The Story of Her Life

A deaf and blind girl born in 1880 said, â€Å"Everything has its wonders, even darkness and silence, and I learn whatever state I am in, therein to be content.†Thus, this individual with incapability played and enjoyed her life amid the lack of two senses—ability to hear and see—was able to receive praises and admirations from the people around her. In addition, she was able to contribute to the world important things that even people with senses could not be able to give.The beginning of her lifeAs accounted by the Royal National Institute of Blind People (RNIB), it was on June 27, 1880 when Helen Adams Keller, the daughter of Captain Arthur Henley Keller and Kate Adams Keller, got her first glimpse into the world. She was born healthy—with full ability to hear and see—in Tuscumbia, Alabama in the United States.Based on her writing â€Å"The Story of My Life,† Helen at the age of six months could whistle out the words â€Å"How d’ye † followed by the word â€Å"Tea†. She, like any other normal child, was fascinated with the beauty of the surroundings—its colors and the things composing it.She insisted on imitating whatever people around her were doing. Likewise, she enjoyed the music produced by the natural world and the noise by other people. She could learn whatever the child of her age could learn. Helen started to walk a day before she celebrated her first birthday (6).Nonetheless, unlike the other children, her happy days, manifested by her experiences of being able to see and hear, did not last long. The life of the healthy Keller baby, as claimed by RNIB, changed dramatically in February 1882. Helen fell ill with a disease by which the doctor during that time had named as brain fever—an illness which was also assumed to have been a scarlet fever or meningitis.This illness is still a mystery for the medical doctors of today. The sickness of Helen had led the Keller family in bel ieving that their daughter will die. When, eventually, the fever subsided, made the family rejoiced on the possibility that Helen will become well again.After the fever has passed, however, Helen’s mother noticed the changes in her daughter’s behaviors—Helen was failing to react whenever she passed her hand in front of her eyes or she was failing to hear and to respond whenever the dinner bell was rang. Later they realized that the fever—the illness that struck Helen—had left her both blind and deaf.On her account on her life, she mentioned, â€Å"Then, in the dreary month of February, came the illness which closed my eyes and ears and plunged me into the unconsciousness of a new-born baby.†(7) In the young mind of Helen, she realized that something was being taken away from her—her ability to see the colors and hear the noise, again.This discovery gave the family much worry especially during the following years when taking care of He len proved to be very hard for them. She became uncontrollable—her attitude and behavior became reasons for her relatives to regard her as a monster and a bad member of the family. This made them thought that the young Helen should be put into an institution capable of handling a child with such behaviors. When Helen reached the age of six, the family became more problematic on handling her.Though succumbed in the sad situation, the young Helen was been took care of by her mother. As she accounted, her mother gave her a loving wisdom that was bright and good during when she experienced long night. She began to learn some patterns like when to say â€Å"No† or â€Å"Go away.† At the age of five she learned more things beyond the things that she could see and hear.Based on the accounts of RNIB, Kate Keller, Helen’s mother had read a book by Charles Dickens entitled â€Å"American Notes† which entailed the fantastic work done to another deaf and blind child named Laura Bridgman. Because of her love to her daughter, she travelled to a specialist doctor in Baltimore to seek for advice in regards to the situation of Helen—later she learned that Helen would never see and hear again. However, the child could learned and be taught.They were advised to see an expert on the problems regarding deaf children—Alexander Graham Bell, the inventor of the telephone. Graham Bell pointed that they should write to the director of Perkins Institution and Massachusetts Asylum for the Blind, Michael Anagnos, and asked for a mentor that would guide and teach the deaf and the blind child. Convinced with the hopes and possibilities that Helen would learn, Michael Anagnos, recommended Anne Sullivan, the Institution’s former student, to be the tutor of Helen.

