Abstract This paper examines the physiological changes that occur in the body at high altitude, particularly in respect to the heart. The paper examines what happens to the body during short-term exposure and long-term exposure to high altitude, and exposure to extremely high altitudes.
From the Paper "Several circulatory changes mediated by stimulation of the carotid body which causes activation of the sympathetic nervous system are stimulated by short-term altitude exposure less than three or four days. These changes occur within a few minutes of altitude exposure and are related to a transient epinephrine secretion combined with a more sustained secretion of norepinephrine. These cause immediate changes which include an increase in ventilation, increased heart rate, increased cardiac output and an elevation of blood pressure. There is also an increase in coronary blood flow."
Tags: cardiopulmonary, high altitude, acclimatization
Abstract The paper discusses altitude training, which involves exercising and/or living at fixed heights for a length of time, in order to take advantage of the reduced oxygen. The paper examines how this condition is accompanied by other physiological disturbances, including mental toughness. The paper discusses how sports experts and other trained observers suggest that one should take caution about investing a large amount of time,money, and health, in a practice which promises only minimal benefits. The paper concludes that altitude training can decrease performance at sea-level, which would be counter-productive for the athlete.
Outline:
Introduction
Methods
Altitude Training and Effects of the Environment
Physiological Effects
Negative Effects
Conclusion
Bibliography
From the Paper " A number of studies pointed to the value of lower oxygen cost of steady-state cycling and running after exposure to hypoxia as an observed but unexpected benefit of LHTL (McConnell 2006). Saunders and group found the oxygen cost of running was at an average of 3.3% lower after LHTL than after two interventions. Otherwise, there were no significant differences between or within subject groups for ventilation, heart rate, respiratory exchange ratio or hemoglobin mass. The absence of a change in R field likewise appeared to support the contention of improved mechanical efficiency after LHTL, such as increased use of carbohydrate."
Abstract This paper first offers an explanation of high altitude and then goes on to describe the important changes that occur in the internal environment of the human body.
From the Paper "The effects of high altitude on the human body is hypoxia, hyperventilation, changes in lung volume, changes in pulmonary diffusing capacity, changes in number of red blood cells, changes in hemoglobin concentration, and changes in cardiac output. The human body is also prone to high altitude stress which includes effects like increased secretion of ADH, redistribution of body fluids, and impairment of mental reactions. "
Abstract This paper examines acclimatization, the process by which the body adapts to changes in altitude. The body's various physiological responses to acclimatization are discussed, such as increased pulmonary ventilation and the presence of abnormally high numbers of red blood cells in the circulatory system known as polycythemia, among others. The paper concludes with a literature review which cites and analyzes various research studies in acclimatization.
Outline:
Increased Pulmonary Ventilation
Polycythemia
Rightward Shift in the Oxygen Dissociation Curve
Changes in Capillarization
Changes in Oxidative Enzymes Within Cells
References
From the Paper " Increased resting and submaximal ventilation is observed in immediate response to altitude related hypoxia (Wyatt, 2002). This increased ventilation is achieved through increased volume and rate of breaths, and individual variation in hypoxic ventilatory response has been demonstrated (Wyatt, 2002). Research has shown that individuals with strong hypoxic ventilatory drives exhibit better performance at high altitudes than individuals with less efficient drives (Wyatt, 2002). The stimulated ventilation that results from exposure to high altitudes is due to aortic and carotid sensitivity to reduced PO2 in arterial blood. This increase in ventilation increases PO2 in the alveoli and reduces end-tidal partial pressure of carbon dioxide (PETCO2), which lends to reduced carbon dioxide and H+ in the blood. In response to these reductions during the initial few days of exposure to altitude, the kidneys gradually excrete bicarbonate (HCO3), which is associated with decreased plasma volume. Increased pulmonary ventilation also results in a reduction in total water in the body due to loss of water vapor that occurs during respiration, which results in rapid dehydration during acute altitude exposure (Wyatt, 2002)."
Effects of high altitude on athletic performance. Looks at how it effects their training needs, oxygen use & availability, endurance and the dangers involved.
