Evolution of the Human Heart into Four Chambers

Evolution of the Human Heart into Four Chambers The human heart does not look much like those Valentines Day candies or the pictures we drew on our love notes when we were in elementary school. The current human heart is a large muscular organ with four chambers, a septum, several valves, and other various parts necessary for pumping blood all around the human body. However, this amazing organ is a product of evolution and has spent millions of years perfecting itself in order to keep humans alive. Invertebrate Hearts Invertebrate animals have very simple circulatory systems. Many do not have a heart or blood because they are not complex enough to need a way to get nutrients to their body cells. Their cells are able to just absorb nutrients through their skin or from other cells. As the invertebrates become a little more complex, they use an open circulatory system. This type of circulatory system does not have any blood vessels or has very few. The blood is pumped throughout the tissues and filters back to the pumping mechanism. Like in earthworms, this type of circulatory system does not use an actual heart. It has one or more small muscular areas capable of contracting and pushing the blood and then reabsorbing it as it filters back. However, these muscular regions were the precursors to our complex human heart. Fish Hearts Of the vertebrates, fish have the simplest type of heart. While it is a closed circulatory system, it has only two chambers. The top is called the atrium and the bottom chamber is called the ventricle. It has only one large vessel that feeds the blood into the gills to get oxygen and then transports it around the fishs body. Frog Hearts It is thought that while fish only lived in the oceans, amphibians like the frog were the link between water-dwelling animals and the newer land animals that evolved. Logically, it follows that frogs would, therefore, have a more complex heart than fish since they are higher on the evolutionary chain. In fact, frogs have a three-chambered heart. Frogs evolved to have two atria instead of one, but still only have one ventricle. The separation of the atria allows frogs to keep the oxygenated and deoxygenated blood separate as they come into the heart. The single ventricle is very large and very muscular so it can pump the oxygenated blood throughout the various blood vessels in the body. Turtle Hearts The next step up on the evolutionary ladder is the reptiles. It was recently discovered that some reptiles, like turtles, actually have a heart that has a sort of a three and a half chambered heart. There is a small septum that goes about halfway down the ventricle. The blood is still able to mix in the ventricle, but the timing of the pumping of the ventricle minimizes that mixing of the blood. Human Hearts The human heart, along with the rest of the mammals, is the most complex having four chambers. The human heart has a fully formed septum that separates both the atria and the ventricles. The atria sit on top of the ventricles. The right atrium receives deoxygenated blood coming back from various parts of the body. That blood is then let into the right ventricle which pumps the blood to the lungs through the pulmonary artery. The blood gets oxygenated and then returns to the left atrium through the pulmonary veins. The oxygenated blood then goes into the left ventricle and is pumped out to the body through the largest artery in the body, the aorta. This complex, but efficient, way of getting oxygen and nutrients to body tissues took billions of years to evolve and perfect.

