Cocaine known as coke, is a strong stimulant used as a recreational drug. It is snorted, inhaled as smoke, or dissolved and injected into a vein. Mental effects may include loss of contact with reality, an intense feeling of happiness, or agitation. Physical symptoms may include a fast heart rate and large pupils. High doses can result in high blood pressure or body temperature. Effects begin within seconds to last between five and ninety minutes. Cocaine has a small number of accepted medical uses such as numbing and decreasing bleeding during nasal surgery. Cocaine is addictive due to its effect on the reward pathway in the brain. After a short period of use, there is a high risk, its use increases the risk of stroke, myocardial infarction, lung problems in those who smoke it, blood infections, sudden cardiac death. Cocaine sold on the street is mixed with local anesthetics, quinine, or sugar, which can result in additional toxicity. Following repeated doses a person may have decreased ability to feel pleasure and be physically tired.
Cocaine acts by inhibiting the reuptake of serotonin and dopamine. This results in greater concentrations of these three neurotransmitters in the brain, it can cross the blood–brain barrier and may lead to the breakdown of the barrier. Cocaine is a occurring substance found in the coca plant, grown in South America. In 2013, 419 kilograms were produced legally, it is estimated. With further processing crack cocaine can be produced from cocaine. Cocaine is the second most used illegal drug globally, after cannabis. Between 14 and 21 million people use the drug each year. Use is highest in North America followed by South America. Between one and three percent of people in the developed world have used cocaine at some point in their life. In 2013, cocaine use directly resulted in 4,300 deaths, up from 2,400 in 1990; the leaves of the coca plant have been used by Peruvians since ancient times. Cocaine was first isolated from the leaves in 1860. Since 1961, the international Single Convention on Narcotic Drugs has required countries to make recreational use of cocaine a crime.
Topical cocaine can be used as a local numbing agent to help with painful procedures in the mouth or nose. Cocaine is now predominantly used for lacrimal duct surgery; the major disadvantages of this use are cocaine's potential for cardiovascular toxicity and pupil dilation. Medicinal use of cocaine has decreased as other synthetic local anesthetics such as benzocaine, proparacaine and tetracaine are now used more often. If vasoconstriction is desired for a procedure, the anesthetic is combined with a vasoconstrictor such as phenylephrine or epinephrine; some ENT specialists use cocaine within the practice when performing procedures such as nasal cauterization. In this scenario dissolved cocaine is soaked into a ball of cotton wool, placed in the nostril for the 10–15 minutes before the procedure, thus performing the dual role of both numbing the area to be cauterized, vasoconstriction; when used this way, some of the used cocaine may be absorbed through oral or nasal mucosa and give systemic effects.
An alternative method of administration for ENT surgery is mixed with adrenaline and sodium bicarbonate, as Moffett's solution. Cocaine is a powerful nervous system stimulant, its effects can last from 30 minutes to an hour. The duration of cocaine's effects depends on the route of administration. Cocaine can be in the form of fine white powder, bitter to the taste; when inhaled or injected, it causes a numbing effect. Crack cocaine is a smokeable form of cocaine made into small "rocks" by processing cocaine with sodium bicarbonate and water. Crack cocaine is referred to. Cocaine use leads to increases in alertness, feelings of well-being and euphoria, increased energy and motor activity, increased feelings of competence and sexuality. Coca leaves are mixed with an alkaline substance and chewed into a wad, retained in the mouth between gum and cheek and sucked of its juices; the juices are absorbed by the mucous membrane of the inner cheek and by the gastrointestinal tract when swallowed. Alternatively, coca leaves can be consumed like tea.
