Clarence and Carl Aguirre (born April 21, 2002) are former conjoined twins born in Silay City, Philippines. They were conjoined at the top of the head (vertical craniopagus). In 2003 they were brought to the United States by their mother Arlene in the hope of having them surgically separated. A revolutionary new process was used in separating the twin boys. Because "marathon" surgical operations have historically led to a high rate of mortality and morbidity, Clarence and Carl's doctors chose to separate them in several smaller operations, allowing the twins to recuperate after each surgery.

In October 2003, tissue expanders (pouches filled with saline) were implanted under the boys' scalps. This is common practice in separating conjoined twins, as it creates more skin that can be used to cover the twins' wounds after separation. Over the next ten months, the brothers underwent several more operations to tease apart their joined skulls and brains. On August 4, 2004, the final surgery was completed. All of these operations were performed at Montefiore Medical Center in the Bronx, New York by a team led by Dr. James T. Goodrich, a pediatric neurosurgeon and Dr. David A. Staffenberg, a plastic surgeon. They received most of their post-operative rehabilitation at Blythedale Children's Hospital in Valhalla, New York (Westchester County).

By December 2005, Clarence could walk short distances unassisted, and Carl could walk with a walker. As of August 2014 both boys and their mother live in a donated house in Scarsdale, New York. The twins continue to attend physical therapy at Blythedale. Goodrich says there was some degeneration of Carl’s right parietal lobe: he takes medication to control seizures, can utter just a word or two at a time, and has limited use of his left arm and leg. Both must still wear helmets to protect their brains; when they are fully grown, their skulls will be patched.

Athletes seeking to avoid testing positive use various methods. The most common methods include:

- Urine replacement, which involves replacing dirty urine with clean urine from someone who is not taking banned substances. Urine replacement can be done by catheterization or with a prosthetic penis such as The Original Whizzinator.

- Diuretics, used to cleanse the system before having to provide a sample.

- Blood transfusions, which increase the blood's oxygen carrying capacity, in turn increasing endurance without the presence of drugs that could trigger a positive test result.

Side effects in women include:

- hair loss

- male pattern baldness

- hypertrophy of the clitoris

- increased sex drive

- irregularities of the menstrual cycle

- development of masculine facial traits

- increased coarseness of the skin

- premature closure of the epiphysis

In countries where the use of these drugs is controlled, there is often a black market trade of smuggled or counterfeit drugs. The quality of these drugs may be poor and can cause health risks. In countries where anabolic steroids are strictly regulated, some have called for a regulatory relief. Steroids are available over-the-counter in some countries such as Thailand and Mexico.

The Hungerford massacre was a series of random shootings in Hungerford, England, United Kingdom, on 19 August 1987, when Michael Robert Ryan, an unemployed antique dealer and handyman, fatally shot 16 people, including a police officer, before taking his own life. The shootings, committed using a handgun and two semi-automatic rifles, occurred at several locations, including a school he had once attended. 15 other people were also shot but survived. No firm motive for the killings has ever been established, although one psychologist has theorised Ryan's motive for the massacre had been a form of "anger and contempt for the ordinary life" around him, which he himself was not a tangible part of.

A report was commissioned by Home Secretary Douglas Hurd. The Firearms (Amendment) Act 1988 was passed in the wake of the massacre, which bans the ownership of semi-automatic centre-fire rifles and restricts the use of shotguns with a capacity of more than three cartridges. The shootings remain one of the deadliest firearms incidents in British history.

Although often termed a "neurological condition," synesthesia is not listed in either the DSM-IV or the ICD since it most often does not interfere with normal daily functioning. Indeed, most synesthetes report that their experiences are neutral or even pleasant. Like perfect pitch, synesthesia is simply a difference in perceptual experience.

The simplest approach is test-retest reliability over long periods of time, using stimuli of color names, color chips, or a computer-screen color picker providing 16.7 million choices. Synesthetes consistently score around 90% on reliability of associations, even with years between tests. In contrast, non-synesthetes score just 30–40%, even with only a few weeks between tests and a warning that they would be retested.

Grapheme-color synesthetes, as a group, share significant preferences for the color of each letter (e.g. A tends to be red; O tends to be white or black; S tends to be yellow etc.) Nonetheless, there is a great variety in types of synesthesia, and within each type, individuals report differing triggers for their sensations and differing intensities of experiences. This variety means that defining synesthesia in an individual is difficult, and the majority of synesthetes are completely unaware that their experiences have a name.