Two-Letter Words in Spanish

Two-Letter Words in Spanish If youve played Scrabble or similar games, you know how handy two-letter words can be. Thats true in Spanish versions of Scrabble as well as online games such as Apalabrados (Angry Words) and Wordfeud too. Following is a list of the two-letter words of Spanish that are listed in the Spanish Royal Academys dictionary, along with definitions and links to relevant articles and lessons. The list may not coincide with words that are legal to use in a specific game. Not all possible definitions are given. Words containing the combinations of ch and ll are also included here, as they used to be recognized as separate letters of the Spanish alphabet and are still treated as such in some games. ad - Word used in Latin phrases such as ad hoc ah - Interjection used to express sympathy and other emotions, sometimes similarly to ah aj - ailment (seldom used, and then usually in the plural) al - contraction of a el ar - interjection used in the military to order the immediate execution of a movement as - ace ax - ouch (antiquated) ay - ouch, oh be - the letter b bu - boo ca - a synonym for porque (antiquated) ce - the letter c cu - the letter q da - a conjugated form of dar de - of, from di - a conjugated form of dar do - do (first note of the musical scale) ea - interjection of encouragement or resolution eh - interjection used to get attention el - the masculine singular definite article en - in, on es - conjugated form of ser et - and (antiquated) ex - former fa - fa fe - faith fo - exclamation indicating displeasure or disgust fu - snort ge - the letter g ha - conjugated form of haber he - conjugated form of haber hi - shortened form of hijo (son) used in some expressions (antiquated) id - conjugated form of ir in - Word used in Latin phrases such as in promptu ir - to go ja - ha je - ha ji - ha; 22nd letter of the Greek alphabet ju - ha la - the feminine singular definite article le - a third-person object pronoun lo - a word of various uses as a pronoun or neuter definite article lle - variation of le (antiquated) me - me mi - my mu - moo na - contraction for en la (antiquated) ne - synonym for ni (antiquated) ni - nor no - no, not à ±a - shortened form of seà ±ora (antiquated) à ±o - shortened form of seà ±or (antiquated) à ±u - gnu oa - a Honduran childrens game oc - Occitan (a language related to Catalan) oh - oh os - the plural familiar second-person pronoun ox - interjection used to frighten birds and other animals pe - the letter p pi - pi pu - variation of puf (interjection used as a reaction to a bad smell) re - re (second note of the musical scale) ro - interjection, usually repeated, used in calming children se - the third-person reflexive pronoun so - under (rarely used); variation of su (antiquated); whoa su - his, her, your ta - interjection imitating a knock on a door te - you (as the second-person singular object pronoun) to - interjection used for calling dogs; whoa tu - second-person familiar singular possessive adjective (the pronoun form is tà º, although most games dont distinguish between accented and unaccented vowels) uf - whew, yuck uh - interjection of hesitation or disdain un - a, an, one va - conjugated form of ir ve - conjugated form of ver vi - conjugated form of ver xi - 14th letter of the Greek alphabet ya - adverb of vague meaning often used to add emphasis ye - the letter y yo - I (first-person singular subject pronoun)

The Capital Budget Research Paper Example | Topics and Well Written Essays - 1000 words

The Capital Budget - Research Paper Example Furthermore, better compensation increases the employee morale, generally, given that the increase is awarded in an equitable manner. In other words, employee morale is boosted if the increase in compensation is awarded in respect to the level of productivity of individual employees rather than granting a blanket increment Figure 1: Projected increase in Revenue to to increase in compensation Trend Analysis As shown in figure 2, annual expenditure has been greater than revenues for the past several years until 2002 when an opposite trend was observed. Generally, the expenditure has been declining since 2008. This rate of decline has been most drastic from 2011, but the management seems to be effectively controlling the operating expenses because the gap between revenues and expenditure seems to be closing up. It is very important for the management to ensure that as the cost declines, good measures should be put to ensure that the contribution margin does not decline as well (City of Cincinnati Ohio, 2012). 2008 2009 2010 2011 2012 Expenditure 365,000,000 356,000,000 356,000,000 354,000,000 334,000,000 Revenue 357,500,000 338,500,000 337,000,000 337,000,000 337,000,000 Table 1: Expenditure trend Figure 2: Expenditure Trend Expenditure Forecast The health expenditure, which finances the services by the city’s health clinics to those patients that are qualifying has been declining since 2010 and it is expected to maintain a slight decline to 2017. This cost should be approached because, although it consumes a substantial proportion of the council’s budget, health services are very fundamental and furthermore the decline shows that the council has been undertaking a cost cutting measure (City of Cincinnati Ohio, 2012). 2010 2011 2012 2013 2014 2015 2016 2017 Health 23,574,570 19,450,210 20,128,510 19,256,458 19,126,895 19,100,568 18,458,000 18,456,123 Fire 92,832,430 98,662,160 94,358,450 93,125,145 92,125,256 92,125,365 91,125,458 90,125,456 Public servivce 22,291,010 20,015,980 19,963,240 19,256,125 18,125,456 18,125,100 17,124,896 17,100,125 police 139,110,860 146,175,220 132,888,620 135,568,456 125,456,256 120,124,562 119,136,100 118,256,362 Figure 2: Four of the highest expenditure (5 years forecast) The fire expenditure seems to be consuming a very big proportion of the council’s budget, however, this expenditure has reduced since 2010 and the forecast exhibits the same trend of reduction. Therefore, this budget will be approved. Public services have a trend very similar with health and the cost cutting measures are evident, therefore, it is likely to be approved. Finally, the police takes the highest share of the council’s budget. Given that security is very essential as it determines the success of all other activities, the high budget is justifiable. It is also evident that this figure has been on the decline since 2012 and there it is likely to be approved (Weiss & Mark, 1989). Capital Budget There are t wo methods of predicting the cost of needed repairs including qualitative and quantitative methods. The qualitative forecasting methods make use of judgements to predict cost. This method is most suitable when used in situations where the historical data is not available. Furthermore, availability of historical data is sometimes considered irrelevant because of significant changes that take place in the environmental conditions afflicting the pertinent time. For instance, it