Ingesting coca leaves is an inefficient means of administering cocaine. Because cocaine is hydrolyzed and rendered inactive in the acidic stomach, it is not absorbed when ingested alone. Only when mixed with a alkaline substance can it be absorbed into the bloodstream through the stomach; the efficiency of absorption of orally administered cocaine is limited by two additional factors. First, the drug is catabolized by the liver. Second, capillaries in the mouth and esophagus constrict after contact with the drug, reducing the surface area over which the drug can be absorbed. Cocaine metabolites can be detected in the urine of subjects that have sipped one cup of coca leaf infusion. Orally administered cocaine takes 30 minutes to enter the bloodstream. Only a third of an oral dose is absorbed, although absorption has been shown to reach 60% in controlled settings. Given the slow rate of absorption, maximum physiological and psychotropic effects are attained 60 minutes after cocaine is administered by ingestion.
While the onset of these effects is slow, the effects are sustained for approxima
The blood vessels are a part of the circulatory system, microcirculation, that transports blood throughout the human body. These vessels are designed to transport nutrients and oxygen to the tissues of the body, they take waste and carbon dioxide and carry them away from the tissues and back to the heart. Blood vessels are needed to sustain life. There are three major types of blood vessels: the arteries, which carry the blood away from the heart; the word vascular, meaning relating to the blood vessels, is derived from the Latin vas, meaning vessel. Some structures -- such as cartilage, the epithelium, the lens and cornea of the eye -- do not contain blood vessels and are labeled avascular; the arteries and veins have three layers. The middle layer is thicker in the arteries than it is in the veins: The inner layer, tunica intima, is the thinnest layer, it is a single layer of flat cells glued by a polysaccharide intercellular matrix, surrounded by a thin layer of subendothelial connective tissue interlaced with a number of circularly arranged elastic bands called the internal elastic lamina.
A thin membrane of elastic fibers in the tunica intima run parallel to the vessel. The middle layer tunica media is the thickest layer in arteries, it consists of circularly arranged elastic fiber, connective tissue, polysaccharide substances, the second and third layer are separated by another thick elastic band called external elastic lamina. The tunica media may be rich in vascular smooth muscle. Veins don't have the external elastic lamina, but only an internal one; the tunica media is thicker in the arteries rather than the veins. The outer layer is the thickest layer in veins, it is made of connective tissue. It contains nerves that supply the vessel as well as nutrient capillaries in the larger blood vessels. Capillaries consist of little more than a layer of endothelium and occasional connective tissue; when blood vessels connect to form a region of diffuse vascular supply it is called an anastomosis. Anastomoses provide critical alternative routes for blood to flow in case of blockages. There is a layer of muscle surrounding the arteries and the veins which help contract and expand the vessels.
This creates enough pressure for blood to be pumped around the body. Blood vessels are part of the circulatory system, together with the blood; the biggest difference in the structure of arteries and veins is the presence of valves. Backflow of blood is prevented in arteries by the heart; however in veins, one-direction valves are used to prevent backflow as a result of a decrease in blood pressure as the blood passes through the circulatory system. There are various kinds of blood vessels: Arteries Elastic arteries Distributing arteries Arterioles Capillaries Venules Veins Large collecting vessels, such as the subclavian vein, the jugular vein, the renal vein and the iliac vein. Venae cavae. Sinusoids Extremely small vessels located within bone marrow, the spleen, the liver, they are grouped as "arterial" and "venous", determined by whether the blood in it is flowing away from or toward the heart. The term "arterial blood" is used to indicate blood high in oxygen, although the pulmonary artery carries "venous blood" and blood flowing in the pulmonary vein is rich in oxygen.
This is because they are carrying the blood to and from the lungs to be oxygenated. Blood vessels function to transport blood. In general and arterioles transport oxygenated blood from the lungs to the body and its organs, veins and venules transport deoxygenated blood from the body to the lungs. Blood vessels circulate blood throughout the circulatory system Oxygen is the most critical nutrient carried by the blood. In all arteries apart from the pulmonary artery, hemoglobin is saturated with oxygen. In all veins apart from the pulmonary vein, the saturation of hemoglobin is about 75%. In addition to carrying oxygen, blood carries hormones, waste products and nutrients for cells of the body. Blood vessels do not engage in the transport of blood. Blood is propelled through arterioles through pressure generated by the heartbeat. Blood vessels transport red blood cells which contain the oxygen necessary for daily activities; the amount of red blood cells present in your vessels has an effect on your health.
