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Procedure
Given an array of elements with values or records sorted such that , and target value , the following subroutine uses binary search to find the index of in .
Set to and to .
If , the search terminates as unsuccessful.
Set (the position of the middle element) to the floor of , which is the greatest ... | Binary search | Wikipedia | 437 | 4266 | https://en.wikipedia.org/wiki/Binary%20search | Mathematics | Algorithms | null |
function binary_search_alternative(A, n, T) is
L := 0
R := n − 1
while L != R do
m := ceil((L + R) / 2)
if A[m] > T then
R := m − 1
else:
L := m
if A[L] = T then
return L
return unsuccessful
Duplicate elements
The procedure may ret... | Binary search | Wikipedia | 509 | 4266 | https://en.wikipedia.org/wiki/Binary%20search | Mathematics | Algorithms | null |
If and , then is the rightmost element that equals . Even if is not in the array, is the number of elements in the array that are greater than .
Where floor is the floor function, the pseudocode for this version is:
function binary_search_rightmost(A, n, T):
L := 0
R := n
while L < R:
m :... | Binary search | Wikipedia | 412 | 4266 | https://en.wikipedia.org/wiki/Binary%20search | Mathematics | Algorithms | null |
In terms of the number of comparisons, the performance of binary search can be analyzed by viewing the run of the procedure on a binary tree. The root node of the tree is the middle element of the array. The middle element of the lower half is the left child node of the root, and the middle element of the upper half is... | Binary search | Wikipedia | 372 | 4266 | https://en.wikipedia.org/wiki/Binary%20search | Mathematics | Algorithms | null |
In terms of iterations, no search algorithm that works only by comparing elements can exhibit better average and worst-case performance than binary search. The comparison tree representing binary search has the fewest levels possible as every level above the lowest level of the tree is filled completely. Otherwise, the... | Binary search | Wikipedia | 512 | 4266 | https://en.wikipedia.org/wiki/Binary%20search | Mathematics | Algorithms | null |
For example, in a 7-element array, the root requires one iteration, the two elements below the root require two iterations, and the four elements below require three iterations. In this case, the internal path length is:
The average number of iterations would be based on the equation for the average case. The sum for... | Binary search | Wikipedia | 359 | 4266 | https://en.wikipedia.org/wiki/Binary%20search | Mathematics | Algorithms | null |
Performance of alternative procedure
Each iteration of the binary search procedure defined above makes one or two comparisons, checking if the middle element is equal to the target in each iteration. Assuming that each element is equally likely to be searched, each iteration makes 1.5 comparisons on average. A variati... | Binary search | Wikipedia | 479 | 4266 | https://en.wikipedia.org/wiki/Binary%20search | Mathematics | Algorithms | null |
Binary search versus other schemes
Sorted arrays with binary search are a very inefficient solution when insertion and deletion operations are interleaved with retrieval, taking time for each such operation. In addition, sorted arrays can complicate memory use especially when elements are often inserted into the arra... | Binary search | Wikipedia | 433 | 4266 | https://en.wikipedia.org/wiki/Binary%20search | Mathematics | Algorithms | null |
However, binary search is usually more efficient for searching as binary search trees will most likely be imperfectly balanced, resulting in slightly worse performance than binary search. This even applies to balanced binary search trees, binary search trees that balance their own nodes, because they rarely produce the... | Binary search | Wikipedia | 501 | 4266 | https://en.wikipedia.org/wiki/Binary%20search | Mathematics | Algorithms | null |
Other data structures
There exist data structures that may improve on binary search in some cases for both searching and other operations available for sorted arrays. For example, searches, approximate matches, and the operations available to sorted arrays can be performed more efficiently than binary search on specia... | Binary search | Wikipedia | 451 | 4266 | https://en.wikipedia.org/wiki/Binary%20search | Mathematics | Algorithms | null |
Instead of calculating the midpoint, interpolation search estimates the position of the target value, taking into account the lowest and highest elements in the array as well as length of the array. It works on the basis that the midpoint is not the best guess in many cases. For example, if the target value is close to... | Binary search | Wikipedia | 309 | 4266 | https://en.wikipedia.org/wiki/Binary%20search | Mathematics | Algorithms | null |
Generalization to graphs
Binary search has been generalized to work on certain types of graphs, where the target value is stored in a vertex instead of an array element. Binary search trees are one such generalization—when a vertex (node) in the tree is queried, the algorithm either learns that the vertex is the targe... | Binary search | Wikipedia | 491 | 4266 | https://en.wikipedia.org/wiki/Binary%20search | Mathematics | Algorithms | null |
History
The idea of sorting a list of items to allow for faster searching dates back to antiquity. The earliest known example was the Inakibit-Anu tablet from Babylon dating back to . The tablet contained about 500 sexagesimal numbers and their reciprocals sorted in lexicographical order, which made searching for a sp... | Binary search | Wikipedia | 442 | 4266 | https://en.wikipedia.org/wiki/Binary%20search | Mathematics | Algorithms | null |
In a practical implementation, the variables used to represent the indices will often be of fixed size (integers), and this can result in an arithmetic overflow for very large arrays. If the midpoint of the span is calculated as , then the value of may exceed the range of integers of the data type used to store the mi... | Binary search | Wikipedia | 208 | 4266 | https://en.wikipedia.org/wiki/Binary%20search | Mathematics | Algorithms | null |
C provides the function bsearch() in its standard library, which is typically implemented via binary search, although the official standard does not require it so.
