In inorganic chemistry, bicarbonate is an intermediate form in the deprotonation of carbonic acid. It is a polyatomic anion with the chemical formula HCO−3. Bicarbonate serves a crucial biochemical role in the physiological pH buffering system; the term "bicarbonate" was coined in 1814 by the English chemist William Hyde Wollaston. The prefix "bi" in "bicarbonate" comes from an outdated naming system and is based on the observation that there is twice as much carbonate per sodium ion in sodium bicarbonate and other bicarbonates than in sodium carbonate and other carbonates; the name lives on as a trivial name. According to the Wikipedia article IUPAC nomenclature of inorganic chemistry, the prefix bi– is a deprecated way of indicating the presence of a single hydrogen ion; the recommended nomenclature today mandates explicit referencing of the presence of the single hydrogen ion: sodium hydrogen carbonate or sodium hydrogencarbonate. A parallel example is sodium bisulfite; the bicarbonate ion is an anion with the empirical formula HCO−3 and a molecular mass of 61.01 daltons.
It is isoelectronic with nitric acid HNO3. The bicarbonate ion carries a negative one formal charge and is an amphiprotic species which has both acidic and basic properties, it is both the conjugate base of carbonic acid H2CO3. A bicarbonate salt forms when a positively charged ion attaches to the negatively charged oxygen atoms of the ion, forming an ionic compound. Many bicarbonates are soluble in water at standard pressure. Bicarbonate is a vital component of the pH buffering system of the human body. 70%–75% of CO2 in the body is converted into carbonic acid, the conjugate acid of HCO−3 and can turn into it. With carbonic acid as the central intermediate species, bicarbonate – in conjunction with water, hydrogen ions, carbon dioxide – forms this buffering system, maintained at the volatile equilibrium required to provide prompt resistance to pH changes in both the acidic and basic directions; this is important for protecting tissues of the central nervous system, where pH changes too far outside of the normal range in either direction could prove disastrous.
Bicarbonate serves much in the digestive system. It raises the internal pH of the stomach, after acidic digestive juices have finished in their digestion of food. Bicarbonate acts to regulate pH in the small intestine, it is released from the pancreas in response to the hormone secretin to neutralize the acidic chyme entering the duodenum from the stomach. Bicarbonate is the dominant form of dissolved inorganic carbon in sea water, in most fresh waters; as such it is an important sink in the carbon cycle. In freshwater ecology, strong photosynthetic activity by freshwater plants in daylight releases gaseous oxygen into the water and at the same time produces bicarbonate ions; these shift the pH upward until in certain circumstances the degree of alkalinity can become toxic to some organisms or can make other chemical constituents such as ammonia toxic. In darkness, when no photosynthesis occurs, respiration processes release carbon dioxide, no new bicarbonate ions are produced, resulting in a rapid fall in pH.
