text
stringlengths 31
999
| source
stringclasses 5
values |
|---|---|
The UNIVAC LARC, short for the Livermore Advanced Research Computer, is a mainframe computer designed to a requirement published by Edward Teller in order to run hydrodynamic simulations for nuclear weapon design. It was one of the earliest supercomputers. LARC supported multiprocessing with two CPUs (called Computers) and an input/output (I/O) Processor (called the Processor)
|
https://huggingface.co/datasets/fmars/wiki_stem
|
The history of computing hardware covers the developments from early simple devices to aid calculation to modern day computers.
The first aids to computation were purely mechanical devices which required the operator to set up the initial values of an elementary arithmetic operation, then manipulate the device to obtain the result. Later, computers represented numbers in a continuous form (e
|
https://huggingface.co/datasets/fmars/wiki_stem
|
A digital differential analyzer (DDA), also sometimes called a digital integrating computer, is a digital implementation of a differential analyzer. The integrators in a DDA are implemented as accumulators, with the numeric result converted back to a pulse rate by the overflow of the accumulator.
The primary advantages of a DDA over the conventional analog differential analyzer are greater precision of the results and the lack of drift/noise/slip/lash in the calculations
|
https://huggingface.co/datasets/fmars/wiki_stem
|
A sense switch, or program switch, is a switch on the front panel of a computer whose state can be tested by conditional branch instructions in software. Most early computers had several sense switches. They were typically used by the operator to set program options
|
https://huggingface.co/datasets/fmars/wiki_stem
|
A serial computer is a computer typified by bit-serial architecture – i. e. , internally operating on one bit or digit for each clock cycle
|
https://huggingface.co/datasets/fmars/wiki_stem
|
One meaning of system console, computer console, root console, operator's console, or simply console is the text entry and display device for system administration messages, particularly those from the BIOS or boot loader, the kernel, from the init system and from the system logger. It is a physical device consisting of a keyboard and a screen, and traditionally is a text terminal, but may also be a graphical terminal. System consoles are generalized to computer terminals, which are abstracted respectively by virtual consoles and terminal emulators
|
https://huggingface.co/datasets/fmars/wiki_stem
|
The tyranny of numbers was a problem faced in the 1960s by computer engineers. Engineers were unable to increase the performance of their designs due to the huge number of components involved. In theory, every component needed to be wired to every other component (or at least many other components) and were typically strung and soldered by hand
|
https://huggingface.co/datasets/fmars/wiki_stem
|
The Atanasoff–Berry computer (ABC) was the first automatic electronic digital computer. Limited by the technology of the day, and execution, the device has remained somewhat obscure. The ABC's priority is debated among historians of computer technology, because it was neither programmable, nor Turing-complete
|
https://huggingface.co/datasets/fmars/wiki_stem
|
The RCA BIZMAC was a vacuum tube computer manufactured by RCA from 1956 to 1962. Although RCA was noted for their pioneering work in transistors, RCA decided to build a vacuum tube computer instead of a transistorized computer. It was the largest vacuum tube computer of its time in 1956, occupying 20,000 sq ft (1,900 m2) of floor space with up to 30,000 tubes, 70,000 diodes, and 35,000 magnetic cores
|
https://huggingface.co/datasets/fmars/wiki_stem
|
== Imperial College Computing Engines ==
ICCE I and ICCE II were digital computers built at the Imperial College Department of Mathematics in the post-war period.
ICCE I
The first Imperial College Computing Engine, ICCE I, was constructed by Sidney Michaelson, Tony Brooker and Keith Tocher in the Department of Mathematics at Imperial College London in the late 1940s and early 1950s. It was a relay based machine which gave relatively slow but highly reliable service
|
https://huggingface.co/datasets/fmars/wiki_stem
|
The Computron was an electron tube designed to perform the parallel addition and multiplication of digital numbers. It was conceived by Richard L. Snyder, Jr
|
https://huggingface.co/datasets/fmars/wiki_stem
|
DATAR, short for Digital Automated Tracking and Resolving, was a pioneering computerized battlefield information system. DATAR combined the data from all of the sensors in a naval task force into a single "overall view" that was then transmitted back to all of the ships and displayed on plan-position indicators similar to radar displays. Commanders could then see information from everywhere, not just their own ship's sensors
|
https://huggingface.co/datasets/fmars/wiki_stem
|
The differential analyser is a mechanical analogue computer designed to solve differential equations by integration, using wheel-and-disc mechanisms to perform the integration. It was one of the first advanced computing devices to be used operationally.
The original machines could not add, but then it was noticed that if the two wheels of a rear differential are turned, the drive shaft will compute the average of the left and right wheels
|
https://huggingface.co/datasets/fmars/wiki_stem
|
Eucrates was a hybrid teaching and learning analog computer created by Gordon Pask in 1956, in response to a request by the Solartron Electronic Group for a machine to exhibit at the Physical Society Exhibition in London.