Hematocrit tests can be performed to calculate the proportion of red blood cells in your blood. Higher proportions result in conditions such as dehydration or heart disease while lower proportions could lead to anemia and long-term blood loss. Blood vessels transport red blood cells which contain the oxygen necessary for daily activities; the amount of red blood cells present in your vessels has an effect on your health. Hematocrit tests can be performed to calculate the proportion of red blood cells in your blood. Higher proportions result in conditions such as dehydration or heart disease while lower proportions could lead to anemia and long-term blood loss. Permeability of the endothelium is pivotal in the release of nutrients to the tissue, it is increased in inflammation in response to histamine and interleukins, which leads to most of the
Middle English was a form of the English language, spoken after the Norman conquest until the late 15th century. English underwent distinct developments following the Old English period. Scholarly opinion varies, but the Oxford English Dictionary specifies the period when Middle English was spoken as being from 1150 to 1500; this stage of the development of the English language followed the High to the Late Middle Ages. Middle English saw significant changes to its grammar and orthography. Writing conventions during the Middle English period varied widely. Examples of writing from this period that have survived show extensive regional variation; the more standardized Old English language became fragmented and was for the most part, being improvised. By the end of the period and aided by the invention of the printing press by Johannes Gutenberg in 1439, a standard based on the London dialect had become established; this formed the basis for Modern English spelling, although pronunciation has changed since that time.
Middle English was succeeded in England by the era of Early Modern English, which lasted until about 1650. Scots language developed concurrently from a variant of the Northumbrian dialect. During the Middle English period, many Old English grammatical features either became simplified or disappeared altogether. Noun and verb inflections were simplified by the reduction of most grammatical case distinctions. Middle English saw considerable adoption of Norman French vocabulary in the areas of politics, the arts and religion. Conventional English vocabulary retained its Germanic etiology, with Old Norse influences becoming more apparent. Significant changes in pronunciation took place involving long vowels and diphthongs which in the Middle English period, began to undergo the Great Vowel Shift. Little survives of early Middle English literature, due in part to Norman domination and the prestige that came with writing in French rather than English. During the 14th century, a new style of literature emerged with the works of writers including John Wycliffe and Geoffrey Chaucer, whose Canterbury Tales remains one of the most studied and read works of the period.
Transition from Late Old English to Early Middle English occurred in the latter part of the 11th century. The influence of Old Norse aided the development of English from a synthetic language with free word order, to a more analytic or isolating language with a more strict word order. Both Old English and Old Norse were synthetic languages with complicated inflections; the eagerness of Vikings in the Danelaw to communicate with their southern Anglo-Saxon neighbours resulted in the erosion of inflection in both languages. Old Norse may have had a more profound impact on Middle and Modern English development than any other language. Simeon Potter notes: "No less far-reaching was the influence of Scandinavian upon the inflexional endings of English in hastening that wearing away and leveling of grammatical forms which spread from north to south.". Viking influence on Old English is most apparent in the more indispensable elements of the language. Pronouns, comparatives, pronominal adverbs and prepositions, show the most marked Danish influence.
The best evidence of Scandinavian influence appears in extensive word borrowings, yet no texts exist in either Scandinavia or in Northern England from this period to give certain evidence of an influence on syntax. The change to Old English from Old Norse was substantive, of a democratic character. Like close cousins, Old Norse and Old English resembled each other, with some words in common, they understood each other, it is most "important to recognise that in many words the English and Scandinavian language differed chiefly in their inflectional elements. The body of the word was so nearly the same in the two languages that only the endings would put obstacles in the way of mutual understanding. In the mixed population which existed in the Danelaw these endings must have led to much confusion, tending to become obscured and lost." This blending of peoples and languages resulted in "simplifying English grammar."While the influence of Scandinavian languages was strongest in the dialects of the Danelaw region and Scotland, words in the spoken language emerge in the tenth and eleventh centuries near the transition from the Old to Middle English.
