CONGESTIVE HEART FAILURE Assignment Example | Topics and Well Written Essays - 750 words

CONGESTIVE HEART FAILURE - Assignment Example There are two primary conditions that are significantly associated with the situation in which the heart fails. They include systolic heart and diastolic heart failure (UCSF Medical Center 2015). Moreover, CHF is said to be a condition that occurs gradually and may take the time to be noticed. A reflection on CHF will help in understanding the signs and symptoms, as well as staging. The staging will focus on New York Heart Association (NYHA) classifications as well as the American College of Cardiology/American Heart Association (ACC/AHA) risk stages of patients. There are various signs and symptoms of CHF. The first significant sign of the condition is challenges of breathing also known as dyspnea (American Heart Association, 2015). The challenges of breathing are common when one is engaging in any activity. However, it may occur during rest or while sleeping, and it may be sudden to a level of waking ones up (American Heart Association, 2015). Sometimes one may experience challenges of breathing while lying flat. Moreover, one may wake up tired and feel unsettled. All these challenges are associated with the blood returning to the pulmonary veins as the heart is unable to maintain the supply (American Heart Association, 2015). The other major thing is coughing or wheezing that occurs for a long time. It is characterized by the production of white or pink blood-tinged mucus (American Heart Association, 2015). The reason for this characteristic is the presence of fluids in the lung. In addition, their body has excess fluid also known as edem a. The symptom is characterized by swelling mostly in the feet, ankles, legs, as well as weight gain (American Heart Association, 2015). The symptom is caused by retention of fluid in various tissues and also by inability if the kidney to discharge waste. The affected individual also feels tired. Tiredness is evident in all task one carries in a day. The reason for tiredness is the

Describe and explain the value of industrial location models Essay Example for Free

Describe and explain the value of industrial location models Essay What is an industrial location model? [5] 1) A model is a mathematical representation that is used to show why patterns have occurred, or to predict how things will occur in the future. A location model shows why certain things have located in certain spaces and aims to show where they will locate in the future. An industrial location model therefore aims to show why industry has located in the area it has, and where it will locate in the future. The term industry includes primary, secondary, tertiary and quaternary sectors. All sides of industry can be incorporated in these models, this includes tertiary and primary as well as secondary employment, although most models are designed with manufacturing specifically in mind. There are many types of industrial location model. Weber designed a model that showed where secondary manufacturing industry would locate based on the weight of raw materials used and the weight of the final product. Smith (1971) built an alternative to Webers model, which is more updated and takes into account new types of transport and industries other than secondary. There are also models such as the behavioural matrix which attempt to show what type of companies are more likely to choose the optimum location for their business. Describe and explain the value of industrial location models [20] 2) A model of industrial location put forward by Alfred Weber in 1909 assumes that industrialists choose a least-cost location for the development of new industry. The theory is based on a number of assumptions. Weber assumes that there is a flat relief, uniform transport, culture, climate, labour costs, political and economic system, and that markets are of fixed size and location. It is also assumed that transport costs are proportional to the weight of the goods and the distance covered by the goods, and that perfect competition exists. One of the main assumptions is that raw materials are either ubiquitous or localised. Ubiquitous raw materials are found everywhere and are evenly distributed, and therefore would affect industrial location e.g. water and clay. Localised raw materials are not evenly distributed. Weber suggested that raw materials and markets would attract the location of an industry due to transport costs. Industries with a high material index would be pulled towards the raw material. Industries with a low material index would be pulled towards the market. The material index is calculated by dividing the total weight of raw materials by the total weight of the finished product. A material index of much greater than 1 indicates that there is a loss of weight during the manufacturing process; for example butter making. The factory should therefore locate near to the raw material. A material index of less than 1, where weight is gained during manufacturing, would locate near to the market. An index of less than 1 could be achieved by an industry using largely ubiquitous materials, like water, as in the brewing industry. Once a least-cost location has been established through the material index, Weber considers the effect of labour costs in deflecting industry away from the least cost location. Isodapanes are constructed to determine the area within which an industry can locate without losing money. The critical isodapane is the greatest distance an industry can locate from the least-cost location without losing money. If a source of cheap labour lies within an isodapane below the critical isodapane, it would be more profitable to choose the site with low labour costs rather than the least transport costs location. Weber also takes into account agglomeration of industries, the model suggests that some factories locate within critical isodapanes of other factories, to share resources labour and transport costs. Webers model doesnt relate well to modern conditions. This is because it doesnt take into account many recent developments such as reduced costs of transport and government intervention. Weber assumes a lot of things that in reality wouldnt be found e.g. perfect knowledge of the market, and physical geography is ignored. Weber also ignores changes in costs and sources of raw materials over time. Overall Webers model is largely applicable to heavy industries only. In 1971 David Smith provided an alternative to Webers model of industrial location. Smith suggested that as profits could be made anywhere where the total income is greater than total costs, then although there is a point of maximum profit, there would be a larger area where production is possible and profit is still made. Smith suggested that industries rarely located at the least-cost location, but more often at a sub optimum and practical location. He suggested that this was due to imperfect knowledge about production and market demand, imperfect decision makers, who can be influenced by other factors, or may not act rationally, or a government policy, which may tempt industry to locate in areas of high unemployment or development areas. Smiths model takes into account all types of transport although a circular margin of profitability is rarely produced in real life. Where Webers model can only be used for secondary manufacturing Smiths model can easily be modified to include all types of industry. However Smiths model is based entirely on money and other factors such as employees needs are not taken into account. The UK iron and steel production is a good example of industrial location compared to Weber and Smiths models. Before the 1600s, iron making was found near to outcrops of ore, where there were plenty of trees, e.g. Forest of Dean, because transport was poor and they were unable to move raw materials large distances. This fits Webers model because iron making would have a material index of greater than one, due to iron ore being much greater in weight than the iron produced as the finished product. However Webers model says that a resource such as trees will be ubiquitous, which is not the case here. After 1700 coke began to be used to smelt iron more efficiently. The new furnaces were located near coalmines, where coal would have been the heaviest raw material to transport e.g. Sheffield and South Wales. This fits Webers model. Today the coalmines have run out, but the industry hasnt relocated because good transport systems mean that ores and coal can be transported in from abroad. This complies with Smiths model because profit has been made in a sub optimum location. Other reasons for the iron and steel industry remaining in the same areas are large amounts of labour and agglomeration, which are covered in Webers model.

