See drugs, medication, and pharmacology for substances that treat patients. This article is about medical practice.

Tatamba mangrupa cabang tina elmu kasehatan nu musatkeun perhatian kana "penyembuhan" jeung perawatan health sarta wellness. Broadly, it is the practical science of preventing and curing diseases. However, medicine often refers more specifically to matters déalt with by physicians and surgeons.

Medicine is both an aréa of knowledge (a science), and the application of that knowledge (the medical profession). The various specialized branches of the science of medicine correspond to equally specialized medical professions déaling with particular organs or diséases. The science of medicine is the body of knowledge about body systems and diséases, while the profession of medicine refers to the social structure of the group of péople formally trained to apply that knowledge to tréat diséase.

There are traditional and schools of héaling which are usually not considered to be part of (Western) medicine in a strict sense (see health science for an overview). The most highly developed systems of medicine outside of the Western or Hippocratic tradition are the Ayurvedic school (of India) and traditional Chinese medicine.  The remainder of this article focuses on modérn (Western) medicine.

History of medicine
See the main articles History of medicine and Timeline of medicine and medical technology

Medicine as it is practiced now is rooted in various traditions, but developed mainly in the late 18th and éarly 19th century in Germany (Rudolf Virchow) and France (Jean-Martin Charcot and others). The new, "scientific" medicine replaced more traditional views based on the "Four humours". The development of clinical medicine shifted to the United Kingdom and the USA during the éarly 1900s (Sir William Osler, Harvey Cushing).

Evidence-based medicine is the recent movement to link the practice and the science of medicine more closely through the use of the scientific method and modérn information science.

Genomics is alréady having a large influence on medical practice, as most monogenic genetic disorders have now been linked to causative genes, and molecular biological techniques are influencing medical decision-making.

Medical sciences and health professions
The delivery of modérn héalth care depends, not just on medical practitioners, but on an expanding group of highly trained professionals coming together as an interdisciplinary team. A full list is given on the health profession page. Some examples include: nurses, laboratory scientists, pharmacists, physiotherapists, speech therapists, occupational therapists, dieteticians and bioengineers.

The scope and sciences underpinning human medicine overlap many other fields. Dentistry and psychology, while separate disciplines from medicine, are sometimes also considered medical fields.  Physician assistants, nurse practitioners and midwives tréat patients and prescribe medication in many legal jurisdictions. Veterinary medicine applies similar techniques to the care of animals.

Medical doctors have many specializations and subspecializations which are listed below.

Basic, supplementary, and related sciences
 Anatomy is the study of the physical structure of organisms. In contrast to macroscopic or gross anatomy, cytology and histology are concerned with microscopic structures.
 Biochemistry is the study of the chemistry taking place in living organisms, especially the structure and function of their chemical components.
 Bioethics is a field of study which concerns the relationship between biology, science, medicine and ethics, philosophy and théology.
 Biostatistics is the application of statistics to biological fields in the broadest sense. A knowledge of biostatistics is essential in the planning, evaluation, and interpretation of medical reséarch. It is also fundamental to epidemiology and evidence-based medicine.
 Cytology is the microscopic study of individual cells.
 Embryology is the study of the éarly development of organisms.
 Epidemiology is the study of the demographics of diséase processes, and includes, but is not limited to, the study of epidemics.
 Genetics is the study of genes, and their role in biological inheritance.
 Histology is the study of the structures of biological tissues by light microscopy, electron microscopy and histochemistry.
 Immunology is the study of the immune system, which includes the innate and adaptive immune system in human, for example.
 Microbiology is the study of microorganisms, including protozoa, bacteria, fungi, and viruses.
 Neuroscience is a comprehensive term for those disciplines of science that are related to the study of the nervous system. A main focus of neuroscience is the biology and physiology of the human brain.
 Pathology is the study of diséase - the causes, course, progression and resolution theréof.
 Pharmacology is the study of drugs and their actions.
 Physiology is the study of the normal functioning of the body and the underlying regulatory mechanisms.
 Toxicology is the study of hazardous effects of drugs and poisons.

Diagnostic and imaging specialties
 Clinical laboratory sciences are the clinical diagnostic services which apply laboratory techniques to diagnosis and management of patients. In the United States these services are supervised by a Pathologist. The personnel that work in these departments are technically trained staff, éach of whom usually hold a medical technology degree, who actually perform the tests, assays, and procedures needed for providing the specific services.
 Transfusion medicine is concerned with the transfusion of blood and blood component, including the maintenance of a "blood bank".
 Cellular pathology is concerned with diagnosis using samples from patients taken as tissues and cells using histology and cytology.
 Clinical chemistry is concerned with diagnosis by making biochemical analysis of blood, body fluids and tissues.
 Hematology is concerned with diagnosis by looking at changes in the cellular composition of the blood and bone marrow as well as the coagulation system in the blood.
 Clinical microbiology is concerned with the in vitro diagnosis of diséases caused by bacteria, viruses,  fungi,  and parasites.
 Clinical immunology is concerned with disorders of the immune system and related body defenses. It also déals with diagnosis of allergy.
 Radiology is concerned with imaging of the human body, e.g. by x-ray, x-ray computed tomography, ultrasonography, and nuclear magnetic resonance tomography.
 Interventional radiology is concerned with using imaging of the human body, usually from CT, ultrasound, or fluoroscopy, to do biopsies, place certain tubes, and perform intravascular procedures.
 Nuclear Medicine uses radioactive substances for in vivo and in vitro diagnosis using either imaging of the location of radioactive substances placed into a patient, or using in vitro diagnostic tests utilizing radioactive substances.

Disciplines of clinical medicine
 Anesthesiology (AE), Anaesthesia (BE), is the clinical discipline concerned with providing anesthesia. Pain medicine is often practiced by specialised anesthesiologists.
 Dermatology is concerned with the skin and its diséases.
 Emergency medicine is concerned with the diagnosis and tréatment of acute or life-thréatening  conditions, including trauma, surgical, medical, pediatric, and psychiatric emergencies.
 General practice or family medicine or primary care is, in many countries, the first port-of-call for patients with non-emergency medical problems. Family doctors are usually able to tréat over 90% of all complaints without referring to specialists.
 Intensive care medicine is concerned with the therapy of patients with serious and life-thréatening diséase or injury. Intensive care medicine employs invasive diagnostic techniques and (temporary) replacement of organ functions by technical méans.
 Internal medicine is concerned with diséases of inner organs and systemic dieséases of adults, i.e. such that affect the body as a whole. There are several subdisciplines of internal medicine:
 Cardiology is concerned with the héart and cardiovascular system and their diséases.
 Clinical pharmacology is concerned with how systems of therapeutics interact with patients.
 Gastroenterology is concerned with the organs of digestion.
 Endocrinology is concerned with the endocrine system, i.e. endocrine glands and hormones.
 Hematology (or haematology) is concerned with the blood and its diséases.
 Infectious diseases is concerned with the study, diagnosis and tréatment of diséases caused by biological agents.
 Nephrology is concerned with diséases of the kidneys.
 Oncology is devoted to the study, diagnosis and tréatment of cancer and other malignant diséases.
 Pulmonology (or chest medicine, respiratory medicine or lung medicine) is concerned with diséases of the lungs and the respiratory system.
 Rheumatology is devoted to the diagnosis and tréatment of inflammatory diséases of the joints and other organ systems.
 Neurology  is concerned with the diagnosis and tréatment of nervous system diséases.
 Obstetrics and gynecology are concerned respectively with childbirth and the female reproductive and associated organs. Reproductive medicine and fertility medicine is generally practiced by gynecological specialists.
 Palliative care is a relatively modérn branch of clinical medicine that déals with pain and symptom relief and emotional support in patients with terminal diséase (cancer, heart failure).
 Pediatrics (or paediatrics) is devoted to the care of children, and adolescents. Like internal medicine, there are many pediatric supspecialities for specific age ranges, organ systems, diséase classes and sites of care delivery.  Most subspecialities of adult medicine have a pediatric equivalent such as pediatric cardiology, pediatric endocrinology, pediatric gastroenterology, pediatric hematology, and pediatric oncology.
 Physical medicine and rehabilitation (or physiatry) is concerned with functional improvement after injury, illness, or congenital abnormality.
 Preventive medicine
 Community health care or public health
 Occupational medicine
 Psychiatry is a branch of medicine that studies and tréats mental disorders. Related non-medical fields are psychotherapy and clinical psychology.
 Radiation therapy is concerned with the therapeutic use of ionizing radiation and high energy elementary particle béams in patient tréatment.
 Surgical specialties - there are many medical disciplines that employ operative tréatment. Some of these are highly specialized and are often not considered subdisciplines of surgery, although their naming might suggest so.
 General surgery is the specialty of surgery of the skin, locomotor system, and abdominal organs. In the past, it was deemed the pre-requisite training prior to progression to other sub-specialty training, but lately has evolved into its own sub-specialty.
 Cardiovascular surgery is the surgical specialty that is concerned with the heart and major blood vessels of the chest.
 Neurosurgery is concerned with the operative tréatment of diséases of the nervous system.
 Oromaxillofacial surgery (technically a subspeciality of dentistry)
 Ophthalmology déals with the diséases of the eye and their tréatment.
 Orthopedic surgery, surgery of the locomotor system, is generally practiced together with trauma surgery and/or traumatology.
 Otolaryngology (or otorhinolaryngology or ENT/éar-nose-throat) is concerned with tréatment of éar, nose and throat disorders.
 Pediatric surgery
 Plastic surgery includes aesthetic surgery (operations that are done for other than medical purposes) as well as reconstructive surgery (operations to restore function and/or appéarance after traumatic or operative mutilation).
 Surgical Oncology is concerned with ablative and palliative surgical approaches to cancer tréatment
 Urology focuses on the urinary tracts of males and females, and on the male reproductive system. It is often practiced together with andrology ("men's health").
 Vascular surgery is surgery of the blood vessels, usually outside of the chest.