Single Soldiers Essay Example | Topics and Well Written Essays - 750 words

Single Soldiers - Essay Example The truth is that single soldiers make up more than a third of the United States’ army (BOSS site). These soldiers are fighting machines, dedicated to god and country. Nevertheless it helps them to have support at home and not to be all alone. The Army has recognized this, creating Better Opportunities for Single Soldiers (BOSS). According to its website: BOSS provides an avenue for single Soldiers to surface issues and to take part in activities but does not set policy and other guidance on issues. BOSS is intended to enhance command authority, prerogative, and responsibility in maintaining standards of conduct, good order, and discipline, not to dilute. This is an excellent first step in recognizing the problems faced by single soldiers. Drawing such people together into a cohesive unit in order to address their quality of life issues and their morale is a key development in the history of the evolution of the army. These individuals, often young, need sustenance. The Army can provide this too. There are other unique challenges faced by the single soldiers. The benefit structure the army provides is geared towards soldiers with families. This is true of other armies around the world. An excellent example was recently reported in Canada. Canada may have a much smaller standing army than the United States, but there too the problem of single soldiers has surfaced in a public and contentious manner. The families of four unmarried soldiers that were killed in Afghanistan stepped forward recently to file human-rights complaints in that country. They say that the government discriminated in favour of married troops by paying a $250,000 death benefit. According to the Canadian Press: A federal human-rights tribunal rejected the complaint of Lincoln and Laurie Dinning because Veterans Affairs abruptly decided to recognize their sons girlfriend as his common-law spouse,

Reflections of Milton in Paradise Lost and On Having Arrived :: comparison compare contrast essays

Reflections of Milton in Paradise Lost and On Having Arrived At a young age, John Milton was convinced that he was destined for greatness. He thought that he "might perhaps leave something so written to aftertimes as they should not willingly let it die"(Text 414). For this reason he thought that his life was very important to himself and to others. He often wrote directly about himself, and he used his life experiences as roots for his literature. In Paradise Lost and in a sonnet entitled "On His Blindness," Milton speaks indirectly and directly of his loss of vision. Also in Paradise Lost, he uses the political situation of his time as a base for the plot, and he incorporates elements of his own character into the character of Satan. In "On Having Arrived at the Age of Twenty-Three", he speaks plainly about the course of his life. In the latter part of his life, Milton lost his vision. This loss was very traumatic for him because he had not yet completed his mission of writing a memorable work of literature. Soon after, he continued his work with the help of his daughters. He dictated to them a sonnet he called "On His Blindness" in which he asks how God expects him to do his work blind. Milton's ambitious side says that his writing talent is "lodged with [him] useless"(Text 417). His religious side soon realizes that he is "complaining" to God and he takes it back. He discovers that God will not look down on him if he does not write a masterpiece. He granted Milton a great talent, and he expects Milton to be happy. He has to learn to do his work in a dark world. This poem was not the last time Milton referred to his condition in his writing. In book one of Paradise Lost, while invoking the Muse, Milton says "what in me is dark illumine"(Hndout 22). He asks to be granted the power to work through his blindness. He obviously thinks of his blindness as a major weakness. Later in the text, he describes Hell as having "no light, but rather darkness visible"(Hndout 270). It is Milton's way of almost subliminally implying that his condition is comparable to

