Image ThermohalineCirculation 2.png A summary of the path of the thermohalinecirculation Great Ocean ... 400px right File ThermohalineCirculation using Improved Flow Field.ogv thumb 400px Thermohalinecirculation. The term thermohalinecirculation THC refers to a part of the large scale ocean circulation ... solids, dissolved substances and gases around the globe. As such, the state of the circulation has a large impact on the climate of the Earth . The thermohalinecirculation is sometimes called ... year 2002 month title What is the thermohalinecirculation? journal Science volume 298 issue ... to its freezing point of approximately 1.8 C. Movement of thermohalinecirculation Formation and movement ... climate The thermohalinecirculation plays an important role in supplying heat to the polar regions ... ref Changes in the thermohalinecirculation are thought to have significant impacts on the Earth s radiation budget . Insofar as the thermohalinecirculation governs the rate at which deep waters ... dioxide in the atmosphere. While it is often stated that the thermohalinecirculation is the primary ... circulation Hydrothermal circulation Upwelling Shutdown of thermohalinecirculation Footnotes Reflist ... oceanography DEFAULTSORT ThermohalineCirculation Category Physical oceanography Category Geological ... fa fr Circulationthermohaline gl Circulaci n termohalina ko hr Termohalinska ... thermohaline derives from thermo referring to temperature and salinity haline referring to salt ... to refer to the Zonal and meridional meridional overturning circulation often abbreviated ... of the circulation which is actually driven by temperature and salinity alone as opposed to other ... and salinity gradients can also lead to a circulation which does not add to the MOC itself. Overview ... saline the denser, and the colder the denser . There is often confusion over the components of the circulation ..., water masses of different densities must flow, providing a driving force for deep currents. The thermohaline ... more details
Image ThermohalineCirculation 2.png A summary of the path of the thermohalinecirculation. Blue paths ... or slowdown of the thermohalinecirculation is a postulated Effects of global warming effect of global warming . There is some speculation that global warming could, via a shutdown or slowdown of the thermohalinecirculation, trigger localised cooling in the North Atlantic and lead to cooling, or lesser ... 9.3.4.3 Thermohalinecirculation changes chapterurl http www.grida.no climate ipcc tar wg1 357.htm ... ?src climate ipcc tar wg1 index.htm isbn 0 521 80767 0 pb ISBNT 0 521 01495 6 ref Thermohalinecirculation ... Atlantic Drift, is part of the thermohalinecirculation THC , transporting warmth further north to the North ... could be provided to interrupt thermohalinecirculation yet the Younger Dryas are a case where ... impacts of a collapse of the Atlantic thermohalinecirculation journal Climatic Change volume 54 ... water flows large enough to shut down the thermohalinecirculation would be an order of magnitude ..., perhaps thermohalinecirculation reductions will not have the drastic effects that have been ..., a thermohalinecirculation shutdown could have other major consequences apart from cooling of Europe ... of the Atlantic ThermohalineCirculation date February 2005 work Avoiding Dangerous Climate ... October 2010 DEFAULTSORT Shutdown Of ThermohalineCirculation Category Climate change and the environment ..., rather than the reverse. In coupled global climate model Atmosphere Ocean General Circulation Models ... levels. The best known segment of this circulation is the Gulf Stream, a wind driven gyre , which transports .... This dense water then sinks and the circulation stream continues in a southerly direction ... Ocean General Circulation Models the THC tends to weaken somewhat rather than stop, and the warming ... H, Sand AB, Drange H, Hansen B, Valdimarsson H title Influence of the Atlantic subpolar gyre on the thermohalinecirculation journal Science volume 309 issue 5742 pages 1841 4 year 2005 month September ... more details
wiktionarypar circulationCirculation may refer to Circulatory system , a biological organ system whose primary function is to move substances to and from cells Circulation fluid dynamics , the path integral of the fluid velocity around a closed curve Circulation journal , one of the journals published by American Heart Association Circulation architecture , the flow of people through a building Exhaust gas recirculation , a nitrogen oxide reduction technique used in most gasoline and diesel engines Atmospheric circulation , the large scale movement of air Newspaper circulation , the average number of copies of a newspaper distributed on a day Magazine circulation , the average number of copies of a periodical distributed per edition volume Circulation UK duo , a UK house music duo Circulation problem , a generalization of network flow problems Library circulation , the activities around the lending of library books and other material to users of a lending library Circulation currency , all currency held by consumers and businesses, but not by financial institutions and governments Circulation Festival, an annual circus and Fire dancing fire performance festival held in Dunedin , New Zealand See also List of circulating currencies disambig ca Circulaci cs Kolob h es Circulaci n fr Circulation gl Circulaci n it Circolazione nl Circulatie pt Circula o ru simple Circulation ... more details
