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SUMMARY / RELATED TOPICS

Pectin

Pectin is a structural acidic heteropolysaccharide contained in the primary cell walls of terrestrial plants. Its main component is a sugar acid derived from galactose, it was first described in 1825 by Henri Braconnot. It is produced commercially as a white to light brown powder extracted from citrus fruits, is used in food as a gelling agent in jams and jellies, it is used in dessert fillings, sweets, as a stabilizer in fruit juices and milk drinks, as a source of dietary fiber. In plant biology, pectin consists of a complex set of polysaccharides that are present in most primary cell walls and are abundant in the non-woody parts of terrestrial plants. Pectin is a major component of the middle lamella, where it helps to bind cells together, but is found in primary cell walls. Pectin is deposited by exocytosis into the cell wall via vesicles produced in the golgi; the amount and chemical composition of pectin differs among plants, within a plant over time, in various parts of a plant. Pectin is an important cell wall polysaccharide that allows primary cell wall extension and plant growth.

During fruit ripening, pectin is broken down by the enzymes pectinase and pectinesterase, in which process the fruit becomes softer as the middle lamellae break down and cells become separated from each other. A similar process of cell separation caused by the breakdown of pectin occurs in the abscission zone of the petioles of deciduous plants at leaf fall. Pectin is a natural part of the human diet, but does not contribute to nutrition; the daily intake of pectin from fruits and vegetables can be estimated to be around 5 g if 500 g of fruits and vegetables are consumed per day. In human digestion, pectin binds to cholesterol in the gastrointestinal tract and slows glucose absorption by trapping carbohydrates. Pectin is thus a soluble dietary fiber. In non-obese diabetic mice pectin has been shown to increase the incidence of diabetes. A study found that after consumption of fruit the concentration of methanol in the human body increased by as much as an order of magnitude due to the degradation of natural pectin in the colon.

Pectin has been observed to have some function in repair the DNA of some types of plant seeds desert plants. Pectinaceous surface pellicles, which are rich in pectin, create a mucilage layer that holds in dew that helps the cell repair its DNA. Consumption of pectin has been shown to reduce blood LDL cholesterol levels; the effect depends upon the source of pectin. The mechanism appears to be an increase of viscosity in the intestinal tract, leading to a reduced absorption of cholesterol from bile or food. In the large intestine and colon, microorganisms degrade pectin and liberate short-chain fatty acids that have positive influence on health. Pectins known as pectic polysaccharides, are rich in galacturonic acid. Several distinct polysaccharides have been characterised within the pectic group. Heterogalacturonans are linear chains of α--linked D-galacturonic acid. Substituted galacturonans are characterized by the presence of saccharide appendant residues branching from a backbone of D-galacturonic acid residues.

Rhamnogalacturonan I pectins contain a backbone of the repeating disaccharide: 4)-α-D-galacturonic acid--α-L-rhamnose-(1. From many of the rhamnose residues, sidechains of various neutral sugars branch off; the neutral sugars are D-galactose, L-arabinose and D-xylose, with the types and proportions of neutral sugars varying with the origin of pectin. Another structural type of pectin is rhamnogalacturonan II, a less frequent, complex branched polysaccharide. Rhamnogalacturonan II is classified by some authors within the group of substituted galacturonans since the rhamnogalacturonan II backbone is made of D-galacturonic acid units. Isolated pectin has a molecular weight of 60,000–130,000 g/mol, varying with origin and extraction conditions. In nature, around 80 percent of carboxyl groups of galacturonic acid are esterified with methanol; this proportion is decreased to a varying degree during pectin extraction. Pectins are classified as high- vs. low-methoxy pectins, with more or less than half of all the galacturonic acid esterified.

The ratio of esterified to non-esterified galacturonic acid determines the behavior of pectin in food applications - HM-pectins can form a gel under acidic conditions in the presence of high sugar concentrations, while LM-pectins form gels by interaction with divalent cations Ca2+, according to the idealized ‘egg box’ model, in which ionic bridges are formed between calcium ions and the ionised carboxyl groups of the galacturonic acid. In high-ester/high-methoxy pectins at soluble solids content above 60% and a pH-value between 2.8 and 3.6, hydrogen bonds and hydrophobic interactions bind the individual pectin chains together. These bonds form; these form a 3-dimensional molecular net. The gelling-mechanism is called sugar-acid-pectin gel. While low-ester/low-methoxy pectins need calcium to form a gel, they can do so at lower soluble solids and higher pH-values than high-ester pectins. Low-ester pectins form gels with a range of pH from 2.6 to 7.0 and with a soluble solids content between 10 and 70%.