Neurologist Richard Cytowic identifies the following diagnostic criteria for synesthesia in his "first" edition book. However, the criteria are different in the second book:

1. Synesthesia is involuntary and automatic.

2. Synesthetic perceptions are spatially extended, meaning they often have a sense of "location." For example, synesthetes speak of "looking at" or "going to" a particular place to attend to the experience.

3. Synesthetic percepts are consistent and generic (i.e. simple rather than pictorial).

4. Synesthesia is highly memorable.

5. Synesthesia is laden with affect.

Cytowic's early cases mainly included individuals whose synesthesia was frankly projected outside the body (e.g. on a "screen" in front of one's face). Later research showed that such stark externalization occurs in a minority of synesthetes. Refining this concept, Cytowic and Eagleman differentiated between "localizers" and "non-localizers" to distinguish those synesthetes whose perceptions have a definite sense of spatial quality from those whose perceptions do not.

Synesthesia is found in at least 4.4% of the population, as a high estimate, which is equivalent to 1 in 23 people. This study had also concluded that one common form of synesthesia—grapheme-color synesthesia (colored letters and numbers) – is found in more than one percent of the population, and this latter prevalence of graphemes-color synesthesia has now been independently verified in a yet larger sample. Earlier estimates of the prevalence of synesthesia were based on "best-guess" estimations only ("e.g." 1 in 250,000) or had limitations in their methodologies because they required synesthetes to refer themselves for study ("e.g." 1 in 2000) and for this reason the authors of those studies had been moderate in their claims. Also, some individuals will not self-classify as synesthetes because they do not realize that their perceptions are different from those of everyone else.

The most common forms of synesthesia are those that trigger colors, and the most prevalent of all is day-color. Also relatively common is grapheme-color synesthesia. We can think of "prevalence" both in terms of how common is synesthesia (or different forms of synesthesia) within the population, or how common are different forms of synesthesia within synesthetes. So within synesthetes, forms of synesthesia that trigger color also appear to be the most common forms of synesthesia with a prevalence rate of 86% within synesthetes. In another study, music-color is also prevalent at 18–41%. Some of the rarest are reported to be auditory-tactile, mirror-touch, and lexical-gustatory.

There is research to suggest that the likelihood of having synesthesia is greater in people with autism.

Islamophobia in Norway refers to the set of discourses, behaviours and structures which express feelings of anxiety, fear, hostility and rejection towards Islam and/or Muslims in Norway. Islamophobia can manifest itself through discrimination in the workforce, negative coverage in the media, and violence against Muslims.

Afro-textured hair is the natural hair texture of certain populations in Africa, the African diaspora, Australia and Asia, which has not been altered by hot combs, flat irons or chemicals (through perming, relaxation or other straightening methods). Each strand of this hair type grows in a tiny, spring-like helix shape. The overall effect is such that, compared to straight, wavy or curly hair, afro-textured hair appears denser.

The Control of Vibration at Work Regulations 2005, created under the Health and Safety at Work etc. Act 1974. is the legislation in the UK that governs exposure to vibration and assists with preventing HAVS occurring.

Good practice in industrial health and safety management requires that worker vibration exposure is assessed in terms of acceleration amplitude and duration. Using a tool that vibrates slightly for a long time can be as damaging as using a heavily vibrating tool for a short time. The duration of use of the tool is measured as trigger time, the period when the worker actually has their finger on the trigger to make the tool run, and is typically quoted in hours per day. Vibration amplitude is quoted in metres per second squared, and is measured by an accelerometer on the tool or given by the manufacturer. Amplitudes can vary significantly with tool design, condition and style of use, even for the same type of tool.

In the UK, Health and Safety Executive gives the example of a hammer drill which can vary from 6m/s² to 25m/s². HSE publishes a list of typically observed vibration levels for various tools, and graphs of how long each day a worker can be exposed to particular vibration levels. This makes managing the risk relatively straightforward. Tools are given an Exposure Action Value (EAV, the time which a tool can be used before action needs to be taken to reduce vibration exposure) and an Exposure Limit Value (ELV, the time after which a tool may not be used).

In the United States, the National Institute for Occupational Safety and Health published a similar database where values for sound power and vibrations for commonly found tools from large commercial vendors in the United States were surveyed. Further testing is underway for more and newer tools.

The effect of legislation in various countries on worker vibration limits has been to oblige equipment providers to develop better-designed, better-maintained tools, and for employers to train workers appropriately. It also drives tool designers to innovate to reduce vibration. Some examples are the easily manipulated mechanical arm (EMMA) and the suspension mechanism designed into chainsaws.