Its operation was based on simulating the functioning of neurons.
The Solartron EUCRATES II was created by C
|
https://huggingface.co/datasets/fmars/wiki_stem
|
The Monte Carlo trolley, or FERMIAC, was an analog computer invented by physicist Enrico Fermi to aid in his studies of neutron transport.
Operation
The FERMIAC employed the Monte Carlo method to model neutron transport in various types of nuclear systems. Given an initial distribution of neutrons, the goal of the process is to develop numerous "neutron genealogies", or models of the behavior of individual neutrons, including each collision, scattering, and fission
|
https://huggingface.co/datasets/fmars/wiki_stem
|
ILLIAC (Illinois Automatic Computer) was a series of supercomputers built at a variety of locations, some at the University of Illinois at Urbana–Champaign. In all, five computers were built in this series between 1951 and 1974. Some more modern projects also use the name
|
https://huggingface.co/datasets/fmars/wiki_stem
|
The MADDIDA (Magnetic Drum Digital Differential Analyzer) was a special-purpose digital computer used for solving systems of ordinary differential equations. It was the first computer to represent bits using voltage levels and whose entire logic was specified in Boolean algebra.
Invented by Floyd Steele, MADDIDA was developed at Northrop Aircraft Corporation between 1946 and 1949 to be used as a guidance system for the Snark missile
|
https://huggingface.co/datasets/fmars/wiki_stem
|
The Parametron Computer 1 (PC-1) was a binary, single-address computer developed at Professor Hidetosi Takahasi's Laboratory at the Department of Physics, University of Tokyo, and was one of the first general purpose computers that used parametron components and dual frequency magnetic-core memory. Construction started in September 1957 and was completed on March 26, 1958. The PC-1 was used at Takahasi's Laboratory for research related both to hardware and software and the researchers in the Faculty of Science also used it for scientific computing
|
https://huggingface.co/datasets/fmars/wiki_stem
|
A vacuum-tube computer, now termed a first-generation computer, is a computer that uses vacuum tubes for logic circuitry. Although superseded by second-generation transistorized computers, vacuum-tube computers continued to be built into the 1960s. These computers were mostly one-of-a-kind designs
|
https://huggingface.co/datasets/fmars/wiki_stem
|
The Wisconsin Integrally Synchronized Computer (WISC) was an early digital computer designed and built at the University of Wisconsin–Madison. Operational in 1954, it was the first digital computer in the state.
Pioneering computer designer Gene Amdahl drafted the WISC's design as his PhD thesis
|
https://huggingface.co/datasets/fmars/wiki_stem
|
In computer science, transaction processing is information processing that is divided into individual, indivisible operations called transactions. Each transaction must succeed or fail as a complete unit; it can never be only partially complete.
For example, when you purchase a book from an online bookstore, you exchange money (in the form of credit) for a book
|
https://huggingface.co/datasets/fmars/wiki_stem
|
Active redundancy is a design concept that increases operational availability and that reduces operating cost by automating most critical maintenance actions.
This concept is related to condition-based maintenance and fault reporting.
History
The initial requirement began with military combat systems during World War I
|
https://huggingface.co/datasets/fmars/wiki_stem
|
Checkpointing is a technique that provides fault tolerance for computing systems. It basically consists of saving a snapshot of the application's state, so that applications can restart from that point in case of failure. This is particularly important for long running applications that are executed in failure-prone computing systems
|
https://huggingface.co/datasets/fmars/wiki_stem
|
A Byzantine fault (also Byzantine generals problem, interactive consistency, source congruency, error avalanche, Byzantine agreement problem, and Byzantine failure) is a condition of a computer system, particularly distributed computing systems, where components may fail and there is imperfect information on whether a component has failed. The term takes its name from an allegory, the "Byzantine generals problem", developed to describe a situation in which, to avoid catastrophic failure of the system, the system's actors must agree on a concerted strategy, but some of these actors are unreliable.
In a Byzantine fault, a component such as a server can inconsistently appear both failed and functioning to failure-detection systems, presenting different symptoms to different observers
|
https://huggingface.co/datasets/fmars/wiki_stem
|
A computer cluster is a set of computers that work together so that they can be viewed as a single system. Unlike grid computers, computer clusters have each node set to perform the same task, controlled and scheduled by software.
The components of a cluster are usually connected to each other through fast local area networks, with each node (computer used as a server) running its own instance of an operating system
|
https://huggingface.co/datasets/fmars/wiki_stem
|
In distributed computing, a conflict-free replicated data type (CRDT) is a data structure that is replicated across multiple computers in a network, with the following features:
The application can update any replica independently, concurrently and without coordinating with other replicas.