The term halothermal circulation refers to the part of the large scale ocean circulation that is driven by global Density gradient density gradients created by surface heat and evaporation. The adjective halothermal derives from salinity halo referring to salt content and thermo thermal referring to temperature, factors which together determine the Water molecule Density of saltwater and ice density of sea water . Halothermal circulation is driven primarily by salinity changes and secondarily by temperature changes as opposed to the Thermohalinecirculationthermohaline mode in modern oceans . The generation of high salinity surface waters at low latitudes, which were therefore of higher density and thus sank, is thought to have been the dominant ocean circulation driver during Greenhouse and icehouse Earth greenhouse climate s such as the Cretaceous . Similar dynamics operate today in the Mediterranean . The formation of bottom waters by halothermal dynamics is considered to be one to two orders of magnitude weaker than in thermohaline systems. See also References Kennett, J.P. & Stott, L.D., 1990, Proteus and Proto Oceanus, Paleogene oceans as revealed from Antarctic stable isotope results, ODP Leg 113. Proceedings Ocean Drilling Program, Science Results 113 , 865 880. physical oceanography Category Physical oceanography Category Geological processes ... more details
Sustainable development convection ocean current thermohalinecirculation metamorphic rocks volcanogenic ...Hydrothermal circulation in its most general sense is the circulation of hot water hydros in the Greek meaning water and thermos meaning heat. Hydrothermal circulation occurs most often in the vicinity of sources of heat within the Earth s Crust geology crust . This generally occurs near volcanic activity, but can occur in the deep crust related to the intrusion of granite , or as the result of orogeny or metamorphism . Seafloor hydrothermal circulation Hydrothermal circulation in the ocean s is the passage of the water through mid oceanic ridge systems. The term includes both the circulation of the well known, high temperature vent waters near the ridge crests, and the much lower temperature, diffusion diffuse flow of water through sediments and buried basalt s further from the ridge crests. The former circulation type is sometimes termed active , and the latter passive . In both cases the principle is the same cold dense seawater sinks into the basalt of the seafloor and is heated at depth whereupon it rises back to the rock ocean water interface due to its lesser density. The heat source for the active vents is the newly formed basalt, and, for the highest temperature vents, the underlying magma chamber. The heat source for the passive vents is the still cooling older basalts. Heat flow studies of the seafloor suggest that basalts within the oceanic crust take millions of years to completely cool as they continue to support passive hydrothermal circulation systems. Hydrothermal vent s are locations on the seafloor where hydrothermal fluids mix into the overlying ocean. Perhaps ... related hydrothermal circulation Hydrothermal circulation is not limited to ocean ridge environments ... with the groundwater system. Deep crust Hydrothermal also refers to the transport and circulation of water ... Hydrothermal circulation, particularly in the deep crust, is a primary cause of mineral deposit ... more details
Unreferenced date December 2009 A secondary circulation is a circulation induced in a rotating system. For example, the primary circulation of Earth s atmosphere is zonal . If however a parcel of air, that moves in a purely zonal direction, is accelerated or decelerated zonally, the Coriolis force will add a meridional component to its velocity. This meridional circulation is then the secondary circulation. See also Hough function Primitive equations Secondary flow DEFAULTSORT Secondary Circulation Category Geophysics Category Physical oceanography Category Atmospheric dynamics Category Fluid mechanics Fluiddynamics stub nn Sekund r sirkulasjon ... more details
Unreferenced stub auto yes date December 2009 Library circulation or library lending comprises the activities around the lending of library books and other material to users of a lending library . A circulation or lending department is one of the key departments of a library. The main public service point is the circulation desk or loans desk, usually found near the main entrance of a library. It provides lending services and facilities for return of loaned items. Renewal of materials and payment of fines are also handled at the circulation desk. Circulation staff may provide basic search and reference services, though more in depth questions are usually referred to reference librarians at the library reference desk . The circulation desk is in most cases staffed by library aides instead of professional librarians. Functions of the circulation desk staff may include Lending materials to library users Checking in materials returned Monitoring materials for damage and routing them to the appropriate staff for repair or replacement Troubleshooting circulation technology, i.e. library circulation software, scanners, printers, etc. Collecting statistics on library use, i.e. patron transactions, material checkouts, etc. See also Interlibrary loan Library reference desk DEFAULTSORT Library Circulation Category Library science Library stub ... more details
