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The first computer-based speech-synthesis systems originated in the late 1950s. Noriko Umeda et al. developed the first general English text-to-speech system in 1968, at the Electrotechnical Laboratory in Japan. In 1961, physicist John Larry Kelly, Jr and his colleague Louis Gerstman used an IBM 704 computer to synthes... | Speech synthesis | Wikipedia | 480 | 42799 | https://en.wikipedia.org/wiki/Speech%20synthesis | Technology | Media and communication | null | vital_articles |
Dominant systems in the 1980s and 1990s were the DECtalk system, based largely on the work of Dennis Klatt at MIT, and the Bell Labs system; the latter was one of the first multilingual language-independent systems, making extensive use of natural language processing methods.
Handheld electronics featuring speech synt... | Speech synthesis | Wikipedia | 484 | 42799 | https://en.wikipedia.org/wiki/Speech%20synthesis | Technology | Media and communication | null | vital_articles |
The two primary technologies generating synthetic speech waveforms are concatenative synthesis and formant synthesis. Each technology has strengths and weaknesses, and the intended uses of a synthesis system will typically determine which approach is used.
Concatenation synthesis
Concatenative synthesis is based on ... | Speech synthesis | Wikipedia | 506 | 42799 | https://en.wikipedia.org/wiki/Speech%20synthesis | Technology | Media and communication | null | vital_articles |
Diphone synthesis uses a minimal speech database containing all the diphones (sound-to-sound transitions) occurring in a language. The number of diphones depends on the phonotactics of the language: for example, Spanish has about 800 diphones, and German about 2500. In diphone synthesis, only one example of each diphon... | Speech synthesis | Wikipedia | 392 | 42799 | https://en.wikipedia.org/wiki/Speech%20synthesis | Technology | Media and communication | null | vital_articles |
Because these systems are limited by the words and phrases in their databases, they are not general-purpose and can only synthesize the combinations of words and phrases with which they have been preprogrammed. The blending of words within naturally spoken language however can still cause problems unless the many varia... | Speech synthesis | Wikipedia | 460 | 42799 | https://en.wikipedia.org/wiki/Speech%20synthesis | Technology | Media and communication | null | vital_articles |
Examples of non-real-time but highly accurate intonation control in formant synthesis include the work done in the late 1970s for the Texas Instruments toy Speak & Spell, and in the early 1980s Sega arcade machines and in many Atari, Inc. arcade games using the TMS5220 LPC Chips. Creating proper intonation for these pr... | Speech synthesis | Wikipedia | 503 | 42799 | https://en.wikipedia.org/wiki/Speech%20synthesis | Technology | Media and communication | null | vital_articles |
Sinewave synthesis is a technique for synthesizing speech by replacing the formants (main bands of energy) with pure tone whistles.
Deep learning-based synthesis
Deep learning speech synthesis uses deep neural networks (DNN) to produce artificial speech from text (text-to-speech) or spectrum (vocoder).
The deep neur... | Speech synthesis | Wikipedia | 470 | 42799 | https://en.wikipedia.org/wiki/Speech%20synthesis | Technology | Media and communication | null | vital_articles |
Audio deepfakes
In 2023, VICE reporter Joseph Cox published findings that he had recorded five minutes of himself talking and then used a tool developed by ElevenLabs to create voice deepfakes that defeated a bank's voice-authentication system.
Challenges
Text normalization challenges
The process of normalizing te... | Speech synthesis | Wikipedia | 481 | 42799 | https://en.wikipedia.org/wiki/Speech%20synthesis | Technology | Media and communication | null | vital_articles |
Similarly, abbreviations can be ambiguous. For example, the abbreviation "in" for "inches" must be differentiated from the word "in", and the address "12 St John St." uses the same abbreviation for both "Saint" and "Street". TTS systems with intelligent front ends can make educated guesses about ambiguous abbreviations... | Speech synthesis | Wikipedia | 428 | 42799 | https://en.wikipedia.org/wiki/Speech%20synthesis | Technology | Media and communication | null | vital_articles |
Languages with a phonemic orthography have a very regular writing system, and the prediction of the pronunciation of words based on their spellings is quite successful. Speech synthesis systems for such languages often use the rule-based method extensively, resorting to dictionaries only for those few words, like forei... | Speech synthesis | Wikipedia | 486 | 42799 | https://en.wikipedia.org/wiki/Speech%20synthesis | Technology | Media and communication | null | vital_articles |
In the early 1980s, TI was known as a pioneer in speech synthesis, and a highly popular plug-in speech synthesizer module was available for the TI-99/4 and 4A. Speech synthesizers were offered free with the purchase of a number of cartridges and were used by many TI-written video games (games offered with speech during... | Speech synthesis | Wikipedia | 502 | 42799 | https://en.wikipedia.org/wiki/Speech%20synthesis | Technology | Media and communication | null | vital_articles |
The Atari ST computers were sold with "stspeech.tos" on floppy disk.
