How Is Tension Created And Maintained Between John And Elizabeth, And How Does Their Relationship Change?

Arthur milling machine was born in the socio-economic class 1915 and grew up during the dandy depression. His fathers business crashed during the great depression, this meant there was no money for Arthur miller to knock his great talent that was exercise writing. Fortunately through earning small amounts from funny jobs he was able to ease up enough to go to university where he received several awards for his early plays. Arthur Miller wrote The melting pot in the year 1952. He used the play as a focus of criticizing the disposal for what is k right away as McCarthyism. McCarthyism is a communist beguile hunt where anybody could be charge of being communist.One of the many an separate(prenominal) people to be accused was Arthur Miller this is why the main themes of the play are justice and truth. Arthur Miller normally uses society and individuals as main themes for his plays this lavatory also be seen in the crucible. A good example of this is how all the other members of the puritan community look d avouch on rear end watch over for non being a regular church-goer. This is relevant to mean solar day because it could be translated into a suppression of individuality and a pressure for people to fit into society. another(prenominal) area it explores is the increase of stress and panic in a society.The Crucible is set in a small puritan town where everybody knew each other and it was a very tight community. The despised local sermoniser called Parris stumbles across several of the villages girls performing a sinful dance including his own daughter Betty. While the girls are performing the dance with his slave Tituba , Betty locomote into an unconscious state causing panic. The girls are accused of witch craft. The girls defy to this but one of the girls called Abigail who had an affair with one of the central characters called tin Procter sees a chance to exploit the situation and claims there are much witches in the village.Abigail s trou gh has feelings for tush claims that his wife Elizabeth is a witch. sewer goes to judicial system to compendium against this, he also shows the court about the affair he had with Abigail to burst her credibility. The court gets Elizabeth to pose in and confirm bums confessions but unfortunately she denies it to birth his reputation. toilet is sentenced to be hung Elizabeth who has survived so far due to her pregnancy tries to incite trick to confess to witchcraft point he chooses to die with his hauteur rather so live without it.The Salem witch trails was a certain event and conjuring trick , Abigail , Elizabeth and some other characters were real people hitherto a lot of the story was written by Arthur Miller. The language of the play is accurate because it uses the correct accents and the characters would boast been played by English actors because the moderne Ameri advise accent would not have developed yet. To show the circumstance that the characters live in a very religious community the characters a great deal make references to the Bible this behind be seen were Elizabeth describes Abigails affect on the court as Parting the sea of Israel. This shows that the bible was part of their every day behavior. Before Act two starts the earshot is aware of the tension amid John and Elizabeth because of Johns affair with Abigail. patronage having an affair with Abigail John still chouses his wife and pauperizations to protect her. A good example of this is were Abigail accuses Elizabeth of being sickly and John says You leave say nothing of Elizabeth. Which show he requirements to protect her oer Abigail . The tone he uses is angry and full of frustration which shows that he is spoil and ashamed for having an affair.Read also Intro to Public Relations NotesThe background signal of the scene makes the audience question Johns commitment to Elizabeth , the scene is set 8 days after Abigail told John that her actions are nothing to do with bring out that in fact there are no witches in the village and they where just dancing sinfully. This show that John is withholding information from Elizabeth and the symmetry of the community and the audience is aware of this. The room that the scene is set in is described as long, dark with a low ceiling which could be a metaphor for John and Elizabeths birth.It is also set in this way to create pressure and claustrophobia in the scene ahead which adds to the tension. In demarcation line to this Elizabeth can be heard singing to the her children which paints a picture of a loving mother in the audiences minds and can create a genius of empathy with the character. It also demotes the impression that John and Elizabeth where once a loving couple. The blueprint of speech used by the characters increase the sense of tension because it is in short sharp snippets spoken rushed as if not to fracture one another by singing to long.It is clear that Elizabeth concerned w hy John is late and she decides to confront him about. She expresses her worry by saying You come so late I thought youd gone to Salem this afternoon. John lies and says Why I have no business in Salem. Which the audience dos is un consecutive(a) because he was previously in Salem where he met Abigail, this shows that John feels he has to lie to Elizabeth and that it is easier then telling the truth. John then checks the bulk large and is displeased with its taste so he proceeds to add more seasoning.When he is served the stew and tasted it he compliments Elizabeth on the seasoning. These shows how troubled their relationship is because John would rather lie about the seasoning of the stew then tell her it was under seasoned. The couple begin to discuss the witch trials and Elizabeth asks John to go to court and explain to the court about Abigails trickery. John dismisses this and says things bid Ill think on it. And the stage actions show him considering where or not to tell the court.Elizabeth thinks he is trying to protect Abigail but really he doesnt want Elizabeth and himself to be accused of witchcraft. The couple begin to argue and use longstanding sentences to express their true feelings which break the tension that has been built up through out the scene. In this scene the couple are trying to fend off confrontation or trying to please one another we can see this from the stage directions where it says Holding back a full expletive of her and She doesnt want friction. Act three is the most important scene involving John and Elizabeth.John has gone to the court to confess about his affair with Abigail which leave alone discredited her and certify her accusations of witch craft false. To prove Johns confession true Danforth the judge asks Elizabeth to be brought in the first place the court who John claims can neer tell a lie. This increase tension because if Elizabeth does lie it will worsened because John has put all his trust in Elizab eths confession. When Elizabeth goes into the room John and Abigails backs are turned, this is so they cant give hints to Elizabeth but it also is a jibe how Elizabeth is feeling about the two.She thinks that John has turned his back on her. The tension is enhanced by Arthur Miller gives stage direction She glances at Proctor for a clue. and She turns to Abigail. This shows how Elizabeth is trouble over making the right decision. When she finally answers we can see that she is still trouble at her decision (in agony) No sir. With this Elizabeth has condemned many people however she has realized that she still loves John and will even lie ,something that goes completely against her beliefs to save his reputation. It also shows that Elizabeth is not perfect and has begun to exempt John.In the next scene John is about to be hung however Elizabeth has a chance to convince him to confess which will save his life but ruin his reputation. This instantly creates tension because it gives Elizabeth a chance to save John. The audience wants to see Elizabeth ask John to lie and confess to witch craft but the tension is prolonged because Elizabeth fails to give John a final answer. She puts the decision in his hands by saying do as you will. John wants Elizabeth to be part of the decision because he says would you give them such a lie. Showing that John respects her feelings and considers her to be his collaborator raising the tension even more because of the couples new found supervise for each other. We finally see her true feelings where she tells him and yet youve not confessed till now. That speaks goodness in you. and if she does not give an answer John will continue to deny the charges building more tension because the audience now fears for Johns life. John and Elizabeths relationship is still getting better however John still thinks of himself as a fraud and a no good man.Elizabeth doesnt want John to think this , this is made clear where she says Do as yo u will, do as you will. Which shows that she is giving him space so that he can prove to himself that he is a good man. John decides against confessing and by doing so he now feels he is worthy of Elizabeth. Elizabeth finally forgives John telling him her true feelings John I counted myself so poorly made, no honest love could come to me Suspicion kissed you when I did I never knew how to say my love. It was a cold house I kept. This also shows that she has recognised her own failings.Despite the fact that John is going to hang the audience now know they both recognise their love for each over which is signified by Johns kiss he lifts her, and kisses her now with great passion. Showing they are not afraid to love each other. The play shows us that it is atrocious not to speak your mind and that it can lead to great tragedies. It is also dangerous for society to put someone in a position where they cannot speak their mind. John and Elizabeth realized this and if they had talked a bout their feelings more then Elizabeth would not have had to of lied.We can also see the parallels the play shares with the McCarthy communist hunt. The death at the end is important because it was preventable the play also shows how lies and deceit can lead to pointless deaths. We can also see the pressure needed for people to talk about there true feelings , only when John was about to hang did the pair express their love for each other and in contrast to this when they where living a comfortable life before the trials they where constantly wanting to please one another and not break up their normal everyday existence.

Essay Childhood Obesity Essay

Childhood Obesity is a health issue, fix by having excess body weight as well as excess of body fat. This is a thoughtful problem for the future of beau monde especially now that our children are not getting enough somatogenetic activities because of technology and unhealthy eating patterns. Children who are obese are believably to be obese as adults. Therefore, this habits can take our children to have serious health problems such as heart disease, diabetes, stroke, high cholesterol, and many others health problems. The environment in which we live is been also part of this problem. Children are ring by unhealthy commercials and bad influence from their parents.Beverages like sodas which contains approximately four hundred calories, and unhealthy choices of meals have contributed to this epidemic cause. Leading our children by giving them examples of how to clog this kind of problems could be a solution for a better life style and future. It is important that parents suppor t their children by serve welling them do a food and physical activities. If your child look at you as a broad(a) example of how to tour healthy, they are more likely to be and stay active for their own. Instead of leaving them playing video games, take them to the putting surface and have fun. Being able to spend more time with your kids and be part of their life, can take them to be better not provided mentally, but physically.Childhood obesity is been an enormous problem for our society. Furthermore, it is our responsibility to help the future generations by giving them a good example of financial support and love for those who needs the most.Web, www.obesityaction.org, www.healthychildren.org

Online Financial Service Provision in Saudi Arabia

Furst, Lang & Nolle (2000) write that the Internet has been viewed as a valuable shaft of light by bankers as well as lawmakers, early(a) participants in the fiscal services industry in addition to regulators and business journalists around the world.As financial institutions do away with paperwork and cut costs of employing clerks to handle paper proceeding in conventional financial companies customers lives are made easier as they do not have to visit their financial institutions to carry out necessity transactions (Furst, Lang & Nolle, p. 1). Saving time equates to saving money in this scenario. Thus, the entire economy benefits through greater efficiency of financial institutions when they blunt up their virtual branches on the World Wide Web.How has the Saudi Arabian financial industry benefited from the advent of the Internet? Are their factors that especially delay or support growth of online provision of financial services in Saudi Arabia? How does e-commerce inf luence growth of online financial service provision crossways Saudi Arabia?In order to answer these questions, my dissertation entitled, A breeding of Factors Influencing Growth of Online Financial Service Provision in Saudi Arabia would necessitate me to conduct online interviews with managers of major and minor financial institutions in Saudi Arabia. This look for would explore factors influencing growth of Internet banking in addition to online provision of other financial services, for example, insurance in Saudi Arabia.Furthermore, this study would determine whether there are differences between Islamic and non-Islamic financial institutions as far as online financial service provision is concerned. Lastly, this research would explore the target commercialise for online financial service provision in Saudi Arabia, with the aim to give away customer profiles, taking gender into account.REFERENCESFurst, K, Lang, WW & Nolle, DE 2000, Internet Banking Developments and Pro spects,Economic and polity Analysis Working Paper 2000-9, Sep 2000. http//www.occ.treas.gov/ftp/workpaper/wp2000-9.pdf. 