C++'s standard library provides the functions binary_search(), lower_bound(), upper_bound() and equal_range().
D's standard library Phobos, in std.range m... | Binary search | Wikipedia | 418 | 4266 | https://en.wikipedia.org/wiki/Binary%20search | Mathematics | Algorithms | null |
A base pair (bp) is a fundamental unit of double-stranded nucleic acids consisting of two nucleobases bound to each other by hydrogen bonds. They form the building blocks of the DNA double helix and contribute to the folded structure of both DNA and RNA. Dictated by specific hydrogen bonding patterns, "Watson–Crick" (... | Base pair | Wikipedia | 383 | 4292 | https://en.wikipedia.org/wiki/Base%20pair | Biology and health sciences | Nucleic acids | Biology |
The size of an individual gene or an organism's entire genome is often measured in base pairs because DNA is usually double-stranded. Hence, the number of total base pairs is equal to the number of nucleotides in one of the strands (with the exception of non-coding single-stranded regions of telomeres). The haploid hum... | Base pair | Wikipedia | 390 | 4292 | https://en.wikipedia.org/wiki/Base%20pair | Biology and health sciences | Nucleic acids | Biology |
The bigger nucleobases, adenine and guanine, are members of a class of double-ringed chemical structures called purines; the smaller nucleobases, cytosine and thymine (and uracil), are members of a class of single-ringed chemical structures called pyrimidines. Purines are complementary only with pyrimidines: pyrimidine... | Base pair | Wikipedia | 480 | 4292 | https://en.wikipedia.org/wiki/Base%20pair | Biology and health sciences | Nucleic acids | Biology |
Chemical analogs of nucleotides can take the place of proper nucleotides and establish non-canonical base-pairing, leading to errors (mostly point mutations) in DNA replication and DNA transcription. This is due to their isosteric chemistry. One common mutagenic base analog is 5-bromouracil, which resembles thymine but... | Base pair | Wikipedia | 459 | 4292 | https://en.wikipedia.org/wiki/Base%20pair | Biology and health sciences | Nucleic acids | Biology |
For single-stranded DNA/RNA, units of nucleotides are used—abbreviated nt (or knt, Mnt, Gnt)—as they are not paired.
To distinguish between units of computer storage and bases, kbp, Mbp, Gbp, etc. may be used for base pairs.
The centimorgan is also often used to imply distance along a chromosome, but the number of bas... | Base pair | Wikipedia | 358 | 4292 | https://en.wikipedia.org/wiki/Base%20pair | Biology and health sciences | Nucleic acids | Biology |
In 2002, Ichiro Hirao's group in Japan developed an unnatural base pair between 2-amino-8-(2-thienyl)purine (s) and pyridine-2-one (y) that functions in transcription and translation, for the site-specific incorporation of non-standard amino acids into proteins. In 2006, they created 7-(2-thienyl)imidazo[4,5-b]pyridine... | Base pair | Wikipedia | 470 | 4292 | https://en.wikipedia.org/wiki/Base%20pair | Biology and health sciences | Nucleic acids | Biology |
In 2014 the same team from the Scripps Research Institute reported that they synthesized a stretch of circular DNA known as a plasmid containing natural T-A and C-G base pairs along with the best-performing UBP Romesberg's laboratory had designed and inserted it into cells of the common bacterium E. coli that successfu... | Base pair | Wikipedia | 481 | 4292 | https://en.wikipedia.org/wiki/Base%20pair | Biology and health sciences | Nucleic acids | Biology |
Additionally, Hoogsteen base pairing (typically written as A•U/T and G•C) can exist in some DNA sequences (e.g. CA and TA dinucleotides) in dynamic equilibrium with standard Watson–Crick pairing. They have also been observed in some protein–DNA complexes.
In addition to these alternative base pairings, a wide range of... | Base pair | Wikipedia | 116 | 4292 | https://en.wikipedia.org/wiki/Base%20pair | Biology and health sciences | Nucleic acids | Biology |
In computer science, a binary search tree (BST), also called an ordered or sorted binary tree, is a rooted binary tree data structure with the key of each internal node being greater than all the keys in the respective node's left subtree and less than the ones in its right subtree. The time complexity of operations on... | Binary search tree | Wikipedia | 490 | 4320 | https://en.wikipedia.org/wiki/Binary%20search%20tree | Mathematics | Data structures and types | null |
The time complexities of a binary search tree increases boundlessly with the tree height if the nodes are inserted in an arbitrary order, therefore self-balancing binary search trees were introduced to bound the height of the tree to . Various height-balanced binary search trees were introduced to confine the tree heig... | Binary search tree | Wikipedia | 500 | 4320 | https://en.wikipedia.org/wiki/Binary%20search%20tree | Mathematics | Data structures and types | null |
Iterative search
The recursive version of the search can be "unrolled" into a while loop. On most machines, the iterative version is found to be more efficient.
Since the search may proceed till some leaf node, the running time complexity of BST search is where is the height of the tree. However, the worst case for ... | Binary search tree | Wikipedia | 406 | 4320 | https://en.wikipedia.org/wiki/Binary%20search%20tree | Mathematics | Data structures and types | null |
The deletion of a node, say , from the binary search tree has three cases:
If is a leaf node, the parent node of gets replaced by and consequently is removed from the , as shown in (a).
