History.

Originally, Pucca was an "animated online e-card service" made in 2000 by the company "VOOZ". The popularity of the e-card increased so rapidly in both Korea and the rest of Asia that it was licensed by Jetix Europe in 2004, who also acquired television rights for the service. VOOZ went on to continue working with Jetix Europe, making the original two and a half minute long animated shorts, which were then aired on both the Jetix website and as in-between full cartoon show shorts on the Jetix television channel. Pucca shorts were also often featured on the channel for MTV. Jetix Europe's director of international licensing, Richard Woolf, stated that "the possibilities with Pucca were immediately apparent, especially because you were left wanting more after watching the original shorts".  More episodes were ordered by Jetix Europe after the success of the initial shorts, with Studio B Productions in charge of making them. The new episodes became more fleshed out to depict Pucca as being a real television series, with more extensive plot being involved and some of the non-speaking characters gaining voices, along with the length of the episodes being extended to seven minutes in total. The new episodes were shown on many of Jetix's worldwide channels.  After the success of the show in television, Jetix began branching out into accessories and toys in order to bring in further revenue from the, now, franchise. These new products included "apparel, accessories, housewares, giftware, and stationery" focused largely on attracting younger teenagers. Since then, the age demographic has expanded to include younger children through the creation of various toy lines and older teenagers through the publishing of video games set in the Pucca universe.

Licensing.

In 2008, Pucca was licensed out to the Access Licensing Group that involved a "merchandising license agreement in North America". This would allow the ALG to begin making Pucca products for sale in the US and it was hoped that Pucca would act as a challenge to the Disney Corporation.  Pucca was also licensed out to Warner Bros. Consumer Products (WBCP) in 2009. Utilizing this, WBCP started a promotional activity on Valentine's Day in France and Italy, where "flowers and Pucca press packs were sent to key journalists." A greater amount of advertising has also been started throughout the regions at various trade shows and there are currently plans to expand this to include shows in Germany and Spain.  Advertising in magazines has also become more prolific through WBCP, with a "full-page Pucca ad...published in Italian Vanity Fair". Despite giving away Pucca toys through Burger King and other efforts, the market for Pucca items has been slow to advance in the UK, but has been placed under a "period of intensive consumer research that will determine the long-term marketing strategy for the brand" both there and in other markets that have been slow to accept the Pucca franchise.

Fashion.

Warner Bros. Consumer Products also exhibited Pucca merchandise during the 2010 New York Fashion Week. Titled the PUCCA Capsule Collection, it was revealed at Curve Boutique on Robertson Boulevard in Los Angeles. A number of Hollywood celebrities were in attendance for the show, along with the founder of Pucca, Boo Kyoung Kim. A number of different designs from various high-profile fashion designers were exhibited at the showing for the PUCCA Capsule Collection.  A new clothing brand, titled "EXR Loves PUCCA", has started in Korea. The Wonder Girls are acting as models for the brand, which will also involve 17 other fashionistas that will be designing the clothing line. The line is a collaboration project between the Pucca franchise and the Korean clothing company EXR.

Animation.

Flash animation.

In the initial period, Pucca was an online animated series made with Macromedia Flash by original company VOOZ Co., Ltd.. Many of its greeting cards and Flash episodes center around Pucca's comical attempts to steal a kiss from Garu and the competition at times between the two characters. There is little to no dialogue in these Flash cartoons so that fans all over the world can enjoy them. In March 2004, Jetix Europe acquired the series' television and home video rights for Europe and the Middle East.

Books.

German translations.

There is also an ongoing manhwa series in Korea of Pucca and Garu traveling around the world through an enchanted board game. Their fellow travelers include friends Abyo, Ching, Ssoso, and villains Tobe and the Vagabond Ninja Clan. It has been translated into Chinese, Spanish, and German.

Video games.

There is a WiiWare game called "Pucca's Kisses Game", which is an action-platformer about Pucca trying to chase Garu around perilous levels and obstacles just to catch Garu and kiss him. This game was developed by Otaboo, and was published by BigBen Interactive. "Pucca's Kisses Game" was released in Europe and Australia on February 4, 2011, and in North America on February 14, 2011 for 800 Wii Points. On February 14, 2011, the game was re-released in Europe as a retail disc entitled "Pucca's Race for Kisses" for the Wii console.  Another game, developed for iOS, called "Pucca n' Friends", was developed by Mob Crete. The game lets players play as Pucca as she prepares food and serves it to her customers, growing her restaurant as the game continues.  The game title, "Pucca Power Up", was announced by Rising Star Games was released on May 13, 2011 for the Nintendo DS. The game is being made with a partnership between the pre-mentioned game company and the franchise's creator, "Vooz". It is set for a release in the UK and, likely, in Australia, but no general European release was initially announced. Later, Rising Star Games announced that the release would be for the entire PAL region, with the game arriving in the UK first. The game was released in Europe on May 13, 2011 and in North America on September 13, 2011.

Pucca (; ) is a media franchise from the South Korean company VOOZ Character System. The main and title character, Pucca, is the niece of three Korean noodle house owners. The noodle house, known as the "Goh-Rong", is located in Sooga Village, a small village in the mountains. Pucca is also in love with the ninja Garu (가루 ), who is mostly shy to share his feelings back to her. Pucca always seems to beat him in combat and unintentional competition simply by sheer will.

Pucca(中国娃娃)是一部由韩国Vooz公司授权于美国华特迪士尼公司制作的动画。故事描述Suga村巨龙饭店的经营者Pucca(布卡,也俗称炸酱面娃娃)对一名忍者男孩Garu(加鲁)陷入热恋,并借着恐怖的怪力在不经意中成功掳获Garu的故事。


Syntax and semantics.

ALGOL W's syntax is built on a subset of the EBCDIC character set. In ALGOL 60 reserved words are distinct lexical items, but in ALGOL W they are merely sequences of characters, and do not need to be stropped. Reserved words and identifiers are separated by spaces. In these ways ALGOL W's syntax resembles that of Pascal and later languages.  The "Algol W Language Description" defines Algol W in an affix grammar that resembles BNF. This grammar was a precursor of the Van Wijngaarden grammar.  Much of Algol W's semantics is defined grammatically:

Example.

This demonstrates ALGOL W's record type facility. RECORD PERSON (  REFERENCE(PERSON) PROCEDURE YOUNGESTUNCLE (REFERENCE(PERSON) R);

Implementation.

The major part of ALGOL W, amounting to approximately 2700 cards, was written in Wirth's PL360. An interface module for the IBM operating system in use (OS, DOS, MTS, ORVYL) was written in IBM assembler, amounting to fewer than 250 cards.  In an OS environment on a 360/67 with spooled input and output files, the compiler will recompile itself in about 25 seconds. The compiler is approximately 2700 card images. Thus, when the OS scheduler time is subtracted from the execution time given above, it is seen that the compiler runs at a speed in excess of 100 cards per second (for dense code).  In a DOS environment on a 360/30, the compiler is limited only by the speed of the card reader. The compiler has successfully recompiled itself on a 64K 360/30 at a rate of 1200 cards per minute (the speed of the card reader). This is impressive when compared to the time required for the DOS Assembler to assemble the interface module which consists of under 250 cards. When the macro instructions are expanded, the DOS interface has 972 card images and the Assembler takes 15 minutes for the assembly.

ALGOL W is a programming language. It is based on a proposal for ALGOL X by Niklaus Wirth and Tony Hoare as a successor to ALGOL 60 in International Federation for Information Processing (IFIP) IFIP Working Group 2.1. When the committee decided that the proposal was not a sufficient advance over ALGOL 60, the proposal was published as "A contribution to the development of ALGOL". After making small modifications to the language Wirth supervised a high quality implementation for the IBM/360 at Stanford University that was widely distributed.

ALGOL W,一种程序语言,为ALGOL家族的一分子。它基于尼克劳斯·维尔特与东尼·霍尔在IFIP Working Group 2.1提出的 草案而设计,希望能作为ALGOL 60的后继者。经过小幅度的修改,在斯坦福大学,尼克劳斯·维尔特利用IBM/360机器,实作出第一版的ALGOL W


Construction.

