doc_id
int32
0
2.25M
text
stringlengths
101
8.13k
source
stringlengths
38
44
24,400
In aqueous solution at pH close to neutrality, amino acids exist as zwitterions, i.e. as dipolar ions with both and in charged states, so the overall structure is . At physiological pH the so-called "neutral forms" are not present to any measurable degree. Although the two charges in the zwitterion structure add up to ...
https://en.wikipedia.org/wiki?curid=1207
24,401
In strongly acidic conditions (pH below 3), the carboxylate group becomes protonated and the structure becomes an ammonio carboxylic acid, . This is relevant for enzymes like pepsin that are active in acidic environments such as the mammalian stomach and lysosomes, but does not significantly apply to intracellular enzy...
https://en.wikipedia.org/wiki?curid=1207
24,402
Although various definitions of acids and bases are used in chemistry, the only one that is useful for chemistry in aqueous solution is that of Brønsted: an acid is a species that can donate a proton to another species, and a base is one that can accept a proton. This criterion is used to label the groups in the above ...
https://en.wikipedia.org/wiki?curid=1207
24,403
For amino acids with uncharged side-chains the zwitterion predominates at pH values between the two p"K" values, but coexists in equilibrium with small amounts of net negative and net positive ions. At the midpoint between the two p"K" values, the trace amount of net negative and trace of net positive ions balance, so ...
https://en.wikipedia.org/wiki?curid=1207
24,404
For amino acids with charged side chains, the p"K" of the side chain is involved. Thus for aspartate or glutamate with negative side chains, the terminal amino group is essentially entirely in the charged form , but this positive charge needs to be balanced by the state with just one C-terminal carboxylate group is neg...
https://en.wikipedia.org/wiki?curid=1207
24,405
Similar considerations apply to other amino acids with ionizable side-chains, including not only glutamate (similar to aspartate), but also
https://en.wikipedia.org/wiki?curid=1207
24,406
Amino acids have zero mobility in electrophoresis at their isoelectric point, although this behaviour is more usually exploited for peptides and proteins than single amino acids. Zwitterions have minimum solubility at their isoelectric point, and some amino acids (in particular, with nonpolar side chains) can be isolat...
https://en.wikipedia.org/wiki?curid=1207
24,407
The 20 canonical amino acids can be classified according to their properties. Important factors are charge, hydrophilicity or hydrophobicity, size, and functional groups. These properties influence protein structure and protein–protein interactions. The water-soluble proteins tend to have their hydrophobic residues (Le...
https://en.wikipedia.org/wiki?curid=1207
24,408
Some amino acids have special properties. Cysteine can form covalent disulfide bonds to other cysteine residues. Proline forms a cycle to the polypeptide backbone, and glycine is more flexible than other amino acids.
https://en.wikipedia.org/wiki?curid=1207
24,409
Glycine and proline are strongly present within low complexity regions of both eukaryotic and prokaryotic proteins, whereas the opposite is the case with cysteine, phenylalanine, tryptophan, methionine, valine, leucine, isoleucine, which are highly reactive, or complex, or hydrophobic.
https://en.wikipedia.org/wiki?curid=1207
24,410
Many proteins undergo a range of posttranslational modifications, whereby additional chemical groups are attached to the amino acid residue side chains sometimes producing lipoproteins (that are hydrophobic), or glycoproteins (that are hydrophilic) allowing the protein to attach temporarily to a membrane. For example, ...
https://en.wikipedia.org/wiki?curid=1207
24,411
Although one-letter symbols are included in the table, IUPAC–IUBMB recommend that "Use of the one-letter symbols should be restricted to the comparison of long sequences".
https://en.wikipedia.org/wiki?curid=1207
24,412
Two additional amino acids are in some species coded for by codons that are usually interpreted as stop codons:
https://en.wikipedia.org/wiki?curid=1207
24,413
In addition to the specific amino acid codes, placeholders are used in cases where chemical or crystallographic analysis of a peptide or protein cannot conclusively determine the identity of a residue. They are also used to summarise conserved protein sequence motifs. The use of single letters to indicate sets of simil...
