text:
National Institutes of Health

The National Institutes of Health, commonly referred to as NIH, is the primary agency of the United States government responsible for biomedical and public health research. It was founded in the late 1880s and is now part of the United States Department of Health and Human Services. Many NIH facilities are located in Bethesda, Maryland, and other nearby suburbs of the Washington metropolitan area, with other primary facilities in the Research Triangle Park in North Carolina and smaller satellite facilities located around the United States. The NIH conducts its own scientific research through the NIH Intramural Research Program (IRP) and provides major biomedical research funding to non-NIH research facilities through its Extramural Research Program.

, the IRP had 1,200 principal investigators and more than 4,000 postdoctoral fellows in basic, translational, and clinical research, being the largest biomedical research institution in the world, while, as of 2003, the extramural arm provided 28% of biomedical research funding spent annually in the U.S., or about US$26.4 billion.

The NIH comprises 27 separate institutes and centers of different biomedical disciplines and is responsible for many scientific accomplishments, including the discovery of fluoride to prevent tooth decay, the use of lithium to manage bipolar disorder, and the creation of vaccines against hepatitis, Haemophilus influenzae (HIB), and human papillomavirus (HPV).

In 2019, the NIH was ranked number two in the world, behind Harvard University, for biomedical sciences in the Nature Index, which measured the largest contributors to papers published in a subset of leading journals from 2015 to 2018. NIH supports Diversity, equity, and inclusion.

Origins

In 1887, a laboratory for the study of bacteria, the Hygienic Laboratory, was established within the Marine Hospital Service, which at the time was expanding its functions beyond the system of Marine Hospitals into quarantine and research programs. It was initially located at the New York Marine Hospital on Staten Island. In 1891, it moved to the top floor of the Butler Building in Washington, D.C. In 1904, it moved again to a new campus at the Old Naval Observatory, which grew to include five major buildings.

In 1901, the Division of Scientific Research was formed, which included the Hygienic Laboratory as well as other research offices of the Marine Hospital Service. In 1912, the Marine Hospital Service became the Public Health Service (PHS). In 1922, PHS established a Special Cancer Investigations laboratory at Harvard Medical School. This marked the beginning of a partnership with universities.

In 1930, the Hygienic Laboratory was re-designated as the National Institute of Health by the Ransdell Act, and was given $750,000 to construct two NIH buildings at the Old Naval Observatory campus. In 1937, NIH absorbed the rest of the Division of Scientific Research, of which it was formerly part.

In 1938, NIH moved to its current campus in Bethesda, Maryland. Over the next few decades, Congress would markedly increase funding of the NIH, and various institutes and centers within the NIH were created for specific research programs. In 1944, the Public Health Service Act was approved, and the National Cancer Institute became a division of NIH. In 1948, the name changed from National Institute of Health to National Institutes of Health.

Later history
In the 1960s, virologist and cancer researcher Chester M. Southam injected HeLa cancer cells into patients at the Jewish Chronic Disease Hospital. When three doctors resigned after refusing to inject patients without their consent, the experiment gained considerable media attention. The NIH was a major source of funding for Southam's research and had required all research involving human subjects to obtain their consent prior to any experimentation. Upon investigating all of their grantee institutions, the NIH discovered that the majority of them did not protect the rights of human subjects. From then on, the NIH has required all grantee institutions to approve any research proposals involving human experimentation with review boards.

In 1967, the Division of Regional Medical Programs was created to administer grants for research for heart disease, cancer, and strokes. That same year, the NIH director lobbied the White House for increased federal funding in order to increase research and the speed with which health benefits could be brought to the people. An advisory committee was formed to oversee the further development of the NIH and its research programs. By 1971 cancer research was in full force and President Nixon signed the National Cancer Act, initiating a National Cancer Program, President's Cancer Panel, National Cancer Advisory Board, and 15 new research, training, and demonstration centers.

Funding for the NIH has often been a source of contention in Congress, serving as a proxy for the political currents of the time. In 1992, the NIH encompassed nearly 1 percent of the federal government's operating budget and controlled more than 50 percent of all funding for health research, and 85 percent of all funding for health studies in universities. While government funding for research in other disciplines has been increasing at a rate similar to inflation since the 1970s, research funding for the NIH nearly tripled through the 1990s and early 2000s, but has remained relatively stagnant since then.

By the 1990s, the NIH committee focus had shifted to DNA research and launched the Human Genome Project.

Leadership
The NIH Office of the Director is the central office responsible for setting policy for NIH, and for planning, managing, and coordinating the programs and activities of all NIH components. The NIH Director plays an active role in shaping the agency's activities and outlook. The Director is responsible for providing leadership to the Institutes and Centers by identifying needs and opportunities, especially in efforts involving multiple Institutes. Within the Director's Office is the Division of Program Coordination, Planning and Strategic Initiatives with 12 divisions including:
 * Office of AIDS Research
 * Office of Research on Women's Health
 * Office of Disease Prevention
 * Sexual and Gender Minority Research Office
 * Tribal Health Research Office
 * Office of Program Evaluation and Performance

The Agency Intramural Research Integrity Officer "is directly responsible for overseeing the resolution of all research misconduct allegations involving intramural research, and for promoting research integrity within the NIH Office of Intramural Research (OIR)." There is a Division of Extramural Activities, which has its own Director. The Office of Ethics has its own Director, as does the Office of Global Research.

Locations and campuses
Intramural research is primarily conducted at the main campus in Bethesda, Maryland, and Rockville, Maryland, and the surrounding communities.

The Bayview Campus in Baltimore, Maryland houses the research programs of the National Institute on Aging, National Institute on Drug Abuse, and National Human Genome Research Institute with nearly 1,000 scientists and support staff. The Frederick National Laboratory in Frederick, MD and the nearby Riverside Research Park, houses many components of the National Cancer Institute, including the Center for Cancer Research, Office of Scientific Operations, Management Operations Support Branch, the division of Cancer Epidemiology and Genetics and the division of Cancer Treatment and Diagnosis.

The National Institute of Environmental Health Sciences is located in the Research Triangle region of North Carolina.

Other ICs have satellite locations in addition to operations at the main campus. The National Institute of Allergy and Infectious Diseases maintains its Rocky Mountain Labs in Hamilton, Montana, with an emphasis on BSL3 and BSL4 laboratory work. NIDDK operates the Phoenix Epidemiology and Clinical Research Branch in Phoenix, Arizona.

Research

As of 2017, 153 scientists receiving financial support from the NIH have been awarded a Nobel Prize and 195 have been awarded a Lasker Award.

Intramural and extramural research
NIH devotes 10% of its funding to research within its own facilities (intramural research), and gives >80% of its funding in research grants to extramural (outside) researchers. Of this extramural funding, a certain percentage (2.8% in 2014) must be granted to small businesses under the SBIR/STTR program. , the extramural funding consisted of about 50,000 grants to more than 325,000 researchers at more than 3000 institutions. , this rate of granting remained reasonably steady, at 47,000 grants to 2,700 organizations. , NIH spent US$10.7bn (not including temporary funding from the American Recovery and Reinvestment Act of 2009) on clinical research, US$7.4bn on genetics-related research, US$6.0bn on prevention research, US$5.8bn on cancer, and US$5.7bn on biotechnology.

Public Access Policy
In 2008 a Congressional mandate called for investigators funded by the NIH to submit an electronic version of their final manuscripts to the National Library of Medicine's research repository, PubMed Central (PMC), no later than 12 months after the official date of publication. The NIH Public Access Policy was the first public access mandate for a U.S. public funding agency.

Economic return
In 2000, the Joint Economic Committee of Congress reported NIH research, which was funded at $16 billion a year in 2000, that some econometric studies had given a rate of return of 25 to 40 percent per year by reducing the economic cost of illness in the US. It found that of the 21 drugs with the highest therapeutic impact on society introduced between 1965 and 1992, public funding was "instrumental" for 15. As of 2011 NIH-supported research helped to discover 153 new FDA-approved drugs, vaccines, and new indications for drugs in the 40 years prior. One study found NIH funding aided either directly or indirectly in developing the drugs or drug targets for all of the 210 FDA-approved drugs from 2010 to 2016. In 2015, Pierre Azoulay et al. estimated $10 million invested in research generated two to three new patents.

Notable discoveries and developments
Since its inception, the NIH intramural research program has been a source of many pivotal scientific and medical discoveries. Some of these include:
 * 1908: George W. McCoy's discovery that rodents were a reservoir of bubonic plague.
 * 1911: George W. McCoy, Charles W. Chapin, William B. Wherry, and B. H. Lamb described the previously unknown tularemia.
 * 1924: Roscoe R. Spencer and Ralph R. Parker developed a vaccine against Rocky Mountain spotted fever.
 * 1930: Sanford M. Rosenthal developed a treatment for mercury poisoning used widely before the development of dimercaptoethanol.
 * 1943: Wilton R. Earle pioneered the cell culture process and published a paper describing the production of malignancy in vitro, Katherine K. Sanford developed the first clone from an isolated cancer cell, and Virginia J. Evans devised a medium that supported growth of cells in vitro.
 * 1940s–1950s: Bernard Horecker and colleagues described the pentose phosphate pathway.
 * 1950s: Julius Axelrod discovered a new class of enzymes, cytochrome P450 monooxygenases, a fundamental of drug metabolism.
 * 1950: Earl Stadtman discovered phosphotransacetylose, elucidating the role of acetyl CoA in fatty acid metabolism.
 * 1960s: Discovered the first human slow virus disease, kuru, which is a degenerative, fatal infection of the central nervous system. This discovery of a new mechanism for infectious diseases revolutionized thinking in microbiology and neurology.
 * 1960s: Defined the mechanisms that regulate noradrenaline, one of the most important neurotransmitters in the brain.
 * 1960s: Developed the first licensed rubella vaccine and the first test for rubella antibodies for large scale testing.
 * 1960s: Developed an effective combination drug regimen for Hodgkin's lymphoma.
 * 1960s: Discovery that tooth decay is caused by bacteria.
 * 1970s: Developed the assay for human chorionic gonadotropin that evolved into the home pregnancy tests.
 * 1970s: Described the hormonal cycle involved in menstruation.
 * 1980s: Determined the complete structure of the IgE receptor that is involved in allergic reactions.
 * 1990s: Hari Reddi's identification and purification of bone morphogenetic proteins
 * 1990s: First trial of gene therapy in humans.