A truncated octahedron is constructed from a regular octahedron with side length 3"a" by the removal of six right square pyramids, one from each point. These pyramids have both base side length ("a") and lateral side length ("e") of "a", to form equilateral triangles. The base area is then "a". Note that this shape is exactly similar to half an octahedron or Johnson solid J.  From the properties of square pyramids, we can now find the slant height, "s", and the height, "h", of the pyramid:  The volume, "V", of the pyramid is given by:  Because six pyramids are removed by truncation, there is a total lost volume of "a".

Orthogonal projections.

The "truncated octahedron" has five special orthogonal projections, centered, on a vertex, on two types of edges, and two types of faces: Hexagon, and square. The last two correspond to the B and A Coxeter planes.

Spherical tiling.

The truncated octahedron can also be represented as a spherical tiling, and projected onto the plane via a stereographic projection. This projection is conformal, preserving angles but not areas or lengths. Straight lines on the sphere are projected as circular arcs on the plane.

Coordinates.

All permutations of (0, ±1, ±2) are Cartesian coordinates of the vertices of a truncated octahedron of edge length a = √ 2 centered at the origin. The vertices are thus also the corners of 12 rectangles whose long edges are parallel to the coordinate axes.  The edge vectors have Cartesian coordinates and permutations of these. The face normals (normalized cross products of edges that share a common vertex) of the 6 square faces are, and. The face normals of the 8 hexagonal faces are. The dot product between pairs of two face normals is the cosine of the dihedral angle between adjacent faces, either − or −. The dihedral angle is approximately 1.910633 radians (109.471° ) at edges shared by two hexagons or 2.186276 radians (125.263° ) at edges shared by a hexagon and a square.

Dissection.

The truncated octahedron can be dissected into a central octahedron, surrounded by 8 triangular cupola on each face, and 6 square pyramids above the vertices.  Removing the central octahedron and 2 or 4 triangular cupola creates two Stewart toroids, with dihedral and tetrahedral symmetry:

Permutohedron.

The truncated octahedron can also be represented by even more symmetric coordinates in four dimensions: all permutations of (1, 2, 3, 4) form the vertices of a truncated octahedron in the three-dimensional subspace. Therefore, the truncated octahedron is the permutohedron of order 4: each vertex corresponds to a permutation of (1, 2, 3, 4) and each edge represents a single pairwise swap of two elements.

Area and volume.

The area "A" and the volume "V" of a truncated octahedron of edge length "a" are:

Uniform colorings.

There are two uniform colorings, with tetrahedral symmetry and octahedral symmetry, and two 2-uniform coloring with dihedral symmetry as a "truncated triangular antiprism". The construcational names are given for each. Their Conway polyhedron notation is given in parentheses.

Chemistry.

The "truncated octahedron" exists in the structure of the faujasite crystals.

Data Hiding.

The "truncated octahedron" (in fact, the generalized truncated octahedron) appears in the error analysis of quantization index modulation (QIM) in conjunction with repetition coding.

Related polyhedra.

The truncated octahedron is one of a family of uniform polyhedra related to the cube and regular octahedron.  It also exists as the omnitruncate of the tetrahedron family:

Symmetry mutations.

This polyhedron is a member of a sequence of uniform patterns with vertex figure (4.6.2"p") and Coxeter–Dynkin diagram. For "p" < 6, the members of the sequence are omnitruncated polyhedra (zonohedra), shown below as spherical tilings. For "p" > 6, they are tilings of the hyperbolic plane, starting with the truncated triheptagonal tiling.  The truncated octahedron is topologically related as a part of sequence of uniform polyhedra and tilings with vertex figures "n".6.6, extending into the hyperbolic plane: The truncated octahedron is topologically related as a part of sequence of uniform polyhedra and tilings with vertex figures 4.2"n".2"n", extending into the hyperbolic plane:

Related polytopes.

The "truncated octahedron" (bitruncated cube), is first in a sequence of bitruncated hypercubes:

Tessellations.

The truncated octahedron exists in three different convex uniform honeycombs (space-filling tessellations): The cell-transitive bitruncated cubic honeycomb can also be seen as the Voronoi tessellation of the body-centered cubic lattice. The truncated octahedron is one of five three-dimensional primary parallelohedra.

Truncated octahedral graph.

In the mathematical field of graph theory, a truncated octahedral graph is the graph of vertices and edges of the truncated octahedron, one of the Archimedean solids. It has 24 vertices and 36 edges, and is a cubic Archimedean graph. It has book thickness 3 and queue number 2.  As a Hamiltonian cubic graph, it can be represented by LCF notation in multiple ways: [3, −7, 7, −3], [5, −11, 11, 7, 5, −5, −7, −11, 11, −5, −7, 7], and [−11, 5, −3, −7, −9, 3, −5, 5, −3, 9, 7, 3, −5, 11, −3, 7, 5, −7, −9, 9, 7, −5, −7, 3].

In geometry, the truncated octahedron is an Archimedean solid. It has 14 faces (8 regular hexagonal and 6 square), 36 edges, and 24 vertices. Since each of its faces has point symmetry the truncated octahedron is a zonohedron. It is also the Goldberg polyhedron G(1,1), containing square and hexagonal faces. Like the cube, it can tessellate (or "pack") 3-dimensional space, as a permutohedron.

科德尔·赫尔(英语:Cordell Hull,1871年-10月2日-1955年-7月23日),又称贺可德,美国政治家,第47任美国国务卿,1945年获诺贝尔和平奖。


History.

The town of Zhenhai grew up at the foot of Zhaobao Hill on a tongue of land at the mouth of the Yong River about north-east of central Ningbo.  Under the Qing, the city walls covered a circuit of and rose to. The British captured Zhenhai on 10 October 1841 during the First Opium War, dismantling its former citadel. The Zhenhai Coastal Battery was the site of the 1885 Battle of Zhenhai during the Sino-French War.  In the later 19th century, Zhenhai was protected from the sea by a dike about long, made of large blocks of hewn granite.  Zhenhai has suffered severe long-term air pollution mainly emanating from the Ningbo Petro-Chemical Economic and Technical Development Zone built on its eastern coast. The zone is home to nearly 200 chemical plants including Zhenhai Refining and Chemical Corporation (ZRCC), a subsidiary of Sinopec and the largest oil refinery in China, LG-Yongxing, the largest ABS plastic producer in China and Zhenhai Port Liquid Chemical Dock, the largest liquid chemical dock in China. In September, 2007, 400 tones of acrylonitrile leaked from the LG-Yongxing plant and polluted air and underground water around adjacent areas. In late April, 2012, three million bees died in an orchard in Xiepu Town next to the Petro-Chemical Zone because of pollutants discharged by a chemical plant. Research has shown that the ratio of deaths from cancer in Zhenhai rose significantly between 2007 and 2009.  From May16 to 17, 2002, residents in Zhenhai launched protests against environmental degradation caused by the chemical industry, blocking the district's traffic on its main streets. In October, 2012, angry people staged demonstrations against a giant petro-chemical project scheduled by ZRCC and clashed with police. The 50 billion yuan ($8 billion) integrated investment project, according to some reports, will affect more than 9800 households. Many argue that the environment in Zhenhai has been tremendously overloaded and the new project will bring even more harm to the ecosystem.

Administrative divisions.

Subdistricts:  Towns:

Zhenhai is a district and former county of the sub-provincial city of Ningbo in Zhejiang Province in eastern China. It has a population of 200,000.

镇海区,古称蛟川,是中国浙江省宁波市的一个市辖区,为宁波重要的工业区和港区。镇海区位于宁波市域东面,宁绍平原东端,甬江下游,北与慈溪市相邻,南隔甬江与北仑区相望,西与江北区相接,东隔海与舟山市相望,全区陆域面积245.94平方千米,海域面积123.46平方千米。


United States.

