Boron ( /ˈbɔərɒn/) is the chemical element with atomic number 5 and the chemical symbol B. Because boron is produced entirely by cosmic ray spallation and not by stellar nucleosynthesis, it is a low-abundance element in both the solar system and the Earth's crust. However, boron is concentrated on Earth by the water-solubility of its more common naturally occurring compounds, the borate minerals. These are mined industrially as evaporate ores, such as borax and kernite.

Chemically uncombined boron, which is classed as a metalloid, is not found naturally on Earth. Industrially, very pure boron is produced with difficulty, as boron tends to form refractory materials containing small amounts of carbon or other elements. Several allotropes of boron exist: amorphous boron is a brown powder and crystalline boron is black, extremely hard (about 9.5 on Mohs' scale), and a poor conductor at room temperature. Elemental boron is used as a dopant in the semiconductor industry.

The major industrial-scale uses of boron compounds are in sodium perborate bleaches, and the borax component of fiberglass insulation. Boron polymers and ceramics play specialized roles as high-strength lightweight structural and refractory materials. Boron compounds are used in silica-based glasses and ceramics to give them resistance to thermal shock. Boron-containing reagents are used for as intermediates in the synthesis of organic fine chemicals. A few boron-containing organic pharmaceuticals are used, or are in study. Natural boron is composed of two stable isotopes, one of which (boron-10) has a number of uses as a neutron-capturing agent.

Robert de Boron (also spelled in the manuscripts "Bouron", "Beron") was a French poet of the late 12th and early 13th centuries who is most notable as the author of the poems Joseph d'Arimathe and Merlin.

Robert de Boron was the author of two surviving poems in octosyllabic verse, the Grail story Joseph d'Arimathe and Merlin. The latter work survives only in fragments and in later versions rendered in prose. The two poems are thought to have formed either a trilogy - with a verse Perceval forming the third part - or a tetralogy - with Perceval a Mort Artu (Death of Arthur). The "Didot Perceval", a retelling of the Percival story similar in style and content to Robert's other works, may be a prosification of the lost sections.

Robert de Boron is the first author to give the Holy Grail myth an explicitly Christian dimension. According to him, Joseph of Arimathea used the Grail (the Last Supper vessel) to catch the last drops of blood from Jesus's body as he hung on the cross. Joseph's family brought the Grail to the vaus d'Avaron, the valleys of Avaron in the west, which later poets changed to Avalon, identified with Glastonbury, where they guarded it until the rise of King Arthur and the coming of Perceval. Robert also introduced a "Rich Fisher" variation on the Fisher King.

Antonio Gramsci (Italian pronunciation: [anˈtɔːnjo ˈɡramʃi]) (January 22, 1891 – April 27, 1937) was an Italian writer, politician, political theorist, and linguist. He was a founding member and onetime leader of the Communist Party of Italy and was imprisoned by Benito Mussolini's Fascist regime.

Gramsci was one of the most important Marxist thinkers in the 20th century. His writings are heavily concerned with the analysis of culture and political leadership and he is notable as a highly original thinker within modern European thought. He is renowned for his concept of cultural hegemony as a means of maintaining the state in a capitalist society.

Gramsci was born in Ales, on the island of Sardinia. He was the fourth of seven sons of Francesco Gramsci (1860–1937), a low-level official from Gaeta, and his wife, Giuseppina Marcias (1861–1932). Gramsci's father was of Arbëreshë, Albanian descent, while his mother belonged to a local landowning family. The senior Gramsci's financial difficulties and troubles with the police forced the family to move about through several villages in Sardinia until they finally settled in Ghilarza.