Locus (mathematics)

In geometry, a locus (plural: loci) (Latin word for "place", "location") is a set of points (commonly, a line, a line segment, a curve or a surface), whose location satisfies or is determined by one or more specified conditions.

History and philosophy

Until the beginning of 20th century, a geometrical shape (for example a curve) was not considered as an infinite set of points; rather, it was considered as an entity on which a point may be located or on which it moves. Thus a circle in the Euclidean plane was defined as the locus of a point that is at a given distance of a fixed point, the center of the circle. In modern mathematics, similar concepts are more frequently reformulated by describing shapes as sets; for instance, one says that the circle is the set of points that are at a given distance of the center. In contrast to the set-theoretic view, the old formulation avoids considering infinite collections, as avoiding the actual infinite was an important philosophical position of earlier mathematicians.

! (disambiguation)

! is a punctuation mark called an exclamation mark (33 in ASCII), exclamation point, ecphoneme, or bang.

! may also refer to:

Mathematics and computers

Music

Other

See also

Junior Certificate

The Junior Certificate (Irish: Teastas Sóisearach) is an educational qualification awarded in Ireland by the Department of Education and Skills to students who have successfully completed the junior cycle of secondary education, and achieved a minimum standard in their Junior Certification examinations. These exams, like those for the Leaving Certificate, are supervised by the State Examinations Commission. A "recognised pupil"<ref name"">Definitions, Rules and Programme for Secondary Education, Department of Education, Ireland, 2004</ref> who commences the Junior Cycle must reach at least 12 years of age on 1 January of the school year of admission and must have completed primary education; the examination is normally taken after three years' study in a secondary school. Typically a student takes 9 to 13 subjects – including English, Irish and Mathematics – as part of the Junior Cycle. The examination does not reach the standards for college or university entrance; instead a school leaver in Ireland will typically take the Leaving Certificate Examination two or three years after completion of the Junior Certificate to reach that standard.

The Servant (band)

The Servant was an English alternative band, formed in London in 1998. They are popular in France, Spain, Switzerland as well as other European countries.

Their first introduction to an American audience was in the trailer of the film Sin City with the instrumental version of their song "Cells". This version of "Cells" is not on the Sin City soundtrack, but it can be downloaded via their website ("Cells" was also used in the film The Transporter and Transporter 2, along with their song, "Body"). Since the Sin City trailers, there has been significant U.S. interest in their records and demands for live concerts. The band released their fourth album entitled How To Destroy A Relationship in 2006.

Before achieving commercial success in 2004 with their self-titled album, released by Prolifica Records in the UK and by Recall Group in France, The Servant released two EP's: Mathematics in 1999 and With the Invisible in 2000.

On 26 November 2007, the band announced on their blog at MySpace that they were splitting up "to move on to pastures new".

Locus

The word locus (plural loci) is Latin for "place". It may refer to:

Positions

Acronyms

Periodicals

Other uses

Locus (genetics)

A locus (plural loci), in genetics, is the specific location or position of a gene, DNA sequence, on a chromosome. Each chromosome carries many genes; humans' estimated 'haploid' protein coding genes are 20,000-25,000, on the 23 different chromosomes. A variant of the similar DNA sequence located at a given locus is called an allele. The ordered list of loci known for a particular genome is called a gene map. Gene mapping is the process of determining the locus for a particular biological trait.

Diploid and polyploid cells whose chromosomes have the same allele of a given gene at some locus are called homozygous with respect to that gene, while those that have different alleles of a given gene at a locus, are called heterozygous with respect to that gene.

Nomenclature

The chromosomal locus of a gene might be written "6p21.3". Because "21" refers to "region 2, band 1" this is read as "two one", not as "twenty-one". So the entire locus is "six P two one point three."

A range of loci is specified in a similar way. For example, the locus of gene OCA1 may be written "11q1.4-q2.1", meaning it is on the long arm of chromosome 11, somewhere in the range from sub-band 4 of region 1 to sub-band 1 of region 2.

Transmission (medicine)

In medicine and biology, transmission is the passing of a communicable disease from an infected host individual or group to a particular individual or group, regardless of whether the other individual was previously infected.

The term usually refers to the transmission of microorganisms directly from one individual to another by one or more of the following means:

Transmission can also be indirect, via another organism, either a vector (e.g. a mosquito or fly) or an intermediate host (e.g. tapeworm in pigs can be transmitted to humans who ingest improperly cooked pork). Indirect transmission could involve zoonoses or, more typically, larger pathogens like macroparasites with more complex life cycles.