In 1851, an article in "The New York Times" referred to the "colored population". In 1863, the War Department established the Bureau of Colored Troops.  The first 12 United States Census counts enumerated '"colored" people, who totaled nine million in 1900. The census counts of 1910–1960 enumerated "negroes". NPR reported that the "use of the phrase "colored people" peaked in books published in 1970." "It's no disgrace to be colored," the black entertainer Bert Williams famously observed early in the century, "but it is awfully inconvenient."  "Colored people lived in three neighborhoods that were clearly demarcated, as if by ropes or turnstiles", wrote Harvard professor Henry Louis Gates, Jr. about growing up in segregated West Virginia in the 1960s. "Welcome to the Colored Zone, a large stretched banner could have said... Of course, the colored world was not so much a neighborhood as a condition of existence." "For most of my childhood, we couldn't eat in restaurants or sleep in hotels, we couldn't use certain bathrooms or try on clothes in stores", recalls Gates. His mother retaliated by not buying clothes that she was not allowed to try on. He remembered hearing a white man deliberately calling his father by the wrong name: "'He knows my name, boy,' my father said after a long pause. 'He calls all colored people George.'" When Gates's cousin became the first black cheerleader at the local high school, she was not allowed to sit with the team and drink Coke from a glass, but had to stand at the counter drinking from a paper cup. Professor Gates also wrote about his experiences in his 1995 book, "Colored People: A Memoir".  In the 21st century, "colored" is generally regarded as an offensive term, due to the fact that signs under Jim Crow depicted the term "colored". The term lives on in the name of the National Association for the Advancement of Colored People, generally called the NAACP. In 2008, its communications director Carla Sims said "the term 'colored' is not derogatory, [the NAACP] chose the word 'colored' because it was the most positive description commonly used [in 1909, when the association was founded]. It's outdated and antiquated but not offensive."

Colored, or coloured, is an ethnic descriptor historically used in the United States (predominantly during the Jim Crow era) and the United Kingdom with its former colonies. In the United States and elsewhere, it is now considered a racial pejorative. Historically, the term denoted non-"white" individuals generally. In contemporary English today, the term "people of colour" has become widespread and is considered more acceptable than coloured and is much more frequently used in everyday conversation.

有色人种 (英语:Colored)是美国或加拿大的曾用词汇,始于北美的殖民时代,指来自撒哈拉沙漠以南非洲的非裔美国人和美洲原住民。现在这个词汇被视为带有种族歧视色彩,不再是政治正确的词汇。但这一词汇在英国的使用,在指带有亚洲、中东或非洲血统的人时,虽然并不常用,但通常并不认为含有贬损意义。这一词汇在南非、纳米比亚、赞比亚和津巴布韦这些地区的使用,特指一族黑白混血的人群。


Biography.

Early life and education.

David Olive was born in Middlesex in 1937 and educated at the Royal High School, Edinburgh and Edinburgh University. He then moved to St John's College, Cambridge, obtaining his PhD under the supervision of John Taylor in 1963.

Career.

After a short postdoctoral appointment at the Carnegie Institute in Pittsburgh, Olive returned to Cambridge as a Fellow of Churchill College, becoming a Lecturer in the Department of Applied Mathematics and Theoretical Physics (DAMTP) in 1965. Here he made key contributions to the approach to particle physics known as S-matrix theory. His 1966 book "The Analytic S-matrix" co-authored with Richard Eden, Peter Landshoff and John Polkinghorne, remains a definitive text on the subject and is known as "ELOP".  In 1971, Olive made what he has described as a "momentous personal decision" to sacrifice his tenured position in Cambridge and move to the Theory Division, CERN as a fixed-term staff member. He was part of a team assembled by to work on the theory originally known as the dual resonance model but shortly to be recognised as string theory. In CERN, Olive began the collaborations with the circle of string theorists many of whom feature in his memoir "From Dual Fermion to Superstring". His work at CERN, in part in collaboration with Lars Brink and Ed Corrigan, initially focused on the consistent formulation of dual fermion amplitudes, generalising the existing bosonic models. This period saw several of Olive's major contributions to string theory, including the Gliozzi-Scherk-Olive (GSO) projection which elucidated the role of spacetime supersymmetry in ensuring consistency of the dual fermion model and was to prove an essential step in establishing 10-dimensional superstring theory. He was one of the first to become convinced of the conceptual revolution whereby string theory is viewed as a unified theory of all particle interactions, including gravity, rather than simply as a model of hadrons. This was the subject of his plenary talk at the 1974 Rochester conference in London.  In 1977, Olive returned to the UK to take up a lectureship at Imperial College, becoming Professor in 1984 and Head of the Theoretical Physics Group in 1988. He had by now begun collaboration with Peter Goddard and together they produced a series of papers on the mathematical foundations of string theory, notably on Virasoro and Kac-Moody algebras and their representations and relation to vertex operators. One outcome of their work on algebras and lattices was the identification of the special role played by the two Lie groups SO(32) and E8 x E8, which would shortly be shown by Michael Green and John Schwarz to exhibit anomaly cancellation that led to the renaissance of string theory in 1984.  This body of work from 1973 to 1983 was recognised with the award of the prestigious Dirac Medal in 1997 to Goddard and Olive "in recognition of their far-sighted and highly influential contributions to theoretical physics. They have contributed many crucial insights that shaped our emerging understanding of string theory and have also had a far-reaching impact on our understanding of 4-dimensional field theory.” The Dirac Medal also recognised a second major line of research pioneered by Olive, on duality symmetries in gauge field theories, this work was to play a key role in later developments of M-theory. While still at CERN, Olive had begun to study the magnetic monopoles which 't Hooft and Polyakov had shown existed in non-abelian gauge theories, publishing a paper with Peter Goddard and Jean Nuyts. In 1977, together with Claus Montonen, he made the remarkable conjecture that there should exist an electromagnetic dual theory in which the roles of monopoles and gauge bosons are interchanged. In subsequent work with Ed Witten, Olive showed that this duality is realised in a certain class of supersymmetric theories. This Montonen-Olive duality was later found to emerge from a deeper web of dualities underlying M-theory, ushering in the of the mid 1990s.  In 1992, Olive left Imperial to take up a research professorship in mathematics and physics at Swansea University, where together with Ian Halliday he built the theoretical particle physics group. He continued to work on mathematical physics, exploring the deep symmetries underlying quantum field theories, especially affine Toda theory. His retirement was marked by a conference "Strings, Gauge Fields and Duality" held in his honour in Swansea in 2004. He presented the Dirac Lecture at DAMTP on 14 June 2004 titled "The Eternal Magnetic Monopole".

David Ian Olive ( ; 16 April 1937 – 7 November 2012) was a British theoretical physicist. Olive made fundamental contributions to string theory and duality theory, he is particularly known for his work on the GSO projection and Montonen–Olive duality.

大卫·伊恩·奥利夫 (英语:David Ian Olive,,1937年-4月16日-archivedate=2013年12月31日|2012年|11月7日|Olive, David}}),英国理论物理学家,对弦理论和对偶理论做出了基础性的贡献。


Signs and symptoms.

Typically, all baby teeth will be present by the age of three. As for all adult teeth, they erupt between the ages 6 to 14, with the exception of the third molar, also known as the wisdom teeth which normally erupt between 17 to 25 years of age. If the tooth has yet to erupt by an appropriate age, panoramic x-rays are taken.

Dental features.

Microdontia may be present in one or more of the other teeth. This means that the teeth appear smaller than normal, may be observed in both the primary and permanent dentition. This condition can be genetically-linked and in severe cases, may present themselves in the form of ectodermal dysplasia, cleft lip or palate or Down Syndrome. A delay in tooth development may also serve as an indication, whereby the absence of an adult successor slows down the normal resorption of the roots of the baby teeth, which is the progressive loss of parts of the tooth.  Misplaced (ectopic) positioning of the adult teeth may be discovered upon examination or a radiograph. One of the consequences may be an adult tooth intercepting with a baby tooth, causing premature loss or wrong positioning. This can be due to either the absence of neighboring teeth acting as a guide during eruption or the lack of space in the jaw for them to erupt into because of malocclusion.

Skeletal features.

Several studies have discovered that anteriorly missing teeth can accompany retrognathic maxilla, also known as an underbite, prognathic mandible, where the lower jaw protrudes out more than normal, and smaller posterior cranial base length. Occurrence of hypodontia can be associated with reduced anterior lower facial height and lip protrusion. This can be linked to lower maxillary to mandibular plane angles.  A more acute mandibular angle and flatter chin may develop as a result. These characteristics become more prominent as the condition becomes progressively severe, particularly when more than one tooth is missing.

Other dental and radiographic features.

Data derived from principal component analysis of radiographic images show that children with mild hypodontia may display the following features- significant increase of the interincisal angle and decrease in the maxillary and mandibular incisor angles.  Cephalometric tracing is commonly used to study a patient’s dentofacial proportions in the craniofacial complex. This can aid in predicting growth changes, allowing dentists, especially orthodontists, to develop a suitable treatment plan. Coupled with that, findings consistent among individuals include: 1) anterior hypodontia associated with hyper divergent craniofacial pattern, 2) a tendency toward a class III malocclusion identified in maxillary hypodontia and 3) reduced lower posterior facial height in children with posterior and mandibular hypodontia.