NIH Toolbox
In September 2006, the NIH Blueprint for Neuroscience Research started a contract for the NIH Toolbox for the Assessment of Neurological and Behavioral Function to develop a set of state-of-the-art measurement tools to enhance collection of data in large cohort studies. Scientists from more than 100 institutions nationwide contributed. In September 2012, the NIH Toolbox was rolled out to the research community. NIH Toolbox assessments are based, where possible, on Item Response Theory and adapted for testing by computer.

Database of Genotypes and Phenotypes
NIH sponsors the Database of Genotypes and Phenotypes (dbGaP), a repository of information produced by studies investigating the interaction of genotype and phenotype. The information includes phenotypes, molecular assay data, analyses and documents. Summary-level data is available to the general public whereas the individual-level data is accessible to researchers. According to the City Journal NIH denies access to such attributes as intelligence, education and health on the grounds that studying their genetic basis would be stigmatizing.

Coronavirus vaccine
The NIH partnered with Moderna in 2020 during the COVID-19 pandemic to develop a vaccine. The final phase of testing began on July 27 with up to 30,000 volunteers assigned to one of two groups—one receiving the mRNA-1273 vaccine and the other receiving salt water injections—and continued until there had been approximately 100 cases of COVID-19 among the participants. In 2021, the NIH contributed $4,395,399 towards the Accelerating COVID-19 Therapeutic Interventions and Vaccines (ACTIV) program.

Collaboration with Wuhan Institute of Virology
Following the outbreak of the COVID-19 pandemic, NIH-funded EcoHealth Alliance has been the subject of controversy and increased scrutiny due to its ties to the Wuhan Institute of Virology (WIV)—which has been at the center of speculation since early 2020 that SARS-CoV-2 may have escaped in a lab incident. Under political pressure, the NIH withdrew funding to EcoHealth Alliance in July 2020.

NIH Interagency Pain Research Coordinating Committee
On February 13, 2012, the National Institutes of Health (NIH) announced a new group of individuals assigned to research pain. This committee is composed of researchers from different organizations and will focus to "coordinate pain research activities across the federal government with the goals of stimulating pain research collaboration… and providing an important avenue for public involvement" ("Members of new", 2012). With a committee such as this research will not be conducted by each individual organization or person but instead a collaborating group which will increase the information available. With this hopefully more pain management will be available including techniques for those with arthritis. In 2020 Beth Darnall, American scientist and pain psychologist, was appointed as scientific member of the group.

Budget and politics
To allocate funds, the NIH must first obtain its budget from Congress. This process begins with institute and center (IC) leaders collaborating with scientists to determine the most important and promising research areas within their fields. IC leaders discuss research areas with NIH management who then develops a budget request for continuing projects, new research proposals, and new initiatives from the Director. NIH submits its budget request to the Department of Health and Human Services (HHS), and the HHS considers this request as a portion of its budget. Many adjustments and appeals occur between NIH and HHS before the agency submits NIH's budget request to the Office of Management and Budget (OMB). OMB determines what amounts and research areas are approved for incorporation into the President's final budget. The President then sends NIH's budget request to Congress in February for the next fiscal year's allocations. The House and Senate Appropriations Subcommittees deliberate and by fall, Congress usually appropriates funding. This process takes approximately 18 months before the NIH can allocate any actual funds.

When a government shutdown occurs, the NIH continues to treat people who are already enrolled in clinical trials, but does not start any new clinical trials and does not admit new patients who are not already enrolled in a clinical trial, except for the most critically ill, as determined by the NIH Director.

Historical funding
Over the last century, the responsibility to allocate funding has shifted from the OD and Advisory Committee to the individual ICs and Congress increasingly set apart funding for particular causes. In the 1970s, Congress began to earmark funds specifically for cancer research, and in the 1980s there was a significant amount allocated for AIDS/HIV research.

Funding for the NIH has often been a source of contention in Congress, serving as a proxy for the political currents of the time. During the 1980s, President Reagan repeatedly tried to cut funding for research, only to see Congress partly restore funding. The political contention over NIH funding slowed the nation's response to the AIDS epidemic; while AIDS was reported in newspaper articles from 1981, no funding was provided for research on the disease. In 1984 National Cancer Institute scientists found implications that "variants of a human cancer virus called HTLV-III are the primary cause of acquired immunodeficiency syndrome (AIDS)," a new epidemic that gripped the nation.

In 1992, the NIH encompassed nearly 1 percent of the federal government's operating budget and controlled more than 50 percent of all funding for health research and 85 percent of all funding for health studies in universities. From 1993 to 2001 the NIH budget doubled. For a time, funding essentially remained flat, and for seven years following the financial crisis, the NIH budget struggled to keep up with inflation.

In 1999 Congress increased the NIH's budget by $2.3 billion to $17.2 billion in 2000. In 2009 Congress again increased the NIH budget to $31 billion in 2010. In 2017 and 2018, Congress passed laws with bipartisan support that substantially increasing appropriations for NIH, which was 37.3 billion dollars annually in FY2018.

Extramural research
Researchers at universities or other institutions outside of NIH can apply for research project grants (RPGs) from the NIH. There are numerous funding mechanisms for different project types (e.g., basic research, clinical research, etc.) and career stages (e.g., early career, postdoc fellowships, etc.). The NIH regularly issues "requests for applications" (RFAs), e.g., on specific programmatic priorities or timely medical problems (such as Zika virus research in early 2016). In addition, researchers can apply for "investigator-initiated grants" whose subject is determined by the scientist.

The total number of applicants has increased substantially, from about 60,000 investigators who had applied during the period from 1999 to 2003 to slightly less than 90,000 in who had applied during the period from 2011 to 2015. Due to this, the "cumulative investigator rate", that is, the likelihood that unique investigators are funded over a 5-year window, has declined from 43% to 31%.

R01 grants are the most common funding mechanism and include investigator-initiated projects. The roughly 27,000 to 29,000 R01 applications had a funding success of 17-19% during 2012 though 2014. Similarly, the 13,000 to 14,000 R21 applications had a funding success of 13-14% during the same period. In FY 2016, the total number of grant applications received by the NIH was 54,220, with approximately 19% being awarded funding. Institutes have varying funding rates. The National Cancer Institute awarded funding to 12% of applicants, while the National Institute for General Medical Science awarded funding to 30% of applicants.

Funding criteria
NIH employs five broad decision criteria in its funding policy. First, ensure the highest quality of scientific research by employing an arduous peer review process. Second, seize opportunities that have the greatest potential to yield new knowledge and that will lead to better prevention and treatment of disease. Third, maintain a diverse research portfolio in order to capitalize on major discoveries in a variety of fields such as cell biology, genetics, physics, engineering, and computer science. Fourth, address public health needs according to the disease burden (e.g., prevalence and mortality). And fifth, construct and support the scientific infrastructure (e.g., well-equipped laboratories and safe research facilities) necessary to conduct research.

Advisory committee members advise the institute on policy and procedures affecting the external research programs and provide a second level of review for all grant and cooperative agreement applications considered by the Institute for funding.

Gender and sex bias
In 2014, it was announced that the NIH is directing scientists to perform their experiments with both female and male animals, or cells derived from females as well as males if they are studying cell cultures, and that the NIH would take the balance of each study design into consideration when awarding grants. The announcement also stated that this rule would probably not apply when studying sex-specific diseases (for example, ovarian or testicular cancer).

General public
One of the goals of the NIH is to "expand the base in medical and associated sciences in order to ensure a continued high return on the public investment in research." Taxpayer dollars funding NIH are from the taxpayers, making them the primary beneficiaries of advances in research. Thus, the general public is a key stakeholder in the decisions resulting from the NIH funding policy. However, some in the general public do not feel their interests are being represented, and individuals have formed patient advocacy groups to represent their own interests.

Extramural researchers and scientists
Important stakeholders of the NIH funding policy include researchers and scientists. Extramural researchers differ from intramural researchers in that they are not employed by the NIH but may apply for funding. Throughout the history of the NIH, the amount of funding received has increased, but the proportion to each IC remains relatively constant. The individual ICs then decide who will receive the grant money and how much will be allotted.

Policy changes on who receives funding significantly affect researchers. For example, the NIH has recently attempted to approve more first-time NIH R01 applicants or the research grant applications of young scientists. To encourage the participation of young scientists, the application process has been shortened and made easier. In addition, first-time applicants are being offered more funding for their research grants than those who have received grants in the past.

Commercial partnerships
In 2011 and 2012, the Department of Health and Human Services Office of Inspector General published a series of audit reports revealing that throughout the fiscal years 2000–2010, institutes under the aegis of the NIH did not comply with the time and amount requirements specified in appropriations statutes, in awarding federal contracts to commercial partners, committing the federal government to tens of millions of dollars of expenditure ahead of appropriation of funds from Congress.

