The numerical value of true in many programming languages. 1 is the ASCII code of "Start of Header". In science
Dimensionless quantities are also known as quantities of dimension one. 1 is the atomic number of hydrogen. +1 is the electric charge of positrons and protons. Group 1 of the periodic table consists of the alkali metals. Period 1 of the periodic table consists of just two elements, hydrogen and helium. The dwarf planet Ceres has the minor-planet designation 1 Ceres because it was the first asteroid to be discovered. The Roman numeral I often stands for the first-discovered satellite of a planet or minor planet (such as Neptune I, a.k.a. Triton). For some earlier discoveries, the Roman numerals originally reflected the increasing distance from the primary instead. In philosophy
In the philosophy of Plotinus (and that of other neoplatonists), The One is the ultimate reality and source of all existence. Philo of Alexandria (20 BC – AD 50) regarded the number one as Gods number, and the basis for all numbers ("De Allegoriis Legum," ii.12 [i.66]). The Neopythagorean philosopher Nicomachus of Gerasa affirmed that one is not a number, but the source of number. He also believed the number two is the embodiment of the origin of otherness. His number theory was recovered by Boethius in his Latin translation of Nicomachuss treatise Introduction to Arithmetic.
Pathogen
The genus includes a number of economically important plant pathogenic species. Fusarium graminearum commonly infects barley if there is rain late in the season. It is of economic impact to the malting and brewing industries, as well as feed barley. Fusarium contamination in barley can result in head blight, and in extreme contaminations, the barley can appear pink. The genome of this wheat and maize pathogen has been sequenced. F. graminearum can also cause root rot and seedling blight. The total losses in the US of barley and wheat crops between 1991 and 1996 have been estimated at $3 billion.Fusarium oxysporum f.sp. cubense is a fungal plant pathogen that causes Panama disease of banana (Musa spp. ), also known as fusarium wilt of banana. Panama disease affects a wide range of banana cultivars, which are propagated asexually from offshoots and therefore have very little genetic diversity. Panama disease is one of the most destructive plant diseases of modern times, and caused the commercial disappearance of the once dominant Gros Michel cultivar. A more recent strain also affects the Cavendish cultivars which commercially replaced Gros Michel. It is considered inevitable that this susceptibility will spread globally and commercially wipe out the Cavendish cultivar, for which there are currently no acceptable replacements. Fusarium oxysporum f. sp. narcissi causes rotting of the bulbs (basal rot) and yellowing of the leaves of daffodils (Narcissi).