49 research outputs found

    Extreme Differentiation along Multiple Liquid Lines of Descent in Strongly Peralkaline Magma Series at Pantelleria (Italy)

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    The liquid line of descent from trachyte to pantellerite is controlled primarily by fractional crystallization of alkali feldspar, with whole rock compositions following a fractionation path along the ‘thermal valley’ in the peralkaline haplogranite system Qz-Ab-Or-Ac-Ns and terminating at a minimum on the feldspar-quartz cotectic. Although whole-rock compositions for different pantelleritic suites follow nearly identical paths in a Qz-Ab-Or projection that terminate near the experimental minimum (Qz40.5Or34.5Ab25 at 100 MPa, projected from Ac-Ns), matrix glass from samples with near-minimum compositions record extreme differentiation and form a ‘cotectic delta’ beyond the terminus of the ‘thermal valley’. Although each glass trend shows a continuing increase in Zr to \u3e3000 μg/g, the most evolved compositions in each suite differ in peralkalinity (mol [Na+K] / Al) and in the proportions of FeOT, Qz, Ab, Or, and other components, which are related to subtle variations in the mafic phases controlled mainly by differences in oxygen fugacity (fO2)and pressure (P). To determine the controls over mafic mineral crystallization in pantelleritic magmas and the various paths these suites take beyond the apparent (whole-rock) minimum, amphibole-phyric suites from the ∼159 ka Cala dell’Altura and Cala Gadir volcanic centres and the ∼8–10 ka Cuddia Mida volcanic centre on Pantelleria have been analyzed and compared with each other and with the well-characterized and amphibole-free, compositionally zoned Green Tuff, the ∼46 ka caldera-forming ignimbrite of the Cinque Denti caldera. Differences between the extended fractionation trends may be ultimately attributed to variations in oxygen fugacity, depth of emplacement, and water saturation. Shallower (lower pressure) magma reservoirs such as the one for the Green Tuff are water saturated and undergo degassing, which leads to an increase in relative oxygen fugacity. Deeper (higher pressure) magma reservoirs remain water-undersaturated and retain water in the melt, which both maintains lower relative oxygen fugacities and enables the crystallization of amphibole. Amphibole formation appears to require melt water contents \u3e4 wt%, low oxygen fugacity

    Tuberous sclerosis complex neuropathology requires glutamate-cysteine ligase

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    Introduction: Tuberous sclerosis complex (TSC) is a genetic disease resulting from mutation in TSC1 or TSC2 and subsequent hyperactivation of mammalian Target of Rapamycin (mTOR). Common TSC features include brain lesions, such as cortical tubers and subependymal giant cell astrocytomas (SEGAs). However, the current treatment with mTOR inhibitors has critical limitations. We aimed to identify new targets for TSC pharmacotherapy. Results: The results of our shRNA screen point to glutamate-cysteine ligase catalytic subunit (GCLC), a key enzyme in glutathione synthesis, as a contributor to TSC-related phenotype. GCLC inhibition increased cellular stress and reduced mTOR hyperactivity in TSC2-depleted neurons and SEGA-derived cells. Moreover, patients’ brain tubers showed elevated GCLC and stress markers expression. Finally, GCLC inhibition led to growth arrest and death of SEGA-derived cells. Conclusions: We describe GCLC as a part of redox adaptation in TSC, needed for overgrowth and survival of mutant cells, and provide a potential novel target for SEGA treatment. Electronic supplementary material The online version of this article (doi:10.1186/s40478-015-0225-z) contains supplementary material, which is available to authorized users

    Igf1r Signaling Is Indispensable for Preimplantation Development and Is Activated via a Novel Function of E-cadherin