Institutes and centers
The NIH is composed of 27 separate institutes and centers that conduct and coordinate biomedical research. These are:

 * National Cancer Institute (NCI)
 * National Eye Institute (NEI)
 * National Heart, Lung, and Blood Institute (NHLBI)
 * National Human Genome Research Institute (NHGRI)
 * National Institute on Aging (NIA)
 * National Institute on Alcohol Abuse and Alcoholism (NIAAA)
 * National Institute of Allergy and Infectious Diseases (NIAID)
 * National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS)
 * National Institute of Biomedical Imaging and Bioengineering (NIBIB)
 * National Institute of Child Health and Human Development (NICHD)
 * National Institute on Deafness and Other Communication Disorders (NIDCD)
 * National Institute of Dental and Craniofacial Research (NIDCR)
 * National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
 * National Institute on Drug Abuse (NIDA)
 * National Institute of Environmental Health Sciences (NIEHS)
 * National Institute of General Medical Sciences (NIGMS)
 * National Institute of Mental Health (NIMH)
 * National Institute on Minority Health and Health Disparities (NIMHD)
 * National Institute of Neurological Disorders and Stroke (NINDS)
 * National Institute of Nursing Research (NINR)
 * National Library of Medicine (NLM)
 * Center for Information Technology (CIT)
 * Center for Scientific Review (CSR)
 * Fogarty International Center (FIC)
 * National Center for Advancing Translational Sciences (NCATS)
 * National Center for Complementary and Integrative Health (NCCIH)
 * NIH Clinical Center (NIH CC)

In addition, the National Center for Research Resources operated from April 13, 1962, to December 23, 2011.

ARPA-H
The Advanced Research Projects Agency for Health (ARPA-H) is an entity formerly within the Office of the United States Secretary of Health and Human Services, which was created by Congress in the Consolidated Appropriations Act, 2022. Modeled after DARPA, HSARPA, IARPA, and ARPA-E, it is intended to pursue unconventional research projects through methods not typically used by federal agencies or private sector companies. Secretary Xavier Becerra delegated ARPA-H to the NIH on May 24, 2022. It received $1 billion in appropriations in 2022, and $1.5 billion in 2023, and it is requesting $2.5 billion for 2024.

Previous directors
Source:

title: National Institutes of Health


text:
Talk:French fries

Chips and fries
It is simply wrong to include the British "chip" in an article about "french fries". French fries are by definition thin, and as such french fries are a subset of the chip, and not the other way around - ie a thick cut chip can not be called a "french fry", but a french fry can be called a "think chip". As such to include chips in a discussion of french fries is to show a clear misunderstanding of the chip, and a bias for US english. — Preceding unsigned comment added by Jamspandex (talk • contribs) 20:37, 2 May 2022 (UTC)
 * Agreed. Chips are not a type of french fry, they are chips.  Foreigners don't get to decide the etymology of British food stuffs Marlarkey (talk) 12:55, 9 May 2022 (UTC)
 * There is a distinction, certainly in the minds of Brits as I've said on this page before, but sources either don't make that distinction clear enough, or don't make it at all, to justify a separate page. Find some good quality sources on this and then we can talk.  Without sources, there is nothing that can be done. SpinningSpark 13:36, 9 May 2022 (UTC)
 * Re "French fries are by definition thin", that may be UK usage, but in US usage, French fries includes all sizes, from shoestrings (the fast food format) to steak fries (which can be very thick). --Macrakis (talk) 14:07, 10 May 2022 (UTC)
 * Totally agree that's why the real fries (thin and crispy) are from belgium. French fry is originally more thick with more ponouced taste of potato 2A02:2788:10C4:2C9:69BB:598D:32DE:5F01 (talk) 14:40, 10 July 2024 (UTC)

Really, there are three items "crisps" (US "chips") which are fried *slices* of potatoes and *not* "chips" potatoes; chips (UK name for fried chipped potatoes) and then fries, for the thin cut potato. Really, "Chip" should have it's own item, "French fry" should have it's own item, and "crisps or potato chip" it's own item. In the UK call chips "chips" and not "potato chips", since the "potato" is implicit. For clarification, in France the "french fry" is "pommesfritte", also in Germany, where it is frequently referred to as "pommes". This is the most usual. These translate as "fried potato". It is unfortunate that that in the US they use the name "chip" for something that is not actually made from chips, but from sliced. A little like calling petrol, "gas" when it is not actually a "gas" but a liquid (yes I know it is short for gasoline, and I realise it is somewhat off topic, but is nevertheless an example of US english using words for things which are not actually correct descriptions). — Preceding unsigned comment added by Jamspandex (talk • contribs) 20:37, 2 May 2022 (UTC)
 * Agreed that UK crisps/US potato chips are different from UK chips/US french fries. But French-fried potatoes (pommes frites) are a single grouping, with a variety of thicknesses: very thin (pommes paille), thin (pommes allumettes, similar to fast-food fries), or thick (pomme Pont Neuf or bûches, similar to UK chips and US steak fries). --Macrakis (talk) 02:25, 10 May 2022 (UTC)

I had the same reaction when I got linked to 'french' fries, from 'chips', as an ozzie it pains when Wikipedia 'English' seems to be hijacked as American (no offense). I imagine this has cropped up in many similar situations, surely there is a way to reflect non-americanist articles? Perhaps the topic should be 'Fried Potatoes' with 'French Fries' as a section. ˥ Ǝ Ʉ H Ɔ I Ɯ (talk) 01:00, 24 June 2022 (UTC)
 * British "chips" = American "French fries". It's not that complicated. In British English "French fries" might be a subset of "chips", but everything Brits call "chips" are "French fries" to Americans. This is simply an example of WP:ENGVAR. And since this subject does not have a strong national affiliation, we use the title it was first given (French fries). Which, by the way, is also why the article should be written using American English, contrary to the argument made above. Tad Lincoln (talk) 21:01, 29 September 2022 (UTC)
 * "British "chips" = American "French fries". It's not that complicated." No, it's not. You're simply wrong. Obvious 'French fries' are sometimes sold as 'chips' in UK fast food outlets - kebab, burger, chicken sort of places but 'chips' are most commonly associated with fish and chip SHOPS - the vendors not the dish. Just about everywhere else (including British McDonalds) restaurants, pubs etc sell 'fries' NOT 'French fries, the latter is an expression rarely heard in the UK.
 * There is simply no comparison between a 'chip'(as from a British chip shop or British fish and chip shop) and a 'French fry'. The former is soggy and pulpy, the latter, crisp. The former is a pale yellow-white colour, the fry is dark yellow-brown. The chip is oily, the fry rarely so. Traditionally, the chips are splashed with a synthetic malt vinegar and heavily seasoned with fine salt and then sold over the counter wrapped in heavy paper. This food is not, I can attest from personal experience, much liked by Americans, who know only the French fry.
 * Us Brits clearly understand the difference between chips and (French) fries - as well as the fact that both may be encountered in popular British cuisine. The chip is an important part of British culture and it certainly isn't the place of Americans to lecture us about that. In fact, it's offensive and insulting.86.132.255.75 (talk) 15:35, 17 July 2023 (UTC)

 * How about Canadian? Best of both Englishes, or whatever the plural for English is. IPs are people too 🇺🇸🦅 02:13, 24 October 2023 (UTC)

 * The fact is for every article using North American English (both American and Canadian), there are about five articles using British English.    Maybe that should be added to Wikipedia is fascist, but that essay doesn't exist.     So one of the North American Englishes should be used, just to even things out. IPs are people too 🇺🇸🦅 04:30, 30 October 2023 (UTC)
 * That has no relevance whatsoever to this particular article. Ponsonby100 (talk) 07:51, 30 October 2023 (UTC)
 * I said at the end that the North American Englishes should be used in this article. The use of British English has clearly confused people, and American or Canadian English should be employed. Hell, I'm just going to switch to Canadian. IPs are people too 🇺🇸🦅 08:47, 30 October 2023 (UTC)

Teresa of Ávila
-- you are right, the web site Focus on Belgium is not just a travel promotion site. It is published by the Public Diplomacy Service and also promotes Belgian culture in general. Public diplomacy is basically public relations for countries. Just because it is a branch of the Belgian government does not make it a WP:Reliable source for much of anything, and certainly not culinary history. The article itself is unsigned, has no source references, and confuses "baking" with "frying" (no doubt a bad translation).

