999 research outputs found

    Hypericum perforatum plant cells reduce Agrobacterium viability during co-cultivation

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    Plant recalcitrance is the major barrier in developing Agrobacterium-mediated transformation protocols for several important plant species. Despite the substantial knowledge of T-DNA transfer process, very little is known about the factors leading to the plant recalcitrance. Here, we analyzed the basis of Hypericum perforatum L. (HP) recalcitrance to Agrobacterium-mediated transformation using cell suspension culture. When challenged with Agrobacterium, HP cells swiftly produced an intense oxidative burst, a typical reaction of plant defense. Agrobacterium viability started to decline and reached 99% mortality within 12 h, while the plant cells did not suffer apoptotic process. This is the first evidence showing that the reduction of Agrobacterium viability during co-cultivation with recalcitrant plant cells can affect transformation

    Double dermal sinuses: a case study

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    <p>Abstract</p> <p>Introduction</p> <p>Dermal sinus tracts are rare congenital lesions located in the midline characterized by a cutaneous pit or dimple. They occur all along the midline neuroaxis, from the nasion and occipital area down to the lumbar and sacral regions, most frequently in the lumbar and lumbosacral region.</p> <p>Case presentation</p> <p>Here we report a 5-year-old girl who presented with occasional headache. There were two dimples, one on the dorsal aspect of her head and another on her neck.</p> <p>Conclusion</p> <p>Dermal sinuses are almost always singular and the co-existence of double dermal sinuses has not been reported previously.</p

    A new approach to bad news effects on volatilit y: the multiple-sign-volume sensitive regime EGARCH model (MSV-EGARCH)

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    In this paper, using daily data for six major international stock market indexes and a modified EGARCH specification, the links between stock market returns, volatility and trading volume are investigated in a new nonlinear conditional variance framework with multiple regimes and volume eff ects. Volatility forecast comparisons, using the Harvey-Newbold test for multiple forecasts encompassing, seem to demonstrate that the MSV- EGARCH complex threshold structure is able to correctly fit GARCH- type dynamics of the series under study and dominates competing standard asymmetric models in several of the considered stock indexes.info:eu-repo/semantics/publishedVersio
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