Summary

HandWiki is the world's largest wiki-style encyclopedia dedicated to science, technology and computing. It allows you to create and edit articles as long as you have external citations and login account. In addition, this is a content management environment that can be used for collaborative editing of original scholarly content, such as books, manuals, monographs and tutorials.

Expand All
Entries
Topic Review
Experimental Economics
Experimental economics is the application of experimental methods to study economic questions. Data collected in experiments are used to estimate effect size, test the validity of economic theories, and illuminate market mechanisms. Economic experiments usually use cash to motivate subjects, in order to mimic real-world incentives. Experiments are used to help understand how and why markets and other exchange systems function as they do. Experimental economics have also expanded to understand institutions and the law (experimental law and economics). A fundamental aspect of the subject is design of experiments. Experiments may be conducted in the field or in laboratory settings, whether of individual or group behavior. Variants of the subject outside such formal confines include natural and quasi-natural experiments.
  • 1.2K
  • 31 Oct 2022
Topic Review
Hedgehogs in Culture
Hedgehogs have appeared widely in popular and folk culture.
  • 2.1K
  • 31 Oct 2022
Topic Review
Extractive Industries Transparency Initiative
The Extractive Industries Transparency Initiative (EITI) is a global standard for the good governance of oil, gas and mineral resources. It seeks to address the key governance issues in the extractive sectors. The EITI Standard requires information along the extractive industry value chain from the point of extraction, to how the revenue makes its way through the government and its contribution to the economy. This includes how licenses and contracts are allocated and registered, who the beneficial owners of those operations are, what the fiscal and legal arrangements are, how much is produced, how much is paid, where the revenue is allocated, and its contributions to the economy, including employment. The EITI Standard is implemented in 52 countries around the world. Each of these countries is required to publish an annual EITI Report to disclosing information on: contracts and licenses, production, revenue collection, revenue allocation, and social and economic spending. Every country goes through a quality-assurance mechanism, called Validation, at least every three years. Validation serves to assess performance towards meeting the EITI Standard and promote dialogue and learning at the country level. It also safeguards the integrity of the EITI by holding all EITI implementing countries to the same global standard. Each implementing country has its own national secretariat and multi-stakeholder group made up of representatives from the country’s government, extractive companies and civil society. The multi-stakeholder group takes decisions on how the EITI process is carried out in the country. The EITI Standard is developed and overseen by an international multi-stakeholder Board, consisting of representatives from governments, extractives companies, civil society organisations, financial institutions and international organisations. The current Chair of the EITI is Fredrik Reinfeldt, former Prime Minister of Sweden. The previous chairs have been Clare Short (2011-2016), former UK Secretary of State for International Development and Peter Eigen (2009-2011). The EITI International Secretariat is located in Oslo, Norway and is headed by Eddie Rich.
  • 1.7K
  • 31 Oct 2022
Topic Review
Living Anionic Polymerization
Living anionic polymerization is a living polymerization technique involving an anionic propagating species. Living anionic polymerization was demonstrated by Szwarc and co workers in 1956. Their initial work was based on the polymerization of styrene and dienes. One of the remarkable features of living anionic polymerization is that the mechanism involves no formal termination step. In the absence of impurities, the carbanion would still be active and capable of adding another monomer. The chains will remain active indefinitely unless there is inadvertent or deliberate termination or chain transfer. This gave rise to two important consequences: The following experimental criteria have been proposed as a tool for identifying a system as living polymerization system. However, in practice, even in the absence of terminating agents, the concentration of the living anions will reduce with time due to a decay mechanism termed as spontaneous termination.
  • 2.8K
  • 31 Oct 2022
Topic Review
Fitness
Fitness (often denoted [math]\displaystyle{ w }[/math] or ω in population genetics models) is the quantitative representation of individual reproductive success. It is also equal to the average contribution to the gene pool of the next generation, made by the same individuals of the specified genotype or phenotype. Fitness can be defined either with respect to a genotype or to a phenotype in a given environment or time. The fitness of a genotype is manifested through its phenotype, which is also affected by the developmental environment. The fitness of a given phenotype can also be different in different selective environments. With asexual reproduction, it is sufficient to assign fitnesses to genotypes. With sexual reproduction, recombination scrambles alleles into different genotypes every generation; in this case, fitness values can be assigned to alleles by averaging over possible genetic backgrounds. Natural selection tends to make alleles with higher fitness more common over time, resulting in Darwinian evolution. The term "Darwinian fitness" can be used to make clear the distinction with physical fitness. Fitness does not include a measure of survival or life-span; Herbert Spencer's well-known phrase "survival of the fittest" should be interpreted as: "Survival of the form (phenotypic or genotypic) that will leave the most copies of itself in successive generations." Inclusive fitness differs from individual fitness by including the ability of an allele in one individual to promote the survival and/or reproduction of other individuals that share that allele, in preference to individuals with a different allele. One mechanism of inclusive fitness is kin selection.
  • 1.7K
  • 31 Oct 2022
Topic Review
Chöd
