polis

Examples of polis in the following topics:

• Archaic Greece

  • The Archaic Period saw the increasing urbanization of Greek communities, and the development of the concept of the polis.
  • The period began with a massive increase in the Greek population and a structural revolution that established the Greek city-states, or polis.
  • The Archaic period saw significant urbanization and the development of the concept of the polis as it was used in classical Greece.
  • However, the polis did not become the dominant form of sociopolitical organization throughout Greece during the Archaic period, and in the north and west of the country it did not become dominant until later in the classical period.
  • The increase in population, and evolution of the polis as a sociopolitical structure, necessitated a new form of political organization.

• mRNA Processing

  • Eukaryotic pre-mRNA receives a 5' cap and a 3' poly (A) tail before introns are removed and the mRNA is considered ready for translation.
  • An enzyme called poly (A) polymerase (PAP) is part of the same protein complex that cleaves the pre-mRNA and it immediately adds a string of approximately 200 A nucleotides, called the poly (A) tail, to the 3' end of the just-cleaved pre-mRNA.
  • The poly (A) tail protects the mRNA from degradation, aids in the export of the mature mRNA to the cytoplasm, and is involved in binding proteins involved in initiating translation.
  • Poly (A) Polymerase adds a 3' poly (A) tail to the pre-mRNA.
  • Immediately after the cleavage, Poly (A) Polymerase (PAP), which is also part of the protein complex, catalyzes the addition of up to 200 A nucleotides to the 3' end of the just-cleaved pre-mRNA.

• Bacterial Polyesters

  • The resulting PHA is of the two types: Poly (HA SCL) from hydroxy fatty acids with short chain lengths including three to five carbon atoms are synthesized by numerous bacteria, including Ralstonia eutropha and Alcaligenes latus (PHB).
  • Poly (HA MCL) from hydroxy fatty acids with middle chain lengths including six to 14 carbon atoms, can be made for example, by Pseudomonas putida.
  • The simplest and most commonly occurring form of PHA is the fermentative production of poly-beta-hydroxybutyrate) (poly-3-hydroxybutyrate, P3HB), which consists of 1000 to 30000 hydroxy fatty acid monomers.
  • A PHA copolymer called PHBV (poly(3-hydroxybutyrate-co-3-hydroxyvalerate)) is less stiff and tougher, and it may be used as packaging material.

• Polymers

  • The terms polymer and monomer were derived from the Greek roots poly (many), mono (one) and meros (part).

• Addition Copolymerization

  • However, the product of cationic polymerization is largely polystyrene, and anionic polymerization favors formation of poly(methyl methacrylate).

• Condensation Polymers

  • Examples of naturally occurring condensation polymers are cellulose, the polypeptide chains of proteins, and poly(β-hydroxybutyric acid), a polyester synthesized in large quantity by certain soil and water bacteria.

• Biodegradable Polymers

  • PLA is actually a polymer of lactic acid, but the dimeric lactide is used as the precursor to avoid the water that would be formed in a direct poly-esterification.
  • Poly-L-lactide (PLLA) is the product resulting from polymerization of (S,S)-lactide.
  • The melting temperature of PLLA can be increased 40-50 ºC and its heat deformation temperature can be increased from approximately 60 ºC to up to 190 ºC by physically blending the polymer with PDLA (poly-D-lactide).
  • The simplest and most commonly occurring form of PHA is poly (R-3-hydroxybutyrate), PHB or P(3HB)).

• The Rise of Classical Greece

  • The term "city-state," which is English in origin, does not fully translate the Greek term for these same entities, polis.
  • Basic elements of a polis often included the following:
  • Polis were established and expanded by synoecism, or the absorption of nearby villages and tribes.
  • Territory was a less helpful means of thinking about the shape of a polis than regions of shared religious and political associations.
  • Dwellers of a polis were typically divided into four separate social classes, with an individual’s status usually being determined at birth.

• Temperate Forests

  • The leaf litter also protects soil from erosion, insulates the ground, and provides habitats for invertebrates (such as the pill bug or roly-poly, Armadillidium vulgare) and their predators, such as the red-backed salamander (Plethodon cinereus).
  • The leaf litter is home to invertebrates (such as the pill bug or roly-poly, Armadillidium vulgare) and their predators, including the red-backed salamander (Plethodon cinereus).

• Types of Biological Macromolecules

  • The prefixes "mono-" (one), "di-" (two),and "poly-" (many) will tell you how many of the monomers have been joined together in a molecule.
  • The small molecular units are called monomers (mono means one, or single), and they are linked together into long chains called polymers (poly means many, or multiple).