Margaret Laurence’s The Stone Angel Essay

Marg aret Laurences The endocarp backer is a invention, which depicts the expiry days of life story of the protagonist Hagar Currie-Shipley. overcharge, loneliness and lowest journey to conclusion are the principal(prenominal) themes of the novel.  The calibre of Hagar is transformed through and through the novel and the readers dejection see distinguishable stages this old char comes in her perception of other people, life and death. Multiple flashbacks give us root word about the life of the main character and people who surround her. Margaret Laurence goes nevertheless than mere description of events. Deep investigation of Hagars be lie downfs, thoughts and ideas present not only a valuable investigation of old ladys inner world, but similarly thrust the readers to reflect on such important themes as love, friendship, pride, acceptance of death and coming in foothold with ones reality.Margaret Laurence wrote in one of her interviews that she was not undi sputable if the rifle days of ninety-year old woman could be an interesting reading for the child corresponding audience. But she dared and fulfilled her idea and the novel became popular among the readers. It was included into some(prenominal)(prenominal) study courses soon after it was published. The subject touched in the novel echoed in the hearts of the readers and they were ready to share an recognize of dying woman and reflect on the themes of pride and loneliness.Pride is the best characteristic of the main character. All Hagars life is dedicated to one ultimate use she wants to make a practiced appearance by both means. some(prenominal) manifestations of emotions she regards as weakness, which should be avoided by either means. The name of the novel set outs a symbol for this pride, which makes the main purpose of Hagars life. From proto(prenominal) age she feels ranking(a) to other children. An mishap on the Manawak underprice is re tout ensembley character istics for better taking into custody of Hagars character.When Hagars friend Lottie killes sm all told chicks in the Manawak dump Hagar becomes largely impressed by this accident. This accident made such a great impression on Hagar that she was not able to forget about it during all her life. Many years later she retold this accident to Lottie after the death of their children. This accident had such an impression on Hagar not only because of her extra sensitiveness. For her putting to death birds became manifestation of strength. This strength was manifested by her shy friend.As Hagar herself describes her Lottie was light as an eggshell herself, and I felt surly toward her littleness and pale picturesque hair, for I was tall and sturdy and dark and would have comparabled to be the opposite (Laurence,. 27). Comparing herself to Lottie Hagar suddenly came to realization that she was weaker than slim and shy girl she disdained. This accident became one of the turning points in t he becoming of Hagars temperament and shaped out all her further life. An accident in the Manawak dump made Hagar obsessed with pride and thirst to keep a high-priced appearance in front of people by any mean. Pride became sense of life and she was ready to sacrifice everything to this ideal. She did not make any exceptions, even for her well(p)est people.Being unnerved to become weak, she even refuses to piss being her mother when her dying brother asks her about this. She refuses to do so because she believes her mother was a weak per male child and Hagar is afraid even to ready being weak. Pride does not let Hagar to accept the choice of her son to marry Lotties daughter. She sees their relations as a joke of beau ideal if people had told me forty years ago my son would fall for No-Name Lottie Driesers daughter, Id have laughed in their faces (Laurence, 204). She boldly takes Gods challenges and decides to destroy their relationships. For this purposes she even turns to Lotties help. Hagar is stubborn and self-assured enough to make the decisions for other people and their future.She does not take nips of other people poorly and even happiness of her own son does not count in comparison to her own ambitions. She does not hesitate even for a subtile when making a decision to destroy Johns and Arlenes relationship. Hagar forgets her own youth when she did not listen to anybody and married the man she had fall in love with. I saw them with a covey of young, same(p) Jesss had been, clustered resembling fish spawn, children with running noses and drooping, handed-down pant four sizes too large. I couldnt face the thought. (Laurence, 211) She is absolutely sure in her right and power to decide the destinies of other people and such spatial relation ultimately results in a tragedy. Pride and aesthetic feeling become main reasons, which define all Hagars behavior.Obsession with the immenseness of appearance becomes a reason, which destructs Hagars life. This concern about appearance prevented her from enjoying physiologic love with the husband. Inner rules and restrictions did not let her to forget about moral philosophy and appearance even for a minute. Doing her best to keep a computable appearance she does not even cry on the funerals of her beloved son. final stage is another important theme of the novel. All Hagars life becomes a constant battle with death. Since early years she denies death and destructions and since these very early times they follow her step by step. Feeling an approach of death, Hagar tries to nonpayment this reality and looks for the mean to deceive death. In the beginning she turns to memories and recollects the pictures from her past. Childhood memories, spousal relationship and children, all these memories help Hagar to create her own reality where there is no place for death. She throw out not even tolerate thoughts about death.In her reflections she states Hard to imagine a world and I n ot in it. Will everything stop when I do? Stupid old baggage, who do you think you are? Hagar. Theres no one else like me in this world (Laurence, 255). Such a position reflects selfish attitude and pride. Hagar can not believe that the world can exist without her.  When Hagar realizes that she can not escape from reality any more aggression and desire to change something replaces all other feelings. Hagar rejects help of other people and tries to appointment death. She can hardly control her feelings and anger becomes a mean to elicit her protest against the existing order of the world. The realization become difficult because death is that phenomenon, which Hagar tried to escape by any means since early childhood.From the very moment when Lottie killed chicks Hagar did not want to confess even to herself that death was a natural part of the world. She rejects any kind of help and digs Marvins take in charge to put her in the nursing home as a humiliation. unaccompanied af ter long period of inner fight Hagar at long last comes in terms with the reality. Acceptance of the world around her becomes bran-new experience for Hagar. She finally comes to hard realizations that her will and proud can not control everything in the world and there are things she has to perceive as they are, not attempting to alter them. Ability to see different sides of the problem also becomes new experience for Hagar. As she states, how you see a thing it depends which side of the fence youre on (Laurence, p. 224)May be for the first time in her life Hagar realizes that there are other people around her and these people also have feelings, thoughts and emotions. Such simple conclusion becomes a very dependable breakthrough for this strong and proud woman who used to control everything and everybody during all her life. Hagar finally starts counting with the will of other people. She does several(prenominal) mercy deeds, which are done not because of some aesthetic value or in the attempt to make a good appearance. Hagar helps ill girl who can not get up. Later she talks to her son and tells him she loves him more than John, who died in the car accident. These actions require enormous amount of Hagars inner force. innocent acts of mercy are so new to her that she can not perceive them as something normal, like most of the people do. This transformation becomes the greatest action for Hagar.She lies to Marvin in the name of love. This lie is very vividly apposed to her proud refusal to lie for the sake of her dying brother many years ago. All these changes become a vivid indicator of big transformation, which happens to Hagar during the last days of her life. She finally realizes that there are things, which are more important than pride and good appearance, which have determined all her previous life. Such things as compassion, friendship and love for the first time uncover their true meaning for Hagar. The power uses the death to show the change in the perspective of the main character and to let the reader follow the person who leaves this world.From the other side new realization does not change her proud and independent nature. Hagar is still afraid and feels lonely, but she does not fight her destiny and the whole world any more. She makes her final decision to leave the world being proud and independent, like she has spent her whole life. In the last scene Hagar, dying, rejects the help of the deem to help her drink some water. She does it herself and this usual action which we do several times a day becomes an exploit for dying woman and proves her independency and power of her spirit.Margaret Laurence has chosen a difficult topic for her novel. She depicted the last days of the old woman left alone in her world, skirt by the memories of the past and lonely in her voluntary isolation. The author describes different stages Hagar passed before her death and analyses her emotional conditions during these stages. But w e meet death several times during the novel. We see in the memories of Hagar who lost almost all her dear people but didnt think about the death like about something which could happen to her. The death is described without embellishments and exaggerations. But ordinary and fashion descriptions help to get better understanding of the death and, finally, of life.Works Cited1. Margaret Laurence, The Stone Angel, New Canadian Library, Toronto, 1968.

Operational Management Kaplan Nortan Generic Map Essay

In Ka invent & Norton Generic scheme map, one perspective is the study and offshoot perspective. Explain the significance of this perspective. pen the requirement of the perspective in detail and what outcome can be achieved if it is followed.Significance * Learning and evolution strategies argon important for the long destination softenment of the plastered * Learning and growth perspective defines the impalpable assets which are needed to enable the activities and customer relationships to be performed at high train * It includes measurement for people (employee retention, training, skills, morale) * It also measure critical real fourth dimension information needed for front line employees * The chain of bring and subject relationships tend to cause returns in business processes , which in turn cause improvements in sales and financial measurement of profit mightiness. The direction of cause and set up relationship can be emphasized as Learning and growth Intern al business process Customer Financial * It continuously develop and deliver new innovative products and services * Organization innovation and learning perspective is used to maintain infrastructure needed for long border growth and improvements. Learning and Growth perspectiveIn learning and growth perspective establishments purpose is to achieve its mission and how it will sustain its ability to change and improve it defines the intangible assets that are needed to enable activities and customer relationship to be performed at high levels of performance so that the firm can serve its customer comfortably. This perspective is also the base of forming schema if base is well structured and queue uped with the governingal objective outline can prove itself more effective. It is important important for the long boundary development of the firm.RequirementsRequirements of learning and growth perspective are listed below * strategic competencies * Strategic technologies * Clima te for actionStrategic competencies Strategic competencies are the strategic skills and knowledge required by the work force to go the strategy. dodge itself is of no use until unless supported and implemented by the workforce of the organic law. Employees should be involved in decision making so that they considered themselves a bankrupt of the firm and take rational decisions about .If some(a) employee is doing well for the organization firm should reward him and give him recognition for the job that he has performed well this thing gives us the concept of motivation it is the driving force that drives a person to achieve its objective.Strategic Technologies These are the materials and process technologies, information system, databases, tools, and meshing required to support the strategy. Once strategy is made now it requires some technical parcel tools for its processing it can be some software that enable the work force to reduce times in the trading operations of the bus iness. An organization can gain competitive edge over its competitors by using technologies.Climate for actions Climate for action provides the cultural shifts needed to motivate, empower, and align the workforce behind the strategy . its the course of action that how organization is going to align its strategic competencies, strategic technologies with each other . organization matches its abilities with its strategies and oversees if it can perform as they have made the strategy. Its a point where organization checks its strategic fit between the organizational plan and resources employed for it . It accesses the climate prior to the action .OutcomesAs it focuses on intangible assets of the firm mainly on the internal skills and capabilities of the employees that are required to support the value creating internal processes. It also describes how technology people are combine to support the strategy and if it is implemented it can lead in the improvement in the internal processes , customers, and financial perspective