If has only one child, the child node of gets elevated by modifying the parent node of to point to the child node, consequen... | Binary search tree | Wikipedia | 419 | 4320 | https://en.wikipedia.org/wiki/Binary%20search%20tree | Mathematics | Data structures and types | null |
Without rebalancing, insertions or deletions in a binary search tree may lead to degeneration, resulting in a height of the tree (where is number of items in a tree), so that the lookup performance is deteriorated to that of a linear search. Keeping the search tree balanced and height bounded by is a key to the usef... | Binary search tree | Wikipedia | 507 | 4320 | https://en.wikipedia.org/wiki/Binary%20search%20tree | Mathematics | Data structures and types | null |
A boomerang () is a thrown tool typically constructed with airfoil sections and designed to spin about an axis perpendicular to the direction of its flight. A returning boomerang is designed to return to the thrower, while a non-returning boomerang is designed as a weapon to be thrown straight. Various forms of Boomera... | Boomerang | Wikipedia | 263 | 4359 | https://en.wikipedia.org/wiki/Boomerang | Technology | Projectile weapons | null |
Returning boomerangs fly, and are examples of the earliest heavier-than-air human-made flight. A returning boomerang has two or more aerofoil section wings arranged so that when spinning they create unbalanced aerodynamic forces that curve its path into an ellipse, returning to its point of origin when thrown correctly... | Boomerang | Wikipedia | 510 | 4359 | https://en.wikipedia.org/wiki/Boomerang | Technology | Projectile weapons | null |
Boomerangs were, historically, used as hunting weapons, percussive musical instruments, battle clubs, fire-starters, decoys for hunting waterfowl, and as recreational play toys. The smallest boomerang may be less than from tip to tip, and the largest over in length. Tribal boomerangs may be inscribed or painted with... | Boomerang | Wikipedia | 469 | 4359 | https://en.wikipedia.org/wiki/Boomerang | Technology | Projectile weapons | null |
No one knows for sure how the returning boomerang was invented, but some modern boomerang makers speculate that it developed from the flattened throwing stick, still used by Aboriginal Australians and other indigenous peoples around the world, including the Navajo in North America. A hunting boomerang is delicately bal... | Boomerang | Wikipedia | 466 | 4359 | https://en.wikipedia.org/wiki/Boomerang | Technology | Projectile weapons | null |
Today, boomerangs are mostly used for recreation. There are different types of throwing contests: accuracy of return; Aussie round; trick catch; maximum time aloft; fast catch; and endurance (see below). The modern sport boomerang (often referred to as a 'boom' or 'rang') is made of Finnish birch plywood, hardwood, pla... | Boomerang | Wikipedia | 496 | 4359 | https://en.wikipedia.org/wiki/Boomerang | Technology | Projectile weapons | null |
Boomerangs can be made for right- or left-handed throwers. The difference between right and left is subtle, the planform is the same but the leading edges of the aerofoil sections are reversed. A right-handed boomerang makes a counter-clockwise, circular flight to the left while a left-handed boomerang flies clockwise ... | Boomerang | Wikipedia | 501 | 4359 | https://en.wikipedia.org/wiki/Boomerang | Technology | Projectile weapons | null |
Throwing technique
Boomerangs are generally thrown in unobstructed, open spaces at least twice as large as the range of the boomerang. The flight direction to the left or right depends upon the design of the boomerang itself, not the thrower. A right-handed or left-handed boomerang can be thrown with either hand, but t... | Boomerang | Wikipedia | 453 | 4359 | https://en.wikipedia.org/wiki/Boomerang | Technology | Projectile weapons | null |
The boomerang is aimed to the right of the oncoming wind; the exact angle depends on the strength of the wind and the boomerang itself. Left-handed boomerangs are thrown to the left of the wind and will fly a clockwise flight path. The trajectory is either parallel to the ground or slightly upwards. The boomerang can r... | Boomerang | Wikipedia | 442 | 4359 | https://en.wikipedia.org/wiki/Boomerang | Technology | Projectile weapons | null |
Aussie Round: considered by many to be the ultimate test of boomeranging skills. The boomerang should ideally cross the circle and come right back to the centre. Each thrower has five attempts. Points are awarded for distance, accuracy and the catch.