An algorithm (itself part of the data type) automatically resolves any inconsistencies that might occur.
Although replicas may have different state at any particular point in time, they are guaranteed to eventually converge
|
https://huggingface.co/datasets/fmars/wiki_stem
|
A fundamental problem in distributed computing and multi-agent systems is to achieve overall system reliability in the presence of a number of faulty processes. This often requires coordinating processes to reach consensus, or agree on some data value that is needed during computation. Example applications of consensus include agreeing on what transactions to commit to a database in which order, state machine replication, and atomic broadcasts
|
https://huggingface.co/datasets/fmars/wiki_stem
|
In computer main memory, auxiliary storage and computer buses, data redundancy is the existence of data that is additional to the actual data and permits correction of errors in stored or transmitted data. The additional data can simply be a complete copy of the actual data (a type of repetition code), or only select pieces of data that allow detection of errors and reconstruction of lost or damaged data up to a certain level.
For example, by including computed check bits, ECC memory is capable of detecting and correcting single-bit errors within each memory word, while RAID 1 combines two hard disk drives (HDDs) into a logical storage unit that allows stored data to survive a complete failure of one drive
|
https://huggingface.co/datasets/fmars/wiki_stem
|
A disk array is a disk storage system which contains multiple disk drives. It is differentiated from a disk enclosure, in that an array has cache memory and advanced functionality, like RAID, deduplication, encryption and virtualization.
Components of a disk array include:
Disk array controllers
Cache in form of both volatile random-access memory and non-volatile flash memory
|
https://huggingface.co/datasets/fmars/wiki_stem
|
A disk array controller is a device that manages the physical disk drives and presents them to the computer as logical units. It almost always implements hardware RAID, thus it is sometimes referred to as RAID controller. It also often provides additional disk cache
|
https://huggingface.co/datasets/fmars/wiki_stem
|
In data storage, disk mirroring is the replication of logical disk volumes onto separate physical hard disks in real time to ensure continuous availability. It is most commonly used in RAID 1. A mirrored volume is a complete logical representation of separate volume copies
|
https://huggingface.co/datasets/fmars/wiki_stem
|
In reliability engineering, dual modular redundancy (DMR) is when components of a system are duplicated, providing redundancy in case one should fail. It is particularly applied to systems where the duplicated components work in parallel, particularly in fault-tolerant computer systems. A typical example is a complex computer system which has duplicated nodes, so that should one node fail, another is ready to carry on its work
|
https://huggingface.co/datasets/fmars/wiki_stem
|
Error correction code memory (ECC memory) is a type of computer data storage that uses an error correction code (ECC) to detect and correct n-bit data corruption which occurs in memory. ECC memory is used in most computers where data corruption cannot be tolerated, like industrial control applications, critical databases, and infrastructural memory caches.
Typically, ECC memory maintains a memory system immune to single-bit errors: the data that is read from each word is always the same as the data that had been written to it, even if one of the bits actually stored has been flipped to the wrong state
|
https://huggingface.co/datasets/fmars/wiki_stem
|
An error-tolerant design (or human-error-tolerant design) is one that does not unduly penalize user or human errors. It is the human equivalent of fault tolerant design that allows equipment to continue functioning in the presence of hardware faults, such as a "limp-in" mode for an automobile electronics unit that would be employed if something like the oxygen sensor failed.
Use of behavior shaping constraints to prevent errors
Use of forcing functions or behavior-shaping constraints is one technique in error-tolerant design
|
https://huggingface.co/datasets/fmars/wiki_stem
|
In engineering, a fail-safe is a design feature or practice that, in the event of a specific type of failure, inherently responds in a way that will cause minimal or no harm to other equipment, to the environment or to people. Unlike inherent safety to a particular hazard, a system being "fail-safe" does not mean that failure is impossible or improbable, but rather that the system's design prevents or mitigates unsafe consequences of the system's failure. That is, if and when a "fail-safe" system fails, it remains at least as safe as it was before the failure
|
https://huggingface.co/datasets/fmars/wiki_stem
|
Failover is switching to a redundant or standby computer server, system, hardware component or network upon the failure or abnormal termination of the previously active application, server, system, hardware component, or network in a computer network. Failover and switchover are essentially the same operation, except that failover is automatic and usually operates without warning, while switchover requires human intervention.