Mang Inasal Sample Paper Essay

Numbers of employees of mang inasal 21 employees including four-in-hand including the managers. Number of hours of operating theatre a day working hours, 8. Staff operation 800 am to 1000 pm, on customers, 900 am to 800 am. Reasons for choosing the branch location Since large number love to spend most of their time in the mall,Problems encountered during the business operation the manager laughs that she always encounters some problems to her subordinates, like being late at duties, some members that are hard headed, and reaction of customers that gets the wrong order and late serving. How they see their business 5 to 10 years from now? the manager says she can picture Mang Inasal being as more popular as before, growing bigger and better. Like jolibee, she sees Mang Inasal having many branches that extends internationally. renowned Experience in running the business Reasons for having that kind of business correspond to the manager, Miss Kristine Loayon, they were infor med during their job seminars and orientations, the owner of mang inasal, Edgar Injap Sia , had a target to choose a business that people will love and can be successful without a doubt. Since Filipinos love to eat, specially barbeques and Filipino dishes, then why not make food-chain business which features barbeques and pinoy foodsTypes of products, services offered? Philippine cuisine speedy food, deliveries and reservations of tables only at the second floor of mang inasal ormoc branch.ECOTAXA IntroductionMANG INASAL Philippines fastest growing barbeque fast food chain, serving chicken, pork barrel barbeque and other Filipino favorites, was first established on December12,2003 in Iloilo City. Currently, there are 445 branches nationwide and with over 10,000 employees system wide. MANG INASAL is doing its share in alleviating the unemployment burden of the country. The presence of every MANG INASAL in a certain cranial orbit provides not only employment but also opportuniti es to community members including suppliers of kalamansi, charcoal, banana tree leaves, vegetables, bamboo sticks, and other ingredients. It also indirectly gives income generating activities to many.MANG INASAL is operating at the following areas Bacolod, Iloilo, Roxas, Laguna, Bicutan, thermionic tube Manila, Davao, Cagayan De Oro, Koronadal, Ozamiz, Iligan, Surigao, General Santos, Pagadian, Batangas, Lucena, Naga City, Davao del Norte, Davao del Sur, Tagaytay, Palawan, Tacloban, Ilocos Sur and Tarlac. MANG INASAL is targeting to open 500 stores by 2012.Apart from the habitual food presentations of multinational food company copycats, Mang Inasal endeavors to adhere to elements that bear a distinctively Pinoy stamp-grilling with charcoal, rice wrapped in banana leaves, a steep concocted out of local spices and herbs, bamboo sticks for skewers, and the ambiance that encourages kinamot (the ilonggo term in eating with the hands) whenever chicken inasal is served. All these evok e a rush of nostalgia for tradition, culture, and most of all, Home. Mang Inasal is proud to do its share in alleviating the unemployment burden of the country. It is effectively stimulating economic activities in communities where branches are situated. Local suppliers of calamansi, charcoal, banana leaves, sorbeteros, vegetables, fish, bamboo sticks, and other ingredients, as well as LGUs, trisikad (pedicab) drivers, and a host of other enterprises are benefited by the presence of Mang Inasal in their area.Mang Inasal has steadily grown since it offered franchising. Mang Inasal has branches in Bacolod, Iloilo, Roxas, Metro Manila, Cebu, Davao, Kalibo, Tarlac, Boracay, Antique, Mindoro, Batangas, Pampanga, General Santos, Tuguegarao, Iligan, Bulacan, Cavite, Baguio, Laguna, Panabo, Cagayan De Oro, Lucena Surigao, Palawan, Agusan Del Sur, Malabon, Zamboanga Pagadian, Koronadal, Rizal, Pangasinan, Dipolog, La Union, Ozamiz, Kabankalan As of today, Mang Inasal has 423 branches nationw ide and counting. In Mang Inasal, Pinagsikapan naming laging mabilis, laging masarap, at laging abot-kaya so that the Pinoy can sincerely yours say, Kumbinsing

Is Decoherence a Solution for the Measurement Problem

AbstractDe cohesion is considered as wholeness of the important topics in quantum work out research ara. Some researchers res publicad that decoherence cultivated the measuring rod problem and on the different hand galore(postnominal) researchers advanced the opposite. In this paper we impart prove whether decoherence is a theme or non through an complete survey of the different bases, methodologies, and experiments. Index TermsQuantum com ordaine, decoherence, measuring stick problem entree Decoherence is considered as one of the important research areas since eighties.Quantum decoherence is the Loss of coherence or ordering of the phase angles surrounded by the components of a governance in quantum computing superposition and the consequence of this is sheer or probabilistically additive look (Zurek Today 10 (1991)) Wave s throw up analyze is the reduction of the fleshly possibilities into a item-by-item possibility as seen by observer tail end appear in quantum decoherence also it justifies the framework and can predict apply classical physics as an acceptable approximation Namiki and Pascazio 1991). However, decoherence is a tool that emerges out quantum stating point also it determines the location of the quantum classical boundary yet decoherence appear when the quantum carcass interacts with its environs in a thermodynamically irreversible way and that lead to prevent different factors in the quantum superposition of the outline and environments cast give out from interfering with each other Zurek Today 10 (1991)) Decoherence can be catched in different ways such as flowing learning from the system to the environment lead to lose information this is known as heat bath since each system is losing nearly of its energetic realm because of its surroundings environments (Kumar, Kiranagi et al. 012) in that respect is also another fit of decoherence that is called isolation which is the combination of the system and the environment which known as non- unitary accordingly the dynamics of the system alone are irreversible also as a result of combination of system and environment the entanglements are generated between them and that impart lead to sharing quantum information without transferring these information to the surroundings (Lidar and Whaley 2003) Describing how the wave function collaps occurs in quantum mechanics called metre problem. The disability of observing the bear upon directly lead to different nterpretations suppose quantum mechanics, also it rises too many qustions that each recitation moldiness answer. However there are s airyly researches provides aprove that the decoherence thrashd the measurment problem and some other researchers prove the opposite olibanum in this paper we will posit a comparasion between these twain different point of views (Kumar, Kiranagi et al. 2012) PROBLEM IDENTIFICATION Decoherence is a real challenge that prevents implementing quantum c omputers because the machines rely on undisturbed evolution of quantum coherences (Chen, Ang et al. 003), (Flitney and Abbott 2004) Decoherence provides an explanations for the appearance of the wave function adjourn it does not generate actual wave function collapse and that is the nature of quantum systems it leaks into the environment and that done by decomposing the component of the wave function from the coherent system and then applying phases to the environment(Flitney and Abbott 2004) P. W Anderson claimed that decoherence has solved the Quantum step problem while S. L Adler prove the opposite. Adler 2002) In this paper, we will conduct a comprehensive survey of the different views and experiments to come up with a solution for the relationship between decoherence and amount problem. Decoherence is the Solution Zurek (1991), Tegmark and cyclist (2001), and Anderson (2001) stated that decoherence has solved the quantum mensuration problem by eliminating the necessity for Von von Neumanns wave function collapse postulate. Osvaldo Pessoa Jr. wrote an denomination call Can the Decoherence Approach Help to Solve the Measurement Problem? He concluded that decoherence could help to solve measurement problem in un thawd systems. From that point, he wanted to enumerate on the open systems to solve the measurement problem of individual systems. He also mentioned that decoherence helps to get an approximate solution for the statistical version of the measurement problem. Wallace (2011) mentioned that decoherence explains why the measurement problem is a philosophical rather than a unimaginative problem and stated that decoherence could solve the measurement problem.He claimed that the quantum state continues to describe the somatogenetic state of the world. So, decoherence finds its natural position in the measurement problem as the process which explains why quantum mechanics can be fundamentally deterministic and non-classical, scarcely emergently c lassical. It does not benumb the aspect of Everetts proposal, which states that all are equally part of the underlying quantum reality. Decoherence is non the SolutionThe decoherence initiative was to explain the transformation from large to conventional by evaluating the relationships of a plan with a determining program or with the environment. It is realistic to moot about a large specialized substance or program of pollutants as a divided program boating in unemployed space. Dynamical Failing Styles Somehow do not like the idea of failure due to professionals emphasizeing to rig the pattern function cash advance so to advantage loss of the situation vector in a well described way.One way is to say that the pattern function, or at least an element of it, consistently gets hit in such a way as to cause localization in the position base. another(prenominal) way is to add a not unitary term into Schrodingers program. There are suggestions stated that we can infer using point ability to get the collapse of the wave function Tohmas Breuer at 1996 get a line to investigate these suggestions and apply it to recent results of quantum machines come across restrictions on measurement from inside.Tohmas Breuer count on these restrictions to come up with a phenomena of subjective decoherence therefore he split his article into split. The first part is measurement from inside and he prepares a usher ination to illustrate why it is impossible for an observer to make a distinction between all states in a system in which an observer is contained and that consider as restriction on the quantifiability from inside, he conclude that bigger system O need more parameters to fix its state.However, this will lead to situations that big O can be determined of each physically possible state by the state of a subsystem A together with some constraint. Second part is EPR-Correlations and he focus on situation which stronger results hold when we take into account fin icky features of quantum mechanistic situations for example if we obtain ii systems A and some environment R then the union of two system A ? R equal to Big O. also if both systems A and R have Hilbert spaces HA and HR as state spaces then EPR correlations can be obtained in the vector states ?? HA HR .Therefore he conclude that A con not make a distinction between states of O which is make difference only in the EPR correlations between A and R. provided observers can only be able to make a measurement of EPR correlations between A and R in A ? R(Breuer 1996) David Wallace wrote his article to achieve two goals the first one is to present an account of how quantum measurements are dealing with in modern physics in other newsworthiness quantum measurements does not involve a collapse of the wave functions also to present the measurement problem from that account perspective of view.The second part is concentre on clarifying the role of decoherence plays in modern measurement p ossibility and what affects it has on the different strategies that have been proposed to solve measurement problem. Wallace concluded that it seems not possible to have a complete understating of the microscopic predictions quantum mechanisms without interpreting the state in a probabilistic way and that because of interference since quantum states cannot be estimate of as probability distributions in physical states of airs.Therefore it is allowable to try to resolve the incoherence by two ways, the first one by philosophical methods which means trying hard to think about how to make a full arrest quantum states so as to come out with a non-incoherent way, also the second way done by making modifications on the physics which means trying to make a replacement of the quantum mechanics by using some new theory which does not leading(predicate) facie lead to the conceptual incoherence.Finally, Wallace state that the natural role of decoherence can be found in the measurement prob lem as the process which provides an explanations require why quantum mechanics, construe can be basically not classical and deterministic, but critically classical(Wallace 2011) Dan Stahlke based on application he made state that the most important point of decoherence theory is that it provides understanding about the process of wave collapse. Some systems need to be make in way that it waistband in coherent superposition.However, tendency of system that been in superposition can be immediately calculated. Also he stated that decoherence does not give the ultimate solution in the measurement problem but it bring some light to the matter(Stahlke 1999) gookimilian Schlosshauer makes a distinctive discussion regard the role of decoherence in the foundation of quantum mechanics, and cerebrate of the effectiveness of decoherence regard the measurement problem. He concludes that within a stock variant of quantum mechanics that decoherence cannot solve the problem of decided out comes in quantum measurement.Therefore he mention the effectiveness of environment super selection of quasiclassical pointer states along with the local superposition of interference terms can be put to large use in physical motivation, assumptions and rules regard alternative commentary approaches that can change the strict orthodox eigenvalue-eigenstate link or make modification on the unitary dynamics to account for the awareness of definite outcomes(Schlosshauer 2005) Elise M.Crull mention in his article that it has been claimed that decoherence has solved the measurement problem. In other hand, some researchers stated that it does not solve the measurement problem. However, the Crull target is Which measurement problem? , thus he argue three questions depending on Max Schlosshauer which has neat catalog on the different problems which called the measurement problem(Schlosshauer 2008 Crull 2011) Harvey chocolate-brown stated that there are many attempts to proof the insolubili ty of the measurement problem in non-quantum mechanics.We can use these attempts for quantum mechanics. These proofs tend to establish that if mechanical interaction between object system A and measuring promoter B is described through a suitable defined unitary operator on the Hilbert tensor product space, so the final state of the A + B together cannot be described by a tightfistedness operator of a specific kind in that space.Therefore this leads us to a resolution in terms of weighted projections which be useful to interpreted as mixture of pure A + B states, which are eigenstates match to the pointer position that observable connected with the instrument(Brown 1986) Ford, Lewis and Connell count on a book Decoherence and the Appearance of a Classical World in Quantum Theory (Giulini, Joos et al. 1996) which state that irreversible coupling to the environment seems to have bring about widely accepted and even quite popularDuring the last decade, not least through the variou s contributions by Woljciech Zurek and his collaborators. And he conclude that habitual and simple formulation of quantum measurement gives a good method regard discussing quantum stochastic systems(Ford and Lewis 1986) . Also authors stated that decoherence appear at high temperature with or without dissipation and the time for both cases are the same furthermore at zero temperature, decoherence occurs only in the presence of dissipation(Ford, Lewis et al. 001) In 1980s and 1990s techniques are established to cool single ions captured through a trap and to control their state by using laser light and the single ion can be observed using photons with minimal interaction with the environment. Photons can observed without being destroyed during interaction together with atoms in designed experiment. That leads to make a study regard pioneers that make a test for basis of quantum mechanics also the transition between microscopic and microscopic world.The most important stage in contr olling the quantum state regard ion is cooling it to the lowest zippo of the trap using a common technique called sideband cooling(F. Diedrich, Bergqvist et al. 1989) this technique consists of exiting the ion, increasing inside energy also decreasing the vibration energy(SCIENCES 2012) Bas Hensen starting his discussion by defining the measurement problem and he stated that measuemet problem swallow naturally from quantum theorys success through describing the realm regard microscopic particles also permitting them to have definite values for quantities like urge and position.Then he split the problem into several parts. The first two parts are the problem of outcomes why does one perceive a single outcome among the many possible ones in equation? , The problem of the collapse What kind of process causes the state of the system to collapse to the outcome one perceived (in the sense that a repeated measurement yields the same answer)? in these two part he found that in quantum t he world must be divided into a wave quantum system and the rest stays in some classical system.Also in accuracy point of view the division is made one way or another in a particular application. The third part is The problem of interference Why do we not observe quantum interference effects on macroscopic scales? in this part author stated that the best way to illustrate this problem by using the double putz experiment. The experiment shows that the physical setup suggests that grouping the probability distribution gained with either one of the slit opened should occur in the probability distribution regard the two slits opened.For this situation of electrons as particles the probability distribution regard course differs, but regard a similar setup using macroscopic particles it doesnt(Hensen 2010 ) Dieks reviewed several proposals that solved the quantum mechanical measurement problem by pickings into account that in measurement interactions there are many undetected degrees o f freedom. He found out that such solutions are unsatisfactory as they stand, and must be supplemented by a new empirical interpretation of the formal state description of quantum mechanics (Dieks 1989).Zurek mentioned in Decoherence, Einselection, and the Quantum Origins of the Classical that decoherence is caused by the interaction in which the environment in effect monitors certain observables of the system, destroying coherence between the pointer states corresponding to their eigenvalues. Then, he mentioned that when the measured quantum system is microscopic and isolated, this restriction on the predictive utility of its correlations with the macroscopic apparatus results in the effective collapse of the wave packet which implicitly states that decoherence did not solve the measurement problem (Zurek 2003).Elby scrutinized the claim that the measurement problem is solved by decoherence, by examining how modal and relative-state interpretations can use decoherence. He mentione d also that although decoherence cannot pull through these interpretations from general metaphysical difficulties, decoherence may help these interpretations to pick out a preferred basis (Elby 1994). Janssen mentioned that the alleged relevance of decoherence for a solution of the measurement problem is subjected to a detailed philosophical analysis.He reconstructed a non-standard decoherence wrinkle that aimed to uncover some hidden assumptions underlying the approach. He concluded that decoherence cannot squall the preferred-basis problem without adding new interpretational axioms to the standard formalism (Janssen 2008). Busch et al (1996) explained decoherence using the many-worlds interpretation and stated the decoherence cannot solve the measurement problem. Leggett (2005) concentrated on the paradox of Schrodingers cat or the quantum measurement paradox to prove that dechorence is not a practical solution.Other researchers and scientists including Gamibini and Pullin (200 7), Zurek (2002), Joos and Zeh (1985), Bell (1990), Albert (1992), Bub(1997), Barrett (1999), Joos (1999), and Adler (2002) stated that decoherence did not solve the measurement problem. Conclusion There is a serious and unresolved quantum measurement problem. Some, like Ghirardi, Rimini, and Weber (1986), try to solve it by modifying quantum mechanics. If successful, such attempts would result in a theory, distinct from but closely related to quantum mechanics, that is no longer subject to a measurement problem. That problem may be unsolvable (Healey 1998).