https://en.wikipedia.org/wiki?curid=1207
24,414
Ter or * (from termination) is used in notation for mutations in proteins when a stop codon occurs. It correspond to no amino acid at all.
https://en.wikipedia.org/wiki?curid=1207
24,415
In addition, many nonstandard amino acids have a specific code. For example, several peptide drugs, such as Bortezomib and MG132, are artificially synthesized and retain their protecting groups, which have specific codes. Bortezomib is Pyz–Phe–boroLeu, and MG132 is Z–Leu–Leu–Leu–al. To aid in the analysis of protein st...
https://en.wikipedia.org/wiki?curid=1207
24,416
Amino acids which have the amine group attached to the (alpha-) carbon atom next to the carboxyl group have primary importance in living organisms since they participate in protein synthesis. They are known as 2-, alpha-, or α-amino acids (generic formula in most cases, where R is an organic substituent known as a "sid...
https://en.wikipedia.org/wiki?curid=1207
24,417
Many proteinogenic and non-proteinogenic amino acids have biological functions. For example, in the human brain, glutamate (standard glutamic acid) and gamma-aminobutyric acid ("GABA", nonstandard gamma-amino acid) are, respectively, the main excitatory and inhibitory neurotransmitters. Hydroxyproline, a major componen...
https://en.wikipedia.org/wiki?curid=1207
24,418
Amino acids are the precursors to proteins. They join by condensation reactions to form short polymer chains called peptides or longer chains called either polypeptides or proteins. These chains are linear and unbranched, with each amino acid residue within the chain attached to two neighboring amino acids. In Nature, ...
https://en.wikipedia.org/wiki?curid=1207
24,419
Twenty-two amino acids are naturally incorporated into polypeptides and are called proteinogenic or natural amino acids. Of these, 20 are encoded by the universal genetic code. The remaining 2, selenocysteine and pyrrolysine, are incorporated into proteins by unique synthetic mechanisms. Selenocysteine is incorporated ...
https://en.wikipedia.org/wiki?curid=1207
24,420
Several independent evolutionary studies have suggested that Gly, Ala, Asp, Val, Ser, Pro, Glu, Leu, Thr may belong to a group of amino acids that constituted the early genetic code, whereas Cys, Met, Tyr, Trp, His, Phe may belong to a group of amino acids that constituted later additions of the genetic code.
https://en.wikipedia.org/wiki?curid=1207
24,421
The 20 amino acids that are encoded directly by the codons of the universal genetic code are called "standard" or "canonical" amino acids. A modified form of methionine ("N"-formylmethionine) is often incorporated in place of methionine as the initial amino acid of proteins in bacteria, mitochondria and chloroplasts. O...
https://en.wikipedia.org/wiki?curid=1207
24,422
The two nonstandard proteinogenic amino acids are selenocysteine (present in many non-eukaryotes as well as most eukaryotes, but not coded directly by DNA) and pyrrolysine (found only in some archaea and at least one bacterium). The incorporation of these nonstandard amino acids is rare. For example, 25 human proteins ...
https://en.wikipedia.org/wiki?curid=1207
24,423
"N"-formylmethionine (which is often the initial amino acid of proteins in bacteria, mitochondria, and chloroplasts) is generally considered as a form of methionine rather than as a separate proteinogenic amino acid. Codon–tRNA combinations not found in nature can also be used to "expand" the genetic code and form nove...
https://en.wikipedia.org/wiki?curid=1207
24,424
Aside from the 22 proteinogenic amino acids, many "non-proteinogenic" amino acids are known. Those either are not found in proteins (for example carnitine, GABA, levothyroxine) or are not produced directly and in isolation by standard cellular machinery (for example, hydroxyproline and selenomethionine).
https://en.wikipedia.org/wiki?curid=1207
24,425
Non-proteinogenic amino acids that are found in proteins are formed by post-translational modification, which is modification after translation during protein synthesis. These modifications are often essential for the function or regulation of a protein. For example, the carboxylation of glutamate allows for better bin...
https://en.wikipedia.org/wiki?curid=1207
24,426
Some non-proteinogenic amino acids are not found in proteins. Examples include 2-aminoisobutyric acid and the neurotransmitter gamma-aminobutyric acid. Non-proteinogenic amino acids often occur as intermediates in the metabolic pathways for standard amino acids – for example, ornithine and citrulline occur in the urea ...
