1,448 research outputs found

    EVALUATION OF THE EFFECTIVENESS OF NATURAL ALTERNATIVE COPPER PRODUCTS AND LOW RATE COPPER FORMULATIONS AGAINST GRAPE DOWNY MILDEW IN ORGANIC VITICULTURE

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    The control of pathogenic fungi, especially downy mildew, represents the main problem in organic viticulture as only few fungicides, above all copper salts, can be used. As the copper causes problems of environmental impact, the Regulation EC n. 473/2002 fixed a ceiling on the use of copper compounds. Two years field trials were carried out in organic vineyeards to test the effectiveness, against Plasmopara viticola (Berk. et Curt.) Berl. et De Toni, of alternative copper products and low rate copper formulations, able to take place or to reduce copper quantities used. Amoung the alternative substances, in the first year of activity we examinated phito-stimulant and cuprics, while in the second year we examinated natural extracts, both vegetables and animals, and natural compound associates to the copper. The achieved results have underlined that, using the low rate copper formulations examinated, the total copper quantities were always less than 6 Kg copper per hectare, in accordance with the provisions of Regulation EC. The alternative products investigated have not guaranteed, instead, an adequate protection with high pressure od downy mildew. The trials confirm that the copper is indispensable for plant protection in organic farming, as it is not possible to replace it. We can only reduce the copper quantities used, at this point of time, but further studies are necessary to find appropriate alternative solutions able to control pathogenic agents in organic farming

    Inverse diffraction for the Atmospheric Imaging Assembly in the Solar Dynamics Observatory

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    The Atmospheric Imaging Assembly in the Solar Dynamics Observatory provides full Sun images every 1 seconds in each of 7 Extreme Ultraviolet passbands. However, for a significant amount of these images, saturation affects their most intense core, preventing scientists from a full exploitation of their physical meaning. In this paper we describe a mathematical and automatic procedure for the recovery of information in the primary saturation region based on a correlation/inversion analysis of the diffraction pattern associated to the telescope observations. Further, we suggest an interpolation-based method for determining the image background that allows the recovery of information also in the region of secondary saturation (blooming)

    Genome scale metabolic modeling reveals the metabolic potential of three Type II methanotrophs of the genus Methylocystis

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    Producción CientíficaGenome Scale Metabolic Models (GSMMs) of the recently sequenced Methylocystis hirsuta and two other methanotrophs from the genus Methylocystis have been reconstructed. These organisms are Type II methanotrophs with the ability of accumulating Polyhydroxyalkanoates under nutrient limiting conditions. For the first time, GSMMs have been reconstructed for Type II methanotrophs. These models, combined with experimental biomass and PHB yields of Methylocystis hirsuta, allowed elucidating the methane oxidation mechanism by the enzyme pMMO (particulate methane monooxygenase) in these organisms. In contrast to Type I methanotrophs, which use the “direct coupling mechanism”, Type II methanotrophs appear to use the so called “redox arm mechanism”. The utilization of the “redox arm mechanism”, which involves the coupling between methane oxidation and complex I of the respiratory chain, was confirmed by inhibition of complex I with catechol. Utilization of the “redox arm” mechanism leads to lower biomass yields on methane compared to Type I methanotrophs. However, the ability of Type II methanotrophs to redirect high metabolic carbon fluxes towards acetoacetyl-CoA under nitrogen limiting conditions makes these organisms promising platforms for metabolic engineering.Marie Curie grant H2020-MSCA-IF-2016 CH4BioVal (GA nº 750126).Junta de Castilla y León (Ref. Project VA281P18)Ministerio de Ciencia e Innovación (Proyect CLU 2017-09, CTM2015-70442-R

    Remembering Luisa Leone (1967-2014)

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    Factors influencing response to ingenol mebutate therapy for actinic keratosis of face and scalp

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    AIM To determine factors independently influencing response to ingenol mebutate therapy and assess efficacy on clinical setting of non-hypertrophic non-hyperkeratotic actinic keratosis (AK). METHODS Consecutive patients affected by non-hypertrophic non-hyperkeratotic AKs of the face or scalp were enrolled to receive ingenol mebutate 0.015% gel on a selected skin area of 25 cm2 for 3 consecutive days. Local skin reactions were calculated at each follow up visit using a validated composite score. Efficacy was evaluated by the comparison of clinical and dermoscopic pictures before the treatment and at day 57, and classified as complete, partial and poor response. RESULTS A number of 130 patients were enrolled, of which 101 (77.7%) were treated on the face, while 29 (22.3%) on the scalp. The great majority of our study population (n = 119, 91.5%) reached at least a 75% clearance of AKs and, in particular, 58 patients (44.6%) achieved a complete response while 61 (46.9%) a partial one. Logistic backward multivariate analysis showed that facial localization, level of local skin reaction (LSR) at day 2, the highest LSR values and level of crusts at day 8 were factors independently associated with the achievement of a complete response. CONCLUSION Ingenol mebutate 0.015% gel, when properly applied, is more effective on the face than on the scalp and efficacy is directly associated to LSR score

