Signs and symptoms.

Trichotillomania is usually confined to one or two sites, but can involve multiple sites. The scalp is the most common pulling site, followed by the eyebrows, eyelashes, face, arms, and legs. Some less common areas include the pubic area, underarms, beard, and chest. The classic presentation is the "Friar Tuck" form of vertex and crown alopecia. Children are less likely to pull from areas other than the scalp.  People who suffer from trichotillomania often pull only one hair at a time and these hair-pulling episodes can last for hours at a time. Trichotillomania can go into remission-like states where the individual may not experience the urge to "pull" for days, weeks, months, and even years.  Individuals with trichotillomania exhibit hair of differing lengths; some are broken hairs with blunt ends, some new growth with tapered ends, some broken mid-shaft, or some uneven stubble. Scaling on the scalp is not present, overall hair density is normal, and a hair pull test is negative (the hair does not pull out easily). Hair is often pulled out leaving an unusual shape. Individuals with trichotillomania may be secretive or shameful of the hair pulling behavior.  An additional psychological effect can be low self-esteem, often associated with being shunned by peers and the fear of socializing, due to appearance and negative attention they may receive. Some people with trichotillomania wear hats, wigs, false eyelashes, eyebrow pencil, or style their hair in an effort to avoid such attention. There seems to be a strong stress-related component. In low-stress environments, some exhibit no symptoms (known as "pulling") whatsoever. This "pulling" often resumes upon leaving this environment. Some individuals with trichotillomania may feel they are the only person with this problem due to low rates of reporting.  For some people, trichotillomania is a mild problem, merely a frustration. But for many, shame and embarrassment about hair pulling causes painful isolation and results in a great deal of emotional distress, placing them at risk for a co-occurring psychiatric disorder, such as a mood or anxiety disorder. Hair pulling can lead to great tension and strained relationships with family members and friends. Family members may need professional help in coping with this problem.  Other medical complications include infection, permanent loss of hair, repetitive stress injury, carpal tunnel syndrome, and gastrointestinal obstruction as a result of trichophagia. In trichophagia, people with trichotillomania also ingest the hair that they pull; in extreme (and rare) cases this can lead to a hair ball (trichobezoar). Rapunzel syndrome, an extreme form of trichobezoar in which the "tail" of the hair ball extends into the intestines, can be fatal if misdiagnosed.  Environment is a large factor which affects hair pulling. Sedentary activities such as being in a relaxed environment are conducive to hair pulling. A common example of a sedentary activity promoting hair pulling is lying in a bed while trying to rest or fall asleep. An extreme example of automatic trichotillomania is found when some patients have been observed to pull their hair out while asleep. This is called sleep-isolated trichotillomania.

Causes.

Anxiety, depression and obsessive–compulsive disorder are more frequently encountered in people with trichotillomania. Trichotillomania has a high overlap with post traumatic stress disorder, and some cases of trichotillomania may be triggered by stress. Another school of thought emphasizes hair pulling as addictive or negatively reinforcing, as it is associated with rising tension beforehand and relief afterward. A neurocognitive model — the notion that the basal ganglia plays a role in habit formation and that the frontal lobes are critical for normally suppressing or inhibiting such habits — sees trichotillomania as a habit disorder.  Abnormalities in the caudate nucleus are noted in OCD, but there is no evidence to support that these abnormalities can also be linked to trichotillomania. One study has shown that individuals with trichotillomania have decreased cerebellar volume. These findings suggest some differences between OCD and trichotillomania. There is a lack of structural MRI studies on trichotillomania. In several MRI studies that have been conducted, it has been found that people with trichotillomania have more gray matter in their brains than those who do not suffer from the disorder.  It is likely that multiple genes confer vulnerability to trichotillomania. One study identified mutations in the SLITRK1 gene.

Diagnosis.

Patients may be ashamed or actively attempt to disguise their symptoms. This can make diagnosis difficult as symptoms are not always immediately obvious, or have been deliberately hidden to avoid disclosure. If the patient admits to hair pulling, diagnosis is not difficult; if patients deny hair pulling, a differential diagnosis must be pursued. The differential diagnosis will include evaluation for alopecia areata, iron deficiency, hypothyroidism, tinea capitis, traction alopecia, alopecia mucinosa, thallium poisoning, and loose anagen syndrome. In trichotillomania, a hair pull test is negative.  A biopsy can be performed and may be helpful; it reveals traumatized hair follicles with perifollicular hemorrhage, fragmented hair in the dermis, empty follicles, and deformed hair shafts. Multiple catagen hairs are typically seen. An alternative technique to biopsy, particularly for children, is to shave a part of the involved area and observe for regrowth of normal hairs.

Classification.

Trichotillomania is defined as a self-induced and recurrent loss of hair. It includes the criterion of an increasing sense of tension before pulling the hair and gratification or relief when pulling the hair. However, some people with trichotillomania do not endorse the inclusion of "rising tension and subsequent pleasure, gratification, or relief" as part of the criteria because many individuals with trichotillomania may not realize they are pulling their hair, and patients presenting for diagnosis may deny the criteria for tension prior to hair pulling or a sense of gratification after hair is pulled.  Trichotillomania may lie on the obsessive-compulsive spectrum, also encompassing obsessive-compulsive disorder (OCD), body dysmorphic disorder (BDD), nail biting (onychophagia) and skin picking (dermatillomania), tic disorders and eating disorders. These conditions may share clinical features, genetic contributions, and possibly treatment response; however, differences between trichotillomania and OCD are present in symptoms, neural function and cognitive profile. In the sense that it is associated with irresistible urges to perform unwanted repetitive behavior, trichotillomania is akin to some of these conditions, and rates of trichotillomania among relatives of OCD patients is higher than expected by chance. However, differences between the disorder and OCD have been noted, including: differing peak ages at onset, rates of comorbidity, gender differences, and neural dysfunction and cognitive profile. When it occurs in early childhood, it can be regarded as a distinct clinical entity.  Because trichotillomania can be present in multiple age groups, it is helpful in terms of prognosis and treatment to approach three distinct subgroups by age: preschool age children, preadolescents to young adults, and adults.  In preschool age children, trichotillomania is considered benign. For these children, hair-pulling is considered either a means of exploration or something done subconsciously, similar to nail-biting and thumb-sucking, and almost never continues into further ages.  The most common age of onset of trichotillomania is between ages 9 and 13. In this age range, trichotillomania is usually chronic, and continues into adulthood. Trichiotillomania that begins in adulthood most commonly arises from underlying psychiatric causes.  Trichotillomania is often not a focused act, but rather hair pulling occurs in a "trance-like" state; hence, trichotillomania is subdivided into "automatic" versus "focused" hair pulling. Children are more often in the automatic, or unconscious, subtype and may not consciously remember pulling their hair. Other individuals may have focused, or conscious, rituals associated with hair pulling, including seeking specific types of hairs to pull, pulling until the hair feels "just right", or pulling in response to a specific sensation. Knowledge of the subtype is helpful in determining treatment strategies.

Treatment.

Treatment is based on a person's age. Most pre-school age children outgrow the condition if it is managed conservatively. In young adults, establishing the diagnosis and raising awareness of the condition is an important reassurance for the family and patient. Non-pharmacological interventions, including behavior modification programs, may be considered; referrals to psychologists or psychiatrists may be considered when other interventions fail. When trichotillomania begins in adulthood, it is often associated with other mental disorders, and referral to a psychologist or psychiatrist for evaluation or treatment is considered best. The hair pulling may resolve when other conditions are treated.

Psychotherapy.

Habit reversal training (HRT) has the highest rate of success in treating trichotillomania. HRT has also been shown to be a successful adjunct to medication as a way to treat trichotillomania. With HRT, the individual is trained to learn to recognize their impulse to pull and also teach them to redirect this impulse. In comparisons of behavioral versus pharmacologic treatment, cognitive behavioral therapy (including HRT) have shown significant improvement over medication alone. It has also proven effective in treating children. Biofeedback, cognitive-behavioral methods, and hypnosis may improve symptoms. Acceptance and Commitment Therapy (ACT) is also demonstrating promise in trichotillomania treatment. A systematic review from 2012 found tentative evidence for "movement decoupling".

Medication.

The United States Food and Drug Administration (FDA) has not approved any medications for trichotillomania treatment.  Medications can be used to treat trichotillomania. Treatment with clomipramine, a tricyclic antidepressant, was shown in a small double-blind study to improve symptoms, but results of other studies on clomipramine for treating trichotillomania have been inconsistent. Naltrexone may be a viable treatment. Fluoxetine and other selective serotonin reuptake inhibitors (SSRIs) have limited usefulness in treating trichotillomania, and can often have significant side effects. Behavioral therapy has proven more effective when compared to fluoxetine. There is little research on the effectiveness of behavioral therapy combined with medication, and robust evidence from high-quality studies is lacking. Acetylcysteine treatment stemmed from an understanding of glutamate's role in regulation of impulse control.  Different medications, depending on the individual, may increase hair pulling.

Devices.

Technology can be used to augment habit reversal training or behavioral therapy. Several mobile apps exist to help log behavior and focus on treatment strategies. There are also wearable devices that track the position of a user's hands. They produce sound or vibrating notifications so that users can track rates of these events over time.

Prognosis.

When it occurs in early childhood (before five years of age), the condition is typically self-limiting and intervention is not required. In adults, the onset of trichotillomania may be secondary to underlying psychiatric disturbances, and symptoms are generally more long-term.  Secondary infections may occur due to picking and scratching, but other complications are rare. Individuals with trichotillomania often find that support groups are helpful in living with and overcoming the disorder.

Epidemiology.