The most common salt of the bicarbonate ion is sodium bicarbonate, NaHCO3, known as baking soda. When heated or exposed to an acid such as acetic acid, sodium bicarbonate releases carbon dioxide; this is used as a leavening agent in baking. The flow of bicarbonate ions from rocks weathered by the carbonic acid in rainwater is an important part of the carbon cycle. Ammonium bicarbonate is used in digestive biscuit manufacture. In diagnostic medicine, the blood value of bicarbonate is one of several indicators of the state of acid–base physiology in the body, it is measured, along with carbon dioxide, chloride and sodium, to assess electrolyte levels in an electrolyte panel test. The parameter standard bicarbonate concentration is the bicarbonate concentration in the blood at a PaCO2 of 40 mmHg, full oxygen saturation and 36 °C. Sodium bicarbonate Potassium bicarbonate Caesium bicarbonate Magnesium bicarbonate Calcium bicarbonate Ammonium bicarbonate Carbonic acid Carbon dioxide Carbonate Carbonic anhydrase Hard water Arterial blood gas Bicarbonates at the US National Library of Medicine Medical Subject Headings
Graciliraptor is a genus of theropod dinosaur from the early Cretaceous Period. It is a microraptorine dromaeosaurid; the type species Graciliraptor lujiatunensis was first named and described in 2004 by Xu Xing and Wang Xiaoling. The generic name is derived from Latin gracilis and raptor; the specific name refers to the village Lujiatun. Its fossil, holotype IVPP V 13474, was found in Liaoning Province, China; the type and only known specimen comprised part of the maxilla with some teeth, nearly complete fore and hind legs. It is estimated to have been about 90 centimetres long in life. In 2010, Gregory S. Paul gave higher estimations of 1.5 kilogrammes. Graciliraptor is lightly built for a non-avian theropod, with elongated middle caudal vertebrae and lower leg bones; the femur is thirteen centimetres long and total body length was estimated at one metre. The posterior articular processes of the tail vertebrae, or postzygapophyses, are connected by a thin bone sheath or lamina, that extends to the back over an eighth of the centrum of the following vertebra, thus further stiffening the middle tail immobilised by the typical dromaeosaurid long prezygapophyses.
Graciliraptor has been found in the lowest portions of the Yixian Formation, the Lujiatun Member, below the rocks where similar early dromaeosaurids were found. It is, in geological age, the oldest named dromaeosaurid, the oldest known from good fossil remains; as an early dromaeosaurid, Graciliraptor provided information on the early evolution and diversification of the group. It shares several characteristics in common with both early troodontids and avialan birds, supporting a close relationship between avialans and dromaeosaurids. Xu and Wang considered Graciliraptor to have been related to Microraptor, a similar dromaeosaurid from the younger Jiufotang Formation, it was placed in the Microraptorinae. Timeline of dromaeosaurid research A New Dromaeosaur from the Early Cretaceous Yixian Formation of Western Liaoning
Marvin Lee Hudson is a Major League Baseball umpire who began his career in the National League in 1999. He has officiated in the 2004 All-Star Game, six Division Series, two League Championship Series, the 2016 World Series, he wears uniform number 51. Prior to reaching the Major Leagues, Hudson served as an umpire in several minor leagues, beginning with the Appalachian League in 1992. From there, he moved on to the South Atlantic League for the following year, during which he spent time in the Florida Instructional League. After umpiring for the Florida State League in 1994, Hudson moved on to the Southern League in 1995 and 96, he officiated for the Hawaiian Winter League in 1995. After advancing all the way to the International League, where he umpired from 1997-1999, Hudson was promoted to the Major Leagues in 1999. Hudson was the home plate umpire for Armando Galarraga's near perfect game against the Cleveland Indians on June 2, 2010, was the second base umpire for Ervin Santana's 2011 no-hitter.
Hudson was umpiring at first base in Seattle on April 21, 2012, when Philip Humber threw a perfect game. He was at second base when six Seattle Mariners pitchers combined to no-hit the Los Angeles Dodgers on June 8, 2012. Hudson has officiated the World Baseball Classic in 2009 and 2013. MLB assigned him to the Legend Series at Rod Carew Stadium in Panama City, Panama from March 15–16, 2014, he studied Business Administration at Piedmont College, from which he graduated in 1986. Along with fellow umpire Mike DiMuro, Hudson helped start the Blue for Kids Foundation, now part of UMPS CARE. In 2015, Marvin Hudson founded Hudson 51 Official Wear, LLC, an officials equipment supply company based in Norcross, Georgia. List of Major League Baseball umpires Major League profile The Baseball Cube Retrosheet
In physics the Stoney units form a system of units named after the Irish physicist George Johnstone Stoney, who first proposed them in 1881. They are the first historical example of natural units, i.e. units of measurement designed so that certain fundamental physical constants serve as base units. The set of the constants that Stoney used as base units is the following: c, the speed of light in a vacuum, G, the gravitational constant, ke = 1/, the Coulomb constant, e, the elementary charge; this means that, in terms of Stoney units, the numerical values of all these constants equal one: c = G = k e = e = 1. Stoney's set of base units is similar to the one used in Planck units, proposed independently by Planck thirty years but Planck normalized the reduced Planck constant in place of the elementary charge. In Stoney units, the numerical value of the reduced Planck constant is not 1, but is ℏ = 1 α ≈ 137.0359991, where α is the fine-structure constant. Planck units are more used than Stoney units in modern physics quantum gravity.