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Christopher Pinney

Christopher Pinney is an anthropologist and art historian, Professor of Anthropology and Visual Culture at University College London in the department of anthropology. He is known for his studies on the visual culture of South Asia India, he was honoured by the Government of India, in 2013, by bestowing on him the Padma Shri, the fourth highest civilian award, for his contributions to the field of literature. Christopher Pinney has travelled India and his collection of chromolithographs cover the rural Madhya Pradesh during the turn of the century, cultural festivals like Kumbh Mela and Rang Panchami, historical sites such as Hussain Tekri, Bheruji Mandir, South Park Street Cemetery and Indian Museum in Kolkata, places like Nepal and Sri Lanka. Pinney has worked and taught at many institutions such as Australian National University, University of Chicago, University of Cape Town, Jawaharlal Nehru University, he works as Professor of Anthropology and Visual Culture at the University College, London and as the Crowe Visiting Professor of Art History at the Northwestern University.

Christopher Pinney has published many books and Camera Indica: The Social Life of Indian Photographs, Photos of the Gods and The Coming of Photography in India are some of the notable ones. Pinney has collaborated in the publication of many journals and other publications in the capacity of Editor, he was the co-editor of Beyond aesthetics: Art and the technologies of enchantment and the nation: the history and consumption of public culture in India,. "Padma Awards List". Indian Panorama. 2014. Retrieved 12 October 2014

Rosaline Smith

Rosaline J. Smith is a Sierra Leonean politician and member of parliament representing the All People's Congress party. Rosaline J. Smith is the member of parliament for Constituency 103 in the Western Urban, she is one of the few women members of parliament in her country. In 2012 when she first stood for parliament, there were 38 other female candidates and 548 males candidates. During the Ebola crisis in 2015, she represented Sierra Leone's Parliamentary Committee on Foreign Affairs to present relief items to National Ebola Response Centre. Rosaline represented her country among delegates made up of global leaders who participated in the sixth assembly of the International Renewable Energy Agency conference in 2016 in Abu Dhabi, she cemented her country's commitment to join the ongoing global energy transition by stating that "We have to have broad stakeholders’ participation in renewable energy. In that way, we are sure that we don’t have only a technological revolution, but a broad social movement."

William Bernoudy

William Adair Bernoudy was an American architect. Bernoudy was born in St. Louis where he attended the Washington University in St. Louis School of Architecture (now Sam Fox School of Design & Visual Arts, he studied under Frank Lloyd Wright in the 1930s. He is noted for the many modernist homes and public buildings he designed in the St. Louis area; the heyday of his work was in the 1950s. The William A. Bernoudy Residency in Architecture at the American Academy in Rome is named in his honor. In fall of 2019, the Sam Fox School of Design & Visual Arts of Washington University in St. Louis will dedicate its new William A. Bernoudy Architecture Studio thanks to a $1.5 million gift from the Gertrude & William A. Bernoudy Foundation. Located within Anabeth and John Weil Hall, under construction as part of the university’s east end transformation project, the 6,580-square-foot studio will provide state-of-the-art facilities for the school’s Graduate School of Architecture & Urban Design, he died in 1988.

12166 Conway Road 63141 23 Villa Coublay Drive, Frontenac, MO 63131 457 Osage Ridge Road, Augusta, MO 63332 25 Balcon Estates, Creve Coeur, MO 63141 6937 West Otsego Lake Drive, Gaylord, MI 49730-1958 446 North Warson Road, St. Louis, MO 63124 Saint Louis Zoo North Entrance, MO 63112 Beaumont Pavilion in Washington University in St. Louis, MO 63105 Thomas Jefferson School's Gymnasium, St. Louis, MO 63127 Overby, Osmund. William Adair Bernoudy, Architect: Bringing the Legacy of Frank Lloyd Wright to St. Louis. University of Missouri Press. Http://www.stlouisarchitecture.org/pdf/BernoudyLocations.pdf

Tetrahedral molecular geometry

In a tetrahedral molecular geometry, a central atom is located at the center with four substituents that are located at the corners of a tetrahedron. The bond angles are cos−1 = 109.4712206...° ≈ 109.5° when all four substituents are the same, as in methane as well as its heavier analogues. Methane and other symmetrical tetrahedral molecules belong to point group Td, but most tetrahedral molecules have lower symmetry. Tetrahedral molecules can be chiral. Aside from all saturated organic compounds, most compounds of Si, Ge, Sn are tetrahedral. Tetrahedral molecules feature multiple bonding to the outer ligands, as in xenon tetroxide, the perchlorate ion, the sulfate ion, the phosphate ion. Thiazyl trifluoride is tetrahedral. Other molecules have a tetrahedral arrangement of electron pairs around a central atom; however the usual classification considers only the bonded atoms and not the lone pair, so that ammonia is considered as pyramidal. The H–N–H angles are 107°, contracted from 109.5°. This difference is attributed to the influence of the lone pair which exerts a greater repulsive influence than a bonded atom.