Although no broad-based population epidemiologic studies had been conducted as of 2009, the lifetime prevalence of trichotillomania is estimated to be between 0.6% and 4.0% of the overall population. With a 1% prevalence rate, 2.5 million people in the U.S. may have trichotillomania at some time during their lifetimes.  Trichotillomania is diagnosed in all age groups; onset is more common during preadolescence and young adulthood, with mean age of onset between 9 and 13 years of age, and a notable peak at 12–13. Among preschool children the genders are equally represented; there appears to be a female predominance among preadolescents to young adults, with between 70% and 93% of patients being female. Among adults, females typically outnumber males by 3 to 1.  "Automatic" pulling occurs in approximately three-quarters of adult patients with trichotillomania.

History.

Hair pulling was first mentioned by Aristotle in the fourth century B.C., was first described in modern literature in 1885, and the term "trichotillomania" was coined by the French dermatologist François Henri Hallopeau in 1889.  In 1987, trichotillomania was recognized in the Diagnostic and Statistical Manual of the American Psychiatric Association, third edition-revised (DSM-III-R).

Society and culture.

Support groups and internet sites can provide recommended educational material and help persons with trichotillomania in maintaining a positive attitude and overcoming the fear of being alone with the disorder.

Media.

A documentary film exploring trichotillomania, "Bad Hair Life", was the 2003 winner of the International Health & Medical Media Award for best film in psychiatry and the winner of the 2004 Superfest Film Festival Merit Award.  Trichster is a 2016 documentary that follows seven individuals living with trichotillomania, as they navigate the complicated emotions surrounding the disorder, and the effect it has on their daily lives.

Trichotillomania (TTM), also known as hair pulling disorder or compulsive hair pulling, is a mental disorder characterized by a long-term urge that results in the pulling out of one's hair. This occurs to such a degree that hair loss can be seen. A brief positive feeling may occur as hair is removed. Efforts to stop pulling hair typically fail. Hair removal may occur anywhere; however, the head and around the eyes are most common. The hair pulling is to such a degree that it results in distress. The disorder may run in families. It occurs more commonly in those with obsessive compulsive disorder. Episodes of pulling may be triggered by anxiety. People usually acknowledge that they pull their hair. On examination broken hairs may be seen. Other conditions that may present similarly include body dysmorphic disorder, however in that condition people remove hair to try to improve what they see as a problem in how they look. Treatment is typically with cognitive behavioral therapy. The medication clomipramine may also be helpful. Trichotillomania is estimated to affect one to four percent of people. Trichotillomania most commonly begins in childhood or adolescence. Women are affected about 10 times more often than men. The name was created by François Henri Hallopeau in 1889, from the Greek θρίξ/τριχ; "thrix" (meaning "hair"), along with τίλλειν; "tíllein" (meaning "to pull"), and μανία; "mania" (meaning "madness").

Bei der Trichotillomanie handelt es sich um eine komplexe Störung der Impulskontrolle, deren augenscheinlichstes Erscheinungsbild darin besteht, dass sich Betroffene die eigenen Haare ausreißen. Der Begriff ist zusammengesetzt aus griech. "thrix" = Haar, "tillein" = rupfen und "mania" = Raserei, Wahnsinn.


Description.

"A. salina" have three eyes and 11 pairs of legs and can grow to about in size. Their blood contains the pigment haemoglobin, which is also found in vertebrates. Males differ from females by having the second antennae markedly enlarged, and modified into clasping organs used in mating.

Life cycle.

Males have two reproductive organs. Prior to copulation the male clasps the female with his clasping organ, assuming a dorsal position. The claspers hold the female just anterior to the ovisac. Male and female may swim clasped together for a number of days. In this state, the movements of the swimming appendages of the pair beat in a co-ordinated fashion. The females can produce eggs either as a result of mating or via parthenogenesis. There are two types of eggs: thin-shelled eggs that hatch immediately and thick-shelled eggs, which can remain in a dormant state. These cysts can last for a number of years, and will hatch when they are placed in saltwater. Thick-shelled eggs are produced when the body of water is drying out, food is scarce, and the salt concentration is rising. If the female dies, the eggs develop further. Eggs hatch into nauplii that are about 0.5 mm in length. They have a single simple eye that only senses the presence and direction of light. Nauplii swim towards the light but adult individuals swim away from it. Later, the two more capable eyes develop but the initial eye also stays, resulting in three-eyed creatures.

Ecology.

In nature, they live in salt lakes. They are almost never found in an open sea, most likely because of the lack of food and relative defenselessness. However, "Artemia" have been observed in Elkhorn Slough, California, which is connected to the sea. However, North American populations are another species, "A. franciscana". Unlike most aquatic animals, "Artemia" swims upside down.  "Artemia" can live in water having much more or much less salt content than normal seawater. They tolerate salt amounts as high as 50%, which is nearly a saturated solution, and can live for several days in solutions very different from sea water, such as potassium permanganate or silver nitrate, while iodine—a frequent addition to edible salt—is harmful to them. The animal's colour depends on the salt concentration, with high concentrations giving them a slightly red appearance. In fresh water, "Artemia salina" dies after about an hour. It feeds mainly on green algae.  The species formerly lived in a number of salt works based around the Solent. They were observed only in the brine tanks where the concentrated salt water was held before boiling, but were probably also present in the salt pans. At least some of the salt harvesters thought they helped clean the brine and would deliberately introduce them into the tanks. With the decline of the salt works the species became extinct in England.

Uses.

The resilience of these creatures makes them ideal test samples in experiments. "Artemia" is one of the standard organisms for testing the toxicity of chemicals. In addition, the eggs survive for years. Hence it is possible to buy eggs and also ""Artemia" growing kits" for children, containing eggs, salt, food and most necessary tools. These have been most popularly marketed under the name "Sea-Monkeys". Children have the possibility to observe the life cycle of this interesting organism. Shops catering for aquarists also sell frozen "Artemia" as fish food. "Artemia" occurs in vast numbers in the Great Salt Lake where it is commercially important. However, nowadays it is believed that the brine shrimp of this lake is another species, "A. franciscana".

Taxonomy, distribution and conservation.

"Artemia salina" was first described (as "Cancer salinus") by Carl Linnaeus in his "" in 1758. This was based on a report by a German called Schlosser, who had found "Artemia" at Lymington, England. That population is now extirpated, although specimens collected there are retained in zoological museums.  As presently defined, "A. salina" is restricted to the Mediterranean region of Southern Europe, Anatolia and Northern Africa. Some populations elsewhere have formerly been referred to as this species, but are now recognized as separate, including "A. franciscana" of the Americas. That species has been widely introduced to places outside its native range, including the Mediterranean region, where it locally outcompetes the native "A. salina". This has already happened in parts of Portugal, Spain, France, Italy and Morocco.  An alternative taxonomic treatment is to recognized the extirpated English population as a species of its own, to which the name "A. salina" should be restricted. In that case the species native to the Mediterranean region of Southern Europe, Anatolia and Northern Africa can be referred to as "A. tunisiana", but at present most authorities reject this treatment and consider "A. tunisiana" as a synonym of "A. salina". Some have considered the North African population distinct and proposed that the name "A. tunisiana" should be restricted to it, but this is contradicted by genetic evidence, which shows that South European and North African populations belong to the same species.

Artemia salina is a species of brine shrimp – aquatic crustaceans that are more closely related to "Triops" and cladocerans than to true shrimp. It is a very old species that does not appear to have changed in.

Der Salinenkrebs ("Artemia salina"), manchmal auch "Salinkrebschen", "Artemia" oder "Salzkrebs" (Der Plural "Salzkrebschen" bezeichnet jedoch die übergeordnete Gattung), wird neben anderen Arten der Gattung "Artemia" in Zoohandlungen in Form von Frostfutter und „Eiern“ als Zierfischfutter verkauft. In natürlicher Umgebung ist er weltweit in salzigen Gewässern zu finden.


History.

The Pocket PC was an evolution from prior calculator-sized computers. Keystroke-programmable calculators which could do simple business and scientific applications were available by the 1970s. In 1982, Hewlett Packard's HP-75 incorporated a 1-line text display, an alphanumeric keyboard, HP BASIC language and some basic PDA abilities. The HP 95LX, HP 100LX and HP 200LX series packed a PC-compatible MS-DOS computer with graphics display and QWERTY keyboard into a palmtop format. The HP OmniGo 100 and 120 used a pen and graphics interface on DOS-based PC/GEOS, but was not widely sold in the United States. The HP 300LX built a palmtop computer on the Windows CE operating system, but not until the form factor and features of the Palm platform were adapted that it was named the Pocket PC.  Prior to the release of Windows Mobile 2003, third-party software was developed using Microsoft's eMbedded Visual Tools, eMbedded Visual Basic (eVB) and eMbedded Visual C (eVC). eVB programs can usually be converted fairly easily to NS Basic/CE. or to Basic4ppc.  According to Microsoft, the Pocket PC is "a handheld device that enables users to store and retrieve e-mail, contacts, appointments, tasks, play multimedia files, games, exchange text messages with Windows Live Messenger (formerly known as MSN Messenger), browse the Web, and more." (src: microsoft buyersguide)  From a technical standpoint, "Pocket PC" is a Microsoft specification that sets various hardware and software requirements for mobile devices bearing the "Pocket PC" label.  For instance, any device which is to be classified as a Pocket PC must:  The Pocket PC/Windows Mobile OS was superseded by Windows Phone on February 15, 2010 when the latter was announced at Mobile World Congress that year. No existing hardware was officially supported for a Windows Phone 7 upgrade. Additionally, not a single one of the thousands of apps available for Windows Mobile would run unaltered on Windows Phone.

Operating system versions.

Windows Mobile 6.5.