Systems designers usually provide failover capability in servers, systems or networks requiring near-continuous availability and a high degree of reliability
|
https://huggingface.co/datasets/fmars/wiki_stem
|
In a distributed computing system, a failure detector is a computer application or a subsystem that is responsible for the detection of node failures or crashes. Failure detectors were first introduced in 1996 by Chandra and Toueg in their book Unreliable Failure Detectors for Reliable Distributed Systems. The book depicts the failure detector as a tool to improve consensus (the achievement of reliability) and atomic broadcast (the same sequence of messages) in the distributed system
|
https://huggingface.co/datasets/fmars/wiki_stem
|
Fencing is the process of isolating a node of a computer cluster or protecting shared resources when a node appears to be malfunctioning. As the number of nodes in a cluster increases, so does the likelihood that one of them may fail at some point. The failed node may have control over shared resources that need to be reclaimed and if the node is acting erratically, the rest of the system needs to be protected
|
https://huggingface.co/datasets/fmars/wiki_stem
|
FlockDB was an open-source distributed, fault-tolerant graph database for managing wide but shallow network graphs. It was initially used by Twitter to store relationships between users, e. g
|
https://huggingface.co/datasets/fmars/wiki_stem
|
Gbcast (also known as group broadcast) is a reliable multicast protocol that provides ordered, fault-tolerant (all-or-none) message delivery in a group of receivers within a network of machines that experience crash failure. The protocol is capable of solving Consensus in a network of unreliable processors, and can be used to implement state machine replication. Gbcast can be used in a standalone manner, or can support the virtual synchrony execution model, in which case Gbcast is normally used for group membership management while other, faster, protocols are often favored for routine communication tasks
|
https://huggingface.co/datasets/fmars/wiki_stem
|
Geoplexing is a computer science term relating to the duplication of computer storage and applications within a server farm over geographically diverse locations for the purpose of fault tolerance. The name comes from a contraction of geographical multiplex.
Description
In a geoplex, server clusters are duplicated over one or more geographically separate sites
|
https://huggingface.co/datasets/fmars/wiki_stem
|
High-availability clusters (also known as HA clusters, fail-over clusters) are groups of computers that support server applications that can be reliably utilized with a minimum amount of down-time. They operate by using high availability software to harness redundant computers in groups or clusters that provide continued service when system components fail. Without clustering, if a server running a particular application crashes, the application will be unavailable until the crashed server is fixed
|
https://huggingface.co/datasets/fmars/wiki_stem
|
A hot spare or warm spare or hot standby is used as a failover mechanism to provide reliability in system configurations. The hot spare is active and connected as part of a working system. When a key component fails, the hot spare is switched into operation
|
https://huggingface.co/datasets/fmars/wiki_stem
|
Hot swapping is the replacement or addition of components to a computer system without stopping, shutting down, or rebooting the system; hot plugging describes the addition of components only. Components which have such functionality are said to be hot-swappable or hot-pluggable; likewise, components which do not are cold-swappable or cold-pluggable.
Most desktop computer hardware, such as CPUs and memory, are only cold-pluggable
|
https://huggingface.co/datasets/fmars/wiki_stem
|
Lockstep systems are fault-tolerant computer systems that run the same set of operations at the same time in parallel. The redundancy (duplication) allows error detection and error correction: the output from lockstep operations can be compared to determine if there has been a fault if there are at least two systems (dual modular redundancy), and the error can be automatically corrected if there are at least three systems (triple modular redundancy), via majority vote. The term "lockstep" originates from army usage, where it refers to synchronized walking, in which marchers walk as closely together as physically practical
|
https://huggingface.co/datasets/fmars/wiki_stem
|
A log-structured filesystem is a file system in which data and metadata are written sequentially to a circular buffer, called a log. The design was first proposed in 1988 by John K. Ousterhout and Fred Douglis and first implemented in 1992 by Ousterhout and Mendel Rosenblum for the Unix-like Sprite distributed operating system
|
https://huggingface.co/datasets/fmars/wiki_stem
|
In the context of virtualization, where a guest simulation of an entire computer is actually merely a software virtual machine (VM) running on a host computer under a hypervisor, migration (also known as teleportation) is the process by which a running virtual machine is moved from one physical host to another, with little or no disruption in service.
Subjective effects
Ideally, the process is completely transparent, resulting in no disruption of service (or downtime). In practice, there is always some minor pause in availability, though it may be low enough that only hard real-time systems are affected
|
https://huggingface.co/datasets/fmars/wiki_stem
|
In computer storage, multipath I/O is a fault-tolerance and performance-enhancement technique that defines more than one physical path between the CPU in a computer system and its mass-storage devices through the buses, controllers, switches, and bridge devices connecting them.