Again the geometry is widespread so for complexes where the metal has d0 or d10 configuration. Illustrative examples include tetrakispalladium, nickel carbonyl, titanium tetrachloride. Many complexes with incompletely filled d-shells are tetrahedral, e.g. the tetrahalides of iron and nickel. In the gas phase, a single water molecule has an oxygen atom surrounded by two hydrogens and two lone pairs, the H2O geometry is described as bent without considering the nonbonded lone pairs. However, in liquid water or in ice, the lone pairs form hydrogen bonds with neighboring water molecules; the most common arrangement of hydrogen atoms around an oxygen is tetrahedral with two hydrogen atoms covalently bonded to oxygen and two attached by hydrogen bonds. Since the hydrogen bonds vary in length many of these water molecules are not symmetrical and form transient irregular tetrahedra between their four associated hydrogen atoms. Many compounds and complexes adopt bitetrahedral structures. In this motif, the two tetrahedra share a common edge.

The inorganic polymer silicon disulfide features an infinite chain of edge-shared tetrahedra. Inversion of tetrahedral occurs in organic and main group chemistry; the so-called Walden inversion illustrates the stereochemical consequences of inversion at carbon. Nitrogen inversion in ammonia entails transient formation of planar NH3. Geometrical constraints in a molecule can cause a severe distortion of idealized tetrahedral geometry. In compounds featuring "inverted" tetrahedral geometry at a carbon atom, all four groups attached to this carbon are on one side of a plane; the carbon atom lies at or near the apex of a square pyramid with the other four groups at the corners. The simplest examples of organic molecules displaying inverted tetrahedral geometry are the smallest propellanes, such as propellane; such molecules are strained, resulting in increased reactivity. A tetrahedron can be distorted by increasing the angle between two of the bonds. In the extreme case, flattening results. For carbon this phenomenon can be observed in a class of compounds called the fenestranes.

A few molecules have a tetrahedral geometry with no central atom. An inorganic example is tetraphosphorus which has four phosphorus atoms at the vertices of a tetrahedron and each bonded to the other three. An organic example is tetrahedrane with four carbon atoms each bonded to one hydrogen and the other three carbons. In this case the theoretical C−C−C bond angle is just 60°, representing a large degree of strain. AXE method Orbital hybridisation Examples of Tetrahedral molecules Animated Tetrahedral Visual Elmhurst College Interactive molecular examples for point groups 3D Chem – Chemistry, 3D Molecules IUMSC – Indiana University Molecular Structure Center] Molecular Modeling

Jens Janse

Jens Janse, is a Dutch footballer who plays as a right defender for Messina in the Italian Serie D. He played for Willem II, NAC Breda, Córdoba CF, Dinamo Tbilisi, Ternana and VVV-Venlo. Born in Venlo, Janse began playing football with amateur team MVC'19 from Maasbree, the town where he grew up; when he became older, he began playing for the youth teams of VVV-Venlo, the biggest club in the city where he was born. He was soon spotted by PSV Eindhoven. In PSV's youth, he played as a right winger, but after taking the advice of skills- and talent coach Ricardo Moniz, he instead began playing as a right back. After playing great as a right back, PSV wanted to offer him a first team contract, but because of the presence of Kasper Bøgelund, Michael Lamey, André Ooijer and Michael Reiziger, he was advised to play somewhere else. Willem II showed their interest, Janse decided to play in Tilburg. Janse was chosen to play for Willem II's first team at the beginning of the 2005–06 season. On 11 January 2006, Janse made his debut under the leadership of coach Kees Zwamborn in the match against Heracles Almelo.

The match ended in a 1–2 defeat for the Tricolores. Janse profiled himself by making an assist, getting a yellow card. In this season, Janse played in 8 more matches. Despite his good entrance in the Eredivisie for Willem II, it took a long time until he played again. Although, the 2006–07 season was marked as the great breakthrough of Janse; when his biggest competitor, Nuelson Wau, became injured, the road was paved for a fantastic season for Janse. He was the only bright spot for the chaos characterized club; because of his good performances for Willem II, his competitor Wau signed with Roda JC. On 24 January 2009, Janse made his first goal in the league in the away match against Feyenoord. Janse signed with Willem II's rivals, NAC Breda on 8 April 2010 and he will join the side after the 2009-10 season. On 7 July 2013, Janse signed with Córdoba. On 15 February 2014, Janse signed a contract with Dinamo Tbilisi. On 5 September 2014, Janse signed a contract with Ternana Calcio. On 20 September 2016 it was announced that Janse was joining Leyton Orient till the end of the 2016–17 season.

He was sent off 14 minutes into his debut against Plymouth Argyle. Jens Janse at Soccerway Jens Janse – UEFA competition record Jens Janse at WorldFootball.net