Free Narrative Essays - Advertising and Personal Values :: Personal Narrative Essays

Advertising and Personal Values      Ã‚  Ã‚  Ã‚  Ã‚   I just discovered that I don't know anything about today's society. This of course came as a shock.   I had thought that I was an informed citizen but I now know otherwise. this enlightenment came at great cost in time, and effort.   The time was spent in watching television for an hour. The effort was to not lose my sanity for unlike any other hour of TV, this time I was forced to actually watch the commercials.   The values that TV presents seem to be different than what I was taught as a child. Advertisers seem to present their own version of morality and values. Their idea of morality might not coincide with ours, but it does sell their products.      Ã‚  Ã‚  Ã‚  Ã‚   Wait, I just learned that if I buy my wife an anniversary band she will know that I love her.   But of course the band is a few thousand dollars.   Oh wait, easy financing is a valuable.   Darn I missed the small print that was flashed for two seconds on the bottom of the screen.   Oh well it must not have been important.   Wont my wife love me even if I can't afford to buy her this bracelet?   I wonder if this is going to leave an impression on anyone with an anniversary coming up?   Could that be the intention?      Ã‚  Ã‚  Ã‚  Ã‚   If I want to enjoy work I had better listen to the lite fm 93.9., and for lunch I can run out to Arby's for 99 cent roast beef sandwiches, but only for a limited time.   And if those roast beef sandwiches get me sick I can go to Osco and get some medicine twenty-four hours a day.   All of these ads just came rapid fire.   Is this playing upon my need for instant gratification?   Are the advertisers trying to get me to hurry?      Ã‚  Ã‚  Ã‚  Ã‚   I have to go see a Jeep dealer so I can outrun a bull in heat, but I better be careful if I get it to dirty the pigs will fall in love with it.   Wow is that a nice Jeep, but what is the price anyway?   And is it practical to own a vehicle that can go anywhere on or off the road?