Accuracy: points are awarded according to how close the boomerang l... | Boomerang | Wikipedia | 509 | 4359 | https://en.wikipedia.org/wiki/Boomerang | Technology | Projectile weapons | null |
Long-distance versions
Long-distance boomerang throwers aim to have the boomerang go the furthest possible distance while returning close to the throwing point. In competition the boomerang must intersect an imaginary surface defined as an infinite vertical projection of a line centred on the thrower. Outside of comp... | Boomerang | Wikipedia | 373 | 4359 | https://en.wikipedia.org/wiki/Boomerang | Technology | Projectile weapons | null |
From theoretical point of view, distance boomerangs are interesting also for the following reason: for achieving a different behaviour during different flight phases, the ratio of the rotation frequency to the forward velocity has a U-shaped function, i.e., its derivative crosses 0. Practically, it means that the boome... | Boomerang | Wikipedia | 391 | 4359 | https://en.wikipedia.org/wiki/Boomerang | Technology | Projectile weapons | null |
"Aboriginalia", including the boomerang, as symbols of Australia dates from the late 1940s and early 1950s and was in widespread use by a largely European arts, crafts and design community. By the 1960s, the Australian tourism industry extended it to the very branding of Australia, particularly to overseas and domestic... | Boomerang | Wikipedia | 213 | 4359 | https://en.wikipedia.org/wiki/Boomerang | Technology | Projectile weapons | null |
Biological warfare, also known as germ warfare, is the use of biological toxins or infectious agents such as bacteria, viruses, insects, and fungi with the intent to kill, harm or incapacitate humans, animals or plants as an act of war. Biological weapons (often termed "bio-weapons", "biological threat agents", or "bio... | Biological warfare | Wikipedia | 491 | 4361 | https://en.wikipedia.org/wiki/Biological%20warfare | Technology | Weapons of mass destruction | null |
A nation or group that can pose a credible threat of mass casualty has the ability to alter the terms under which other nations or groups interact with it. When indexed to weapon mass and cost of development and storage, biological weapons possess destructive potential and loss of life far in excess of nuclear, chemica... | Biological warfare | Wikipedia | 338 | 4361 | https://en.wikipedia.org/wiki/Biological%20warfare | Technology | Weapons of mass destruction | null |
Rudimentary forms of biological warfare have been practiced since antiquity. The earliest documented incident of the intention to use biological weapons is recorded in Hittite texts of 1500–1200 BCE, in which victims of an unknown plague (possibly tularemia) were driven into enemy lands, causing an epidemic. The Assyr... | Biological warfare | Wikipedia | 283 | 4361 | https://en.wikipedia.org/wiki/Biological%20warfare | Technology | Weapons of mass destruction | null |
During the French and Indian War, in June 1763 a group of Native Americans laid siege to British-held Fort Pitt. Following instructions of his superior, Colonel Henry Bouquet, the commander of Fort Pitt, Swiss-born Captain Simeon Ecuyer, ordered his men to take smallpox-infested blankets from the infirmary and give it ... | Biological warfare | Wikipedia | 404 | 4361 | https://en.wikipedia.org/wiki/Biological%20warfare | Technology | Weapons of mass destruction | null |
World War II
With the onset of World War II, the Ministry of Supply in the United Kingdom established a biological warfare program at Porton Down, headed by the microbiologist Paul Fildes. The research was championed by Winston Churchill and soon tularemia, anthrax, brucellosis, and botulism toxins had been effectively... | Biological warfare | Wikipedia | 473 | 4361 | https://en.wikipedia.org/wiki/Biological%20warfare | Technology | Weapons of mass destruction | null |
During the final months of World War II, Japan planned to use plague as a biological weapon against U.S. civilians in San Diego, California, during Operation Cherry Blossoms at Night. The plan was set to launch on 22 September 1945, but it was not executed because of Japan's surrender on 15 August 1945.
Cold War
In Br... | Biological warfare | Wikipedia | 509 | 4361 | https://en.wikipedia.org/wiki/Biological%20warfare | Technology | Weapons of mass destruction | null |
The 1972 Biological Weapons Convention (BWC) supplements the Geneva Protocol by prohibiting the development, production, acquisition, transfer, stockpiling and use of biological weapons. Having entered into force on 26 March 1975, the BWC was the first multilateral disarmament treaty to ban the production of an entire ... | Biological warfare | Wikipedia | 405 | 4361 | https://en.wikipedia.org/wiki/Biological%20warfare | Technology | Weapons of mass destruction | null |
A technique called Clustered, Regularly Interspaced, Short Palindromic Repeat (CRISPR-Cas9) is now so cheap and widely available that scientists fear that amateurs will start experimenting with them. In this technique, a DNA sequence is cut off and replaced with a new sequence, e.g. one that codes for a particular prot... | Biological warfare | Wikipedia | 347 | 4361 | https://en.wikipedia.org/wiki/Biological%20warfare | Technology | Weapons of mass destruction | null |
Entomological warfare (EW) is a type of biological warfare that uses insects to attack the enemy. The concept has existed for centuries and research and development have continued into the modern era. EW has been used in battle by Japan and several other nations have developed and been accused of using an entomological... | Biological warfare | Wikipedia | 446 | 4361 | https://en.wikipedia.org/wiki/Biological%20warfare | Technology | Weapons of mass destruction | null |
Ideal characteristics of a biological agent to be used as a weapon against humans are high infectivity, high virulence, non-availability of vaccines and availability of an effective and efficient delivery system. Stability of the weaponized agent (the ability of the agent to retain its infectivity and virulence after a... | Biological warfare | Wikipedia | 472 | 4361 | https://en.wikipedia.org/wiki/Biological%20warfare | Technology | Weapons of mass destruction | null |
Toxins that can be used as weapons include ricin, staphylococcal enterotoxin B, botulinum toxin, saxitoxin, and many mycotoxins. These toxins and the organisms that produce them are sometimes referred to as select agents. In the United States, their possession, use, and transfer are regulated by the Centers for Disease... | Biological warfare | Wikipedia | 428 | 4361 | https://en.wikipedia.org/wiki/Biological%20warfare | Technology | Weapons of mass destruction | null |
Biological warfare can also specifically target plants to destroy crops or defoliate vegetation. The United States and Britain discovered plant growth regulators (i.e., herbicides) during the Second World War, which were then used by the UK in the counterinsurgency operations of the Malayan Emergency. Inspired by the u... | Biological warfare | Wikipedia | 466 | 4361 | https://en.wikipedia.org/wiki/Biological%20warfare | Technology | Weapons of mass destruction | null |
Many countries require their active-duty military personnel to get vaccinated for certain diseases that may potentially be used as a bioweapon such as anthrax, smallpox, and various other vaccines depending on the Area of Operations of the individual military units and commands.