Apple
The first speech system integrated into an operating system that shipped in quantity was Apple Computer's MacInTalk. The software was licensed from third-party developers Joseph Katz and Mark Barton (later, SoftVoice, Inc.) and was featured d... | Speech synthesis | Wikipedia | 414 | 42799 | https://en.wikipedia.org/wiki/Speech%20synthesis | Technology | Media and communication | null | vital_articles |
The second operating system to feature advanced speech synthesis capabilities was AmigaOS, introduced in 1985. The voice synthesis was licensed by Commodore International from SoftVoice, Inc., who also developed the original MacinTalk text-to-speech system. It featured a complete system of voice emulation for American ... | Speech synthesis | Wikipedia | 485 | 42799 | https://en.wikipedia.org/wiki/Speech%20synthesis | Technology | Media and communication | null | vital_articles |
Text-to-speech systems
Text-to-speech (TTS) refers to the ability of computers to read text aloud. A TTS engine converts written text to a phonemic representation, then converts the phonemic representation to waveforms that can be output as sound. TTS engines with different languages, dialects and specialized vocabular... | Speech synthesis | Wikipedia | 421 | 42799 | https://en.wikipedia.org/wiki/Speech%20synthesis | Technology | Media and communication | null | vital_articles |
Others
Following the commercial failure of the hardware-based Intellivoice, gaming developers sparingly used software synthesis in later games. Earlier systems from Atari, such as the Atari 5200 (Baseball) and the Atari 2600 (Quadrun and Open Sesame), also had games utilizing software synthesis.
Some e-book readers,... | Speech synthesis | Wikipedia | 426 | 42799 | https://en.wikipedia.org/wiki/Speech%20synthesis | Technology | Media and communication | null | vital_articles |
This increases the stress on the disinformation situation coupled with the facts that
Human image synthesis since the early 2000s has improved beyond the point of human's inability to tell a real human imaged with a real camera from a simulation of a human imaged with a simulation of a camera.
2D video forgery tech... | Speech synthesis | Wikipedia | 355 | 42799 | https://en.wikipedia.org/wiki/Speech%20synthesis | Technology | Media and communication | null | vital_articles |
Speech synthesis has long been a vital assistive technology tool and its application in this area is significant and widespread. It allows environmental barriers to be removed for people with a wide range of disabilities. The longest application has been in the use of screen readers for people with visual impairment, b... | Speech synthesis | Wikipedia | 456 | 42799 | https://en.wikipedia.org/wiki/Speech%20synthesis | Technology | Media and communication | null | vital_articles |
Content creators have used voice cloning tools to recreate their voices for podcasts, narration, and comedy shows. Publishers and authors have also used such software to narrate audiobooks and newsletters. Another area of application is AI video creation with talking heads. Webapps and video editors like Elai.io or Syn... | Speech synthesis | Wikipedia | 191 | 42799 | https://en.wikipedia.org/wiki/Speech%20synthesis | Technology | Media and communication | null | vital_articles |
In meteorology, a cyclone () is a large air mass that rotates around a strong center of low atmospheric pressure, counterclockwise in the Northern Hemisphere and clockwise in the Southern Hemisphere as viewed from above (opposite to an anticyclone). Cyclones are characterized by inward-spiraling winds that rotate abou... | Cyclone | Wikipedia | 444 | 42806 | https://en.wikipedia.org/wiki/Cyclone | Physical sciences | Atmospheric circulation | null | vital_articles |
Tropical cyclogenesis describes the process of development of tropical cyclones. Tropical cyclones form due to latent heat driven by significant thunderstorm activity, and are warm core. Cyclones can transition between extratropical, subtropical, and tropical phases. Mesocyclones form as warm core cyclones over land, a... | Cyclone | Wikipedia | 485 | 42806 | https://en.wikipedia.org/wiki/Cyclone | Physical sciences | Atmospheric circulation | null | vital_articles |
Cyclogenesis is the development or strengthening of cyclonic circulation in the atmosphere. Cyclogenesis is an umbrella term for several different processes that all result in the development of some sort of cyclone. It can occur at various scales, from the microscale to the synoptic scale.
Extratropical cyclones begi... | Cyclone | Wikipedia | 447 | 42806 | https://en.wikipedia.org/wiki/Cyclone | Physical sciences | Atmospheric circulation | null | vital_articles |
Tropical cyclogenesis is the development and strengthening of a tropical cyclone. The mechanisms by which tropical cyclogenesis occurs are distinctly different from those that produce mid-latitude cyclones. Tropical cyclogenesis, the development of a warm-core cyclone, begins with significant convection in a favorable ... | Cyclone | Wikipedia | 494 | 42806 | https://en.wikipedia.org/wiki/Cyclone | Physical sciences | Atmospheric circulation | null | vital_articles |
A polar low is a small-scale, short-lived atmospheric low-pressure system (depression) that is found over the ocean areas poleward of the main polar front in both the Northern and Southern Hemispheres. Polar lows were first identified on the meteorological satellite imagery that became available in the 1960s, which rev... | Cyclone | Wikipedia | 471 | 42806 | https://en.wikipedia.org/wiki/Cyclone | Physical sciences | Atmospheric circulation | null | vital_articles |
Since they form from extratropical cyclones, which have colder temperatures aloft than normally found in the tropics, the sea surface temperatures required is around 23 degrees Celsius (73 °F) for their formation, which is three degrees Celsius (5 °F) lower than for tropical cyclones. This means that subtropical cyclo... | Cyclone | Wikipedia | 310 | 42806 | https://en.wikipedia.org/wiki/Cyclone | Physical sciences | Atmospheric circulation | null | vital_articles |
While tropical cyclones can produce extremely powerful winds and torrential rain, they are also able to produce high waves and a damaging storm surge. Their winds increase the wave size, and in so doing they draw more heat and moisture into their system, thereby increasing their strength. They develop over large bodies... | Cyclone | Wikipedia | 384 | 42806 | https://en.wikipedia.org/wiki/Cyclone | Physical sciences | Atmospheric circulation | null | vital_articles |