As an example, a SCSI hard disk drive may connect to two SCSI controllers on the same computer, or a disk may connect to two Fibre Channel ports. Should one controller, port or switch fail, the operating system can route the I/O through the remaining controller, port or switch transparently and with no changes visible to the applications, other than perhaps resulting in increased latency
|
https://huggingface.co/datasets/fmars/wiki_stem
|
N-version programming (NVP), also known as multiversion programming or multiple-version dissimilar software, is a method or process in software engineering where multiple functionally equivalent programs are independently generated from the same initial specifications. The concept of N-version programming was introduced in 1977 by Liming Chen and Algirdas Avizienis with the central conjecture that the "independence of programming efforts will greatly reduce the probability of identical software faults occurring in two or more versions of the program". The aim of NVP is to improve the reliability of software operation by building in fault tolerance or redundancy
|
https://huggingface.co/datasets/fmars/wiki_stem
|
NonStop is a series of server computers introduced to market in 1976 by Tandem Computers Inc. , beginning with the NonStop product line. It was followed by the Tandem Integrity NonStop line of lock-step fault tolerant computers, now defunct (not to be confused with the later and much different Hewlett-Packard Integrity product line extension)
|
https://huggingface.co/datasets/fmars/wiki_stem
|
NonStop SQL is a commercial relational database management system that is designed for fault tolerance and scalability, currently offered by Hewlett Packard Enterprise. The latest version is SQL/MX 3. 4
|
https://huggingface.co/datasets/fmars/wiki_stem
|
OpenVMS, often referred to as just VMS, is a multi-user, multiprocessing and virtual memory-based operating system. It is designed to support time-sharing, batch processing, transaction processing and workstation applications. Customers using OpenVMS include banks and financial services, hospitals and healthcare, telecommunications operators, network information services, and industrial manufacturers
|
https://huggingface.co/datasets/fmars/wiki_stem
|
Operational availability in systems engineering is a measurement of how long a system has been available to use when compared with how long it should have been available to be used.
Definition
Operational availability is a management concept that evaluates the following.
Diagnostic down time
Criticality
Fault isolation down time
Logistics delay down time
Corrective maintenance down timeAny failed item that is not corrected will induce operational failure
|
https://huggingface.co/datasets/fmars/wiki_stem
|
Paxos is a family of protocols for solving consensus in a network of unreliable or fallible processors.
Consensus is the process of agreeing on one result among a group of participants. This problem becomes difficult when the participants or their communications may experience failures
|
https://huggingface.co/datasets/fmars/wiki_stem
|
Quantum error correction (QEC) is used in quantum computing to protect quantum information from errors due to decoherence and other quantum noise. Quantum error correction is theorised as essential to achieve fault tolerant quantum computing that can reduce the effects of noise on stored quantum information, faulty quantum gates, faulty quantum preparation, and faulty measurements. This would allow algorithms of greater circuit depth
|
https://huggingface.co/datasets/fmars/wiki_stem
|
Raft is a consensus algorithm designed as an alternative to the Paxos family of algorithms. It was meant to be more understandable than Paxos by means of separation of logic, but it is also formally proven safe and offers some additional features. Raft offers a generic way to distribute a state machine across a cluster of computing systems, ensuring that each node in the cluster agrees upon the same series of state transitions
|
https://huggingface.co/datasets/fmars/wiki_stem
|
H2BK5ac is an epigenetic modification to the DNA packaging protein Histone H2B. It is a mark that indicates the acetylation at the 5th lysine residue of the histone H2B protein. H2BK5ac is involved in maintaining stem cells and colon cancer
|
https://huggingface.co/datasets/fmars/wiki_stem
|
H3K4me1 is an epigenetic modification to the DNA packaging protein Histone H3. It is a mark that indicates the mono-methylation at the 4th lysine residue of the histone H3 protein and often associated with gene enhancers.
Nomenclature
H3K4me1 indicates monomethylation of lysine 4 on histone H3 protein subunit:
Lysine methylation
This diagram shows the progressive methylation of a lysine residue
|
https://huggingface.co/datasets/fmars/wiki_stem
|
H3K4me3 is an epigenetic modification to the DNA packaging protein Histone H3 that indicates tri-methylation at the 4th lysine residue of the histone H3 protein and is often involved in the regulation of gene expression. The name denotes the addition of three methyl groups (trimethylation) to the lysine 4 on the histone H3 protein.
H3 is used to package DNA in eukaryotic cells (including human cells), and modifications to the histone alter the accessibility of genes for transcription
|
https://huggingface.co/datasets/fmars/wiki_stem
|
H3K9ac is an epigenetic modification to the DNA packaging protein Histone H3. It is a mark that indicates the acetylation at the 9th lysine residue of the histone H3 protein.
The H3K9 histone has two jobs
|
https://huggingface.co/datasets/fmars/wiki_stem
|
H3K9me2 is an epigenetic modification to the DNA packaging protein Histone H3. It is a mark that indicates the di-methylation at the 9th lysine residue of the histone H3 protein. H3K9me2 is strongly associated with transcriptional repression
|
https://huggingface.co/datasets/fmars/wiki_stem
|
H3K9me3 is an epigenetic modification to the DNA packaging protein Histone H3. It is a mark that indicates the tri-methylation at the 9th lysine residue of the histone H3 protein and is often associated with heterochromatin.
