2015年1月10日
第一篇：疾病的三个历史阶段
主要内容：第一个传染阶段，主要是由于医疗差，人口发展，开始农业，人与人，以及动物之间的接触越来越多，疾病开始大规模的传染。第二，医疗得以发展，传染病被克服，但是由于经济的发展，生活水平不断上升，慢性病开始占据主导地位，比如心脏病，肺结核等。第三，到了现代社会，传染病重新出现，慢性病也没有被克服，细菌产生了抗力，很多以前没有出现的疾病开始出现了。
TPO相似文章练习推荐： TPO 16：Developmentof The Periodic Table
背景资料：
Only some diseases such as influenza are contagious and commonly believedinfectious. The micro-organisms that cause these diseases are known aspathogens and include varieties of bacteria, viruses, protozoa and fungi. Infectious diseases can be transmitted, e.g. byhand-to-mouth contact with infectious material on surfaces, by bites of insects or other carriers of the disease, and from contaminatedwater or food (often via fecal contamination), etc. In addition,there are sexually transmitteddiseases. In some cases, microorganisms that are not readily spread fromperson to person play a role, while other diseases can be prevented orameliorated with appropriate nutrition or other lifestyle changes. Somediseases, such as most (but not all) forms of cancer, heart disease, and mental disorders,are non-infectious diseases. Manynon-infectious diseases have a partly or completely genetic basis (see genetic disorder) and may thus betransmitted from one generation to another. Social determinants of health are the social conditions in whichpeople live that determine their health. Illnesses are generally related tosocial, economic, political, and environmentalcircumstances. Social determinants of health have been recognized by severalhealth organizations such as the Public Health Agency of Canada and the World Health Organization togreatly influence collective and personal well-being. The World HealthOrganization's Social Determinants Council also recognizes Social determinants of health inpoverty. When the cause of a disease is poorly understood, societies tend tomythologize the disease or use it as a metaphor or symbol of whatever that cultureconsiders evil. For example, until the bacterial cause of tuberculosis was discovered in 1882, expertsvariously ascribed the disease to heredity,a sedentary lifestyle, depressedmood, and overindulgence in sex, rich food, or alcohol—all the social ills of the time.
Disease burden is the impact of a health problem inan area measured by financial cost, mortality, morbidity, or other indicators.There are several measures used to quantify the burden imposed by diseases onpeople. The years of potentiallife lost (YPLL) is a simple estimate of the number of years that a person'slife was shortened due to a disease. For example, if a person dies at the ageof 65 from a disease, and would probably have lived until age 80 without thatdisease, then that disease has caused a loss of 15 years of potential life.YPLL measurements do not account for how disabled a person is before dying, sothe measurement treats a person who dies suddenly and a person who died at thesame age after decades of illness as equivalent. In 2004, the World HealthOrganization calculated that 932million years of potential life were lost to premature death. The quality-adjusted life year (QALY) and disability-adjusted life year (DALY) metrics are similar, but takeinto account whether the person was healthy after diagnosis. In addition to thenumber of years lost due to premature death, these measurements add part of theyears lost to being sick. Unlike YPLL, these measurements show the burdenimposed on people who are very sick, but who live a normal lifespan. A diseasethat has high morbidity, but low mortality, has a high DALY and a low YPLL. In2004, the World Health Organization calculated that 1.5 billiondisability-adjusted life years were lost to disease and injury. Inthe developed world, heartdisease and stroke cause the most loss of life, but neuropsychiatric conditions like majordepressive disorder cause themost years lost to being sick.
第二篇：手工工艺的衰落
主要内容：16世纪，artisans的繁荣发展被削弱，一些技术的发展使得成本上升，手工艺人无法承担，原料的买卖大权掌握在大商人手中，穷的手工艺人只能依靠便宜的当地材料，很多独立的生产者沦落为大商人的employee。同时他们又担心乡下地区的发展，因为那里成本消费更低，更好招人。
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背景补充：
Before 1815manufacturing in the United States had been done in homes or shops by skilledartisans. As master craft workers, they imparted theknowledge of their trades to apprentices and journeymen. In addition, womenoften worked in their homes part-time, making finished articles from rawmaterial supplied by merchant capitalists. After 1815 this older form ofmanufacturing began to give way to factories with machinery tended by unskilledor semiskilled laborers. Cheap transportation networks, the rise of cities, andthe availability of capital and credit all stimulated the shift to factoryproduction.
The creationof a labor force that was accustomed to working in factories did not occureasily. Before the rise of the factory, artisans had worked within the home.Apprentices were considered part of the family, and masters were responsiblenot only for teaching their apprentices a trade but also for providing themsome education and for supervising their moral behavior. Journeymen knew thatif they perfected their skill, they could become respected master artisans withtheir own shops. Also, skilled artisans did not work by the clock, at a steadypace, but rather in bursts of intense labor alternating with more leisurelytime.