Associated anomalies.

1. Reduction in coronal or radical dimensions  2. Retained primary teeth  3. Ectopic canine eruption  4. Abnormal morphology such as peg-shaped maxillary lateral incisors and taurodontism, characterized by an enlarged tooth body and roots that are reduced in size.

Cause.

Several theories regarding the aetiology of hypodontia have been proposed in existing literature. There have been various theories mostly looking into genetic and environmental aspects and how they may both be involved. However, the exact cause remains unclear. The extent of individual influences of genetic and environmental factors is still widely debated.  These theories can be categories into "evolutional" or "anatomical".  Preliminary studies focused on an "evolutionary" approach which suggested shortening of the intermaxillary complex and thus shorter arches may contribute to a decrease in number of teeth. This was also suggested in 1945 by Dahlberg using Butler's Field Theory that focused on evolution and development of mammalian teeth into human dentition in an attempt to analyse different of agenesis. In each jaw, four morphological sites were identified (incisors, canines, premolars and molars). The tooth at the end of each region was less genetically stable and hence more prone to absence. In contrast, the tooth most mesial in each region seemed to be more genetically stable. A subsequent theory hypothesised the teeth at the end of each region were possibly “vestigial bodies” that became obsolete during the evolutionary process. At present, it has been theorised that evolutionary change is working to decrease the human dentition by the loss of an incisor, premolar and molar in each quadrant. According to Vastardis (2000), the size of jaws and number of teeth seem to decrease along with human evolution.  Theories focusing on "anatomical" principle, hypothesised that specific areas of the dental lamina are especially prone to environmental effects during tooth maturation. Svinhufvud et al. (1988) suggested that teeth that were more prone to absence developed in areas of initial fusion of the jaw. For instance, maxillary lateral incisors originate where the lateral maxillae and medial nasal bone processes fuse. In contrast, Kjaer et al. (1994) suggested regions where innervation developed were more sensitive than areas of fusion. Commonly affected regions were found to undergo innervation last, this might imply the developmental relationship between nerve and hard tissue. It is thought to be local nerve development that affects tooth agenesis rather than global development, as brainstem anomalies have not been seen to affect tooth development.  Presently, the role of polygenic and environmental factors on hypodontia is recognised in most theories.

Environmental factors.

Environmental factors can be classified into two main groups, invasive and non-invasive. These factors act additively or independently, ultimately affecting positioning and physical development of the tooth.  Invasive environmental factors potentially affect tooth development and positioning leading to hypodontia and impaction. Examples include jaw fractures, surgical procedures and extraction of the preceding deciduous tooth. Treatment such as irradiation has been shown to have severe effects on developing teeth. In a smaller capacity, chemotherapy was also found to have a similar effect. Thalidomide (N-phthaloylglutamine) was also discovered to have a causative effect on mothers who took the drug during pregnancy, resulting in congenitally missing teeth in their children. A link was found between systemic diseases, endocrine disruption (i.e. idiopathic hypoparathyroidism and pseudohypoparathyroidism). and ectodermal dysplasia. However, a definite etiological relationship has yet to be established. Examples of infections include rubella and candida. Exposure to PCBs (ex.dioxin), allergy and toxic epidermal necrolysis after drug. may also be contributing factors.  In a recent study assessing environmental risk factors for hypodontia, it was established that maternal smoking does play a causative role in hypodontia. Passive smoking and caffeine were also assessed but showed no statistical significance.  The Journal of the American Dental Association published preliminary data suggesting a statistical association between hypodontia of the permanent teeth and epithelial ovarian cancer (EOC). The study shows that women with EOC are 8.1 times more likely to have hypodontia than are women without EOC. The suggestion therefore is that hypodontia can serve as a "marker" for potential risk of EOC in women.

Genetics.

Genetic causes also involve the genes MSX1 and PAX9.  Genetic associations for selective tooth agenesis ("STHAG") include: Failure of tooth formation due to disturbances during the early stages of development could be the cause of congenital missing teeth, this is also known as tooth agenesis. A variety of studies shows that missing teeth are commonly associated with genetic and environmental factors. Some literature also show that a combination of both factors may contribute to the occurrence of missing teeth.  Genetics has always played a crucial role in dental aplasia. The pattern of congenitally missing teeth seen in monozygotic twins is different, suggesting an underlying epigenetic factor, which may be due to the simultaneous occurrence of two anomalies. This multifactorial aetiology involves environmental factor which triggers the genetic anomalies resulting the occurrence of dental agenesis. Common environmental factors include infection, trauma and drugs which predispose to the condition. In hereditary cases, evidence of dental germ developing after surrounding tissues have closed the space required for development may be a huge contributing factor as well such as genetic disorders like down syndrome, ectodermal dysplasia, cleidocranial dysplasia, orofacial clefting, especially cleft lip and palate.  Most the craniofacial characteristics are influenced by the both genetic and environmental factors through complex interactions. The variable expressivity of traits can be either completely genetic determined, environmental determined or both. The multiplicity of hypodontia theories suggest that missing teeth are strongly influenced by genetic factor. Although single gene defect may contribute to the cause of hypodontia, but more studies propose that hypodontia is mainly the result of one or more point of genetic mutations which are closely linked, which is known as polygenic defect.  Despite the aetiology of missing teeth is remained consensus, but genetic plays an important role for hypodontia is shown in many different cases. There are over hundreds genes are expressed and involved in regulating tooth morphogenesis.

MSX1.

MSX1 (muscle segment homeobox 1) involved in condensation of ectomesenchyme in the tooth germ. Among the members of homeobox genes, MSX1 and MSX2 are crucial in mediating direct epithelial-mesenchymal interactions during tooth development by expressing in regions of condensing ectomesenchyme in the tooth germ. MSX1 mutations have been identified as one of the contributing factors of missing second premolars, third molars, with a small percentage of first molars. MSX1 is less likely to cause anterior agenesis.  Heterozygous mutations in PAX9 (paired box gene 9) could arrest tooth morphogenesis as it plays a role of transcription the gene expressed in tooth mesenchyme at the bud stage during tooth development. A study showed that single nucleotide polymorphisms in PAX9 were highly associated with missing upper lateral incisors.

AXIN2.

AXIN2 (AXIS inhibition protein 2) gene is negative regulator of the Wnt signalling pathway, which is important in regulating cell fate, proliferation, differentiation and apoptosis. It's polymorphic variant may be associated with hypodontia such as missing lower incisors or in a more severe form of agenesis like oligontia (lack of six or more permanent teeth).

EDA.

The EDA provides instructions for making a protein called ectodysplasin A. It encodes transmembrane protein that is part of TNF (tumour necrosis factor) family of ligands. EDA gene defects cause ectodermal dysplasia, which is also known as X-linked hypohidrotic ectodermal dysplasia. Common dental features of ectodermal dysplasia are multiple missing teeth and microdontia.  PAX9 and TGFA are involved in regulating between MSX1 and PAX9 causing hypodontia of the molars.  Hypodontia can be found in isolated cases too. The familiar or sporadic type of isolations are more frequently reported than syndromic type. Isolated cases autosomal dominant, autosomal recessive or X-linked inheritance patterns may have an impact on the isolation conditions in expressing variation of both penetration and expressivity of traits. Mutations in MSX, PAX9 and TGFA genes are known to cause congenitally missing teeth in some racial groups.

Research.

In the 1960s and 1970s, several studies were conducted sponsored by the U.S. Atomic Energy Commission, with the aim of finding a link between genetics and hypodontia.

Impacts.

There is numerous studies or research report on the prevalence, aetiology, treatment of hypodontia and dentoskeletal effect of hypodontia. A few studies have investigated Oral Health-related Quality of Life (OHRQoL) in individuals with hypodontia and provided some evidences that hypodotia may have an impact on quality of life.

Psychosocial.