Influence on the written language only appeared at the beginning of the thirteenth century because of a scarcity of literary texts from an earlier date. The Norman conquest of England in 1066 saw the replacement of the top levels of the English-speaking political and ecclesiastical hierarchies by Norman rulers who spoke a dialect of Old French known as Old Norman, which developed in England into Anglo-Norman; the use of Norman as the preferred language of literature and polite discourse fundamentally altered the role of Old English in education and administration though many Normans of this period were illiterate and depended on the clergy for written communication and record-keeping. A significant number of words of French origin began to appear in the English language alongside native English words of similar meaning, giving rise to such Modern English synonyms as pig/pork, chicken/poultry, calf/veal, cow/beef, sheep/mutton, wood/forest, house/mansion, worthy/valuable, bold/courageous
In surgery or medical procedure, a ligature consists of a piece of thread tied around an anatomical structure a blood vessel or another hollow structure to shut it off. With a blood vessel the surgeon will clamp the vessel perpendicular to the axis of the artery or vein with a hemostat secure it by ligating it, it is different from a tourniquet in that the tourniquet will not be secured by knots and it can therefore be released/tightened at will. The principle of ligation is attributed to Hippocrates and Galen reintroduced some 1,500 years by Ambroise Paré, it found its modern use in 1870–80, made popular by Jules-Émile Péan. Hemostat Tourniquet Surgical suture List of medical topics Cheesewiring 4. Dunn DL, Phillips J, 2005 Wound Closure Manual, Ethicon, INC, Somerville, NJ
High-voltage direct current
A high-voltage, direct current electric power transmission system uses direct current for the bulk transmission of electrical power, in contrast with the more common alternating current systems. For long-distance transmission, HVDC systems may be less expensive and suffer lower electrical losses. For underwater power cables, HVDC avoids the heavy currents required to charge and discharge the cable capacitance each cycle. For shorter distances, the higher cost of DC conversion equipment compared to an AC system may still be justified, due to other benefits of direct current links. HVDC uses voltages between 100 kV and 1,500 kV. HVDC allows power transmission between unsynchronized AC transmission systems. Since the power flow through an HVDC link can be controlled independently of the phase angle between source and load, it can stabilize a network against disturbances due to rapid changes in power. HVDC allows transfer of power between grid systems running at different frequencies, such as 50 Hz and 60 Hz.
This improves the stability and economy of each grid, by allowing exchange of power between incompatible networks. The modern form of HVDC transmission uses technology developed extensively in the 1930s in Sweden and in Germany. Early commercial installations included one in the Soviet Union in 1951 between Moscow and Kashira, a 100 kV, 20 MW system between Gotland and mainland Sweden in 1954; the longest HVDC link in the world is the Rio Madeira link in Brazil, which consists of two bipoles of ±600 kV, 3150 MW each, connecting Porto Velho in the state of Rondônia to the São Paulo area. The length of the DC line is 2,375 km. In July 2016, ABB Group received a contract in China to build an ultrahigh-voltage direct-current land link with a 1100 kV voltage, a 3,000 km length and 12 GW of power, setting world records for highest voltage, longest distance, largest transmission capacity. High voltage is used for electric power transmission to reduce the energy lost in the resistance of the wires. For a given quantity of power transmitted, doubling the voltage will deliver the same power at only half the current.