In the field of architecture , circulation refers to the way people move through and interact with a building. ref http www.britannica.com EBchecked topic 118392 circulationcirculation architecture in Britannica Online Encyclopedia ref In public buildings, circulation is of high importance for example, in buildings such as museums , it is key to have a floor plan that allows continuous movement while minimizing the necessity to retrace one s steps, allowing a visitor to see each work in a sequential, natural fashion. Structures such as elevator s, escalators , and staircases are often referred to as circulation elements, as they are positioned and designed to optimize the flow of people through a building. References references Category Architectural design Architecture stub ... more details
Unreferenced stub auto yes date December 2009 Collateral circulation is when an area of tissue or an organ has a number of different pathways for blood to reach it. This is often as a result of Circulatory anastomosis anastamoses branches formed between adjacent blood vessels. An example of the usefulness of collateral circulation is a systemic thrombo embolism in cats. This is when a thrombus lodges above the external iliac artery Common Iliac Artery , blocking the external and internal iliac arteries and effectively shutting off all blood supply to the hind leg. Even though the main vessels to the leg are blocked, enough blood can get to the tissues in the leg via the collateral circulation in order to keep them alive. Another example in Humans is where a person suffers an acute Myocardial Infarction Heart Attack , collateral circulation in the Heart tissue will sometimes by pass the blockage in the main artery and supply enough oxygenated blood to enable the Cardiac tissue to survive and recover. DEFAULTSORT Collateral Circulation Category Angiology Circulatory stub ... more details
Enteroenteric circulation is the secretion back into the intestines of substances previously taken up from it. It occurs when there is a negative relative concentration of substance in the intestines, making it passively diffuse from the mesenteric circulation into the intestinal lumen and is trapped. ref name CNYPCC http www.upstate.edu poison pdf tox newsletter 04 01toxnews.pdf The CNYPCC Toxicology Letter Vol. VI No. 2. Central New York Regional Poison Control Center. April, 2001 ref Examples of toxins that exhibit enteroenteric circulation include theophylline , phenobarbital , and phenytoin . ref name CNYPCC Administration of activated charcoal inhibits the enteroenteric circulation of such substances, and is therefore useful in overdose or intoxication. ref http www.medscape.com viewarticle 471331 medscape.com Use of Activated Charcoal in Drug Overdose. By Desiree Lie, MD, MSEd. Posted 25 March 2004 ref See also Enterohepatic circulation References Reflist Category Gastroenterology Medicine stub ... more details
A newspaper s circulation is the number of copies it distributes on an average day. Circulation is one of the principal factors used to set advertising rates. Circulation is not always the same as copies sold, often called paid circulation , since some newspapers are distributed without cost to the reader. Readership figures are usually higher than circulation figures because of the assumption that a typical ... claimed by the publisher. In many developed countries newspaper circulation is falling due to social ... developing countries circulation is increasing as these factors are more than cancelled out by rising incomes, population, and literacy. World newspapers with the largest circulation The World Association of Newspapers WAN publishes a list of newspapers with the largest circulation. In 2005, China topped the list in term of total newspaper circulation with 93.5 million a day, India came second ... Shimbun , Asahi Shimbun and Mainichi Shimbun are still the List of newspapers in the world by circulation ... by circulation largest circulated English language daily newspaper in the world, across ... in China. The List of newspapers in the United States by circulation largest circulated newspapers ... for a period of years but according to its own press kit, the circulation of USA Today declined ... circulation of the Soviet newspaper Komsomolskaya Pravda exceeded 21,500,000 in 1990, while the Soviet weekly Argumenty i Fakty boasted a circulation of 33,500,000 in 1991. Individual countries Belgium The Belgian institution CIM Centre for Information about Media publishes national circulation ... Volk . Canada see List of Canadian newspapers by circulation The most widely read paper in the country ... List of newspapers in India by circulation The 2010 Indian Readership Survey findings http www.newswatch.in ... Kerala, currently has a readership of over 9.9 million with a circulation base of over 2 million copies has the most circulation in regional languages. Japan main List of newspapers in Japan The 2004 ... more details