https://en.wikipedia.org/wiki?curid=1207
24,427
When taken up into the human body from the diet, the 20 standard amino acids either are used to synthesize proteins, other biomolecules, or are oxidized to urea and carbon dioxide as a source of energy. The oxidation pathway starts with the removal of the amino group by a transaminase; the amino group is then fed into ...
https://en.wikipedia.org/wiki?curid=1207
24,428
In humans, non-protein amino acids also have important roles as metabolic intermediates, such as in the biosynthesis of the neurotransmitter gamma-aminobutyric acid (GABA). Many amino acids are used to synthesize other molecules, for example:
https://en.wikipedia.org/wiki?curid=1207
24,429
Some nonstandard amino acids are used as defenses against herbivores in plants. For example, canavanine is an analogue of arginine that is found in many legumes, and in particularly large amounts in "Canavalia gladiata" (sword bean). This amino acid protects the plants from predators such as insects and can cause illne...
https://en.wikipedia.org/wiki?curid=1207
24,430
The chelating ability of amino acids is sometimes used in fertilizers to facilitate the delivery of minerals to plants in order to correct mineral deficiencies, such as iron chlorosis. These fertilizers are also used to prevent deficiencies from occurring and to improve the overall health of the plants.
https://en.wikipedia.org/wiki?curid=1207
24,431
Amino acids are sometimes added to animal feed because some of the components of these feeds, such as soybeans, have low levels of some of the essential amino acids, especially of lysine, methionine, threonine, and tryptophan. Likewise amino acids are used to chelate metal cations in order to improve the absorption of ...
https://en.wikipedia.org/wiki?curid=1207
24,432
The food industry is a major consumer of amino acids, especially glutamic acid, which is used as a flavor enhancer, and aspartame (aspartylphenylalanine 1-methyl ester), which is used as an artificial sweetener. Amino acids are sometimes added to food by manufacturers to alleviate symptoms of mineral deficiencies, such...
https://en.wikipedia.org/wiki?curid=1207
24,433
Similarly, some amino acids derivatives are used in pharmaceutical industry. They include 5-HTP (5-hydroxytryptophan) used for experimental treatment of depression, -DOPA (-dihydroxyphenylalanine) for Parkinson's treatment, and eflornithine drug that inhibits ornithine decarboxylase and used in the treatment of sleepin...
https://en.wikipedia.org/wiki?curid=1207
24,434
Since 2001, 40 non-natural amino acids have been added into protein by creating a unique codon (recoding) and a corresponding transfer-RNA:aminoacyl – tRNA-synthetase pair to encode it with diverse physicochemical and biological properties in order to be used as a tool to exploring protein structure and function or to ...
https://en.wikipedia.org/wiki?curid=1207
24,435
Nullomers are codons that in theory code for an amino acid, however, in nature there is a selective bias against using this codon in favor of another, for example bacteria prefer to use CGA instead of AGA to code for arginine. This creates some sequences that do not appear in the genome. This characteristic can be take...
https://en.wikipedia.org/wiki?curid=1207
24,436
Amino acids are important as low-cost feedstocks. These compounds are used in chiral pool synthesis as enantiomerically pure building blocks.
https://en.wikipedia.org/wiki?curid=1207
24,437
Amino acids have been investigated as precursors chiral catalysts, such as for asymmetric hydrogenation reactions, although no commercial applications exist.
https://en.wikipedia.org/wiki?curid=1207
24,438
Amino acids have been considered as components of biodegradable polymers, which have applications as environmentally friendly packaging and in medicine in drug delivery and the construction of prosthetic implants. An interesting example of such materials is polyaspartate, a water-soluble biodegradable polymer that may ...
https://en.wikipedia.org/wiki?curid=1207
24,439
The commercial production of amino acids usually relies on mutant bacteria that overproduce individual amino acids using glucose as a carbon source. Some amino acids are produced by enzymatic conversions of synthetic intermediates. 2-Aminothiazoline-4-carboxylic acid is an intermediate in one industrial synthesis of -c...
