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Multi-access Key
In biology or medicine, a multi-access key is an identification key which overcomes the problem of the more traditional single-access keys (dichotomous or polytomous identification keys) of requiring a fixed sequence of identification steps. A multi-access key enables the user to freely choose the characteristics that are convenient to evaluate for the item to be identified.Pankhurst, R. J. 1991. Practical Taxonomic Computing.Winston, J. 1999. Describing Species. Columbia University Press. Alternative terms Alternative terms used for multi-access keys are "random-access key", "multi-entry key", "polyclave", "matrix key", "tabular key", "synoptic key". Some of these terms should be avoided in this sense, however: * "Multi-entry" keys allow the free choice of characters only in the first step, whereas in a typical multi-access key the choice of characters used for identification can be repeated multiple times (reducing the number of remaining taxa each time). The single step of s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Identification Key
In biology, an identification key, taxonomic key, or frequently just key, is a printed or computer-aided device that aids in the identification of biological organisms. Historically, the most common type of identification key is the dichotomous key, a type of single-access key which offers a fixed sequence of identification steps, each with two alternatives. The earliest examples of identification keys originate in the seventeenth, but their conceptual history can be traced back to antiquity. Modern multi-access keys allow the user to freely choose the identification steps and any order. They were traditionally performed using punched cards but now almost exclusively take the form of computer programs. History The conceptual origins of the modern identification key can be traced back to antiquity. Theophrastus categorized organisms into "subdivisions" based on dichotomous characteristics. The seventeenth-century Chinese herbalist, Pao Shan, in his treatise ''Yeh-ts'ai Po-Iu'' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Biology
Biology is the scientific study of life and living organisms. It is a broad natural science that encompasses a wide range of fields and unifying principles that explain the structure, function, growth, History of life, origin, evolution, and distribution of life. Central to biology are five fundamental themes: the cell (biology), cell as the basic unit of life, genes and heredity as the basis of inheritance, evolution as the driver of biological diversity, energy transformation for sustaining life processes, and the maintenance of internal stability (homeostasis). Biology examines life across multiple biological organisation, levels of organization, from molecules and cells to organisms, populations, and ecosystems. Subdisciplines include molecular biology, physiology, ecology, evolutionary biology, developmental biology, and systematics, among others. Each of these fields applies a range of methods to investigate biological phenomena, including scientific method, observation, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Medicine
Medicine is the science and Praxis (process), practice of caring for patients, managing the Medical diagnosis, diagnosis, prognosis, Preventive medicine, prevention, therapy, treatment, Palliative care, palliation of their injury or disease, and Health promotion, promoting their health. Medicine encompasses a variety of health care practices evolved to maintain and restore health by the prevention (medical), prevention and treatment of illness. Contemporary medicine applies biomedical sciences, biomedical research, medical genetics, genetics, and medical technology to diagnosis (medical), diagnose, treat, and prevent injury and disease, typically through pharmaceuticals or surgery, but also through therapies as diverse as psychotherapy, splint (medicine), external splints and traction, medical devices, biologic medical product, biologics, and Radiation (medicine), ionizing radiation, amongst others. Medicine has been practiced since Prehistoric medicine, prehistoric times, and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Single-access Key
In phylogenetics, a single-access key (also called dichotomous key, sequential key, analytical key, or pathway key) is an identification key where the sequence and structure of identification steps is fixed by the author of the key. At each point in the decision process, multiple alternatives are offered, each leading to a result or a further choice. The alternatives are commonly called "leads", and the set of leads at a given point a "couplet". Single access keys are closely related to decision trees and binary search trees. However, to improve the usability and reliability of keys, many single-access keys incorporate reticulation, changing the tree structure into a directed acyclic graph. Single-access keys have been in use for several hundred years. They may be printed in various styles (e. g., linked, nested, indented, graphically branching) or used as interactive, computer-aided keys. In the latter case, either a longer part of the key may be displayed (optionally hyperl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dichotomy
A dichotomy () is a partition of a set, partition of a whole (or a set) into two parts (subsets). In other words, this couple of parts must be * jointly exhaustive: everything must belong to one part or the other, and * mutually exclusive: nothing can belong simultaneously to both parts. If there is a concept A, and it is split into parts B and not-B, then the parts form a dichotomy: they are mutually exclusive, since no part of B is contained in not-B and vice versa, and they are jointly exhaustive, since they cover all of A, and together again give A. Such a partition is also frequently called a bipartition. The two parts thus formed are Complement (set theory), complements. In logic, the partitions are dual (category theory), opposites if there exists a proposition such that it holds over one and not the other. Treating continuous variables or multicategorical variables as binary variables is called discretization, dichotomization. The discretization error inherent in dichoto ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Polytomy