A polar, sub-polar, or Arctic cyclone (also known as a polar vortex) is a vast area of low pressure that strengthens in the winter and weakens in the summer. A polar cyclone is a low-pressure weather system, usually spanning to , in which the air circulates in a counterclockwise direction in the northern hemisphere, a... | Cyclone | Wikipedia | 508 | 42806 | https://en.wikipedia.org/wiki/Cyclone | Physical sciences | Atmospheric circulation | null | vital_articles |
Mesocyclone
A mesocyclone is a vortex of air, to in diameter (the mesoscale of meteorology), within a convective storm. Air rises and rotates around a vertical axis, usually in the same direction as low-pressure systems in both northern and southern hemisphere. They are most often cyclonic, that is, associated with ... | Cyclone | Wikipedia | 453 | 42806 | https://en.wikipedia.org/wiki/Cyclone | Physical sciences | Atmospheric circulation | null | vital_articles |
Cyclones are not unique to Earth. Cyclonic storms are common on giant planets, such as the Small Dark Spot on Neptune. It is about one third the diameter of the Great Dark Spot and received the nickname "Wizard's Eye" because it looks like an eye. This appearance is caused by a white cloud in the middle of the Wizard's... | Cyclone | Wikipedia | 129 | 42806 | https://en.wikipedia.org/wiki/Cyclone | Physical sciences | Atmospheric circulation | null | vital_articles |
Radio frequency (RF) is the oscillation rate of an alternating electric current or voltage or of a magnetic, electric or electromagnetic field or mechanical system in the frequency range from around to around . This is roughly between the upper limit of audio frequencies and the lower limit of infrared frequencies, an... | Radio frequency | Wikipedia | 478 | 42852 | https://en.wikipedia.org/wiki/Radio%20frequency | Physical sciences | Waves | Physics | vital_articles |
The radio spectrum of frequencies is divided into bands with conventional names designated by the International Telecommunication Union (ITU):
{| class="wikitable" style="text-align:right"
|-
! scope="col" rowspan="2" | Frequencyrange !! scope="col" rowspan="2" | Wavelengthrange !! scope="col" colspan="2" | ITU designa... | Radio frequency | Wikipedia | 507 | 42852 | https://en.wikipedia.org/wiki/Radio%20frequency | Physical sciences | Waves | Physics | vital_articles |
| 1 m – 100 mm|| Ultra high frequency || style="text-align:center" | UHF || style="text-align:center" | UHF, L, S
|-
! scope="row" | 3–30 GHz
| 100–10 mm|| Super high frequency || style="text-align:center" | SHF || style="text-align:center" | S, C, X, Ku, K, Ka
|-
! scope="row" | 30–300 GHz
| 10–1 mm|| Extremely high... | Radio frequency | Wikipedia | 208 | 42852 | https://en.wikipedia.org/wiki/Radio%20frequency | Physical sciences | Waves | Physics | vital_articles |
Frequencies of 1 GHz and above are conventionally called microwave, while frequencies of 30 GHz and above are designated millimeter wave.
More detailed band designations are given by the standard IEEE letter- band frequency designations and the EU/NATO frequency designations.
Applications
Communications
Radio freque... | Radio frequency | Wikipedia | 368 | 42852 | https://en.wikipedia.org/wiki/Radio%20frequency | Physical sciences | Waves | Physics | vital_articles |
The human genome is a complete set of nucleic acid sequences for humans, encoded as the DNA within each of the 24 distinct chromosomes in the cell nucleus. A small DNA molecule is found within individual mitochondria. These are usually treated separately as the nuclear genome and the mitochondrial genome. Human genomes... | Human genome | Wikipedia | 407 | 42888 | https://en.wikipedia.org/wiki/Human%20genome | Biology and health sciences | Genetics and taxonomy | null | vital_articles |
The current version of the standard reference genome is called GRCh38.p14 (July 2023). It consists of 22 autosomes plus one copy of the X chromosome and one copy of the Y chromosome. It contains approximately 3.1 billion base pairs (3.1 Gb or 3.1 x 109 bp). This represents the size of a composite genome based on data f... | Human genome | Wikipedia | 511 | 42888 | https://en.wikipedia.org/wiki/Human%20genome | Biology and health sciences | Genetics and taxonomy | null | vital_articles |
Exon sequences consist of coding DNA and untranslated regions (UTRs) at either end of the mature mRNA. The total amount of coding DNA is about 1-2% of the genome.
Many people divide the genome into coding and non-coding DNA based on the idea that coding DNA is the most important functional component of the genome. Abo... | Human genome | Wikipedia | 453 | 42888 | https://en.wikipedia.org/wiki/Human%20genome | Biology and health sciences | Genetics and taxonomy | null | vital_articles |
Regulatory DNA sequences
The human genome has many different regulatory sequences which are crucial to controlling gene expression. Conservative estimates indicate that these sequences make up 8% of the genome, however extrapolations from the ENCODE project give that 20 or more of the genome is gene regulatory sequenc... | Human genome | Wikipedia | 398 | 42888 | https://en.wikipedia.org/wiki/Human%20genome | Biology and health sciences | Genetics and taxonomy | null | vital_articles |
Repeated sequences of fewer than ten nucleotides (e.g. the dinucleotide repeat (AC)n) are termed microsatellite sequences. Among the microsatellite sequences, trinucleotide repeats are of particular importance, as sometimes occur within coding regions of genes for proteins and may lead to genetic disorders. For example... | Human genome | Wikipedia | 488 | 42888 | https://en.wikipedia.org/wiki/Human%20genome | Biology and health sciences | Genetics and taxonomy | null | vital_articles |
There is no consensus on what constitutes a "functional" element in the genome since geneticists, evolutionary biologists, and molecular biologists employ different definitions and methods. Due to the ambiguity in the terminology, different schools of thought have emerged. In evolutionary definitions, "functional" DNA,... | Human genome | Wikipedia | 506 | 42888 | https://en.wikipedia.org/wiki/Human%20genome | Biology and health sciences | Genetics and taxonomy | null | vital_articles |
By 2018, the total number of genes had been raised to at least 46,831, plus another 2300 micro-RNA genes. A 2018 population survey found another 300 million bases of human genome that was not in the reference sequence. Prior to the acquisition of the full genome sequence, estimates of the number of human genes ranged f... | Human genome | Wikipedia | 502 | 42888 | https://en.wikipedia.org/wiki/Human%20genome | Biology and health sciences | Genetics and taxonomy | null | vital_articles |
There are several important points concerning the human reference genome:
The HRG is a haploid sequence. Each chromosome is represented once.
