133 research outputs found

    The potential of biological soil disinfestation to manage Fusarium foot and root rot in Asparagus

    Get PDF
    In a field experiment on an abandoned asparagus field we studied the effect of Biological Soil Disinfestation (BSD) on survival of buried inoculum samples of three test pathogens (Fusarium redolens f.sp. asparagi (FRA), Rhizoctonia tuliparum (RT) and Verticillium dahliae (VD)) and on the Fusarium infestation level. The BSD treatments involved incorporation of grass into moist soil and covering the soil with airtight plastic. The amount of grass incorporated was varied (42, 62 or 102 tons of grass/ha) as well as the depth of incorporation (40 or 80 cm). It was found that BSD greatly reduced all three pathogens in buried soil samples and that incorporation of 62 or 102 tons of grass per ha to 80 cm soil depth resulted in a significant decrease in soil infestation in the upper 40 cm; in the deeper layer the decrease was lower. Asparagus plants grown from seed in the field for one year showed a strong decrease in Fusarium root rot severity with all BSD treatments. The results clearly show the potential of BSD to decrease soil infestation levels of Fusarium pathogens and to contribute to an enhanced life span of replanted asparagus crop

    Bestrijding Bamboemijt : Een onderzoek naar de chemische en biologische bestrijdingsmogelijkheden van de bamboemijt

    Get PDF
    De bamboemijten Stigmaeopsis celarius en Stigmaeopsis nanjingensis zorgden, bij de start van dit project, sinds ongeveer 5 jaar in Nederland voor steeds grotere problemen in de bamboeteelt. De schade veroorzaakt door deze bamboemijten neemt dusdanige vormen aan dat kwekers zich zorgen maken over het imago van de bamboeplant als een ‘gezonde’, probleemloze tuinplant. Deze mijtensoorten maken zeer dichte spinsels aan de onderkant van de bladeren. Bij een aantasting neemt de sierwaarde van de planten af. Bij een ernstige aantasting worden de planten onverkoopbaar

    High use of SABAs is associated with higher exacerbation rate in Dutch patients with asthma

    Get PDF
    Funding This study is funded by General Practitioners Research Institute and AstraZeneca Netherlands. The REALISE survey was funded by Mundipharma International Limited (Cambridge, UK). Acknowledgements We would like to thank the core study team, Thys van der Molen, Monica Fletcher, and David Price, the initial researchers of the REALISE study, for their advice on this study. We would like to thank Mundipharma Pharmaceuticals the Netherlands, for providing the data for this study.Peer reviewedPublisher PD

    Testing factorization in B -> D(*)X decays

    Get PDF
    In QCD the amplitude for B0 -> D(*)+pi- factorizes in the large Nc limit or in the large energy limit Q >> Lambda_QCD where Q = {m_b, m_c, m_b-m_c}. Data also suggests factorization in exclusive processes B-> D* pi+ pi- pi- pi0 and B-> D* omega pi-, however by themselves neither large Nc nor large Q can account for this. Noting that the condition for large energy release in B0-> D+ pi- is enforced by the SV limit, m_b, m_c >> m_b-m_c >> Lambda, we propose that the combined large Nc and SV limits justify factorization in B -> D(*) X. This combined limit is tested with the inclusive decay spectrum measured by CLEO. We also give exact large Nc relations among isospin amplitudes for B -> D(*)X and B -> D(*) D-bar(*)X, which can be used to test factorization through exclusive or inclusive measurements. Predictions for the modes B-> D(*) pi pi, B-> D(*)K K-bar and B-> D(*) D-bar(*) K are discussed using available data.Comment: 15 pages, 3 included .eps figures, minor change

    Supersymmetric contributions to B -> D K and the determination of angle \gamma

    Full text link
    We analyze supersymmetric contributions to B^- -> D^0 K^- and B^- ->\bar{D}^0 K^- processes. We investigate the possibility that supersymmetric CP violating phases can affect our determination for the angle \gamma in the unitary triangle of Cabibbo-Kobayashi-Maskaw mixing matrix. We calculate the gluino and chargino contributions to b--> u(\bar{c}s) and b-->c(\bar{u}s) transitions in a model independent way by using the mass insertion approximation method. We also revise the D^0 - \bar{D}^0 mixing constraints on the mass insertions between the first and second generations of the up sector. We emphasize that in case of negligible D^0 -\bar{D}^0 mixing, one should consider simultaneous contributions from more than one mass insertion in order to be able to obtain the CP asymmetries of these processes within their 1\sigma experimental range. However, with a large D^0-\bar{D}^0 mixing, one finds a significant deviation between the two asymmetries and it becomes natural to have them of order the central values of their experimental measurements.Comment: 20 page

    The BcB_c Meson Lifetime

    Get PDF
    We investigate the total inclusive decay rate of the (ground state) BcB_c meson within the framework of an operator product expansion in inverse powers of the heavy quark masses and subsequent matching onto nonrelativistic QCD. The expansion is organized as a series in the strong coupling and in powers of the heavy quark velocities in the BcB_c, reflecting the nonrelativistic nature of a heavy-heavy bound state. In this aspect the character of the expansion differs from the more familiar case of heavy-light mesons. The framework incorporates systematically corrections to the leading bb- and cc-quark decays due to binding effects, as well as contributions from weak annihilation and Pauli interference. Based on this approach we find for the BcB_c meson lifetime τBc=(0.40.7)\tau_{B_c}=(0.4 - 0.7)\,ps, the dominant mechanism being the decay of the charm constituent.Comment: 18 pages, revtex, 2 figures as uudecoded fil

    Protein dynamics influence the enzymatic activity of phospholipase a/acyltransferases 3 and 4

    Get PDF
    Phospholipase A/acyltransferase 3 (PLAAT3) and PLAAT4 are enzymes involved in the synthesis of bioactive lipids. Despite sequential and structural similarities, the two enzymes differ in activity and specificity. The relation between the activity and dynamics of the N-terminal domains of PLAAT3 and PLAAT4 was studied. PLAAT3 has a much higher melting temperature and exhibits less nanosecond and millisecond dynamics in the active site, in particular in loop L2(B6), as shown by NMR spectroscopy and molecular dynamics calculations. Swapping the L2(B6) loops between the two PLAAT enzymes results in strongly increased phospholipase activity in PLAAT3 but no reduction in PLAAT4 activity, indicating that this loop contributes to the low activity of PLAAT3. The results show that, despite structural similarity, protein dynamics differ substantially between the PLAAT variants, which can help to explain the activity and specificity differences.Macromolecular BiochemistryMolecular Physiolog
    corecore