Racial difference in Acylation Stimulating Protein (ASP) correlates to triglyceride in non-obese and obese African American and Caucasian women

© 2009 Scantlebury-Manning et al; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution Licens

Exploring the symbiotic pangenome of the nitrogen-fixing bacterium Sinorhizobium meliloti

<p>Abstract</p> <p>Background</p> <p><it>Sinorhizobium meliloti </it>is a model system for the studies of symbiotic nitrogen fixation. An extensive polymorphism at the genetic and phenotypic level is present in natural populations of this species, especially in relation with symbiotic promotion of plant growth. AK83 and BL225C are two nodule-isolated strains with diverse symbiotic phenotypes; BL225C is more efficient in promoting growth of the <it>Medicago sativa </it>plants than strain AK83. In order to investigate the genetic determinants of the phenotypic diversification of <it>S. meliloti </it>strains AK83 and BL225C, we sequenced the complete genomes for these two strains.</p> <p>Results</p> <p>With sizes of 7.14 Mbp and 6.97 Mbp, respectively, the genomes of AK83 and BL225C are larger than the laboratory strain Rm1021. The core genome of Rm1021, AK83, BL225C strains included 5124 orthologous groups, while the accessory genome was composed by 2700 orthologous groups. While Rm1021 and BL225C have only three replicons (Chromosome, pSymA and pSymB), AK83 has also two plasmids, 260 and 70 Kbp long. We found 65 interesting orthologous groups of genes that were present only in the accessory genome, consequently responsible for phenotypic diversity and putatively involved in plant-bacterium interaction. Notably, the symbiosis inefficient AK83 lacked several genes required for microaerophilic growth inside nodules, while several genes for accessory functions related to competition, plant invasion and bacteroid tropism were identified only in AK83 and BL225C strains. Presence and extent of polymorphism in regulons of transcription factors involved in symbiotic interaction were also analyzed. Our results indicate that regulons are flexible, with a large number of accessory genes, suggesting that regulons polymorphism could also be a key determinant in the variability of symbiotic performances among the analyzed strains.</p> <p>Conclusions</p> <p>In conclusions, the extended comparative genomics approach revealed a variable subset of genes and regulons that may contribute to the symbiotic diversity.</p

Oral contraceptive pill use and the susceptibility to markers of exercise-induced muscle damage

© 2017, The Author(s). Purpose: Firstly, to establish whether oral contraceptive pill (OCP) users are more susceptible to muscle damage compared to non-users, and secondly, to establish whether differences can be attributed to differences in patella tendon properties. Methods: Nine female OCP users and 9 female non-users participated in the investigation. Combining dynamometry, electromyography and ultrasonography, patella tendon properties and vastus lateralis architectural properties were measured pre and during the first of 6 sets of 12 maximal voluntary eccentric knee extensions. Serum oestrogen levels were measured on the 7th day of the pill cycle and the 14th day of menstrual cycle in OCP users and non-users, respectively. Maximal voluntary isometric knee extension torque loss, creatine kinase and muscle soreness were measured 48 h pre-damage, post-damage, and 48, 96 and 168 h post-damage. Results: Oestrogen levels were significantly lower in OCP users compared to non-users (209 ± 115 and 433 ± 147 pg/ml, respectively, p = 0.004). Proposed determinants of muscle damage, patella tendon stiffness and maximal eccentric torque did not differ between OCP users and non-users. The change in creatine kinase from pre to peak was significantly higher in OCP users compared to non-users (962 ± 968 and 386 ± 474 Ul, respectively, p = 0.016). There were no other differences in markers of muscle damage. Conclusion: Although our findings suggest that, when compared to non-users, the OCP may augment the creatine kinase response following eccentric exercise, it does not increase the susceptibility to any other markers of muscle damage