The HRG is a composite sequence, and does not correspond to any actual human individual.
The HRG is periodically updated to correct errors, ambiguities, and unknown "gaps".
T... | Human genome | Wikipedia | 492 | 42888 | https://en.wikipedia.org/wiki/Human%20genome | Biology and health sciences | Genetics and taxonomy | null | vital_articles |
Whereas a genome sequence lists the order of every DNA base in a genome, a genome map identifies the landmarks. A genome map is less detailed than a genome sequence and aids in navigating around the genome.
An example of a variation map is the HapMap being developed by the International HapMap Project. The HapMap is a... | Human genome | Wikipedia | 417 | 42888 | https://en.wikipedia.org/wiki/Human%20genome | Biology and health sciences | Genetics and taxonomy | null | vital_articles |
Single-nucleotide polymorphisms (SNPs) do not occur homogeneously across the human genome. In fact, there is enormous diversity in SNP frequency between genes, reflecting different selective pressures on each gene as well as different mutation and recombination rates across the genome. However, studies on SNPs are bias... | Human genome | Wikipedia | 308 | 42888 | https://en.wikipedia.org/wiki/Human%20genome | Biology and health sciences | Genetics and taxonomy | null | vital_articles |
The first personal genome sequence to be determined was that of Craig Venter in 2007. Personal genomes had not been sequenced in the public Human Genome Project to protect the identity of volunteers who provided DNA samples. That sequence was derived from the DNA of several volunteers from a diverse population. However... | Human genome | Wikipedia | 493 | 42888 | https://en.wikipedia.org/wiki/Human%20genome | Biology and health sciences | Genetics and taxonomy | null | vital_articles |
In humans, gene knockouts naturally occur as heterozygous or homozygous loss-of-function gene knockouts. These knockouts are often difficult to distinguish, especially within heterogeneous genetic backgrounds. They are also difficult to find as they occur in low frequencies.
Populations with high rates of consanguinit... | Human genome | Wikipedia | 378 | 42888 | https://en.wikipedia.org/wiki/Human%20genome | Biology and health sciences | Genetics and taxonomy | null | vital_articles |
Most aspects of human biology involve both genetic (inherited) and non-genetic (environmental) factors. Some inherited variation influences aspects of our biology that are not medical in nature (height, eye color, ability to taste or smell certain compounds, etc.). Moreover, some genetic disorders only cause disease in... | Human genome | Wikipedia | 378 | 42888 | https://en.wikipedia.org/wiki/Human%20genome | Biology and health sciences | Genetics and taxonomy | null | vital_articles |
There are many different kinds of DNA sequence variation, ranging from complete extra or missing chromosomes down to single nucleotide changes. It is generally presumed that much naturally occurring genetic variation in human populations is phenotypically neutral, i.e., has little or no detectable effect on the physiol... | Human genome | Wikipedia | 371 | 42888 | https://en.wikipedia.org/wiki/Human%20genome | Biology and health sciences | Genetics and taxonomy | null | vital_articles |
Genome sequencing is now able to narrow the genome down to specific locations to more accurately find mutations that will result in a genetic disorder. Copy number variants (CNVs) and single nucleotide variants (SNVs) are also able to be detected at the same time as genome sequencing with newer sequencing procedures av... | Human genome | Wikipedia | 401 | 42888 | https://en.wikipedia.org/wiki/Human%20genome | Biology and health sciences | Genetics and taxonomy | null | vital_articles |
In other words, the considerable observable differences between humans and chimps may be due as much or more to genome level variation in the number, function and expression of genes rather than DNA sequence changes in shared genes. Indeed, even within humans, there has been found to be a previously unappreciated amoun... | Human genome | Wikipedia | 400 | 42888 | https://en.wikipedia.org/wiki/Human%20genome | Biology and health sciences | Genetics and taxonomy | null | vital_articles |
Due to the damage induced by the exposure to Reactive Oxygen Species mitochondrial DNA (mtDNA) has a more rapid rate of variation than nuclear DNA. This 20-fold higher mutation rate allows mtDNA to be used for more accurate tracing of maternal ancestry. Studies of mtDNA in populations have allowed ancient migration pat... | Human genome | Wikipedia | 401 | 42888 | https://en.wikipedia.org/wiki/Human%20genome | Biology and health sciences | Genetics and taxonomy | null | vital_articles |
Epigenetic patterns can be identified between tissues within an individual as well as between individuals themselves. Identical genes that have differences only in their epigenetic state are called epialleles. Epialleles can be placed into three categories: those directly determined by an individual's genotype, those i... | Human genome | Wikipedia | 145 | 42888 | https://en.wikipedia.org/wiki/Human%20genome | Biology and health sciences | Genetics and taxonomy | null | vital_articles |