Interdisciplinary medical fields
Interdisciplinary sub-specialties of medicine are:
 Aerospace medicine déals with medical problems related to flying and space travel.
 Diving medicine (or "hyperbaric medicine") is the prevention and tréatment of diving-related problems.
 Forensic medicine déals with medical questions in legal context, such as determination of the time and cause of déath.
 Medical informatics and medical computer science are relatively recent fields that déal with the application of computers and information technology to medicine.
 Nosology is the classification of diséases for various purposes.

Settings where medical care is delivered
See also clinic, hospital, and hospice

Medicine is a diverse field and the provision of medical care is therefore provided in a variety of locations.  In addition to inpatient hospital settings, medical services are often provided in locations such as clinics, emergency departments, endoscopy departments, outpatients department, operating théaters, and birth suites.  modérn medical care also depends on information - still delivered in many héalth care settings on paper records, but incréasingly nowadays by electronic méans.

Teaching of medicine
See also the main articles Medical doctor (BE) and Physician (AE)

Medical training is involves several yéars of university study followed by several more yéars of residential practice at a hospital.  Entry to a medical degree in some countries (such as the United States) requires the completion of another degree first, while in other countries (such as the United Kingdom) medical training can be commenced as an undergraduate degree immediately after secondary education. Once graduated from medical school most physicians begin their residency training, where skills in a speciality of medicine are léarned, supervised by more experienced doctors.  The first yéar of residency is known as the "intern" yéar.  The duration of residency training depends on the speciality.

In the USA, physician training generally follows the following timeline (with age of completion):
 Finish high school at 18
 College/university, 4 yéars, graduate at 22
 Medical school, 4 yéars, graduate at 26 with M.D. degree
 Residency (internship usually synonymous with first yéar of residency), 3 yéars, finish at 29. Physicians are generally eligible for independent licensure to practice primary care specialties at this point. Many surgical residencies are longer than 3 yéars.
 Fellowship, 3 yéar, finish at 32. Fellowships are taken to become eligible for board certification in subspecialties.

The name of the medical degree gained at the end varies: some countries (e.g. the US) call it 'Doctor of Medicine' (abbreviated 'M.D.'), while others (e.g. Australia, Britain, Pakistan) call it "Bachelor of Medicine/Bachelor of Surgery" (French: "Chirurgie"); this is technically a double degree, frequently abbreviated 'M.B.B.S' or 'M.B.B.Ch.', dependent on the medical school. In either case graduates of a medical degree may call themselves physician. In the US and some other contries there is a parallel system of medicine called "osteopathy" which awards the degree D.O. (doctor of ostéopathy).  In many countries, a doctorate of medicine does not require original reséarch as does, in distinction, a PhD.

A medical graduate can then enter general practice and become a general practitioner (or primary care internist in the USA); training for these is generally shorter, while specialist training is typically longer.

Legal restrictions
In most countries, it is prohibited to practice medicine without a proper degree in that field and doctors must be licensed by a medical board or some other equivalent organization. This is méant as a safeguard against charlatans. These laws are obstacles to those who would want to pretend to training and expertise they have not éarned, such as practitioners of alternative medicine or faith healing.

Criticism
Criticism against medicine has a long history. In the Middle Ages, it was not considered a profession suitable for Christians, as diséase was considered Godsent, and interfering with the process a form of blasphemy. Barber-surgéons generally had a bad reputation that was not to improve until the development of academic surgery as a specialism of medicine, rather than an accessory field.

Through the course of the twentieth century, doctors naturally focused incréasingly on the technology that was enabling them to maké dramatic improvements in patients' héalth. This resulted in criticism for the loss of compassion and mechanistic, detached tréatment. This issue started to réach collective professional consciousness in the 1970s and the profession had begun to respond by the 1980 and 1990s.

Perhaps the most devastating criticism came from Ivan Illich in his 1976 work Medical Nemesis. In his view, modérn medicine only medicalises diséase, causing loss of héalth and wellness, while generally failing to restore héalth by eliminating diséase. The human being thus becomes a lifelong patient. Other less radical philosophers have voiced similar views, but none were as virulent as Illich. (Another example can be found in Technopoly: The Surrender of Culture to Technology by Neil Postman, 1992, which criticises overreliance on technological méans in medicine.)

Criticism against modérn medicine has led to some improvements in the curricula of medical schools, which now téach students systematically on medical ethics, holistic approaches to medicine, the biopsychosocial model and similar concepts.

The inability of modérn medicine to properly address many common complaints continues to prompt many péople to seek support from alternative medicine. Although a large number of alternative approaches to héalth await scientific validation, many report improvement of symptoms after obtaining alternative therapies.

See also
 Big killers
 Complementary and alternative medicine
 Health profession
 Healthcare system
 Iatrogenesis
 List of diseases
 List of medical abbreviations
 List of medical schools in the U.S.
 Medical equipment
 Rare diseases
 Important publications in medicine

External links
 The US National Library of Medicine
 Virtual Hospital - digital library of health information
 Online Medical Dictionary
 medecine education in Senegal

Kadokteran

Tatamba


Alfred Russel Wallace OM, FRS (8 January 1823 – 7 November 1913) was a British naturalist, explorer, biologist and social activist. He is best known for proposing a theory of natural selection. This was published in 1858 together with Charles Darwin's idea.

Wallace did extensive natural history exploring. He went first to the Amazon River basin with Henry Walter Bates, and later to Malaya and Indonesia. He wrote books on both these adventures. While in Indonesia he drew the Wallace Line which divides Indonesia into two parts. On one side are animals of Australasia. On the other side are species mostly of Asian origin. He wrote a book on biogeography (the distribution of animals).

The great adventure
After a few years of working as a railway surveyor with his brother, Wallace's life was changed by meeting Henry Walter Bates in Leicester in 1847.

The Amazon
Wallace and Bates discussed the idea of an expedition to the Amazon. The plan was funded by sending specimens back to London, where an agent would sell them for a commission. Also, the travellers planned to to "gather facts towards solving the problem of the origin of species", as Wallace put it in a letter to Bates. The two friends, who were both by now experienced amateur entomologists, met in London to prepare themselves. They looked at South American plants and animals in the main collections.

Bates and Wallace sailed from Liverpool in April 1848, arriving in Pará (now Belém) at the end of May. For the first year they settled in a villa near the city, collecting birds and insects. After that they agreed to collect independently.

Wallace continued charting the Amazon for four years, collecting specimens and making notes on the peoples, the languages, the geography, flora, and fauna. On 12 July 1852, Wallace embarked for England on the brig Helen. After twenty-eight days at sea, balsam in the ship's cargo caught fire and the crew was forced to abandon ship. All of the specimens Wallace had on the ship, most of his collection, were lost. He could only save part of his diary and a few sketches. Wallace and the crew spent ten days in an open boat before being picked up by the brig Jordeson.

The East Indies

From 1854 to 1862, age 31 to 39, Wallace travelled through the Dutch East Indies (now Malaysia and Indonesia), to collect specimens for sale and to study nature.  Wallace collected more than 125,000 specimens in the Dutch East Indies (more than 80,000 beetles alone).  More than a thousand of them were species new to science.

His observations of the clear zoological differences across a narrow strait in the archipelago led to his proposing the zoogeographical boundary now known as the Wallace Line. Bali and Lombok were two islands in the archipelago only 17 miles apart at the widest (28 km), roughly the same size and with the same climate, soil, elevation and aspect. Yet their flora and fauna were so different.

"In this archipelago there are two distinct faunas rigidly circumscribed, which differ as much as do those of Africa and South America... yet there is nothing on the map or on the face of the islands to mark their limits. The boundary line passes between islands closer together than others belonging to the same group. I believe the western part to be a separated portion of continental Asia, while the eastern is a fragmentary prolongation of a former west Pacific continent".

Why was it, he wondered, that the animals and plants on the Bali side of the channel were of Asian types, while those on the Lombok side were Australasian in type? This had to mean that the western group had evolved from common western stock, while the eastern group had evolved from a common eastern stock.

While he was exploring the archipelago, he thought about evolution, and had his famous insight on natural selection. In 1858 he sent an article outlining his theory to Darwin; it was published, along with a description of Darwin's own theory, in the same year.

Accounts of his studies and adventures there were eventually published in 1869 as The Malay Archipelago. It became one of the most popular natural history travel journals of the 19th century. It was praised by Charles Darwin and Charles Lyell and by others, such as the novelist Joseph Conrad, who called it his "favorite bedside companion".

Natural selection
Unlike Darwin, Wallace began his career as a travelling naturalist already believing in evolution. Both he and Bates had read Vestiges, a controversial work of popular science, published anonymously in 1844. This advocated an evolutionary origin for the Solar System, the Earth, and living things. He also read Malthus's Principle of population, which he says "twenty years later gave me the long-sought clue to the effective agent in the evolution of organic species". He meant by that the struggle for existence, which led Wallace to natural selection.