Unit 208 Support Children and Young Persons Health and Safety

Level 2 Certificate in Supporting Teaching and Learning in Schools social unit 208 Support children and young peoples wellness and safety written Questions 1. 1 Give ex axerophtholles of how current health and safety legislation, policies and procedures be utilize in your school The health & safeguard Act 1974 down the stairs this act individuals in any organisation be required to condition that they report any hazards, follow the schools safety policy, make sure their actions do not harm themselves or some others and use any safety equipment that is provided. on that point are posters that explain the employers and employees responsibilities throughout Longford honey oil basal School to instigate everyone how to comply with the act. My school complies with the act by ensuring any hazards are report to Mr Provaker, the care shortenr. By having cleaners coming in daily to ensure all areas of the school are clean and tidy. alone equipment is stored in a locked cup bill. discharge evacuation procedures are vauntinged throughout the school in each schoolroom.Safety equipment is used by staff, for example staf on vacation spot duty break-dance high visability vests and carry first aid kits. Food Hygiene canon 2006 Covers the safe preparation and storage of food. All of the cooks, kitchen and serving staff at Longford Park Primary School comply with this by holding an up to date food hygiene certificate and having annual re-tests. There are posters in the kitchen reminding staff of good practice i. e which colour chopping board to use for which food and how to store food in the fridge correctly. guess Assesment This is to identify potential hazards to staff and children, the risks are evaluated and steps to minimize the gap of the situation arising are set out, Theses are make for solar day to day activities in all areas of the school and for new activities such(prenominal)(prenominal) as school trips. My school complies with this by carrying out risk assessment for activites during lesson planning and deep when all the children at Longford Park Primary School went to the local subject to watch a pantomime, a through risk assessment was done before hand.COSHH 2 Regulations 2002 Longford Park Primary School complies with this by retention all COSHH items in a locked cupboard by the staff toilets. entropy Sheets for all the chemicals are displayed on the wall in the cupboard. Al items are stored out of reach of the children and in its original packaging. Protective clo function such as gloves, masks and goggles are provided when nessecary. The key for the cupboard is kept with the caretaker, Mr Provaker. all Child Matters This has 5 outcomes 1 Be wellnessy 2 Be Safe 3 Enjoy 4- Postive 5 Economic Longford Park Primary school promotes these outcomes by promoting healthy eating the children had a piece of yield during their morning break, by teaching children how to keep themselves safe from possibilitys and harm i. e An assemble to inform about the risks of decampworks, no running in corridors, how to safely carry scissors. They children do an exercise video called Activate first thing in the morning whilst the register is being taken and a cycle proficiency course is offered to all children in year five.Fire Procedures Longford Park Primary School has procedures tor evacuationg all areas of the school during a fire, the escape highroad and assembly points is displayed on an Action Plan in all classrooms, corridors and other areas of the school. The schools fire alarm system is checked weekly and a fire drill is carried out every term, the fire drill is recorded and and then evaluated to detertime if it could be done better. Emergency exits are clearly marked, in my classroom the fire exit is the door that leads directly out to the play ground.Health and Safety (First Aid) 1981 Longford Park Primary School complies with this by keeping easily stocked first aid boxes on the teachers desk in each classroom and are carried by playground supervisors. Designated first aiders are appointed and fitly trained with a list of all first aiders on display in the staff room so that all staff slam who to refeer to if a child has an accident, all accidents are recorded in the accident book. 1. 1 continued &8212&8212&8212&8212&8212&8212&8212&8212&8212&8212&8212&8212&8212&8212&8212&8212- 1. 2 How is health and safety overseeed and maintained in your school? (Describe) The Health and Safety representative, Mrs Walker carries out regular checks by walking around the school and outside areas * Weekly staff meetings are used to address and health and safety concerns * Equipment, material and the environment are checked and any hazards are identified and removed * Lunchtime supervisors monitor health and safety in the dining hall and in the playground looking out for risks and removing or minimising them or reporting them. * Hand dry wash facilities are available outsid e every classroom and children wash their workforce after being outside. Boxes of tissues on each table help to the the scatter of germs when coughing and sneezing. * All electrical and fire extinguishers are checked yearly by a qualified person and a label is stuck on the checked equipment with the date it was tested. Only equipment that has been checked and has a label should be used. * Food hygiene procedures are in place for cooks, kitchen and serving staff. 1. 3 How people in my school are made aware of risks & hazards and encouraged to work safely (Describe) &8212&8212&8212&8212&8212&8212&8212&8212&8212&8212&8212&8212&8212&8212&8212&8212- 1. Identify the lines of responsibility and reporting for health and safety in your school. bye Teacher, Mandy Walker or Deputy Head Mina Provarker has ultimate responsibility for Health and Safety in school. The Health and safety officer at Longford Park Primary School is Mr Provarker and is prudent for monitoring Health and Safety b y carrying out routine inspections or equipment and premisis and for ensuring everyone is aware of the procedures for reporting and recording hazards. The Caretaker Mr Provarker is responsible to dealing with and removing any hazards.All staff and students are responsible for reporting health and safety issues such as hazards and accidents. Students would report issues to a suitable member of staff harmonize to the nature of the issue. 3. 1 Outline the importance of taking a fit approach to risk reignment Children should learn to be able to take some risks and most activities will carry some portion of danger but they should be given the opportunity to assess risks for themselves by exploring and by challenging themselves and by discussing risks and safety.Childrens safety is important but we need to be careful not to be over protective or they may be prevented from assessing risks, exploring and learning, discovering the world around them or recognising their own limitations. I f childrens experiences are hold in due to an adults anxieties they are more likely to find it difficult to asses and manage risks as they develop and may not feel confident when move new things. Think of 2 examples of activities in your placement where there is an element of measured risk. How does the risk involved balance with the learning experience? exemplification 1 Example 2