Anthrax is an infection caused by the bacterium Bacillus anthracis or Bacillus cereus biovar anthracis. Infection typically occurs by contact with the skin, inhalation, or intestinal absorption. Symptom onset occurs between one day and more than two months after the infection is contracted. The skin form presents with ... | Anthrax | Wikipedia | 402 | 42898 | https://en.wikipedia.org/wiki/Anthrax | Biology and health sciences | Infectious disease | null | vital_articles |
A rare disease, human anthrax is most common in Africa and central and southern Asia. It also occurs more regularly in Southern Europe than elsewhere on the continent and is uncommon in Northern Europe and North America. Globally, at least 2,000 cases occur a year, with about two cases a year in the United States. Skin... | Anthrax | Wikipedia | 442 | 42898 | https://en.wikipedia.org/wiki/Anthrax | Biology and health sciences | Infectious disease | null | vital_articles |
Cutaneous anthrax, also known as hide-porter's disease, is when anthrax occurs on the skin. It is the most common (>90% of cases) and least dangerous form (low mortality with treatment, 23.7% mortality without). Cutaneous anthrax presents as a boil-like skin lesion that eventually forms an ulcer with a black center (es... | Anthrax | Wikipedia | 474 | 42898 | https://en.wikipedia.org/wiki/Anthrax | Biology and health sciences | Infectious disease | null | vital_articles |
Over the next day or so, shortness of breath, cough, and chest pain become more common, and complaints not involving the chest such as nausea, vomiting, altered mental status, sweats, and headache develop in one-third or more of people. Upper respiratory tract symptoms occur in only a quarter of people, and muscle pain... | Anthrax | Wikipedia | 311 | 42898 | https://en.wikipedia.org/wiki/Anthrax | Biology and health sciences | Infectious disease | null | vital_articles |
Bacillus anthracis is a rod-shaped, Gram-positive, facultative anaerobe bacterium about 1 by 9 μm in size. It was shown to cause disease by Robert Koch in 1876 when he took a blood sample from an infected cow, isolated the bacteria, and put them into a mouse. The bacterium normally rests in spore form in the soil, and ... | Anthrax | Wikipedia | 374 | 42898 | https://en.wikipedia.org/wiki/Anthrax | Biology and health sciences | Infectious disease | null | vital_articles |
The infection of herbivores (and occasionally humans) by inhalation normally begins with inhaled spores being transported through the air passages into the tiny air sacs (alveoli) in the lungs. The spores are then picked up by scavenger cells (macrophages) in the lungs and transported through small vessels (lymphatics)... | Anthrax | Wikipedia | 283 | 42898 | https://en.wikipedia.org/wiki/Anthrax | Biology and health sciences | Infectious disease | null | vital_articles |
Exposure and transmission
Anthrax can enter the human body through the intestines (gastrointestinal), lungs (pulmonary), or skin (cutaneous), and causes distinct clinical symptoms based on its site of entry. Anthrax does not usually spread from an infected human to an uninfected human. If the disease is fatal to the p... | Anthrax | Wikipedia | 444 | 42898 | https://en.wikipedia.org/wiki/Anthrax | Biology and health sciences | Infectious disease | null | vital_articles |
Mechanism
The lethality of the anthrax disease is due to the bacterium's two principal virulence factors: the poly-D-glutamic acid capsule, which protects the bacterium from phagocytosis by host neutrophils; and the tripartite protein toxin, called anthrax toxin, consisting of protective antigen (PA), edema factor (EF... | Anthrax | Wikipedia | 326 | 42898 | https://en.wikipedia.org/wiki/Anthrax | Biology and health sciences | Infectious disease | null | vital_articles |
Edema factor is a calmodulin-dependent adenylate cyclase. Adenylate cyclase catalyzes the conversion of ATP into cyclic AMP (cAMP) and pyrophosphate. The complexation of adenylate cyclase with calmodulin removes calmodulin from stimulating calcium-triggered signaling, thus inhibiting the immune response. To be specific... | Anthrax | Wikipedia | 387 | 42898 | https://en.wikipedia.org/wiki/Anthrax | Biology and health sciences | Infectious disease | null | vital_articles |
All Bacillus species grow well on 5% sheep blood agar and other routine culture media. Polymyxin-lysozyme-EDTA-thallous acetate can be used to isolate B. anthracis from contaminated specimens, and bicarbonate agar is used as an identification method to induce capsule formation. Bacillus spp. usually grow within 24 hour... | Anthrax | Wikipedia | 430 | 42898 | https://en.wikipedia.org/wiki/Anthrax | Biology and health sciences | Infectious disease | null | vital_articles |
Protective, impermeable clothing and equipment such as rubber gloves, rubber apron, and rubber boots with no perforations are used when handling the body. No skin, especially if it has any wounds or scratches, should be exposed. Disposable personal protective equipment is preferable, but if not available, decontaminati... | Anthrax | Wikipedia | 301 | 42898 | https://en.wikipedia.org/wiki/Anthrax | Biology and health sciences | Infectious disease | null | vital_articles |
Currently administered human anthrax vaccines include acellular subunit vaccine (United States) and live vaccine (Russia) varieties. All currently used anthrax vaccines show considerable local and general reactogenicity (erythema, induration, soreness, fever) and serious adverse reactions occur in about 1% of recipient... | Anthrax | Wikipedia | 386 | 42898 | https://en.wikipedia.org/wiki/Anthrax | Biology and health sciences | Infectious disease | null | vital_articles |
