42 research outputs found

    Characterisation of two desiccation-stress related cDNAs TrDr1 and TrDr2 in the resurrection moss Tortula ruralis11The nucleotide sequence reported in this paper appears in EMBL, GenBank and DDBJ Nucleotide Sequence Databases under the accession numbers AI304977 (TrDr1) and AI305064 (TrDr2)

    Get PDF
    Two EST-derived cDNAs TrDr1 and TrDr2 from Tortula ruralis were identified with significant similarity to psbI encoding the PSII 10kDa protein and the desiccation stress-related cDNA pcC3-06, respectively. RNA blot hybridisation using both total and polysomal RNA fractions was used to analyse TrDr1 and TrDr2 mRNA abundance in response to a desiccation/rehydration cycle. TrDr1 and TrDr2 steady-state transcript levels increased in response to desiccation and preferentially accumulated within the polysomal mRNA fraction. The data suggest that TrDR1 and TrDR2 play a role in vegetative desiccation- tolerance

    The effect of water stress on the germination of Citrullus lanatus seeds

    Get PDF
    The germination of Citrullus lanatus seeds is extremely sensitive to water stress. A decrease of 13,6 % in the total water content is sufficient for the complete inhibition of germination. Exposure of seeds to water stress at a very late stage of germination after normal incubation in water prevents radicle emergence. Prolonged water stress treatment does not induce secondary dormancy in these seeds. Water stress which completely inhibits germination does not appear to affect the conversion of phytochrome intermediates to Pfr or the photoreversibility of phytochrome during light treatments

    Human leucocyte typing in clinical transplantation

    Get PDF
    No Abstract

    Abnormal haemoglobins in Cape Town

    Get PDF
    No Abstract

    Intra-uterine foetal blood transfusion

    Get PDF
    No Abstract

    Expression of a β-1,3-glucanase from a biocontrol fungus in transgenic pearl millet

    Get PDF
    Sclerospora graminicola is an oomycete (heterotrophic Stramenopiles), fungal-like obligate phytopathogen, the causal agent of downy mildew in pearl millet (Pennisetum glaucum [L.] R. Br.), and a major constraint in the production of this cereal crop. In this study a hydrolytic enzyme, β-1,3-glucanase (gluc78), from the biocontrol fungus Trichoderma atroviride, was introduced into the genome of a pearl millet breeding line, 842B, by particle bombardment. Constructs were prepared containing the gluc78 gene, encoding the 78 kDa β-1,3-glucanase protein, downstream of either the constitutive ubiquitin promoter or the wound inducible potato proteinase inhibitor IIK gene promoter (pin2). The positive selectable marker gene, manA, encoding mannose-6-phosphate isomerase (phosphomannose isomerase) under the control of the ubiquitin promoter, was used for co-transformation. Transgenic plants were obtained harbouring the manA selectable marker gene and the antifungal gene gluc78 downstream of either the ubiquitin or pin2 promoter. Full constructs or minimal transgene expression cassettes containing the genes of interest were successfully introduced into the genome of pearl millet. Progeny of stably transformed plants, harbouring the gluc78 transgene which is driven by the pin2 promoter and followed by the rice Act1 intron sequences, was subjected to pathogenicity trials. One transgenic event exhibited a reduction of 58% in the incidence of S. graminicola infection, however other transgenic pearl millet events showed no resistance to this phytopathogen. The event conferring decreased susceptibility to S. graminicola had high levels of the glucanase transcript especially in transgenic plants showing higher levels of downy mildew infection.The European Commission contract number: ERBIC18 CT98 0316. Some results presented in this document are outputs from several research projects of the Plant Sciences Research Programme funded by the UK Department for International Development (DFID) and administered by the Centre for Arid Zone Studies (CAZS) for the benefit of developing countries.http://www.elsevier.com/locate/sajbnf201

    Multiwavelength Observations of Supersonic Plasma Blob Triggered by Reconnection Generated Velocity Pulse in AR10808

    Full text link
    Using multi-wavelength observations of Solar and Heliospheric Observatory (SoHO)/Michelson Doppler Imager (MDI), Transition Region and Coronal Explorer (TRACE) 171 \AA, and Hα\alpha from Culgoora Solar Observatory at Narrabri, Australia, we present a unique observational signature of a propagating supersonic plasma blob before an M6.2 class solar flare in AR10808 on 9th September 2005. The blob was observed between 05:27 UT to 05:32 UT with almost a constant shape for the first 2-3 minutes, and thereafter it quickly vanished in the corona. The observed lower bound speed of the blob is estimated as \sim215 km s1^{-1} in its dynamical phase. The evidence of the blob with almost similar shape and velocity concurrent in Hα\alpha and TRACE 171 \AA\ supports its formation by multi-temperature plasma. The energy release by a recurrent 3-D reconnection process via the separator dome below the magnetic null point, between the emerging flux and pre-existing field lines in the lower solar atmosphere, is found to be the driver of a radial velocity pulse outwards that accelerates this plasma blob in the solar atmosphere. In support of identification of the possible driver of the observed eruption, we solve the two-dimensional ideal magnetohydrodynamic equations numerically to simulate the observed supersonic plasma blob. The numerical modelling closely match the observed velocity, evolution of multi-temperature plasma, and quick vanishing of the blob found in the observations. Under typical coronal conditions, such blobs may also carry an energy flux of 7.0×106\times10^{6} ergs cm2^{-2} s1^{-1} to re-balance the coronal losses above active regions.Comment: Solar Physics; 22 Pages; 8 Figure

    Magnetohydrodynamic Oscillations in the Solar Corona and Earth’s Magnetosphere: Towards Consolidated Understanding

    Full text link
    corecore