Introduction to Epidemiology

Aug 17 2011 approach to Epidemiology Epidemiology is considered the basic attainment of gay race wellness, and with good reason. Epidemiology is A quantitative basic science built on a working friendship of probability, statistics, and ponderous interrogation methodology A method of causal reasoning based on set aboutment and examen hypotheses pertaining to accompaniment and pr grammatical caseion of morbidity and death rate A tool for formula wellness action to promote and protect the populaces wellness based on science, causal reasoning, and a dose of practical domain sense (2).As a public wellness discip line mount, epidemiology is in appeaseed with the spirit that epidemiological training should be social occasion to promote and protect the publics wellness. Hence, epidemiology involves both(prenominal) science and public wellness practice. The term employ epidemiology is just astir(predicate) clock fourth dimensions go for to pass the coating o r practice of epidemiology to address public wellness issues. types of applied epidemiology include the pursuance the monitoring of reports of communic competent affections in the club the memorise of whether a particular(prenominal) dietary comp atomic number 53nt watchs your adventure of developing freightercer evaluation of the effectiveness and impact of a cholesterol cognisance program analysis of historical tr sacks and current selective information to project incoming public wellness resource adopts Objectives after(prenominal) news reporting this muniment and reply the questions in the exercises, you should be able to do the fol brokening Define epidemiology t wholey the historical evolution of epidemiology Describe the elements of a representative translation and nominate the effect of changing the value of each of the elements mention the key features and economic consumptions of descriptive epidemiology total the key features and t heatrical roles of uninflectedal epidemiology List the cardinal comp one(a)nts of the epidemiologic troika List and describe Hills criteria of causation Understand the ingrained history of sickness and the three soulfulnessas of pr outcomeion Understand infectivity, pathogenicity, and virulence List and describe primary applications of epidemiology in public health practice List and describe the dissimilar elans of contagion of communicable affection in a population 1 rapscallion 2 utilize Epidemiology I A subroutine of exercises ar provided. It is suggested you endeavor to answer these questions and then comp be your answers with those at the end of this document. Introduction The word epidemiology comes from the Greek words epi, meaning on or upon, demos, meaning lot, and logos, meaning the study of. M both definitions halt been proposed, plainly the following definition captures the underlying principles and the public health spirit of epidemiology Epidemiology is the study of the distribution and determinants of health- tie in states or events in specify populations, and the application of this study to the concord of health problems. (17) Key terms in this definition job some of the important principles of epidemiology. Study Epidemiology is a scientific discipline with sound methods of scientific inquiry at its fixation. Epidemiology is selective information-driven and relies on a systematic and unbiased nestle to the collection, analysis, and interpretation of entropy.Basic epidemiologic methods tend to rely on c arful rumination and use up of valid comparison groups to assess whether what was observed, such as the number of graphic symbols of infirmity in a particular playing field during a particular time period or the frequency of an word picture among persons with sickness, differs from what top executive be expected. However, epidemiology to a fault draws on methods from early(a)wise scientific fields, includin g biostatistics and informatics, with biologic, economic, social, and behavioral sciences. In fact, epidemiology is a lot set forth as the basic science of public health, and for good reason. First, epidemiology is a quantitative discipline that relies on a working knowledge of probability, statistics, and sound research methods. sec, epidemiology is a method of causal reasoning based on developing and testing hypotheses grounded in such scientific fields as biology, behavioral sciences, physics, and ergonomics to explicate health-related behaviors, states, and events. However, epidemiology is non just a research activity but an integral component of public health, providing the foundation for say practical and appropriate public health action based on this science and causal reasoning. Determinants Epidemiology is also use to search for determinants, which ar the causes and an some disparate(prenominal) factors that influence the particular of trouble and former(a) hea lth-related events.Epidemiologists assume that unwellness does not occur randomly in a population, but happens entirely when the advanced accumulation of roll on the line factors or determinants exists in an mortal. To search for these determinants, epidemiologists use analytic epidemiology or epidemiologic studies to provide the Why and How of such events. They assess whether groups with diametrical rates of unhealthiness differ in their demographic features, genetic or immunologic make-up, behaviors, environmental exposures, or other so-called potential luck factors. Ideally, the findings provide sufficient inference to direct prompt and effective public health experience and prevention measures. Health-related states or eventsEpidemiology was originally focused only if on epizootics of communicable ailments3 but was subsequently expanded to address autochthonal communicable diseases and non-communicable infectious diseases. By the middle of the 20th Century, additi ve epidemiologic methods had been unquestionable and applied to degenerative diseases, injuries, birth defects, maternal-child health, occupational health, and environmental health. consequently epidemiologists began to look at behaviors related to health and well-being, such as total of exercise and seat belt use. Now, with the recent explosion in molecular(a) methods, Introduction to Epidemiology Epi 592J rogue 3 epidemiologists rear end make important strides in examining genetic markers of disease attempt.Indeed, the term health related states or events whitethorn be seen as anything that affects the well-being of a population. Nonethe slight(prenominal), numerous epidemiologists unflustered use the term disease as shorthand for the wide range of healthrelated states and events that atomic number 18 studied. Specified populations Although epidemiologists and direct health-cargon providers (clinicians) atomic number 18 both concerned with occurrence and get over of d isease, they differ greatly in how they view the alter role. The clinician is concerned about the health of an individual the epidemiologist is concerned about the collective health of the people in a community or population. In other words, the clinicians enduring is the individual the epidemiologists patient is the community.Therefore, the clinician and the epidemiologist pass water different responsibilities when faced with a person with illness. For example, when a patient with diarrhoeal disease presents, both are provoke in establishing the correct diagnosing. However, part the clinician commonly focuses on treating and lovingness for the individual, the epidemiologist focuses on marking the exposure or source that caused the illness the number of other persons who whitethorn beget been similarly exposed the potential for further get around in the community and interventions to prevent additional instances or recurrences. Application Epidemiology is not just th e study of health in a population it also involves foundering the knowledge gained by the studies to community-based practice.Like the practice of medicine, the practice of epidemiology is both a science and an art. To make the proper diagnosis and prescribe appropriate treatment for a patient, the clinician combines medical (scientific) knowledge with experience, clinical judgment, and consciousness of the patient. Similarly, the epidemiologist uses the scientific methods of descriptive and analytic epidemiology as well as experience, epidemiologic judgment, and understanding of local conditions in diagnosing the health of a community and proposing appropriate, practical, and acceptable public health interventions to control and prevent disease in the community. SummaryEpidemiology is the study (scientific, systematic, information-driven) of the distribution (frequency, conventionalism) and determinants (causes, take chances factors) of health-related states and events (not ju st diseases) in specified populations (patient is community, individuals viewed collectively), and the application of (since epidemiology is a discipline at heart public health) this study to the control of health problems. Evolution Although epidemiologic cerebration has been traced from Hippocrates (circa cd B. C. ) through Graunt (1662), Farr, century (both mid-1800s), and others, the discipline did not blossom until the end of the Second World contend. The contributions of some of these early and much recent thinkers are described next. Hippocrates (circa 400 B. C. ) attempted to explain disease occurrence from a rational instead of a supernatural viewpoint. In his essay entitle On Airs, Waters, and Places, Hippocrates suggested that environmental and host factors such as behaviors might influence the development of disease.Another early contributor to epidemiology was fanny Graunt, a capital of the join Kingdom haberdasher who published his landmark analysis of mortalit y data in 1662. He was the first to quantify patterns of birth, final st hop on, and disease occurrence, noting male-female disparities, high infant mortality, urban-rural varietys, and seasonal worker variations. No one built upon Graunts work until the mid-1800, when William Farr began to systematically collect and contemplate Britains mortality statistics. Farr, considered the father of modern vital statistics and disease surveillance, developed many of the basic practices used to twenty-four hour period in vital statistics and disease assortment. He extended the epidemiologic analysis of morbidity and mortality data, spirit at page 4 Applied Epidemiology I he effects of marital status, occupation, and altitude. He also developed many epidemiologic concepts and techniques still in use today. Meanwhile, an anesthesiologist named John reversal was conducting a serial publication of investigations in capital of the United Kingdom that later earned him the title the father of epidemiology. cardinal eld before the development of the microscope, one C conducted studies of plaguey epidemic cholera extravasations both to happen the cause of the disease and to prevent its recurrence. Because his work classically illustrates the sequence from descriptive epidemiology to shot generation to hypothesis testing (analytic epidemiology) to application, we will consider deuce of his efforts.It is important to mention that at the time of John Snows investigations the much or less widely accepted cause of diseases, including cholera, was due to miasma, or revolting air. Therefore most(prenominal) regardd that cholera was transmitted by air, especially rotten air near piddle sum up. The germ theory, that disease was transmitted by microbes, did not gain acceptance until later in the 1800s. Snow conducted his classic study in 1854 when an epidemic of cholera developed in the thriving straightforwardly of London. He began his investigation by determ ining where in this area persons with cholera pop offd and worked. He then used this entropy to symbolise the distribution of brasss on what epidemiologists call a spot be. His map is fork upn in look 1. 1.Because Snow believed that water was a source of infection for cholera, he marked the spot of water middles on his spot map, and then looked for a relationship betwixt the distribution of cholera fictional character households and the location of pumps. He presentmentd that more case households clustered around authorized pumps, especially the panoptic highway pump, and he concluded that the Broad Street pump was the most potential source of infection. Questioning residents who lived near the other pumps, he found that they avoided certain pumps because the water they provided was grossly contaminated, and that other pumps were located too inconveniently for most residents of the grand Square area.From this instruction, it appeared to Snow that the Broad Street pump was probably the primary source of water for most persons with cholera in the Golden Square area. He established, however, that it was too concisely to draw that conclusion because the map showed no cholera cases in a two-block area to the east of the Broad Street pump. Perhaps no one lived in that area, or by chance the residents were somehow protected. Upon investigating, Snow found that a brewery was located there and that it had a deep well on the premises where brewery workers, who also lived in the area, got their water. In addition, the brewery allotted workers a daily quota of malt liquor. Access to these uncontaminated rations could explain why none of the brewerys employees contracted cholera.To provide further demonstration that the Broad Street pump was the source of the epidemic, Snow gathered entropy on where persons with cholera had obtained their water. Consumption of water from the Broad Street pump was the one common factor among the cholera patients. A ccording to legend, Snow removed the handle of the Broad Street pump and aborted the outbreak. Snows help major contribution involved another investigation of the aforesaid(prenominal) outbreak of cholera that occurred in London in 1854. In a London epidemic in 1849, Snow had noted that di inexorables with the highest mortalities had water supplied by two companies the Lambeth Company and the Southwark and Vauxhall Company. At that time, both companies obtained water from the Thames River, at in cope points eatstream of London.In 1852, the Lambeth Company moved their water works upstream from London, thus obtaining water free of London sewage. When cholera returned to London in 1853, Snow realized the Lambeth Companys relocation of its intake point would allow him to differentiate districts that were supplied with water upstream from London with districts that received water downstream from London. instrument panel 1. 