Anthrax cannot be spread from person to person, except in the rare case of skin exudates from cutaneous anthrax. However, a person's clothing and body may be contaminated with anthrax spores. Effective decontamination of people can be accomplished by a thorough wash-down with antimicrobial soap and water. Wastewater is... | Anthrax | Wikipedia | 512 | 42898 | https://en.wikipedia.org/wiki/Anthrax | Biology and health sciences | Infectious disease | null | vital_articles |
Biologic for Drug-, Antibody- or Vaccine-resistant Anthrax
Treatment of multi-drug resistant, antibody- or vaccine-resistant Anthrax is also possible. Legler, et al. showed that pegylated CapD (capsule depolymerase) could provide protection against 5 LD50 exposures to lethal Ames spores without the use of antibiotic... | Anthrax | Wikipedia | 336 | 42898 | https://en.wikipedia.org/wiki/Anthrax | Biology and health sciences | Infectious disease | null | vital_articles |
Animals
Anthrax, a bacterial disease caused by Bacillus anthracis, can have devastating effects on animals. It primarily affects herbivores such as cattle, sheep, and goats, but a wide range of mammals, birds, and even humans can also be susceptible. Infection typically occurs through the ingestion of spores in contam... | Anthrax | Wikipedia | 480 | 42898 | https://en.wikipedia.org/wiki/Anthrax | Biology and health sciences | Infectious disease | null | vital_articles |
In 2007 two cases of cutaneous anthrax were reported in Danbury, Connecticut. The case involved a maker of traditional African-style drums who was working with a goat hide purchased from a dealer in New York City which had been previously cleared by Customs. While the hide was being scraped, a spider bite led to the sp... | Anthrax | Wikipedia | 357 | 42898 | https://en.wikipedia.org/wiki/Anthrax | Biology and health sciences | Infectious disease | null | vital_articles |
Although Koch arguably made the greatest theoretical contribution to understanding anthrax, other researchers were more concerned with the practical questions of how to prevent the disease. In Britain, where anthrax affected workers in the wool, worsted, hides, and tanning industries, it was viewed with fear. John Henr... | Anthrax | Wikipedia | 432 | 42898 | https://en.wikipedia.org/wiki/Anthrax | Biology and health sciences | Infectious disease | null | vital_articles |
After this apparent triumph, which was widely reported in the local, national, and international press, Pasteur made strenuous efforts to export the vaccine beyond France. He used his celebrity status to establish Pasteur Institutes across Europe and Asia, and his nephew, Adrien Loir, travelled to Australia in 1888 to ... | Anthrax | Wikipedia | 497 | 42898 | https://en.wikipedia.org/wiki/Anthrax | Biology and health sciences | Infectious disease | null | vital_articles |
Site cleanup
Anthrax spores can survive for very long periods of time in the environment after release. Chemical methods for cleaning anthrax-contaminated sites or materials may use oxidizing agents such as peroxides, ethylene oxide, Sandia Foam, chlorine dioxide (used in the Hart Senate Office Building), peracetic ac... | Anthrax | Wikipedia | 500 | 42898 | https://en.wikipedia.org/wiki/Anthrax | Biology and health sciences | Infectious disease | null | vital_articles |
Cleanup of anthrax-contaminated areas on ranches and in the wild is much more problematic. Carcasses may be burned, though often 3 days are needed to burn a large carcass and this is not feasible in areas with little wood. Carcasses may also be buried, though the burying of large animals deeply enough to prevent resurf... | Anthrax | Wikipedia | 406 | 42898 | https://en.wikipedia.org/wiki/Anthrax | Biology and health sciences | Infectious disease | null | vital_articles |
In 1942, British scientists at Porton Down began research on Operation Vegetarian, an ultimately unused biowarfare military operation plan which called for animal feed pellets containing linseed infected with anthrax spores of the Vollum-14578 strain to be dropped by air over the countryside of Nazi Germany. The pellet... | Anthrax | Wikipedia | 352 | 42898 | https://en.wikipedia.org/wiki/Anthrax | Biology and health sciences | Infectious disease | null | vital_articles |
Despite signing the 1972 agreement to end bioweapon production, the government of the Soviet Union had an active bioweapons program that included the production of hundreds of tons of anthrax after this period. On 2 April 1979, some of the over one million people living in Sverdlovsk (now called Ekaterinburg, Russia), ... | Anthrax | Wikipedia | 338 | 42898 | https://en.wikipedia.org/wiki/Anthrax | Biology and health sciences | Infectious disease | null | vital_articles |
To support the cover-up story, Soviet medical and legal journals published articles about an outbreak in livestock that caused gastrointestinal anthrax in people having consumed infected meat, and cutaneous anthrax in people having come into contact with the animals. All medical and public health records were confiscat... | Anthrax | Wikipedia | 484 | 42898 | https://en.wikipedia.org/wiki/Anthrax | Biology and health sciences | Infectious disease | null | vital_articles |
A scientific experiment performed by a high school student, later published in the Journal of Medical Toxicology, suggested a domestic electric iron at its hottest setting (at least ) used for at least 5 minutes should destroy all anthrax spores in a common postal envelope.