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    Insulin-like growth factor I receptor (Igf1r) signaling controls proliferation, differentiation, growth, and cell survival in many tissues; and its deregulated activity is involved in tumorigenesis. Although important during fetal growth and postnatal life, a function for the Igf pathway during preimplantation development has not been described. We show that abrogating Igf1r signaling with specific inhibitors blocks trophectoderm formation and compromises embryo survival during murine blastocyst formation. In normal embryos total Igf1r is present throughout the membrane, whereas the activated form is found exclusively at cell contact sites, colocalizing with E-cadherin. Using genetic domain switching, we show a requirement for E-cadherin to maintain proper activation of Igf1r. Embryos expressing exclusively a cadherin chimera with N-cadherin extracellular and E-cadherin intracellular domains (NcEc) fail to form a trophectoderm and cells die by apoptosis. In contrast, homozygous mutant embryos expressing a reverse-structured chimera (EcNc) show trophectoderm survival and blastocoel cavitation, indicating a crucial and non-substitutable role of the E-cadherin ectodomain for these processes. Strikingly, blastocyst formation can be rescued in homozygous NcEc embryos by restoring Igf1r signaling, which enhances cell survival. Hence, perturbation of E-cadherin extracellular integrity, independent of its cell-adhesion function, blocked Igf1r signaling and induced cell death in the trophectoderm. Our results reveal an important and yet undiscovered function of Igf1r during preimplantation development mediated by a unique physical interaction between Igf1r and E-cadherin indispensable for proper receptor activation and anti-apoptotic signaling. We provide novel insights into how ligand-dependent Igf1r activity is additionally gated to sense developmental potential in utero and into a bifunctional role of adhesion molecules in contact formation and signaling

    Association between funding source, methodological quality and research outcomes in randomized controlled trials of synbiotics, probiotics and prebiotics added to infant formula: A Systematic Review

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    The impact of funding structure on EU banking sector stability

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    In our paper, we analyse the impact of funding structure on banking sector stability in EU countries. Our findings show that after the global financial crisis (GFC) there are four main funding models in the EU banking sectors. We document that funding structure is an important factor influencing the banking sector stability. We report that there are also some other banking business model characteristics as well as macroeconomic indicators which have impact on banking sector risk

    Impact of climate change on water demand of late potato

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    Praca zawiera analizę wpływu prognozowanej zmiany klimatu na zapotrzebowanie na wodę ziemniaka późnego w latach 2021–2050 oraz 2071–2100. Dane meteorologiczne zostały pozyskane z modelu regionalnego RM5.1, z warunkami brzegowymi z modelu globalnego ARPEGE dla scenariusza emisji SRES: A1B. Okresem referencyjnym były lata 1971–2000. Miarą zapotrzebowania wody przez daną roślinę uprawną dla wydania określonego plonu jest ewapotranspiracja potencjalna tej rośliny. Obliczono ją przy użyciu metody Penmana-Monteitha i współczynników roślinnych. Wpływ zmian klimatu na ewapotranspirację potencjalną ziemniaka późnego na obszarze Polski oceniano na pięciu stacjach meteorologicznych, reprezentatywnych dla regionów agroklimatycznych: Olsztyn, Bydgoszcz, Warszawa, Wrocław, Kraków. W wieloleciach 2021–2050 i 2071–2100 zwiększy się zapotrzebowanie na wodę w uprawie ziemniaka późnego. W wieloleciu 2021-2050 są spodziewane kilkuprocentowe wzrosty (do 7%), natomiast w latach 2071-2100 prognozowany wzrost będzie jeszcze większy (do 18%). Największy wzrost zapotrzebowania nastąpi w regionie południowo-zachodnim i środkowo-wschodnim, a najmniejszy w południu-wschodnim. Przewidywane zmiany klimatyczne i związany z nimi wzrost zapotrzebowania na wodę przez rośliny, powinny spowodować zwiększenie powierzchni nawadnianej i wzrost zapotrzebowania na wodę do nawodnień.The paper presents the analysis of the impact of predicted climate change on water demand of late potato in 2021–2050 and 2071–2100. Meteorological data were simulated with the regional model RM5.1 with boundary conditions from the global model ARPEGE for the scenario SRES: A1B. Reference period was 1971–2000. The measure of crop water demand is potential evapotranspiration. It was calculated using the Penman-Monteith method and crop factors. The impact of climate change on potential evapotranspiration of late potato was evaluated in Poland at the five meteorological stations representative for agroclimatic regions: Olsztyn, Bydgoszcz, Warszawa, Wrocław, Kraków. Water demand of late potato will increase of up to 7% in 2021-2050 and of up to 18% in 2071-2100. Increase will be the biggest in the south-west and central- east regions and the smallest in south-east region. Predicted climate change and increased crop water demand should result in increase of irrigated area and irrigation water requirements

    Application of the optical flow and critical success index methods to verification of precipitation in climate simulations over Poland

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