Infobox journal title Circulation cover File Circulation journal cover.gif editor Joseph Loscalzo discipline ... 7322 eISSN 1524 4539 boxwidth Circulation is a scientific journal published by Lippincott Williams ... ref 2008 saw the appearance of six subspecialty journals. The first edition of Circulation Arrhythmia ... pmid 19808386 ref followed by an edition dedicated to heart failure in May titled Circulation Heart Failure Circ Heart Fail . ref cite journal author Udelson JE title The inaugural issue of Circulation ... per month from July through October 2008. In order of release they were, Circulation Cardiovascular ... issue 1 pages 1 doi 10.1161 CIRCIMAGING.108.793083 ref Circulation Cardiovascular Interventions Circ Cardiovasc Intervent , ref cite journal author Faxon D title Circulation Cardiovascular Interventions ... 1 pages 1 doi 10.1161 CIRCINTERVENTIONS.108.799270 pmid 20031647 ref Circulation Cardiovascular Quality and Outcomes Circ Cardiovasc Qual Outcomes , ref cite journal author Krumholz H title Circulation ... 1 doi 10.1161 CIRCOUTCOMES.108.814509 pmid 20031779 ref and Circulation Cardiovascular Genetics Circ ... The Inauguration of Circulation Cardiovascular Genetics journal Circ Cardiovasc Genet year 2008 ... access policy All Circulation papers are available for free full text Open access publishing open access ... http circ.ahajournals.org Circulation home page http circep.ahajournals.org Circulation Arrhythmia and Electrophysiology home page http circheartfailure.ahajournals.org Circulation Heart Failure home page http circimaging.ahajournals.org Circulation Cardiovascular Imaging home page http circinterventions.ahajournals.org Circulation Cardiovascular Interventions home page http circoutcomes.ahajournals.org Circulation Cardiovascular Quality and Outcomes home page http circgenetics.ahajournals.org Circulation ... page DEFAULTSORT Circulation Journal Category Cardiology journals Category Publications established ... stub fr Circulation journal nl Circulation ja ... more details
Image Enterohepatic.JPG thumb right Enterohepatic Circulation. Distinguish2 the hepatic portal system which directs nutrient rich blood from the intestines to the liver Refimprove date July 2011 Enterohepatic circulation refers to the circulation of biliary acid s from the liver , where they are produced and secreted in the bile , to the small intestine , where it aids in digestion of fats and other substances, back to the liver. ref name urlSect. 6, Ch. 5 Enterohepatic Circulation of Bile Acids cite web url nowiki http www.lib.mcg.edu edu eshuphysio program section6 6ch5 s6ch5 17.htm nowiki Dead link date July 2011 title Sect. 6, Ch. 5 Enterohepatic Circulation of Bile Acids format work accessdate ref Endogenous bacteria play an important role in enterohepatic circulation. ref name urlMetabolic Activities of the Microflora cite book first1 Sherwood L. last1 Gorbach chapter Microbiology of the Gastrointestinal Tract pmid 21413258 chapterurl http www.ncbi.nlm.nih.gov books NBK7670 year 1996 editor1 first Samuel editor1 last Baron title Microbiology of the Gastrointestinal Tract edition 4th isbn 0 9631172 1 1 ref Hepatocytes metabolize cholesterol to cholic acid and chenodeoxycholic acid . These lipid soluble bile acid s are conjugated mainly to glycine or taurine molecules to form ... which are delivered to the duodenum will be recycled by the enterohepatic circulation. Due to the pH ... bile salts are reabsorbed actively into hepatic portal circulation. Bacteria deconjugate some of the primary ... absorbed into hepatic portal circulation. Finally, the conjugated bile acids which remained un ionized ..., and little escapes the healthy liver into systemic circulation. If bile does escape, jaundice may ... about 20 times, often multiple times during a single digestive phase. Drugs Enterohepatic circulation ... remain in the enterohepatic circulation for a prolonged period of time as a result of this recycling process. See also Enteroenteric circulation References reflist External links GPnotebook 1040580666 ... more details
With regards to a particular currency , circulation refers to the total value of that currency whether banknotes , coins , or demand deposits that is engaged in that currency s economy at a given time. ref http financial dictionary.thefreedictionary.com Currency in circulation Currency in circulation at the Free Online Dictionary ref Circulation can also refer to the metaphorical or literal movement of wealth due to transactions between the holders of a currency. The euro , the official currency of the European Union , is currently the currency with the highest combined value of cash circulation in the world. ref cite web last Atkins first Ralph title Euro notes cash in to overtake dollar publisher Financial Times date 2006 12 27 url http www.ft.com cms s 18338034 95ec 11db 9976 0000779e2340.html accessdate 2007 05 04 ref The money supply is defined to be the currency in circulation PLUS the money held in demand deposits, of which the latter makes up the greater part of the money