We already include Ilegems' claim about Teresa, which should be enough. And although there is evidence that potatoes were grown in her convent, they were surely not white potatoes but sweet potatoes ("Las patatas del siglo de oro"), and there is no evidence that they were fried. All that Teresa said was "La suya recibí, y con ella las patatas y el pipote y siete limones." Nothing about frying. --Macrakis (talk) 16:06, 18 March 2024 (UTC)
 * , Focus on Belgium is an official website of the Belgian government, specifically the Public Diplomacy Service of the Federal Public Service Foreign Affairs, Foreign Trade and Development Cooperation. Thus it is a reliable source including for culinary information. You're dismissing an official website of the Belgian government, because you don't like the information. However, the Belgian government surely doesn't spread false information about their own culinary history. The About Us page says "Focus on Belgium is a website designed to present Belgium. On it, visitors will find precise and factual information about various fields (geography, history, institutions, etc.). The website also presents a series of news articles, providing reliable and verifiable information from independent and recognised sources." -Artanisen (talk) 16:42, 18 March 2024 (UTC)

 * That it is a public diplomacy (i.e. promotional) site tells us nothing, especially when the article is unsigned, unsourced, and contradicts better sources (Caius Apicius = Cristino Álvarez). Oh, and it is not an "official" site in the sense of reflecting the official position of the ministry: "The FPS Foreign Affairs cannot guarantee the accuracy or completeness of the information distributed via its site" . --Macrakis (talk) 17:46, 18 March 2024 (UTC)

Semi-protected edit request on 4 April 2024
The "Global Use" section mentions how fries are being called and sold in the different countries and languages. It says about Belgium:

In Belgium, fries are sold in shops called friteries (French), frietkot/frituur (Belgian French), snackbar (Dutch in The Netherlands)

"frietkot/frituur" is Belgian Dutch, or Flemish, not Belgian French. So it should say:

In Belgium, fries are sold in shops called friteries (French), frietkot/frituur (Belgian Dutch), snackbar (Dutch in The Netherlands)

PhoeniX1860 (talk) 13:26, 4 April 2024 (UTC)

 * I have researched this and can confirm you are correct. However, I've changed it to Flemish instead for consistency with the other text in the paragraph. ― novov (t   c)  08:12, 5 April 2024 (UTC)

Greek
Can be added as a country if refs can be found to confirm that preparation is with feta cheese, fresh parsley and other ingredients. David notMD (talk) 04:43, 9 May 2024 (UTC)

 * There are lots of ways of serving French fries. Anyway, do you have any evidence that adding feta and parsley is a common Greek variant? --Macrakis (talk) 11:13, 9 May 2024 (UTC)
 * Lots of recipe blogs and personal websites, so did not see any I consider reference-worthy. What makes the fries 'Greek' appears to be hand-cut, leave skins on, fried or baked with olive oil, topped with feta cheese and either fresh oregano or parsley. I do not intend to add to list of countries, or an image. David notMD (talk) 10:18, 10 May 2024 (UTC)

Semi-protected edit request on 16 May 2024
In the origin section, specifically this paragraph:

Spain
In 1673, the Chilean Francisco Núñez de Pineda mentioned eating "papas fritas" in 1629 and women "sent fried and stewed potatoes" to the chiefs.

I would change the header to Chile, as it has the first registry of french fries and then continue with the history in Spain. Francisco Núñez de Pineda y Bascuñan is Chilean and his writings are about his experience in Chile, so the heading is misleading as the paragraph do not refer to Spain.

Also, I would rephrase the wording to be clearer: "mentioned eating "papas fritas" in 1629 and women "sent fried and stewed potatoes" to the chiefs." I would change it to

"Wrote about eating "papas fritas" (fried potatoes) in 1629, while he was being captive by the Mapuche (indigenous habitants of Chile), where women used to serve "fried and stewed potatoes" to the chiefs. 200.124.49.227 (talk) 13:13, 16 May 2024 (UTC)

 * Red information icon with gradient background.svg Not done: There is no need to change the header as Chile was owned by Spain. If you object to this reply, please establish consensus before reactivating the request. ABG (Talk/Report any mistakes here) 02:49, 30 May 2024 (UTC)

license: Creative Commons - Attribution Share-Alike - https://creativecommons.org/licenses/by-sa/4.0/

title: Talk:French fries


text:
Talk:National Institutes of Health

Untitled
Initial information from www.nih.gov : "Unless noted otherwise, it is safe to assume that information posted on public Web sites within the "NIH.GOV" domain are considered to be "in the public domain.""

External links modified (February 2018)
Hello fellow Wikipedians,

I have just modified 2 external links on National Institutes of Health. Please take a moment to review my edit. If you have any questions, or need the bot to ignore the links, or the page altogether, please visit this simple FaQ for additional information. I made the following changes:
 * Added archive https://web.archive.org/web/20100308040208/https://www3.niaid.nih.gov/about/organization/dir/overview.htm to http://www3.niaid.nih.gov/about/organization/dir/overview.htm
 * Added archive https://web.archive.org/web/20101106080019/http://search.engrant.com/ to http://search.engrant.com/

When you have finished reviewing my changes, you may follow the instructions on the template below to fix any issues with the URLs.

Cheers.— InternetArchiveBot  (Report bug) 22:03, 13 February 2018 (UTC)

Inconsistent formation date
The infobox says NIH was formed in 1887, but the lead section says it was founded "in the late 1870s". Which one is correct? – numbermaniac  02:09, 24 July 2018 (UTC)

title: Talk:National Institutes of Health


text:
Epidemic typhus

Epidemic typhus, also known as louse-borne typhus, is a form of typhus so named because the disease often causes epidemics following wars and natural disasters where civil life is disrupted. Epidemic typhus is spread to people through contact with infected body lice, in contrast to endemic typhus which is usually transmitted by fleas.

Though typhus has been responsible for millions of deaths throughout history, it is still considered a rare disease that occurs mainly in populations that suffer unhygienic extreme overcrowding. Typhus is most rare in industrialized countries. It occurs primarily in the colder, mountainous regions of central and east Africa, as well as Central and South America. The causative organism is Rickettsia prowazekii, transmitted by the human body louse (Pediculus humanus corporis). Untreated typhus cases have a fatality rate of approximately 40%.

Epidemic typhus should not be confused with murine typhus, which is more endemic to the United States, particularly Southern California and Texas. This form of typhus has similar symptoms but is caused by Rickettsia typhi, is less deadly, and has different vectors for transmission.

Signs and symptoms
Symptoms of this disease typically begin within 2 weeks of contact with the causative organism. Signs/Symptoms may include:
 * Fever
 * Chills
 * Headache
 * Confusion
 * Cough
 * Rapid Breathing
 * Body/Muscle Aches
 * Rash
 * Nausea
 * Vomiting

After 5–6 days, a macular skin eruption develops: first on the upper trunk and spreading to the rest of the body (rarely to the face, palms, or soles of the feet, however).

Brill–Zinsser disease, first described by Nathan Brill in 1913 at Mount Sinai Hospital in New York City, is a mild form of epidemic typhus that recurs in someone after a long period of latency (similar to the relationship between chickenpox and shingles). This recurrence often arises in times of relative immunosuppression, which is often in the context of a person suffering malnutrition or other illnesses. In combination with poor sanitation and hygiene in times of social chaos and upheaval, which enable a greater density of lice, this reactivation is why typhus generates epidemics in such conditions.

Complications
Complications are as follows
 * Myocarditis
 * Endocarditis
 * Mycotic aneurysm
 * Pneumonia
 * Pancreatitis
 * Kidney or bladder infections
 * Acute renal failure
 * Meningitis
 * Encephalitis
 * Myelitis
 * Septic shock

Transmission
Feeding on a human who carries the bacterium infects the louse. R. prowazekii grows in the louse's gut and is excreted in its feces. The louse transmits the disease by biting an uninfected human, who scratches the louse bite (which itches) and rubs the feces into the wound. The incubation period is one to two weeks. R. prowazekii can remain viable and virulent in the dried louse feces for many days. Typhus will eventually kill the louse, though the disease will remain viable for many weeks in the dead louse.

Epidemic typhus has historically occurred during times of war and deprivation. For example, typhus killed millions of prisoners in German Nazi concentration camps during World War II. The unhygenic conditions in camps such as Auschwitz, Theresienstadt, and Bergen-Belsen allowed diseases such as typhus to flourish. Situations in the twenty-first century with potential for a typhus epidemic would include refugee camps during a major famine or natural disaster. In the periods between outbreaks, when human to human transmission occurs less often, the flying squirrel serves as a zoonotic reservoir for the Rickettsia prowazekii bacterium.

In 1916, Henrique da Rocha Lima proved that the bacterium Rickettsia prowazekii was the agent responsible for typhus; he named it after H. T. Ricketts and Stanislaus von Prowazek, two zoologists who had died from typhus while investigating epidemics. Once these crucial facts were recognized, Rudolf Weigl in 1930 was able to fashion a practical and effective vaccine production method. He ground up the insides of infected lice that had been drinking blood. It was, however, very dangerous to produce, and carried a high likelihood of infection to those who were working on it.

A safer mass-production-ready method using egg yolks was developed by Herald R. Cox in 1938. This vaccine was widely available and used extensively by 1943.

Diagnosis
IFA, ELISA or PCR positive after 10 days.

Treatment
The infection is treated with antibiotics. Intravenous fluids and oxygen may be needed to stabilize the patient. There is a significant disparity between the untreated mortality and treated mortality rates: 10-60% untreated versus close to 0% treated with antibiotics within 8 days of initial infection. Tetracycline, chloramphenicol, and doxycycline are commonly used.

Some of the simplest methods of prevention and treatment focus on preventing infestation of body lice. Completely changing the clothing, washing the infested clothing in hot water, and in some cases also treating recently used bedsheets all help to prevent typhus by removing potentially infected lice. Clothes left unworn and unwashed for 7 days also result in the death of both lice and their eggs, as they have no access to a human host. Another form of lice prevention requires dusting infested clothing with a powder consisting of 10% DDT, 1% malathion, or 1% permethrin, which kill lice and their eggs.

Other preventive measures for individuals are to avoid unhygienic, extremely overcrowded areas where the causative organisms can jump from person to person. In addition, they are warned to keep a distance from larger rodents that carry lice, such as rats, squirrels, or opossums.

Before 19th century
During the second year of the Peloponnesian War (430 BC), the city-state of Athens in ancient Greece had an epidemic, known as the Plague of Athens, which killed, among others, Pericles and his two elder sons. The plague returned twice more, in 429 BC and in the winter of 427/6 BC. Epidemic typhus is proposed as a strong candidate for the cause of this disease outbreak, supported by both medical and scholarly opinions.