https://en.wikipedia.org/wiki?curid=1207
24,440
In plants, nitrogen is first assimilated into organic compounds in the form of glutamate, formed from alpha-ketoglutarate and ammonia in the mitochondrion. For other amino acids, plants use transaminases to move the amino group from glutamate to another alpha-keto acid. For example, aspartate aminotransferase converts ...
https://en.wikipedia.org/wiki?curid=1207
24,441
Nonstandard amino acids are usually formed through modifications to standard amino acids. For example, homocysteine is formed through the transsulfuration pathway or by the demethylation of methionine via the intermediate metabolite "S"-adenosylmethionine, while hydroxyproline is made by a post translational modificati...
https://en.wikipedia.org/wiki?curid=1207
24,442
Microorganisms and plants synthesize many uncommon amino acids. For example, some microbes make 2-aminoisobutyric acid and lanthionine, which is a sulfide-bridged derivative of alanine. Both of these amino acids are found in peptidic lantibiotics such as alamethicin. However, in plants, 1-aminocyclopropane-1-carboxylic...
https://en.wikipedia.org/wiki?curid=1207
24,443
The formation of amino acids and peptides are assumed to precede and perhaps induce the emergence of life on earth. Amino acids can form from simple precursors under various conditions. Surface-based chemical metabolism of amino acids and very small compounds may have led to the build-up of amino acids, coenzymes and p...
https://en.wikipedia.org/wiki?curid=1207
24,444
In the famous Urey-Miller experiment, the passage of an electric arc through a mixture of methane, hydrogen, and ammonia produces a large number of amino acids. Since then, scientists have discovered a range of ways and components by which the potentially prebiotic formation and chemical evolution of peptides may have ...
https://en.wikipedia.org/wiki?curid=1207
24,445
According to a review, amino acids, and even peptides, "turn up fairly regularly in the various experimental broths that have been allowed to be cooked from simple chemicals. This is because nucleotides are far more difficult to synthesize chemically than amino acids." For a chronological order, it suggests that there ...
https://en.wikipedia.org/wiki?curid=1207
24,446
As both the amine and carboxylic acid groups of amino acids can react to form amide bonds, one amino acid molecule can react with another and become joined through an amide linkage. This polymerization of amino acids is what creates proteins. This condensation reaction yields the newly formed peptide bond and a molecul...
https://en.wikipedia.org/wiki?curid=1207
24,447
However, not all peptide bonds are formed in this way. In a few cases, peptides are synthesized by specific enzymes. For example, the tripeptide glutathione is an essential part of the defenses of cells against oxidative stress. This peptide is synthesized in two steps from free amino acids. In the first step, gamma-gl...
https://en.wikipedia.org/wiki?curid=1207
24,448
In chemistry, peptides are synthesized by a variety of reactions. One of the most-used in solid-phase peptide synthesis uses the aromatic oxime derivatives of amino acids as activated units. These are added in sequence onto the growing peptide chain, which is attached to a solid resin support. Libraries of peptides are...
https://en.wikipedia.org/wiki?curid=1207
24,449
The combination of functional groups allow amino acids to be effective polydentate ligands for metal–amino acid chelates.
https://en.wikipedia.org/wiki?curid=1207
24,450
Degradation of an amino acid often involves deamination by moving its amino group to alpha-ketoglutarate, forming glutamate. This process involves transaminases, often the same as those used in amination during synthesis. In many vertebrates, the amino group is then removed through the urea cycle and is excreted in the...
https://en.wikipedia.org/wiki?curid=1207
24,451
The total nitrogen content of organic matter is mainly formed by the amino groups in proteins. The Total Kjeldahl Nitrogen (TKN) is a measure of nitrogen widely used in the analysis of (waste) water, soil, food, feed and organic matter in general. As the name suggests, the Kjeldahl method is applied. More sensitive met...
https://en.wikipedia.org/wiki?curid=1207
24,452
In software development, agile (sometimes written Agile) practices include requirements discovery and solutions improvement through the collaborative effort of self-organizing and cross-functional teams with their customer(s)/end user(s), adaptive planning, evolutionary development, early delivery, continual improvemen...
https://en.wikipedia.org/wiki?curid=639009
24,453
Popularized in the 2001 "Manifesto for Agile Software Development", these values and principles were derived from and underpin a broad range of software development frameworks, including Scrum and Kanban.