Since the power lost as heat in the wires is directly proportional to the square of the current, doubling the voltage reduces the line losses by a factor of 4. While power lost in transmission can be reduced by increasing the conductor size, larger conductors are heavier and more expensive. High voltage cannot be used for lighting or motors, so transmission-level voltages must be reduced for end-use equipment. Transformers are used to change the voltage levels in alternating current transmission circuits. Transformers made voltage changes practical, AC generators were more efficient than those using DC; because of this, AC became dominant after the conclusion of the War of Currents in 1892. The War of Currents was a competition fought in the US between the DC system of Thomas Edison and the AC system of George Westinghouse. Practical conversion of power between AC and DC became possible with the development of power electronics devices such as mercury-arc valves and, starting in the 1970s, semiconductor devices as thyristors, integrated gate-commutated thyristors, MOS-controlled thyristors and insulated-gate bipolar transistors.
The first long-distance transmission of electric power was demonstrated using direct current in 1882 at Miesbach-Munich Power Transmission, but only 1.5 kW was transmitted. An early method of high-voltage DC transmission was developed by the Swiss engineer René Thury and his method was put into practice by 1889 in Italy by the Acquedotto De Ferrari-Galliera company; this system used series-connected motor-generator sets to increase the voltage. Each set was driven by insulated shafts from a prime mover; the transmission line was operated in a'constant current' mode, with up to 5,000 volts across each machine, some machines having double commutators to reduce the voltage on each commutator. This system transmitted 630 kW at 14 kV DC over a distance of 120 km; the Moutiers–Lyon system transmitted 8,600 kW of hydroelectric power a distance of 200 km, including 10 km of underground cable. This system used eight series-connected generators with dual commutators for a total voltage of 150 kV between the positive and negative poles, operated from c.1906 until 1936.
Fifteen Thury systems were in operation by 1913. Other Thury systems operating at up to 100 kV DC worked into the 1930s, but the rotating machinery required high maintenance and had high energy loss. Various other electromechanical devices were tested during the first half of the 20th century with little commercial success. One technique attempted for conversion of direct current from a high transmission voltage to lower utilization voltage was to charge series-connected batteries reconnect the batteries in parallel to serve distribution loads. While at least two commercial installations were tried around the turn of the 20th century, the technique was not useful owing to the limited capacity of batteries, difficulties in switching between series and parallel connections, the inherent energy inefficiency of a battery charge/discharge cycle. First proposed in 1914, the grid controlled mercury-arc valve became available for power transmission during the period 1920 to 1940. Starting in 1932, General Electric tested mercury-vapor valves and a 12 kV DC transmission line, which served to convert 40 Hz generation to serve 60 Hz loads, at Mechanicville, New York.
In 1941, a 60 MW, ±200 kV, 115 km buried cable
Edwin Smith Papyrus
The Edwin Smith Papyrus is an ancient Egyptian medical text, named after the dealer who bought it in 1862, the oldest known surgical treatise on trauma. This document, which may have been a manual of military surgery, describes 48 cases of injuries, wounds and tumors, it dates to Dynasties 16–17 of the Second Intermediate Period in ancient Egypt, c. 1600 BCE. The Edwin Smith papyrus is unique among the four principal medical papyri in existence that survive today. While other papyri, such as the Ebers Papyrus and London Medical Papyrus, are medical texts based in magic, the Edwin Smith Papyrus presents a rational and scientific approach to medicine in ancient Egypt, in which medicine and magic do not conflict. Magic would be more prevalent had the cases such as internal disease; the Edwin Smith papyrus is 15.3 feet in length. The recto has 377 lines in 17 columns. Aside from the fragmentary outer column of the scroll, the remainder of the papyrus is intact, although it was cut into one-column pages some time in the 20th century.