The first description of typhus was probably given in 1083 at La Cava abbey near Salerno, Italy. In 1546, Girolamo Fracastoro, a Florentine physician, described typhus in his famous treatise on viruses and contagion, De Contagione et Contagiosis Morbis.

Typhus was carried to mainland Europe by soldiers who had been fighting on Cyprus. The first reliable description of the disease appears during the siege of the Emirate of Granada by the Catholic Monarchs in 1489 during the Granada War. These accounts include descriptions of fever and red spots over arms, back and chest, progressing to delirium, gangrenous sores, and the stench of rotting flesh. During the siege, the Catholics lost 3,000 men to enemy action, but an additional 17,000 died of typhus.

Typhus was also common in prisons (and in crowded conditions where lice spread easily), where it was known as Gaol fever or Jail fever. Gaol fever often occurs when prisoners are frequently huddled together in dark, filthy rooms. Imprisonment until the next term of court was often equivalent to a death sentence. Typhus was so infectious that prisoners brought before the court sometimes infected the court itself. Following the Black Assize of Oxford 1577, over 510 died from epidemic typhus, including Speaker Robert Bell, Lord Chief Baron of the Exchequer. The outbreak that followed, between 1577 and 1579, killed about 10% of the English population.

During the Lent assize held at Taunton (1730), typhus caused the death of the Lord Chief Baron of the Exchequer, the High Sheriff of Somerset, the sergeant, and hundreds of other persons. During a time when there were 241 capital offences, more prisoners died from 'gaol fever' than were put to death by all the public executioners in the realm. In 1759 an English authority estimated that each year a quarter of the prisoners had died from gaol fever. In London, typhus frequently broke out among the ill-kept prisoners of Newgate Gaol and moved into the general city population.

19th century
Epidemics occurred in the British Isles and throughout Europe, for instance, during the English Civil War, the Thirty Years' War, and the Napoleonic Wars. Many historians believe that the typhus outbreak among Napoleon's troops is the real reason why he stalled his military campaign into Russia, rather than starvation or the cold. A major epidemic occurred in Ireland between 1816 and 1819, and again in the late 1830s. Another major typhus epidemic occurred during the Great Irish Famine between 1846 and 1849. The Irish typhus spread to England, where it was sometimes called "Irish fever" and was noted for its virulence. It killed people of all social classes since lice were endemic and inescapable, but it hit particularly hard in the lower or "unwashed" social strata. It was carried to North America by the many Irish refugees who fled the famine. In Canada, the 1847 North American typhus epidemic killed more than 20,000 people, mainly Irish immigrants in fever sheds and other forms of quarantine, who had contracted the disease aboard coffin ships. As many as 900,000 deaths have been attributed to the typhus fever during the Crimean War in 1853–1856, and 270,000 to the 1866 Finnish typhus epidemic.

In the United States, a typhus epidemic struck Philadelphia in 1837. The son of Franklin Pierce died in 1843 of a typhus epidemic in Concord, New Hampshire. Several epidemics occurred in Baltimore, Memphis, and Washington, D.C. between 1865 and 1873. Typhus fever was also a significant killer during the American Civil War, although typhoid fever was the more prevalent cause of US Civil War "camp fever." Typhoid is a completely different disease from typhus. Typically more men died on both sides of disease than wounds.

Rudolph Carl Virchow, a physician, anthropologist, and historian attempted to control an outbreak of typhus in Upper Silesia and wrote a 190-page report about it. He concluded that the solution to the outbreak did not lie in individual treatment or by providing small changes in housing, food or clothing, but rather in widespread structural changes to directly address the issue of poverty. Virchow's experience in Upper Silesia led to his observation that "Medicine is a social science". His report led to changes in German public health policy.

20th century
Typhus was endemic in Poland and several neighboring countries prior to World War I (1914–1918). During and shortly after the war, epidemic typhus caused up to three million deaths in Russia, and several million citizens also died in Poland and Romania. Since 1914, many troops, prisoners and even doctors were infected, and at least 150,000 died from typhus in Serbia, 50,000 of whom were prisoners. Delousing stations were established for troops on the Western Front, but the disease ravaged the armies of the Eastern Front. Fatalities were generally between 10 and 40 percent of those infected, and the disease was a major cause of death for those nursing the sick. During World War I and the Russian Civil War between the White and Red, the typhus epidemic caused 2–3 million deaths out of 20–30 million cases in Russia between 1918 and 1922. Typhus caused hundreds of thousands of deaths during World War II. It struck the German Army during Operation Barbarossa, the invasion of Russia, in 1941. In 1942 and 1943 typhus hit French North Africa, Egypt and Iran particularly hard. Typhus epidemics killed inmates in the Nazi concentration camps and death camps such as Auschwitz, Dachau, Theresienstadt, and Bergen-Belsen. Footage shot at Bergen-Belsen concentration camp shows the mass graves for typhus victims. Anne Frank, at age 15, and her sister Margot both died of typhus in the camps. Even larger epidemics in the post-war chaos of Europe were averted only by the widespread use of the newly discovered DDT to kill lice on the millions of refugees and displaced persons.

Following the development of a vaccine during World War II, Western Europe and North America have been able to prevent epidemics. These have usually occurred in Eastern Europe, the Middle East, and parts of Africa, particularly Ethiopia. Naval Medical Research Unit Five worked there with the government on research to attempt to eradicate the disease.

In one of its first major outbreaks since World War II, epidemic typhus reemerged in 1995 in a jail in N'Gozi, Burundi. This outbreak followed the start of the Burundian Civil War in 1993, which caused the displacement of 760,000 people. Refugee camps were crowded and unsanitary, and often far from towns and medical services.

21st century
A 2005 study found seroprevalence of R. prowazekii antibodies in homeless populations in two shelters in Marseille, France. The study noted the "hallmarks of epidemic typhus and relapsing fever".

History of vaccines
Major developments for typhus vaccines started during World War I, as typhus caused high mortality, and threatened the health and readiness for soldiers on the battlefield. Vaccines for typhus, like other vaccines of the time, were classified as either living or killed vaccines. Live vaccines were typically an injection of live agent, and killed vaccines are live cultures of an agent that are chemically inactivated prior to use.

Attempts to create a living vaccine of classical, louse-borne, typhus were attempted by French researchers but these proved unsuccessful. Researchers turned to murine typhus to develop a live vaccine. At the time, murine vaccine was viewed as a less severe alternative to classical typhus. Four versions of a live vaccine cultivated from murine typhus were tested, on a large scale, in 1934.

While the French were making advancements with live vaccines, other European countries were working to develop killed vaccines. During World War II, there were three kinds of potentially useful killed vaccines. All three killed vaccines relied on the cultivation of Rickettsia prowazekii, the organism responsible for typhus. The first attempt at a killed vaccine was developed by Germany, using the Rickettsia prowazekii found in louse feces. The vaccine was tested extensively in Poland between the two world wars and used by the Germans for their troops during their attacks on the Soviet Union.

A second method of growing Rickettsia prowazekii was discovered using the yolk sac of chick embryos. Germans tried several times to use this technique of growing Rickettsia prowazekii but no effort was pushed very far.

The last technique was an extended development of the previously known method of growing murine typhus in rodents. It was discovered that rabbits could be infected, by a similar process, and contract classical typhus instead of murine typhus. Again, while proven to produce suitable Rickettsia prowazekii for vaccine development, this method was not used to produce wartime vaccines.

During WWII, the two major vaccines available were the killed vaccine grown in lice and the live vaccine from France. Neither was used much during the war. The killed, louse-grown vaccine was difficult to manufacture in large enough quantities, and the French vaccine was not believed to be safe enough for use.

The Germans worked to develop their own live vaccine from the urine of typhus victims. While developing a live vaccine, Germany used live Rickettsia prowazekii to test multiple possible vaccines' capabilities. They gave live Rickettsia prowazekii to concentration camp prisoners, using them as a control group for the vaccine tests.

The use of DDT as an effective means of killing lice, the main carrier of typhus, was discovered in Naples.

Biological weapon
Typhus was one of more than a dozen agents that the United States researched as potential biological weapons before President Richard Nixon suspended all non-defensive aspects of the U.S. biological weapons program in 1969.

Poverty and displacement
The CDC lists the following areas as active foci of human epidemic typhus: Andean regions of South America, some parts of Africa; on the other hand, the CDC only recognizes an active enzootic cycle in the United States involving flying squirrels (CDC). Though epidemic typhus is commonly thought to be restricted to areas of the developing world, serological examination of homeless persons in Houston found evidence for exposure to the bacterial pathogens that cause epidemic typhus and murine typhus. A study involving 930 homeless people in Marseille, France, found high rates of seroprevalence to R. prowazekii and a high prevalence of louse-borne infections in the homeless.

Typhus has been increasingly discovered in homeless populations in developed nations. Typhus among homeless populations is especially prevalent as these populations tend to migrate across states and countries, spreading the risk of infection with their movement. The same risk applies to refugees, who travel across country lines, often living in close proximity and unable to maintain necessary hygienic standards to avoid being at risk for catching lice possibly infected with typhus.

Because the typhus-infected lice live in clothing, the prevalence of typhus is also affected by weather, humidity, poverty and lack of hygiene. Lice, and therefore typhus, are more prevalent during colder months, especially winter and early spring. In these seasons, people tend to wear multiple layers of clothing, giving lice more places to go unnoticed by their hosts. This is particularly a problem for poverty-stricken populations as they often do not have multiple sets of clothing, preventing them from practicing good hygiene habits that could prevent louse infestation.