Cryptomnesia occurs when a forgotten memory returns without it being recognized as such by the subject, who believes it is something new and original. It is a memory bias whereby a person may falsely recall generating a thought, an idea, a tune, or a joke, not deliberately engaging in plagiarism but rather experiencing a memory as if it were a new inspiration.

Islamophobia in the United States can be described as the unvalidated, highly speculative, affective distrust and hostility towards Muslims, Islam, and those perceived as following the religion and or appear as members of the religion and its associative groups. This social aversion and bias is facilitated and perpetuated by violent and uncivilized stereotypes portrayed in various forms of American media networks and political platforms that result in the marginalization, discrimination, and exclusion of the Muslims and Muslim perceived individuals. Media and politicians capitalize on public fear and distrust of Muslims through laws that specifically target Muslims, while the media emphasizes Muslim religious extremism in association with violent activity.

Advocacy groups like Center for American Progress explain that this social phenomenon is not new, but rather, has increased it’s presence in American social and political discourse over the past ten to fifteen years. They cite that several organizations donate large amounts of money to create the “Islamophobia megaphone”. CAP defines the megaphone analogy as “a tight network of anti- Muslim, anti- Islam foundations, misinformation experts, validators, grass root organizations, religious rights groups and their allies in the media and in politics” who work together to misrepresent Islam and Muslims in the United States. As a result of this network, Islam is now one of the most stigmatized religions, with only 37 percent of Americans having a favorable opinion of Islam, according to a 2010 ABC News/ Washington Post poll. This biased perception of Islam and Muslims manifests itself into the discrimination of racially perceived Muslims in the law and media, and is conceptually reinforced by the Islamophobia Network.

Anti vibration gloves are traditionally made with a thick and soft palm material to insulate from the vibrations. The protection is highly dependent on frequency range, most gloves provide no protection in palm and wrist below ~50Hz and in fingers below ~400Hz. Factors such as high grip force, cold hands or vibration forces in shear direction can have a reducing effect and or increase damage to the hands and arms. Gloves do help to keep hands warm but to get the desired effect, the frequency output from the tool must match the properties of the vibration glove that is selected. It should be noted that Anti Vibration gloves in many cases amplify the vibrations at frequencies lower than those mentioned in the text above.

In many post-Columbian, Western societies, adjectives such as "wooly", "kinky", "nappy", or "spiralled" have frequently been used to describe natural afro-textured hair. More recently, however, it has become common in some circles to apply numerical grading systems to human hair types.

One popular version of these systems classifies afro-textured hair as 'type 4' (straight hair is type 1, wavy type 2, and curly is type 3, with the letters A, B, and C used to indicate the degree of coil variation within each type), with the subcategory of type 4C being most exemplary of this hair type (Walker, 1997). However, afro-textured hair is often difficult to categorize because of the many different variations among individuals. Those variations include pattern (mainly tight coils), pattern size (watch spring to chalk), density (sparse to dense), strand diameter (fine, medium, coarse), and feel (cottony, wooly, spongy).

The chart below is the most commonly used chart to help determine hair types:

Several different approaches for classifying leprosy exist, but parallels exist.

- The World Health Organization system distinguishes "paucibacillary" and "multibacillary" based upon the proliferation of bacteria.("-" refers to a low quantity.)

- The SHAY scale provides five gradations.

- The ICD-10, though developed by the WHO, uses Ridley-Jopling and not the WHO system. It also adds an indeterminate ("I") entry.

- In MeSH, three groupings are used.

A difference in immune response to the tuberculoid and lepromatous forms is seen.

Leprosy may also be divided into:

This disease may also occur with only neural involvement, without skin lesions.

According to the World Health Organization, diagnosis in areas where people are frequently infected is based on one of these main signs:

- Skin lesion consistent with leprosy and with definite sensory loss

- Positive skin smears

Skin lesions can be single or multiple, and usually hypopigmented, although occasionally reddish or copper-colored. The lesions may be macules (flat), papules (raised), or nodular. The sensory loss at the skin lesion is important because this feature can help differentiate it from other causes of skin lesions such as tinea versicolor. Thickened nerves are associated with leprosy and can be accompanied by loss of sensation or muscle weakness. However, without the characteristic skin lesion and sensory loss, muscle weakness is not considered a reliable sign of leprosy.

In some cases, acid-fast leprosy bacilli in skin smears are considered diagnostic; however, the diagnosis is clinical.

Diagnosis in areas where the disease is uncommon, such as the United States, is often delayed because healthcare providers are unaware of leprosy and its symptoms. Early diagnosis and treatment prevent nerve involvement, the hallmark of leprosy, and the disability it causes.