Nomenclature
H3K9me3 indicates trimethylation of lysine 9 on histone H3 protein subunit:
Lysine Methylation
This diagram shows the progressive methylation of a lysine residue
|
https://huggingface.co/datasets/fmars/wiki_stem
|
H3K14ac is an epigenetic modification to the DNA packaging protein Histone H3. It is a mark that indicates the acetylation at the 14th lysine residue of the histone H3 protein.
H3K14ac has not been widely studied partly due to previous lack of commercially available antibody
|
https://huggingface.co/datasets/fmars/wiki_stem
|
H3K23ac is an epigenetic modification to the DNA packaging protein Histone H3. It is a mark that indicates the acetylation at the 23rd lysine residue of the histone H3 protein.
H3K23ac is not well studied but is correlated to TRIM24 in breast cancer
|
https://huggingface.co/datasets/fmars/wiki_stem
|
H3K27ac is an epigenetic modification to the DNA packaging protein histone H3. It is a mark that indicates acetylation of the lysine residue at N-terminal position 27 of the histone H3 protein.
H3K27ac is associated with the higher activation of transcription and therefore defined as an active enhancer mark
|
https://huggingface.co/datasets/fmars/wiki_stem
|
H3K27me3 is an epigenetic modification to the DNA packaging protein Histone H3. It is a mark that indicates the tri-methylation of lysine 27 on histone H3 protein.
This tri-methylation is associated with the downregulation of nearby genes via the formation of heterochromatic regions
|
https://huggingface.co/datasets/fmars/wiki_stem
|
H3K36ac is an epigenetic modification to the DNA packaging protein Histone H3. It is a mark that indicates the acetylation at the 36th lysine residue of the histone H3 protein.
H3K36ac has not been widely studied but it is very widely conserved across mammals and yeast and marks genes
|
https://huggingface.co/datasets/fmars/wiki_stem
|
H3K36me is an epigenetic modification to the DNA packaging protein Histone H3, specifically, the mono-methylation at the 36th lysine residue of the histone H3 protein.
There are diverse modifications at H3K36, such as phosphorylation, methylation, acetylation, and ubiquitylation, which have many important biological processes. The methylation of H3K36 has particularly had effects in transcriptional repression, alternative splicing, dosage compensation, DNA replication and repair, DNA methylation, and the transmission of the memory of gene expression from parents to offspring during development
|
https://huggingface.co/datasets/fmars/wiki_stem
|
H3K36me2 is an epigenetic modification to the DNA packaging protein Histone H3. It is a mark that indicates the di-methylation at the 36th lysine residue of the histone H3 protein.
There are diverse modifications at H3K36 and have many important biological processes
|
https://huggingface.co/datasets/fmars/wiki_stem
|
H3K36me3 is an epigenetic modification to the DNA packaging protein Histone H3. It is a mark that indicates the tri-methylation at the 36th lysine residue of the histone H3 protein and often associated with gene bodies.
There are diverse modifications at H3K36 and have many important biological processes
|
https://huggingface.co/datasets/fmars/wiki_stem
|
H3K56ac is an epigenetic modification to the DNA packaging protein Histone H3. It is a mark that indicates the acetylation at the 56th lysine residue of the histone H3 protein.
It is a covalent modification known as a mark of newly replicated chromatin as well as replication-independent histone replacement
|
https://huggingface.co/datasets/fmars/wiki_stem
|
H3K79me2 is an epigenetic modification to the DNA packaging protein Histone H3. It is a mark that indicates the di-methylation at the 79th lysine residue of the histone H3 protein. H3K79me2 is detected in the transcribed regions of active genes
|
https://huggingface.co/datasets/fmars/wiki_stem
|
H3R2me2 is an epigenetic modification to the DNA packaging protein histone H3. It is a mark that indicates the di-methylation at the 2nd arginine residue of the histone H3 protein. In epigenetics, arginine methylation of histones H3 and H4 is associated with a more accessible chromatin structure and thus higher levels of transcription
|
https://huggingface.co/datasets/fmars/wiki_stem
|
H3R8me2 is an epigenetic modification to the DNA packaging protein histone H3. It is a mark that indicates the di-methylation at the 8th arginine residue of the histone H3 protein. In epigenetics, arginine methylation of histones H3 and H4 is associated with a more accessible chromatin structure and thus higher levels of transcription
|
https://huggingface.co/datasets/fmars/wiki_stem
|
H3R17me2 is an epigenetic modification to the DNA packaging protein histone H3. It is a mark that indicates the di-methylation at the 17th arginine residue of the histone H3 protein. In epigenetics, arginine methylation of histones H3 and H4 is associated with a more accessible chromatin structure and thus higher levels of transcription
|
https://huggingface.co/datasets/fmars/wiki_stem
|
H3R26me2 is an epigenetic modification to the DNA packaging protein histone H3. It is a mark that indicates the di-methylation at the 26th arginine residue of the histone H3 protein. In epigenetics, arginine methylation of histones H3 and H4 is associated with a more accessible chromatin structure and thus higher levels of transcription
|
https://huggingface.co/datasets/fmars/wiki_stem
|
H3R42me is an epigenetic modification to the DNA packaging protein histone H3. It is a mark that indicates the mono-methylation at the 42nd arginine residue of the histone H3 protein. In epigenetics, arginine methylation of histones H3 and H4 is associated with a more accessible chromatin structure and thus higher levels of transcription
|
https://huggingface.co/datasets/fmars/wiki_stem
|
H3S10P is an epigenetic modification to the DNA packaging protein histone H3. It is a mark that indicates the phosphorylation the 10th serine residue of the histone H3 protein.