https://en.wikipedia.org/wiki?curid=639009
24,454
While there is much anecdotal evidence that adopting agile practices and values improves the effectiveness of software professionals, teams and organizations, the empirical evidence is mixed and hard to find.
https://en.wikipedia.org/wiki?curid=639009
24,455
Iterative and incremental software development methods can be traced back as early as 1957, with evolutionary project management and adaptive software development emerging in the early 1970s.
https://en.wikipedia.org/wiki?curid=639009
24,456
During the 1990s, a number of "lightweight" software development methods evolved in reaction to the prevailing "heavyweight" methods (often referred to collectively as "waterfall") that critics described as overly regulated, planned, and micromanaged. These lightweight methods included: rapid application development (R...
https://en.wikipedia.org/wiki?curid=639009
24,457
Already since 1991 similar changes had been underway in manufacturing and management thinking derived from Lean management.
https://en.wikipedia.org/wiki?curid=639009
24,458
In 2001, seventeen software developers met at a resort in Snowbird, Utah to discuss lightweight development methods. They were: Kent Beck (Extreme Programming), Ward Cunningham (Extreme Programming), Dave Thomas (PragProg, Ruby), Jeff Sutherland (Scrum), Ken Schwaber (Scrum), Jim Highsmith (Adaptive Software Developmen...
https://en.wikipedia.org/wiki?curid=639009
24,459
In 2005, a group headed by Cockburn and Highsmith wrote an addendum of project management principles, the PM Declaration of Interdependence, to guide software project management according to agile software development methods.
https://en.wikipedia.org/wiki?curid=639009
24,460
In 2009, a group working with Martin wrote an extension of software development principles, the Software Craftsmanship Manifesto, to guide agile software development according to professional conduct and mastery.
https://en.wikipedia.org/wiki?curid=639009
24,461
In 2011, the Agile Alliance created the "Guide to Agile Practices" (renamed the "Agile Glossary" in 2016), an evolving open-source compendium of the working definitions of agile practices, terms, and elements, along with interpretations and experience guidelines from the worldwide community of agile practitioners.
https://en.wikipedia.org/wiki?curid=639009
24,462
Based on their combined experience of developing software and helping others do that, the authors of the manifesto declared that they valued:
https://en.wikipedia.org/wiki?curid=639009
24,463
That is to say, while both sides have value and the items on the right should be considered, the authors felt that the items on the left should have more influence on how people approach their work.
https://en.wikipedia.org/wiki?curid=639009
24,464
Some of the authors formed the Agile Alliance, a non-profit organization that promotes software development according to the manifesto's values and principles. Introducing the manifesto on behalf of the Agile Alliance, Jim Highsmith said,
https://en.wikipedia.org/wiki?curid=639009
24,465
Most agile development methods break product development work into small increments that minimize the amount of up-front planning and design. Iterations, or sprints, are short time frames (timeboxes) that typically last from one to four weeks. Each iteration involves a cross-functional team working in all functions: pl...
https://en.wikipedia.org/wiki?curid=639009
24,466
A key advantage of agile approaches is speed to market and risk mitigation. Smaller increments are typically released to market, reducing the time and cost risks of engineering a product that doesn't meet user requirements.
https://en.wikipedia.org/wiki?curid=639009
24,467
The 6th principle of the agile manifesto for software development states "The most efficient and effective method of conveying information to and within a development team is face-to-face conversation". The manifesto, written in 2001 when video conferencing was not widely used, states this in relation to the communicat...
https://en.wikipedia.org/wiki?curid=639009
24,468
The principle of co-location is that co-workers on the same team should be situated together to better establish the identity as a team and to improve communication. This enables face-to-face interaction, ideally in front of a whiteboard, that reduces the cycle time typically taken when questions and answers are mediat...
https://en.wikipedia.org/wiki?curid=639009
24,469
No matter which development method is followed, every team should include a customer representative (known as "product owner" in Scrum). This representative is agreed by stakeholders to act on their behalf and makes a personal commitment to being available for developers to answer questions throughout the iteration. At...