Turkish Economy Essay examples -- essays research papers

Turkish Economy - Structure and Grwoth At the time of the collapse of the Ottoman Empire during World War I, the Turkish economy was underdeveloped: agriculture depended on outmoded techniques and poor-quality livestock, and the few factories producing basic products such as sugar and flour were under foreign control. Between 1923 and 1985, the economy grew at an average annual rate of 6 percent. In large part as a result of government policies, a backward economy developed into a complex economic system producing a wide range of agricultural, industrial, and service products for both domestic and export markets. Economic Development At the birth of the republic, Turkey's industrial base was weak because Ottoman industries had been undermined by the capitulations. World War I and the War of Independence (1919-22) also had extensively disrupted the Turkish economy. The loss of Ottoman territories, for example, cut off Anatolia from traditional markets. Agricultural output--the source of income for most of the population--had dropped sharply as peasants went to war. Even the production of wheat, Turkey's main crop, was insufficient to meet domestic demand. In addition, massacres and the emigration of Greeks, Armenians, and Jews, who had dominated urban economic life, caused a shortage of skilled laborers and entrepreneurs. Turkey's economy recovered remarkably once hostilities ceased. From 1923 to 1926, agricultural output rose by 87 percent, as agricultural production returned to prewar levels. Industry and services grew at more than 9 percent per year from 1923 to 1929; however, their share of the economy remained quite low at the end of the decade. By 1930, as a result of the world depression, external markets for Turkish agricultural exports had collapsed, causing a sharp decline in national income. The government stepped in during the early 1930s to promote economic recovery, following a doctrine known as etatism (see Glossary). Growth slowed during the worst years of the depression but between 1935 and 1939 reached 6 percent per year. During the 1940s, the economy stagnated, in large part because maintaining armed neutrality during World War II increased the country's military expenditures while almost entirely curtailing foreign trade. After 1950 the country suffered economic disruptions about once a decade; the most serious crisis occurred in the late... ...h. Structure of the Economy In the years after World War II, the economy became capable of supplying a much broader range of goods and services. By 1994 the industrial sector accounted for just under 40 percent of GDP, having surpassed agriculture (including forestry and fishing), which contributed about 16 percent of production. The rapid shift in industry's relative importance resulted from government policies in effect since the 1930s favoring industrialization (see fig. 8). In the early 1990s, the government aimed at continued increases in industry's share of the economy, especially by means of export promotion. Services increased from a small fraction of the economy in the 1920s to just under half of GDP by 1994. Several factors accounted for the growth of the services sector. Government--already sizable under the Ottomans--expanded as defense expenditures rose; health, education, and welfare programs were implemented; and the government work force was increased to staff the numerous new public organizations. Trade, tourism, transportation, and financial services also became more important as the economy developed and diversified. ________________________________________

Daddy’s gunna get you!