Airstar Case Study

Abstract: Airstar’s organizational design is outdated. Former president and actual president have been managing the company under the assumptions of a predicable environment. Airstar is having problems with communication and job-description along the company. Tasks have been assigned superficially and job responsibilities are not descriptive enough. The cross-functional communications among managers is not working effectively and employees have been working up their own job description. Because of that, goal accomplishment is fast becoming obsolete and decisions are being made on the basis of practicality. Also, the company is facing external threats from major competitor such as General Electric and Pratt & Whitney. The stagnation from top managers is causing chaos internally, because business environment is constantly changing and most managers have been in the company for more than twenty years. So, for maximum efficiency, Airstar needs to guide their employee with standards and written guidelines in order to succeed and move forward. Introduction: Airstar Inc. manufactures, repairs, and overhauls pistons and jet engines for smaller, often previously owned aircraft† (Daft, 2008, p. 84). It has a solid history and its strength comes from the fact that it is well known in the market and employee loyalty. However, the rapidly changing industry parallel with the change in the presidency is causing problematic factors for Airstar. A company that has been in the market for twenty years producing customer and employee loyalty now has threat with new arriving business competition and the ever-changing business environment. Unfortunately, Roy Morgan, the president, assumes that he could continue to run the company as it had been twenty years ago. In the past, decisions had been made on the basis of practicality. However, the current environment is in need of changes in duties and management practices. The lack of ample communication concerning duties and how to restructure them for better efficiency is causing internal chaos. So, communication appears to be the Aquiles problem of Airstar. Problems The first significant issue for Airstar is the threat of the changing environment. As Walmart founder Sam Walton said once that advantage competition is not just continue to develop but to stay ahead of competition and the learning curve of its environment (Walmart, Inc. , 2010). To continue to exist, the organization needs to not merely adjust to, but also to influence the changing environment, and in consequence, creating a company worth for its stakeholders. According to the case study, there is a major lack of leadership and coordination. The second significant issue for Airstar is that the current system is neither cooperative, nor strategic intent. Strategic intent means that â€Å"all the organization’s energies and resources are directed toward a focused, unifying, and compelling overall goal† (Daft, 2008, p. 60). It shows that the values established by the founder were never reviewed for the purpose of internal and external changes. The company vision and mission statement are worthless if there are not communicated throughout the various hierarchies of the company. Also, Airstar current system has shown overlap responsibilities between employees. Specific tasks should be assigned to employees that are better suited for these tasks. Another significant issue for Airstar is the instability of its external environment. This problem could provoke stressed employees and in consequence, a less effective performance (Rolfe, 2005). Managers should not only communicate effectively, but also listen to employees and be responsive of the way they experience different factors within the company. Such consideration will bring better management strategies not only in assigning the most appropriate duties, but also in managing the stress factor related to required structural adjusts. The last significant issue is the threat created by new competitors. Competitors, who are new to the market, will make every effort to follow solid business principles to attract value customers and gain market share. Airstar is no longer the sole service provider of its industry, and finds itself in an environment that is quickly changing. Here is where the mature organization comes to play. Airstar has been known for its safety, superior quality, and customer service. These are strengths that can be hard to conquest and could possibly allocate Airstar ahead of its competitors. Interventions Jim Robinson, vice president of manufacturing, pointed it out six principles that appear to focus on internal changes and could provide Airstar with a better position to handle external environmental changes and a stronger internal structure. First, formalization is lacking because of the long lifetime of the company without written rules and regulations. It is recommended that Airstar begins its internal renovation process by creating a list of recommended rules, regulations, and policies. Second, these initiatives are communicated in writing, so it can provide managers and employees with the opening to comment. Then, after being implemented in writings takes place, meetings could be held to discuss comments. Third, it is recommended that Airstar creates a mission statement, a number of goals for future that relate to it, and strategies to arrive at these goals. Then, after implementing the goals and tasks to achieve internal productivity, Mr. Morgan should assign appropriate personnel members to avoid the overlapping that has been occurred in the past. Furthermore, the external environment requires to be monitored on a frequent basis so that indispensable responses can be implemented in a timely manner. The monitoring procedure can also be allocated to specific personnel members, who should communicate with top managers via meetings. Fifth, the hierarchy of authority should be established and updated according to the variety of tasks and strategies within the company. As Robinson refers, Airstar’s internal structure should be kept to a minimum. It is a sound standard keeping the internal structure of the company as simple as possible in order to center on goals rather than on endeavoring to manage extensive personnel members and their many duties. Conclusion Airstar has proven to retain a quite considerable, although somewhat lesser, customer base. I believe the company has the potential to recover itself with internal structural changes, as recommended above. Mr. Morgan attitude is very optimistic towards implementing adjustments for the benefit of his company. His willingness to hire a consultant and put into operation suggestions shows that he is serious about fetching his company up to date with the external environment. However, it is important that Mr. Morgan and his entire management team do not make these decisions on an isolated foundation, but that employees should be incorporated in implementing some of the changes. References Daft, R. (2008), Organizational Theory and Design, 10th ed. Mason Ohio, South-Western Cengage Learning. Rolfe, Foreman and Tylee, 2005, Welfare or Farewell? Mental Health and Stress in the Work Place†, Issue 268. Retrieved from Academic Search Complete Walmart, Inc. (2010). Walmart Corporate. Retrieved November 16, 2011, from Walmart Annual Report: http://walmartstores. com/sites/annualreport/2010/