The first Windows Mobile 6.5 device was first shown in September 2009. Leaked ROMs surfaced in July 2009 for specific devices. The generic ROM images for Mobile 6.5 are also available as part of the officially distributed and freely downloadable development kit.  Several phones running Windows Mobile 6.1 can be updated to Windows Mobile 6.5.

Windows Mobile 6.1.

Microsoft's Windows Mobile 6.1 was announced on April 1, 2008 and introduced instant messaging-like texting. Windows Mobile 6.1 was built upon Windows CE 5.

Windows Mobile 6.

Microsoft's Windows Mobile 6, internally code-named 'Crossbow', was officially released by Microsoft on February 12, 2007. Mobile 6 was still based on Windows CE 5 and was effectively just a face-lift of Windows Mobile 5. With Mobile 6 also came Microsoft's new naming conventions and devices were no longer called Pocket PCs: devices with no phone abilities were named Windows Mobile Classic, and devices with phone abilities were named Windows Mobile Professional.

Windows Mobile 5.

Windows Mobile 5 for Pocket PC was based on Windows CE 5 and contained many fixes and improvements over Windows Mobile 2003.  Pocket PCs running prior versions of the operating system generally stored user-installed applications and data in RAM, which meant that if the battery was depleted the device would lose all of its data. Windows Mobile 5.0 solved this problem by storing all user data in persistent (flash) memory, leaving the RAM to be used only for running applications, as it would be on a desktop computer. As a result, Windows Mobile 5.0 Pocket PCs generally had more flash memory, and less RAM, compared to earlier devices.

Windows Mobile 2003.

Windows Mobile 2003 consisted of the Windows CE.NET 4.2 operating system bundled with scaled-down versions of many popular desktop applications, including Microsoft Outlook, Internet Explorer, Word, Excel, Windows Media Player, and others.  Windows Mobile 2003 Second Edition added native landscape, square screen and VGA support as well as other fixes and changes to those features already present in the original release of Windows Mobile 2003.

Windows CE 3.0.

Pocket PC 2000.

Pocket PC 2000 was launched April 2000, and ran Windows CE 3.0. Pocket PC 2000 featured a mobile version of Microsoft Office, a chief feature being the ability to password-protect Excel files.

Pocket PC 2002.

Pocket PC 2002 was launched October 2001, and was powered by Windows CE 3.0, as with its predecessor. Some Pocket PC 2002 devices were also sold as "Phone Editions", which included cell phone functionality in addition to the PDA abilities.

Vendors.

Before the Pocket PC brand was launched, there were other Windows-based machines of the same form factor made by HP, Philips, and others called Palm-size PCs. These devices ran Windows CE 2.0–2.11 and had an interface that was similar to the then-current desktop versions of Windows, such as Windows 98.  Pocket PCs were manufactured and sold by several different companies; the major manufacturers include HP (under the iPAQ and now defunct Jornada brands), Toshiba, Acer, Asus, Dell (under the now defunct Axim brand), Fujitsu Siemens, E-TEN, HTC, and ViewSonic. In mid-2003, Gateway Computers and JVC announced they would release Pocket PCs, but the projects were discontinued before a product was released. Prices in 2003 ranged from around for the high-end models, some of which are combined with cell phones, to $200 for low-end models. A $100–$200 model was rumored to be released within 2004 or early 2005, although the lowest price for a just-released Pocket PC never went under $300. Many companies ceased to sell PDA's by 2003–2004 because of a declining market. Major companies such as Viewsonic and Toshiba stopped producing new Pocket PCs.  Companies like O2, T-Mobile and Orange were marketing Pocket PCs that have integrated mobile telephony (smartphones). All users have to do is put in the SIM card and follow the wizard, to put their SIM contacts in the address book. An example is O2's Xda, or T-Mobile's MDA Compact. Both of these devices, while bearing the phone operator's logo, are manufactured by the dominant Pocket PC manufacturer HTC.  One of the more popular high-end consumer-market Pocket PCs was the Dell Axim x51v, which was discontinued in 2007. Hardware specs included 3.7" color TFT VGA display with 640x480 resolution, Intel XScaleTM PXA270 processor at 624 MHz, 336 MB of memory (256 MB flash, 64 MB SDRAM), integrated 802.11b and Bluetooth 1.2, integrated Intel 2700G multimedia accelerator with 16 MB video memory. Expansion was possible via CompactFlash Type II and SD slots (supporting SDIO Now!, SDIO and MMC cards). Included is a 1,100 mAh user replaceable battery (est. 4-6.5 hours, 2200 mAh also available).  Some Pocket PCs featured integrated GPS often combined with mobile phone functionality. Pocket PCs with built-in telephony differ from Windows Mobile Smartphone Edition devices in several respects, including the lack of a touchscreen on the latter. Some examples of current Pocket PCs with GPS integrated are the Fujitsu Siemens Pocket Loox N560, a high-end Pocket PC with a VGA screen and an integrated SiRF Star III GPS; the HTC TyTN, a small communicator with integrated slide in keyboard; the HP hw6945 and HP iPAQ hw6515 with integrated thumb-board, GPS and GSM/GPRS telephony; the HTC top of the line Universal, branded as the QTek 9000 (also branded by various telecommunications companies as the Orange SPV M5000, T-mobile MDA Pro, Vodafone VPA IV, O2 Xda Exec, i-Mate JasJar, Dopod 900).  A newer entrant into the Pocket PC market was Palm which sold devices like the Treo 700w/wx based on Windows Mobile 5.0 and featuring integrated telephony. Previous to this, Palm only produced PDAs running the Palm OS (as did the first versions of the Palm Treo).  HTC manufactures up to 80% of all phone enabled Windows Mobile devices for other companies (including HP and O2), as well as many non-phone Pocket PCs (for companies such as Dell, HP and Fujitsu Siemens). HTC is now marketing Windows Mobile devices under their own brand, as well as that of Dopod.

A Pocket PC (P/PC, PPC), also known by Microsoft as a Windows Mobile Classic device, is a kind of personal digital assistant (PDA) that runs the Windows Mobile operating system. It has some of the abilities of modern desktop PCs.

Pocket PC (zu dt. etwa "PC für die Westentasche") ist ein von Microsoft seit der CeBIT 2000 in Deutschland geprägter Begriff. Er bezeichnet sowohl eine Reihe von PDAs, die mit dem Betriebssystem Windows Mobile (oder einem seiner Vorläufer) betrieben werden, als auch zum Teil das verwendete Betriebssystem selbst.


Overview.

OLE allows an editing application to export part of a document to another editing application and then import it with additional content. For example, a desktop publishing system might send some text to a word processor or a picture to a bitmap editor using OLE. The main benefit of OLE is to add different kinds of data to a document from different applications, like a text editor and an image editor. This creates a Compound File Binary Format document and a master file to which the document makes reference. Changes to data in the master file immediately affect the document that references it. This is called "linking" (instead of "embedding").  OLE is also used for transferring data between different applications using drag and drop and clipboard operations.

History.

OLE 1.0.

OLE 1.0, released in 1990, was an evolution of the original Dynamic Data Exchange (DDE) concept that Microsoft developed for earlier versions of Windows. While DDE was limited to transferring limited amounts of data between two running applications, OLE was capable of maintaining active links between two documents or even embedding one type of document within another.  OLE servers and clients communicate with system libraries using virtual function tables, or VTBLs. The VTBL consists of a structure of function pointers that the system library can use to communicate with the server or client. The server and client libraries, OLESVR.DLL and OLECLI.DLL, were originally designed to communicate between themselves using the WM_DDE_EXECUTE message.  OLE 1.0 later evolved to become an architecture for software components known as the Component Object Model (COM), and later DCOM.  When an OLE object is placed on the clipboard or embedded in a document, both a visual representation in native Windows formats (such as a bitmap or metafile) is stored, as well as the underlying data in its own format. This allows applications to display the object without loading the application used to create the object, while also allowing the object to be edited, if the appropriate application is installed.  The Object Packager, a component of OLE, shipping from Windows 3.1 up to Windows XP allows a non-OLE object to be "packaged" so it can be embedded into an OLE client.

OLE 2.0.

OLE 2.0 was the next evolution of OLE, sharing many of the same goals as version 1.0, but was re-implemented on top of the COM instead of using VTBLs directly. New features were OLE automation, drag-and-drop, in-place activation and structured storage. Monikers evolved from OLE 1 object names, and provided a hierarchical object and resource naming system similar to URLs or URIs, which were independently invented. Windows now has merged the two technologies supporting a URL Moniker type, and a Moniker URL scheme.

OLE custom controls.

OLE custom controls were introduced in 1994 as a replacement for the now deprecated Visual Basic Extension controls. Instead of upgrading these, the new architecture was based on OLE. In particular, any container that supported OLE 2.0 could already embed OLE custom controls, although these controls cannot react to events unless the container supports this. OLE custom controls are usually shipped in the form of a dynamic link library with the.ocx extension. In 1996 all interfaces for controls (except IUnknown) were made optional to keep the file size of controls down, so they would download faster; these were then called ActiveX Controls.

Technical details.

OLE objects and containers are implemented on top of the Component Object Model; they are objects that can implement interfaces to export their functionality. Only the IOleObject interface is compulsory, but other interfaces may also need to be implemented if the functionality exported by those interfaces is required.  To ease understanding of what follows, some terminology has to be explained. The view status of an object is whether the object is transparent, opaque, or opaque with a solid background, and whether it supports drawing with a specified aspect. The site of an object is an object representing the location of the object in its container. A container supports a site object for every object contained.  What follows is a list of interfaces, grouped by the object that usually needs to implement them. Interfaces usually implemented by the OLE object are usually called on by the OLE container, and vice versa. Note that in the following list indentation indicates interface inheritance. All non-indented interfaces derive from IUnknown.