supply. Therefore it seems clear that the currency in circulaton should NOT include demand deposits. Also common sense tells us that circulation refers to money that is readily available to spend for consumers businesses. Demand deposits are not only extremely high in currency value, but a minimum amount which is very large must be kept with the central bank at all times, in which case it s not in circulation, and therefore does not have the same liquidity as cash reserves not in a realistic sense anyway . The demand deposit can be used by a bank, but its use is generally a last resort, either in times of financial crisis, or when the central bank decides to increase interest rates by selling the bank ... the money in circulation since borrowers will borrow less due to the higher interest rates . Total currency in circulation In 1990 , total Money supply currency in circulation passed 1 Orders of magnitude ... ref See also List of circulating currencies References references DEFAULTSORT Circulation ... more details
Refimprove date April 2011 Image Illu pulmonary circuit.jpg thumb 400px Diagram of pulmonary circulation. Oxygen rich blood is shown in red oxygen depleted blood in blue. Pulmonary circulation is the half portion of the cardiovascular system which carries oxygen depleted blood away from the heart, to the lungs , and returns oxygenated oxygen rich blood back to the heart. The term pulmonary circulation is readily paired and contrasted with the systemic circulation . A separate system known as the bronchial circulation supplies blood to the tissue of the larger airways of the lung. Course Pulmonary circulation is the movement of blood from the heart, to the lungs, and back to the heart again. De oxygenated blood leaves the heart, goes to the lungs, and then re enters the heart oxygen poor blood leaves through the right ventricle through the pulmonary artery, the only artery in the body that carries oxygen poor blood, to the capillaries where carbon dioxide diffuses out of the blood cell into the alveoli, and oxygen diffuses out of the alveoli into the blood. Blood leaves the capillaries to the pulmonary vein, the only vein in the body that carries oxygen rich blood in the body, to the heart, where it re enters at the left atrium. Right heart Oxygen depleted blood from the body leaves the systemic circulation when it enters the right heart , more specifically the right atrium through ... circulation before returning again to the pulmonary circulation. History According to R.A. Young, Wiberg suggests that the early Ancient Greece Greeks knew of the circulation, and quotes a passage from ... bmj.1.4122.1 pmc 2176288 title The Pulmonary Circulation Before and After Harvey Part I year 1940 last1 Young first1 R. A. journal BMJ volume 1 issue 4122 pages 1 pmid 20782884 ref Pulmonary circulation ... until the dissections of William Harvey in 1616. Embryonic The pulmonary circulation loop is virtually bypassed in fetal circulation . The fetal lungs are collapsed, and blood passes from the right ... more details
Image Diagram of the human heart cropped .svg thumb 300px Systemic circulation is the part of the cardiovascular system which carries oxygen ated blood away from the heart to the body , and returns deoxygenated blood back to the heart. This physiologic theory of circulation was first described by William Harvey . This term is opposed and contrasted to the term pulmonary circulation first proposed by Ibn al Nafis . ref cite book last Maton first Anthea authorlink coauthors Jean Hopkins, Charles William McLaughlin, Susan Johnson, Maryanna Quon Warner, David LaHart, Jill D. Wright title Human Biology and Health publisher Prentice Hall year 1993 location Englewood Cliffs, New Jersey pages url doi id isbn 0 13 981176 1 ref Course Systemic circulation refers to the part of the circulatory system in which the blood leaves the heart, services the body s cells, and then re enters the heart. Blood leaves through the left ventricle to the aorta, the body s largest artery. The aorta leads to smaller arteries, arterioles, and finally capillaries. Waste and carbon dioxide diffuse out of the cell into the blood ... tree Oxygenated blood enters the systemic circulation when leaving the left ventricle , through the aortic semilunar valve . The first part of the systemic circulation is the aorta , a massive and thick ... atrium of the heart . Coronary vessels Main Coronary circulation The heart itself is supplied with oxygen and nutrients through a small loop of the systemic circulation. Portal veins The general rule ... portal vein branches into a second capillary system in the liver . Advantage Because the systemic circulation is powered by the left ventricle which is very muscular , one advantage of this form of circulation as opposed to open circulation , or the gill system that fish use to breathe is that there is simultaneous ... Dr. Matayoshi See also Pulmonary circulation Double circulatory system References Reflist cardiovascular ... Arteries of lower limbs DEFAULTSORT Systemic Circulation Category Angiology ar ... more details