It is written right-to-left in hieratic, the Egyptian cursive form of hieroglyphs, in black ink with explanatory glosses in red ink. The vast majority of the papyrus is concerned with trauma and surgery, with short sections on gynaecology and cosmetics on the verso. On the recto side, there are 48 cases of injury; each case details the type of the injury, examination of the patient and prognosis, treatment. The verso side consists of five prescriptions; the spells of the verso side and two incidents in Case 8 and Case 9 are the exceptions to the practical nature of this medical text. Generic spells and incantations may have been used as a last resort in terminal cases. Authorship of the Edwin Smith Papyrus is debated; the majority of the papyrus was written by one scribe, with only small sections copied by a second scribe. The papyrus ends abruptly without any inclusion of an author, it is believed that the papyrus is an incomplete copy of an older reference manuscript from the Old Kingdom, evidenced by archaic grammar, terminology and commentary.
Breasted speculates - but emphasises that this is pure conjecture based on no evidence - that the author might be Imhotep, an architect, high priest, physician of the Old Kingdom, 3000–2500 BCE. The rational and practical nature of the papyrus is illustrated in 48 case histories, which are listed according to each organ. Presented cases are typical, not individual; the papyrus begins by addressing injuries to the head, continues with treatments for injuries to neck and torso, detailing injuries in descending anatomical order like a modern anatomical exposition. The title of each case details the nature of trauma, such as “Practices for a gaping wound in his head, which has penetrated to the bone and split the skull”; the objective examination process included visual and olfactory clues and taking of the pulse. Following the examination are the diagnosis and prognosis, where the physician judges the patient’s chances of survival and makes one of three diagnoses: “An ailment which I will treat,” “An ailment with which I will contend,” or “An ailment not to be treated”.
Last, treatment options are offered. In many of the cases, explanations of trauma are included to provide further clarity. Among the treatments are closing wounds with sutures, splints, poultices and curing infection with honey, stopping bleeding with raw meat. Immobilization is advised for spinal cord injuries, as well as other lower body fractures; the papyrus describes realistic anatomical and pathological observations. It contains the first known descriptions of the cranial structures, the meninges, the external surface of the brain, the cerebrospinal fluid, the intracranial pulsations. Here, the word ‘brain’ appears for the first time in any language; the procedures of this papyrus demonstrate an Egyptian level of knowledge of medicines that surpassed that of Hippocrates, who lived 1000 years later. The influence of brain injuries on parts of the body is recognized, such as paralysis; the relationship between the location of a cranial injury and the side of the body affected is recorded, while crushing injuries of vertebrae were noted to impair motor and sensory functions.
Due to its practical nature and the types of trauma investigated, it is believed that the papyrus served as a textbook for the trauma that resulted from military battles. The Edwin Smith Papyrus dates to Dynasties 16–17 of the Second Intermediate Period. Egypt was ruled from Thebes during this time and the papyrus is to have originated from there. Edwin Smith, an American Egyptologist, was born in Connecticut in 1822 – the same year Egyptian hieroglyphic writing was decoded. Smith purchased it in Luxor, Egypt from an Egyptian dealer named Mustafa Agha; the papyrus was in the possession of Smith until his death, when his daughter donated the papyrus to New York Historical Society. There its importance was recognized by Caroline Ransom Williams, who wrote to James Henry Breasted in 1920 about “the medical papyrus of the Smith collection” in hopes that he could work on it, he completed the first translation of the papyrus in 1930, with the medical advice of Dr. Arno B Luckhardt. Breasted’s translation changed the understanding of the history of medicine.
It demonstrates that Egyptian medical care was not limited to the magical modes of healing demonstrated in other Egyptian medical sources. Rational, scientific practices were constructed through observation and examination. From 1938 through 1948, the papyrus
The United States of America known as the United States or America, is a country composed of 50 states, a federal district, five major self-governing territories, various possessions. At 3.8 million square miles, the United States is the world's third or fourth largest country by total area and is smaller than the entire continent of Europe's 3.9 million square miles. With a population of over 327 million people, the U. S. is the third most populous country. The capital is Washington, D. C. and the largest city by population is New York City. Forty-eight states and the capital's federal district are contiguous in North America between Canada and Mexico; the State of Alaska is in the northwest corner of North America, bordered by Canada to the east and across the Bering Strait from Russia to the west. The State of Hawaii is an archipelago in the mid-Pacific Ocean; the U. S. territories are scattered about the Pacific Ocean and the Caribbean Sea, stretching across nine official time zones. The diverse geography and wildlife of the United States make it one of the world's 17 megadiverse countries.