Peroxide Definition and Facts

A peroxide is defined as a polyatomic anion with molecular formula O22-. The compounds are generally classed as ionic or covalent or an organic or inorganic. The O-O group is termed the peroxo group or peroxide group. Peroxide also refers to any compound containing the peroxide anion. Examples of Peroxides Hydrogen peroxide, H2O2, is a simple peroxide compound.Other inorganic peroxides (aside from hydrogen peroxide) are known. These are classified as either ionic peroxides or covalent peroxides. Ionic peroxides contain alkali metal ions or alkaline earth ions as their cations. Covalent peroxides include hydrogen peroxide and also peroxymonosulfuric acid (H2SO5).Technically superoxides, ozones, ozonides, and dioxygenyls are peroxide compounds, but they tend to be considered separate because of their special characteristics. Peroxide Occurrence and Uses Peroxides occur naturally in small amounts in plants and animals, water, and the atmosphere. In humans and other animals, hydrogen peroxide is a by-product of biochemical reactions. The chemical is short-lived but is toxic to cells because of its ability to oxidize DNA, proteins, and membrane lipids. This toxicity makes peroxide useful as a disinfectant, to kill bacteria and other pathogens. However, nearly all eukaryotic cells purposely form peroxide in organelles called peroxisomes. Peroxisomes are used for catabolism of fatty acids, D-amino acids, and polyamines and for biosynthesis of compounds essential for normal lung and brain function.The enzyme catalase uses peroxide to oxidize substrates to neutralize toxins in the kidney and liver cells. In this way, for example, humans are able to metabolize ethanol into acetaldehyde.Plants use hydrogen peroxide as a signaling chemical indicating defense against pathogens.Some peroxides can bleach or decolorize organic molecules, so they are added to cleaning agents and hair colorants.Peroxides are widely used to synthesize drugs and other chemicals.The bombardier beetle stores hydroquinone and hydrogen peroxide in abdominal reservoirs. When the beetle is threatened, it mixes the chemicals together, resulting in an exothermic reaction that enables the beetle to squirt boiling-hot, smelly liquid at a threat. Peroxide Safe Handling Most people are familiar with household hydrogen peroxide solution, which is a dilute solution of hydrogen peroxide in water. The type of peroxide sold for disinfecting and cleaning is about 3% peroxide in water. When used to bleach hair, this concentration is called V10. Higher concentrations may be used to bleach hair or for industrial cleaning. While 3% household peroxide is a safe chemical, concentrated peroxide is extremely dangerous! Peroxides are potent oxidizers, capable of causing serious chemical burns. Certain organic peroxides, such as TATP (triacetone triperoxide)Â  and HMTD (Hexamethylene triperoxide diamine), are highly explosive. Its important to understand these highly unstable compounds may be made by accident by mixing together acetone or other ketone solvents with hydrogen peroxide. For this, and other reasons, its unwise to mix peroxides with other chemicals unless you have full knowledge of the resulting reaction. Peroxidic compounds should be stored in opaque containers, in cool, vibration-free locations. Heat and light accelerate chemical reactions with peroxides and should be avoided.