Cosmetic dentistry and facial aesthetic are notable for today's popular culture. Interpersonal relationships and perceived qualities, for instances intelligence, friendliness, social class, and popularity from infancy to adulthood, can be affected by dentofacial appearances. Some studies showed that the extent of complaints made by patients was associated with the severity of the condition and the number of missing permanent teeth.  Meta-analyses and theoretical reviews demonstrated that attractive children are seen by others as more intelligent and exhibit more positive social behaviour and traits other than receiving much more positive treatment than their less attractive counterparts. Therefore, a divergence from perceived ideal dentofacial aesthetic, particularly in children, might adversely affect self-esteem and self-confidence besides attracting mockery from peers.  It is therefore reasonable to theorize that deviations from “normal” or “ideal” dentofacial aesthetic could be destructive to an individual's psychosocial and emotional well-being, which brings upon some psychosocial distress in that individual as a result of his or her condition.

Functional.

Individuals with hypodontia tend to have deeper bites and spaces. Further deepening of the bite can also be seen on individuals with missing posterior teeth. Apart from that, hypodontia may lead to non-working interferences, poor gingival contours and over-eruptions of the opposing teeth.  It has been found that individual with hypodontia experience more difficulty during mastication or functioning movements due to smaller occlusal table available. A recent cross-sectional study showed that hypodontia patients have more difficulties in chewing, especially if the deciduous teeth associated with the missing permanent teeth had been exfoliated. Despite currently limited evidence to support this statement, it is plausible that hypodontia may pose functional limitations, which eventually affect that individual's general well-being and quality of life.  Hypodontia can indeed pose limitations on the chewing ability of a patient. The condition can be associated with split in the upper lips – a condition known as oral cleft. Hypodontia can have impacts on speech, aesthetics and function of muscles in the mouth. As a result, hypodontia can have negative impacts on the quality of life, although the condition can be well managed and treated by dentists and orthodontists. To manage the condition, the patient will need to have long-term orthodontic treatment.

Financial.

Patient with hypodontia requires careful treatment plan due to complex case in order to ensure the best treatment outcomes. Such treatment plans require multi-disciplinary approach, which usually come at a financial cost to both patient and possibly their family. Due to this reason, a team consists of different dental specialties is involved in the patient care.

Management.

Hypodontia is a condition that can present in various ways with differing severities. This results in a wide range of treatment methods available. Those affected should be allowed to consider and select the most suitable option for themselves. Early diagnosis of hypodontia is critical for treatment success. The treatment of hypodontia involves specialists in departments such as oral and maxillofacial surgery, operative dentistry, pediatric dentistry, orthodontics and prosthodontics.  Before determining a treatment plan, the following should be determined:  Traditionally, the management of hypodontia has involved replacing missing teeth. By replacing the missing teeth, it can prevent neighbouring teeth tilting or drifting and also prevents the overeruption of opposing teeth which could then impact on occlusion and temporo-mandibular joint dysfunction and impact the patient’s susceptibility to gum disease, tooth wear and tooth fractures. However, studies have suggested that a stable occlusion can be achieved even with a shortened arch of 10 occluding pairs of teeth. The findings support the concept that a healthy and stable occlusion can exist despite missing teeth as long as an acceptable number of teeth are in occlusion. However, this management technique may not be suitable for those with gum disease, parafunctioning activity (tooth grinding or clenching) or malocclusion.  It should also be noted that spaces within the dental arch should be monitored, especially in younger patients, as teeth are more likely to drift, tilt or over-erupt. To do this, study models and clinical photographs could be taken in order to record baseline records. If tooth movement was to occur, another form of management may be required depending on the severity and nature.  The following below are the methods used to manage hypodontia:

Accept spacing.

This is a method suitable to individuals if the space from a missing tooth is not deemed to be an aesthetic concern. Appearance may not be a problem in some cases, for example, when spacing present behind the canines may not be particularly visible, depending on the individual.

Management of retained primary teeth.

When there is a case of hypodontia of the permanent premolar teeth, the primary molar teeth would often remain in the mouth beyond the time they are meant to be lost. Therefore, with a presence of healthy primary teeth in the absence of a permanent successor, retaining the primary teeth can be a feasible management of hypodontia.  The primary molars present also functions as a space maintainer, prevent alveolar bone resorption and delays future prosthodontic space replacement by acting as a semi permanent solution going into adulthood Previous studies also shown a good prognosis of retained primary molars going into adulthood. However, leaving the primary teeth in place may run the risk of tooth infraocclusion where the occlusal surface is below that of adjacent teeth.  Despite this, the retention of primary teeth, particularly molars, are more susceptible to occlusal wear, over-eruption of opposing teeth and the loss of inter-occlusal space.

Orthodontic space closure.

Orthodontic space closure is a way of using orthodontics in order to close spaces in the mouth where the teeth are missing. The ideal age for definitive orthodontic treatment is early adolescence but it is important to consider the patient’s age, severity of hypodontia, patient expectations and their commitment to treatment. It can be an option for hypodontia management in the case of missing maxillary lateral incisors through the reshaping, and mesial re-positioning of the adjacent canine. This management is indicated in hypodontia cases of Class I molar relationship with severe crowding in the mandibular anterior region where the extraction of lower premolar leads to a predictable outcome, and Class II molar relationship in the absence of crowding and protrusion of the mandibular anterior dentition.  When moving the canine into the space of the lateral incisor, the dimensions of the canine, root position and gingival position differ from a lateral incisor and therefore preparation of the canine is necessary in order for it to mimic the incisor. This may involve:  - Reduction of the incisal tip and addition of composite on the incisal edge to create a straight contour and a rounded disto-incisal corner  - Reduction of the mesial and distal surfaces to reduce the width of the tooth  - Flattening of the labial surface to reduce bulbosity. However, removal of enamel by expose the darker coloured dentine and therefore further restoration may be required.  - Preparation of the palatal surface of the canine to reduce its bulk.  The use of veneers can also be used instead of composite however, these are more expensive and more time consuming.  There have been several studies which showed the advantages of orthodontic space closure without prosthodontic space replacements. The main advantage mentioned is the early completion of the treatment during early adolescence and the long lasting result of the treatment outcome. In individuals with a high smile line, the mesial re-positioning of canine maintains the normal soft tissue architecture is important in maintaining the aesthetic appearance. This option also negates the risks and costs that comes with prosthodontic treatment and the impression that there is no missing tooth.  Some factors need to be considered when making a decision whether to undergo space closure. These include facial profile, size and dimension of canine, the shade of colour of the teeth and the gingival contour and height. Group function occlusion is usually present as a result of the mesial movement of the canine. In order to maintain the stability of the closed space, direct-bonded lingual retainers are usually required.

Orthodontic space opening prior to prosthodontic treatment.

The need for orthodontic space opening prior to prosthodontic management depends on the amount of edentulous space available in relation to adjacent teeth, occlusion and aesthetic concerns. To determine the amount of space needed, three methods in the literature can be used which are the "golden proportion", the "Bolton Analysis" and comparing the edentulous space with the contralateral tooth size if present.  Space opening and prosthodontic treatment is indicated where there is a Class I molar relationships in the absence of malocclusion Class III molar relationships presenting with a concave facial profile. However, the alteration in appearance during orthodontic treatment (e.g. creating diastema for placement of prostheses) before the filling up the space, although temporary, can negatively impact the oral health-related quality of life in adolescents.

Removable partial dentures.

Removable partial dentures are known to be an effective interim method for maintaining functional and aesthetic demands in a growing patient, where definitive fixed restorations are not suitable yet. Removable dentures act as a space maintainer and also prevent the migration of adjacent or opposing teeth, thereby preserving the face height. They are also easy to adjust or add on to in the event of further tooth eruption. However, it may be difficult for young individuals to adhere with wearing removable dentures, due to their bulk. Some patients also find the idea of dentures functionally and socially unacceptable, making them unwilling to comply. Removable prosthetic devices are also known to cause damage to the remaining teeth if worn over a long period of time.

Conventional crown and bridgework.

Fixed restorative options are generally preferred over removable ones.

Tooth autotransplantation.

Autotransplantation involves the removal of a tooth from one socket and relocating to another socket in the same individual. If done successfully, it is able to ensure stable alveolar bone volume as there is continuous stimulation of the periodontal ligament.

Implant supported tooth replacement.

Placing dental implants has proven to be a predictable and reliable method of treating hypodontia, along with bringing excellent aesthetic results. Implant placement should be delayed until jaw growth in an individual is complete. One limitation of implant placement would be the need for a sufficient amount of bone volume, which if not met, may affect the positioning of the implant. However, bone grafting can be carried out to overcome this.