Competition.

OpenDoc technology tried to compete with OLE. Some of Microsoft's competitors considered OpenDoc to be more robust and easier to use; however, OpenDoc does have some known problems. OpenDoc allowed users to view and edit information across applications, directly in competition with Microsoft's proprietary OLE standard. In 1993 some Microsoft competitors established a consortium called the Component Integration Laboratories ("CIL") to develop OpenDoc as an open standard for cross-platform linking and embedding.  Microsoft required OLE compatibility as a condition of Microsoft's certification of an application's compatibility with Windows 95. Microsoft initially announced that applications using OpenDoc would be deemed compatible with OLE, and would receive certification for Windows 95. Microsoft later reversed the decision and said that applications using OpenDoc might not receive certification at all. Microsoft withheld specifications and debugged versions of OLE until after it had released its competing applications.

Interoperability.

Use of Microsoft Object Linking and Embedding (OLE) objects limits interoperability, because these objects are not widely supported in programs for viewing or editing files (e.g. embedding of other files inside the file, such as tables or charts from a spreadsheet application in a text document or presentation file). If software that understands an OLE object is not available, the object is usually replaced by a picture (bitmap representation of the object) or not displayed at all.

Object Linking & Embedding (OLE) is a proprietary technology developed by Microsoft that allows embedding and linking to documents and other objects. For developers, it brought OLE Control Extension (OCX), a way to develop and use custom user interface elements. On a technical level, an OLE object is any object that implements the codice_1 interface, possibly along with a wide range of other interfaces, depending on the object's needs.

Object Linking and Embedding (OLE, engl. "Objekt-Verknüpfung und -Einbettung") ist ein von Microsoft entwickeltes Objektsystem und Protokoll, das die Zusammenarbeit unterschiedlicher (OLE-fähiger) Applikationen und damit die Erstellung heterogener Verbunddokumente ermöglicht.


Studios.

NDR's studios in Hamburg are in two locations, both within the borough of Eimsbüttel: the television studios are in the quarter of Lokstedt while the radio studios are in the quarter of Harvestehude (though they are called "Funkhaus am Rothenbaum"), a little closer to the city centre. There are also regional studios, having both radio and television production facilities, in the state capitals Hanover, Kiel and Schwerin. The facility in Hanover is now called the Landesfunkhaus Niedersachsen. In addition NDR maintains facilities at ARD's national studios in Berlin.

Organization and finances.

Funding.

NDR is in part funded by the limited sale of on-air commercial advertising time; however, its principal source of income is the revenue derived from viewer and listener licence fees. As of 2015 the monthly fee due from each household for radio and television reception was €17.50. These fees are collected not directly by NDR but by a joint agency of ARD (and its member institutions), ZDF, and Deutschlandradio.

Stations.

NDR currently provides a number of services on its own or in co-operation with other broadcasters:

Musical organizations.

NDR has four musical organizations, including two orchestras, a chorus and a "big band":

Transmitters.

Mecklenburg-Vorpommern.

In Mecklenburg-Vorpommern, in the former East Germany, NDR programmes are broadcast from facilities owned by Media Broadcast GmbH, a former subsidiary of the Deutsche Telekom AG.

History.

"For 1924–1955 in detail, see Nordwestdeutscher Rundfunk."

Pre-war.

In 1924 broadcasting began in Hamburg, when "Norddeutsche Rundfunk AG" (NORAG) was created. In 1934 it was incorporated into the "Großdeutscher Rundfunk", the national broadcaster controlled by Joseph Goebbels's Propagandaministerium, as "Reichssender Hamburg".  In 1930, NORAG commissioned the Welte-Funkorgel – a large theatre organ custom-built by the firm of M. Welte & Sons to meet the specific acoustic requirements of radio broadcasting – and installed it in their radio studio (today the world's oldest such facility still in use) on Rothenbaumchaussee 132, Hamburg, where it continues to be played, now maintained by volunteers.

Post-war.

In the British Zone of occupied Germany, the military authorities quickly established "Radio Hamburg" to provide information to the population of the area.  The British Control Commission appointed Hugh Greene to manage the creation of public service broadcasting in their Zone. On 22 September 1945, "Radio Hamburg" became "Nordwestdeutscher Rundfunk", the single broadcasting organisation of the British Zone.

Länder control.

In 1948, the Control Commission transferred the Nordwestdeutscher Rundfunk (NWDR) to the control of the constituent Länder. At first, NWDR had just one radio station, later known as NWDR1. In 1950, it introduced a regional station for the north, "NWDR Nord" (later to become NDR2), and a regional station for the west, "NWDR West" (later WDR2).  That same year, NWDR became a founding member of ARD. The NWDR also played a founding role in launching 625-line television in Germany, starting broadcasts on 25 December 1952.

NWDR split.

In February 1955, North Rhine-Westphalia decided to establish its own broadcaster, whilst Hamburg, Lower Saxony, Schleswig-Holstein continued with the existing system. To this end, the NWDR was split into two broadcasters, Norddeutscher Rundfunk (NDR) in the north and Westdeutscher Rundfunk (WDR) in North Rhine-Westphalia.  NDR continued to operate out of Hamburg. The split was effective from 1 January 1956, although the station NWDR1 remained a joint operation with regional opt-outs.  The NWDR television service also remained a joint operation, from 1 April 1956 under the name " Nord- und Westdeutsche Rundfunkverband" (North and West German Broadcasting Federation – NWRV). NDR and WDR launched separate television services for their respective areas in 1961.

NDR history.

On 1 December 1956 NDR started its third radio channel, NDR3 (from 1962 to 1973, it was operated jointly with Sender Freies Berlin).  In 1958 Han Koller became the musical director of Hamburg's NDR Jazz Workshop, which became a popular radio broadcast. Numerous names in Jazz performed on these broadcasts including; Kenny Clarke, Lucky Thompson, Wes Montgomery, Johnny Griffin, Oscar Peterson, Ben Webster, Sahib Shihab, Carmell Jones, Lee Konitz, Cecil Payne, Slide Hampton, Phil Woods, Jazz Composers Orchestra, Howard Riley, Barry Guy, John Surman, the Kuhn Brothers and Barney Wilen. Some of these have been released since 1987, while the older ones only exist as rare bootlegs, sought after by many Jazz aficionados.  On 4 January 1965 NDR, Radio Bremen and SFB began a joint "third channel" television service, "Norddeutsches Fernsehen", later "Nord 3" and "N3". Since December 2001, this service is called "NDR Fernsehen". SFB started a separate TV channel for Berlin in 1992, called B1, later SFB1, now RBB Fernsehen.  In 1977, Gerhard Stoltenberg, the minister-president of Schleswig-Holstein unilaterally cancelled the "NDR-Staatsvertrag", the governing body of NDR. This caused a discussion how to organise broadcasting in the North German region.  In 1980, NDR signed a new convention with the three Länder, changing the pattern of broadcasting and creating new regional services. NDR1 was divided into three independent radio stations from 2 January 1981: NDR2 and NDR3 (now NDR Kultur) continued as regional stations.  These regional services were further subdivided with opt-outs for specific areas. "NDR 1 Niedersachsen" established regions based around Oldenburg-Ostfriesland-Bremen-Cuxhaven, Osnabrück-Emsland, greater Hanover, Braunschweig-southern Lower Saxony and northern Lower Saxony. "NDR 1 Welle Nord" was subdivided with studio centres in Flensburg, Heide, Norderstedt, Lübeck and Kiel.  On 30 September 1988 NDR introduced a teletext service on its "N3" television channel. Originally called "Nordtext", it became "NDR Text" on 2 December 2001. The teletext service also offers information for viewers in the Radio Bremen area under the title "Radio Bremen Text".  On 1 April 1989, NDR introduced its fourth radio service, NDR4. This service was later renamed "NDR4 Info" and since 2 June 2002 has been known as "NDR Info". The station is a news and information service for the whole NDR region.  On 1 January 1992, Mecklenburg-Vorpommern in the former East Germany joined NDR as the fourth state in the organisation. The area receives the main NDR radio and television stations, plus the regional "NDR 1 Radio mV", which has subregions based in Schwerin, Rostock, Neubrandenburg and Greifswald. In October of the same year, SFB in Berlin stopped relaying the "Nord 3" television service in favour of its own "Berlin 1" TV channel.  On 4 April 1994, NDR introduced "N-Joy Radio" (known simply as "N-Joy" since 2001), a radio station aimed at 14 to 29-year-old listeners.  On 3 October 1997, NDR3 was relaunched as "Radio 3", produced in co-operation with Ostdeutscher Rundfunk Brandenburg. At the end of 2000, SFB joined Radio 3. This arrangement lasted until ORB and SFB merged on 1 January 2003 and started íts own classical and culture network. NDR3 became "NDR Kultur" on 1 January 2003.  On 1 November 2001, NDR and Radio Bremen launched a joint radio station, "Nordwestradio", to serve Bremen and northwestern Lower Saxony. This service replaced "Radio Bremen 2" and control of the service remains with Radio Bremen.  As the organization responsible within the ARD consortium of German public-service broadcasters for overseeing the country's participation in the Eurovision Song Contest, NDR staged the 56th annual contest which was held in Düsseldorf on 10–14 May 2011, outside their own broadcasting area.

Norddeutscher Rundfunk (NDR; Northern German Broadcasting) is a public radio and television broadcaster, based in Hamburg. In addition to the city-state of Hamburg, NDR transmits for the German states of Lower Saxony, Mecklenburg-Vorpommern and Schleswig-Holstein. NDR is a member of the ARD consortium.