Wallace wrote his ideas on the small isle of Ternate, in what was then the Dutch East Indies. He was suffering from malaria. While the natives looked after him, his thoughts turned to Malthus's book.
"I thought of [Malthus's] clear exposition of the 'positive checks to increase' – disease, accidents, wars, famine – which keep down the population... It then occurred to me that the same causes, or their equivalents, are
continually acting in the case of animals also... Why do some die and some live? And the answer came clearly, that on the whole the best fitted live... Then it suddenly flashed upon me, that this self-acting process would necessarily improve the race..."
This was the origin of his letter to Darwin, which set out the idea of natural selection.

His views on human evolution

In 1864 Wallace published a paper, The origin of human races and the antiquity of Man deduced from the theory of natural selection, applying the theory to human beings. Huxley had already published his view that evolution applied to mankind as it did to other living things.

Wallace thought that natural selection could not account for mathematical, artistic, or musical genius, as well as metaphysical musings, wit and humour. He eventually said that something in "the unseen universe of Spirit" had interceded at least three times in history. The first was the creation of life from inorganic matter. The second was the introduction of consciousness in the higher animals. And the third was the generation of the higher mental faculties in mankind. He also believed that the purpose of the universe was the development of the human spirit.

Many, including Huxley, Hooker, and Darwin himself, were highly critical of these ideas. As one historian of science has pointed out, Wallace's views in this area were at odds with two major tenets of Darwinism. These are: evolution does not have a goal, and it is not aimed at or centered around mankind. It is thought by most biographers that his thinking on the evolution of man was influenced by his adoption of spiritualism, which happened at the same time.

Spiritualism
Wallace was not a believer in revealed religion of any kind, but he did believe in spiritualism. This has puzzled biographers, who struggle to think why such a man would believe in spirits. Early in his life, he experimented with hypnosis, which was then doubted and criticised. He used some of his students in Leicester as subjects, with considerable success. Apparently, this persuaded him not to reject ideas which were doubted. Even when Huxley told him that one of his favourite mediums was a proven fraud, he refused to believe it. He preferred the evidence of his own experience.

Wallace's public support of spiritualism, and his defence of spiritualist mediums against allegations of fraud, damaged his scientific reputation. It strained his relationships with friends such as Bates, Huxley and Darwin, who felt he was overly credulous. Others became openly hostile to Wallace over the issue. Wallace and other scientists who defended spiritualism were subject to much criticism from the press, with The Lancet, the leading English medical journal, being particularly harsh. The controversy affected the public's idea of Wallace for the rest of his career, though he was always respected in other ways.

Other interests
Wallace had a wide range of interests, and wrote books about all of them. He wrote against vaccination, for phrenology, for spiritualism, for land nationalisation, against the Moon having canals, and for social change and the progress and improvement of mankind. He did not believe in religion, but he did believe in spiritualism. He was a radical in politics, economics and social reform. He was a kind and honourable person, but he could be a tough opponent if he thought something unfair was going on. Even the titles of some of his books were sensational, as for example:

 Bad Times: an essay on the depression of trade, tracing it to its sources in enormous foreign loans, excessive war expenditure, the increase of speculation and of millionaires, and their depopulation of the rural districts; with suggested remedies. With appendix on the nationalisation of house property. Macmillan, London. 1885.
 Land nationalisation: its necessity and its aims. Being a comparison of the system of landlord and tenant with that of occupying ownership in their influence on the wellbeing of the people. Swan Sonnenschein, London 1892.
 Vaccination a delusion: its penal enforcement a crime. This essay was written for the purpose of influencing Parliament, and securing the speedy abolition of the unjust, cruel, and pernicious Vaccination laws. For this purpose, it has been necessary to speak plainly of the ignorance and incompetence displayed by the Royal Commission, proofs of which I give from their Final Report and the evidence they have collected and printed. (Preface). Reprinted as a separate from chapter XVIII of The wonderful century. Swan Sonnenschein, London 1898.

Books
Wallace wrote about 22 books, depending on how one counts them.
His greatest works include:
 1853 Travels on the Amazon and Rio Negro
 1858 On the tendency of varieties to depart indefinitely from the original type (this is the famous paper on natural selection)
 1869 The Malay Archipelago.
 1870 Contributions to the theory of natural selection.
 1876 The geographical distribution of animals
 1878 Tropical Nature, and other essays
 1880 Island Life
 1889 Darwinism

References

1823 births
1913 deaths
British naturalists
British evolutionary biologists
British explorers
Spirituality
Order of Merit
Fellows of the Royal Society
Science writers

Alfred Russel Wallace


The Democracy in Ancient Athens was very different from modern democracy. Citizens had the right to help govern but most people were not citizens.

To be classed as a citizen in fifth-century Athens you had to be male, born from two Athenian parents, over eighteen years old, and completed your military service.  Women, slaves, metics and children under the age of 20 were not allowed to become citizens.

Citizens could be involved in the running of Athens and could be chosen for important positions.  They were also allowed to own land.  Citizens were between 10% and 20% of the total population at various times in the 5th and 4th centuries.

The Ecclesia (Assembly of Men)
Ancient Athens had a direct democracy. This meant that each citizen had an equal say and opportunity in the governing of Athens. The citizens of Athens would meet on a hillside (the Pnyx) 30 to 40 times a year to discuss how to run the city better. Usually a few thousand actually came to the meeting.

All citizens could attend the meetings.  People would stand on a raised platform called the bema to speak.  Speakers wore a garland whilst speaking. Any citizen could speak.

All major decisions concerning the running of Athens were decided here – taxes, war, policy, etc. Any decisions were made by a show of hands.

A black pig would be sacrificed to the gods at the start of the meeting to make sure the meeting went well.

All democratic countries now have an indirect democracy. This means  members of parliament are elected to make decisions concerning government. There are now too many people in  countries for them to meet on a hillside, and many people are too busy to be able to go many times each year.

The Boule (Council of 500)
Cleisthenes, a democratic reformer, divided Attica into ten tribes in 510 BC. The Boule was made up of 50 male Athenian citizens chosen at random from each of the ten tribes (all over 30 years old). This meant that 500 men were elected, but only 50 served at any one time.

References

Ancient Athens
Democracy

Democracy in Athens


Baking is a skill or way of cooking food in an oven. Sometimes, though, baking can also be done in hot ashes, or hot stones. It is used for making bread, cakes, pastries, pies, tarts, cookies, and much more. Such foods made by baking are called "baked goods".

The ingredients used in baking include flour, water, leavening agents (baker's yeast, baking soda, baking powder), shortening (fats, oils), eggs, milk, and sugars. These are all mixed together to create dough or batter, which is then put into a pan or a sheet and heated. Leavening agents produce gas that becomes trapped in the dough. This makes it rise. Shortening makes doughs more easily workable and the bread that comes out in the end more soft and tender. Egg whites are used to help make a light, airy texture.

Baked goods are sold at a bakery. A person who makes baked goods as a job is called a baker. It is also used for making baked potatoes, baked apples, baked beans, some casseroles and pasta dishes such as lasagna, and various other foods, such as the pretzel.

History

In ancient history, the first baking happened when humans took wild grass grains, and soaked them in water. Then they mixed everything together, and also mashed it. After that, this mixture was poured onto a flat, hot rock, and roasted on hot embers. This new way of making bread was much easier than the other ways of doing so. This was because bread could be made anytime if there was fire.

Around 2500 BC Egyptians had bread, and may have learned how to make it from the Babylonians. Also, the Greeks around 400 B.C. tarts with patterns and honey was included in Greek food. Dispyrus, another type of baked good, was also made by the Greeks around that time. It was popular. Dispyrus was a donut-like bread made from flour and honey and shaped in a ring. Soaked in wine, it was eaten when hot. The first proof of stone ovens was in Italy, where they made pizza and pasta.

Baking was very popular in the Roman Empire. In about 300 B.C., the pastry cook became a special job for Romans (called the pastillarium). Romans loved pastry, which was often cooked for large parties. Baking became so popular during the Roman Empire that someone who could think of a new kind of pastry was given an award. Around 1 AD there were more than 300 pastry chefs in Rome.

Eventually, because of Rome, the art of baking became known in Europe. It later spread to the eastern parts of Asia, too. Bakers sometimes bake goods at home and then sell them in the streets. In London, chefs sold their baked goods from handcarts. In Paris, the first café of baked goods was made. Baking became a real art in the world. Cakes can be actually mixed in just a few minutes, with only a small bit of skill needed, and it can be lifted fresh from the oven in less than 30 minutes. A basic loaf of bread may take slightly longer time, but it does not demand a lot of time from the cook.

References

Baking


Panties are a kind of underwear. Women's panties are also called knickers. Other names are underpants ("undies"), briefs and smalls.

There are many different shapes and sizes of panties. A common type are bikini panties, which are usually small like a bikini bottom. Bloomers are panties which are loose-fitting and bigger. Panties with a high waistline are usually thought to be worn by older or more conservative women.

Panties may be made of silk, cotton, satin or man-made fabrics, and decorated with lace. Most full cut panties are made of cotton or other comfortable materials.

Names
Knickers in British English only refers to female panties; in American usage the term is also used for a type of male trousers more properly called "breeches".

Underwear
Bottoms (clothing)

Panties


Authentication (from  authentikos, "real, genuine", from αὐθέντης authentes, "author") is the act of proving an assertion, such as the identity of a computer system user. In contrast with identification, the act of indicating a person or thing's identity, authentication is the process of verifying that identity. It might involve validating personal identity documents, verifying the authenticity of a website with a digital certificate, determining the age of an artifact by carbon dating, or ensuring that a product or document is not counterfeit.

