Aurora

An aurora, sometimes referred to as a polar light, is a natural light display in the sky, predominantly seen in the high latitude (Arctic and Antarctic) regions. Auroras are produced when the magnetosphere is sufficiently disturbed by the solar wind that the trajectories of charged particles in both solar wind and magnetospheric plasma, mainly in the form of electrons and protons, precipitate them into the upper atmosphere (thermosphere/exosphere), where their energy is lost. The resulting ionization and excitation of atmospheric constituents emits light of varying colour and complexity. The form of the aurora, occurring within bands around both polar regions, is also dependent on the amount of acceleration imparted to the precipitating particles. Precipitating protons generally produce optical emissions as incident hydrogen atoms after gaining electrons from the atmosphere. Proton auroras are usually observed at lower latitudes. Different aspects of an aurora are elaborated in various sections below.

Aurora (Turin)

Aurora is an historical district in the city of Turin, Italy. The district includes:

Coordinates: 45°04′59″N 7°41′17″E / 45.08306°N 7.68806°E / 45.08306; 7.68806

Aurora (1984 film)

Aurora is a 1984 Italian drama film directed by Maurizio Ponzi and starring Sophia Loren, Edoardo Ponti and Daniel J. Travanti. In order to raise money for an operation for her son, a woman tells various former wealthy lovers that they are his father. Its Italian title is Qualcosa di biondo.

Plot

A desperate woman (Loren), in crisis and poverty, is in search of the cruel husband (Noiret) who abandoned after giving her a son. The boy has now become almost an adult has a serious eye problem and is likely to become completely blind. The mother then choose to leave to go in search of his father, who in the meantime is starting a new life. When the mother finds out where he is, also learns that the cruel man has remade a family by marrying a young girl, who became the mother of a twenty-year-old son who has had the cruel man from another relationship.

Cast

Sulfonylurea receptor

In the field of molecular biology, the sulfonylurea receptors (SUR) are membrane proteins which are the molecular targets of the sulfonylurea class of antidiabetic drugs whose mechanism of action is to promote insulin release from pancreatic beta cells. More specifically, SUR proteins are subunits of the inward-rectifier potassium ion channels K_ir6.x (6.1 and 6.2). The association of four K_ir6.x and four SUR subunits form an ion conducting channel commonly referred to as the K_ATP channel.

There are three forms of the sulfonylurea receptor, SUR1 encoded by the ABCC8 gene and SUR2A and SUR2B which are splice variants arising from a single ABCC9 gene.

Function

The primary function of the sulfonylurea receptor is to sense intracellular levels of the nucleotides ATP and ADP and in response facilitate the open or closing its associated K_ir6.x potassium channel. Hence the K_ATP channel monitors the energy balance within the cell.

Depending on the tissue in which the K_ATP channel is expressed, altering the membrane potential can trigger a variety of down stream events. For example, in pancreatic beta cells, high levels of glucose lead to increased production of ATP which in turn binds to the K_ATP channel resulting in channel closure. The increase in membrane potential in turn opens voltage-dependent calcium channels increasing intracellular calcium concentrations which triggers exocytosis of insulin.