An internal node of a phylogenetic tree is described as a polytomy or multifurcation if (i) it is in a rooted tree and is linked to three or more child subtrees or (ii) it is in an unrooted tree and is attached to four or more branches. A tree that contains any multifurcations can be described as a multifurcating tree. Soft polytomies vs. hard polytomies Two types of polytomies are recognized, soft and hard polytomies. Soft polytomies are the result of insufficient phylogenetic information: though the lineages diverged at different times – meaning that some of these lineages are closer relatives than others, and the available data does not allow recognition of this. Most polytomies are soft, meaning that they would be resolved into a typical tree of dichotomies if better data were available. In contrast, a hard polytomy represents a true divergence event of three or more lineages. Applications Interpretations for a polytomy depend on the individuals that are represented ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Identification (biology)
Identification in biology is the process of assigning a pre-existing taxon name to an individual organism. Identification of organisms to individual scientific names (or codes) may be based on individualistic natural body features, experimentally created individual markers (e.g., color dot patterns), or natural individualistic molecular markers (similar to those used in maternity or paternity identification tests). Individual identification is used in ecology, wildlife management and conservation biology. The more common form of identification is the identification of organisms to common names (e. g., "lion") or scientific name (e. g., "''Panthera leo''"). By necessity this is based on inherited features ("characters") of the sexual organisms, the inheritance forming the basis of defining a class. The features may, e. g., be morphological, anatomical, physiological, behavioral, or molecular. The term "determination" may occasionally be used as a synonym for identification (e. g.) ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Taxon
In biology, a taxon (back-formation from ''taxonomy''; : taxa) is a group of one or more populations of an organism or organisms seen by taxonomists to form a unit. Although neither is required, a taxon is usually known by a particular name and given a particular ranking, especially if and when it is accepted or becomes established. It is very common, however, for taxonomists to remain at odds over what belongs to a taxon and the criteria used for inclusion, especially in the context of rank-based (" Linnaean") nomenclature (much less so under phylogenetic nomenclature). If a taxon is given a formal scientific name, its use is then governed by one of the nomenclature codes specifying which scientific name is correct for a particular grouping. Initial attempts at classifying and ordering organisms (plants and animals) were presumably set forth in prehistoric times by hunter-gatherers, as suggested by the fairly sophisticated folk taxonomies. Much later, Aristotle, and later st ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Species
A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of Taxonomy (biology), classification and a taxonomic rank of an organism, as well as a unit of biodiversity. Other ways of defining species include their karyotype, DNA sequence, morphology (biology), morphology, behaviour, or ecological niche. In addition, palaeontologists use the concept of the chronospecies since fossil reproduction cannot be examined. The most recent rigorous estimate for the total number of species of eukaryotes is between 8 and 8.7 million. About 14% of these had been described by 2011. All species (except viruses) are given a binomial nomenclature, two-part name, a "binomen". The first part of a binomen is the name of a genus to which the species belongs. The second part is called the specific name (zoology), specific name or the specific ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Table (information)
A table is an arrangement of information or data, typically in rows and columns, or possibly in a more complex structure. Tables are widely used in communication, research, and data analysis. Tables appear in print media, handwritten notes, computer software, architectural ornamentation, traffic signs, and many other places. The precise conventions and terminology for describing tables vary depending on the context. Further, tables differ significantly in variety, structure, flexibility, notation, representation and use. Information or data conveyed in table form is said to be in tabular format (adjective). In books and technical articles, tables are typically presented apart from the main text in numbered and captioned floating blocks. Basic description A table consists of an ordered arrangement of rows and columns. This is a simplified description of the most basic kind of table. Certain considerations follow from this simplified description: * the term row has several ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Taxonomy (biology)
In biology, taxonomy () is the science, scientific study of naming, defining (Circumscription (taxonomy), circumscribing) and classifying groups of biological organisms based on shared characteristics. Organisms are grouped into taxon, taxa (singular: taxon), and these groups are given a taxonomic rank; groups of a given rank can be aggregated to form a more inclusive group of higher rank, thus creating a taxonomic hierarchy. The principal ranks in modern use are domain (biology), domain, kingdom (biology), kingdom, phylum (''division'' is sometimes used in botany in place of ''phylum''), class (biology), class, order (biology), order, family (biology), family, genus, and species. The Swedish botanist Carl Linnaeus is regarded as the founder of the current system of taxonomy, having developed a ranked system known as Linnaean taxonomy for categorizing organisms. With advances in the theory, data and analytical technology of biological systematics, the Linnaean system has transfo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Punched Card
A punched card (also punch card or punched-card) is a stiff paper-based medium used to store digital information via the presence or absence of holes in predefined positions. Developed over the 18th to 20th centuries, punched cards were widely used for data processing, the control of automated machines, and computing. Early applications included controlling weaving looms and recording census data. Punched cards were widely used in the 20th century, where unit record equipment, unit record machines, organized into data processing systems, used punched cards for Input (computer science), data input, data output, and data storage. The IBM 12-row/80-column punched card format came to dominate the industry. Many early digital computers used punched cards as the primary medium for input of both computer programs and Data (computing), data. Punched cards were used for decades before being replaced by magnetic storage and terminals. Their influence persists in cultural references, sta ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