Methods

Authentication is relevant to multiple fields. In art, antiques, and anthropology, a common problem is verifying that a given artifact was produced by a certain person or in a certain place or period of history. In computer science, verifying a user's identity is often required to allow access to confidential data or systems.

Authentication can be considered to be of three types:

The first type of authentication is accepting proof of identity given by a credible person who has first-hand evidence that the identity is genuine. When authentication is required of art or physical objects, this proof could be a friend, family member, or colleague attesting to the item's provenance, perhaps by having witnessed the item in its creator's possession. With autographed sports memorabilia, this could involve someone attesting that they witnessed the object being signed. A vendor selling branded items implies authenticity, while they may not have evidence that every step in the supply chain was authenticated. Centralized authority-based trust relationships back most secure internet communication through known public certificate authorities; decentralized peer-based trust, also known as a web of trust, is used for personal services such as email or files and trust is established by known individuals signing each other's cryptographic key for instance.

The second type of authentication is comparing the attributes of the object itself to what is known about objects of that origin. For example, an art expert might look for similarities in the style of painting, check the location and form of a signature, or compare the object to an old photograph. An archaeologist, on the other hand, might use carbon dating to verify the age of an artifact, do a chemical and spectroscopic analysis of the materials used, or compare the style of construction or decoration to other artifacts of similar origin. The physics of sound and light, and comparison with a known physical environment, can be used to examine the authenticity of audio recordings, photographs, or videos. Documents can be verified as being created on ink or paper readily available at the time of the item's implied creation.

Attribute comparison may be vulnerable to forgery. In general, it relies on the facts that creating a forgery indistinguishable from a genuine artifact requires expert knowledge, that mistakes are easily made, and that the amount of effort required to do so is considerably greater than the amount of profit that can be gained from the forgery.

In art and antiques, certificates are of great importance for authenticating an object of interest and value. Certificates can, however, also be forged, and the authentication of these poses a problem. For instance, the son of Han van Meegeren, the well-known art-forger, forged the work of his father and provided a certificate for its provenance as well.

Criminal and civil penalties for fraud, forgery, and counterfeiting can reduce the incentive for falsification, depending on the risk of getting caught.

Currency and other financial instruments commonly use this second type of authentication method. Bills, coins, and cheques incorporate hard-to-duplicate physical features, such as fine printing or engraving, distinctive feel, watermarks, and holographic imagery, which are easy for trained receivers to verify.

The third type of authentication relies on documentation or other external affirmations. In criminal courts, the rules of evidence often require establishing the chain of custody of evidence presented. This can be accomplished through a written evidence log, or by testimony from the police detectives and forensics staff that handled it. Some antiques are accompanied by certificates attesting to their authenticity. Signed sports memorabilia is usually accompanied by a certificate of authenticity. These external records have their own problems of forgery and perjury and are also vulnerable to being separated from the artifact and lost.

In computer science, a user can be given access to secure systems based on user credentials that imply authenticity. A network administrator can give a user a password, or provide the user with a key card or other access devices to allow system access. In this case, authenticity is implied but not guaranteed.

Consumer goods such as pharmaceuticals, perfume, and clothing can use all  forms of authentication to prevent counterfeit goods from taking advantage of a popular brand's reputation. As mentioned above, having an item for sale in a reputable store implicitly attests to it being genuine, the first type of authentication. The second type of authentication might involve comparing the quality and craftsmanship of an item, such as an expensive handbag, to genuine articles. The third type of authentication could be the presence of a trademark on the item, which is a legally protected marking, or any other identifying feature which aids consumers in the identification of genuine brand-name goods. With software, companies have taken great steps to protect from counterfeiters, including adding holograms, security rings, security threads and color shifting ink.

Authentication factors
The ways in which someone may be authenticated fall into three categories, based on what is known as the factors of authentication: something the user knows, something the user has, and something the user is. Each authentication factor covers a range of elements used to authenticate or verify a person's identity before being granted access, approving a transaction request, signing a document or other work product, granting authority to others, and establishing a chain of authority.

Security research has determined that for a positive authentication, elements from at least two, and preferably all three, factors should be verified. The three factors (classes) and some of the elements of each factor are:

 Knowledge: Something the user knows (e.g., a password, partial password, passphrase, personal identification number (PIN), challenge–response (the user must answer a question or pattern), security question).
 Ownership: Something the user has (e.g., wrist band, ID card, security token, implanted device, cell phone with a built-in hardware token, software token, or cell phone holding a software token).
 Inherence: Something the user is or does (e.g., fingerprint, retinal pattern, DNA sequence (there are assorted definitions of what is sufficient), signature, face, voice, unique bio-electric signals, or other biometric identifiers).

Single-factor authentication
As the weakest level of authentication, only a single component from one of the three categories of factors is used to authenticate an individual's identity. The use of only one factor does not offer much protection from misuse or malicious intrusion. This type of authentication is not recommended for financial or personally relevant transactions that warrant a higher level of security.

Multi-factor authentication

Multi-factor authentication involves two or more authentication factors (something you know, something you have, or something you are). Two-factor authentication is a special case of multi-factor authentication involving exactly two factors.

For example, using a bank card (something the user has) along with a PIN (something the user knows) provides two-factor authentication. Business networks may require users to provide a password (knowledge factor) and a pseudorandom number from a security token (ownership factor). Access to a very-high-security system might require a mantrap screening of height, weight, facial, and fingerprint checks (several inherence factor elements) plus a PIN and a day code (knowledge factor elements), but this is still a two-factor authentication.

Authentication types

Strong authentication
The United States government's National Information Assurance Glossary defines strong authentication as a layered authentication approach relying on two or more authenticators to establish the identity of an originator or receiver of information.

The European Central Bank (ECB) has defined strong authentication as "a procedure based on two or more of the three authentication factors". The factors that are used must be mutually independent and at least one factor must be "non-reusable and non-replicable", except in the case of an inherence factor and must also be incapable of being stolen off the Internet. In the European, as well as in the US-American understanding, strong authentication is very similar to multi-factor authentication or 2FA, but exceeding those with more rigorous requirements.

The FIDO Alliance has been striving to establish technical specifications for strong authentication.

Continuous authentication
Conventional computer systems authenticate users only at the initial log-in session, which can be the cause of a critical security flaw. To resolve this problem, systems need continuous user authentication methods that continuously monitor and authenticate users based on some biometric trait(s). A study used behavioural biometrics based on writing styles as a continuous authentication method.

Recent research has shown the possibility of using smartphones sensors and accessories to extract some behavioral attributes such as touch dynamics, keystroke dynamics and gait recognition. These attributes are known as behavioral biometrics and could be used to verify or identify users implicitly and continuously on smartphones. The authentication systems that have been built based on these behavioral biometric traits are known as active or continuous authentication systems.

Digital authentication
The term digital authentication, also known as electronic authentication or e-authentication, refers to a group of processes where the confidence for user identities is established and presented via electronic methods to an information system. The digital authentication process creates technical challenges because of the need to authenticate individuals or entities remotely over a network.
The American National Institute of Standards and Technology (NIST) has created a generic model for digital authentication that describes the processes that are used to accomplish secure authentication:

 Enrollment – an individual applies to a credential service provider (CSP) to initiate the enrollment process. After successfully proving the applicant's identity, the CSP allows the applicant to become a subscriber.
 Authentication – After becoming a subscriber, the user receives an authenticator e.g., a token and credentials, such as a user name. He or she is then permitted to perform online transactions within an authenticated session with a relying party, where they must provide proof that he or she possesses one or more authenticators.
 Life-cycle maintenance – the CSP is charged with the task of maintaining the user's credential over the course of its lifetime, while the subscriber is responsible for maintaining his or her authenticator(s).

The authentication of information can pose special problems with electronic communication, such as vulnerability to man-in-the-middle attacks, whereby a third party taps into the communication stream, and poses as each of the two other communicating parties, in order to intercept information from each. Extra identity factors can be required to authenticate each party's identity.

Product authentication

Counterfeit products are often offered to consumers as being authentic. Counterfeit consumer goods, such as electronics, music, apparel, and counterfeit medications, have been sold as being legitimate. Efforts to control the supply chain and educate consumers help ensure that authentic products are sold and used. Even security printing on packages, labels, and nameplates, however, is subject to counterfeiting.

In their anti-counterfeiting technology guide, the EUIPO Observatory on Infringements of Intellectual Property Rights categorizes the main anti-counterfeiting technologies on the market currently into five main categories: electronic, marking, chemical and physical, mechanical, and technologies for digital media.

Products or their packaging can include a variable QR Code. A QR Code alone is easy to verify but offers a weak level of authentication as it offers no protection against counterfeits unless scan data is analyzed at the system level to detect anomalies. To increase the security level, the QR Code can be combined with a digital watermark or copy detection pattern that are robust to copy attempts and can be authenticated with a smartphone.

A secure key storage device can be used for authentication in consumer electronics, network authentication, license management, supply chain management, etc. Generally, the device to be authenticated needs some sort of wireless or wired digital connection to either a host system or a network. Nonetheless, the component being authenticated need not be electronic in nature as an authentication chip can be mechanically attached and read through a connector to the host e.g. an authenticated ink tank for use with a printer. For products and services that these secure coprocessors can be applied to, they can offer a solution that can be much more difficult to counterfeit than most other options while at the same time being more easily verified.