1 shows what Snow found when he made that comparison for ch olera mortality ein truthwhere a 7-week period during the summer of 1854. Introduction to Epidemiology Epi 592J Page 5 convention 1. 1 Distribution of cholera cases in the Golden Square area of London, August-September 1854 tabularize 1. deathrate from cholera in the districts of London supplied by the Southwark and Vauxhall and the Lambeth Companies, July 9-August 26, 1854 Districts with Water Supplied by nation Deaths from Mortality Risk per (1851 Census) cholera 1,000 Population 167,654 844 5. 0 Southwark and Vauxhall Co. only Lambeth Co. only Both companies kickoff 27 19,133 300,149 18 652 0. 9 2. 2 Page 6 Applied Epidemiology I The data in Table 1. 1 show that the chance of death from cholera was more than 5 times higher(prenominal) in districts served only by the Southwark and Vauxhall Company than in those served only by the Lambeth Company. Interestingly, the mortality encounters in districts supplied by both companies fell between the risks for districts served excl usively by all company.These data were consistent with the hypothesis that water obtained from the Thames below London was a source of cholera. Alternatively, the populations supplied by the two companies whitethorn have differed on a number of other factors which affected their risk of cholera. To test his water supply hypothesis, Snow focused on the districts served by both companies, because the households deep down a district were generally comparable except for which company supplied water. In these districts, Snow identified the water supply company for every house in which a death from cholera had occurred during the 7-week period. Table 1. 2 shows his findings. Table 1. Mortality from cholera in London related to the water supply of individual houses in districts served by both the Southwark and Vauxhall Company and the Lambeth Company, July 9August 26, 1854 Water Supply of soul House Population Deaths from Mortality risk per (1851 Census) Cholera 1,000 Population South wark and Vauxhall Co. 98,862 419 4. 2 Lambeth Co. Source 27 154,615 80 0. 5 This further study added endure to Snows hypothesis, and demonstrates the sequence of steps used today to check out outbreaks of disease. Based on a characterization of the cases and population at risk by time, get, and person, Snow developed a testable hypothesis. He then time-tested this hypothesis with a more rigorously designed study, ensuring that the groups to be canvasd were comparable. After this study, efforts to control the epidemic were directed at changing the location of the water intake of the Southwark and Vauxhall Company to reduce sources of contamination.Thus, with no knowledge of the existence of microorganisms, Snow demonstrated through epidemiologic studies that water could serve as a vehicle for transmitting cholera and that epidemiologic schooling could be used to direct prompt and appropriate public health action. More information on John Snow can be found at www. ph. ucla. edu/ epi/snow. html In the mid- and late-1800s, many others in Europe and the United States began to apply epidemiologic methods to investigate disease occurrence. At that time, most investigators focused on crisp infectious diseases. In the 1900s, epidemiologists extended their methods to noninfectious diseases.The period since the Second World War has seen an explosion in the development of research methods and the theoretical underpinnings of epidemiology, and in the application of epidemiology to the entire range of health-related outcomes, behaviors, and even knowledge and attitudes. The studies by Doll and Hill (13) linking smoking to lung cancer and the study of cardiovascular disease among residents of Framingham, Massachusetts (12), are two examples of how pioneering researchers have applied epidemiologic methods to chronic disease since World War II. Finally, during the 1960s and early 1970s health workers applied epidemiologic methods to eradicate smallpox global.This was a n achievement in applied epidemiology of unprecedented proportions. Today, public health workers throughout the world accept and use epidemiology routinely. Epidemiology is a great deal practiced or used by non-epidemiologists to characterize the health of their communities and to solve day-to-day problems. This landmark in the evolution of the discipline is less dramatic than the eradication of smallpox, but it is no less important in improving the health of people everywhere. Introduction to Epidemiology Epi 592J Page 7 Uses Epidemiology and the information generated by epidemiologic methods have many uses. These uses are categorized and described below. Population or community health judging.To set policy and intent programs, public health officials must assess the health of the population or community they serve and determine whether health services are avai research lable, accessible, effective, and efficient. To do this, they must find answers to many questions What are th e actual and potential health problems in the community? Where are they? Who is at risk? Which problems are declining over time? Which ones are increasing or have the potential to enlarge? How do these patterns relate to the level and distribution of services available? The methods of descriptive and analytic epidemiology provide ways to answer these and other questions.With answers provided through the application of epidemiology, the officials can make informed decisions that will lead to improved health for the population they serve. Individual decisions. People whitethorn not realize that they use epidemiologic information in their daily decisions. When they decide to stop smoking, take the stairs instead of the elevator, order a salad instead of a cheeseburger with French fries, or choose one method of contraception instead of another, they whitethorn be influenced, consciously or unconsciously, by epidemiologists assessment of risk. Since World War II, epidemiologists have pr ovided information related to all those decisions.In the 1950s, epidemiologists documented the increased risk of lung cancer among smokers in the 1960s and 1970s, epidemiologists noted a physique of benefits and risks associated with different methods of birth control in the mid-1980s, epidemiologists identified the increased risk of human immunodeficiency virus (HIV) infection associated with certain sexual practiceual and drug-related behaviors and, more positively, epidemiologists continue to document the role of exercise and proper diet in reducing the risk of heart disease. These and hundreds of other epidemiologic findings are directly relevant to the choices that people make every day, choices that affect their health over a lifetime. end the clinical picture. When studying a disease outbreak, epidemiologists depend on clinical medical students and lab scientists for the proper diagnosis of individual patients.But epidemiologists also extend to physicians understanding of the clinical picture and natural history of disease. For example, in late 1989 three patients in New Mexico were diagnosed as having myodynias (severe muscle pains in dresser or abdomen) and unexplained eosinophilia (an increase in the number of one type of white blood carrell). Their physicians could not some(prenominal)ise the cause of their emblems, or position a name to the disorder. Epidemiologists began looking for other cases with similar symptoms, and within weeks had found adequate additional cases of eosinophilia-myalgia syndrome (EMS) to describe the illness, its complications, and its risk of mortality.Similarly, epidemiologists have documented the trend of HIV infection, from the initial exposure to the development of a wide variety of clinical syndromes that include maturated immunodeficiency syndrome ( moxie up). They have also documented the numerous conditions associated with tooshie smokingfrom pulmonary and heart disease to lung and cervical cancer. Search for causes. very much of epidemiologic research is devoted to a search for causes, factors which influence ones risk of disease. close totimes this is an academic pursuit, but more often the goal is to notice a cause so that appropriate public health action might be taken. It has been said that epidemiology can never prove a causal relationship between an exposure and a disease. Nevertheless, epidemiology often provides enough information to support effective action.Examples include John Snows removal of the pump handle and the withdrawal of a particularised brand of tampon that was linked by epidemiologists to toxic dump syndrome. Another example is the testimony that children not be given acetylsalicylic acid due to its association with Reye syndrome. Just as often, epidemiology and laboratory science meet to provide the evidence needed to establish causation. For example, a team of epidemiologists were able to identify a variety of risk factors during an outbreak of pneumonia among persons attending the the Statesn Page 8 Applied Epidemiology I Legion Convention in Philadelphia in 1976, called Legionnaires disease. However, the outbreak was not solved until the Legionnaires boron was identified in the laboratory near 6 months later. Disease control, elimination, and eradication. The crowning(prenominal) goal of epidemiology is to improve the health of populations and through the reduction in disease. The definitions of disease control, elimination, and eradication as applied to infectious diseases are given below. (Dowdle WR. The principles of disease elimination and eradication. MMWR 48(SU01)23-7, 1999. ) Control The reduction of disease relative incidence, prevalence, morbidity or mortality to a locally acceptable level as a leave of deliberate efforts continued intervention measures are necessitate to maintain the reduction. Example diarrheal diseases.Elimination of disease Reduction to zero of the incidence of a specified disease i n a defined geographical area as a result of deliberate efforts continued intervention measures are required. Examples neonatal tetanus. Elimination of infections Reduction to zero of the incidence of infection caused by a specific agent in a defined geographical area as a result of deliberate efforts continued measures to prevent reestablishment of transmission are required. Example measles, poliomyelitis. Eradication Permanent reduction to zero of the worldwide incidence of infection caused by a specific agent as a result of deliberate efforts intervention measures are no lengthy needed. Example smallpox.Extinction The specific infectious agent no semipermanent exists in nature or in the laboratory. Example none. The above definitions are specific to infectious disease, but some of the concepts can carry over to other conditions, such as nutritional disorders, inborn errors of metabolism, and chronic diseases. Introduction to Epidemiology Epi 592J Page 9 answer 1. 1 In the ear ly 1980s, epidemiologists recognized that AIDS occurred most frequently in men who had sex with men and in intravenous drug users. Describe how this information might be used for some(prenominal)ly of the following a. Population or community health assessment b. Individual decisions c. Search for causes Page 10 Applied Epidemiology I The epidemiologic ApproachLike a newspaper reporter, an epidemiologist determines What, When, Where, Who, and Why. However, the epidemiologist is more carely to describe these concepts in around different terms case definition, time, place, person, and causes. Case Definition (What? ) The identification of disease can be based on symptoms, signs, and diagnostic tests. A symptom is a sensation or change in health undergo by an individual. Examples of symptoms reported by an individual are a spit up, fatigue, anxiety, and back pain. Signs, or signs of disease, are an objective evidence of disease observed by someone other than the affected individua l, such as a physician or nurse.A case definition is a set of standard criteria for decision making whether a person has a particular disease or other health-related condition. By using a standard case definition we attempt to ensure that every case is diagnosed in the same way, regardless of when or where it occurred, or who identified it. We can then compare the number of cases of the disease that occurred in one time or place with the number that occurred at another time or another place. For example, with a standard case definition, we can compare the number of cases of hepatitis A that occurred in New York city in 1991 with the number that occurred there in 1990. Or we can compare the number of cases that occurred in New York in 1991 with the number that occurred in San Francisco in 1991. With a standard ase definition, when we find a dissimilarity in disease occurrence, we know it is likely to be due to a real difference or due to the quality of the disease reporting system quite an than the result of differences in how cases were diagnosed. A case definition consists of clinical criteria and, sometimes, limitations on time, place, and person. The clinical criteria usually include confirmatory laboratory tests, if available, or combinations of symptoms (subjective complaints), signs (objective somatogenetic findings), and other findings. For example, see the case definition for rabies below notice that it requires laboratory confirmation. Rabies, Human Clinical description Rabies is an acute encephalomyelitis that to the highest degree always progresses to coma or death within 10 old age of the first symptom.Laboratory criteria for diagnosis Detection by direct fluorescent antibody of viral antigens in a clinical specimen (preferably the brain or the poise surrounding hair follicles in the nape of the neck), or Isolation (in cell culture or in a laboratory animal) of rabies virus from saliva, cerebrospinal fluid (CSF), or central nervous system tissue, or Identification of a rabies-neutralizing antibody titer greater than or equal to 5 (complete neutralization) in the serum or CSF of an unvaccinated person Case classification substantiate a clinically compatible illness that is laboratory sustain Comment Laboratory confirmation by all of the above methods is strongly recommended. Source 3 Compare this with the case definition for Kawasaki syndrome provided in crop 1. 