    Properties of the Acceleration Regions in Several Loop-structured Solar Flares

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    Using {\em RHESSI} hard X-ray imaging spectroscopy observations, we analyze electron flux maps for a number of extended coronal loop flares. For each event, we fit a collisional model with an extended acceleration region to the observed variation of loop length with electron energy EE, resulting in estimates of the plasma density in, and longitudinal extent of, the acceleration region. These quantities in turn allow inference of the number of particles within the acceleration region and hence the filling factor ff -- the ratio of the emitting volume to the volume that encompasses the emitting region(s). We obtain values of ff that lie mostly between 0.1 and 1.0; the (geometric) mean value is f=0.20×÷3.9f = 0.20 \times \div 3.9, somewhat less than, but nevertheless consistent with, unity. Further, coupling information on the number of particles in the acceleration region with information on the total rate of acceleration of particles above a certain reference energy (obtained from spatially-integrated hard X-ray data) also allows inference of the specific acceleration rate (electron s1^{-1} per ambient electron above the chosen reference energy). We obtain a (geometric) mean value of the specific acceleration rate η(20\eta(20 keV) =(6.0×/÷3.4)×103 = (6.0 \times / \div 3.4) \times 10^{-3} electrons s1^{-1} per ambient electron; this value has implications both for the global electrodynamics associated with replenishment of the acceleration region and for the nature of the particle acceleration process

    A weakly correlated Fermi liquid state with a small Fermi surface in lightly doped Sr3_3Ir2_2O7_7

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    We characterize the electron doping evolution of (Sr1x_{1-x}Lax_x)3_3Ir2_2O7_7 by means of angle-resolved photoemission. Concomitant with the metal insulator transition around x0.05x\approx0.05 we find the emergence of coherent quasiparticle states forming a closed small Fermi surface of volume 3x/23x/2, where xx is the independently measured La concentration. The quasiparticle weight ZZ remains large along the entire Fermi surface, consistent with the moderate renormalization of the low-energy dispersion. This indicates a conventional, weakly correlated Fermi liquid state with a momentum independent residue Z0.5Z\approx0.5 in lightly doped Sr3_3Ir2_2O$_7&.Comment: 5 pages, 4 figure

    Effects of Adult Müller Cells and Their Conditioned Media on the Survival of Stem Cell-Derived Retinal Ganglion Cells

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    Retinal neurons, particularly retinal ganglion cells (RGCs), are susceptible to the degenerative damage caused by different inherited conditions and environmental insults, leading to irreversible vision loss and, ultimately, blindness. Numerous strategies are being tested in different models of degeneration to restore vision and, in recent years, stem cell technologies have offered novel avenues to obtain donor cells for replacement therapies. To date, stem cell–based transplantation in the retina has been attempted as treatment for photoreceptor degeneration, but the same tools could potentially be applied to other retinal cell types, including RGCs. However, RGC-like cells are not an abundant cell type in stem cell–derived cultures and, often, these cells degenerate over time in vitro. To overcome this limitation, we have taken advantage of the neuroprotective properties of Müller glia (one of the main glial cell types in the retina) and we have examined whether Müller glia and the factors they secrete could promote RGC-like cell survival in organoid cultures. Accordingly, stem cell-derived RGC-like cells were co-cultured with adult Müller cells or Müller cell-conditioned media was added to the cultures. Remarkably, RGC-like cell survival was substantially enhanced in both culture conditions, and we also observed a significant increase in their neurite length. Interestingly, Atoh7, a transcription factor required for RGC development, was up-regulated in stem cell-derived organoids exposed to conditioned media, suggesting that Müller cells may also enhance the survival of retinal progenitors and/or postmitotic precursor cells. In conclusion, Müller cells and the factors they release promote organoid-derived RGC-like cell survival, neuritogenesis, and possibly neuronal maturation.This work was supported by National Institutes of Health Grant R01EY026942 to A.L.T., and by the National Institutes of Health T32 Vision Science Training grant 4T32EY015387 to A.M.M. We also benefit from the National Eye Institute Core Facilities grant P30 EY012576. ELKARTEK KK-2019/00086 to E.V., Research groups of the UPV/EHU (GIU 2018/50) to E.V., Movilidad de personal de investigación UPV/EHU to X.P. and Programa de perfeccionamiento de personal Investigador Doctor, Gobierno Vasco (POS_2019_1_0027) to X.P
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