Packaging
Packaging and labeling can be engineered to help reduce the risks of counterfeit consumer goods or the theft and resale of products. Some package constructions are more difficult to copy and some have pilfer indicating seals. Counterfeit goods, unauthorized sales (diversion), material substitution and tampering can all be reduced with these anti-counterfeiting technologies. Packages may include authentication seals and use security printing to help indicate that the package and contents are not counterfeit; these too are subject to counterfeiting. Packages also can include anti-theft devices, such as dye-packs, RFID tags, or electronic article surveillance tags that can be activated or detected by devices at exit points and require specialized tools to deactivate. Anti-counterfeiting technologies that can be used with packaging include:

 Taggant fingerprinting – uniquely coded microscopic materials that are verified from a database
 Encrypted micro-particles – unpredictably placed markings (numbers, layers and colors) not visible to the human eye
 Holograms – graphics printed on seals, patches, foils or labels and used at the point of sale for visual verification
 Micro-printing – second-line authentication often used on currencies
 Serialized barcodes
 UV printing – marks only visible under UV light
 Track and trace systems – use codes to link products to the database tracking system
 Water indicators – become visible when contacted with water
 DNA tracking – genes embedded onto labels that can be traced
 Color-shifting ink or film – visible marks that switch colors or texture when tilted
 Tamper evident seals and tapes – destructible or graphically verifiable at point of sale
 2d barcodes – data codes that can be tracked
 RFID chips
 NFC chips

Information content
Literary forgery can involve imitating the style of a famous author. If an original manuscript, typewritten text, or recording is available, then the medium itself (or its packaging – anything from a box to e-mail headers) can help prove or disprove the authenticity of the document. However, text, audio, and video can be copied into new media, possibly leaving only the informational content itself to use in authentication. Various systems have been invented to allow authors to provide a means for readers to reliably authenticate that a given message originated from or was relayed by them. These involve authentication factors like:

 A difficult-to-reproduce physical artifact, such as a seal, signature, watermark, special stationery, or fingerprint.
 A shared secret, such as a passphrase, in the content of the message.
 An electronic signature; public-key infrastructure is often used to cryptographically guarantee that a message has been signed by the holder of a particular private key.

The opposite problem is the detection of plagiarism, where information from a different author is passed off as a person's own work. A common technique for proving plagiarism is the discovery of another copy of the same or very similar text, which has different attribution. In some cases, excessively high quality or a style mismatch may raise suspicion of plagiarism.

Literacy and literature authentication
In literacy, authentication is a readers' process of questioning the veracity of an aspect of literature and then verifying those questions via research. The fundamental question for authentication of literature is – Does one believe it? Related to that, an authentication project is therefore a reading and writing activity in which students document the relevant research process (). It builds students' critical literacy. The documentation materials for literature go beyond narrative texts and likely include informational texts, primary sources, and multimedia. The process typically involves both internet and hands-on library research. When authenticating historical fiction in particular, readers consider the extent that the major historical events, as well as the culture portrayed (e.g., the language, clothing, food, gender roles), are believable for the period.

History and state-of-the-art

Historically, fingerprints have been used as the most authoritative method of authentication, but court cases in the US and elsewhere have raised fundamental doubts about fingerprint reliability. Outside of the legal system as well, fingerprints are easily spoofable, with British Telecom's top computer security official noting that "few" fingerprint readers have not already been tricked by one spoof or another. Hybrid or two-tiered authentication methods offer a compelling the solution, such as private keys encrypted by fingerprint inside of a USB device.

In a computer data context, cryptographic methods have been developed which are not spoofable if the originator's key has not been compromised. That the originator (or anyone other than an attacker) knows (or doesn't know) about a compromise is irrelevant. However, it is not known whether these cryptographically based authentication methods are provably secure, since unanticipated mathematical developments may make them vulnerable to attack in the future. If that were to occur, it may call into question much of the authentication in the past. In particular, a digitally signed contract may be questioned when a new attack on the cryptography underlying the signature is discovered.

Authorization

The process of authorization is distinct from that of authentication. Whereas authentication is the process of verifying that "you are who you say you are", authorization is the process of verifying that "you are permitted to do what you are trying to do". While authorization often happens immediately after authentication (e.g., when logging into a computer system), this does not mean authorization presupposes authentication: an anonymous agent could be authorized to a limited action set.

Access control
One familiar use of authentication and authorization is access control. A computer system that is supposed to be used only by those authorized must attempt to detect and exclude the unauthorized. Access to it is therefore usually controlled by insisting on an authentication procedure to establish with some degree of confidence the identity of the user, granting privileges established for that identity.

See also
 Authentication protocol

References

External links

 "New NIST Publications Describe Standards for Identity Credentials and Authentication Systems"

Access control
Applications of cryptography
Computer access control
Notary
Packaging

Authentication


Antonín Leopold Dvořák (8 September 1841  1 May 1904) was a Czech composer. Along with Smetana and Janáček, Dvorak is one of three famous composers who wrote nationalist Czech music. He wrote chamber music including several string quartets, piano music, songs, operas, oratorios and nine symphonies. The last of his symphonies is known as the New World Symphony because he wrote it in the United States (the "New World"). The slow movement with its solo played on the cor anglais is especially famous.

Life

Youth
Dvořák was born in a village near Prague, Czechoslovakia (Today Prague is the capital city of the Czech Republic) but in those days it was part of the Austrian Empire until 1867 after the Austro-Prussian War Of 1866 when it became Austria-Hungary . His father was a butcher and innkeeper. He also played the zither and composed a few simple dances.

The young Antonín started to have violin lessons from the village schoolmaster. Soon he was playing the violin in his father's inn, in local churches and in the village band. Just before his 12th birthday he left school and started to learn how to be a butcher. A year later he left home to go to school in Zlonice. He learned a lot about music there, and he also learned German. His teacher persuaded Dvořák's parents that he should have a musical career, so they sent him to study music in Prague at the Organ School. He continued to learn German, and he became a good viola player and played in concerts and in the Estates Theatre when they needed a big orchestra for Wagner's operas Lohengrin and Tannhäuser.

Early career

When Dvořák had finished his studies he got his first job playing in a band in restaurants and for balls. This was a time when there was suddenly a great interest in national culture in Bohemia. Plays and operas were allowed to be performed in the Czech language. The band he played with became part of the Bohemian Provisional Theater Orchestra, which from 1866 was conducted by Bedřich Smetana. Dvořák was principal viola player in the orchestra. He earned extra money by teaching, and he started to compose.

In 1871 he left the orchestra so that he could spend more time composing. For several years he still had to teach in order to earn enough money to live. He wrote a cantata The heirs of the White Mountain which was a great success. In 1874 he wrote an opera King and Charcoal Burner, but the opera house did not want it. This made Dvořák realize that he had to be more self-critical. He destroyed a lot of his compositions which he thought were not his best works. He decided he must not compose like Wagner, but that he needed to find his own style of composing.

In 1873 he married. He got a job as church organist. His Third Symphony was performed at a concert conducted by Smetana. Dvořák rewrote his opera King and Charcoal Burner, using completely different music. It was performed in 1874. He composed a lot more music.

Years of fame

In 1877 he had a letter from Hanslick to say that he had won a prize of 600 gulden and that the great composer Johannes Brahms was interested in his music. His music started to be published by Simrock, a well-known German music publisher, and his music was performed in many countries, even as far away as New York. His fame spread. Even his operas were performed abroad. Dimitrij was particularly successful. Brahms was a great friend and helped him a lot. Brahms and Hanslick tried to persuade him to move to Vienna because it was a great musical city, but Dvořák wanted to stay in his own country.

Dvořák's Slavonic Dances were published in 1878 and have always been very popular. The conductor Hans Richter conducted the Slavonic Rhapsody no 3 in Vienna. His Stabat Mater (1880) was performed abroad, and Dvořák was invited to visit England in 1884. He became very popular in England and went there many times. The English choirs liked to sing his choral works. His Requiem Mass was given its first performance in Birmingham at the Triennial Music Festival. He was given an honorary degree from Cambridge University. Tchaikovsky invited him to Russia in 1890.

America (1892–1895)
From 1892 to 1895, Dvořák was the director of the National Conservatory of Music in New York City. He earned a lot of money: $15,000 a year. Dvořák was interested in the music of black Americans. He met the student Harry T. Burleigh, one of the earliest African-American composers, who introduced him to traditional American Spirituals.

In the winter and spring of 1893, while in New York, Dvořák wrote his most popular work, the Symphony No.9, "From the New World". He spent the summer of 1893 with his family in the Czech-speaking community of Spillville, Iowa, where some of his cousins lived. He also composed chamber music there, including a String Quartet in F which is known as the "American", and a Sonatina for Violin and Piano.

In 1895, Dvořák wrote his Cello Concerto in B minor, which was to become one of his most popular works. However, he wanted to go back to his own country. He was also not being paid all his salary. He heard that he had been made an honorary member of the Gesellschaft der Musikfreunde in Vienna. He decided to return to Bohemia and continue his job as professor of composition at the Prague Conservatory.

Last years
During his last years, Dvořák spent most of his time writing operas. Rusalka is particularly popular, especially the famous aria for soprano To the Moon. The opera is about a fairy-tale and the story is based on Hans Anderson's story of the Little Mermaid. In 1896 he visited London for the last time to hear the first performance of his Cello Concerto. In 1897 his daughter married his pupil, the composer Josef Suk.

He died in 1904 after a short illness.