Natural circulation refers to the ability of a fluid in a system to circulate continuously, with gravity and possible changes in heat energy. The difference of density being the only driving force. If the differences of density are caused by heat, this force is called as thermal head or thermal driving head. A fluid system designed for natural circulation will have a heat source and a heat sink . Each of these is in contact with some of the fluid in the system, but not all of it. The heat source is positioned lower than the heat sink. Most materials that are fluid at common temperatures expand when they are heated, becoming less density dense . Correspondingly, they become denser when they are cooled. At the heat source of a system of natural circulation, the heated fluid becomes lighter than the fluid surrounding it, and thus rises. At the heat sink, the nearby fluid becomes denser as it cools, and is drawn downward by gravity. Together, these effects create a flow of fluid from the heat source to the heat sink and back again. Systems of natural circulation include tornado es and other weather weather systems , ocean current s, and household Ventilation architecture ventilation . Some solar water heaters use natural circulation. The Gulf Stream circulates as a result of the evaporation ... Ocean, the water becomes so dense that it begins to sink down. In a nuclear reactor , natural circulation ... the heat sink . In this way, natural circulation will ensure that the fluid will continue ... fraction of full power under natural circulation, quieting those propulsion plants. The S6G reactor cannot operate at power under natural circulation, but can use it to maintain emergency cooling while shut down. By the nature of natural circulation, fluids do not typically move very fast, but this is not necessarily ..., even ones designed to primarily use natural circulation as the main method of fluid circulation, have pumps that can circulate the fluid in the case that natural circulation is not sufficient. See ... more details
A circulation plan is a schematic empirical projection model of how pedestrians and or motor vehicles flow through a given area, like, for example, a neighborhood or a Central Business District CBD . Circulation plans are used by city planners and other officials to manage and monitor traffic and pedestrian patterns in such a way that they might discover how to make future improvements to the system. ref Fisher, Brueggman Real Estate Finance and Investments , 14th edition. Chapter 16, Project Development ref The two types of people most cognizant of circulation plans are developers and local city and county planning officials. New multi family residential developments, for example, introduce increased volume and thus density of traffic flows into their vicinity. City planners might analyze this projected impact and justify charging higher impact fees. In other cases, local residents lobbying against a new development might use circulation plans to justify the denial of a development s building permit, citing decreased quality due to overcrowding, noise pollution, traffic, and so on. Good city planners do their best to use main thoroughfares and so on to draw commuter traffic out of local neighborhoods where excessive traffic is seen by local voters as undesirable and onto larger roads, which often utilize considerable buffers like setback land and vegetation to divorce non local commuter traffic from local neighborhood traffic. See also Impact fees Setback land use Zoning City Planning References reflist External Links Some examples City of Duluth Traffic Circulation Plan http www.dsmic.org default.asp?PageID 326 City of Placerville Pedestrian Circulation Plan http www.edctc.org 1 ASSETS CONTENT FOLDERS Non Motorized PVlePedPlan Ch 1 Introduction.pdf Category Road traffic management ... more details
Image Gray22.png thumb Human embryo of 2.6 mm. Image Gray458.png thumb Diagram of the vascular channels in a human embryo of the second week. After Eternod. The red lines are the dorsal aort continued into the umbilical arteries . The red dotted lines are the ventral aort , and the blue dotted lines the vitelline veins . Vitelline circulation refers to the system of blood flowing from the embryo to the yolk sac and back again. The yolk sac is situated on the ventral aspect of the embryo it is lined by endoderm , outside of which is a layer of mesoderm . It is filled with fluid, the vitelline fluid , which possibly may be utilized for the nourishment of the embryo during the earlier stages of its existence. Blood is conveyed to the wall of the sac by the primitive aort , and after circulating through a wide meshed capillary plexus , is returned by the vitelline veins to the tubular heart of the embryo. This constitutes the vitelline circulation, and by means of it nutritive material is absorbed from the yolk sac and conveyed to the embryo. External links GrayPage 54 http www.med.umich.edu lrc coursepages M1 embryology embryo 13cardiovascular system.htm Overview of three circulation systems Gray s Category Embryology of cardiovascular system ... more details