Due to fear of an outbreak of epidemic typhus, the US Government put a typhus quarantine in place in 1917 across the entirety of the US-Mexican border. Sanitation plants were constructed that required immigrants to be thoroughly inspected and bathed before crossing the border. Those who routinely crossed back and forth across the border for work were required to go through the sanitation process weekly, updating their quarantine card with the date of the next week's sanitation. These sanitation border stations remained active over the next two decades, regardless of the disappearance of the typhus threat. This fear of typhus and resulting quarantine and sanitation protocols dramatically hardened the border between the US and Mexico, fostering scientific and popular prejudices against Mexicans. This ultimately intensified racial tensions and fueled efforts to ban immigrants to the US from the Southern Hemisphere because the immigrants were associated with the disease.

Literature

 * (1847) In Jane Eyre by Charlotte Brontë, an outbreak of typhus occurs in Jane's school Lowood, highlighting the unsanitary conditions the girls live in.
 * (1862) In Fathers and Sons by Ivan Turgenev, Evgeny Bazarov dissects a local peasant and dies after contracting typhus.
 * (1886) In the short story "Excellent People" by Anton Chekhov, typhus kills a Russian provincial.
 * (1886) In The Strange Adventures of Captain Dangerous by George Augustus Henry Sala: "We Convicts were all had to the Grate, for the Knight and Alderman would not venture further in, for fear of the Gaol Fever;"
 * (1890) In How the Other Half Lives by Jacob Riis, the effects of typhus fever and smallpox on "Jewtown" are described.
 * (1935) Hans Zinsser's Rats, Lice and History, although a touch outdated on the science, contains many useful cross-references to classical and historical impact of typhus.
 * (1940) in The Don Flows Home to the Sea by Mikhail Sholokhov, numerous characters contract typhus during the Russian Civil War.
 * (1946) In Viktor Frankl's Man's Search for Meaning, Frankl, a Nazi concentration camp prisoner and trained psychiatrist, treats fellow prisoners for delirium due to typhus, while being occasionally affected with the disease himself.
 * (1955) In Vladimir Nabokov's Lolita, Humbert Humbert's childhood sweetheart, Annabel Leigh, dies of typhus.
 * (1956) In Doctor Zhivago by Boris Pasternak, the main character contracts epidemic typhus in the winter following the Russian Revolution, while living in Moscow.
 * (1964) In Nacht (novel) by Edgar Hilsenrath, characters imprisoned in a ghetto in Transnistria during World War II are portrayed infected with and dying of epidemic typhus.
 * (1978) In Patrick O'Brian's novel Desolation Island, an outbreak of "gaol-fever" strikes the crew while sailing aboard the Leopard.
 * (1980–1991) In Maus by Art Spiegelman, Vladek Spiegelman contracts typhus during his imprisonment at the Dachau concentration camp.
 * (1982) There is a typhus epidemic in Chile graphically described in The House of the Spirits by Isabel Allende
 * (1996) In Andrea Barrett's novella Ship Fever, the characters struggle with a typhus outbreak at the Canadian Grosse Isle Quarantine Station during 1847.
 * (2001) Lynn and Gilbert Morris' novel Where Two Seas Met portrays an outbreak of typhus on the island of Bequia in the Grenadines, in 1869.
 * (2004) In Neal Stephenson's The System Of The World, a fictionalized Sir Isaac Newton dies of "gaol fever" before being resurrected by Daniel Waterhouse.

title: Epidemic typhus


text:
SQUID

A SQUID (superconducting quantum interference device) is a very sensitive magnetometer used to measure extremely weak magnetic fields, based on superconducting loops containing Josephson junctions.

SQUIDs are sensitive enough to measure fields as low as 5×10−14 T with a few days of averaged measurements. Their noise levels are as low as 3 fT·Hz−$1/2$. For comparison, a typical refrigerator magnet produces 0.01 tesla (10−2 T), and some processes in animals produce very small magnetic fields between 10−9 T and 10−6 T. SERF atomic magnetometers, invented in the early 2000s are potentially more sensitive and do not require cryogenic refrigeration but are orders of magnitude larger in size (~1 cm3) and must be operated in a near-zero magnetic field.

History and design
There are two main types of SQUID: direct current (DC) and radio frequency (RF). RF SQUIDs can work with only one Josephson junction (superconducting tunnel junction), which might make them cheaper to produce, but are less sensitive.

DC SQUID

The DC SQUID was invented in 1964 by Robert Jaklevic, John J. Lambe, James Mercereau, and Arnold Silver of Ford Research Labs after Brian Josephson postulated the Josephson effect in 1962, and the first Josephson junction was made by John Rowell and Philip Anderson at Bell Labs in 1963. It has two Josephson junctions in parallel in a superconducting loop. It is based on the DC Josephson effect. In the absence of any external magnetic field, the input current $$I$$ splits into the two branches equally. If a small external magnetic field is applied to the superconducting loop, a screening current, $$I_s$$, begins to circulate the loop that generates the magnetic field canceling the applied external flux, and creates an additional Josephson phase which is proportional to this external magnetic flux. The induced current is in the same direction as $$I$$ in one of the branches of the superconducting loop, and is opposite to $$I$$ in the other branch; the total current becomes $$I/2 + I_s$$ in one branch and $$I/2 - I_s$$ in the other. As soon as the current in either branch exceeds the critical current, $$I_c$$, of the Josephson junction, a voltage appears across the junction.

Now suppose the external flux is further increased until it exceeds $$\Phi_0/2$$, half the magnetic flux quantum. Since the flux enclosed by the superconducting loop must be an integer number of flux quanta, instead of screening the flux the SQUID now energetically prefers to increase it to $$\Phi_0$$. The current now flows in the opposite direction, opposing the difference between the admitted flux $$\Phi_0$$ and the external field of just over $$\Phi_0/2$$. The current decreases as the external field is increased, is zero when the flux is exactly $$\Phi_0$$, and again reverses direction as the external field is further increased. Thus, the current changes direction periodically, every time the flux increases by additional half-integer multiple of $$\Phi_0$$, with a change at maximum amperage every half-plus-integer multiple of $$\Phi_0$$ and at zero amps every integer multiple.

If the input current is more than $$I_c$$, then the SQUID always operates in the resistive mode. The voltage, in this case, is thus a function of the applied magnetic field and the period equal to $$\Phi_0$$. Since the current-voltage characteristic of the DC SQUID is hysteretic, a shunt resistance, $$R$$ is connected across the junction to eliminate the hysteresis (in the case of copper oxide based high-temperature superconductors the junction's own intrinsic resistance is usually sufficient). The screening current is the applied flux divided by the self-inductance of the ring. Thus $$\Delta \Phi$$ can be estimated as the function of $$\Delta V$$ (flux to voltage converter) as follows:

 * $$\Delta V = R \cdot \Delta I$$

 * $$2 \cdot \Delta I = 2 \cdot \frac{\Delta \Phi}{L}$$, where $$L$$ is the self inductance of the superconducting ring

 * $$\Delta V = \frac{R}{L} \cdot \Delta \Phi$$

The discussion in this section assumed perfect flux quantization in the loop. However, this is only true for big loops with a large self-inductance. According to the relations, given above, this implies also small current and voltage variations. In practice the self-inductance $$L$$ of the loop is not so large. The general case can be evaluated by introducing a parameter

 * $$\lambda = \frac{i_cL}{\Phi_0}$$

where $$i_c$$ is the critical current of the SQUID. Usually $$\lambda$$ is of order one.

RF SQUID

The RF SQUID was invented in 1967 by Robert Jaklevic, John J. Lambe, Arnold Silver, and James Edward Zimmerman at Ford. It is based on the AC Josephson effect and uses only one Josephson junction. It is less sensitive compared to DC SQUID but is cheaper and easier to manufacture in smaller quantities. Most fundamental measurements in biomagnetism, even of extremely small signals, have been made using RF SQUIDS. The RF SQUID is inductively coupled to a resonant tank circuit. Depending on the external magnetic field, as the SQUID operates in the resistive mode, the effective inductance of the tank circuit changes, thus changing the resonant frequency of the tank circuit. These frequency measurements can be easily taken, and thus the losses which appear as the voltage across the load resistor in the circuit are a periodic function of the applied magnetic flux with a period of $$\Phi_0$$. For a precise mathematical description refer to the original paper by Erné et al.

Materials used
The traditional superconducting materials for SQUIDs are pure niobium or a lead alloy with 10% gold or indium, as pure lead is unstable when its temperature is repeatedly changed. To maintain superconductivity, the entire device needs to operate within a few degrees of absolute zero, cooled with liquid helium.

High-temperature SQUID sensors were developed in the late 1980s. They are made of high-temperature superconductors, particularly YBCO, and are cooled by liquid nitrogen which is cheaper and more easily handled than liquid helium. They are less sensitive than conventional low temperature SQUIDs but good enough for many applications.

In 2006, A proof of concept was shown for CNT-SQUID sensors built with an aluminium loop and a single walled carbon nanotube Josephson junction. The sensors are a few 100 nm in size and operate at 1K or below. Such sensors allow to count spins.

In 2022 a SQUID was constructed on magic angle twisted bilayer graphene (MATBG)

Uses

The extreme sensitivity of SQUIDs makes them ideal for studies in biology. Magnetoencephalography (MEG), for example, uses measurements from an array of SQUIDs to make inferences about neural activity inside brains. Because SQUIDs can operate at acquisition rates much higher than the highest temporal frequency of interest in the signals emitted by the brain (kHz), MEG achieves good temporal resolution. Another area where SQUIDs are used is magnetogastrography, which is concerned with recording the weak magnetic fields of the stomach. A novel application of SQUIDs is the magnetic marker monitoring method, which is used to trace the path of orally applied drugs. In the clinical environment SQUIDs are used in cardiology for magnetic field imaging (MFI), which detects the magnetic field of the heart for diagnosis and risk stratification.