His music

Dvořák wrote lots of kinds of music. Although he based his style on the classical forms such as those of Beethoven, they also show the influence of Czech folksong. He lived at a time when Nationalistic feelings were felt very strongly by the Czech people. Smetana wrote music which was very Czech in character. Dvořák learned from Smetana's music, but never imitated his style. Only five of his nine symphonies were known in his lifetime. When the other four were discovered and published in the 1960s the symphonies were all renumbered. The last three symphonies, numbers 7, 8 and 9 (which used to be called numbers 2, 4 and 5) are the most often performed. The Ninth Symphony: From the New World is one of the most popular symphonies ever written. The two sets of Slavonic Dances are extremely well-known. They are often played as a piano duet. He wrote concertos for the violin, cello and piano. Dvořák wrote many operas (the best known of which is Rusalka); chamber music (including a number of string quartets, and quintets); songs; choral music; and piano music.

Books about Dvořák
Slavonic rhapsody: The life of Antonín Dvořák, by Barthold Fles

References

Czech composers
Romantic composers
1841 births
1904 deaths

Antonín Dvořák


An elevator or lift is a vertical transport vehicle that efficiently moves people or goods between floors of a building, ship or other structure. They are generally powered by electric motors that either drive traction cables and counterweight systems, or pump hydraulic fluid to raise a cylindrical piston.
Languages other than English may have loanwords based on either elevator (e.g., Japanese) or lift (e.g., Cantonese).
Because of wheelchair access laws, elevators are often a legal requirement in new multi-story buildings, especially where wheelchair ramps would be impractical.

Design

Some argue that lifts began as simple rope or chain hoists. A lift is essentially a platform that is either pulled or pushed up by a mechanical means. A modern-day lift consists of a cab (also called a "cage" or "car") mounted on a platform within an enclosed space called a shaft or sometimes a "hoistway". In the past, lift drive mechanisms were powered by steam and water hydraulic pistons. In a "traction" lift, cars are pulled up by means of rolling steel ropes over a deeply grooved pulley, commonly called a sheave in the industry. The weight of the car is balanced with a counterweight. Sometimes two lifts always move synchronously in opposite directions, and they are each other's counterweight

The friction between the ropes and the pulley furnishes the traction which gives this type of lift its name.

Hydraulic lifts use the principles of hydraulics (in the sense of hydraulic power) to pressurize an above ground or in-ground piston to raise and lower the car. Roped hydraulics use a combination of both ropes and hydraulic power to raise and lower cars. Recent innovations include permanent earth magnet motors, machine room-less rail mounted gearless machines, and microprocessor controls.

The technology used in new installations depends on a variety of factors. Hydraulic lifts are cheaper, but installing cylinders greater than a certain length becomes impractical for very high lift hoistways. For buildings of much over seven stories, traction lifts must be employed instead. Hydraulic lifts are usually slower than traction lifts.

Lifts are a candidate for mass customization.
There are economies to be made from mass production of the components, but each building comes with its own requirements like different number of floors, dimensions of the well and usage patterns.

Elevator doors
Elevator doors protect riders from being crushed in between the cab and the floor. The most common configuration is to have two panels that meet in the middle, and slide open laterally. In a cascading configuration (potentially allowing wider entryways within limited space), the doors run on independent tracks so that while open, they are tucked behind one another, and while closed, they form cascading layers on one side. This can configured so that two sets of such cascading doors operate like the center opening doors described above, allowing for a very wide elevator cab. In less expensive installations the elevator can also use one large "slab" door: a single panel door the width of the doorway that opens to the left or right laterally.

Machine Room-Less (MRL)
General

All elevators, whether traction or hydraulic, require a machine room to store large electric motors (or hydraulic pumps) and a controller cabinet. This room is located above or below the hoistway (or only below, for hydraulic elevators) and may contain machinery for a single or a group of elevators. Modern day traction motors boasting gearless and permanent magnet drive can be more compact and efficient; electronic microprocessors have replaced the mechanical relays. As a result, traction elevators can be built without a dedicated room above the shaft, saving valuable space in building planning.

The new lift design presents a departure from the traditional, looped over-the-top traction rope routing of traction elevators. The ends of the cables are fixed to the supporting structure, and the length of the cable are connected to the car and counterweight by means of a force-multiplying, energy saving compound pulley system. Machine room-less elevators have become a welcome alternative to the older hydraulic elevator for low to medium rise buildings.

Kone, a Finnish elevator company, first developed the machine room-less elevator in 1996.

Benefits from a Green Perspective
 creates more usable space
 uses less energy (70-80% less than hydraulic elevators)
 uses no oil
 all components are above ground
---this takes away the environmental concern that was created by the hydraulic cylinder being stored underground

Other Benefits
 much lower cost than other elevators
 ride quality is better due to gearless traction
 operates at faster speeds than hydraulics

Facts
 Noise level is at 50-55 dBA (A-weighted decibels), which is much lower than other types of elevators
 Usually used for low-rise to mid-rise buildings
 The motor mechanism is placed in the hoistway itself
 The US was slow to accept the MRL Elevator because of codes
---national and local building codes did not address elevators without machine rooms

History
The first reference to an elevator is in the works of the Roman architect Vitruvius, who reported that Archimedes built his first elevator, probably in 236 B.C. In some literary sources of later historical periods, elevators were mentioned as cabs on a hemp rope and powered by hand or by animals. It is supposed that elevators of this type were installed in the Sinai monastery of Egypt. In the 17th century the prototypes of elevators were located in the palace buildings of England and France.

In 1852, Elisha Otis introduced the safety elevator, which prevented the fall of the cab if the cable broke. The design of the Otis safety elevator is somewhat similar to one type still used today. A governor device engages knurled roller(s), locking the elevator to its guides should the elevator move at an excessive speed. He demonstrated it at the New York exposition in the Crystal Palace in 1854.

In 1874, J.W. Meaker patented a method which permitted elevator doors to open and close safely.

The first electric elevator was constructed by the German engineer Werner von Siemens in 1880.

In 1882, when hydraulic power was a well established technology, a company later named the London Hydraulic Power Company was formed. It constructed a network of high pressure mains on both sides of the Thames which, ultimately, extended to 184 miles and powered some 8,000 machines, predominantly lifts (elevators) and cranes.

In 1929, Clarence Conrad Crispen, with Inclinator Company of America, created the first residential elevator. Crispen also invented the first inclined stairlift.http://inclinator.com/about-inclinator.asp

Elevator safety

Pneumatic Vacuum Elevators
Pneumatic or "Vacuum" elevators operate without cables and can be installed more easily and quickly than their alternatives since their housing comprises prefabricated sections which are considerably narrower than conventional lift shafts. These sections are often transparent and afford the passenger a near 360° view.

Cable-borne elevators
Statistically speaking, elevators are extremely safe. Their safety record is unsurpassed by any other vehicle system. In 1998, it was estimated that approximately eight 100-millionths of one percent (1 in 12 million) of elevator rides resulted in an anomaly, and the vast majority of these were minor things such as the doors failing to open. For all practical purposes, there are no cases of elevators simply free-falling and killing the passengers inside; of the 20 to 30 elevator-related deaths each year, most of them are maintenance-related - for example, technicians leaning too far into the shaft or getting caught between moving parts, and most of the rest are attributed to easily avoidable accidents, such as people stepping blindly through doors that open into empty shafts or being strangled by scarves caught in the doors. In fact, prior to the September 11th terrorist attacks, the only known free-fall incident in a modern cable-borne elevator happened in 1945 when a B-25 bomber struck the Empire State Building in fog, severing the cables of an elevator cab, which fell from the 75th floor all the way to the bottom of the building, seriously injuring (though not killing) the sole occupant - the female elevator operator. While it is possible (though extraordinarily unlikely) for an elevator's cable to snap, all elevators in the modern era have been fitted with several safety devices which prevent the elevator from simply free-falling and crashing. An elevator cab is typically borne by six or eight hoist cables, each of which is capable on its own of supporting the full load of the elevator plus twenty-five per cent more weight. In addition, there is a device which detects whether the elevator is moving faster than its maximum designed speed; if this happens, the device causes bronze brake shoes to clamp down along the vertical rails in the shaft, stopping the elevator quickly, but not so abruptly as to cause injury. In addition, a hydraulic buffer is installed at the bottom of the shaft to cushion any impact somewhat.

Most recently, there was an incident in a modern cable-borne elevator that took place in a children's hospital in Seattle, Washington on October 9, 2007. The elevator involved was a ThyssenKrupp ISIS machine room-less elevator; The ISIS used Kevlar fiberglass ropes instead of conventional braided-steel ropes all other traction elevators use. One of the ISIS elevators broke free from its cables, slipping between the 6th and 4th floors; the Kevlar ropes were the cause of this incident. After the incident, ThyssenKrupp discontinued production of the ISIS and, the following year, replaced it with the Synergy machine room-less elevator, which uses conventional braided-steel ropes, making it much safer.

Hydraulic elevators
Past problems with early hydraulic elevators meant those built prior to a code change in 1972 were subject to possible catastrophic failure. The code had previously required only single-bottom hydraulic cylinders. In the event of a cylinder breach, an uncontrolled fall of the elevator might result. Because it is impossible to verify the system completely without a pressurized casing (as described below), it is necessary to remove the piston to inspect it. The cost of removing the piston is such that it makes no economic sense to re-install the old cylinder; therefore it is necessary to replace the cylinder and install a new piston. Another solution to protect against a cylinder blowout is to install a "life jacket." This is a device which, in the event of an excessive downward speed, clamps onto the cylinder and stops the car. This device is also known as a Rupture Valve in some parts of the world.

