Turcja - korytarz transzytowy dla surocow energetycznych do UE? Prace OSW 17/2005. = Turkey - an energy transit corridor to the EU? OSW Study 17/2005

1. The priority of Ankara's energy policy is to make Turkey an important transit corridor for energy resources transported to the EU. Turkey wishes to play an active role in the distribution and sale of gas and oil flowing across its territory. 2. Transit and sale of energy resources, and gas in particular, are expected to provide a major source of income for Turkey and a tool by which Ankara will be able to build its position in the region and in Europe. 3. Since Turkey is an EU candidate country, Brussels will probably welcome Turkey's role as a transit corridor as much as Ankara will. 4. The success of Ankara's energy strategy hinges on developments in Turkey's internal energy market. 5. It also depends on a number of external factors including: - Export policies and internal situation in producer countries. Most importantly, it depends on: a. Russia and its energy policy priorities b. Stability in the Middle East. - Policies of consumer countries, including the EU in particular. - Policies of world powers present in the region (USA).

Dynamical Scenarios for Chromosome Bi-orientation

Chromosome bi-orientation at the metaphase spindle is essential for precise segregation of the genetic material. The process is error-prone, and error-correction mechanisms exist to switch misaligned chromosomes to the correct, bi-oriented configuration. Here, we analyze several possible dynamical scenarios to explore how cells might achieve correct bi-orientation in an efficient and robust manner. We first illustrate that tension-mediated feedback between the sister kinetochores can give rise to a bistable switch, which allows robust distinction between a loose attachment with low tension and a strong attachment with high tension. However, this mechanism has difficulties in explaining how bi-orientation is initiated starting from unattached kinetochores. We propose four possible mechanisms to overcome this problem (exploiting molecular noise; allowing an efficient attachment of kinetochores already in the absence of tension; a trial-and-error oscillation; and a stochastic bistable switch), and assess their impact on the bi-orientation process. Based on our results and supported by experimental data, we put forward a trial-and-error oscillation and a stochastic bistable switch as two elegant mechanisms with the potential to promote bi-orientation both efficiently and robustly.