Hyperdynamic circulation is abnormally increased circulatory volume. Systemic vasodilation and the associated decrease in peripheral vascular resistance results in decreased pulmonary capillary wedge pressure and decreased blood pressure , often presenting with a collapsing pulse . In effort to compensate the heart will increase cardiac output and heart rate , which accounts for the decreased pulse pressure and sinus tachycardia . ref Mosby s Medical Dictionary, 8th edition. S.v. hyperdynamic circulation. Retrieved July 28, 2010 from http medical dictionary.thefreedictionary.com hyperdynamic circulation ref The condition sometimes accompanies septic shock , preeclampsia , and other physiological and psychiatric conditions. Possible causes Renal disease Volume expansion Anemia Anxiety Arteriovenous fistula AV fistulae Beriberi Erythroderma Exercise Liver failure Hepatic failure Hydrocephalus ref Greitz, Dan. Radiological Assessment of hydrocephalus new theories and implications for therapy. Neurosurg Rev 2004 27 145 165. ref Hypercapnia Paget s disease of bone Paget s disease Portal hypertension Pregnancy Pyrexia Thyrotoxicosis Vasodilator drugs References Reflist Category Cardiovascular diseases med stub ... more details
Orphan date February 2009 Brain circulation is a concept that is posited By whom date December 2009 Xiaonan Cao 1996 as a counter factual to the idea of brain drain . The concept of brain drain gained popularity as skilled labour from certain countries emigrated to other countries in search of better opportunities. In India for example, one witnessed large scale emigration of engineers from its premier engineering institutes called IIT Indian Institute of Technology in the sixties, seventies and eighties. Some commentators Who date March 2009 felt that this led to a loss of intellectual capital from the country and coined the term brain drain to signify this process. The late nineties and the early years of the 21st century however saw large numbers of these emigrants returning to India as prospects in India improved markedly, brought on by important economic reforms initiated in the early nineties. Some commentators Who date December 2009 now attribute India s success partly on this circular ... much intangible knowledge that proves invaluable for the country s development. Brain circulation can thus be defined as the circular movement of skilled labour across nations. Brain circulation vs brain ... it is able to tap into them, and such a process is called Brain Circulation. The story has been mixed ... brain circulation, while in others, brain circulation does not seem to happen in a significant way. Why brain circulation can be witnessed in certain contexts and not in others is a question that is at the forefront ... Circulation, National Science Foundation NSF 98 316 http www.nsf.gov statistics issuebrf ib98316.htm Kuznetsov, Yevgeny, 2005, From Brain Drain to Brain Circulation Emerging Policy Agenda, Presentation ... dp366.pdf Saxenian, AnnaLee, 2002, Brain Circulation How High Skilled Immigration Makes Everyone Better off, The Brookings Review, Vol 20, No.1 Saxenian, AnnaLee, 2005, From Brain Drain to Brain Circulation ... Bank Book on Brain Circulation Category Human migration ... more details
unreferenced date September 2008 Lost circulation can be one of the more serious problems that can arise during the drilling of an oil well or gas well . Circulation is said to be lost when the drilling fluid , known commonly as mud , flows into one or more geological formations instead of returning up the annulus oil well annulus . Consequences The consequences of lost circulation can be as little as the loss of a few dollars of drilling fluid , or as disastrous as a blowout well drilling blowout and loss of life, so close monitoring of tanks, pits, and flow from the well, to quickly assess and control lost circulation, is taught and practiced. If the fluid in the wellbore drops due to lost circulation or any other reason , hydrostatic pressure is reduced, thus allowing a gas or fluid, which is under a higher pressure than the reduced hydrostatic pressure , to influx into the wellbore . Another consequence of lost circulation is called dry drilling . Dry drilling occurs when fluid is completely lost from the well bore without actual drilling coming to a stop. The effects of dry drilling can be as minor as destroying a bit to as serious as major damage to the wellbore requiring a new ... the pipe, and the drilling rig itself. Categories Lost circulation falls into two main categories ... than 470 barrels 75 m sup 3 sup , or it takes greater than 48 hours to control or cease the lost circulation ... and the time involved in regaining circulation. Control Although preferred, ceasing lost circulation ... , which can lead to a blowout well drilling blowout . A number of options are available when lost circulation ... items in conjunction with, or followed by, a high viscosity fluid. If total losses occur and circulation ... if severe losses occur, as lost circulation can sometimes not be controlled with conventional or unconventional methods. Additives The most common additive used to control or cease lost circulation is bentonite ... of circulation, but can jeopardize the integrity of the wellbore itself. Additive Considerations Several ... more details
