1,016 research outputs found

    George S. Newberry Collection, 1886-1954.

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    Collection is made up of eclectic mix of clippings and documents related to George S. Newberry?s career in banking, investment and insurance

    Sea-level and ocean-currents

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    Promoter Recognition by a Complex of Spx and the C-Terminal Domain of the RNA Polymerase α Subunit

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    Spx, an ArsC (arsenate reductase) family member, is a global transcriptional regulator of the microbial stress response and is highly conserved amongst Gram-positive bacteria. Bacillus subtilis Spx protein exerts positive and negative control of transcription through its interaction with the C-terminal domain of the RNA polymerase (RNAP) alpha subunit (alphaCTD). Spx activates trxA (thioredoxin) and trxB (thioredoxin reductase) in response to thiol stress, and bears an N-terminal C10XXC13 redox disulfide center that is oxidized in active Spx.The structure of mutant Spx(C10S) showed a change in the conformation of helix alpha4. Amino acid substitutions R60E and K62E within and adjacent to helix alpha4 conferred defects in Spx-activated transcription but not Spx-dependent repression. Electrophoretic mobility-shift assays showed alphaCTD interaction with trxB promoter DNA, but addition of Spx generated a supershifted complex that was disrupted in the presence of reductant (DTT). Interaction of alphaCTD/Spx complex with promoter DNA required the cis-acting elements -45AGCA-42 and -34AGCG-31 of the trxB promoter. The Spx(G52R) mutant, defective in alphaCTD binding, did not interact with the alphaCTD-trxB complex. Spx(R60E) not only failed to complex with alphaCTD-trxB, but also disrupted alphaCTD-trxB DNA interaction.The results show that Spx and alphaCTD form a complex that recognizes the promoter DNA of an Spx-controlled gene. A conformational change during oxidation of Spx to the disulfide form likely alters the structure of Spx alpha helix alpha4, which contains residues that function in transcriptional activation and alphaCTD/Spx-promoter interaction. The results suggest that one of these residues, R60 of the alpha4 region of oxidized Spx, functions in alphaCTD/Spx-promoter contact but not in alphaCTD interaction

    Noodles made from high amylose wheat flour attenuate postprandial glycaemia in healthy adults

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    Previous research has not considered the effect of high amylose wheat noodles on postprandial glycaemia. The aim of the study is to investigate the effect of consumption of high amylose noodles on postprandial glycaemia over 2-h periods by monitoring changes in blood glucose concentration and calculating the total area under the blood glucose concentration curve. Twelve healthy young adults were recruited to a repeated measure randomised, single-blinded crossover trial to compare the effect of consuming noodles (180 g) containing 15%, 20% and 45% amylose on postprandial glycaemia. Fasting blood glucose concentrations were taken via finger-prick blood samples. Postprandial blood glucose concentrations were taken at 15, 30, 45, 60, 90 and 120 min. Subjects consuming high amylose noodles made with flour containing 45% amylose had significantly lower blood glucose concentration at 15, 30 and 45 min (5.5 ± 0.11, 6.1 ± 0.11 and 5.6 ± 0.11 mmol/L; p = 0.01) compared to subjects consuming low amylose noodles with 15% amylose (5.8 ± 0.12, 6.6 ± 0.12 and 5.9 ± 0.12 mmol/L). The total area under the blood glucose concentration curve after consumption of high amylose noodles with 45% amylose was 640.4 ± 9.49 mmol/L/min, 3.4% lower than consumption of low amylose noodles with 15% amylose (662.9 ± 9.49 mmol/L/min), p = 0.021. Noodles made from high amylose wheat flour attenuate postprandial glycaemia in healthy young adults, as characterised by the significantly lower blood glucose concentration and a 3.4% reduction in glycaemic response

    VLT Suzaku observations of the Fermi pulsar PSR J1028-5819

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    We used optical images taken with the Very Large Telescope (VLT) in the B and V bands to search for the optical counterpart of PSR J1028-5819 or constrain its optical brightness. At the same time, we used an archival Suzaku observation to confirm the preliminary identification of the pulsar's X-ray counterpart obtained by Swift. Due to the large uncertainty on the pulsar's radio position and the presence of a bright (V = 13.2) early F-type star at < 4", we could not detect its counterpart down to flux limits of B~25.4 and V ~25.3, the deepest obtained so far for PSR J1028-5819. From the Suzaku observations, we found that the X-ray spectrum of the pulsar's candidate counterpart is best-fit by a power-law with spectral index 1.7 +/- 0.2 and an absorption column density NH < 10^21 cm-2, which would support the proposed X-ray identification. Moreover, we found possible evidence for the presence of diffuse emission around the pulsar. If real, and associated with a pulsar wind nebula (PWN), its surface brightness and angular extent would be compatible with the expectations for a ~100 kyr old pulsar at the PSR J1028-5819 distance.Comment: 10 pages, 9 figures, submitted to Astronomy and Astrophysic
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