Probably the most common commercial use of SQUIDs is in magnetic property measurement systems (MPMS). These are turn-key systems, made by several manufacturers, that measure the magnetic properties of a material sample. This is typically done over a temperature range from that of 300 mK to roughly 400 K. With the decreasing size of SQUID sensors since the last decade, such sensor can equip the tip of an AFM probe. Such device allows simultaneous measurement of roughness of the surface of a sample and the local magnetic flux.

For example, SQUIDs are being used as detectors to perform magnetic resonance imaging (MRI). While high-field MRI uses precession fields of one to several teslas, SQUID-detected MRI uses measurement fields that lie in the microtesla range. In a conventional MRI system, the signal scales as the square of the measurement frequency (and hence precession field): one power of frequency comes from the thermal polarization of the spins at ambient temperature, while the second power of field comes from the fact that the induced voltage in the pickup coil is proportional to the frequency of the precessing magnetization. In the case of untuned SQUID detection of prepolarized spins, however, the NMR signal strength is independent of precession field, allowing MRI signal detection in extremely weak fields, on the order of Earth's magnetic field. SQUID-detected MRI has advantages over high-field MRI systems, such as the low cost required to build such a system, and its compactness. The principle has been demonstrated by imaging human extremities, and its future application may include tumor screening.

Another application is the scanning SQUID microscope, which uses a SQUID immersed in liquid helium as the probe. The use of SQUIDs in oil prospecting, mineral exploration, earthquake prediction and geothermal energy surveying is becoming more widespread as superconductor technology develops; they are also used as precision movement sensors in a variety of scientific applications, such as the detection of gravitational waves. A SQUID is the sensor in each of the four gyroscopes employed on Gravity Probe B in order to test the limits of the theory of general relativity.

A modified RF SQUID was used to observe the dynamical Casimir effect for the first time.

SQUIDs constructed from super-cooled niobium wire loops are used as the basis for D-Wave Systems 2000Q quantum computer.

Transition-edge sensors
One of the largest uses of SQUIDs is to read out superconducting Transition-edge sensors. Hundreds of thousands of multiplexed SQUIDs coupled to transition-edge sensors are presently being deployed to study the Cosmic microwave background, for X-ray astronomy, to search for dark matter made up of Weakly interacting massive particles, and for spectroscopy at Synchrotron light sources.

Cold dark matter
Advanced SQUIDS called near quantum-limited SQUID amplifiers form the basis of the Axion Dark Matter Experiment (ADMX) at the University of Washington. Axions are a prime candidate for cold dark matter.

Proposed uses
A potential military application exists for use in anti-submarine warfare as a magnetic anomaly detector (MAD) fitted to maritime patrol aircraft.

SQUIDs are used in superparamagnetic relaxometry (SPMR), a technology that utilizes the high magnetic field sensitivity of SQUID sensors and the superparamagnetic properties of magnetite nanoparticles. These nanoparticles are paramagnetic; they have no magnetic moment until exposed to an external field where they become ferromagnetic. After removal of the magnetizing field, the nanoparticles decay from a ferromagnetic state to a paramagnetic state, with a time constant that depends upon the particle size and whether they are bound to an external surface. Measurement of the decaying magnetic field by SQUID sensors is used to detect and localize the nanoparticles. Applications for SPMR may include cancer detection.

title: SQUID


text:
White noise

In signal processing, white noise is a random signal having equal intensity at different frequencies, giving it a constant power spectral density. The term is used with this or similar meanings in many scientific and technical disciplines, including physics, acoustical engineering, telecommunications, and statistical forecasting. White noise refers to a statistical model for signals and signal sources, rather than to any specific signal. White noise draws its name from white light, although light that appears white generally does not have a flat power spectral density over the visible band.

In discrete time, white noise is a discrete signal whose samples are regarded as a sequence of serially uncorrelated random variables with zero mean and finite variance; a single realization of white noise is a random shock. Depending on the context, one may also require that the samples be independent and have identical probability distribution (in other words independent and identically distributed random variables are the simplest representation of white noise). In particular, if each sample has a normal distribution with zero mean, the signal is said to be additive white Gaussian noise.

The samples of a white noise signal may be sequential in time, or arranged along one or more spatial dimensions. In digital image processing, the pixels of a white noise image are typically arranged in a rectangular grid, and are assumed to be independent random variables with uniform probability distribution over some interval. The concept can be defined also for signals spread over more complicated domains, such as a sphere or a torus.

An infinite-bandwidth white noise signal is a purely theoretical construction. The bandwidth of white noise is limited in practice by the mechanism of noise generation, by the transmission medium and by finite observation capabilities. Thus, random signals are considered "white noise" if they are observed to have a flat spectrum over the range of frequencies that are relevant to the context. For an audio signal, the relevant range is the band of audible sound frequencies (between 20 and 20,000 Hz). Such a signal is heard by the human ear as a hissing sound, resembling the /h/ sound in a sustained aspiration. On the other hand, the "sh" sound in "ash" is a colored noise because it has a formant structure. In music and acoustics, the term "white noise" may be used for any signal that has a similar hissing sound.

The term white noise is sometimes used in the context of phylogenetically based statistical methods to refer to a lack of phylogenetic pattern in comparative data. It is sometimes used analogously in nontechnical contexts to mean "random talk without meaningful contents".

Statistical properties
Any distribution of values is possible (although it must have zero DC component). Even a binary signal which can only take on the values 1 or -1 will be white if the sequence is statistically uncorrelated. Noise having a continuous distribution, such as a normal distribution, can of course be white.

It is often incorrectly assumed that Gaussian noise (i.e., noise with a Gaussian amplitude distribution – see normal distribution) necessarily refers to white noise, yet neither property implies the other. Gaussianity refers to the probability distribution with respect to the value, in this context the probability of the signal falling within any particular range of amplitudes, while the term 'white' refers to the way the signal power is distributed (i.e., independently) over time or among frequencies.

One form of white noise is the generalized mean-square derivative of the Wiener process or Brownian motion.

A generalization to random elements on infinite dimensional spaces, such as random fields, is the white noise measure.

Music
White noise is commonly used in the production of electronic music, usually either directly or as an input for a filter to create other types of noise signal. It is used extensively in audio synthesis, typically to recreate percussive instruments such as cymbals or snare drums which have high noise content in their frequency domain. A simple example of white noise is a nonexistent radio station (static).

Electronics engineering
White noise is also used to obtain the impulse response of an electrical circuit, in particular of amplifiers and other audio equipment. It is not used for testing loudspeakers as its spectrum contains too great an amount of high-frequency content. Pink noise, which differs from white noise in that it has equal energy in each octave, is used for testing transducers such as loudspeakers and microphones.

Computing
White noise is used as the basis of some random number generators. For example, Random.org uses a system of atmospheric antennas to generate random digit patterns from sources that can be well-modeled by white noise.

Tinnitus treatment
White noise is a common synthetic noise source used for sound masking by a tinnitus masker. White noise machines and other white noise sources are sold as privacy enhancers and sleep aids (see music and sleep) and to mask tinnitus. The Marpac Sleep-Mate was the first domestic use white noise machine built in 1962 by traveling salesman Jim Buckwalter. Alternatively, the use of an AM radio tuned to unused frequencies ("static") is a simpler and more cost-effective source of white noise. However, white noise generated from a common commercial radio receiver tuned to an unused frequency is extremely vulnerable to being contaminated with spurious signals, such as adjacent radio stations, harmonics from non-adjacent radio stations, electrical equipment in the vicinity of the receiving antenna causing interference, or even atmospheric events such as solar flares and especially lightning.

Work environment
The effects of white noise upon cognitive function are mixed. Recently, a small study found that white noise background stimulation improves cognitive functioning among secondary students with attention deficit hyperactivity disorder (ADHD), while decreasing performance of non-ADHD students. Other work indicates it is effective in improving the mood and performance of workers by masking background office noise, but decreases cognitive performance in complex card sorting tasks.

Similarly, an experiment was carried out on sixty-six healthy participants to observe the benefits of using white noise in a learning environment. The experiment involved the participants identifying different images whilst having different sounds in the background. Overall the experiment showed that white noise does in fact have benefits in relation to learning. The experiments showed that white noise improved the participants' learning abilities and their recognition memory slightly.

White noise vector
A random vector (that is, a random variable with values in Rn) is said to be a white noise vector or white random vector if its components each have a probability distribution with zero mean and finite variance, and are statistically independent: that is, their joint probability distribution must be the product of the distributions of the individual components.

A necessary (but, in general, not sufficient) condition for statistical independence of two variables is that they be statistically uncorrelated; that is, their covariance is zero. Therefore, the covariance matrix R of the components of a white noise vector w with n elements must be an n by n diagonal matrix, where each diagonal element Rii is the variance of component wi; and the correlation matrix must be the n by n identity matrix.

If, in addition to being independent, every variable in w also has a normal distribution with zero mean and the same variance $$\sigma^2$$, w is said to be a Gaussian white noise vector. In that case, the joint distribution of w is a multivariate normal distribution; the independence between the variables then implies that the distribution has spherical symmetry in n-dimensional space. Therefore, any orthogonal transformation of the vector will result in a Gaussian white random vector. In particular, under most types of discrete Fourier transform, such as FFT and Hartley, the transform W of w will be a Gaussian white noise vector, too; that is, the n Fourier coefficients of w will be independent Gaussian variables with zero mean and the same variance $$\sigma^2$$.