Epidemiology.

Hypodontia is less common in the primary dentition with reported prevalence rates ranging from 0.5% in Icelandic population to 2.4% in Japanese population. In the primary dentition the teeth reported as most likely to be missing are the lateral incisors, both maxillary and mandibular. If a deciduous tooth is missing this will increase the risk of an absent successor.  In the permanent dentition third molars are most commonly absent and one study found prevalence rates of between 20 and 22%. When third molars are ignored the prevalence rate for each tooth varies from study to study. In Caucasian studies mandibular second premolars and maxillary lateral incisors are most often absent. Several UK studies have found the lower second premolar to be most commonly absent. Studies from Asian populations report that the mandibular incisor is most commonly absent.  A higher prevalence of hypodontia in females has been reported, 3:2. The most extensive studies have been in Caucasian populations and suggest a prevalence of 4-6%.  One study looked at 33 previous studies with a sample size of 127000 and concluded that the prevalence of hypodontia in the permanent dentition varied between continents, racial groups and genders. In the white European population they suggested a prevalence of 4.6% in males and 6.3% in females. In an African-American sample they found this to be 3.2% in males and 4.6% in females. The same study found that in the permanent dentition the most likely teeth to be missing and the frequency of these missing teeth was:

Hypodontia is defined as the developmental absence of one or more teeth excluding the third molars. It is one of the most common dental anomalies and has a negative impact on both looks and function. It rarely occurs in primary teeth (also known as deciduous, milk, first and baby teeth) and the most commonly affected are the adult second premolars and the upper lateral incisors. It usually occurs as part of a syndrome that involves other abnormalities and requires multidisciplinary treatment.

缺牙症 (hypodontia)代表病患缺少一定数量的牙齿,特指缺牙数在六颗以内的情形〈不包含智齿〉。在乳牙期阶段,上颚的患病率较下颚高,且多为侧门牙缺乏。


Club career.

Norway.

Nordtveit began his career as a youth in Norway with Vats 94 and Skjold. On 20 August 2006 he became the youngest player ever to play for Haugesund, as he was selected for the starting line-up in a 2–0 victory against Sogndal at Haugesund Stadium. He made nine league appearances during the following season for Haugesund in the Norwegian First Division. That season he also appeared in the Norwegian Football Cup, being in the starting line up in the 1–6 victory against Djerv 1919 (1st round), and coming on in the 33rd minute in a 4–0 victory over Løv-Ham scoring one goal (third round). Haugesund went all the way to the final.

Arsenal.

Arsène Wenger travelled to Norway on 11 June 2007 to watch an Adeccoligaen match and begin negotiations to sign Nordtveit. The members of the FKH board stated that the club had rejected Arsenal's initial bid. The player himself said that his club was asking for a "supernaturally high" transfer fee. The price being quoted in the Norwegian media was 20 million Norwegian kroner (approximately £1.7 million at the time). A transfer fee was later finalized on 3 July 2007 for £500,000 initially, rising to £2m after 40 first team appearances. He was thereafter given the shirt number 55 by the club.  Haugesund captain Kevin Nicol and former Norway coach Nils Johan Semb went on to praise him as the brightest defensive talent in Europe.  He made his Arsenal debut in their first pre-season friendly against Barnet on 14 July 2007. Nordtveit came on after half-time, replacing Kerrea Gilbert. He was named captain of Arsenal's reserve squad for the first match of the 2007–08 FA Premier Reserve League season. In an interview with Arsenal.com, Nordtveit said he was "honoured" to have been named captain, and that he hoped to continue in that role in the future.  In the final game of the 2007–08 season he was named on the substitutes' bench in Arsenal's 1-0 win over Sunderland.

2008–09 season.

On 18 August 2008, Salamanca of the Segunda División signed him on a six-month loan. At Salamanca he played alongside another young Arsenal player, Pedro Botelho. He came off the bench to make his debut for UD Salamanca as they drew 1-1 with Sevilla Atlético in the second fixture of the season.  Arsenal recalled him on 29 October, after becoming unhappy with the amount of playing time the Norwegian had received. However, he was not eligible to play for the club until 1 January 2009. On 21 January, he finally made his first appearance for the reserves since spending time on-loan at UD Salamanca, in a 2–2 draw against the Stoke City reserves.  On 10 March 2009, Norwegian top division outfit Lillestrøm signed Nordtveit on loan until 1 August 2009. He made his debut in the Tippeligaen in Lillestrøm's season opener away against Stabæk as a right fullback. This was a role which he retained during his time with the Norwegian side.

2009–10 season.

On 28 July 2009, 1. FC Nürnberg agreed a one-year loan deal for the Norwegian defender from Arsenal. Despite being a centre-back, his primary role at Nürnberg was in the defensive midfield position.

Borussia Mönchengladbach.

On 30 December 2010, Nordtveit joined Borussia Mönchengladbach on a three-and-a-half-year contract, the transfer fee was £800,000. He made his competitive debut for the club on 15 January 2011 in their Bundesliga match against Nürnberg. Nordtveit scored his first goal in Germany, against 1. FC Köln in a 5–1 victory for Borussia Mönchengladbach. He was used mostly as a defensive midfielder, and established himself as a key player for Gladbach, taking the departed Michael Bradley's place in the squad.

West Ham United.

On 16 May 2016, it was announced that Nordtveit would be joining West Ham United on 1 July 2016 on a five-year contract. He made his official debut for the "Hammers" on 28 July in a 2–1 defeat to NK Domžale in the first leg of a Europa League qualifying match, playing the full 90 minutes.

Hoffenheim.

On 20 June 2017, West Ham announced that Nordtveit had signed for German side 1899 Hoffenheim, for an undisclosed fee.

Fulham.

On 31 January 2019, Nordtveit join Fulham on loan until 30 June 2019.

International career.

Nordtveit was a regular for the Norway U-17 in qualifying and they barely missed out on a place at the 2007 European Championships. After that he was promoted to the U-19 squad and was ever-present during the 2009 European Championship qualifying, scoring twice, but once again Norway did not make it past the elite qualification stage. He has been a regular for the U-21 team in the 2011 European Championship qualifying campaign. He made his first international appearance on 7 June 2011, in a friendly game against Lithuania. Nordtveit scored his first goal for the national team when he scored Norway's first goal in the friendly match against Northern Ireland on 29 February 2012, which Norway won 3–0. Nordtveit later became a regular in the senior squad, but in October 2012 he was suspended from playing the 2014 FIFA World Cup qualification match against Cyprus due to yellow cards. Nordtveit was instead called up for the under-21 side where he played an important role in the 5–3 win against France U21 when Norway qualified for the 2013 UEFA European Under-21 Football Championship.

Honors.

Norway U21

Håvard Nordtveit (born 21 June 1990) is a Norwegian professional footballer who plays as a defensive midfielder for Hoffenheim and the Norway national team.

霍瓦尔·努尔特韦特(,1990年-6月21日),是一名挪威足球运动员,司职后卫,现时被德甲球会贺芬咸外借至英超球队富咸。


Production.

Ethyl acrylate is produced by acid-catalysed esterification of acrylic acid, which in turn is produced by oxidation of propylene. It may also be prepared from acetylene, carbon monoxide and ethanol by a Reppe reaction.

Reactions and uses.

Precursor to polymers and other monomers.