Public health and disease surveillance
... | Biological warfare | Wikipedia | 462 | 4361 | https://en.wikipedia.org/wiki/Biological%20warfare | Technology | Weapons of mass destruction | null |
Single cause of a certain disease caused by an uncommon agent, with lack of an epidemiological explanation.
Unusual, rare, genetically engineered strain of an agent.
High morbidity and mortality rates in regards to patients with the same or similar symptoms.
Unusual presentation of the disease.
Unusual geographic or se... | Biological warfare | Wikipedia | 435 | 4361 | https://en.wikipedia.org/wiki/Biological%20warfare | Technology | Weapons of mass destruction | null |
The growing threat of biowarfare agents and bioterrorism has led to the development of specific field tools that perform on-the-spot analysis and identification of encountered suspect materials. One such technology, being developed by researchers from the Lawrence Livermore National Laboratory (LLNL), employs a "sandwi... | Biological warfare | Wikipedia | 372 | 4361 | https://en.wikipedia.org/wiki/Biological%20warfare | Technology | Weapons of mass destruction | null |
Biopreparat (18 labs and production centers)
Stepnogorsk Scientific and Technical Institute for Microbiology, Stepnogorsk, northern Kazakhstan
Institute of Ultra Pure Biochemical Preparations, Leningrad, a weaponized plague center
Vector State Research Center of Virology and Biotechnology (VECTOR), a weaponized smal... | Biological warfare | Wikipedia | 490 | 4361 | https://en.wikipedia.org/wiki/Biological%20warfare | Technology | Weapons of mass destruction | null |
Bioterrorism is terrorism involving the intentional release or dissemination of biological agents. These agents include bacteria, viruses, insects, fungi, and/or their toxins, and may be in a naturally occurring or a human-modified form, in much the same way as in biological warfare. Further, modern agribusiness is vul... | Bioterrorism | Wikipedia | 467 | 4393 | https://en.wikipedia.org/wiki/Bioterrorism | Technology | Biotechnology | null |
Shortly after the start of World War I, Germany launched a biological sabotage campaign in the United States, Russia, Romania, and France. At that time, Anton Dilger lived in Germany, but in 1915 he was sent to the United States carrying cultures of glanders, a virulent disease of horses and mules. Dilger set up a labo... | Bioterrorism | Wikipedia | 420 | 4393 | https://en.wikipedia.org/wiki/Bioterrorism | Technology | Biotechnology | null |
In 1980, the World Health Organization (WHO) announced the eradication of smallpox, a highly contagious and incurable disease. Although the disease has been eliminated in the wild, frozen stocks of smallpox virus are still maintained by the governments of the United States and Russia. Disastrous consequences are feared... | Bioterrorism | Wikipedia | 382 | 4393 | https://en.wikipedia.org/wiki/Bioterrorism | Technology | Biotechnology | null |
Scenarios
There are multiple considerable scenarios, how terrorists might employ biological agents. In 2000, tests conducted by various US agencies showed that indoor attacks in densely populated spaces are much more serious than outdoor attacks. Such enclosed spaces are large buildings, trains, indoor arenas, theaters... | Bioterrorism | Wikipedia | 499 | 4393 | https://en.wikipedia.org/wiki/Bioterrorism | Technology | Biotechnology | null |
Category A
These high-priority agents pose a risk to national security, can be easily transmitted and disseminated, result in high mortality, have potential major public health impact, may cause public panic, or require special action for public health preparedness. | Bioterrorism | Wikipedia | 50 | 4393 | https://en.wikipedia.org/wiki/Bioterrorism | Technology | Biotechnology | null |
SARS and COVID-19, though not as lethal as other diseases, was concerning to scientists and policymakers for its social and economic disruption potential. After the global containment of the pandemic, the United States President George W. Bush stated "...A global influenza pandemic that infects millions and lasts from ... | Bioterrorism | Wikipedia | 262 | 4393 | https://en.wikipedia.org/wiki/Bioterrorism | Technology | Biotechnology | null |
Anthrax: Anthrax is a non-contagious disease caused by the spore-forming bacterium Bacillus anthracis. The ability of Anthrax to produce within small spores, or bacilli bacterium, makes it readily permeable to porous skin and can cause abrupt symptoms within 24 hours of exposure. The dispersal of this pathogen among de... | Bioterrorism | Wikipedia | 400 | 4393 | https://en.wikipedia.org/wiki/Bioterrorism | Technology | Biotechnology | null |
Smallpox: Smallpox is a highly contagious virus. It is transmitted easily through the atmosphere and has a high mortality rate (20–40%). Smallpox was eradicated in the world in the 1970s, thanks to a worldwide vaccination program. However, some virus samples are still available in Russian and American laboratories. Som... | Bioterrorism | Wikipedia | 408 | 4393 | https://en.wikipedia.org/wiki/Bioterrorism | Technology | Biotechnology | null |
Viral hemorrhagic fevers: This includes hemorrhagic fevers caused by members of the family Filoviridae (Marburg virus and Ebola virus), and by the family Arenaviridae (for example Lassa virus and Machupo virus). Ebola virus disease, in particular, has caused high fatality rates ranging from 25 to 90% with a 50% average... | Bioterrorism | Wikipedia | 207 | 4393 | https://en.wikipedia.org/wiki/Bioterrorism | Technology | Biotechnology | null |
Category B
Category B agents are moderately easy to disseminate and have low mortality rates.
