256 research outputs found

    Identification of target genes for a MYB-type anthocyanin regulator in Gerbera hybrida

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    Genetic modification of the flavonoid pathway has been used to produce novel colours and colour patterns in ornamental plants as well as to modify the nutritional and pharmaceutical properties of food crops. It has been suggested that co-ordinate control of multiple steps of the pathway with the help of regulatory genes would lead to a more predictable control of metabolic flux. Regulation of anthocyanin biosynthesis has been studied in a common ornamental plant, Gerbera hybrida (Asteraceae). An R2R3-type MYB factor, GMYB10, shares high sequence similarity and is phylogenetically grouped together with previously characterized regulators of anthocyanin pigmentation. Ectopic expression of GMYB10 leads to strongly enhanced accumulation of anthocyanin pigments as well as to an altered pigmentation pattern in transgenic gerbera plants. Anthocyanin analysis indicates that GMYB10 specifically induces cyanidin biosynthesis in undifferentiated callus and in vegetative tissues. Furthermore, in floral tissues enhanced pelargonidin production is detected. Microarray analysis using the gerbera 9K cDNA array revealed a highly predicted set of putative target genes for GMYB10 including new gene family members of both early and late biosynthetic genes of the flavonoid pathway. However, completely new candidate targets, such as a serine carboxypeptidase-like gene as well, as two new MYB domain factors, GMYB11 and GMYB12, whose exact function in phenylpropanoid biosynthesis is not clear yet, were also identified

    Mass measurements in the vicinity of the doubly-magic waiting point 56Ni

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    Masses of 56,57Fe, 53Co^m, 53,56Co, 55,56,57Ni, 57,58Cu, and 59,60Zn have been determined with the JYFLTRAP Penning trap mass spectrometer at IGISOL with a precision of dm/m \le 3 x 10^{-8}. The QEC values for 53Co, 55Ni, 56Ni, 57Cu, 58Cu, and 59Zn have been measured directly with a typical precision of better than 0.7 keV and Coulomb displacement energies have been determined. The Q values for proton captures on 55Co, 56Ni, 58Cu, and 59Cu have been measured directly. The precision of the proton-capture Q value for 56Ni(p,gamma)57Cu, Q(p,gamma) = 689.69(51) keV, crucial for astrophysical rp-process calculations, has been improved by a factor of 37. The excitation energy of the proton emitting spin-gap isomer 53Co^m has been measured precisely, Ex = 3174.3(10) keV, and a Coulomb energy difference of 133.9(10) keV for the 19/2- state has been obtained. Except for 53Co, the mass values have been adjusted within a network of 17 frequency ratio measurements between 13 nuclides which allowed also a determination of the reference masses 55Co, 58Ni, and 59Cu.Comment: 14 pages, 13 figures, submitted to Phys. Rev.

    Electron-capture branch of 100Tc and tests of nuclear wave functions for double-beta decays

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    We present a measurement of the electron-capture branch of 100^{100}Tc. Our value, B(EC)=(2.6Ā±0.4)Ɨ10āˆ’5B(\text{EC}) = (2.6 \pm 0.4) \times 10^{-5}, implies that the 100^{100}Mo neutrino absorption cross section to the ground state of 100^{100}Tc is roughly one third larger than previously thought. Compared to previous measurements, our value of B(EC)B(\text{EC}) prevents a smaller disagreement with QRPA calculations relevant to double-Ī²\beta decay matrix elements

    Total Absorption Spectroscopy Study of 92^{92}Rb Decay: A Major Contributor to Reactor Antineutrino Spectrum Shape

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    The antineutrino spectra measured in recent experiments at reactors are inconsistent with calculations based on the conversion of integral beta spectra recorded at the ILL reactor. 92^{92}Rb makes the dominant contribution to the reactor spectrum in the 5-8 MeV range but its decay properties are in question. We have studied 92^{92}Rb decay with total absorption spectroscopy. Previously unobserved beta feeding was seen in the 4.5-5.5 region and the GS to GS feeding was found to be 87.5(25)%. The impact on the reactor antineutrino spectra calculated with the summation method is shown and discussed.Comment: 6 pages, 3 figure

    Benign afebrile cluster convulsions with gastroenteritis: an observational study

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    BACKROUND: The occurrence of afebrile seizures in association with viral gastroenteritis, without dehydration or electrolyte imbalance, is virtually unknown outside Asia. They are reported to have a benign prognosis and not to require specific investigations or therapy. METHODS: We report the occurrence of such afebrile convulsions in association with viral gastroenteritis without dehydration or electrolyte imbalance, over a 3-year period, in a cohort of 14 British children. RESULTS: The children (5 males and 9 females, 10 Caucasians and 4 Asians) were aged 9 to 60 months (median 14.5 months). All 14 had a normal neurological examination and normal serum biochemistry. Twelve children had generalised seizures and 2 had, in addition, absence seizures. The number of seizures per child ranged from 1 to 8. Most convulsions were short with 85.7% of children having the longest seizure not longer than 4 minutes. The longest duration for a seizure was 10 minutes and occurred in 2 children. Convulsions did not recur after the first day in 10 children, 3 children had recurrences the second day and one child on the fourth day. No convulsions recurred after 4 days. Cerebrospinal fluid studies, computed tomography and electroencephalogram (EEG) were performed on two children who had prolonged seizures and the results were normal. No pathogenic bacteria were grown in any of the stools. Enzyme immunoassay detection of Rotavirus in the stools was positive in 7 of the 10 children where it was tested. All 14 children recovered spontaneously within a few days. On long-term follow of up to 31 months (median 16 months), none had further convulsions and all had normal development milestones. CONCLUSIONS: Afebrile seizures in association with viral gastroenteritis do also occur outside Asia. Recognition of this entity should lead to reassurance of the parents. As in previously published series, investigations such as lumbar puncture, neuroimaging and EEG are usually normal and may not be necessary in most cases. Likewise, published data indicate that long-term anticonvulsant therapy is not usually warranted and the prognosis seems to be reassuring
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