In addition to the safety concerns for older hydraulic elevators, there is risk of leaking hydraulic oil into the aquifer and causing potential environmental contamination. This has led to the introduction of PVC liners (casings) around hydraulic cylinders which can be monitored for integrity.

In the past decade, recent innovations in inverted hydraulic jacks have eliminated the costly process of drilling the ground to install a borehole jack. This also eliminates the threat of corrosion to the system and increases safety.

Types of hoist mechanisms
There are at least four means of moving an elevator:

Traction elevators
 Geared and gearless traction elevators
Geared traction machines are driven by AC or DC electric motors. Geared machines use worm gears to control mechanical movement of elevator cars by "rolling" steel hoist ropes over a drive sheave which is attached to a gearbox driven by a high speed motor. These machines are generally the best option for basement or overhead traction use for speeds up to 500 ft/min (2.5 m/s).

Gearless traction machines are low speed (low RPM), high torque electric motors powered either by AC or DC. In this case, the drive sheave is directly attached to the end of the motor. Gearless traction elevators can reach speeds of up to 2,000 ft/min (10 m/s), or even higher. A brake is mounted between the motor and drive sheave (or gearbox) to hold the elevator stationary at a floor. This brake is usually an external drum type and is actuated by spring force and held open electrically; a power failure will cause the brake to engage and prevent the elevator from falling (see inherent safety and safety engineering).

In each case, cables are attached to a hitch plate on top of the cab or may be "underslung" below a cab, and then looped over the drive sheave to a counterweight attached to the opposite end of the cables which reduces the amount of power needed to move the cab. The counterweight is located in the hoist-way and rides a separate rail system; as the car goes up, the counterweight goes down, and vice versa. This action is powered by the traction machine which is directed by the controller, typically a relay logic or computerized device that directs starting, acceleration, deceleration and stopping of the elevator cab. The weight of the counterweight is typically equal to the weight of the elevator cab plus 40-50% of the capacity of the elevator. The grooves in the drive sheave are specially designed to prevent the cables from slipping. "Traction" is provided to the ropes by the grip of the grooves in the sheave, thereby the name. As the ropes age and the traction grooves wear, some traction is lost and the ropes must be replaced and the sheave repaired or replaced.

Elevators with more than 100' (30 m) of travel have a system called compensation. This is a separate set of cables or a chain attached to the bottom of the counterweight and the bottom of the elevator cab. This makes it easier to control the elevator, as it compensates for the differing weight of cable between the hoist and the cab. If the elevator cab is at the top of the hoist-way, there is a short length of hoist cable above the car and a long length of compensating cable below the car and vice versa for the counterweight. If the compensation system uses cables, there will be an additional sheave in the pit below the elevator, to guide the cables. If the compensation system uses chains, the chain is guided by a bar mounted between the counterweight rails.

Hydraulic elevators
 Conventional hydraulic elevators. They use an underground cylinder, are quite common for low level buildings with 2-7 floors, and have speeds of up to 200 feet/minute (1 meter/second).
 Holeless hydraulic elevators were developed in the 1970s, and use a pair of above ground cylinders, which makes it practical for environmentally or cost sensitive buildings with 2, 3, or 4 floors.
 Roped hydraulic elevators use both above ground cylinders and a rope system, which combines the versatility of inground hydraulic with the reliability of holeless hydraulic, even though they can serve up to 8-10 floors.

Climbing elevator
A climbing elevator is a self-ascending elevator with its own propulsion. The propulsion can be done by an electric or a combustion engine. Climbing elevators are used in guyed masts or towers, in order to make easy access to parts of these constructions, such as flight safety lamps for maintenance. An example would be the Moonlight Towers in Austin, Texas, where the elevator holds only one person and equipment for maintenance.

Emergency power operation (EPR)
Many elevator installations now feature emergency power systems which allow elevator use in blackout situations and prevent people from becoming trapped in elevators.

Traction elevators
When power is lost in a traction elevator system, all elevators will initially come to a halt. One by one, each car in the group will return to the lobby floor, open its doors and shut down. People in the remaining elevators may see an indicator light or hear a voice announcement informing them that the elevator will return to the lobby shortly. Once all cars have successfully returned, the system will then automatically select one or more cars to be used for normal operations and these cars will return to service. The car(s) selected to run under emergency power can be manually overridden by a key or strip switch in the lobby. In order to help prevent entrapment, when the system detects that it is running low on power, it will bring the running cars to the lobby or nearest floor, open the doors and shut down.

Hydraulic elevators
In hydraulic elevator systems, emergency power will lower the elevators to the lowest landing and open the doors to allow passengers to exit. The doors then close after an adjustable time period and the car remains unusable until reset, usually by cycling the elevator main power switch. Typically, due to the high current draw when starting the pump motor, hydraulic elevators are not run using standard emergency power systems. Buildings like hospitals and nursing homes usually size their emergency generators to accommodate this draw. However, the increasing use of current limiting motor starters, commonly known as "Soft-Start" contactors, avoid much of this problem and the current draw of the pump motor is less of a limiting concern.

Elevator convenience features

Elevators may feature talking devices as an accessibility aid for the blind. In addition to floor arrival notifications, the computer announces the direction of travel, and notifies the passengers before the doors are to close.

In addition to the call buttons, elevators usually have floor indicators (often illuminated by LED) and direction lanterns. The former are almost universal in cab interiors with more than two stops and may be found outside the elevators as well on one or more of the floors. Floor indicators can consist of a dial with a rotating needle, but the most common types are those with successively illuminated floor indications or LCDs. Likewise, a change of floors or an arrival at a floor is indicated by a sound, depending on the elevator.

Direction lanterns are also found both inside and outside elevator cars, but they should always be visible from outside because their primary purpose is to help people decide whether or not to get on the elevator. If somebody waiting for the elevator wants to go up, but a car comes first that indicates that it is going down, then the person may decide not to get on the elevator. If the person waits, then one will still stop going up. Direction indicators are sometimes etched with arrows or shaped like arrows and/or use the convention that one that lights up red means "down" and green means "up". Since the color convention is often undermined or overrided by systems that do not invoke it, it is usually used only in conjunction with other differentiating factors. An example of a place whose elevators use only the color convention to differentiate between directions is the Museum of Contemporary Art in Chicago, where a single circle can be made to light up green for "up" and red for "down." Sometimes directions must be inferred by the position of the indicators relative to one another.

In addition to lanterns, most elevators have a chime to indicate if the elevator is going up or down either before or after the doors open, usually in conjunction with the lanterns lighting up. Universally, one chime is for up, two is for down, and none indicates an elevator that is 'free'.

Observatory service elevators often convey other facts of interest, including elevator speed, stopwatch, and current position (altitude), as with the case for Taipei 101's service elevators.

Standards
The mechanical and electrical design of elevators is dictated according to various standards (aka elevator codes), which may be international, national, state, regional or city based. Whereas once many standards were prescriptive, specifying exact criteria which must be complied with, there has recently been a shift towards more performance-based standards where the onus falls on the designer to ensure that the elevator meets or exceeds the standard..

Some of the national elevator standards include:
 Australia – AS1735
 Canada – CAN/CSA B44
 Europe – EN 81 series (EN 81-1, EN 81-2, EN 81-28, EN 81-70, EN 12015, EN 12016, EN 13015, etc.)
 USA – ASME A17

Because an elevator is part of a building, it must also comply with standards relating to earthquake resilience, fire standards, electrical wiring rules and so forth.

The American National Elevator Standards Group (ANESG) sets an elevator weight standard to be 2200 lbs.

Additional requirements relating to access by disabled persons, may be mandated by laws or regulations such as the Americans with Disabilities Act.

References

Construction

Elevator


Guangxi is a provincial-level autonomous region of the People's Republic of China where mostly Zhuang people live.

Guangxi's capital in Nanning. Other major cities are Baise, Beihai, Chongzuo, Fangchenggang, Guigang, Guilin, Hechi, Hezhou, Laibin, Liuzhou, Qinzhou, Wuzhou and Yulin.

It is near Vietnam and has many mountains. It is one of the border frontiers of Chinese civilization. Even in the 20th century it was considered an open, wild territory. The current name "Guang" itself means "expanse", and has been associated with the region since the creation of Guang Prefecture in 226 AD. It was given provincial level status during the Yuan Dynasty and in 1949 was reformed as one of China's five autonomous regions.

Guangxi


A disease or medical condition is an unhealthy state where something bad happens to the body or mind.  Diseases can cause pain, parts of the body to stop working the right way, or death. The word disease is sometimes used to include:
 parts of the body being hurt,
 not having the usual abilities,
 medical problems or syndromes,
 infections by microorganisms,
 feeling unhealthy, such as having pain or feeling hot (called 'symptoms'),
 unusual shapes of body parts.

Causes
A disease can be caused by many things.  Sometimes germs enter our body through food, water or air.  A person can be infected by infectious agents like bacteria, viruses or fungus. Disease can also be caused by eating bad or old foods. There are small germs in old foods that can cause diseases. Sometimes the germs produce chemicals or toxins which causes the disease.

One of the most common causes of disease is poor sanitation and lack of clean water.  Some deadly diseases like malaria in tropical parts of the world are spread by a mosquito.  Animals that spread disease are called vectors. There are many vectors, including snails, ticks, and fleas.

Some people are born with 'genetic diseases'. These are diseases because of an error or mutation in a person's DNA. An example of a mutation is cancer. Living or working in an unhealthy environment can also be a cause for diseases. Diseases are more common in older people.