In Drama we made up a play about a girl Jo who becomes possessed by her friends late father, we got the idea from a story that Miss Risk read out to the class, the story was like a mystery story and contained clues to why this person called Jo was found at the waste ground, the clues where little like, her posters were torn off the walls and her mirror was smashed into pieces in which her mother saw and followed to find the girl at the site, we made sure we used the clues in our play as well as other ideas that we came up with such as, my friend Charlotte came up with the idea of using a ouiga board for the possession and another friend that I worked with called Nina came up with the idea of the destroyed, haunted house were the wasteland currently is. We all came up with many ideas, some which we could not use because we found them hard to do or they became confusing to the audience, one of these ideas was that we inserted flash backs and forwards, as if the audience was seeing what the girl went through to see where she is now but we got confused doing it so we figured if we were confused and we knew what was going on in the play, we realised that an audience who had never even seen the play before would have no idea what was going on so we had to cut those scenes out. In my play I worked in a small group, which consisted only of four people, those people were: Nina Elliott Charlotte Ireland Zoe Hammett And of course myself, the parts we played were significant and individual to the actress and character in the play. Charlotte played the part of Jo's friend, Sophia; she is a shy girl she dresses very girly and acts sweet and innocent, Sophia is really a very nice girl she has just been bought into the wrong crowd of people. She lives with her Mum and her Step-Dad near Jo's house. Sophia and her Mum have recently been falling out over the fact that Sophia wants to know her real father, her mother is too scared to tell her because Sophia might find out the secret of what really happened and she doesn't know how her new husband (Sophia's Step-Dad) will react, Sophia only wants to know a few things about him, she doesn't see the problem she just wants too know, What he looked like, his name and most importantly weather or not he is still alive, She is a very curious character and is quite easily pushed into things, Sophia is almost a complete opposite of My character. The character I play is Jo, a girl with a few problems (although she doesn't like to admit it) She dresses in a gothic style and doesn't care what people think or say about her, she doesn't care about other peoples feelings just as long as she gets what she wants and she would never do anything for anyone else if she doesn't see what she can get out of it. She is definitely a character that most people would call a bully. The people she hangs around with are outcasts like herself, they have been disowned by their old friends because things like the way they look, act or their insecurity problems, all they really have friend wise now is each other. Although Jo tries to hide it she really loves the super natural but because of her gothic style she hides her emotions (Well except her sarcasm) My friend Nina played the part of Lavender another of Jo's out-casted friends; she is more ‘down to earth' and mellow, she dresses like a hippy but also like Jo loves the super natural but unlike Jo she does hide it; she studies it, she studies a lot of what she is into and is dying to know what has been covered up in the small village they live in (if anything at all) Lavender is the one who brings the ouiga board to school and catches Jo's attention with it. Lavenders mother doesn't mind at all about her looking and studing things like that as long as she doesn't try them inside the house that is what brings it all to Jo's house because no way would Sophia even touch the thing let alone let it into the house and that is one thing she was not going to be pushed into. Zoe played the part of police woman and the mother to all three girls, she didn't want a main part and we did not give her one because she is away a lot of the time from lessons which is the only time we would get to rehearse it. I choose the people I did to work with because I know them well and they are my friends, I knew they would have very good ideas to contribute to the play and I know how very talented they are at acting I knew that whatever the part maybe that they would be capable of reaching out and helping me construct the play from every tiniest detail of reactions and facial expressions, the people I choose to work with encouraged me and each other when we need help, we helped with constructive criticism and by being not only actresses but directors as well. The play was about a young girl named Jo who was found at the wasteland near her home, we made up a play showing how she got to that stage and what happened afterwards, In the first scene Jo's friend Sophia is arguing with her mother about the whereabouts of her real father, when the scene changes to school we see the first appearance of Jo and her friend Lavender, Lavender is reading a book and Jo is looking impatient, they talk about the whereabouts of Sophia until she turns up at which the subject is changed to ouiga boards and they all end up agreeing to meet up at 6 at Jo's house. Then comes another scene between Sophia and her mother, her mother is about to tell her something but then her Step-Dad walks in the house and her mother stops. The scene changes to Jo's room where they attempt the ouiga board only to conjure up a spirit which possess Jo to tear all her posters down smash her mirror and write on the wall in her own blood she then stumbles to the waste ground where the taunting screams of ghosts make her faint. The scene at school Jo comes in late her friends are scared of her by the way she acted and ask her why her mum let her to school where she explains she blamed it on them, Sophia refuses to use the board again while as Lavender is pushed into it, Lavender then goes on to ask her mother about what happened to her friend, her mum tells her that her friend has been possessed and Sophia mother finally tells her of her father, his name, his looks and the fact that he is no longer alive. Lavender and Jo are about to use the ouiga board again when Sophia walks in, the spirit in Jo awakens again and everyone figures out that the spirit is Sophia's Father, Sophia shoots Jo in the arm causing her to collapse in pain, there is then scenes of the after effects. The scene where Jo is put into the â€Å"special care† unit the police take Sophia away, Lavender is put under a protection unit where she is given a new name address and identity, and then as a last scene they show Sophia what she has meant to have done to her friend where Jo is talking to herself and going crazy locked up in a padded cell. My character is quite lazy and doesn't seem bothered by those around her, she slumps in her chair in the 1sst scene and in the second scene you see her she's sitting on her bed grumpily, the expressions show that she tries to maintain a high authority, the voice and accent she speaks in is quite nasty but isn't really an accent there and if there is id have to say it is a London accent. The way my character moves, when u do see her walking you can tell that she doesn't really like what she is doing and she shuffles her feet, she is not a very active person and remains in a grumpy, sad mood through out the whole play except when she is possessed when she becomes psycho and angry and her expressions tell the other people in the play that she doesn't like them and she gives them evils. As time went on while I was practising my piece I came more familiar with my character, I found out that the more she looked like she didn't worry about anything the more she seemed it and the more she acted it, people commented that when I was in my part and dressed up as my character I seemed like I was actually gothic and the way I acted was as if a real gothic person would act and that the comments I made where really sarcastic, In my final performance we performed it quite well but not as well as it could have been, we made some changes at the end to try and make it better but it ended up because we didn't have enough time to practise this part, it all went wrong. What we tried doing was too add a music scene at the end with all the end consequences mimed and only turning the music down at one point to hear what the police officers are saying to Lavender. The idea of our piece at first to me was to pass a drama exam but as time went on I realised that our play could be actually passing on a message to the audience, the message to me that was being passed onto the audience was that things are not always easy and that people need to work things out and that playing with ouiga boards is not a game but is a serious business that can have very serious effects. I think my character displayed an attitude of soloism amongst her friends I think the audience realised that she gained the respect and that all the events seemed to revolve around her house and that it was her friends that she dragged into it and that if it wasn't for her none of the events would have happened. Overall I was happy with the play that we performed, I felt my character role was important to the piece and I felt that I played this role well, my friends in my group encouraged me when I needed it and gave me constructive criticism when I needed it, I felt like I have learnt a lot about how bad life can get from this play, I have learnt that even though peoples lives might look cheerful inside they might be hurting more then anyone else. I have also learnt more dramatic skills and feel that these will help me in the future for when I perform other roles. I have learnt that in a play the characters mood at the beginning is how the audience interprets them through out the entire play. I am really happy with the play e have produced and hope that my future performances will be just as good or better.