Many kinds of leprosy are known, but some symptoms are common to them, including runny nose, dry scalp, eye problems, skin lesions, muscle weakness, reddish skin, smooth, shiny, diffuse thickening of facial skin, ear, and hand, loss of sensation in fingers and toes, thickening of peripheral nerves, and flat nose due to destruction of nasal cartilage. Also, phonation and resonation of sound occur during speech. Often, atrophy of the testes with resulting impotence occurs.

Boanthropy is a psychological disorder in which a human believes himself or herself to be a bovine.

Don Juanism or Don Juan syndrome is a non-clinical term for the desire, in a man, to have sex with many different female partners.

The name derives from the Don Juan of opera and fiction. The term satyriasis is sometimes used as a synonym for Don Juanism. The term has also been referred to as the male equivalent of nymphomania in women. These terms no longer apply with any accuracy as psychological or legal categories of psychological disorder.

Focal infection theory is the historical concept that many chronic diseases, including systemic and common ones, are caused by focal infections. In present medical consensus, a focal infection is a localized infection, often asymptomatic, that causes disease elsewhere in the host, but focal infections are fairly infrequent and limited to fairly uncommon diseases. (Distant injury is focal infection's key principle, whereas in ordinary infectious disease, the infection itself is systemic, as in measles, or the initially infected site is readily identifiable and invasion progresses contiguously, as in gangrene.) Focal infection theory, rather, so explained virtually all diseases, including arthritis, atherosclerosis, cancer, and mental illnesses.

An ancient concept that took modern form around 1900, focal infection theory was widely accepted in medicine by the 1920s. In the theory, the "focus of infection" might lead to secondary infections at sites particularly susceptible to such microbial species or toxin. Commonly alleged foci were diverse—appendix, urinary bladder, gall bladder, kidney, liver, prostate, and nasal sinuses—but most commonly were oral. Besides dental decay and infected tonsils, both dental restorations and especially endodontically treated teeth were blamed as foci. The putative "oral sepsis" was countered by tonsillectomies and tooth extractions, including of endodontically treated teeth and even of apparently healthy teeth, newly popular approaches—sometimes leaving individuals toothless—to treat or prevent diverse diseases.

Drawing severe criticism in the 1930s, focal infection theory—whose popularity zealously exceeded consensus evidence—was discredited in the 1940s by research attacks that drew overwhelming consensus of this sweeping theory's falsity. Thereupon, dental restorations and endodontic therapy became again favored. Untreated endodontic "disease" retained mainstream recognition as fostering systemic disease. But only alternative medicine and later biological dentistry continued highlighting sites of dental treatment—still endodontic therapy, but, more recently, also dental implant, and even tooth extraction, too—as foci of infection causing chronic and systemic diseases. In mainstream dentistry and medicine, the primary recognition of focal infection is endocarditis, if oral bacteria enter blood and infect the heart, perhaps its valves.

Entering the 21st century, scientific evidence supporting general relevance of focal infections remained slim, yet evolved understandings of disease mechanisms had established a third possible mechanism—altogether, metastasis of infection, metastatic toxic injury, and, as recently revealed, metastatic immunologic injury—that might occur simultaneously and even interact. Meanwhile, focal infection theory has gained renewed attention, as dental infections apparently are widespread and significant contributors to systemic diseases, although mainstream attention is on ordinary periodontal disease, not on hypotheses of stealth infections via dental "treatment". Despite some doubts renewed in the 1990s by conventional dentistry's critics, dentistry scholars maintain that endodontic therapy can be performed without creating focal infections.

In psychiatry, derailment (also loosening of association, asyndesis, asyndetic thinking, knight's move thinking, or entgleisen) is a thought disorder characterized by discourse consisting of a sequence of unrelated or only remotely related ideas. The frame of reference often changes from one sentence to the next.

In a mild manifestation, this thought disorder is characterized by slippage of ideas further and further from the point of a discussion. Derailment can often be manifestly caused by intense emotions such as euphoria or hysteria. Some of the synonyms given above ("loosening of association", "asyndetic thinking") are used by some authors to refer just to a "loss of goal": discourse that sets off on a particular idea, wanders off and never returns to it. A related term is tangentiality—it refers to off-the-point, oblique or irrelevant answers given to questions. In some studies on creativity, "knight's move thinking", while it describes a similarly loose association of ideas, is not considered a mental disorder or the hallmark of one; it is sometimes used as a synonym for lateral thinking.

The first documented instance of cryptomnesia occurred in 1874 with the medium Stainton Moses.

The word was first used by the psychiatrist Théodore Flournoy, in reference to the case of medium Hélène Smith (Catherine-Élise Müller) to suggest the high incidence in psychism of "latent memories on the part of the medium that come out, sometimes greatly disfigured by a subliminal work of imagination or reasoning, as so often happens in our ordinary dreams."