3 on page 12. Kawasaki syndrome is a childhood illness with pyrexia and rash that has no known cause and no specifically typical laboratory findings. nonice that its case definition is based on the presence of fever, at least four of cinque specified clinical findings, and the lack of a more reasonable explanation. A case definition whitethorn have several sets of criteria, depending on the certainty of the diagnosis. For example, during an outbreak of measles, we might severalize a person with a fever and rash as having a Introduction to Epidemiology Epi 592J Page 11 shadowed, probable, or confirmed case of measles, depending on what additional evidence of measles was present. In other situations, we may temporarily classify a case as suspect or probable until laboratory results are available. When we receive the laboratory report, we then reclassify the case as both confirmed or not a case, depending on the lab results.In the midst of a large outbreak of a disease caused by a known agent, we may permanently classify some cases as suspect or probable, because it is unnecessary and wasteful to run laboratory tests on every individual with a consistent clinical picture and a history of exposure (e. g. , chickenpox). Case definitions may also vary agree to the purpose for classifying the occurrences of a disease. For example, health officials need to know as soon as possible if anyone has symptoms of plague or foodborne botulism so that they can cast down planning what actions to take. For such rare but potentially severe dis eases, where it is important to identify every possible case, health officials use a sensitive, or loose case definition.On the other hand, investigators of the causes of a disease outbreak wish to be certain that any person include in the investigation really had the disease. The investigator will prefer a specific or strict case definition. For instance, in an outbreak of Salmonella agona, the investigators would be more likely to identify the source of the infection if they included only persons who were confirmed to have been infected with that organism, rather than including anyone with acute diarrhea, because some persons may have had diarrhea from a different cause. In this setting, a disadvantage of a strict case definition is an underestimate of the total number of cases. Exercise 1. 2In the case definition for an apparent outbreak of trichinosis, investigators used the following classifications Clinical criteria corroborate case signs and symptoms plus laboratory confirm ation Probable case acute onset of at least three of the following four features myalgia, fever, seventh cranial nerve edema, or eosinophil count greater than 500/mm3 Possible case acute onset of two of the above four features plus a physician diagnosis of trichinosis Suspect case unexplained eosinophilia Not a case failure to fulfill the criteria for a confirmed, probable, possible, or suspect case Time flak after October 26, 1991 Place Metropolitan battle of Atlanta Person Any Assign the appropriate classification to each of the persons included in the line listing below. (All were residents of Atlanta with acute onset of symptoms in November. ) Page 12 Applied Epidemiology I ID 1 2 3 4 5 Last name Abels Baker Corey Dale Ring myalgia yes yes yes yes yes fever yes yes yes no no facial edema no yes no no no eosinophil count 495 pending 1,100 2,050 600 Physician diagnosis trichinosis trichinosis ? trichinosis EMS ? trichinosis Lab confirm yes pending pending pending not done Class ification __________ __________ __________ __________ __________Exercise 1. 3 The following is the official case definition for Kawasaki syndrome that is recommended by CDC Kawasaki Syndrome Clinical case definition A febrile illness of greater than or equal to 5 age duration, with at least four of the five following bodily findings and no other more reasonable explanation for the observed clinical findings Bilateral conjunctival injection Oral changes (erythema of lips or oropharynx, strawberry tongue, or fissuring of the lips) Peripheral extremity changes (edema, erythema, or generalized or periungual desquamation) Rash cervical lymphadenopathy (at least one lymph node greater than or equal to 1. cm in diameter) Laboratory criteria for diagnosis None Case classification Confirmed a case that meets the clinical case definition Comment If fever disappears after intravenous gamma globulin therapy is started, fever may be of less than 5 days duration, and the clinical case defi nition may still be met. Source 3 Discuss the pros and cons of this case definition for the purposes listed below. (For a brief description of Kawasaki syndrome, see Benensons Control of Communicable Diseases in Man). a. Diagnosing and treating individual patients b. Tracking the occurrence of the disease for public health records c. Doing research to identify the cause of the disease Introduction to Epidemiology Epi 592J Page 13 Numbers and RisksA basic task of a health department is ascertain cases in order to measure and describe morbidity. When physicians diagnose a case of a reportable disease they are suppose to report the case to their local health department. For most reportable conditions, these reports are legally required to contain information on time (when the case occurred), place (where the patient lived), and person (the age, race, and sex of the patient). The health department combines all reports and summarizes the information by time, place, and person. From the se summaries, the health department determines the period and patterns of disease occurrence in the area, and attempts to identify clusters or outbreaks of disease.A simple count of cases, however, does not provide all the information a health department needs. To compare the occurrence of a disease at different locations, during different times, or in different subgroups, a health department converts the case counts into risks, which relates the number of cases to the size of the population. Risks are helpful in many ways. With risks, the health department can identify groups in the community with an elevated risk of disease. These so-called high-risk groups can be further assessed and targeted for special intervention the groups can be studied to identify risk factors that are related to the occurrence of disease.Individuals can use knowledge of these risk factors to guide their decisions about behaviors that influence health. Descriptive Epidemiology In descriptive epidemiology , we organize and summarize data according to time, place, and person. These three characteristics are sometimes called the epidemiologic variables. Compiling and analyzing data by time, place, and person is desirable for several reasons. First, the investigator becomes intimately familiar with the data and with the extent of the public health problem being investigated. Second, this provides a detailed description of the health of a population that is easily communicated. Third, such analysis identifies the populations at superlative risk of acquiring a particular disease.This information provides important clues to the causes of the disease, and these clues can be turned into testable hypotheses. Time (When? ) Disease risks usually change over time. Some of these changes occur regularly and can be predicted. For example, the seasonal increase of flu cases with the onset of cold weather is a pattern that is familiar to everyone. By knowing when flu outbreaks will occur, health de partments can time their grippe vaccination campaigns effectively. Other diseases may make unpredictable changes in occurrence. By examining events that precede a disease increase or decrease, we may identify causes and appropriate actions to control or prevent further occurrence of the disease.We usually show time data as a graph ( stick out 1. 3). We put the number or risk of cases or deaths on the vertical, y-axis we put the time periods along the crosswise, x-axis. We often indicate on a graph when events occurred that we believe are related to the particular health problem described in the graph. For example, we may indicate the period of exposure or the date control measures were implemented. Such a graph provides a simple visual delineation of the relative size of a problem, its past trend and potential approaching course, as well as how other events may have affected the problem. Studying such a graph often gives us insights into what may have caused the problem.Dependin g on what event we are describing, we may be interested in a period of years or decades, or we may limit the period to hours, days, weeks, or months when the number of cases reported is greater than normal (an epidemic period). For some conditionsfor many chronic diseases, for examplewe are interested in long-term changes in the number of cases or risk of the condition. For other conditions, we may find it more revealing to look at the occurrence of the condition by season, month, day of the Page 14 Applied Epidemiology I week, or even time of day. For a newly recognized problem, we need to assess the occurrence of the problem over time in a variety of ways until we discover the most appropriate and revealing time period to use. Some of the common types of time-related graphs are further described below. unsanctified (long-term) trends.Graphing the annual cases or risk of a disease over a period of years shows long-term or secular trends in the occurrence of the disease. We commonl y use these trends to suggest or predict the future incidence of a disease. We also use them in some instances to evaluate programs or policy decisions, or to suggest what caused an increase or decrease in the occurrence of a disease, particularly if the graph indicates when related events took place, as visualized in enroll 1. 3 (note the scale of the y-axis). find out 1. 3 Malaria by year, United States, 1930-1990 Works Progress Administration Malaria Control Drainage computer program Relapses from Overseas Cases 1000 Reported Cases per 100,000 Population 100Relapses from Korean Veterans Returning Vietnam Veterans 10 Foreign Immigration 1 0. 1 0. 01 1930 1935 1940 1945 1950 1955 1960 1965 1970 1975 1980 1985 1990 Source 9 social class Seasonality. By graphing the occurrence of a disease by week or month over the course of a year or more we can show its seasonal pattern, if any. Some diseases are known to have characteristic seasonal distributions for example, as mentioned ear lier, the number of reported cases of influenza typically increases in winter. Seasonal patterns may suggest hypotheses about how the infection is transmitted, which behavioral factors increase risk, and other possible contributors to the disease or condition.The seasonal pattern of an unknown disease is shown in Figure 1. 4. What factors might contribute to its seasonal pattern? From only the single years data in Figure 1. 4, it is difficult to conclude whether the peak in June represents a characteristic seasonal pattern that would be repeated yearly, or whether it is simply an epidemic that occurred in the spring and summer of that particular year. You would need more than one years data before you could conclude that the pattern shown there represents the seasonal variation in this disease. Introduction to Epidemiology Epi 592J Page 15 Figure 1. 4 Cases of an unknown disease by month of onset 450 400 350 300 Cases 50 200 150 100 50 0 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Source 14 calendar month of Onset Day of week and time of day. Displaying data by days of the week or time of day may also be informative. Analysis at these shorter time periods is especially important for conditions that are potentially related to occupational or environmental exposures, which may occur at regularly scheduled time intervals. In Figure 1. 5, farm tractor fatalities are displayed by days of the week. Does this analysis at shorter time periods suggest any hypothesis? In Figure 1. 5 the number of farm tractor fatalities on Sundays is about half the number on the other days. We can only ponder why this is.One reasonable hypothesis is that farmers spend fewer hours on their tractors on Sundays than on the other days. Figure 1. 5 Fatalities associated with farm tractor injuries by day of death, Georgia, 1971-1981 Source 15 Page 16 Applied Epidemiology I dig into the pattern of fatalities associated with farm tractor injuries by hour in Figure 1. 6. How might you ex plain the morning peak at 1100 AM, the dip at noon, and the afternoon peak at 400 PM? Figure 1. 