2,025 words (approx. 8.1 pages), 8 sources, 1997, $ 71.95
From the Paper " Altitude and its effects on athletic performance will be discussed with regard to the following subtopics: adaptations the body makes as a person goes from sea level to a high altitude; changes brought about by aerobic compared to anaerobic exercises at high altitude; and the effects, positive or negative, of training at altitude. A drastic case study will be cited to demonstrate the magnitude of the effect of altitude change on physiology.
At altitudes of over 5,000 feet, the ability to perform physical work is affected--the higher the altitude, the more severe the effects. In general, one can expect a reduction in endurance capacity as measured by the maximal oxygen consumption of 3 to 3.5 percent for every 1,000 feet ascended above 5,000 feet. Work performance and maximum oxygen consumption are..."
Abstract This report details some of the more common vegetation found in Nicaragua, from the rainforests of the Caribbean coast to the Mangrove forests of the pacific coast. Nicaragua is so diverse in vegetation that it seems like you are in a completely different place from one region to the next.
Introduction
Rainforests
Mangrove Forests
Dry Tropical Forests
Pine Savannas
From the Paper "The rainforests of Nicaragua are the most diversified forests in Central America. The eco-region is made up of lush, tall forests of trees reaching over 150 feet in height, with a diversity of palms and other smaller trees in the understory. A total of 65 varieties have been identified as commercially valuable, but some of these are more valuable than others. For example, Mahogany is one of the tallest trees in the Nicaraguan rainforest, its umbrella-shaped crown reaching to over 200 feet high and emerging above the surrounding canopy. Throughout its natural range, from Mexico to Brazil and Bolivia, mahogany has been highly exploited, and today the species is threatened not only by outright elimination, but also by genetic degradation, after centuries of having the largest most robust individuals harvested. In addition, as with many tropical trees, mahogany occurs at a very low density in the rainforest, with mature trees rarely averaging more than one per hectare. Mahogany also has a low rate of natural regeneration, requiring from 60-100 years to reach maturity."
Abstract This paper presents the causes and effects of air pollution. Other stratospheric research is concerned with the downward trends in global ozone that have recently been measured over populated regions in the mid altitudes. The author focuses on the various factors associated with global warming.
From the Paper "Air pollution is any visible or invisible substance found in the air that is not part of the normal composition of air. Some air pollution is natural and has always been a part of the earth's history. However, over the past one hundred years or so, pollution created by humans has become a major environmental problem. Natural air pollution has been around for millions of year. Dust and a variety of gases from forest fires, volcanoes, and decaying material in rivers, oceans, and other bodies of water continually enter the atmosphere. Sometimes this natural pollution can have dramatic effects. Air pollution is a major factor in causing humans to get ill. Tuberculosis, bronchitis, heart and chest diseases, stomach disorders, asthma and cancers can all be traced to chemicals in the air. Pesticides and fertilizers release gases and particles into the air which poison people and kill animals."
Tags: ozone, stratosphere, carbon, environmental, dioxide, sulphur, cfc, deforestation, lead
This paper discusses environmental physiology: Negative effects of high altitude, diving and extreme temperatures, oxygen deprivation, acclimatization, endurance, shock, decompression and precautions.
2,475 words (approx. 9.9 pages), 11 sources, 1994, $ 87.95
From the Paper "Normal physiologic function depends on the maintenance of a uniform internal environment. This is achieved through a variety of adaptive mechanisms which enable the body to respond to changes in the external environment. Adaptive phenomena become most evident in environmental extremes. Three such situations include high altitude, diving, and extremes of temperature. These adverse conditions test the body's ability to maintain its independence from continuous changes in the external world.
At high elevations, barometric pressure is markedly decreased (5:462). This is due to the fact that the weight of the atmosphere is considerably less than at sea level. One result of the decreased barometric pressure is fewer oxygen molecules per unit volume. This lower oxygen partial pressure (PO2) is the primary factor ... "
An examination of how the Nazis did horrendous and unspeakable experiments on their prisoners for the sole purpose of advancing medical technology of their SS military.