Carl Gustav Jung treated the subject in his thesis "On the Psychology and Pathology of So-Called Occult Phenomena" (1902) and in an article, "Cryptomnesia" (1905), suggested the phenomenon in Friedrich Nietzsche's "Thus Spoke Zarathustra". The idea was studied or mentioned by Géza Dukes, Sándor Ferenczi and Wilhelm Stekel as well as by Sigmund Freud in speaking of the originality of his inventions.

The most famous sufferer of this disorder is claimed to be Nebuchadnezzar II, who in the Book of Daniel "was driven from men, and did eat grass as oxen". Most probably, the authors were making fun of his aversion to meat or violence.

Carl Jung would subsequently instance 'Nebuchadnezzar...[as] a complete regressive degeneration of a man who has overreached himself'.

According to Persian traditions, the Buyid prince Majd al-Dawla was suffering from an illusion that he is a cow, making the sound of a cow and asking that to be killed so that his flesh could be consumed. He was cured by Avicenna.

With the 1950s introduction of antibiotics, attempts to explain unexplained diseases via bacterial etiology seemed all the more unlikely. By the 1970s, however, it was established that antibiotics could trigger bacteria's switch to their L phase. Eluding detection by traditional methods of medical microbiology, bacterial L forms and the similar mycoplasma—and, later, viruses—became the entities expected in the theory of focal infection. Yet until the 1980s, such researchers were scarce, largely via scarce funding for such investigations.

Despite the limited funding, research established that L forms can adhere to red blood cells and thereby disseminate from foci within internal organs such as the spleen, or from oral tissues and the intestines, especially during dysbiosis. Perhaps some of Weston Price's identified "toxins" in endodontically treated teeth were L forms, thought nonexistent by bacteriologists of his time and widely overlooked into the 21st century. Apparently, dental infections, including by uncultured or cryptic microorganisms, contribute to systemic diseases.

The diagnosis of AOS is a clinical diagnosis based on the specific features described above. A system of major and minor criteria was proposed.

The combination of two major criteria would be sufficient for the diagnosis of AOS, while a combination of one major and one minor feature would be suggestive of AOS. Genetic testing can be performed to test for the presence of mutation in one of the known genes, but these so far only account for an estimated 50% of patients with AOS. A definitive diagnosis may therefore not be achieved in all cases.

Diagnosis is very difficult, and usually one of exclusion. SMA syndrome is thus considered only after patients have undergone an extensive evaluation of their gastrointestinal tract including upper endoscopy, and evaluation for various malabsorptive, ulcerative and inflammatory instestinal conditions with a higher diagnostic frequency. Diagnosis may follow x-ray examination revealing duodenal dilation followed by abrupt constriction proximal to the overlying SMA, as well as a delay in transit of four to six hours through the gastroduodenal region. Standard diagnostic exams include abdominal and pelvic computed tomography (CT) scan with oral and IV contrast, upper gastrointestinal series (UGI), and, for equivocal cases, hypotonic duodenography. In addition, vascular imaging studies such as ultrasound and contrast angiography may be used to indicate increased bloodflow velocity through the SMA or a narrowed SMA angle.

Despite multiple case reports, there has been controversy surrounding the diagnosis and even the existence of SMA syndrome since symptoms do not always correlate well with radiologic findings, and may not always improve following surgical correction. However, the reason for the persistence of gastrointestinal symptoms even after surgical correction in some cases has been traced to the remaining prominence of reversed peristalsis in contrast to direct peristalsis.

Since females between the ages of 10 and 30 are most frequently afflicted, it is not uncommon for physicians to initially and incorrectly assume that emaciation is a choice of the patient instead of a consequence of SMA syndrome. Patients in the earlier stages of SMA syndrome often remain unaware that they are ill until substantial damage to their health is done, since they may attempt to adapt to the condition by gradually decreasing their food intake or naturally gravitating toward a lighter and more digestible diet.

OSD occurs from the combined effects of tibial tuberosity immaturity and quadriceps tightness. There is a possibility of migration of the ossicle or fragmentation in Osgood-Schlatter patients. The implications of OSD and the ossification of the tubercle can lead to functional limitations and pain for patients into adulthood.

Of people admitted with OSD, about half were children who were between the ages of 1 and 17. In addition, in 2014, a case study of 261 patients was observed over 12 to 24 months. 237 of these people responded well to sport restriction and non-steroid anti-inflammatory agents, which resulted in recovery to normal athletic activity.