Der Norddeutsche Rundfunk (NDR) ist eine gemeinsame Landesrundfunkanstalt für die Freie und Hansestadt Hamburg und für die Länder Mecklenburg-Vorpommern, Niedersachsen und Schleswig-Holstein. Der Sitz ist in Hamburg.


IPTC Standards.

Photo metadata.

The IPTC defined a set of metadata properties that can be applied to images, part of a broader standard developed in the early 1990s and known as the IPTC Information Interchange Model (IIM). Embedded IIM image information is often referred to as an "IPTC header". This basic set of metadata fields is branded as "IPTC Core", in 2008 a second set branded as "IPTC Extension" was developed.  The Extensible Metadata Platform (XMP) has largely superseded IIM's image file header structure, but the properties of the IPTC Core are synchronized between the technical structures of XMP and IIM by a vast majority of imaging software.  Because of its nearly universal acceptance among photographers — even amateurs — this is by far IPTC's most widely used standard.

IPTC NewsML-G2-Standards Family.

Using XML and the W3C’s model for the Semantic Web, in 2008 IPTC launched a new series of standards that feature modular construction and many opportunities for embedding metadata. This allows developers to build applications that use only the parts of the IPTC NewsML-G2-Standards that are required by the customer, and that reduce programming costs by re-using XML and metadata modules. Further the NewsML-G2-Standards extend the scope of exchange formats beyond news content, they include event data and well organised information about persons, organisations, points of interest, geopolitical areas or abstract concepts.  These members of the family of standards are available now: NewsML-G2, EventsML-G2 and SportsML-G2. Although they have different roles within the news industry they share much of the date model and the same XML coding.

NewsML-G2.

NewsML-G2 acts as an envelope and organizer so that news providers can create single news items — text, photos, video or anything else — and bundle them into concise cohesive packages than can be automatically processed by web CMSs or newsroom systems. The content and relationships of the individual news items can be described using a rich set of metadata.  NewsML-G2 is not a text or image mark-up format. For example, it does not contain paragraph or headline tagging. Rather, it is an envelope and organizer that does not, by itself, act as a content format. For text article formatting, IPTC mentions News Industry Text Format (NITF) or XHTML as common examples.  NewsML-G2 is used by several large international news agencies, including Agence France-Presse, Associated Press, Austria Presse Agentur, Deutsche Presse-Agentur, Thomson Reuters, and others.

EventsML-G2.

EventsML-G2 optimises the sharing of event information such as meetings, sports events, elections, and even rocket launches — virtually any announced activity that can be broadly classified as an "event." Using XML and metadata, EventsML-G2 allows news providers to create rich descriptions of events plus information about planned coverage, and then share that information with web sites, databases, newsrooms or other customers.  EventsML-G2 is not a calendaring standard, but rather a way for news agencies to share event information to populate their own calendars. The events need not have fixed starting or ending dates, nor do they even need to have a fixed length.

SportsML-G2.

SportsML-G2 is a convenient way to share sports statistics in a concise, unambiguous way. All major sports are supported, and certain sports that are known for rich or especially complex statistics (such as baseball) can use special add-on modules. SportsML-G2 has found wide usage outside the news industry; among the user communities are sports teams, fantasy sports leagues, sports betting firms and sports historians. SportsML-G2 is the newer sibling of SportsML.  Version 2.0 of SportsML-G2 was released in October 2008.

NewsCodes.

NewsCodes is the branding of Controlled Vocabularies created and maintained by IPTC. A set of them can be used to classify news content - regardless of the media type - and another set is used to support the functionality of IPTC's news exchange format standards.

NewsML 1.

NewsML 1 is an XML standard developed by the IPTC to provide a media-independent, structural enveloping framework for multi-media news.  It has also been adopted as Japanese Industrial Standards (JIS) X7201:2005.  Although superseded in 2008 by NewsML-G2, NewsML 1 (as the original NewsML is now known) remains popular outside North America (especially in Asia) and IPTC plans to support this standard as "NewsML 1.x" indefinitely.

ninjs.

ninjs standardizes the representation of news in JSON - a lightweight, easy-to-parse, data interchange format. The format covers the data interchange by APIs and documents in content management systems like search engines.

NITF - News Industry Text Format.

News Industry Text Format (NITF) is an XML specification published by the IPTC that is designed to standardize the content and structure of text-based news articles.

RightsML.

RightsML is IPTC's Rights Expression Language for news media and is based on ODRL.

rNews.

rNews is a standard for using semantic markup to annotate online news. It defines a data model for embedding machine-readable publishing metadata in web documents and a set of suggested implementations. Some properties of this standard have been adopted by Schema.org for its metadata schema.

SportsML.

SportsML is an XML news exchange standard for sharing sports statistics in a concise, unambiguous way. All major sports are supported, and certain sports that are known for rich or especially complex statistics (such as baseball) can use special add-on modules. SportsML has found wide usage outside the news industry; among the user communities are sports teams, fantasy sports leagues, sports betting firms and sports historians.  In June 2008, the IPTC approved SportsML-G2 as a parallel standard to SportsML. Although SportsML-G2 is built from standardized XML modules that are used by other IPTC G2 standards, both standards effectively accomplish the same task.

IPTC 7901.

IPTC 7901 is still a widely used format for plain text news, despite being 30 years old. It is a close relative of the Newspaper Association of America North American standard ANPA-1312, and uses similar control and other special characters to create a file that can be used to drive computerized news editing systems, photo typesetters or even teleprinter machines.

The International Press Telecommunications Council (IPTC), based in London, United Kingdom, is a consortium of the world's major news agencies, other news providers and news industry vendors and acts as the global standards body of the news media.

Der International Press Telecommunications Council (IPTC) ist der Weltverband von Nachrichtenagenturen und Zeitungen für die technische Normierung des Nachrichtenaustausches. Ursprünglich wurde die Organisation mit Sitz in London 1965 gegründet, um die Interessen von Presse und Nachrichtenagenturen im Bereich Telekommunikation zu wahren.


Early life and education.

Thompson was born in New Orleans. When asked how he learned to program, Thompson stated, "I was always fascinated with logic and even in grade school I'd work on arithmetic problems in binary, stuff like that. Just because I was fascinated." Thompson received a Bachelor of Science in 1965 and a Master's degree in 1966, both in Electrical Engineering and Computer Science, from the University of California, Berkeley, where his master's thesis advisor was Elwyn Berlekamp.

Career and research.

Thompson was hired by Bell Labs in 1966. In the 1960s at Bell Labs, Thompson and Dennis Ritchie worked on the Multics operating system. While writing Multics, Thompson created the Bon programming language. He also created a video game called "Space Travel". Later, Bell Labs withdrew from the MULTICS project. In order to go on playing the game, Thompson found an old PDP-7 machine and rewrote "Space Travel" on it. Eventually, the tools developed by Thompson became the Unix operating system: Working on a PDP-7, a team of Bell Labs researchers led by Thompson and Ritchie, and including Rudd Canaday, developed a hierarchical file system, the concepts of computer processes and device files, a command-line interpreter, pipes for easy inter-process communication, and some small utility programs. In 1970, Brian Kernighan suggested the name "Unix", in a pun on the name "Multics". After initial work on Unix, Thompson decided that Unix needed a system programming language and created B, a precursor to Ritchie's C.  In the 1960s, Thompson also began work on regular expressions. Thompson had developed the CTSS version of the editor QED, which included regular expressions for searching text. QED and Thompson's later editor ed (the standard text editor on Unix) contributed greatly to the eventual popularity of regular expressions, and regular expressions became pervasive in Unix text processing programs. Almost all programs that work with regular expressions today use some variant of Thompson's notation. He also invented Thompson's construction algorithm used for converting regular expression into nondeterministic finite automaton in order to make expression matching faster.

1970s.

Throughout the 1970s, Thompson and Ritchie collaborated on the Unix operating system; they were so influential on Research Unix that Doug McIlroy later wrote, "The names of Ritchie and Thompson may safely be assumed to be attached to almost everything not otherwise attributed." In a 2011 interview, Thompson stated that the first versions of Unix were written by him, and that Ritchie began to advocate for the system and helped to develop it:  Feedback from Thompson's Unix development was also instrumental in the development of the C programming language. Thompson would later say that the C language "grew up with one of the rewritings of the system and, as such, it became perfect for writing systems".  In 1975, Thompson took a sabbatical from Bell Labs and went to his alma mater, UC Berkeley. There, he helped to install Version 6 Unix on a PDP-11/70. Unix at Berkeley would later become maintained as its own system, known as the Berkeley Software Distribution (BSD).  Ken Thompson wrote a chess-playing program called "chess" for the first version of Unix (1971). Later, along with Joseph Condon, Thompson created the hardware-assisted program Belle, a world champion chess computer. He also wrote programs for generating the complete enumeration of chess endings, known as endgame tablebases, for all 4, 5, and 6-piece endings, allowing chess-playing computer programs to make "perfect" moves once a position stored in them is reached. Later, with the help of chess endgame expert John Roycroft, Thompson distributed his first results on CD-ROM. In 2001, the "ICGA Journal" devoted almost an entire issue to Ken Thompson's various contributions to computer chess.

1980s.

Throughout the 1980s, Thompson and Ritchie continued revising Research Unix, which adopted a BSD codebase for the 8th, 9th, and 10th editions. In the mid-1980s, work began at Bell Labs on a new operating system as a replacement for Unix. Thompson was instrumental in the design and implementation of the Plan 9 from Bell Labs, a new operating system utilizing principles of Unix, but applying them more broadly to all major system facilities. Some programs that were part of later versions of Research Unix, such as mk and rc, were also incorporated into Plan 9.  Thompson tested early versions of the C++ programming language for Bjarne Stroustrup by writing programs in it, but later refused to work in C++ due to frequent incompatibilities between versions. In a 2009 interview, Thompson expressed a negative view of C++, stating, "It does a lot of things half well and it's just a garbage heap of ideas that are mutually exclusive."

