Extracellular Matrix Assembly in Diatoms (Bacillariophyceae)1 : III. Organization of Fucoglucuronogalactans within the Adhesive Stalks of Achnanthes longipes

Achnanthes longipes is a marine, biofouling diatom that adheres to surfaces via adhesive polymers extruded during motility or organized into structures called stalks that contain three distinct regions: the pad, shaft, and collar. Four monoclonal antibodies (AL.C1–AL.C4) and antibodies from two uncloned hybridomas (AL.E1 and AL.E2) were raised against the extracellular adhesives of A. longipes. Antibodies were screened against a hot-water-insoluble/hot-bicarbonate-soluble-fraction. The hot-water-insoluble/hot-bicarbonate-soluble fraction was fractionated to yield polymers in three size ranges: F1, ≥ 20,000,000 Mr; F2, ≅100,000 Mr; and F3, <10,000 Mr relative to dextran standards. The ≅100,000-Mr fraction consisted of highly sulfated (approximately 11%) fucoglucuronogalactans (FGGs) and low-sulfate (approximately 2%) FGGs, whereas F1 was composed of O-linked FGG (F2)-polypeptide (F3) complexes. AL.C1, AL.C2, AL.C4, AL.E1, and AL.E2 recognized carbohydrate complementary regions on FGGs, with antigenicity dependent on fucosyl-containing side chains. AL.C3 was unique in that it had a lower affinity for FGGs and did not label any portion of the shaft. Enzyme-linked immunosorbent assay and immunocytochemistry indicated that low-sulfate FGGs are expelled from pores surrounding the raphe terminus, creating the cylindrical outer layers of the shaft, and that highly sulfated FGGs are extruded from the raphe, forming the central core. Antibody-labeling patterns and other evidence indicated that the shaft central-core region is related to material exuded from the raphe during cell motility.

North Caucasus: the Russian Gordian knot. The key problems and conflicts in the region and the effect thereof on the future of Russia; Putin after re-election: The Kremlin's policy in Vladimir Putin's second term. OSW Study 16/2004

North Caucasus: North Caucasus is the most instable part of the Russian Federation: since the early 90's, there has been going on the military conflict in Chechnya, which is gradually spilling over into the other republics of the region, terrorism seems to have occupied its regular position in the political life of Caucasus, organized crime is flourishing, the tension persists there and military incidents and attacks are breaking out every now and again. During the recent year, the destabilization of the region, which affects many fields of Russian political and social life, has grown to an alarming size. Putin after re-election: Vladimir Putin's first term as President was a period of submitting political, regional and economic lobbies to the Kremlin. The actions Putin has taken since being re-elected are aimed at consolidating the Kremlin's control over the political, economic and social spheres. Further liquidation of political and informational pluralism, an increase of the ruling group's control over state and private property, and an intensification of state propaganda aimed at generating social support for the Kremlin's initiatives have all proceeded apace. These processes reinforce authoritarian tendencies and strengthen the emerging monocentric political system, with the President's strong domination over political, economic and social life.