Brucellosis (Brucella species)
Epsilon toxin of Clostridium perfringens
Food safety threats (for example, Salmonella species, E coli O157:H7, Shigella, Staphylococcus aureus)
Glanders (Burkholderia mallei)
Melioidosis (B... | Bioterrorism | Wikipedia | 425 | 4393 | https://en.wikipedia.org/wiki/Bioterrorism | Technology | Biotechnology | null |
Preparedness
Export controls on biological agents are not applied uniformly, providing terrorists a route for acquisition. Laboratories are working on advanced detection systems to provide early warning, identify contaminated areas and populations at risk, and to facilitate prompt treatment. Methods for predicting the... | Bioterrorism | Wikipedia | 167 | 4393 | https://en.wikipedia.org/wiki/Bioterrorism | Technology | Biotechnology | null |
Aspects of protection against bioterrorism in the United States include:
Detection and resilience strategies in combating bioterrorism. This occurs primarily through the efforts of the Office of Health Affairs (OHA), a part of the Department of Homeland Security (DHS), whose role is to prepare for an emergency situatio... | Bioterrorism | Wikipedia | 401 | 4393 | https://en.wikipedia.org/wiki/Bioterrorism | Technology | Biotechnology | null |
Enhanced equipment for first responders. One recent advancement is the commercialization of a new form of Tyvex™ armor which protects first responders and patients from chemical and biological contaminants. There has also been a new generation of Self-Contained Breathing Apparatuses (SCBA) which has been recently made ... | Bioterrorism | Wikipedia | 146 | 4393 | https://en.wikipedia.org/wiki/Bioterrorism | Technology | Biotechnology | null |
Excelsior Challenge. In the second week of September 2016, the state of New York held a large emergency response training exercise called the Excelsior Challenge, with over 100 emergency responders participating. According to WKTV, "This is the fourth year of the Excelsior Challenge, a training exercise designed for po... | Bioterrorism | Wikipedia | 373 | 4393 | https://en.wikipedia.org/wiki/Bioterrorism | Technology | Biotechnology | null |
Project BioShield. The accrual of vaccines and treatments for potential biological threats, also known as medical countermeasures has been an important aspect in preparing for a potential bioterrorist attack; this took the form of a program beginning in 2004, referred to as Project BioShield. The significance of this p... | Bioterrorism | Wikipedia | 190 | 4393 | https://en.wikipedia.org/wiki/Bioterrorism | Technology | Biotechnology | null |
On a CNN news broadcast in 2011, the CNN chief medical correspondent, Dr. Sanjay Gupta, weighed in on the American government's recent approach to bioterrorist threats. He explains how, even though the United States would be better fending off bioterrorist attacks now than they would be a decade ago, the amount of mone... | Bioterrorism | Wikipedia | 469 | 4393 | https://en.wikipedia.org/wiki/Bioterrorism | Technology | Biotechnology | null |
Gerstein formerly served in the Science and Technology Directorate of the Department of Homeland Security from 2011 to 2014. He claims there has not been a serious plan of action since 2004 during George W. Bush's presidency, in which he issued a Homeland Security directive delegating responsibilities among various fed... | Bioterrorism | Wikipedia | 259 | 4393 | https://en.wikipedia.org/wiki/Bioterrorism | Technology | Biotechnology | null |
Bill Gates said in a February 18, 2017 Business Insider op-ed (published near the time of his Munich Security Conference speech) that it is possible for an airborne pathogen to kill at least 30 million people over the course of a year. In a New York Times report, the Gates Foundation predicted that a modern outbreak si... | Bioterrorism | Wikipedia | 266 | 4393 | https://en.wikipedia.org/wiki/Bioterrorism | Technology | Biotechnology | null |
Also, novel approaches in biotechnology, such as synthetic biology, could be used in the future to design new types of biological warfare agents. Special attention has to be laid on future experiments (of concern) that:
Would demonstrate how to render a vaccine ineffective;
Would confer resistance to therapeutically ... | Bioterrorism | Wikipedia | 455 | 4393 | https://en.wikipedia.org/wiki/Bioterrorism | Technology | Biotechnology | null |
On February 5, 2002, George W. Bush visited the RODS laboratory and used it as a model for a $300 million spending proposal to equip all 50 states with biosurveillance systems. In a speech delivered at the nearby Masonic temple, Bush compared the RODS system to a modern "DEW" line (referring to the Cold War ballistic m... | Bioterrorism | Wikipedia | 498 | 4393 | https://en.wikipedia.org/wiki/Bioterrorism | Technology | Biotechnology | null |
Another powerful tool developed within New York City for use in countering bioterrorism is the development of the New York City Syndromic Surveillance System. This system is essentially a way of tracking disease progression throughout New York City, and was developed by the New York City Department of Health and Mental... | Bioterrorism | Wikipedia | 401 | 4393 | https://en.wikipedia.org/wiki/Bioterrorism | Technology | Biotechnology | null |
Media attention toward the seriousness of biological attacks increased in 2013 to 2014. In July 2013, Forbes published an article with the title "Bioterrorism: A Dirty Little Threat With Huge Potential Consequences." In November 2013, Fox News reported on a new strain of botulism, saying that the Centers for Disease an... | Bioterrorism | Wikipedia | 416 | 4393 | https://en.wikipedia.org/wiki/Bioterrorism | Technology | Biotechnology | null |
For example:
The Office of Public Health Preparedness and Response would be cut by $136 million, or 9.7 percent. The office tracks outbreaks of disease.