1990s.

In 1992, Thompson developed the UTF-8 encoding scheme together with Rob Pike. UTF-8 encoding has since become the dominant character encoding for the World Wide Web, accounting for more than 90% of all web pages in 2019.  In the 1990s, work began on the Inferno operating system, another research operating system that was based around a portable virtual machine. Thompson and Ritchie continued their collaboration with Inferno, along with other researchers at Bell Labs.

2000s.

In late 2000, Thompson retired from Bell Labs. He worked at Entrisphere, Inc. as a fellow until 2006 and now works at Google as a Distinguished Engineer. Recent work has included the co-design of the Go programming language. Referring to himself along with the other original authors of Go, he states:  According to a 2009 interview, Thompson now uses a Linux-based operating system.

Awards.

National Academies.

In 1980, Thompson was elected to the National Academy of Engineering for "designing UNIX, an operating system whose efficiency, breadth, power, and style have guided a generation's exploitation of minicomputers". In 1985 he was elected a Member of the National Academy of Sciences (NAS).

Turing Award.

In 1983, Thompson and Ritchie jointly received the Turing Award "for their development of generic operating systems theory and specifically for the implementation of the UNIX operating system". His acceptance speech, "Reflections on Trusting Trust", presented the backdoor attack now known as the "Thompson hack" or trusting trust attack, and is widely considered a seminal computer security work in its own right.

IEEE Richard W. Hamming Medal.

In 1990, both Thompson and Dennis Ritchie received the IEEE Richard W. Hamming Medal from the Institute of Electrical and Electronics Engineers (IEEE), "for the origination of the UNIX operating system and the C programming language".

Fellow of the Computer History Museum.

In 1997, both Thompson and Ritchie were inducted as Fellows of the Computer History Museum for "the co-creation of the UNIX operating system, and for development of the C programming language".

National Medal of Technology.

On April 27, 1999, Thompson and Ritchie jointly received the 1998 National Medal of Technology from President Bill Clinton for co-inventing the UNIX operating system and the C programming language which together have "led to enormous advances in computer hardware, software, and networking systems and stimulated growth of an entire industry, thereby enhancing American leadership in the Information Age".

Tsutomu Kanai Award.

In 1999, the Institute of Electrical and Electronics Engineers chose Thompson to receive the first Tsutomu Kanai Award "for his role in creating the UNIX operating system, which for decades has been a key platform for distributed systems work".

Japan Prize.

In 2011, Thompson, along with Dennis Ritchie, was awarded the Japan Prize for Information and Communications for the pioneering work in the development of the Unix operating system.

Personal life.

Ken Thompson is married and has a son.

References.

Sources

Kenneth Lane Thompson (born February 4, 1943) is an American pioneer of computer science. Thompson worked at Bell Labs for most of his career where he designed and implemented the original Unix operating system. He also invented the B programming language, the direct predecessor to the C programming language, and was one of the creators and early developers of the Plan 9 operating system. Since 2006, Thompson has worked at Google, where he co-invented the Go programming language.

Kenneth „Ken“ Lane Thompson (* 4. Februar 1943 in New Orleans, Louisiana) ist ein US-amerikanischer Informatiker, der unter anderem maßgeblich an der Entwicklung des Unix-Betriebssystems beteiligt war. Er erhielt für seine Arbeiten zahlreiche Ehrungen und Auszeichnungen, darunter den Turing Award.


History.

Canoe slalom racing started in Europe and in the 1940s, the International Canoe Federation (ICF) was formed to govern the sport. The first World Championships were held in 1949 in Switzerland. From 1949 to 1999, the championships were held every odd-numbered year and have been held annually in non-Summer Olympic years since 2002. Folding kayaks were used from 1949 to 1963; and in the early 1960s, boats were made of fiberglass and nylon. Boats were heavy, usually over 65 pounds (30 kilos). With the advent of kevlar and carbon fiber being used in the 1970s, the widths of the boats were reduced by the ICF, and the boats were reduced in volume to pass the gates, and boats have become much lighter and faster.  From 1949 to 1977, all World Championships were held in Europe. The first World Championship held in North America was held at Jonquière, in Québec, Canada, in 1979. It has been a regular Olympic sport since 1992.  In 2020 during the Tokyo Olympics, C2 men loses its status as an official olympic event and is to be replaced by C1 women.

Rules.

Each gate consists of two poles hanging from a wire strung across the river. There are 18-25 numbered gates in a course, of which 6 or 8 must be upstream gates, and they are colored as either green (downstream) or red (upstream), indicating the direction they must be negotiated. Upstream gates are always placed in eddies, where the water is flat or moving slightly upstream; the paddler enters an eddy from the main current and paddles upstream through the gate. Downstream gates may also be placed in eddies, to increase the difficulty, and downstream gates in the current can be offset to alternating sides of the current, requiring rapid turns in fast-moving water.  Most slalom courses take 80 to 120 seconds to complete for the fastest paddlers. Depending on the level of competition, difficulty of the course, degree of water turbulence. and ability of the other paddlers, times can go up to 200 seconds.  In international competitions (World Cups, World Championships, Olympic Games) each competitor does two runs in the qualification round, called the "heats"; the time of the faster run gives the qualification result. Depending on the number of participants in the event, 10 to 40 boats make it through to the semi-final; this consists of one run on a different course. The fastest semi-final boats, the number determined by the number of participants, make it through to the final, where they navigate the semi-final course once more. Their ranking within the final group is based on the time of that last run alone.  If the competitor's boat, paddle or body touches either pole of the gate, a time penalty of two seconds is added. If the competitor misses a gate completely, deliberately pushes the gate to pass through, goes through the gate in the wrong direction or upside-down, or goes through it in the wrong order, a 50-second penalty is given. Only one penalty can be incurred on each gate, and this will be taken as the highest one.  There are currently four Olympic Medal events:  In the 1960s and early 1970s, boats were made of heavy fiberglass and nylon. The boats were high volume and weighed over 30 pounds (14 kilos). In the early 1970s Kevlar was used and the boats became lighter as well as the volume of the boats was being reduced almost every year as new designs were made. A minimum boat weight was introduced to equalize competition when super light materials began to affect race results. The ICF also reduced the width of the boats in the early 1970s. The gates were hung about 10 cm above the water. When racers began making lower-volume boats, the gates were raised in response to fears that new boats would be of such low volume as to create a hazard to the paddler. Their low-volume sterns allow the boat to slice through the water in a quick turn, or "pivot".  Typically, new racing boats cost between $1,200 and $2,500 (or $850 onwards for the cheapest constructions in fiberglass). Usually boats are made with carbon fiber, Kevlar and fiberglass cloth, using epoxy or polyester resin to hold the layers together. Foam sandwich construction in between layers of carbon, Kevlar, or Aramid is another technique in use to increase the stiffness of slalom boats.  In 2005 the minimum length of these boats was reduced from 4 meters down to 3.5 meters, causing a flurry of new, faster boat designs which are able to navigate courses with more speed and precision. The shorter length also allows for easier navigation and less boat damage in the smaller manmade river beds that are prevalent in current elite competitions.  Boat design progression is rather limited year to year. Directly from the 2017 ICF Canoe Slalom Rules:  There are rules governing almost every aspect of slalom equipment used in major competition, including sponsor advertisement. Some of these rules vary from country to country; each national canoe and kayak governing body publishes its own variation of the rules.

Courses.

Slalom courses are usually on Class II - IV whitewater. Some courses are technical, containing many rocks. Others are on stretches containing fewer rocks and larger waves and holes.

Olympics.

Slalom canoeing made its Olympic debut in 1972 in Augsburg, West Germany, for the Munich Games. It was not seen again until 1992 in La Seu d'Urgell as part of the 1992 Olympics in Barcelona, Spain. Since then, slalom paddling has been a regular Olympic event in the following locations:  The 1972 Olympics in Augsburg were held on an artificial whitewater course. The Augsburg Eiskanal set the stage for the future of artificial course creation. With the exception of the altered river bed of the Ocoee River in 1996, every Olympic venue has been a manmade concrete channel. Since the late 1980s, artificial course creation has surged; now most countries that field Olympic slalom teams have more than one artificial course to train on. Artificial river creation has evolved and new courses have fewer issues than some of the initial designs.

Canoe slalom (previously known as whitewater slalom) is a competitive sport with the aim to navigate a decked canoe or kayak through a course of hanging downstream or upstream gates on river rapids in the fastest time possible. It is one of the two kayak and canoeing disciplines at the Summer Olympics, and is referred to by the International Olympic Committee (IOC) as Canoe/Kayak Slalom. The other Olympic canoeing discipline is canoe sprint. Wildwater canoeing is a non-Olympic paddlesport.

Kanuslalom ist eine Wettkampfdisziplin des Kanusports. Ziel ist es, eine mit Toren festgelegte Strecke auf schnell fließenden Wasser in kürzester Zeit fehlerfrei zu befahren.


History.

Animal and Human trading.