Other animals
Anthrax is especially rare in... | Anthrax | Wikipedia | 195 | 42898 | https://en.wikipedia.org/wiki/Anthrax | Biology and health sciences | Infectious disease | null | vital_articles |
A photodiode is a semiconductor diode sensitive to photon radiation, such as visible light, infrared or ultraviolet radiation, X-rays and gamma rays. It produces an electrical current when it absorbs photons. This can be used for detection and measurement applications, or for the generation of electrical power in solar... | Photodiode | Wikipedia | 466 | 42937 | https://en.wikipedia.org/wiki/Photodiode | Technology | Components | null | vital_articles |
In photoconductive mode the diode is reverse biased, that is, with the cathode driven positive with respect to the anode. This reduces the response time because the additional reverse bias increases the width of the depletion layer, which decreases the junction's capacitance and increases the region with an electric f... | Photodiode | Wikipedia | 468 | 42937 | https://en.wikipedia.org/wiki/Photodiode | Technology | Components | null | vital_articles |
A solaristor is a two-terminal gate-less phototransistor. A compact class of two-terminal phototransistors or solaristors have been demonstrated in 2018 by ICN2 researchers. The novel concept is a two-in-one power source plus transistor device that runs on solar energy by exploiting a memresistive effect in the flow of... | Photodiode | Wikipedia | 402 | 42937 | https://en.wikipedia.org/wiki/Photodiode | Technology | Components | null | vital_articles |
Spectral responsivity The spectral responsivity is a ratio of the generated photocurrent to incident light power, expressed in A/W when used in photoconductive mode. The wavelength-dependence may also be expressed as a quantum efficiency or the ratio of the number of photogenerated carriers to incident photons which is... | Photodiode | Wikipedia | 391 | 42937 | https://en.wikipedia.org/wiki/Photodiode | Technology | Components | null | vital_articles |
Noise-equivalent power Noise-equivalent power (NEP) is the minimum input optical power to generate photocurrent, equal to the rms noise current in a 1 hertz bandwidth. NEP is essentially the minimum detectable power. The related characteristic detectivity () is the inverse of NEP (1/NEP) and the specific detectivity (... | Photodiode | Wikipedia | 168 | 42937 | https://en.wikipedia.org/wiki/Photodiode | Technology | Components | null | vital_articles |
When a photodiode is used in an optical communication system, all these parameters contribute to the sensitivity of the optical receiver which is the minimum input power required for the receiver to achieve a specified bit error rate.
Applications
P–n photodiodes are used in similar applications to other photodetector... | Photodiode | Wikipedia | 456 | 42937 | https://en.wikipedia.org/wiki/Photodiode | Technology | Components | null | vital_articles |
P–n photodiodes are not used to measure extremely low light intensities. Instead, if high sensitivity is needed, avalanche photodiodes, intensified charge-coupled devices or photomultiplier tubes are used for applications such as astronomy, spectroscopy, night vision equipment and laser rangefinding.
Comparison with p... | Photodiode | Wikipedia | 361 | 42937 | https://en.wikipedia.org/wiki/Photodiode | Technology | Components | null | vital_articles |
Early charge-coupled device image sensors suffered from shutter lag. This was largely explained with the re-invention of the pinned photodiode. It was developed by Nobukazu Teranishi, Hiromitsu Shiraki and Yasuo Ishihara at NEC in 1980. Sony in 1975 recognized that lag can be eliminated if the signal carriers could be... | Photodiode | Wikipedia | 457 | 42937 | https://en.wikipedia.org/wiki/Photodiode | Technology | Components | null | vital_articles |
Passive-pixel image sensor
The passive-pixel sensor (PPS) is a type of photodiode array. It was the precursor to the active-pixel sensor (APS). A passive-pixel sensor consists of passive pixels which are read out without amplification, with each pixel consisting of a photodiode and a MOSFET switch. In a photodiode arra... | Photodiode | Wikipedia | 178 | 42937 | https://en.wikipedia.org/wiki/Photodiode | Technology | Components | null | vital_articles |
An endospore is a dormant, tough, and non-reproductive structure produced by some bacteria in the phylum Bacillota. The name "endospore" is suggestive of a spore or seed-like form (endo means 'within'), but it is not a true spore (i.e., not an offspring). It is a stripped-down, dormant form to which the bacterium can r... | Endospore | Wikipedia | 370 | 42957 | https://en.wikipedia.org/wiki/Endospore | Biology and health sciences | Basic anatomy | Biology | vital_articles |
Endospores can survive without nutrients. They are resistant to ultraviolet radiation, desiccation, high temperature, extreme freezing and chemical disinfectants. Thermo-resistant endospores were first hypothesized by Ferdinand Cohn after studying Bacillus subtilis growth on cheese after boiling the cheese. His notion ... | Endospore | Wikipedia | 392 | 42957 | https://en.wikipedia.org/wiki/Endospore | Biology and health sciences | Basic anatomy | Biology | vital_articles |
Bacteria produce a single endospore internally. The spore is sometimes surrounded by a thin covering known as the exosporium, which overlies the spore coat. The spore coat, which acts like a sieve that excludes large toxic molecules like lysozyme, is resistant to many toxic molecules and may also contain enzymes that a... | Endospore | Wikipedia | 460 | 42957 | https://en.wikipedia.org/wiki/Endospore | Biology and health sciences | Basic anatomy | Biology | vital_articles |
Visualising endospores under light microscopy can be difficult due to the impermeability of the endospore wall to dyes and stains. While the rest of a bacterial cell may stain, the endospore is left colourless. To combat this, a special stain technique called a Moeller stain is used. That allows the endospore to show u... | Endospore | Wikipedia | 365 | 42957 | https://en.wikipedia.org/wiki/Endospore | Biology and health sciences | Basic anatomy | Biology | vital_articles |