Chöd (Tibetan: གཅོད, Wylie: gcod lit. 'to sever'), is a spiritual practice found primarily in the Nyingma and Kagyu schools of Tibetan Buddhism (where it is classed as Anuttarayoga Tantra). Also known as "Cutting Through the Ego,", the practices are based on the Prajñāpāramitā or "Perfection of Wisdom" sutras, which expound the "emptiness" concept of Buddhist philosophy. According to Mahayana Buddhists, emptiness is the ultimate wisdom of understanding that all things lack inherent existence. Chöd combines prajñāpāramitā philosophy with specific meditation methods and tantric ritual. The chod practitioner seeks to tap the power of fear through activities such as rituals set in graveyards, and visualisation of offering their bodies in a tantric feast in order to put their understanding of emptiness to the ultimate test.
  • 1.2K
  • 31 Oct 2022
Topic Review
Transmission Electron Microscopy DNA Sequencing
Transmission electron microscopy DNA sequencing is a single-molecule sequencing technology that uses transmission electron microscopy techniques. The method was conceived and developed in the 1960s and 70s, but lost favor when the extent of damage to the sample was recognized. In order for DNA to be clearly visualized under an electron microscope, it must be labeled with heavy atoms. In addition, specialized imaging techniques and aberration corrected optics are beneficial for obtaining the resolution required to image the labeled DNA molecule. In theory, transmission electron microscopy DNA sequencing could provide extremely long read lengths, but the issue of electron beam damage may still remain and the technology has not yet been commercially developed.
  • 1.8K
  • 31 Oct 2022
Topic Review
Badlands National Park
Badlands National Park is an American national park located in southwestern South Dakota. The park protects 242,756 acres (379.306 sq mi; 98,240 ha) of sharply eroded buttes and pinnacles, along with the largest undisturbed mixed grass prairie in the United States. The National Park Service manages the park, with the South Unit being co-managed with the Oglala Lakota tribe. The Badlands Wilderness protects 64,144 acres (100.225 sq mi; 25,958 ha) of the park as a designated wilderness area, and is one site where the black-footed ferret, one of the most endangered mammals in the world, was reintroduced to the wild. The South Unit, or Stronghold District, includes sites of 1890s Ghost Dances, a former United States Air Force bomb and gunnery range, and Red Shirt Table, the park's highest point at 3,340 feet (1,020 m). Authorized as Badlands National Monument on March 4, 1929, it was not established until January 25, 1939. Badlands was redesignated a national park on November 10, 1978. Under the Mission 66 plan, the Ben Reifel Visitor Center was constructed for the monument in 1957–58. The park also administers the nearby Minuteman Missile National Historic Site. Movies such as Dances with Wolves (1990) and Thunderheart (1992) were partially filmed in Badlands National Park.
  • 991
  • 31 Oct 2022
Topic Review
Intel Active Management Technology
Intel Active Management Technology (AMT) is hardware and firmware for remote out-of-band management of select business computers, running on the Intel Management Engine, a microprocessor subsystem not exposed to the user, in order to monitor, maintain, update, upgrade and repair them. Out-of-band (OOB) or hardware-based management is different from software-based (or in-band) management and software management agents. Hardware-based management works at a different level from software applications, and uses a communication channel (through the TCP/IP stack) that is different from software-based communication (which is through the software stack in the operating system). Hardware-based management does not depend on the presence of an OS or locally installed management agent. Hardware-based management has been available on Intel/AMD based computers in the past, but it has largely been limited to auto-configuration using DHCP or BOOTP for dynamic IP address allocation and diskless workstations, as well as wake-on-LAN (WOL) for remotely powering on systems. AMT is not intended to be used by itself; it is intended to be used with a software management application. It gives a management application (and thus, the system administrator who uses it) access to the PC down the wire, in order to remotely do tasks that are difficult or sometimes impossible when working on a PC that does not have remote functionalities built into it. AMT is designed into a service processor located on the motherboard, and uses TLS-secured communication and strong encryption to provide additional security. AMT is built into PCs with Intel vPro technology and is based on the Intel Management Engine (ME). AMT has moved towards increasing support for DMTF Desktop and mobile Architecture for System Hardware (DASH) standards and AMT Release 5.1 and later releases are an implementation of DASH version 1.0/1.1 standards for out-of-band management. AMT provides similar functionality to IPMI, although AMT is designed for client computing systems as compared with the typically server-based IPMI. Currently, AMT is available in desktops, servers, ultrabooks, tablets, and laptops with Intel Core vPro processor family, including Intel Core i5, Core i7, Core i9 and Intel Xeon E3-1000, Xeon E, Xeon W-1000 product family. Intel confirmed a Remote Elevation of Privilege bug (CVE-2017-5689, SA-00075) in its Management Technology on May 1, 2017. Every Intel platform with either Intel Standard Manageability, Active Management Technology, or Small Business Technology, from Nehalem in 2008 to Kaby Lake in 2017 has a remotely exploitable security hole in the ME. Some manufacturers, like Purism and System76 are already selling hardware with Intel Management Engine disabled to prevent the remote exploit. Additional major security flaws in the ME affecting a very large number of computers incorporating Management Engine, Trusted Execution Engine, and Server Platform Services firmware, from Skylake in 2015 to Coffee Lake in 2017, were confirmed by Intel on November 20, 2017 (SA-00086).
  • 2.7K
  • 31 Oct 2022
Topic Review
Hyperpolarization
Hyperpolarization is the nuclear spin polarization of a material in a magnetic field far beyond thermal equilibrium conditions determined by the Boltzmann distribution. It can be applied to gases such as 129Xe and 3He, and small molecules where the polarization levels can be enhanced by a factor of 104-105 above thermal equilibrium levels. Hyperpolarized noble gases are typically used in magnetic resonance imaging (MRI) of the lungs. Hyperpolarized small molecules are typically used for in vivo metabolic imaging. For example, a hyperpolarized metabolite can be injected into animals or patients and the metabolic conversion can be tracked in real-time. Other applications include determining the function of the neutron spin-structures by scattering polarized electrons from a very polarized target (3He), surface interaction studies, and neutron polarizing experiments.
  • 1.7K
  • 03 Nov 2022
  • Page
  • of
  • 863

Other Entry Collections

>>