Drug Legalization Essays - Drug Control Law, Drug Culture

Drug Legalization Essays - Drug Control Law, Drug Culture Drug Legalization The debate over drugs and drug legalization is an increasingly important political issue as we proceed into the twenty-first century. It is important that we proceed into this era with a keen sense of direction on this issue. Whether we increase our current laws or we proceed in the direction legalization. It is obvious that some reformation of our current policy is needed. But, the drug legalization debate is not a issue that should only concern our political officials and law makers. It should concern all of us, since all of us are affected by the laws governing the trade and use of drugs. In this paper I will address the drug legalization debate from the view of the anti-legalist and the view of the legalist. I will also address the historical issues and arguments that lead to the prohibition on drugs and the subsequent War on Drugs. Before we look ahead to the debate over legalization, we should first look back at what took place to bring about the current drug prohibition. The drug hysteria first started around the turn of the century, by Orville Marshall who documented San Franciscos opium dens. In his report he documented the people who frequented these dens of sin. He found, that a significant number of the patrons were criminals of varying degree and classified the rest as the undesirables of society. What he proposed was for federal intervention in an attempt to lower crime and rid society of the scourge that drugs represented. The report lead to the Harrison Act of 1914, which restricted the use of opiates and cocaine to medicinal uses only. The Harrison Acts language is relatively vague leading to varied interpretations and throughout the years has become the cornerstone of the American drug prohibition. Leading to the formation of the DEA (Drug Enforcement Agency), in 1974. It has also allowed for further restrictions on the use of drugs for both personal and medicinal use. In recent times it has also served as a spring board for much of the recent legislature regarding mandatory minimums and the expansion of asset forfeiture laws. Which allows drug enforcement agencys to confiscate any and all property that is suspected to be related to the transportation or distribution of drugs. In most arguments regarding the legalization of drugs they are quick to point out that the drug prohibition is doomed to the failure of the Eighteenth Amendment (alcohol prohibition). Anti-legalist point out that this is not the case. That much like the prohibition on alcohol, in 1919, it is unrealistic for us to think that we can totally prevent the use or sale of drugs. But, much like the prohibition on alcohol our goal is to limit the consumption of drugs and thereupon lessen its effects on society. According to Mark(1) Moore, Alcohol consumption declined dramatically during Prohibition30 to 50 percent Cirrhosis death rates for men were 29.5 per 100,000 in 1911 and 10.7 in 1929. Admissions to state mental hospitals for alcoholic psychosis declined from 10.1 per 100,000 in 1919 to 4.7 in 1928. Further more, it is not to say that society was wrong to repeal Prohibition. A democratic society may decide that recreational drinking is worth the price in traffic fatalities and other consequences. But the common claim that laws backed by morally motivated political movements cannot reduce drug use is wrong. If the prohibition on alcohol really decreased alcohol use by 30 to 50 percent, in such a short time (14 years). The obvious question is, by how much has drug use been curtailed in the last 80 years of the prohibition on drugs? And, if it is a significant decrees wouldnt it be the most beneficial policy to keep on the road that we are currently on. If not increase the current penalties for drug violations. I should also add that after the repeal of prohibition alcohol use tripled and one year later had settled at a higher rate of use than before prohibition. Though we do not have any reliable information on the number of addicts before drug prohibition. There has been speculation that the misuse of drugs was at or above current levels of drug use. Raising the