Env410 Toxicology Worksheet

University of Phoenix Material Toxicology Worksheet 1. Identify the different resources available for your learning in this course. Available resources during this course includes two textbooks; â€Å"Introduction to ecotoxicology,† and â€Å"A textbook of modern toxicology. † Additional resources include various videos, complimentary transcripts to the videos, supplemental readings, the UOP online Library, and web searches. 2. Define toxicology.Toxicology is defined as that branch of science dealing with poisons. According to Hodgson (2010), a â€Å"poison can be defined as any substance that causes a harmful effect when administered, either by accident or by design, to a living organism† (p. 3). Toxicology also includes the study of harmful effects caused by physical phenomena, such as radiation of various kinds, noise,† and â€Å"the study of the detection, occurrence, properties, effects, and regulation of toxic substances,† (Hodgson, 2010, p. 3) .Rarely defined as a single molecular event, toxicity involves a cascade of events, which start with exposure, and proceeds through distribution and metabolism, and ends with the interaction of cellular macromolecules (such as DNA, or protein) and the expression of a toxic endpoint (Hodgson, 2010). 3. Define environmental toxicology. According to Hodgson (2010), environmental toxicology evaluates the movement of toxicants and their metabolites and degradation products in the environment and in food chains, and with the effect of such contaminants on individuals and, especially, populations† (p. ). A specific area of environmental toxicology dealing with the work environment is industrial toxicology (Hodgson, 2010). 4. What is the difference between environmental toxicology and ecotoxicology? The difference between environmental toxicology and ecotoxicology is that the latter integrates the effects of stressors across all levels of biological organization from the molecular, to whole communities and ecosystems. In contrast, environmental toxicology focuses upon environmental toxic effects (Silverstars, 2010). 5.What knowledge can be gained from dose-response relationships? Dose-response relationships are used to determine a dose-response curve, which quantifies the acute toxicity of a chemical. Dose-response relationships are established by comparing the dose of the administered chemical and the resulting response of the organism. Affects are recorded at defined periods of time after dosing occurs. A dose-response curve is a result of the plotted results, creating various segments. Segment I, has no slope and represents doses of the toxicant that do not evoke mortality.Segment II, represents the doses that affect only the most susceptible members of the exposed population, generally a small percentage. Segment III, reflects the doses at which the majority of the population eliciting some response to the toxicant, and is the steepest slope of all segments. Segment IV, identifies the doses of the toxicant that are toxic to even the most tolerant organisms of the population, which are generally high doses of the toxicant. Segment V, represents the doses at which all of the exposed organisms are affected, and has no slope (Hodgson, 2010).The LD50 of the toxicant is determined by using a well-defined dose-response data, logarithms and percentage effect to determine the probable units. 6. Why are the shape and slope of a dose-response curve important? The shape and slope of a dose-response curve is important because the dose-response curves are used to derive dose estimates of chemical substances. The slope of the linearized data set from a dose-response curve provides information on the specificity of the toxicant. Steep slope elicit toxicity, whereas, shallow slopes elicit nonspecific toxicity.The dose-response line also allows one to estimate the threshold dose, by defining the lowest dose expected to elicit a response. The threshold d ose is one that is lower than the greatest dose at which no affect is detected. This is generally between segments I and II (Hodgson, 2010). 7. What role do they play in environmental toxicology? This helps put toxins into exposure classes. This allows scientist to determine what level the toxins are lethal, or what levels may help prevent undesired medical conditions, such as cancer.These levels are used for regulatory purposes as well, to minimize exposure to harmful toxins and their effects on human health and the environment (Hodgson, 2010). 8. Explain LD50. LD50 refers to the dose level (concentration level) of a toxic substance (poison) required to obtain a lethal dose that kills 50% of a population under stated conditions, such as the controlled variables of the study. This level is typically normalized to the weight of the animal (milligram chemical/kilogram body weight), and the measure of acute toxicity is used to assign of toxicity to the given chemical (Hodgson, 2010). 9 . Explain LD10.LD10 refers to the dose level (concentration level) of a toxic substance (poison) required to obtain a lethal dose that kills 10% of a population under stated conditions, such as the controlled variables of the study. This level is also typically normalized to the weight of the animal (milligram chemical/kilogram body weight), and the measure of acute toxicity is used to assign of toxicity to the given chemical (Hodgson, 2010). Review the following chart and answer the following questions: Based on LD10, which toxicant is more potent? Why? Based on LD10, toxicant B is more potent because the death rate of 70% is higher than 60%.Based on LD50, which toxicant is more potent? Why? Based on LD50, toxicant B is more potent because the death rate of 85% is higher than 70%. At what dose do these toxicants have the same percentage lethality? The dose at which these toxicants have the same percentage of lethality is 0. 5mg because that dose puts the death rate for both Toxican t A and Toxicant B at 40%. Toxicology Chart DoseToxicant AToxicant B mg/kg% lethality% lethality 0. 012025 0. 052530 0. 13035 0. 54040 14550 55565 106070 507085 1007595 50095105 1,000100107 5,000105108 10,000107109