Abstract This paper looks at how the Holocaust killed millions of Jews, Gypsies, and other ethnicities that didn?t fit the description of the super-race and how only the blond-haired, blue-eyed Aryans were accepted under Hitler's order of ethnic cleansing. It examines how one of Adolf Hitler's orders as leader of all Germany was to corral a large group of Jewish, Gypsy, and Russian prisoners on several different occasions and perform experiments on them as if they were animals or worse. It shows how prisoners were forced into deadly tests for the sole purpose of providing research information for the future technology and training of the Nazi military and how experiments were performed on the basis of high altitudes, extreme temperatures, disease, infection, genetics, battle wounds, and fertility.
From the Paper "The freezing experiments performed by the SS doctors were just as disturbing as any other experiment. Men were strapped down to stretchers and lowered in large tubs of ice water or stuck outside in negative-degree weather. They were left until their body was at its limit, and then brought back inside. The experimentation began with the method of reheating the prisoners? bodies. Some were injected with boiling water into their veins. Most died after their internal organs melted over. Some were placed into warm baths and the temperatures were slowly increased. This seemed to be the most successful, though some died of shock if the temperature increased too rapidly."
This paper investigates the use of radio altimeters as part of ground proximity warning systems (GPWS) and the way these devices can help avoid controlled flight into terrain (CFIT) incidents, approach, and landing accidents (ALA).
Abstract This paper explains that the air travel industry is built on principles which maintain its safety records, including multiple redundant systems, and the ability of the pilot and crew to override the systems if they malfunction. The author points out that ?Controlled Flight Into Terrain (CFIT)? is responsible for more than half of all commercial aviation fatalities, making it one of the international aviation community's most pressing safety problems. The paper concludes by proposing a study comparing the accident rate of aircraft with EGPWS systems installed, aircraft with GPWS installed, and aircraft with neither installed.
Table of Contents
Introduction
Literature Review
Controlled Flight into Terrain
Approach and Landing Accidents
Advancements in the GPWS Systems
Minimum Safe Altitude Warning System (MSWA)
Methods and Procedure for the Study
From the Paper "Non-precision approaches increase levels of risk ?significantly,? said Khatwa. The danger is even higher when pilots have a low exposure to such events. Assuming that accident characteristics can be observed in everyday conditions, the research went on to study correlations between ALAs and data from regular aircraft operations. In addition to the 4,000 normal flights, they considered almost 300 worldwide ALAs, as well as other incidents, using International Civil Aviation Organization statistics. Some 287 fatal ALAs from 1980 to 1996 represented an annual incidence of about 17 events. The researched projected that with increasing levels of air travel, ALA incidents were likely to rise to 23 a year. About 50 percent of all accidents are ALAs, and the most dominant circumstance was controlled flight into terrain (CFIT). Almost 75 percent of ALAs involved approaches to airports with no glide slope."
Abstract This paper explains that Iranian population continues to increase at a rapid rate because of the establishment of public health preventive services, which have significantly reduced maternal mortality and raised life expectancy at birth. The author points out that, as the population increases wildly, Iran fails to address its environmental crises and now faces deforestation and desertification of its arid areas, over-fishing of lakes and rivers, industrial and urban waste, continued destruction of wetlands and reservoirs and pollution of the Persian and Caspian Seas by spilling chemicals and oils into them. The paper states that Iran must phase out leaded gasoline, require its people to use catalytic converters, assume a serious long-term approach in environmental protection and focus their direction on developing gas fields and reducing dependence on oil, not only to reduce pollution but also to diversify and strengthen its economy.
From the Paper "Poisonous carbon emissions in Iran have steadily increased in the last two decades by 240% since 1980 or from 33.1 million metric tons in 1980 to 80.8 million metric tons in 2000. The uncontrollable growth of the population has clearly meant an increased and constantly increasing number of cars. The volume of automobile exhaust in Iran alone constitutes 1.3% of the world's total of carbon emissions. While Iran's carbon emissions are lower compared with those in the United States and other industrialized or developed countries, its rampant use of leaded gasoline and the volume of cars without catalytic converters account for the massive levels of carbon monoxide in Iran's urban areas."