Ethyl acrylate is used in the production of polymers including resins, plastics, rubber, and denture material.  Ethyl acrylate is a reactant for homologous alkyl acrylates (acrylic esters) by transesterification with higher alcohols through acidic or basic catalysis. In that way speciality acrylates are made accessible, e.g. 2-ethylhexyl acrylate (from 2-ethylhexanol) used for pressure-sensitive adhesives, cyclohexyl acrylate (from cyclohexanol) used for automotive clear lacquers, 2-hydroxyethyl acrylate (from ethylene glycol) which is crosslinkable with diisocyanates to form gels used with long-chain acrylates (from C18+ alcohols) as comonomer for comb polymers for reduction of the solidification point of paraffin oils and 2-dimethylaminoethyl acrylate (from dimethylaminoethanol) for the preparation of flocculants for sewage clarification and paper production.  As a reactive monomer, ethyl acrylate is used in homopolymers and copolymers with e.g. ethene, acrylic acid and its salts, amides and esters, methacrylates, acrylonitrile, maleic esters, vinyl acetate, vinyl chloride, vinylidene chloride, styrene, butadiene and unsaturated polyesters. Copolymers of acrylic acid ethyl ester with ethene (EPA/ethylene-ethyl acrylate copolymers) are suitable as adhesives and polymer additives, just like ethene vinyl acetate copolymers. Copolymers with acrylic acid increase the cleaning effect of liquid detergents, copolymers with methacrylic acid are used as gastric juices tablet covers (Eudragit®).  The large number of possible comonomer units and their combination in copolymers and terpolymers with ethyl acrylate allows the realization of different properties of the acrylate copolymers in a variety of applications in paints and adhesives, paper, textile and leather auxiliaries together with cosmetic and pharmaceutical products.  Owing to its tendency to polymerize, samples typically contain an inhibitor such as hydroquinone.

As Michael acceptor and HX acceptor.

Ethyl acrylate reacts with amines catalyzed by Lewis acids in a Michael addition to β-alanine derivatives in high yields:  The nucleophilic addition at ethyl acrylate as an α,β-unsaturated carbonyl compound is a frequent strategy in the synthesis of pharmaceutical intermediates. Examples are the hypnotic glutethimide or the vasodilator vincamin (obsolete by now) or more recent therapeutics such as the COPD agent cilomilast or the nootropic leteprinim.  Ethyl 3-bromopropionate is prepared by hydrobromination of ethyl acrylate.

Dienophile.

With dienes, ethyl acrylate reacts as a good dienophile in Diels–Alder reactions e.g. with buta-1,3-diene in a [4+2] cycloaddition reaction to give a cyclohexene carboxylic acid ester in a high yield.

Natural occurrence.

Ethyl acrylate is also used as a flavoring agent. It has been found as a volatile component in pineapples and Beaufort cheese and is a secondary component in vanilla flavor obtained from heat extraction of vanilla in amounts of up to 1 ppm. In such high concentrations it negatively affects the extracted aroma.

Safety.

The International Agency for Research on Cancer stated, "Overall evaluation, ethyl acrylate is possibly carcinogenic to humans (Group 2B)." The United States Environmental Protection Agency (EPA) states, "Human studies on occupational exposure to ethyl acrylate... have suggested a relationship between exposure to the chemical(s) and colorectal cancer, but the evidence is conflicting and inconclusive. In a study by the National Toxicology Program (NTP), increased incidences of squamous cell papillomas and carcinomas of the forestomach were observed in rats and mice exposed via gavage (experimentally placing the chemical in the stomach). However, the NTP recently determined that these data were not relevant to human carcinogenicity since humans do not have a forestomach, and removed ethyl acrylate from its list of carcinogens." (Occupational exposure generally involves exposure that occurs regularly, over an extended period of time.)  It is toxic in large doses, with an LD50 (rats, oral) of 1020 mg/kg, and day to day continuous exposure to 5 ppm is considered safe. As of October 2018, the FDA withdrew authorization for its use as a synthetic flavoring substance in food, without regard to its continuing stance that this substance does not pose a risk to public health under the conditions of its intended use.  One favorable safety aspect is that ethyl acrylate has good warning properties; the odor threshold is much lower than any level of health concern. In other words, the bad odor warns people of ethyl acrylate's presence long before the concentration reaches a level capable of creating a serious health risk. Reports of the exact levels vary somewhat, but, for example, the U.S. E.P.A. reports an odor threshold of 0.0012 parts per million (ppm), but the E.P.A.'s lowest level of health concern, the Acute Exposure Guideline Level-1 (AEGL-1) is 8.3 ppm, which is almost 7000 times the odor threshold.

Ethyl acrylate is an organic compound with the formula CHCHCOCHCH. It is the ethyl ester of acrylic acid. It is a colourless liquid with a characteristic acrid odor. It is mainly produced for paints, textiles, and non-woven fibers. It is also a reagent in the synthesis of various pharmaceutical intermediates.

丙烯酸乙酯(Ethyl acrylate)是一种有机不饱和乙基酯单体,易发生聚合,可用来生产多种聚合物。其蒸气在远低于有害浓度之下即有明显刺激性气味。


History.

The importance of civilian manufacturing and support services in a nation's capacity to fight a war first became apparent during the twenty-five years of the French Revolutionary and Napoleonic wars when the United Kingdom was able to finance and, to a lesser extent, arm and supply the various coalitions which opposed France. Although Britain had a much smaller population than France, its global maritime trade and its early industrialisation meant that its economy was much larger than that of France, which allowed Britain to offset the French manpower advantage.  Durin the American Civil War, the capacity of Northern factories and agriculture proved as decisive in winning the war as the skills of the generals of either side.

World War I.

During World War I, the British Shell Crisis of 1915 and the appointment of David Lloyd George as Minister of Munitions was a recognition that the whole economy would have to be geared for war if the Allies were to prevail on the Western Front. The United States home front during World War I saw the first ring World War II.

World War II.

A factor in Allied victory in World War II was the ability of Allied nations to successfully and efficiently mobilize their civilian industries and domestic populations in order to turn out weapons and goods necessary for waging war. By contrast, mobilization of economic resources in Nazi Germany was so inefficient that some early historians of the Reich's economy concluded that the Nazi leadership must have had an intentional policy of favoring civilian over military production until late in the war. The British, by contrast, had already accomplished mobilization for total war by 1940, thereby increasing the output of weapons—especially heavy bombers—vastly. This view was for example presented quite early by John Kenneth Galbraith in "Fortune" magazine in 1945 "The simple fact is that Germany should have never lost the war...". According to Adam Tooze this view was influenced by the post-war reports from Albert Speer and SS "Wirtschaftsführer" (economy leader), which were not free from own interests. Tooze's alternative view is that Germany was extremely mobilising - already in 1939 there was a higher degree of mobilisation of women in Germany, for example, than Britain ever achieved during the whole war -, but the economy of Germany was simply not strong enough in comparison to the economies of the war opponents, especially with respect to the ever growing support coming from the USA. Slave labour and foreign labour in addition to women's labour could not change this. Hitler was early aware of this German weakness. He hoped, however, by a series of Blitzkriegs to change the situation early enough in favour of Germany. This failed due to military defeats in Russia and the ongoing support provided by the US to Britain.  During the Nazi invasion of the Soviet Union, Soviet soldiers and civilians moved their industries out of reach of the advancing Germans (sometimes disassembling and reassembling entire factories) and began turning out vast numbers of T-34 tanks, Il-2 attack aircraft, and other weapons.

Home front is an English language term with analogues in other languages. It is commonly used to describe the full participation of the British public in World War I who suffered Zeppelin raids and endured food rations as part of what came to be called the "Home Front".

大后方是泛指交战双方战线后方的非正式用语,简单来说就是两军的基地。大后方作用为为前线提供军需品、生活补给、较前线更高的医疗水准,及物资装备的制造、生产和研发等等。闪击战的基础理论之一就是通过切断敌军前线部队与大后方的联系与补给,削弱敌军出租车气及战斗力。


Construction.

"Nerpa" was laid down at the Komsomolsk-on-Amur shipyard in 1993, but its completion was delayed for nearly a decade due to a lack of funds caused by the economic crisis of the early 1990s. The partly constructed vessel was mothballed until 2004, when Rosprom (the Federal Agency for Industry) signed an agreement with the Indian government to complete the submarine and lease it to the Indian Navy. The vessel was intended to be completed by 2007, but underwent further delays. In 2007, it was transferred to the Vostok shipyard in the closed city of Bolshoy Kamen, Primorsky Krai, for fitting-out. It was launched in October 2008 for sea trials, following which it was due to be handed over to the Russian Defence Ministry. Reports in the Indian media suggest that the resumption of construction was underwritten with Indian funding.  The standards of the vessel's construction were criticised by several commentators. Aleksandr Golts, defence editor of the "Yezhednevny Zhurnal" newspaper, said that in the 1980s, the Amur shipyard turned out submarines "one after another, like pancakes," but from 1993 to 2008 had produced just one. "The old specialists had left, and the new ones lacked professionalism." An unnamed worker at the Amur shipyard told "Komsomolskaya Pravda" that there were "questions about the quality of the metal that was used in building the nuclear submarine", some of which had been bought from China, and alleged that "when the first trials of the submarine were carried out water was leaking in between the seams! So it is not surprising that the work dragged on."  During May 2009, the repairs were reported to be almost complete and new sea trials were planned for 15–20 June. By October 2009, the work had still not been completed due to the shipyard's electrical supply having been disconnected. Nikolay Povzyk, the head of the shipyard, complained they had not been paid the 1.9 billion roubles (63.8 million dollars) owed for the work carried out on "Nerpa".