https://en.wikipedia.org/wiki?curid=639009
24,470
In agile software development, an information radiator is a (normally large) physical display, board with sticky notes or similar, located prominently near the development team, where passers-by can see it. It presents an up-to-date summary of the product development status. A build light indicator may also be used to ...
https://en.wikipedia.org/wiki?curid=639009
24,471
A common characteristic in agile software development is the daily stand-up (known as "daily scrum" in the Scrum framework). In a brief session (e.g., 15 minutes), team members review collectively how they are progressing toward their goal and agree whether they need to adapt their approach. To keep to the agreed time ...
https://en.wikipedia.org/wiki?curid=639009
24,472
Specific tools and techniques, such as continuous integration, automated unit testing, pair programming, test-driven development, design patterns, behavior-driven development, domain-driven design, code refactoring and other techniques are often used to improve quality and enhance product development agility. This is p...
https://en.wikipedia.org/wiki?curid=639009
24,473
Compared to traditional software engineering, agile software development mainly targets complex systems and product development with dynamic, non-deterministic and non-linear characteristics. Accurate estimates, stable plans, and predictions are often hard to get in early stages, and confidence in them is likely to be ...
https://en.wikipedia.org/wiki?curid=639009
24,474
Development methods exist on a continuum from "adaptive" to "predictive". Agile software development methods lie on the "adaptive" side of this continuum. One key of adaptive development methods is a "rolling wave" approach to schedule planning, which identifies milestones but leaves flexibility in the path to reach th...
https://en.wikipedia.org/wiki?curid=639009
24,475
"Adaptive" methods focus on adapting quickly to changing realities. When the needs of a project change, an adaptive team changes as well. An adaptive team has difficulty describing exactly what will happen in the future. The further away a date is, the more vague an adaptive method is about what will happen on that dat...
https://en.wikipedia.org/wiki?curid=639009
24,476
"Predictive" methods, in contrast, focus on analysing and planning the future in detail and cater for known risks. In the extremes, a predictive team can report exactly what features and tasks are planned for the entire length of the development process. Predictive methods rely on effective early phase analysis and if ...
https://en.wikipedia.org/wiki?curid=639009
24,477
Risk analysis can be used to choose between adaptive ("agile" or "value-driven") and predictive ("plan-driven") methods. Barry Boehm and Richard Turner suggest that each side of the continuum has its own "home ground", as follows:
https://en.wikipedia.org/wiki?curid=639009
24,478
One of the differences between agile software development methods and waterfall is the approach to quality and testing. In the waterfall model, work moves through software development lifecycle (SDLC) phases—with one phase being completed before another can start—hence the testing phase is separate and follows a build ...
https://en.wikipedia.org/wiki?curid=639009
24,479
Because testing is done in every iteration—which develops a small piece of the software—users can frequently use those new pieces of software and validate the value. After the users know the real value of the updated piece of software, they can make better decisions about the software's future. Having a value retrospec...
https://en.wikipedia.org/wiki?curid=639009
24,480
This iterative approach supports a "product" rather than a "project" mindset. This provides greater flexibility throughout the development process; whereas on projects the requirements are defined and locked down from the very beginning, making it difficult to change them later. Iterative product development allows the...
https://en.wikipedia.org/wiki?curid=639009
24,481
In a letter to "IEEE Computer", Steven Rakitin expressed cynicism about agile software development, calling it ""yet another attempt to undermine the discipline of software engineering"" and translating ""working software over comprehensive documentation"" as ""we want to spend all our time coding. Remember, real progr...
https://en.wikipedia.org/wiki?curid=639009
24,482
This is disputed by proponents of agile software development, who state that developers should write documentation if that is the best way to achieve the relevant goals, but that there are often better ways to achieve those goals than writing static documentation.
https://en.wikipedia.org/wiki?curid=639009
24,483
Scott Ambler states that documentation should be "just barely good enough" (JBGE), that too much or comprehensive documentation would usually cause waste, and developers rarely trust detailed documentation because it's usually out of sync with code, while too little documentation may also cause problems for maintenance...