DEVELOPMENT IN THE DIII-D TOKAMAK OF HYBRID OPERATION SCENARIOS FOR BURNING PLASMA EXPERIMENTS

OAK-B135 The basic parameters of proposed burning plasma experiments such as ITER and FIRE have been chosen based on analysis of multi-machine databases of confinement, stability, and divertor operation. given these specifications, it is of interest to run discharges in present-day machines such as DIII-D to verify the design basis and evaluate the margin available to achieve the mission goals. it is especially important to operate discharges which are stationary with respect to the current relaxation time scale ({tau}{sub R}) since it is well-known that higher performance can be achieved transiently. Attention has been focused on validating the baseline scenario for diverted machines--ELMing H-mode discharges with q{sub 95} = 3 with sawteeth. However, there is also interest in the ITER program to assess the feasibility of operating the tokamak in a mode to maximize the neutron fluence for the purpose of testing the design of various components critical to the nuclear fuel cycle and energy conversion systems in a fusion power plant. It was originally envisioned that these discharges would be intermediate between an inductive burn (baseline) scenario and a fully noninductive (steady state) scenario; therefore, this type of discharge has become known as a hybrid scenario. In the course of investigating these hybrid scenarios in DIII-D, two key results have been obtained. First, stationary discharges with q{sub 95} &gt; 4 have been obtained which project to Q{sub fus} {approx} 10 in ITER. The projected duration of these discharges in ITER when using the full inductive flux capability is &gt; 4000 s. (The significant engineering issues of site heat capacity, activation, and tritium consumption are beyond the scope of this work). Second, utilizing the same plasma initiation techniques as developed for the hybrid scenario, discharges at q{sub 95} = 3.2 project to near ignition in ITER, even with reduced parameters. This indicates the ITER design has significant performance margin and possesses the physics capability to carry out an extensive nuclear testing program. These same q{sub 95} = 3.2 discharges project to Q{sub fus} &gt; 5 in FIRE, even with pessimistic confinement scalings

(Hg,Sb)Ba(2)Ca(2)Cu(3)O(8+delta) thick films on YSZ substrates

Superconducting thick films of (Hg, Sb)Ba2Ca2Cu3O8+δ have been fabricated on polycrystalline yttria-stabilized-zirconia substrates utilizing an Hg-free precursor film reacted with Hg vapour, released from a solid Hg source, in a sealed quartz tube. The resulting films have been studied by x-ray diffraction, scanning electron microscopy, ac susceptibility and resistance measurement techniques. A high quality Hg(Sb)-1223 superconducting thick film on YSZ can be fabricated by using a pre-melted Hg-free precursor film. The zero resistance superconducting transition temperature in the post-growth oxygenated thick film is in excess of 130 K and the transport critical current density for the film is 510 A cm-2 at 77 K

Active and passive spectroscopic imaging in the DIII-D tokamak

Wide-angle, 2D imaging of Doppler-shifted, Balmer alpha (D α) emission from high energy injected neutrals, charge exchange recombination (CER) emission from neutral beam interaction with thermal ions and fully stripped impurity ions and visible bremsstrahlung (VB) from the core of DIII-D plasmas has been carried out. Narrowband interference filters were used to isolate the specific wavelength ranges of visible radiation for detection by a tangentially viewing, fast-framing camera. Measurements of the Dα emission from fast neutrals injected into the plasma from the low field side reveal the vertical distribution of the beam, its divergence and the variation in its radial penetration with density. Modeling of this emission using both a full Monte Carlo collisional radiative code as well as a simple beam attenuation code coupled to Atomic Data and Analysis Structure emissivity lookup tables yields qualitative agreement, however the absolute magnitudes of the emissivities in the predicted distribution are larger than those measured. Active measurements of carbon CER brightness are in agreement with those made independently along the beam midplane using DIII-D's multichordal, CER spectrometer system, confirming the potential of this technique for obtaining 2D profiles of impurity density. Passive imaging of VB, which can be inverted to obtain local emissivity profiles, is compared with measurements from both a calibrated filter/photomultiplier array and the standard multichordal CER spectrometer system. © 2010 IOP Publishing Ltd

Validation of on- and off-axis neutral beam current drive against experiment in DIII-Da

Neutral beam current drive (NBCD) experiments in DIII-D using vertically shifted plasmas to move the current drive away from the axis have clearly demonstrated robust off-axis NBCD. Time-dependent measurements of magnetic field pitch angles by the motional Stark effect diagnostic are used to obtain the evolution of the poloidal magnetic flux, which indicates a broad off-axis NBCD profile with a peak at about half the plasma minor radius. In most cases, the measured off-axis NBCD profile is consistent with calculations using an orbit-following Monte Carlo code for the beam ion slowing down including finite-orbit effects provided there is no large-scale magnetohydrodynamic activity such as Alfv́n eigenmodes modes or sawteeth. An alternative analysis method shows good agreement between the measured pitch angles and those from simulations using transport-equilibrium codes. Two-dimensional image of Doppler-shifted fast ion Dα light emitted by neutralized energetic ions shows clear evidence for a hollow profile of beam ion density, consistent with classical beam ion slowing down. The magnitude of off-axis NBCD is sensitive to the alignment of the beam injection relative to the helical pitch of the magnetic field lines. If the signs of toroidal magnetic field and plasma current yield the proper helicity, both measurement and calculation indicate that the efficiency is as good as on-axis NBCD because the increased fraction of trapped electrons reduces the electron shielding of the injected ion current, in contrast with electron current drive schemes where the trapping of electrons degrades the efficiency. The measured off-axis NBCD increases approximately linearly with the injection power, although a modest amount of fast ion diffusion is needed to explain an observed difference in the NBCD profile between the measurement and the calculation at high injection power. © 2009 American Institute of Physics