The factorychanged that. Goods produced by factories were not as finished or elegant asthose done by hand, and pride in craftsmanship gave way to the pressure toincrease rates of productivity. The new methods of doing business involved anew and stricter sense of time. Factory life necessitated a more regimentedschedule, where work began at the sound of a bell and workers kept machinesgoing at a constant pace. At the same time, workers were required to discardold habits, for industrialism demanded a worker who was alert, dependable, andself-disciplined. Absenteeism and lateness hurt productivity and, since workwas specialized, disrupted the regular factory routine. Industrialization notonly produced a fundamental change in the way work was organized; ittransformed the very nature of work.
The firstgeneration to experience these changes did not adopt the new attitudes easily.The factory clock became the symbol of the new work rules. One mill worker whofinally quit complained revealingly about "obedience to the ding-dong ofthe bell-just as though we are so many living machines." With the loss ofpersonal freedom also came the loss of standing in the community. Unlikeartisan workshops in which apprentices worked closely with the masterssupervising them, factories sharply separated workers from management. Fewworkers rose through the ranks to supervisory positions, and even fewer couldachieve the artisan's dream of setting up one's own business. Even well-paidworkers sensed their decline in status.
In this newlyemerging economic order, workers sometimes organized to protect their rightsand traditional ways of life. Craft workers such as carpenters, printers, andtailors formed unions, and in 1834 individual unions came together in theNational Trades' Union. The labor movement gathered some momentum in the decadebefore the Panic of 1837, but in the depression that followed, labor's strengthcollapsed. During hard times, few workers were willing to strike* or engage in collective action. And skilled craft workers,who spearheaded the union movement, did not feel a particularly strong bondwith semiskilled factory workers and unskilled laborers. More than a decade ofagitation did finally bring a workday shortened to 10 hours to most industriesby the 1850’s, and the courts also recognized workers' right to strike, butthese gains had little immediate impact.
Workers wereunited in resenting the industrial system and their loss of status, but theywere divided by ethnic and racial antagonisms, gender, conflicting religiousperspectives, occupational differences, political party loyalties, anddisagreements over tactics. For them, the factory and industrialism were notagents of opportunity but reminders of their loss of independence and a measureof control over their lives. As United States society became more specializedand differentiated, greater extremes of wealth began to appear. And as the newmarkets created fortunes for the few, the factory system lowered the wages ofworkers by dividing labor into smaller, less skilled tasks.
第三篇：大气中的氧气含量
主要内容：大气中最初是没有氧气的，因为光合作用和火山爆发而慢慢变化，水蒸气产生大量氧气，然后开始出现了生物。通过和太阳比较，现在空气中比以前少了些元素，氧气的产生过程中，水分解放出氧，植物进行转化。研究发现氧先和铁结合进入海洋，因为两个时间点的石头构成不同，生物爆发正好与后一个时间点重合，氧气含量还与decompose有关。
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背景补充：
Oxygen is an importantpart of the atmosphere, and is necessary to sustain most terrestrial life as itis used in respiration. However, it is too chemically reactive to remain a freeelement in Earth's atmosphere without being continuously replenishedby the photosynthetic action of living organisms, which usethe energy of sunlight to produce elemental oxygen from water. Another form(allotrope) of oxygen, ozone (O3),strongly absorbs UVB radiation and consequently thehigh-altitude ozone layer helps protect the biosphere from ultraviolet radiation, but is apollutant near the surface where it is a by-product of smog. At even higher low earth orbit altitudes, atomic oxygen is asignificant presence and a cause of erosionfor spacecraft. Oxygen is produced industrially by fractional distillation of liquefied air, use of zeolites with pressure-cycling to concentrate oxygen from air,electrolysis of water and othermeans. Uses of elemental oxygen include the production of steel, plastics and textiles, brazing, welding and cutting of steels and other metals, rocket propellant, oxygen therapy and lifesupport systems in aircraft, submarines, spaceflight and diving.
Free oxygen gas was almost nonexistent in Earth's atmosphere before photosynthetic archaea and bacteriaevolved, probably about 3.5 billion years ago. Free oxygen first appeared insignificant quantities during the Paleoproterozoic eon (between 3.0 and 2.3 billion yearsago). For the first billion years, any free oxygen produced by theseorganisms combined with dissolved iron in the oceans to form banded iron formations. When suchoxygen sinks became saturated, free oxygen began to outgas from the oceans3–2.7 billion years ago, reaching 10% of its present level around1.7 billion years ago. The presence of large amounts of dissolved and freeoxygen in the oceans and atmosphere may have driven most of the anaerobic organisms then living to extinction during the Great Oxygenation Event (oxygen catastrophe) about 2.4billion years ago. However, cellularrespiration using O2 enables aerobic organisms to produce much moreATP than anaerobic organisms, helping the former to dominate Earth's biosphere. Cellular respiration of O2 occurs in all eukaryotes, including all complexmulticellular organisms such as plants and animals. Since the beginning of the Cambrian period 540 million years ago, O2 levels have fluctuated between 15% and30% by volume. Towards the end of the Carboniferous period (about 300 million yearsago) atmospheric O2 levelsreached a maximum of 35% by volume, which may have contributed tothe large size of insects and amphibians at this time. Human activities, including theburning of 7 billion tonnes of fossilfuels each year have had verylittle effect on the amount of free oxygen in the atmosphere. At the current rate of photosynthesisit would take about 2,000 years to regenerate the entire O2 in the present atmosphere.
(编辑：Kitty)