Depending on the environment in which it happens, the same phosphorylated residue might have drastically different consequences on chromatin structure
|
https://huggingface.co/datasets/fmars/wiki_stem
|
H3S28P is an epigenetic modification to the DNA packaging protein histone H3. It is a mark that indicates the phosphorylation the 28th serine residue of the histone H3 protein.
Early mitosis phosphorylation patterns for H3S10 and H3S28 are quite similar, starting at the initiation of chromosomal condensation during prophase
|
https://huggingface.co/datasets/fmars/wiki_stem
|
H3T3P is an epigenetic modification to the DNA packaging protein histone H3. It is a mark that indicates the phosphorylation the 3rd threonine residue of the histone H3 protein.
Pre-existing vs newly generated H3 is distinguished by phosphorylation at threonine 3
|
https://huggingface.co/datasets/fmars/wiki_stem
|
H3T6P is an epigenetic modification to the DNA packaging protein histone H3. It is a mark that indicates the phosphorylation of the 6th threonine residue of the histone H3 protein.
H3S10P and H3T6P levels are higher in cervical cancer cells and are responsible for cellular transformation
|
https://huggingface.co/datasets/fmars/wiki_stem
|
H3T45P is an epigenetic modification to the DNA packaging protein histone H3. It is a mark that indicates the phosphorylation the 45th threonine residue of the histone H3 protein.
During apoptosis, H3T45 phosphorylation is required for structural changes inside the nucleosome that enable DNA nicking and/or fragmentation
|
https://huggingface.co/datasets/fmars/wiki_stem
|
H3Y41P is an epigenetic modification to the DNA packaging protein histone H3. It is a mark that indicates the phosphorylation the 41st tyrosine residue of the histone H3 protein.
To impose cell cycle-dependent regulation of constitutive heterochromatin, H3Y41p collaborates with other regulatory mechanisms
|
https://huggingface.co/datasets/fmars/wiki_stem
|
H4K5ac is an epigenetic modification to the DNA packaging protein histone H4. It is a mark that indicates the acetylation at the 5th lysine residue of the histone H4 protein. H4K5 is the closest lysine residue to the N-terminal tail of histone H4
|
https://huggingface.co/datasets/fmars/wiki_stem
|
H4K8ac, representing an epigenetic modification to the DNA packaging protein histone H4, is a mark indicating the acetylation at the 8th lysine residue of the histone H4 protein. It has been implicated in the prevalence of malaria.
Nomenclature
H4K8ac indicates acetylation of lysine 8 on histone H4 protein subunit:
Histone modifications
The genomic DNA of eukaryotic cells is wrapped around special protein molecules known as histones
|
https://huggingface.co/datasets/fmars/wiki_stem
|
H4K12ac is an epigenetic modification to the DNA packaging protein histone H4. It is a mark that indicates the acetylation at the 12th lysine residue of the histone H4 protein. H4K12ac is involved in learning and memory
|
https://huggingface.co/datasets/fmars/wiki_stem
|
H4K16ac is an epigenetic modification to the DNA packaging protein Histone H4. It is a mark that indicates the acetylation at the 16th lysine residue of the histone H4 protein.