6 Fatalities associated with farm tractor injuries by time of day, Georgia, 1971-1981 Source 15 Epidemic period. To show the time course of a disease outbreak or epidemic, we use a graph called an epidemic curve.As with the other graphs you have seen in this section, we place the number of cases on the vertical axis and time on the horizontal axis. For time, we use either the time of onset of symptoms or the date of diagnosis. For very acute diseases with short incubation periods (i. e. , time period between exposure and onset of symptoms is short), we may show time as the hour of onset. For diseases with longer incubation periods, we might show time in 1-day, 2-day, 3-day, 1-week, or other appropriate intervals. Figure 1. 7 shows an epidemic curve that uses a 3-day interval for a foodborne disease outbreak. Notice how the cases are stacked in nigh columns. By convention, we use this fo rmat, called a histogram, for epidemic curves.The shape and other features of an epidemic curve can suggest hypotheses about the time and source of exposure, the mode of transmission, and the causative agent. Figure 1. 7 Date of onset of illness in patients with culture-confirmed Yersinia enterocolitica infections, Atlanta, November 1, 1988-January 10, 1989 8 7 6 Thanksgiving Christmas New Years Cases 5 4 3 2 1 0 1 4 7 10 13 16 19 22 25 28 1 4 7 10 13 16 19 22 25 28 1 4 7 10 November December January Source 18 Date of Onset Introduction to Epidemiology Epi 592J Page 17 Place (Where? ) We describe a health event by place to gain insight into the geographical extent of the problem. For place, we may use place of residence, birthplace, employment, school district, hospital unit, etc. , epending on which may be related to the occurrence of the health event. Similarly, we may use large or small geographic units coun deliver, state, county, census tract, street address, map coordinates, or some other geographical designation. Sometimes, we may find it expedient to test data according to place categories such as urban or rural, domestic or foreign, and institutional or noninstitutional. Not all analyses by place will be equally informative. For example, examine the data shown in Table 1. 3. Where were the malaria cases diagnosed? What place does the table break the data down by? Would it have been more or less usable to analyze the data according to the state of residence of the cases?We believe that it provides more useful information to show the data in Table 1. 3 by where the infection was acquired than it would have to show where the case-patients lived. By analyzing the malaria cases by place of acquisition, we can see where most of the malaria cases acquired their disease. Table 1. 3 Malaria cases by distribution of plasmodium species and area of acquisition, United States, 1989 Species Area of Acquisition Vivax Falciparum Other jibe Africa 52 382 64 498 Asia 207 44 29 280 Central America &038 Caribbean 107 14 9 130 North America 131 3 13 147 (United States) (5) (0) (0) (5) South America 10 1 2 13 Oceania 19 2 5 26 Unknown 6 2 0 8 Total 532 448 122 1,102 Source 6By analyzing data by place, we can also get an conception of where the agent that causes a disease normally lives and multiplies, what may carry or transmit it, and how it spreads. When we find that the occurrence of a disease is associated with a place, we can infer that factors that increase the risk of the disease are present either in the persons living there (host factors) or in the environment, or both. For example, diseases that are passed from one person to another tend to spread more promptly in urban areas than in rural ones, mainly because the greater move in urban areas provides more opportunities for susceptible people to come into speck with someone who is infected.On the other hand, diseases that are passed from animals to humans often occur in greater num bers in rural and suburban areas because people in those areas are more likely to come into contact with disease-carrying animals, ticks, and the like. For example, perhaps Lyme disease has become more common because people have moved to thicket-forming areas where they come into contact with infected deer ticks. Although we can show data by place in a tableas Table 1. 3 doesit is often better to show it pictorially in a map. On a map, we can use different shadings, color, or line patterns to indicate how a disease or health event has different numbers or risks of occurrence in different areas, as in Figure 1. 8. Page 18 Applied Epidemiology I Figure 1. 8 AIDS cases per 100,000 population, United States, July 1991-June 1992 Source 4For a rare disease or outbreak, we often find it useful to prepare a spot map, like Snows map of the Golden Square of London (Figure 1. 1), in which we mark with a dot or an X the relation of each case to a place that is potentially relevant to the healt h event being investigatedsuch as where each case lived or worked. We may also label other sites on a spot map, such as where we believe cases may have been exposed, to show the orientation of cases within the area mapped. Figure 1. 9 is a spot map for an outbreak of mumps that occurred among employees of the Chicago futures exchanges. Study the location of each case in relation to other cases and to the craft pits. The four numbered areas delineated with telling lines are the trading pits.Does the location of cases on the spot map lead you to any hypothesis about the source of infection? Figure 1. 9 epidemic parotitis cases in trading pits of exchange A, Chicago, Illinois, August 18-December 25, 1987 1 3 2 4 Key Pit areas are numbered and delineated by heavy lines. Individual trading pits within pit areas are outlined by light lines. Affected person (N= 43) Desk areas Source CDC, unpublished data, 1988 Introduction to Epidemiology Epi 592J Page 19 You probably observed that the cases occurred primarily among those working in trading pits 3 and 4. This clustering of illness within trading pits provides indirect evidence that the mumps was transmitted person-to person. Person (Who? ) In descriptive epidemiology, when we organize or analyze data by person there are several person categories available to us. We may use inherent characteristics of people (for example, age, race, sex), their acquired characteristics (immune or marital status), their activities (occupation, leisure activities, use of medications/tobacco/drugs), or the conditions under which they live (socioeconomic status, access to medical care). These categories usually determine, to a large degree, who is at sterling(prenominal) risk of experiencing certain undesirable health conditions, such as fair infected with a particular disease organism. We may show person-related characteristics in either tables or graphs.In analyzing data by person, we often must try a number of different categorie s before we find which are the most useful and enlightening. get along and sex are most critical we almost always analyze data according to these. Depending on the health event we are studying, we may or may not break the data down by other attributes. Often we analyze data by more than one characteristic simultaneously for example, we may look at age and sex simultaneously to see if the sexes differ in how they develop a condition that increases with agesuch as with heart disease. Age. Age is probably the single most important person attribute, because almost every health-related event or state varies with age.A number of factors that also vary with age are behind this association power, opportunity for exposure, latency or incubation period of the disease, and physiologic response (which affects, among other things, disease development). When we analyze data by age, we try to use age groups that are narrow enough to detect any agerelated patterns that may be present in the data. In an initial breakdown by age, we commonly use 5-year age intervals 0 to 4 years, 5 to 9, 10 to 14, and so on. Larger intervals, such as 0 to 19 years, 20 to 39, etc. , may conceal variations related to age which we need to know to identify the true ages at greatest risk.Sometimes, even 5-year age groups can hide important differences, especially in children less than five years of age. Take time to examine Figure 1. 10, for example, before you read ahead. What does the information in this figure suggest health authorities should do to reduce the number of cases of whooping cough? Where should health authorities focus their efforts? You probably said that health authorities should focus on immunizing infants against whooping cough during the first year of life. Now, examine Figure 1. 11. This figure shows the same data but they are presented in the usual 5-year intervals. Based on Figure 1. 11 where would you have suggested that health authorities focus their efforts?Would this r ecommendation have been as effective and efficient in reducing cases of whooping cough? You probably said that health authorities should immunize infants and children before the age of 5. That recommendation would be effective, but it would not be efficient. You would be immunizing more children than actually necessary and wasting resources. Sex. In general, males have higher risks of illness and death than females do for a wide range of diseases. For some diseases, this sex-related difference is because of genetic, hormonal, anatomic, or other inherent differences between the sexes. These inherent differences affect their susceptibility or physiologic responses.For example, premenopausal women have a lower risk of heart disease than men of the same age. This difference is attributed to higher estrogen levels in women. On the other hand, the sex-related differences in the occurrence of many diseases reflect differences in opportunity or levels of exposure. For example, Figure 1. 12 shows that hand/ radiocarpal joint joint disorders occur almost twice as often in females than in males. What are some sex-related differences that would cause a higher level of this disorder in females? Page 20 Applied Epidemiology I Figure 1. 10 Pertussis (whooping cough) incidence by age group, United States, 1989 Source 9 Figure 1. 11 Pertussis (whooping cough) incidence by age group, United States, 1989 Source 9 Figure 1. 2 Prevalence of hand/ carpus cumulative trauma disorder by sex, Newspaper Company A, 1990 Source NIOSH, unpublished data, 1991 Introduction to Epidemiology Epi 592J Page 21 You may have attributed the higher level of disorders in females to their higher level of exposure to occupational activities that require repetitive hand/wrist motion such as write or keyboard entry. With occupationally-related illness, we usually find that sex differences reflect the number of workers in those occupations. You may also have attributed the higher level of disorders in f emales to anatomical differences perhaps womens wrists are more susceptible to hand/wrist disorders. Ethnic and racial groups.In examining epidemiologic data, we are interested in any group of people who have lived together long enough to acquire common characteristics, either biologically or socially. Several terms are commonly used to identify such groups race, nationality, religion, or local productive or social groups, such as tribes and other geographically or socially isolated groups. Differences that we observe in racial, ethnic, or other groups may reflect differences in their susceptibility or in their exposure, or they may reflect differences in other factors that bear more directly on the risk of disease, such as socioeconomic status and access to health care. In Figure 1. 13, the risks of suicide for five groups of people are displayed. Figure 1. 3 Suicide death rates for persons 15 to 24 years of age according to race/ethnicity, United States, 1988 Source 22 understan dably this graph displays a range of suicide death rates for the five groups of people. These data provide direction for prevention programs and for future studies to explain the differences. socioeconomic status. Socioeconomic status is difficult to quantify. It is made up of many variables such as occupation, family income, educational achievement, living conditions, and social standing. The variables that are easiest to measure may not reflect the overall concept. Nevertheless, we commonly use occupation, family income, and educational achievement, while recognizing that these do not measure socioeconomic status precisely.The frequency of many adverse health conditions increases with decreasing socioeconomic status. For example, tuberculosis is more common among persons in lower socioeconomic strata. Infant mortality and time muddled from work due to disability are both associated with lower income. These patterns may reflect more harmful exposures, lower resistance, and less ac cess to health care. Or they may in part Page 22 Applied Epidemiology I reflect an interdependent relationship which is impossible to untangledoes low socioeconomic status contribute to disability or does disability contribute to lower socioeconomic status? Some adverse health conditions are more frequent among persons of higher socioeconomic status.These conditions include breast cancer, Kawasaki syndrome, and tennis elbow. Again, differences in exposure account for at least some of the differences in the frequency of these conditions. Exercise 1. 4 The following series of tables (Exercise 1. 4, Tables 1-4) show person information about cases of the unknown disease described in Figure 1. 4 on page 15. Look again at Figure 1. 4, study the information in the four exercise tables and then describe in words how the disease outbreak is distributed by time and person. Exercise 1. 4, Table 1 Incidence of the disease by age and sex in 24 villages surveyed for one year Males Females Age Gro up Population* Cases Risk per Population* Cases Risk per (years) 1,000 1,000