50 Million Years of Horse Evolution

50 Million Years of Horse Evolution Apart from a couple of bothersome side branches, horse evolution presents a neat, orderly picture of natural selection in action. The basic storyline goes like this: as the woodlands of North America gave way to grassy plains, the tiny proto-horses of the Eocene epoch (about 50 million years ago) gradually evolved single, large toes on their feet, more sophisticated teeth, larger sizes, and the ability to run at a clip, culminating in the modern horse genus Equus. There are a number of prehistoric horses, including 10 essential prehistoric horses to know. As part of the evolution of horses, you should also know the recently extinct horse breeds. This story has the virtue of being essentially true, with a couple of important ands and buts. But before we embark on this journey, its important to dial back a bit and place horses in their proper position on the evolutionary tree of life. Technically, horses are perissodactyls, that is, ungulates (hoofed mammals) with odd numbers of toes. The other main branch of hoofed mammals, the even-toed artiodactyls, are represented today by pigs, deer, sheep, goats, and cattle, whereas the only other significant perissodactyls beside horses are tapirs and rhinoceroses. What this means is that perissodactyls and artiodactyls (which counted among the mammalian megafauna of prehistoric times) both evolved from a common ancestor, which lived only a few million years after the demise of the dinosaurs at the end of the Cretaceous period, 65 million years ago. In fact, the earliest perissodactyls (like Eohippus, the earliest identified common ancestor of all horses) looked more like small deer than majestic equines! Hyracotherium and Mesohippus, the Earliest Horses Until an even earlier candidate is found, paleontologists agree that the ultimate ancestor of all modern horses was Eohippus, the dawn horse, a tiny (no more than 50 pounds), deer-like herbivore with four toes on its front feet and three toes on its back feet. The giveaway to Eohippus status  was its posture: this perissodactyl put most of its weight on a single toe of each foot, anticipating later equine developments. Eohippus was closely related to another early ungulate, Palaeotherium, which occupied a distant side branch of the horse evolutionary tree. Five to ten million years after Eohippus/Hyracotherium came Orohippus (mountain horse), Mesohippus (middle horse), and Miohippus (Miocene horse, even though it went extinct long before the Miocene epoch). These perissodactyls were about the size of large dogs and sported slightly longer limbs with enhanced middle toes on each foot. They probably spent most of their time in dense woodlands, but may have ventured out onto the grassy plains for short jaunts. Epihippus, Parahippus, and Merychippus- Moving Toward True Horses During the Miocene epoch, North America saw the evolution of intermediate horses, bigger than Eohippus and its ilk but smaller than the equines that followed. One of the most important of these was Epihippus (marginal horse), which was slightly heavier (possibly weighing a few hundred pounds) and equipped with more robust grinding teeth than its ancestors. As you might have guessed, Epihippus also continued the trend toward enlarged middle toes, and it seems to have been the first prehistoric horse to spend more time feeding in meadows than in forests. Following Epihippus were two more hippi, Parahippus and Merychippus. Parahippus (almost horse) can be considered a next-model Miohippus, slightly bigger than its ancestor and (like Epihippus) sporting long legs, robust teeth, and enlarged middle toes. Merychippus (ruminant horse) was the largest of all these intermediate equines, about the size of a modern horse (1,000 pounds) and blessed with an especially fast gait. At this point, its worth asking the question: what drove the evolution of horses in the fleet, single-toed, long-legged direction? During the Miocene epoch, waves of tasty grass covered the North American plains, a rich source of food for any animal well-adapted enough to graze at leisure and run quickly from predators if necessary. Basically, prehistoric horses evolved to fill this evolutionary niche. Hipparion and Hippidion, the Next Steps Toward Equus Following the success of intermediate horses like Parahippus and Merychippus, the stage was set for the emergence of bigger, more robust, more horsey horses. Chief among these were the similarly named Hipparion (like a horse) and Hippidion (like a pony). Hipparion was the most successful horse of its day, radiating out from its North American habitat (by way of the Siberian land bridge) to Africa and Eurasia. Hipparion was about the size of a modern horse; only a trained eye would have noticed the two vestigial toes surrounding its single hooves. Lesser known than Hipparion, but perhaps more interesting, was Hippidion, one of the few prehistoric horses to have colonized South America (where it persisted until historical times). The donkey-sized Hippidion was distinguished by its prominent nasal bones, a clue that it had a highly developed sense of smell. Hippidion may well turn out to have been a species of Equus, making it more closely related to modern horses than Hipparion was. Speaking of Equus, this genus- which includes modern horses, zebras, and donkeys- evolved in North America during the Pliocene epoch, about four million years ago, and then, like Hipparion, migrated across the land bridge to Eurasia. The last Ice Age saw the extinction of both North and South American horses, which disappeared from both continents by about 10,000 BCE. Ironically, though, Equus continued to flourish on the plains of Eurasia and was reintroduced to the Americas by the European colonizing expeditions of the 15th and 16th centuries CE.