When a bacterium detects environmental conditions are becoming unfavourable it may start the process of endosporulation, which takes about eight hours. The DNA is replicated and a membrane wall known as a spore septum begins to form between it and the rest of the cell. The plasma membrane of the cell surrounds this wal... | Endospore | Wikipedia | 492 | 42957 | https://en.wikipedia.org/wiki/Endospore | Biology and health sciences | Basic anatomy | Biology | vital_articles |
While significantly resistant to heat and radiation, endospores can be destroyed by burning or by autoclaving at a temperature exceeding the boiling point of water, 100 °C. Endospores are able to survive at 100 °C for hours, although the larger the number of hours the fewer that will survive. An indirect way to destroy... | Endospore | Wikipedia | 403 | 42957 | https://en.wikipedia.org/wiki/Endospore | Biology and health sciences | Basic anatomy | Biology | vital_articles |
Bacterial endospores are resistant to antibiotics, most disinfectants, and physical agents such as radiation, boiling, and drying. The impermeability of the spore coat is thought to be responsible for the endospore's resistance to chemicals. The heat resistance of endospores is due to a variety of factors:
Calcium dip... | Endospore | Wikipedia | 499 | 42957 | https://en.wikipedia.org/wiki/Endospore | Biology and health sciences | Basic anatomy | Biology | vital_articles |
Endospores can stay dormant for a very long time. For instance, endospores were found in the tombs of the Egyptian pharaohs. When placed in appropriate medium, under appropriate conditions, they were able to be reactivated. In 1995, Raul Cano of California Polytechnic State University found bacterial spores in the gut ... | Endospore | Wikipedia | 484 | 42957 | https://en.wikipedia.org/wiki/Endospore | Biology and health sciences | Basic anatomy | Biology | vital_articles |
Biotechnology
Bacillus subtilis spores are useful for the expression of recombinant proteins and in particular for the surface display of peptides and proteins as a tool for fundamental and applied research in the fields of microbiology, biotechnology and vaccination.
Endospore-forming bacteria
Examples of endospore-f... | Endospore | Wikipedia | 504 | 42957 | https://en.wikipedia.org/wiki/Endospore | Biology and health sciences | Basic anatomy | Biology | vital_articles |
Snell's law (also known as the Snell–Descartes law, the ibn-Sahl law, and the law of refraction) is a formula used to describe the relationship between the angles of incidence and refraction, when referring to light or other waves passing through a boundary between two different isotropic media, such as water, glass, ... | Snell's law | Wikipedia | 409 | 42964 | https://en.wikipedia.org/wiki/Snell%27s%20law | Physical sciences | Optics | Physics | vital_articles |
The law was rediscovered by Thomas Harriot in 1602, who however did not publish his results although he had corresponded with Kepler on this very subject. In 1621, the Dutch astronomer Willebrord Snellius (1580–1626)—Snell—derived a mathematically equivalent form, that remained unpublished during his lifetime. René Des... | Snell's law | Wikipedia | 430 | 42964 | https://en.wikipedia.org/wiki/Snell%27s%20law | Physical sciences | Optics | Physics | vital_articles |
According to Dijksterhuis, "In De natura lucis et proprietate (1662) Isaac Vossius said that Descartes had seen Snell's paper and concocted his own proof. We now know this charge to be undeserved but it has been adopted many times since." Both Fermat and Huygens repeated this accusation that Descartes had copied Snel... | Snell's law | Wikipedia | 481 | 42964 | https://en.wikipedia.org/wiki/Snell%27s%20law | Physical sciences | Optics | Physics | vital_articles |
Snell's law is generally true only for isotropic or specular media (such as glass). In anisotropic media such as some crystals, birefringence may split the refracted ray into two rays, the ordinary or o-ray which follows Snell's law, and the other extraordinary or e-ray which may not be co-planar with the incident ray.... | Snell's law | Wikipedia | 510 | 42964 | https://en.wikipedia.org/wiki/Snell%27s%20law | Physical sciences | Optics | Physics | vital_articles |
Derivation from conservation of energy and momentum
Yet another way to derive Snell's law is based on translation symmetry considerations. For example, a homogeneous surface perpendicular to the z direction cannot change the transverse momentum. Since the propagation vector is proportional to the photon's momentum, th... | Snell's law | Wikipedia | 415 | 42964 | https://en.wikipedia.org/wiki/Snell%27s%20law | Physical sciences | Optics | Physics | vital_articles |
When light travels from a medium with a higher refractive index to one with a lower refractive index, Snell's law seems to require in some cases (whenever the angle of incidence is large enough) that the sine of the angle of refraction be greater than one. This of course is impossible, and the light in such cases is co... | Snell's law | Wikipedia | 502 | 42964 | https://en.wikipedia.org/wiki/Snell%27s%20law | Physical sciences | Optics | Physics | vital_articles |
Opahs, also commonly known as moonfish, sunfish, cowfish (not to be confused with Molidae), kingfish, and redfin ocean pan are large, colorful, deep-bodied pelagic lampriform fishes comprising the small family Lampridae (also spelled Lamprididae).
The family comprises two genera: Lampris () and the monotypic Megalamp... | Opah | Wikipedia | 451 | 1490711 | https://en.wikipedia.org/wiki/Opah | Biology and health sciences | Acanthomorpha | Animals | vital_articles |
Extinct species
† Lampris zatima, also known as "Diatomœca zatima", is a very small, extinct species from the late Miocene of what is now Southern California known primarily from fragments, and the occasional headless specimens.
† Megalampris keyesi is an extinct species estimated to be about 4 m in length. Fossil re... | Opah | Wikipedia | 483 | 1490711 | https://en.wikipedia.org/wiki/Opah | Biology and health sciences | Acanthomorpha | Animals | vital_articles |
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