File Langmuir Circulation.jpg right thumb Langmuir circulation File Rodeo Lagoon From Trail.JPG thumb right White streaks in this lagoon are due to the Langmuir circulation. File Lines of sargassum Sargasso Sea.jpg thumb right These lines of sargassum can stretch for miles along the surface. The clumps of floating algae are often concentrated by the strong winds and wave action associated with the Gulf Stream . Langmuir circulation consists of a series of shallow, slow, counter rotating vortices at the ocean s surface. These circulations are developed when a particular type of wind blows steadily over the sea surface. Irving Langmuir discovered this phenomenon after observing windrow s of seaweed in the Sargasso Sea in 1938. ref The open university, Ocean circulation Butterworth Heinemann second edition 2001 ref Langmuir circulations usually circulate water with a depth of no more than 66 feet, which does not allow upwelling to bring nutrient rich waters from the pycnocline typically with a depth of more than 3000 feet to the ocean surface. The circulation was found to be 15 to the right of the wind in the northern hemisphere ref Stewart, Robert H., Introduction To Physical Oceanography , Copyright 2002 Fall 2002 Edition ref and the helix forming bands of divergence and Convergence zone convergence at the surface. At the convergence zones, there are commonly concentrations of floating seaweed, foam and debris along these bands. Along these divergent zones, the ocean surface is typically clear of debris since diverging currents force material out of this zone and into adjacent converging zones. On average, a particle in these vortices will complete a full revolution in one hour. At the surface the circulation will set a current from the divergence zone to the convergence zone and the spacing between these zones are of the order of 15 300 m. Below convergence zones ... Langmuir circulation physical oceanography Category Oceanography Category Physical oceanography ... more details
Multiple issues confusing August 2009 context August 2009 refimprove August 2009 Banknote s have a limited lifetime, after which they are collected for destruction, usually recycling or shredding . A banknote is removed from the money supply by bank s or other financial institution s due to everyday wear and tear from its handling. Banknote bundles are passed through a sorting machine that determines whether a particular note needs to be shredded, or are removed from the supply chain by a human inspector if they are deemed unfit for continued use for example, if they are mutilated or torn. Counterfeit banknotes are destroyed unless they are needed for evidentiary or forensic purposes. Contaminated banknotes are also decommissioned. A Canadian government report indicates Types of contaminant s include notes found on a corpse , stagnant water , contaminated by human or animal body fluid s such as urine, feces, vomit, infectious blood, fine hazardous powders from detonated explosives, dye pack and or drugs... These are removed from circulation primarily to prevent the spread of disease s. When taken out of circulation, Australia n bank notes are melted down and mixed together to form plastic garbage bin s. ref Singh, S.K. 2009 . Bank Regulations , Discovery Publishing House. ref Notes Reflist DEFAULTSORT Money Circulation Category Banknotes ru uk ... more details
Infobox company name Curtis Circulation Company logo caption type subsidiary traded as genre Only used with media and publishing companies fate predecessor successor foundation 1946 founder defunct location city New Milford, NJ location country USA location locations area served key people industry magazines products services Distribution br retail marketing br publisher support services revenue operating income net income aum Only used with financial services companies assets equity owner num employees parent Curtis Publishing Company 1946 1969 br Cadence Industries Perfect Film & Chemical Corporation br Cadence Industries 1969 1986 br Hachette Distribution Services br Lagardere SCA divisions subsid homepage http www.curtiscirc.com curtiscirc.com footnotes intl Curtis Circulation Company, LLC is a company that is in the magazines distribution business. It is also known for lending its name to an affiliated company, Marvel Comics Marvel Comics Group , for a line of magazines, Curtis Magazines . History Curtis Circulation Company started out as Curtis Publishing Company s circulation department, becoming an official subsidiary of in 1946. ref name bw cite news title Curtis Circulation Company, LLC Private Company Information url http investing.businessweek.com research stocks private snapshot.asp?privcapId 4761928 accessdate 23 August 2011 newspaper Business Week date August 23, 2011 ref In 1968, Cadence Industries Perfect Film & Chemical Corporation loaned 5 million to Curtis Publishing Company, publisher of the Saturday Evening Post , at the request of Curtis primary loan holder, First National Bank of Boston . ref name Time cite news title Magazines New Man for Curtis url ... date May 3, 1968 ref Despite attempts to revive the Post s circulation, and with the lack ... purchased Curtis Circulation that same year from Curtis Publishing Company . ref name nym cite news ..., it sold Curtis Circulation to Joseph M. Walsh and Hachette Distribution Services . ref name bw ... more details
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