In 1863, the elder Hagenbeck began collecting exotic animals that came through Hamburg's port. By the 1870s, the trade had proved more lucrative than his fish shop, and Hagenbeck had become one of the most prominent exotic animal traders in all of Europe. In 1874, the younger Hagenbeck traveled around the world collecting animals. Among his collections, however, were also human beings whom he exhibited in "human zoos". Hagenbeck decided to exhibit Samoan and Sami people (Laplanders) as "purely natural" populations. The Sami were presented with their tents, weapons, and sleds, beside a group of reindeer. In 1874, Hagenbeck opened a zoo facility in Hamburg, called Carl Hagenbeck's Tierpark, while he continued exhibiting humans. In 1876, he began exhibiting Nubians all across Europe. He also dispatched an agent to Labrador to secure a number of "Esquimaux" (Inuit) from the settlement of Hebron; these Inuit (see Abraham Ulrikab) were exhibited in the Hamburg Tierpark.  Though initially popular, Hagenbeck's shows gradually began to decline in popularity, especially once the photograph became more and more common, and Hagenbeck's exhibits began to look less and less real in comparison. After one exhibit, Hagenbeck was left with a large number of elephants and no one to purchase them. Unable to sell, he started a circus. To counter the declining popularity of his human zoos, Hagenbeck began working on making his displays more realistic, techniques that would later influence the animal zoo.

Panorama exhibits.

In the 1890s Hagenbeck created his first "panorama" exhibit and patented the idea in 1896. The display was the "Northern Panorama", the foreground featured seals and walruses in a pool. Hidden from the zoo's patrons was a moat behind the pool. Beyond the moat were reindeer, and beyond a second hidden moat were polar bears. By hiding the moats, the animals appeared to be together in one landscape.  In 1907, Hagenbeck constructed a new facility outside of Hamburg which he called Tierpark Hagenbeck (without the 'H' that was in Thierpark) which is still the location of the facility today. Hagenbeck sought to design the entire zoo with his panorama system. He also sought to demonstrate that animals from warmer climates did not need to live in expensive, humid, foreboding buildings. Instead, Hagenbeck again sought to make his displays realistic.  Using data that he had compiled running his circus, Hagenbeck had estimates of how high and far different animals could leap. Using this data, he built moats filled with water or an empty pit that he determined the animals could not cross. Using moats to separate animals that did not swim, one could look across an expanse of the zoo and see many animals at once, as if in the wild. Previously, zoos had not grouped animals by species, but Hagenbeck revolutionized the layout of zoos, grouping his animals by species. Hagenbeck's design was a popular success. In 1911, Hagenbeck designed the Rome Zoo in the same style. In 1913, he designed the first monkey-rock exhibit, in this case an artificial crag with a moat. The rock was populated by around 200 hamadryas baboons.  Hagenbeck called his design an animal paradise where "animals would live beside each other in harmony and where the fight for survival would be eliminated."

World War I and II.

Hagenbeck died in 1913, but his zoo remained popular until the political situation in Europe swept the zoo into hard times. During World War I many of the keepers were drafted into the German army. Because the military had taken horses from civilians for use at the front, many of Hagenbeck's animals were rented out for use as draught animals for hauling coal and wood on home deliveries. It was not unusual to see elephants and trained bears hitched up to heavy wagons. After the war, the zoo closed for two years as Germany entered into a deep depression. Then during the Bombing of Hamburg in World War II the original zoo was destroyed. After the war the zoo was rebuilt. The private zoo is still run by the Hagenbeck family.

Monkey escape.

In July 1956, forty five rhesus monkeys escaped from the zoo and ran wild in Hamburg. The incident resulted in calls for help from shocked housewives who met monkeys in their bedrooms and bathtubs. Some of the monkeys sat in trees and chattered excitedly, showing each other toothpaste, soap bars and bathroom utensils which they had grabbed. Managers of the zoo reported that more than two dozen of the long-tailed Indian monkeys had been caught by policemen, firemen, zoo keepers and schoolchildren.

Antje the walrus.

In 1976, the zoo acquired a female Pacific talking walrus which Hagenbeck named Antje after his sister. Antje became the logo of the north German television network NDR from 1983 to 1996. In 2003, Antje died and is now stuffed and on display at the zoological museum of Hamburg. Soon after, the children's cartoon "Antje, Tiger und Bär" aired on German television featuring a blue walrus protagonist based on Antje and designed by children's author Janosch. In 2013, Tierpark Hagenbeck gained a male and three female walruses from Moscow.

The Tierpark Hagenbeck is a zoo in Stellingen, a quarter in Hamburg, Germany. The collection began in 1863 with animals that belonged to Carl Hagenbeck Sr. (1810–1887), a fishmonger who became an amateur animal collector. The park itself was founded by Carl Hagenbeck Jr. in 1907. It is known for being the first zoo to use open enclosures surrounded by moats, rather than barred cages, to better approximate animals' natural environments.

Der Tierpark Hagenbeck (ehemals "Hagenbecks Tierpark") ist ein Tierpark in Hamburg. Der im Stadtteil Stellingen gelegene Tierpark ist ebenso wie das 2007 daneben eröffnete Tropen-Aquarium Hagenbeck in Familienbesitz. Er geht auf die im Jahr 1863 von Carl Hagenbeck sen. begründete "Carl Hagenbeck’s Handels-Menagerie" am Spielbudenplatz im Stadtteil St. Pauli zurück, die 1866 von Carl Hagenbeck jun. zum Neuen Pferdemarkt verlegt wurde. Am 7. Mai 1907 eröffnete Hagenbeck den weltweit ersten Tierpark ohne Gitter am jetzigen Standort außerhalb der Stadt. Der Tierpark gehört mittlerweile zum Hamburger Bezirk Eimsbüttel und wird im Volksmund zumeist nur als "Hagenbeck" ("zu Hagenbeck gehen") bezeichnet. Er ist Gastgeber und Handlungsort der NDR-Fernsehserie "Leopard, Seebär & Co."


Early life.

Frederick William was born in Potsdam in 1770 as the son of Frederick William II of Prussia and Frederica Louisa of Hesse-Darmstadt. He was considered to be a shy and reserved boy, which became noticeable in his particularly reticent conversations distinguished by the lack of personal pronouns. This manner of speech subsequently came to be considered entirely appropriate for military officers. He was neglected by his father during his childhood and suffered from an inferiority complex his entire life.  As a child, Frederick William's father (under the influence of his mistress, Wilhelmine Enke, Countess of Lichtenau) had him handed over to tutors, as was quite normal for the period. He spent part of the time living at Paretz, the estate of the old soldier Count Hans von Blumenthal who was the governor of his brother Prince Heinrich. They thus grew up partly with the Count's son, who accompanied them on their Grand Tour in the 1780s. Frederick William was happy at Paretz, and for this reason in 1795 he bought it from his boyhood friend and turned it into an important royal country retreat. He was a melancholy boy, but he grew up pious and honest. His tutors included the dramatist Johann Engel.  As a soldier, he received the usual training of a Prussian prince, obtained his lieutenancy in 1784, became a lieutenant colonel in 1786, a colonel in 1790, and took part in the campaigns against France of 1792–1794. On 24 December 1793, Frederick William married Louise of Mecklenburg-Strelitz, who bore him ten children. In the "Kronprinzenpalais" (Crown Prince's Palace) in Berlin, Frederick William lived a civil life with a problem-free marriage, which did not change even when he became King of Prussia in 1797. His wife Louise was particularly loved by the Prussian people, which boosted the popularity of the whole House of Hohenzollern, including the King himself.

Reign.

Frederick William succeeded to the throne on 16 November 1797. He also became, in personal union, the sovereign prince of the Principality of Neuchâtel (1797–1806 and again 1813–1840). At once, the new King showed that he was earnest of his good intentions by cutting down the expenses of the royal establishment, dismissing his father's ministers, and reforming the most oppressive abuses of the late reign. He had the Hohenzollern determination to retain personal power but not the Hohenzollern genius for using it. Too distrustful to delegate responsibility to his ministers, he greatly reduced the effectiveness of his reign since he was forced to assume the roles he did not delegate. This is a main factor of his inconsistent rule.  Disgusted with the moral debauchery of his father's court (in both political intrigues and sexual affairs), Frederick William's first, and most successful early endeavor was to restore the moral legitimacy to his dynasty. The eagerness to restore dignity to his family went so far that it nearly caused sculptor Johann Gottfried Schadow to cancel the expensive and lavish "Prinzessinnengruppe" project, which was commissioned by the previous monarch Frederick William II. He was quoted as saying the following, which demonstrated his sense of duty and peculiar manner of speech:  At first Frederick William and his advisors attempted to pursue a policy of neutrality in the Napoleonic Wars. Although they succeeded in keeping out of the Third Coalition in 1805, eventually Frederick William was swayed by the attitude of the queen, who led Prussia's pro-war party, and entered into war in October 1806. On 14 October 1806, at the Battle of Jena-Auerstädt, the French effectively decimated the effectiveness and functionality of the Prussian army led by Frederick William, and the Prussian army collapsed entirely soon after. Napoleon occupied Berlin in late October. The royal family fled to Memel, East Prussia, where they fell on the mercy of Emperor Alexander I of Russia.  Alexander, too, suffered defeat at the hands of the French, and at Tilsit on the Niemen France made peace with Russia and Prussia. Napoleon dealt with Prussia very harshly, despite the pregnant Queen's personal interview with the French emperor which was believed would soften the blow of defeat. Instead, Napoleon took much less mercy on the Prussians than what was expected. Prussia lost many of its Polish territories, as well as all territory west of the Elbe, and had to finance a large indemnity and to pay for French troops to occupy key strong points within the Kingdom.  Although the ineffectual King himself seemed resigned to Prussia's fate, various reforming ministers, such as Baron vom Stein, Prince von Hardenberg, Scharnhorst, and Count Gneisenau, set about reforming Prussia's administration and military, with the encouragement of Queen Luise (who died, greatly mourned, in 1810).  In 1813, following Napoleon's defeat in Russia, Frederick William turned against France and signed an alliance with Russia at Kalisz, although he had to flee Berlin, still under French occupation. Prussian troops played a key part in the victories of the allies in 1813 and 1814, and the King himself travelled with the main army of Prince Schwarzenberg, along with Alexander of Russia and Francis of Austria.  At the Congress of Vienna, Frederick William's ministers succeeded in securing important territorial increases for Prussia, although they failed to obtain the annexation of all of Saxony, as they had wished. Following the war, Frederick William turned towards political reaction, abandoning the promises he had made in 1813 to provide Prussia with a constitution.