The National Center for Emerging and Zoonotic Infectious Diseases would be cut by $65 million, or 11 percent. The center is a branch of the Centers for Disease Contr... | Bioterrorism | Wikipedia | 371 | 4393 | https://en.wikipedia.org/wiki/Bioterrorism | Technology | Biotechnology | null |
The Northrop B-2 Spirit, also known as the Stealth Bomber, is an American heavy strategic bomber, featuring low-observable stealth technology designed to penetrate dense anti-aircraft defenses. A subsonic flying wing with a crew of two, the plane was designed by Northrop (later Northrop Grumman) as the prime contractor... | Northrop B-2 Spirit | Wikipedia | 463 | 4396 | https://en.wikipedia.org/wiki/Northrop%20B-2%20Spirit | Technology | Specific aircraft | null |
The United States Air Force has nineteen B-2s in service as of 2024; one was destroyed in a 2008 crash and another one damaged in a crash in 2022 was retired from service likely on account of the cost and duration of a potential repair. The Air Force plans to operate the B-2s until 2032, when the Northrop Grumman B-21 ... | Northrop B-2 Spirit | Wikipedia | 379 | 4396 | https://en.wikipedia.org/wiki/Northrop%20B-2%20Spirit | Technology | Specific aircraft | null |
Plans were well advanced by the summer of 1975, when DARPA started the Experimental Survivability Testbed project. Northrop and Lockheed were awarded contracts in the first round of testing. Lockheed received the sole award for the second test round in April 1976 leading to the Have Blue program and eventually the F-11... | Northrop B-2 Spirit | Wikipedia | 458 | 4396 | https://en.wikipedia.org/wiki/Northrop%20B-2%20Spirit | Technology | Specific aircraft | null |
The Northrop team's ATB design was selected over the Lockheed/Rockwell design on 20 October 1981. The Northrop design received the designation B-2 and the name "Spirit". The bomber's design was changed in the mid-1980s when the mission profile was changed from high-altitude to low-altitude, terrain-following. The redes... | Northrop B-2 Spirit | Wikipedia | 435 | 4396 | https://en.wikipedia.org/wiki/Northrop%20B-2%20Spirit | Technology | Specific aircraft | null |
The B-2 was first publicly displayed on 22 November 1988 at United States Air Force Plant 42 in Palmdale, California, where it was assembled. This viewing was heavily restricted, and guests were not allowed to see the rear of the B-2. However, Aviation Week editors found that there were no airspace restrictions above t... | Northrop B-2 Spirit | Wikipedia | 374 | 4396 | https://en.wikipedia.org/wiki/Northrop%20B-2%20Spirit | Technology | Specific aircraft | null |
The program was the subject of public controversy for its cost to American taxpayers. In 1996, the GAO disclosed that the USAF's B-2 bombers "will be, by far, the costliest bombers to operate on a per aircraft basis", costing over three times as much as the B-1B (US$9.6 million annually) and over four times as much as ... | Northrop B-2 Spirit | Wikipedia | 506 | 4396 | https://en.wikipedia.org/wiki/Northrop%20B-2%20Spirit | Technology | Specific aircraft | null |
Opposition
In its consideration of the fiscal year 1990 defense budget, the House Armed Services Committee trimmed $800 million from the B-2 research and development budget, while at the same time staving off a motion to end the project. Opposition in committee and in Congress was mostly broad and bipartisan, with Cong... | Northrop B-2 Spirit | Wikipedia | 452 | 4396 | https://en.wikipedia.org/wiki/Northrop%20B-2%20Spirit | Technology | Specific aircraft | null |
Some B-2 advocates argued that procuring twenty additional aircraft would save money because B-2s would be able to deeply penetrate anti-aircraft defenses and use low-cost, short-range attack weapons rather than expensive standoff weapons. However, in 1995, the Congressional Budget Office (CBO) and its Director of Nati... | Northrop B-2 Spirit | Wikipedia | 457 | 4396 | https://en.wikipedia.org/wiki/Northrop%20B-2%20Spirit | Technology | Specific aircraft | null |
In July 2010, political analyst Rebecca Grant speculated that when the B-2 becomes unable to reliably penetrate enemy defenses, the Lockheed Martin F-35 Lightning II may take on its strike/interdiction mission, carrying B61 nuclear bombs as a tactical bomber. However, in March 2012, The Pentagon announced that a $2 bil... | Northrop B-2 Spirit | Wikipedia | 505 | 4396 | https://en.wikipedia.org/wiki/Northrop%20B-2%20Spirit | Technology | Specific aircraft | null |
Although the USAF previously planned to operate the B-2 until 2058, the FY 2019 budget moved up its retirement to "no later than 2032". It also moved the retirement of the B-1 to 2036 while extending the B-52's service life into the 2050s, because the B-52 has lower maintenance costs, versatile conventional payload, an... | Northrop B-2 Spirit | Wikipedia | 410 | 4396 | https://en.wikipedia.org/wiki/Northrop%20B-2%20Spirit | Technology | Specific aircraft | null |