The power spectrum P of a random vector w can be defined as the expected value of the squared modulus of each coefficient of its Fourier transform W, that is, Pi = E(|Wi|2). Under that definition, a Gaussian white noise vector will have a perfectly flat power spectrum, with Pi = σ2 for all i.

If w is a white random vector, but not a Gaussian one, its Fourier coefficients Wi will not be completely independent of each other; although for large n and common probability distributions the dependencies are very subtle, and their pairwise correlations can be assumed to be zero.

Often the weaker condition "statistically uncorrelated" is used in the definition of white noise, instead of "statistically independent". However, some of the commonly expected properties of white noise (such as flat power spectrum) may not hold for this weaker version. Under this assumption, the stricter version can be referred to explicitly as independent white noise vector. Other authors use strongly white and weakly white instead.

An example of a random vector that is "Gaussian white noise" in the weak but not in the strong sense is $$x=[x_1,x_2]$$ where $$x_1$$ is a normal random variable with zero mean, and $$x_2$$ is equal to $$+x_1$$ or to $$-x_1$$, with equal probability. These two variables are uncorrelated and individually normally distributed, but they are not jointly normally distributed and are not independent. If $$x$$ is rotated by 45 degrees, its two components will still be uncorrelated, but their distribution will no longer be normal.

In some situations, one may relax the definition by allowing each component of a white random vector $$w$$ to have non-zero expected value $$\mu$$. In image processing especially, where samples are typically restricted to positive values, one often takes $$\mu$$ to be one half of the maximum sample value. In that case, the Fourier coefficient $$W_0$$ corresponding to the zero-frequency component (essentially, the average of the $$w_i$$) will also have a non-zero expected value $$\mu\sqrt{n}$$; and the power spectrum $$P$$ will be flat only over the non-zero frequencies.

Discrete-time white noise
A discrete-time stochastic process $$W(n)$$ is a generalization of a random vector with a finite number of components to infinitely many components. A discrete-time stochastic process $$W(n)$$ is called white noise if its mean is equal to zero for all $$n$$, i.e. $$\operatorname{E}[W(n)] = 0$$ and if the autocorrelation function $$R_{W}(n) = \operatorname{E}[W(k+n)W(k)]$$ has a nonzero value only for $$n = 0$$, i.e. $$R_{W}(n) = \sigma^2 \delta(n)$$.

Continuous-time white noise
In order to define the notion of "white noise" in the theory of continuous-time signals, one must replace the concept of a "random vector" by a continuous-time random signal; that is, a random process that generates a function $$w$$ of a real-valued parameter $$t$$.

Such a process is said to be white noise in the strongest sense if the value $$w(t)$$ for any time $$t$$ is a random variable that is statistically independent of its entire history before $$t$$. A weaker definition requires independence only between the values $$w(t_1)$$ and $$w(t_2)$$ at every pair of distinct times $$t_1$$ and $$t_2$$. An even weaker definition requires only that such pairs $$w(t_1)$$ and $$w(t_2)$$ be uncorrelated. As in the discrete case, some authors adopt the weaker definition for "white noise", and use the qualifier independent to refer to either of the stronger definitions. Others use weakly white and strongly white to distinguish between them.

However, a precise definition of these concepts is not trivial, because some quantities that are finite sums in the finite discrete case must be replaced by integrals that may not converge. Indeed, the set of all possible instances of a signal $$w$$ is no longer a finite-dimensional space $$\mathbb{R}^n$$, but an infinite-dimensional function space. Moreover, by any definition a white noise signal $$w$$ would have to be essentially discontinuous at every point; therefore even the simplest operations on $$w$$, like integration over a finite interval, require advanced mathematical machinery.

Some authors require each value $$w(t)$$ to be a real-valued random variable with expectation $$\mu$$ and some finite variance $$\sigma^2$$. Then the covariance $$\mathrm{E}(w(t_1)\cdot w(t_2))$$ between the values at two times $$t_1$$ and $$t_2$$ is well-defined: it is zero if the times are distinct, and $$\sigma^2$$ if they are equal. However, by this definition, the integral
 * $$W_{[a,a+r]} = \int_a^{a+r} w(t)\, dt$$

over any interval with positive width $$r$$ would be simply the width times the expectation: $$r\mu$$. This property renders the concept inadequate as a model of "white noise" signals either in a physical or mathematical sense.

Therefore, most authors define the signal $$w$$ indirectly by specifying random values for the integrals of $$w(t)$$ and $$|w(t)|^2$$ over each interval $$[a,a+r]$$. In this approach, however, the value of $$w(t)$$ at an isolated time cannot be defined as a real-valued random variable. Also the covariance $$\mathrm{E}(w(t_1)\cdot w(t_2))$$ becomes infinite when $$t_1=t_2$$; and the autocorrelation function $$\mathrm{R}(t_1,t_2)$$ must be defined as $$N \delta(t_1-t_2)$$, where $$N$$ is some real constant and $$\delta$$ is Dirac's "function".

In this approach, one usually specifies that the integral $$W_I$$ of $$w(t)$$ over an interval $$I=[a,b]$$ is a real random variable with normal distribution, zero mean, and variance $$(b-a)\sigma^2$$; and also that the covariance $$\mathrm{E}(W_I\cdot W_J)$$ of the integrals $$W_I$$, $$W_J$$ is $$r\sigma^2$$, where $$r$$ is the width of the intersection $$I\cap J$$ of the two intervals $$I,J$$. This model is called a Gaussian white noise signal (or process).

In the mathematical field known as white noise analysis, a Gaussian white noise $$w$$ is defined as a stochastic tempered distribution, i.e. a random variable with values in the space $$\mathcal S'(\mathbb R)$$ of tempered distributions. Analogous to the case for finite-dimensional random vectors, a probability law on the infinite-dimensional space $$\mathcal S'(\mathbb R)$$ can be defined via its characteristic function (existence and uniqueness are guaranteed by an extension of the Bochner–Minlos theorem, which goes under the name Bochner–Minlos–Sazanov theorem); analogously to the case of the multivariate normal distribution $$X \sim \mathcal N_n (\mu, \Sigma )$$, which has characteristic function
 * $$\forall k \in \mathbb R^n: \quad \mathrm{E}(\mathrm e^{\mathrm{i} \langle k, X \rangle }) = \mathrm e^{\mathrm i \langle k, \mu \rangle - \frac 1 2 \langle k, \Sigma k \rangle } ,$$

the white noise $$w : \Omega \to \mathcal S'(\mathbb R)$$ must satisfy
 * $$\forall \varphi \in \mathcal S (\mathbb R) : \quad \mathrm{E}(\mathrm e^{\mathrm{i} \langle w, \varphi \rangle }) = \mathrm e^{- \frac 1 2 \| \varphi \|_2^2},$$

where $$\langle w, \varphi \rangle$$ is the natural pairing of the tempered distribution $$w(\omega)$$ with the Schwartz function $$\varphi$$, taken scenariowise for $$\omega \in \Omega$$, and $$\| \varphi \|_2^2 = \int_{\mathbb R} \vert \varphi (x) \vert^2\,\mathrm d x $$.

Time series analysis and regression
In statistics and econometrics one often assumes that an observed series of data values is the sum of the values generated by a deterministic linear process, depending on certain independent (explanatory) variables, and on a series of random noise values. Then regression analysis is used to infer the parameters of the model process from the observed data, e.g. by ordinary least squares, and to test the null hypothesis that each of the parameters is zero against the alternative hypothesis that it is non-zero. Hypothesis testing typically assumes that the noise values are mutually uncorrelated with zero mean and have the same Gaussian probability distribution – in other words, that the noise is Gaussian white (not just white). If there is non-zero correlation between the noise values underlying different observations then the estimated model parameters are still unbiased, but estimates of their uncertainties (such as confidence intervals) will be biased (not accurate on average). This is also true if the noise is heteroskedastic – that is, if it has different variances for different data points.

Alternatively, in the subset of regression analysis known as time series analysis there are often no explanatory variables other than the past values of the variable being modeled (the dependent variable). In this case the noise process is often modeled as a moving average process, in which the current value of the dependent variable depends on current and past values of a sequential white noise process.

Random vector transformations
These two ideas are crucial in applications such as channel estimation and channel equalization in communications and audio. These concepts are also used in data compression.

In particular, by a suitable linear transformation (a coloring transformation), a white random vector can be used to produce a "non-white" random vector (that is, a list of random variables) whose elements have a prescribed covariance matrix. Conversely, a random vector with known covariance matrix can be transformed into a white random vector by a suitable whitening transformation.

Generation
White noise may be generated digitally with a digital signal processor, microprocessor, or microcontroller. Generating white noise typically entails feeding an appropriate stream of random numbers to a digital-to-analog converter. The quality of the white noise will depend on the quality of the algorithm used.

Informal use
The term is sometimes used as a colloquialism to describe a backdrop of ambient sound, creating an indistinct or seamless commotion. Following are some examples:

 * Chatter from multiple conversations within the acoustics of a confined space.
 * The pleonastic jargon used by politicians to mask a point that they don't want noticed.
 * Music that is disagreeable, harsh, dissonant or discordant with no melody.

The term can also be used metaphorically, as in the novel White Noise (1985) by Don DeLillo which explores the symptoms of modern culture that came together so as to make it difficult for an individual to actualize their ideas and personality.

title: White noise