Prussian Union of churches.

Frederick William was determined to unify the Protestant churches, to homogenize their liturgy, their organization and even their architecture. The long-term goal was to have fully centralized royal control of all the Protestant churches in the Prussian Union of churches. The merging of the Lutheran and Calvinist (Reformed) confessions to form the United Church of Prussia highly controversial. Angry responses included a large and well-organized opposition. Especially the "Old Lutherans" in Silesia refused to abandon their liturgical traditions. The crown responded by attempting to silence protest. The stubborn Lutheran minority was coerced by military force, the confiscation of their churches and the imprisonment or exile of their pastors. By 1834 outward union was secured on the basis of common worship but separate symbols. The opponents of the measure being forbidden to form communities of their own. Many left Prussia. The King's unsuccessful counterattack worsened tensions at the highest levels of government. The crown's aggressive efforts to restructure religion were unprecedented in Prussian history. In a series of proclamations over several years the "Church of the Prussian Union" was formed, bringing together the majority group of Lutherans, and the minority group of Reformed Protestants. The main effect was that the government of Prussia had full control over church affairs, with the king himself recognized as the leading bishop.  In 1824 Frederick William III remarried (morganatically) Countess Auguste von Harrach, Princess of Liegnitz. They had no children.  In 1838 the king distributed large parts of his farmland at Erdmannsdorf Estate to 422 protestant refugees from the Austrian Zillertal who built Tyrolian style farmhouses in the Silesian village.

Death.

Frederick William III died on 7 June 1840 in Berlin, from a fever, survived by his second wife. His eldest son, Frederick William IV, succeeded him. Frederick William III is buried at the Mausoleum in Schlosspark Charlottenburg, Berlin.

Further reading.

This article |was originally copied from "The Encyclopædia Britannica, Eleventh Edition" (1911).

Frederick William III (; 3 August 1770 – 7 June 1840) was king of Prussia from 1797 to 1840. He ruled Prussia during the difficult times of the Napoleonic Wars. Steering a careful course between France and her enemies, after a major military defeat in 1806, he was humiliated by Napoleon, and Prussia was stripped of recent gains and forced to pay huge financial penalties. The king reluctantly joined the coalition against Napoleon in the "Befreiungskriege". Following Napoleon's defeat, he took part in the Congress of Vienna, which assembled to settle the political questions arising from the new, post-Napoleonic order in Europe. His major interests were internal, the reform of Prussia's Protestant churches. He was determined to unify the Protestant churches, to homogenize their liturgy, their organization, and even their architecture. The long-term goal was to have fully centralized royal control of all the Protestant churches in the Prussian Union of Churches. The king was said to be extremely shy and indecisive. His wife Queen Louise (1776–1810) was his most important political advisor. She led a very powerful group that included Baron vom Stein, Prince von Hardenberg, von Scharnhorst, and Count Gneisenau. They set about reforming Prussia's administration, churches, finance and military.

Friedrich Wilhelm III. (* 3. August 1770 in Potsdam; † 7. Juni 1840 in Berlin) aus dem Haus Hohenzollern war seit 1797 König von Preußen und Kurfürst von Brandenburg.


Name.

The term derives from Old English ', ultimately from a Proto-Germanic root reconstructed as *"hlaþ"- or *"hlað-" ("to place"). It is also parallel and probably influenced by the Middle Dutch and Middle Low German ', used in identical senses as a load, cargo, or standardized unit.

Weight.

The Assize of Weights and Measures, one of the statutes of uncertain date from, defined the as 12 sacks' worth, equivalent to 24 weys, 336 London stone, or 4200 merchants' pounds (about 1835 kg). The last subsequently varied with the different values given to the sack of wool.  The flax and feather lasts were 1700 avoirdupois pounds (about 770 kg).  The English Ordnance Board defined the as 24 barrels of 100 avoirdupois pounds each (2,400 lbs. or about 1090 kg).  A Dutch last, or "Scheepslast", was Amsterdam "", which is. In the Dutch East India Company (, commonly abbreviated to VOC) the last was about in the 17th century, later becoming as much as. The last was also used as a measure of rice in Dutch Formosa. It was composed of 20 piculs and about equal to.

Quantity.

The Assize of Weights and Measures describes the as ten long thousands or 12,000 fish. The Norman French editions describe this as the "red herring" or and compose the herring last out of ten short thousands of twelve long hundreds, still making 12,000 fish altogether. (Elsewhere, the herring last was treated by volume.)  The comprised 20 dicker of 10 skins each (200 total) or, sometimes, 12 dozen skins (144 total).

Volume.

The English last could also be understood as the volume occupied by the other lasts. In some sources, the last is equated with. The beer last was 12 barrels, the cod last and some herring lasts were also 12 barrels, and the pitch last was 12 or 14 barrels.  The Polish last (') used for bulk trade in dry goods from the 16th to 19th century comprised 30 Polish bushels ('). In the early 19th century, this amounted to but varied over time and location.  The Dutch last, or "Scheepslast", has been equated to essentially of shipping space.

The last was a Dutch unit of mass, volume, and number, and a large English unit of weight, mass, volume, and number. It referred to standardized amounts of ships' lading and varied by commodity and over time.

Die Last war in der frühhansischen Zeit eine Maßeinheit und bezeichnete ursprünglich die Masse an Getreide, die von einem von vier Pferden gezogenen Fuhrwerk transportiert werden konnte. Im Mittelalter wird sie eine Messgröße, um die Transportkapazität von Schiffen zu bestimmen. Die „Last“ konnte regional und nach Warenart unterschiedlich sein, vereinfacht kann man sagen:


Occurrence and production.

Coal tar, which contains around 1.5% anthracene, remains a major source of this material. Common impurities are phenanthrene and carbazole. The mineral form of anthracene is called freitalite and is related to a coal deposit. A classic laboratory method for the preparation of anthracene is by cyclodehydration of o-methyl- or o-methylene-substituted diarylketones in the so-called Elbs reaction.

Reactions.

Reduction.

Reduction of anthracene with alkali metals yields the deeply colored radical anion salts M[anthracene] (M = Li, Na, K). Hydrogenation gives 9,10-dihydroanthracene, preserving the aromaticity of the two flanking rings.

Cycloadditions.

Anthracene photodimerizes by the action of UV light:  The dimer, called dianthracene (or sometimes paranthracene), is connected by a pair of new carbon-carbon bonds, the result of the [4+4] cycloaddition. It reverts to anthracene thermally or with UV irradiation below 300 nm. Substituted anthracene derivatives behave similarly. The reaction is affected by the presence of oxygen.  Anthracene also reacts with dienophile singlet oxygen in a [4+2]-cycloaddition (Diels–Alder reaction):

With electrophiles.

Chemical oxidation occurs readily, giving anthraquinone, CHO (below), for example using hydrogen peroxide and vanadyl acetylacetonate.  Electrophilic substitution of anthracene occurs at the 9 position. For example, formylation affords 9-anthracenecarboxaldehyde. Substitution at other positions is effected indirectly, for example starting with anthroquinone.

Uses.

Anthracene is converted mainly to anthraquinone, a precursor to dyes.

Niche.

Anthracene, a wide band-gap organic semiconductor is used as a scintillator for detectors of high energy photons, electrons and alpha particles. Plastics, such as polyvinyltoluene, can be doped with anthracene to produce a plastic scintillator that is approximately water-equivalent for use in radiation therapy dosimetry. Anthracene's emission spectrum peaks at between 400 nm and 440 nm.  It is also used in wood preservatives, insecticides, and coating materials.  Anthracene is commonly used as a UV tracer in conformal coatings applied to printed wiring boards. The anthracene tracer allows the conformal coating to be inspected under UV light. Anthracene also used in manufacturing of anthraquinone.

Derivatives.

A variety of anthracene derivatives find specialized uses. Derivatives having a hydroxyl group are 1-hydroxyanthracene and 2-hydroxyanthracene, homologous to phenol and naphthols, and hydroxyanthracene (also called anthrol, and anthracenol) are pharmacologically active. Anthracene may also be found with multiple hydroxyl groups, as in 9,10-dihydroxyanthracene.

Occurrence.

Anthracene, as many other polycyclic aromatic hydrocarbons, is generated during combustion processes. Exposure to humans happens mainly through tobacco smoke and ingestion of food contaminated with combustion products.

Toxicology.

Many investigations indicate that anthracene is noncarcinogenic: "consistently negative findings in numerous in vitro and in vivo genotoxicity tests". Early experiments suggested otherwise because crude samples were contaminated with other polycyclic aromatic compounds. Furthermore, it is readily biodegraded in soil. It is especially susceptible to degradation in the presence of light.

Anthracene is a solid polycyclic aromatic hydrocarbon (PAH) of formula CH, consisting of three fused benzene rings. It is a component of coal tar. Anthracene is used in the production of the red dye alizarin and other dyes. Anthracene is colorless but exhibits a blue (400–500 nm peak) fluorescence under ultraviolet radiation.

Anthracen [] (von griech. "anthrax", ‚Kohle‘), auch Paranaphthalin oder veraltet Anthrazen ist ein farbloser kristalliner Feststoff, der leicht sublimiert. Es ist ein polycyclischer aromatischer Kohlenwasserstoff und organischer Halbleiter mit der Summenformel CH, der aus drei anellierten Benzolringen aufgebaut ist.