https://en.wikipedia.org/wiki?curid=639009
24,484
Agile software development methods support a broad range of the software development life cycle. Some methods focus on the practices (e.g., XP, pragmatic programming, agile modeling), while some focus on managing the flow of work (e.g., Scrum, Kanban). Some support activities for requirements specification and developm...
https://en.wikipedia.org/wiki?curid=639009
24,485
Agile software development is supported by a number of concrete practices, covering areas like requirements, design, modeling, coding, testing, planning, risk management, process, quality, etc. Some notable agile software development practices include:
https://en.wikipedia.org/wiki?curid=639009
24,486
In the literature, different terms refer to the notion of method adaptation, including 'method tailoring', 'method fragment adaptation' and 'situational method engineering'. Method tailoring is defined as:
https://en.wikipedia.org/wiki?curid=639009
24,487
Situation-appropriateness should be considered as a distinguishing characteristic between agile methods and more plan-driven software development methods, with agile methods allowing product development teams to adapt working practices according to the needs of individual products. Potentially, most agile methods could...
https://en.wikipedia.org/wiki?curid=639009
24,488
In practice, methods can be tailored using various tools. Generic process modeling languages such as Unified Modeling Language can be used to tailor software development methods. However, dedicated tools for method engineering such as the Essence Theory of Software Engineering of SEMAT also exist.
https://en.wikipedia.org/wiki?curid=639009
24,489
Agile software development has been widely seen as highly suited to certain types of environments, including small teams of experts working on greenfield projects, and the challenges and limitations encountered in the adoption of agile software development methods in a large organization with legacy infrastructure are ...
https://en.wikipedia.org/wiki?curid=639009
24,490
In response, a range of strategies and patterns has evolved for overcoming challenges with large-scale development efforts (>20 developers) or distributed (non-colocated) development teams, amongst other challenges; and there are now several recognized frameworks that seek to mitigate or avoid these challenges.
https://en.wikipedia.org/wiki?curid=639009
24,491
There are many conflicting viewpoints on whether all of these are effective or indeed fit the definition of agile development, and this remains an active and ongoing area of research.
https://en.wikipedia.org/wiki?curid=639009
24,492
When agile software development is applied in a distributed setting (with teams dispersed across multiple business locations), it is commonly referred to as distributed agile software development. The goal is to leverage the unique benefits offered by each approach. Distributed development allows organizations to build...
https://en.wikipedia.org/wiki?curid=639009
24,493
Agile software development methods were initially seen as best suitable for non-critical product developments, thereby excluded from use in regulated domains such as medical devices, pharmaceutical, financial, nuclear systems, automotive, and avionics sectors, etc. However, in the last several years, there have been se...
https://en.wikipedia.org/wiki?curid=639009
24,494
There are numerous standards that may apply in regulated domains, including ISO 26262, ISO 9000, ISO 9001, and ISO/IEC 15504.
https://en.wikipedia.org/wiki?curid=639009
24,495
Although agile software development methods can be used with any programming paradigm or language in practice, they were originally closely associated with object-oriented environments such as Smalltalk, Lisp and later Java, C#. The initial adopters of agile methods were usually small to medium-sized teams working on u...
https://en.wikipedia.org/wiki?curid=639009
24,496
The "Agility measurement index", amongst others, rates developments against five dimensions of product development (duration, risk, novelty, effort, and interaction). Other techniques are based on measurable goals and one study suggests that velocity can be used as a metric of agility. There are also agile self-assessm...
https://en.wikipedia.org/wiki?curid=639009
24,497
One of the early studies reporting gains in quality, productivity, and business satisfaction by using agile software developments methods was a survey conducted by Shine Technologies from November 2002 to January 2003.
https://en.wikipedia.org/wiki?curid=639009
24,498
A similar survey, the "State of Agile", is conducted every year starting in 2006 with thousands of participants from around the software development community. This tracks trends on the perceived benefits of agility, lessons learned, and good practices. Each survey has reported increasing numbers saying that agile soft...
https://en.wikipedia.org/wiki?curid=639009
24,499
Organizations and teams implementing agile software development often face difficulties transitioning from more traditional methods such as waterfall development, such as teams having an agile process forced on them. These are often termed "agile anti-patterns" or more commonly "agile smells". Below are some common exa...
https://en.wikipedia.org/wiki?curid=639009