Abstract This paper explains that numerous factors account for variations of global patterns of carbon accumulation. The author points out that some of these factors are climate, precipitation, cultivation, degree of irrigation,and altitude. The paper relates that also very significant, especially for tropical and temperate forests, are the measurement standards applied.
From the Paper "Numerous factors account for variations of global patterns of carbon accumulation. Among those factors are climate, soil texture, soil cultivation, amount of nitrogen in soils, and the interaction of altitude and precipitation. Also very significant especially for tropical and temperate forests are the standards applied; not only do these studies use differing measurements depending on the ecosystem, but variations in measurements must often be used within a single ecosystem because of forest floor diversity (Schlesinger, 1977). One factor is geomorphological and/or hydrological instability in swamp and marsh, especially when edged by tree growth."
Abstract The paper describes "The Conquest of Everest" that tells the story of two men who reached the top of Mount Everest in 1953, the first men to reach the summit of the world's tallest mountain. The paper looks at how Sir John Hunt shows the difficulty of preparing for an expedition of this kind and the grave dangers the climbers faced. The paper recommends this book to anyone who is interested in adventure or history.
From the Paper "Author Hunt chronicles the 1953 expedition thoroughly, from the preparations the team made before the expedition, to the studies and attempts made by other teams trying to scale the mountain. He also discusses the problems with climbing the mountain, which now do not seem as difficult as they were over 50 years ago. For example, he writes, "These two factors, the altitude and the weather, tend separately and together to defeat the climber" (Hunt 12). However, today, it is not unusual for many parties to attempt to climb and conquer Mt. Everest every climbing season, and while there are still injuries and deaths on the mountain, equipment, and knowledge have helped create more opportunities for more people to climb the mountain than ever before, so some of these problems have at least been tamed."
Abstract The paper describes the technological progress in aviation that was encouraged by both world wars. The paper then looks at the jet aircraft developed by the United States and the Soviet Union as a result of the Cold War. The paper points out that despite the underlying hostile motivations for its accelerated development, modern aviation has many positive humanitarian benefits.
Outline:
Background and History
The First Generation of Powered Aircraft
The Birth of Modern Aviation
Aviation in the Jet Age
Conclusion
From the Paper "The Wright brothers achieved the first powered flight in 1903, with a 59-second flight that covered a modest 852 feet at an altitude of 10 feet (SASM, 2007). Within little more than a decade from this most humble of beginnings, powered aircraft flight evolved sufficiently for pilots to face each other in aerial combat to the death in the first generation of military combat aircraft featuring full-sized machine guns in World War I. By the end of the war in 1918, bombers capable of dropping nearly 2000 pounds of explosive ordinance were in use by the British and German force(Jackson, 2003)."
Abstract The paper defines VO2 max, giving a clear explanation of the term. The paper demonstrates that the literature associated with VO2 max, in the peer reviewed press and the popular sports and fitness literature and e-information states that the limiting factor of VO2 max in any individual is cardiopulmonary function. If cardiopulmonary function is impaired due to illness, disease, lack of overall fitness, genetics or altitude, the VO2 max measurement will be skewed. The paper argues that this work is demonstrative of the fact that all exercise/training programs should be done only after the clearance of such a program by a trained physician. The paper also argues for the utilization of VO2 max testing in medicine,before the onset of a strenuous physical training regimen. The paper includes figures and a table.
From the Paper "Currently in the medical arena, VO2 Max testing often called cardiac stress testing is done under controlled circumstances on patients who have a known cardiopulmonary function issues, but is only rarely done on healthy individuals in the younger populations. ("Health Matters: Angina Drug," 2005, p. 4) Yet, in many cases those are the people most likely to begin regimens of serious physical training. The current trend of older individuals seeking to become more physically active and also competitive in sports has also increased the numbers of people exposed to VO2 max testing, as many are seeking trainers to help them develop essential endurance they feel they may have lost due to age, and as a result of the fact that they tend to have more expendable income to hire professionals to assist them with fitness goals. This trend of increased VO2 max testing is fundamentally good, if such testing is conducted under the best conditions and if results are utilized as a part of the whole fitness picture, i.e. in conjunction with other tests and measures."