Lease to India.

As of 2008, Russia had an agreement pending with India worth US$2 billion for the lease of "Nerpa" and another Project 971 Shchuka-B-class submarine. Of this, "K-152 Nerpa" will be leased for 10 years to India at an estimated cost of US$670 million. The submarine was handed over to India on 30 December 2011. After being handed over to the Indian Navy, it was commissioned as INS "Chakra". "Nerpa" is the Russian word for the Baikal seal, and "Chakra" is the mythical weapon of the Hindu god Vishnu.  Indian naval crews earlier trained to operate the submarine near St Petersburg and another group of sailors was expected to arrive in Vladivostok in late 2008 for sea trials. The training of the crew was viewed as crucial to India's own nuclear submarine programme, known as the Arihant class submarine.  After the 2008 accident, there were conflicting reports over the status of the lease. A Russian defence industry official denied that talks had been held with India on the delivery of the nuclear submarine. "Russia did not launch talks on a contract to supply India with the Nerpa nuclear-powered submarine." General of the Army Nikolay Makarov stated that Russia would commission "Nerpa" and that it would join seven other with Russia's Pacific Fleet. "The sum of $650–780 million, which Rosoboronexport and the Amur Shipbuilding Plant had negotiated over a long period of time with the Indian Ministry of Defence, will now be found in Russia," he said.  In May 2009, both Russian and Indian defence officials confirmed that "Nerpa" would be joining the Indian Navy by the end of 2009, after Russian President Vladimir Putin visited the yard and announced an immediate release of 1.2 billion roubles for the submarine's construction.  On 28 December 2009, "Nerpa" was commissioned and joined the Russian Navy. The submarine underwent further adjustments in February 2010. By August 2010, Russia was training a crew from the Indian Navy to sail the boat to India in fulfilment of the lease agreement. INS "Chakra" was expected to be commissioned into the Indian Navy before October 2011. On 1 July 2011, Russian Navy chief Admiral Vladimir Vysotsky has been quoted as holding that "the Indian crew is now absolutely prepared for operating the submarine", which will be on a 10-year lease."  On 23 January 2012, the ship was commissioned at Bolshoy Kamen under the command of Captain P Ashokan. She commenced her home voyage under Indian control from the Russian port of Vladivostok to its Indian base Visakhapatnam. Official Russian announcement of the transfer was still pending at that time. INS "Chakra" was inducted into the Indian Navy on 4 April 2012.  The similarly named "Chakra" was a Charlie I-class submarine leased by India from Russia 1988–1992.

2008 accident.

An accident occurred aboard "K-152 Nerpa" at 8:30 PM local time on 8 November 2008, during an underwater test run in the Pacific Ocean. A total of 208 people – 81 military personnel and 127 civilians – were on board at the time of the accident. At least 20 people were killed by asphyxiation and at least 21 more were injured, making it the worst Russian submarine disaster since "Kursk" sank in 2000. Three of the dead were military personnel and the rest were civilians from the Vostok, Zvezda, Era and Amur shipbuilding yards who were members of the acceptance team.  The incident involved the accidental triggering of a fire extinguishing system which sealed two forward compartments and released Halon 2402 (freon R-114B2), dibromotetrafluoroethane gas into them. According to survivors, those affected by the gas release were caught off guard and may not have been alerted in time due to warning sirens sounding only after the gas had already begun pouring in. Some of the victims were reported to have been unable to turn on breathing kits before they suffocated.  On 10 November, a Russian Navy statement blamed the disaster on an "unsanctioned operation" of the fire suppression system aboard "Nerpa". Preliminary investigations concluded that the system had triggered automatically without human intervention. On 13 November, naval investigators announced that a crewman had turned on the system "without permission or any particular grounds".

2017 accident.

Indian media aired public reports in early October 2017 that indicated that INS "Chakra" had suffered damage while entering Visakhapatnam harbor, including a large hole in the sonar dome in the bow. A Russian team visited India for a joint investigation, which led to the submarine being dry docked for repairs at a cost of ₹125 crore ($20 million) to fix the damage.

2019.

Post 2019 Balakot airstrike conducted by Indian Air Force, Indian Navy deployed INS Chakra along with INS "Kalvari" (S21) to search for the Pakistani submarine PNS Saad which was believed to be deployed.

INS "Chakra" is a Project 971 (or Project 518; NATO: ) nuclear-powered attack submarine. The construction of the Nerpa submarine was started in 1993, but was then suspended due to lack of funding. The Indian Navy sponsored the building and sea trials of the submarine provided it was given to the Indian Navy on lease for 10 years. It was launched as "K-152 Nerpa" in October 2008 and entered service with the Russian Navy in late 2009. The submarine was leased to the Indian Navy in 2011 after extensive trials, and was formally commissioned into service as INS "Chakra" II at a ceremony in Visakhapatnam on 4 April 2012. The INS "Chakra" joined the Eastern Naval Command at Visakhapatnam.

海豹号为一艘俄罗斯海军阿库拉级核潜艇,型号为阿库拉III型,舷号为K-152。


History.

The original 'Government Hut' was a thatched hut constructed by the seamen of HMS "Buffalo". Governor John Hindmarsh wrote in May 1837 "I have but one end of my mud hut finished an all my family lay on the floor of one room while two smaller ones serve for Mrs. H., myself and a female servant." When Lieutenant Colonel George Gawler replaced Hindmarsh in 1838, he abandoned plans for a permanent house of timber and gave directions for the erection of a new building of masonry to cost £4,000 - if possible, but not to exceed £5,000.  A plan had been obtained from an English architect, Edward O'Brien, but this was amended by George Strickland Kingston, who had come to South Australia as an assistant to the Surveyor General, William Light, and who had had some experience in architecture and building. When Kingston received tenders for the proposed work they were in the vicinity of £7,000. After further amendment of the plans to reduce the cost, a contract was let to the builders, Messrs East and Breeze. After Governor Gawler was recalled to England in 1841, partly because of his "extravagant" building programs, his successors George Grey and Lieutenant Colonel Frederick Holt Robe found it necessary to spend the least possible amount on the house.  The earliest part of the House to be built was the east wing of the present building. It was completed and occupied in May 1840. Government House is thus probably the second oldest continuously occupied house in the State, after Walkley cottage in St Mark's College, Pennington Terrace, North Adelaide, which was first occupied in mid-1839. When completed, Government House consisted of the present main Drawing Room, Morning Room, Small Dining Room, and upstairs there were three bedrooms, a dressing room and two small servants' rooms. Governors, their families and house guests make use of all the upstairs rooms.  It was listed on the South Australian Heritage Register on 24 July 1980 and on the defunct Register of the National Estate on 21 March 1978,

Summer residences.

Governors formerly used a summer residence in the Adelaide Hills to escape the heat of the Adelaide Plains. Two buildings were used for this purpose. The first of these, Old Government House, was built in what is now the Belair National Park in 1860. In 1880, this building was superseded by a larger residence at Marble Hill near Norton Summit, until it was destroyed in the Black Sunday Bushfire of 1955. Subsequently, the Governor was not provided with a summer residence.

Functions.

Government House is located in well kept grounds which are periodically used for important public ceremonies, such as:

Environs.

Cottages were built in the northern part of the grounds, originally for the butler (1928) and the chauffeur (1945). The grounds of Government House itself are surrounded by prominent public buildings, statues and memorials:

Government House, located in Adelaide on the corner of North Terrace and King William Road, is the official residence of the Governor of South Australia.

总督府(Government House)是位于澳大利亚南澳大利亚州城市阿德莱德北露台和威廉国王路路口的一座建筑,也是南澳大利亚州州长的官邸。最初的总督府修建于1830年代。现在的总督府建筑兴建于1940年,是当时南澳大利亚州的第二大建筑。由于阿德莱德夏季炎热,因此南澳大利亚州州长在夏季居住在其他地区。