Approximately 80 pilots fly the B-2. Each aircraft has a crew of two, a pilot in the left seat and mission commander in the right, and has provisions for a third crew member if needed. For comparison, the B-1B has a crew of four and the B-52 has a crew of five. The B-2 is highly automated, and one crew member can sleep... | Northrop B-2 Spirit | Wikipedia | 399 | 4396 | https://en.wikipedia.org/wiki/Northrop%20B-2%20Spirit | Technology | Specific aircraft | null |
The B-2 has various conventional weapons in its arsenal, including Mark 82 and Mark 84 bombs, CBU-87 Combined Effects Munitions, GATOR mines, and the CBU-97 Sensor Fuzed Weapon. In July 2009, Northrop Grumman reported the B-2 was compatible with the equipment necessary to deploy the Massive Ordnance Penetrator (MOP), ... | Northrop B-2 Spirit | Wikipedia | 389 | 4396 | https://en.wikipedia.org/wiki/Northrop%20B-2%20Spirit | Technology | Specific aircraft | null |
For safety and fault-detection purposes, an on-board test system is linked with the majority of avionics on the B-2 to continuously monitor the performance and status of thousands of components and consumables; it also provides post-mission servicing instructions for ground crews. In 2008, many of the 136 standalone di... | Northrop B-2 Spirit | Wikipedia | 422 | 4396 | https://en.wikipedia.org/wiki/Northrop%20B-2%20Spirit | Technology | Specific aircraft | null |
Northrop had investigated several means of applying directional control that would infringe on the aircraft's radar profile as little as possible, eventually settling on a combination of split brake-rudders and differential thrust. Engine thrust became a key element of the B-2's aerodynamic design process early on; thr... | Northrop B-2 Spirit | Wikipedia | 496 | 4396 | https://en.wikipedia.org/wiki/Northrop%20B-2%20Spirit | Technology | Specific aircraft | null |
Radar
The B-2's clean, low-drag flying wing configuration not only provides exceptional range but is also beneficial to reducing its radar profile. Reportedly, the B-2 has a radar cross-section (RCS) of about . The bomber does not always fly stealthily; when nearing air defenses pilots "stealth up" the B-2, a maneuver ... | Northrop B-2 Spirit | Wikipedia | 451 | 4396 | https://en.wikipedia.org/wiki/Northrop%20B-2%20Spirit | Technology | Specific aircraft | null |
Burying engines deep inside the fuselage also minimizes the thermal visibility or infrared signature of the exhaust. At the engine intake, cold air from the boundary layer below the main inlet enters the fuselage (boundary layer suction, first tested on the Northrop X-21) and is mixed with hot exhaust air just before t... | Northrop B-2 Spirit | Wikipedia | 423 | 4396 | https://en.wikipedia.org/wiki/Northrop%20B-2%20Spirit | Technology | Specific aircraft | null |
Shelter system
B-2s are supported by portable, environmentally-controlled hangars called B-2 Shelter Systems (B2SS). The hangars are built by American Spaceframe Fabricators Inc. and cost approximately US$5 million apiece. The need for specialized hangars arose in 1998 when it was found that B-2s passing through Anders... | Northrop B-2 Spirit | Wikipedia | 443 | 4396 | https://en.wikipedia.org/wiki/Northrop%20B-2%20Spirit | Technology | Specific aircraft | null |
2000s
The B-2 saw service in Afghanistan, striking ground targets in support of Operation Enduring Freedom. With aerial refueling support, the B-2 flew one of its longest missions to date from Whiteman Air Force Base in Missouri to Afghanistan and back. B-2s would be stationed in the Middle East as a part of a US milit... | Northrop B-2 Spirit | Wikipedia | 453 | 4396 | https://en.wikipedia.org/wiki/Northrop%20B-2%20Spirit | Technology | Specific aircraft | null |
In August 2011, The New Yorker reported that prior to the May 2011 U.S. Special Operations raid into Abbottabad, Pakistan that resulted in the death of Osama bin Laden, U.S. officials had considered an airstrike by one or more B-2s as an alternative; the use of a bunker busting bomb was rejected due to potential damage... | Northrop B-2 Spirit | Wikipedia | 428 | 4396 | https://en.wikipedia.org/wiki/Northrop%20B-2%20Spirit | Technology | Specific aircraft | null |
United States Air Force (19 aircraft in active inventory)
Air Force Global Strike Command
509th Bomb Wing – Whiteman Air Force Base, Missouri (18 B-2s)
13th Bomb Squadron 2005–present
325th Bomb Squadron 1998–2005
393rd Bomb Squadron 1993–present
394th Combat Training Squadron 1996–2018
Air Combat Command
53rd Wing –... | Northrop B-2 Spirit | Wikipedia | 420 | 4396 | https://en.wikipedia.org/wiki/Northrop%20B-2%20Spirit | Technology | Specific aircraft | null |
In February 2010, a serious incident involving a B-2 occurred at Andersen Air Force Base in Guam. The aircraft involved was AV-11 Spirit of Washington. The aircraft was severely damaged by fire while on the ground and underwent 18 months of repairs to enable it to fly back to the mainland U.S. for more comprehensive re... | Northrop B-2 Spirit | Wikipedia | 511 | 4396 | https://en.wikipedia.org/wiki/Northrop%20B-2%20Spirit | Technology | Specific aircraft | null |
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