These positive strand RNA genomes are translated as a single polypeptide and subsequently cleaved into constituent proteins, the first of which is the capsid protein. The cHP hairpin is located within the capsid coding region between two AUG start codons. The cHP cis element has been shown to direct translation start from the suboptimal first start codon. The ability of cHP to direct initiation from the first start codon is proportional to its thermodynamic stability, is position dependent, and is sequence independent. It has been demonstrated that both AUGs and the conserved cHP are necessary for efficient viral replication in human and mosquito cells.
References
External links
Cis-regulatory RNA elements
Flaviviruses | Flavivirus capsid hairpin cHP | [
"Chemistry"
] | 182 | [
"Biochemistry stubs",
"Molecular and cellular biology stubs"
] |
13,629,602 | https://en.wikipedia.org/wiki/Allegory%20%28mathematics%29 | In the mathematical field of category theory, an allegory is a category that has some of the structure of the category Rel of sets and binary relations between them. Allegories can be used as an abstraction of categories of relations, and in this sense the theory of allegories is a generalization of relation algebra to relations between different sorts. Allegories are also useful in defining and investigating certain constructions in category theory, such as exact completions.
In this article we adopt the convention that morphisms compose from right to left, so means "first do , then do ".
Definition
An allegory is a category in which
every morphism is associated with an anti-involution, i.e. a morphism with and and
every pair of morphisms with common domain/codomain is associated with an intersection, i.e. a morphism
all such that
intersections are idempotent: commutative: and associative:
anti-involution distributes over intersection:
composition is semi-distributive over intersection: and and
the modularity law is satisfied:
Here, we are abbreviating using the order defined by the intersection: means
A first example of an allegory is the category of sets and relations. The objects of this allegory are sets, and a morphism is a binary relation between and . Composition of morphisms is composition of relations, and the anti-involution of is the converse relation : if and only if . Intersection of morphisms is (set-theoretic) intersection of relations.
Regular categories and allegories
Allegories of relations in regular categories
In a category , a relation between objects and is a span of morphisms that is jointly monic. Two such spans and are considered equivalent when there is an isomorphism between and that make everything commute; strictly speaking, relations are only defined up to equivalence (one may formalise this either by using equivalence classes or by using bicategories). If the category has products, a relation between and is the same thing as a monomorphism into (or an equivalence class of such). In the presence of pullbacks and a proper factorization system, one can define the composition of relations. The composition is found by first pulling back the cospan and then taking the jointly-monic image of the resulting span
Composition of relations will be associative if the factorization system is appropriately stable. In this case, one can consider a category , with the same objects as , but where morphisms are relations between the objects. The identity relations are the diagonals
A regular category (a category with finite limits and images in which covers are stable under pullback) has a stable regular epi/mono factorization system. The category of relations for a regular category is always an allegory. Anti-involution is defined by turning the source/target of the relation around, and intersections are intersections of subobjects, computed by pullback.
Maps in allegories, and tabulations
A morphism in an allegory is called a map if it is entire and deterministic Another way of saying this is that a map is a morphism that has a right adjoint in when is considered, using the local order structure, as a 2-category. Maps in an allegory are closed under identity and composition. Thus, there is a subcategory of with the same objects but only the maps as morphisms. For a regular category , there is an isomorphism of categories In particular, a morphism in is just an ordinary set function.
In an allegory, a morphism is tabulated by a pair of maps and if and An allegory is called tabular if every morphism has a tabulation. For a regular category , the allegory is always tabular. On the other hand, for any tabular allegory , the category of maps is a locally regular category: it has pullbacks, equalizers, and images that are stable under pullback. This is enough to study relations in , and in this setting,
Unital allegories and regular categories of maps
A unit in an allegory is an object for which the identity is the largest morphism and such that from every other object, there is an entire relation to . An allegory with a unit is called unital. Given a tabular allegory , the category is a regular category (it has a terminal object) if and only if is unital.
More sophisticated kinds of allegory
Additional properties of allegories can be axiomatized. Distributive allegories have a union-like operation that is suitably well-behaved, and division allegories have a generalization of the division operation of relation algebra. Power allegories are distributive division allegories with additional powerset-like structure. The connection between allegories and regular categories can be developed into a connection between power allegories and toposes.
References
Category theory
Mathematical relations | Allegory (mathematics) | [
"Mathematics"
] | 1,067 | [
"Mathematical analysis",
"Mathematical structures",
"Predicate logic",
"Functions and mappings",
"Mathematical objects",
"Basic concepts in set theory",
"Fields of abstract algebra",
"Category theory",
"Mathematical relations"
] |
Subsets and Splits
No community queries yet
The top public SQL queries from the community will appear here once available.