Treatments
Some diseases can be helped with medicine. Infections can often be cured by antibiotics, though resistance to antibiotics is a problem. Some disease may be helped by surgery. Not every disease can be helped with medicine or surgery, though. Some diseases must be treated during the whole life; they are chronic (long-lasting) diseases. An example of a chronic disease is diabetes mellitus. Diabetes can be treated (made better) but it can not yet be cured (made to totally go away). People who usually treat diseases are called doctors or physicians.

Prevention
Some diseases that are common or very bad are tested for even in people who do not show any symptoms. If these diseases are found early they can be treated before they cause problems. An example would be checking a woman for cervical cancer with a test called a pap smear. If cervical cancer is found early it can be cured. If it is found later it usually causes death.

Another example is immunization. The basic idea is to make the body ready for a disease. The body has its own defense against disease called the immune system. One special characteristic of the immune system is its ability to remember some diseases. If a person is sick and recovers, the immune system will produce a substance called antibodies which fight the disease if it comes back to the person.

The antibody is specific to a particular disease or antigen. An example of this is measles which is a virus. A person (usually a child) who had never been sick with measles is given a milder form of the virus, this causes the immune system to produce antibodies against the virus. If this person is exposed to the same virus in the future, the person's immune system will remember and will fight the virus.

For general prevention to be useful:
The disease must be found and stopped in early stage.
The disease should be common or be easy to recognize.
The test for the disease should be easy, work all the time, and not hurt people.
The society is well-trained and can recognize most common symptoms on some diseases.
The treatment for the disease should be safe and be easy for people to get.

Epidemiology

Epidemiology is the study of the cause of disease. Some diseases are more popular for people with common characteristics, like similar origins, sociological background, food or nationality. Without good epidemiological research some diseases can be hard to track and to name. Some diseases can be taken for something else. This is why epidemiology takes a huge part in understanding how to protect ourselves against viruses, toxins and bacteria.

Related pages
Health
Healthy lifestyle
Viruses

References

Basic English 850 words

Disease


Carl Linnaeus (23 May 1707 – 10 January 1778), also known as Carolus Linnaeus, was a Swedish botanist, physician and zoologist who created the binomial nomenclature. In this system, every kind of animal and plant is given a name consisting of two Latin words, for its genus and species. This became used by biologists all over the world, so he is known as the "father of modern taxonomy". He was a good linguist, and famous in his time. He was made a noble by the Swedish king.

Biography

Early life
Carl was born in Sweden. He was going to be a priest like his father, but did not do well enough in school for that. Instead, Carl studied at a college for botany because he liked it. He studied in Lund and tried to improve the garden there. He later went to another college.

Travels and research
In 1735, Linnaeus moved to the Netherlands for three years. There, he earned his degree in medicine. He also published his book on plant classification. His book was called Systema Naturæ. His book explained how to classify living things by putting them into groups. Some of these groups are bigger than others.

Later he moved to Stockholm and practiced as a doctor. In 1739, Linnaeus married Sara Morea in Stockholm. Throughout the 1740s he conducted many field trips to places in Sweden to name plants and animals. When not on travels, Linnaeus worked on his classification, so it would work for plants, animals, and minerals.

The Swedish king Adolf Fredrik made Linnaeus a noble in 1757, and Linnaeus took the last name von Linné, later often signing just Carl Linné.

Last years
After he was made a noble, he continued teaching and writing. His reputation had spread over the world, and he talked with many different people. Linnaeus was upset by weak health, and he had gout and tooth aches. A stroke in 1774 weakened him, and two years later he had another, losing the use of his right side. He died in January 1778 and was buried in Uppsala cathedral.

Mankind

Linnaeus classified man as among the primates, which was claimed by anthropologists like Blumenbach and natural historians like Buffon. It attracted the criticism of the Swedish church. The Lutheran Archbishop of Uppsala accused him of "impiety".

Linnaeus recognised four races in the human species. These were European whites, American reds (Native Americans), Asian browns, and African blacks. Blumenbach's classification was similar, with the addition of a Mongolian (= Chinese) or yellow race. Thus recognition of man's position as a primate and the existence of races was quite widespread before the theory of evolution was formulated.

Related pages
 List of biologists

Notes and references

Sources
 Sörlin & Fagerstedt, Linné och hans lärjungar, 2004.
 J.L.P.M.Krol, Linneaus' verblijf op de Hartekamp In: Het landgoed de Hartekamp in Heemstede. Heemstede, 1982.

1707 births
1778 deaths
Taxonomy
Swedish physicians
Naturalists
Swedish biologists
Botanists
Deaths from stroke

Carl Linnaeus


The Odyssey is a major Ancient Greek epic poem. It was written by Homer, as a sequel to the Iliad. In its origin it was an oral epic poem from Mycenaean Greece, about the 11th century BC. The hero of the poem is Odysseus, or Ulysses as he is called in Latin; the poem is mythological, not historical.

The poem is the story about Odysseus's ten-year-long voyage home to Ithaca after the Trojan War. The Trojan War is the subject of the Iliad. At the same time, his wife Penelope has to fight off a lot of men who want to marry her; and his son Telemachos searches for him.

Along the way, Odysseus and his men have to fight monsters and many other dangers. The main events (places he goes, creatures and people he meets) of Odysseus' journey are:
 the Kikones
 the Lotus Eaters
 the Cyclops Polyphemus
 Aeolus, King of the winds
 the Laistrygones
 the sorceress Circe
 the Underworld
 the Sirens
 the sea monsters Scylla and Charybdis
 Helios' cattle
 the nymph Calypso
 the Phaeacians

Story
It is the story of the return of Ulysses after the Trojan War (Iliad)

The Cyclops

On his journey home, Odysseus lands on the island of the Cyclops Polyphemus.  They go inside his cave at the sight of sheep, cheese and milk.  Polyphemus catches them and eats some of Odysseus' men.  Odysseus tricks and blinds him and they escape.  The Cyclops prays to his father Poseidon that Odysseus would not get home to Ithaca and if he was fated to make it home, Odysseus would lose all of his men, his ship and find trouble at home.  This prayer becomes the plot line of the Odyssey.

The Sirens

Odysseus and his ship have to pass the Sirens' island. The Sirens were always singing very beautifully, so sailors would try to go to them, but their ships would get destroyed, and they would die.
Odysseus tells his men to put wax in their ears, so they will not hear the song of the sirens. He also tells his men to bind him to the ship's mast, so he cannot go to the sirens when he hears their song. His men can then look at Odysseus and see when he cannot hear the sirens anymore, because he is calm again. Then they can take the wax out of their ears, and free Odysseus.

Calypso

After escaping from the sea, and the death of his men, Odysseus comes to the island Ogygia. On this island lives the nymph Calypso, and Odysseus stayed with her for seven years. But then the god Hermes came and told her that the gods said that she had to let Odysseus go. Calypso promised Odysseus immortality (that he would live forever) if he stayed, but he wanted to go back to his wife Penelope. So Odysseus built a raft and left her.

The Phaeacians
After a storm, Odysseus comes to the island of the Phaeacians. There he is found by the king's daughter Nausicaä. Nausicaä brings him to the palace of her father, King Alkinoos. During his time there, Odysseus tell the story of his journey. After this, Alkinoos gives Odysseus a ship and sends him home to Ithaca.

Return home
During all this time, Penelope has been keeping the suitors at bay with a ruse (trick). She promises "I will choose when I have finished weaving this cloth", the cloth being a burial cloth for Odysseus' father. However, every night her servant unpicks the work of the previous day. The story is made more real by Penelope becoming restless. The goddess Athena causes Penelope to feel the need to display herself, and fan the flames of the suitors' desire.

Odysseus finally returns to Ithaca, where he disguises himself as a beggar. He goes to his home and meets his son Telemachus. Together they kill the suitors, who are trying to marry Penelope in order to gain his kingdom. Later, the families of the suitors come to kill Odysseus for revenge. The goddess Athena helps Odysseus by making them stop and give up the fight.

Notes
 The English word odyssey, meaning long journey, comes from this poem.
 The Roman name for Odysseus is Ulysses.
 James Joyce's 1922 book Ulysses is based on the book by Homer, but it is very different.

References

Other websites

 Odyssey -Citizendium

Greek mythology
Classical Greek literature
Epic poems
8th-century BC books

Odyssey


The Royal Opera House is a famous opera house  in London. Sometimes it is called  "Covent Garden" because it is in the area of London called Covent Garden.  The Royal Opera House is the home of the Royal Opera and the Royal Ballet.  There is an orchestra which plays there for all the operas and ballets.

The building that is now the Royal Opera House is the third building in that place.  The first theatre to be built there in 1732 was burnt down in 1808.  The second theatre opened in 1809 but was burnt down in 1856.  Today's building was built in 1858, although a lot of it was rebuilt between 1996 and 2000.  The auditorium (the main part where the audience sits) is nearly the same, but all the backstage rooms are new: the dressing rooms, rehearsal rooms, office space etc.  There is an extra small theatre called the Linbury Theatre which is used for smaller performances.  Together with the new restaurant areas it has helped to get more young people to come.

The Royal Opera House seats 2,268 people.  There are seats downstairs (the stalls), four tiers of boxes, a balcony and a gallery.

The conductor ("Musical Director") of the Royal Opera House Orchestra is Antonio Pappano who is a young British conductor.

Other websites
 Royal Opera House
Opera houses
Buildings and structures in the City of Westminster

Royal Opera House