Paleo-Indians migrated from Siberia to the North American mainland at least 12,000 years ago. European colonization began in the 16th century; the United States emerged from the thirteen British colonies established along the East Coast. Numerous disputes between Great Britain and the colonies following the French and Indian War led to the American Revolution, which began in 1775, the subsequent Declaration of Independence in 1776; the war ended in 1783 with the United States becoming the first country to gain independence from a European power. The current constitution was adopted in 1788, with the first ten amendments, collectively named the Bill of Rights, being ratified in 1791 to guarantee many fundamental civil liberties; the United States embarked on a vigorous expansion across North America throughout the 19th century, acquiring new territories, displacing Native American tribes, admitting new states until it spanned the continent by 1848. During the second half of the 19th century, the Civil War led to the abolition of slavery.
By the end of the century, the United States had extended into the Pacific Ocean, its economy, driven in large part by the Industrial Revolution, began to soar. The Spanish–American War and World War I confirmed the country's status as a global military power; the United States emerged from World War II as a global superpower, the first country to develop nuclear weapons, the only country to use them in warfare, a permanent member of the United Nations Security Council. Sweeping civil rights legislation, notably the Civil Rights Act of 1964, the Voting Rights Act of 1965 and the Fair Housing Act of 1968, outlawed discrimination based on race or color. During the Cold War, the United States and the Soviet Union competed in the Space Race, culminating with the 1969 U. S. Moon landing; the end of the Cold War and the collapse of the Soviet Union in 1991 left the United States as the world's sole superpower. The United States is the world's oldest surviving federation, it is a representative democracy.
The United States is a founding member of the United Nations, World Bank, International Monetary Fund, Organization of American States, other international organizations. The United States is a developed country, with the world's largest economy by nominal GDP and second-largest economy by PPP, accounting for a quarter of global GDP; the U. S. economy is post-industrial, characterized by the dominance of services and knowledge-based activities, although the manufacturing sector remains the second-largest in the world. The United States is the world's largest importer and the second largest exporter of goods, by value. Although its population is only 4.3% of the world total, the U. S. holds 31% of the total wealth in the world, the largest share of global wealth concentrated in a single country. Despite wide income and wealth disparities, the United States continues to rank high in measures of socioeconomic performance, including average wage, human development, per capita GDP, worker productivity.
The United States is the foremost military power in the world, making up a third of global military spending, is a leading political and scientific force internationally. In 1507, the German cartographer Martin Waldseemüller produced a world map on which he named the lands of the Western Hemisphere America in honor of the Italian explorer and cartographer Amerigo Vespucci; the first documentary evidence of the phrase "United States of America" is from a letter dated January 2, 1776, written by Stephen Moylan, Esq. to George Washington's aide-de-camp and Muster-Master General of the Continental Army, Lt. Col. Joseph Reed. Moylan expressed his wish to go "with full and ample powers from the United States of America to Spain" to seek assistance in the revolutionary war effort; the first known publication of the phrase "United States of America" was in an anonymous essay in The Virginia Gazette newspaper in Williamsburg, Virginia, on April 6, 1776. The second draft of the Articles of Confederation, prepared by John Dickinson and completed by June 17, 1776, at the latest, declared "The name of this Confederation shall be the'United States of America'".
The final version of the Articles sent to the states for ratification in late 1777 contains the sentence "The Stile of this Confederacy shall be'The United States of America'". In June 1776, Thomas Jefferson wrote the phrase "UNITED STATES OF AMERICA" in all capitalized letters in the headline of his "original Rough draught" of the Declaration of Independence; this draft of the document did not surface unti