Planck units are referred to as Planck–Stoney units. George Stoney was one of the first scientists to understand. James G. O’Hara pointed out in 1974 that Stoney’s derived estimate of the unit of charge, 10−20 ampere-second, was 1⁄16 of the modern value of the charge of the electron; the reason is that Stoney used the approximated value of 1018 for the number of molecules presented in one cubic millimetre of gas at standard temperature and pressure. Using the modern values for the Avogadro constant 6.02214×1023 mol−1 and for the volume of a gram-molecule of 22.4146×106 mm3, the modern value is 2.687×1016, instead of Stoney's 1018. The Stoney length and the Stoney energy, collectively called the Stoney scale, are not far from the Planck length and the Planck energy, the Planck scale; the Stoney scale and the Planck scale are the length and energy scales at which quantum processes and gravity occur together. At these scales, a unified theory of physics is thus required; the only notable attempt to construct such a theory from the Stoney scale was that of H. Weyl, who associated a gravitational unit of charge with the Stoney length and who appears to have inspired Dirac's fascination with the large number hypothesis.
Since the Stoney scale has been neglected in the development of modern physics, although it is still discussed. The Planck scale is valid for all known interactions, does not give prominence to the electromagnetic interaction, as the Stoney scale does. Dimensional analysis Natural units Physical constants Planck scale
This is a list of diplomatic missions of Niue, a small Pacific island country in Oceania. Although Niue is an associated state of New Zealand, it maintains diplomatic relations with 20 states. While Niue has self-rule, New Zealand manages its defence and foreign affairs at its request. Niue is classified as "Non-member State" by the UN and since 1994, after receiving declaration by New Zealand and the gradual evolution of Niue responsibility for its own foreign affairs, the UN Secretariat recognized the full treaty-making capacity of Niue and it signs treaties in its own name, it has overseas diplomatic mission in New Zealand. Due to the nature of the relationship with Niue, in 2001 in New Zealand a special law was passed to codify the diplomatic immunities enjoyed by the Niuean High Commission and its staff. Niue has permanent mission to the European Communities and permanent delegation to UNESCO. Mission in Brussels was established after Niue, in 2000, signed the Cotonou Convention between the member states of the European Union and the Africa-Caribbean-Pacific Group of States.
Zoogoneticus tequila, Tequila splitfin or Tequila fish, is a species of goodeid fish from Mexico. The specific epithet, derives from the Tequila Volcano, which looms near the type locality. Zoogoneticus tequila is endemic to the Ameca River basin in west-central Mexico, its current distribution is restricted to a single spring pool in Teuchitlán, only 4 metres in diameter, where a population consisting of less than 50 adult fish live. In this habitat, it is outnumbered by introduced guppies by a factor of six. Before the discovery of the pool population in 2000/2001, Zoogoneticus tequila was thought to inhabit rivers. Introduced fish species have been implicated in the disappearance of Zoogoneticus tequila from its type locality. Habitat deterioration may have contributed. Pollution and water extraction are threats to the pool. Captive populations are maintained by aquarists. Along with other Mexican goodeids, Zoogoneticus tequila are viviparous. Clutch size is up to 29 young. Males are smaller than females, with standard length up to 4.1 cm in males and up to 5.8 cm in females.
Total length can reach 7 cm in females. The sexes can be distinguished by colouration; the Goodeid Working Group: Zoogoneticus tequila