H4K16ac is unusual in that it has both transcriptional activation AND repression activities
|
https://huggingface.co/datasets/fmars/wiki_stem
|
H4K20me is an epigenetic modification to the DNA packaging protein Histone H4. It is a mark that indicates the mono-methylation at the 20th lysine residue of the histone H4 protein. This mark can be di- and tri-methylated
|
https://huggingface.co/datasets/fmars/wiki_stem
|
H4K91ac is an epigenetic modification to the DNA packaging protein histone H4. It is a mark that indicates the acetylation at the 91st lysine residue of the histone H4 protein. No known diseases are attributed to this mark but it might be implicated in melanoma
|
https://huggingface.co/datasets/fmars/wiki_stem
|
H4R3me2 is an epigenetic modification to the DNA packaging protein histone H4. It is a mark that indicates the di-methylation at the 3rd arginine residue of the histone H4 protein. In epigenetics, arginine methylation of histones H3 and H4 is associated with a more accessible chromatin structure and thus higher levels of transcription
|
https://huggingface.co/datasets/fmars/wiki_stem
|
Hard inheritance was a model of heredity that explicitly excludes any acquired characteristics, such as of Lamarckism. It is the exact opposite of soft inheritance, coined by Ernst Mayr to contrast ideas about inheritance.
Hard inheritance states that characteristics of an organism's offspring (passed on through DNA) will not be affected by the actions that the parental organism performs during its lifetime
|
https://huggingface.co/datasets/fmars/wiki_stem
|
The family of heterochromatin protein 1 (HP1) ("Chromobox Homolog", CBX) consists of highly conserved proteins, which have important functions in the cell nucleus. These functions include gene repression by heterochromatin formation, transcriptional activation, regulation of binding of cohesion complexes to centromeres, sequestration of genes to the nuclear periphery, transcriptional arrest, maintenance of heterochromatin integrity, gene repression at the single nucleosome level, gene repression by heterochromatization of euchromatin, and DNA repair. HP1 proteins are fundamental units of heterochromatin packaging that are enriched at the centromeres and telomeres of nearly all eukaryotic chromosomes with the notable exception of budding yeast, in which a yeast-specific silencing complex of SIR (silent information regulatory) proteins serve a similar function
|
https://huggingface.co/datasets/fmars/wiki_stem
|
HIstome is a database that provides information about human histone proteins, their sites of modifications, variants and modifying enzymes, and diseases linked to histone modifications.
Update
HISTome2 is a updated version of the HIstome database released in 2020.
See also
Histone
References
External links
http://www
|
https://huggingface.co/datasets/fmars/wiki_stem
|
In biology, histones are highly basic proteins abundant in lysine and arginine residues that are found in eukaryotic cell nuclei. They act as spools around which DNA winds to create structural units called nucleosomes. Nucleosomes in turn are wrapped into 30-nanometer fibers that form tightly packed chromatin
|
https://huggingface.co/datasets/fmars/wiki_stem
|
Histone acetyltransferases (HATs) are enzymes that acetylate conserved lysine amino acids on histone proteins by transferring an acetyl group from acetyl-CoA to form ε-N-acetyllysine. DNA is wrapped around histones, and, by transferring an acetyl group to the histones, genes can be turned on and off. In general, histone acetylation increases gene expression
|
https://huggingface.co/datasets/fmars/wiki_stem
|
The histone code is a hypothesis that the transcription of genetic information encoded in DNA is in part regulated by chemical modifications (known as histone marks) to histone proteins, primarily on their unstructured ends. Together with similar modifications such as DNA methylation it is part of the epigenetic code. Histones associate with DNA to form nucleosomes, which themselves bundle to form chromatin fibers, which in turn make up the more familiar chromosome
|
https://huggingface.co/datasets/fmars/wiki_stem
|
Histone methylation is a process by which methyl groups are transferred to amino acids of histone proteins that make up nucleosomes, which the DNA double helix wraps around to form chromosomes. Methylation of histones can either increase or decrease transcription of genes, depending on which amino acids in the histones are methylated, and how many methyl groups are attached. Methylation events that weaken chemical attractions between histone tails and DNA increase transcription because they enable the DNA to uncoil from nucleosomes so that transcription factor proteins and RNA polymerase can access the DNA
|
https://huggingface.co/datasets/fmars/wiki_stem
|
Histone methyltransferases (HMT) are histone-modifying enzymes (e. g. , histone-lysine N-methyltransferases and histone-arginine N-methyltransferases), that catalyze the transfer of one, two, or three methyl groups to lysine and arginine residues of histone proteins
|
https://huggingface.co/datasets/fmars/wiki_stem
|
(Histone-H3)-lysine-36 demethylase (EC 1. 14. 11
|
https://huggingface.co/datasets/fmars/wiki_stem
|
Histone-modifying enzymes are enzymes involved in the modification of histone substrates after protein translation and affect cellular processes including gene expression. To safely store the eukaryotic genome, DNA is wrapped around four core histone proteins (H3, H4, H2A, H2B), which then join to form nucleosomes. These nucleosomes further fold together into highly condensed chromatin, which renders the organism's genetic material far less accessible to the factors required for gene transcription, DNA replication, recombination and repair
|
https://huggingface.co/datasets/fmars/wiki_stem
|
Subsets and Splits
No community queries yet
The top public SQL queries from the community will appear here once available.