Active control of type-I edge-localized modes with n=1 perturbation fields in the JET tokamak.

Type-I edge-localized modes (ELMs) have been mitigated at the JET tokamak using a static external n=1 perturbation field generated by four error field correction coils located far from the plasma. During the application of the n=1 field the ELM frequency increased by a factor of 4 and the amplitude of the D(alpha) signal decreased. The energy loss per ELM normalized to the total stored energy, DeltaW/W, dropped to values below 2%. Transport analyses shows no or only a moderate (up to 20%) degradation of energy confinement time during the ELM mitigation phase.

Role of myeloperoxidase-mediated modification of human blood lipoproteins in atherosclerosis development.

The mechanism of interaction of hypochlorite and hypobromite formed in myeloperoxidase catalysis with lipids of human blood low-density lipoprotein is described. Both agents react with unsaturated lipids via two mechanisms: molecular (with the formation of mainly chloro- or bromohydrins and lysophospholipids) and free-radical (paralleled by lipid peroxidation). These reactions modify physicochemical properties of low-density lipoproteins and disorder their lipid-transporting function thus initiating early stages of atherosclerosis development.

Generation of noninductive current by electron-Bernstein waves on the COMPASS-D Tokamak.

Electron-Bernstein waves (EBW) were excited in the plasma by mode converted extraordinary (X) waves launched from the high field side of the COMPASS-D tokamak at different toroidal angles. It has been found experimentally that X-mode injection perpendicular to the magnetic field provides maximum heating efficiency. Noninductive currents of up to 100 kA were found to be driven by the EBW mode with countercurrent drive. These results are consistent with ray tracing and quasilinear Fokker-Planck simulations.

JET quasistationary internal-transport-barrier operation with active control of the pressure profile.

Quasistationary operation has been achieved on the Joint European Torus tokamak in internal-transport-barrier (ITB) scenarios, with the discharge time limited only by plant constraints. Full current drive was obtained over all the high performance phase by using lower hybrid current drive. For the first time feedback control on the total pressure and on the electron temperature profile was implemented by using, respectively, the neutral beams and the ion-cyclotron waves. Although impurity accumulation could be a problem in steady state ITBs, these experiments bring some elements to answer to it.

Dimensions of homo- and heteropolymeric sections of DNA synthesized by reverse transcription from globin mRNA matrices.

The lengths of globin messenger RNAs, isolated from rabbit and pigeon reticulocytes, and single-stranded complementary DNAs, synthesized from mRNA in presence of RNA-directed DNA-polymerase and oligo(dt) have been investigated by polyacrylamide gel electrophoresis under denaturing conditions. The cDNA preparations contained a fraction which corresponded in length to the alpha and beta chains of the mRNA used as a matrix. The lengthwise distribution of poly(A) sequences, isolated from globin mRNAs, corresponded to a statistical distribution, with a maximum at 75-80 nucleotides and with a maximum length of approximately 150 nucleotides. The lengthwise distribution of poly(dt) sequences, isolated from cDNA, corresponded to the poly(A) sequence distribution. It was concluded that: 1) cDNA is heterogeneous with respect to the length of poly(dt) sequences located at the 5' end of the molecule; 2) there was no selective use as primer of only that oligo(dt) which was located within the complex formed with the 5' end of the mRNA poly(A) sequence; 3) the heterogeneity of poly(DT) corresponded qualitatively to two models of template-primer interaction: selective use as a true primer of the oligonucleotide located in the complex formed with the 3' end of mRNA, and a statistical distribution of primer along the poly(A) sequence; and 4) the heterogeneity of the homopolymeric section of the cDNA may affect the kinetics of hybridization with mRNA, which possibly explains the previously observed [1] anomalous dependence of the hybridization rate on time.

Transcription of repetitive and unique DNA nucleotide sequences in pigeon erythroid cells with different degrees of specialization.

HnRNA fractions with sedimentation coefficients greater than 45 S isolated from pigeon bone marrow as well as from the immature and mature erythroid cells of periferal blood were hybridised with a large excess of DNA fractionated on the basis of renaturation kinetics. 58-62% of the input RNAs were recovered as RNAase-resistant hybrids. About 1/3 (20%) of bone marrow greater than 45 S RNA found in the hybrids was hybridised with the repetitive and baout 2/3 (40%) with the unique DNA sequences. In addition, a considerably smaller portion of greater than 45 S RNA from the "reticulocytes" (13%) and "erythrocytes" (approximately 6%) was hybridised with the repetitive DNA.

Hybridization of pigeon globin messenger RNA with complementary DNA synthesized in vitro by reverse transcription: influence of the homopolymeric regions.

The kinetics of hybridization of pigeon globin messenger RNA with complementary cDNA synthesized by means of AMV reverse transcriptase is complex. Addition of poly A or poly U in excess to the reaction mixture normalized the kinetics. It is concluded that association of the complementary homopolymeric regions of mRNA and cDNA accelerates the complex formation between heteropolymeric sequences in a fraction of the molecules.