15,003 research outputs found

    Are algae ready to take off? GHG emission savings of algae-to-kerosene production

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    Aviation alternative fuels are perceived as an effective short-term mean to decarbonise our flights. Sustainable aviation fuels from algae have been recently approved for commercial flights, and here we present an assessment of their greenhouse gas (GHG) savings. Three case studies have been investigated with different plant designs and cultivation strategies. The Carbon Offsetting and Reduction Scheme for International Aviation's Life Cycle Assessment methodology is used as a guideline to assess the GHG saving potential of aviation fuels from algae. The approach here presented allows having a sound comparison with other alternative fuel production pathways. We show that the cultivation strategy based on oil maximisation does not necessarily provide significant advantages in terms of GHG savings. The assessed GHG savings fall in a wide range, being dependent on the inputs and cultivation strategy considered. In the best-case scenario, up to 68% of GHG savings can be achieved, therefore offering a substantial advantage over traditional fuels. When compared with the GHG saving of kerosene from other traditional bio-based feedstocks, like rapeseed, the results confirm algae as an interesting alternative, provided that certain conditions for their cultivation, such as high process optimisation, nutrient recycling and use of renewable energy to meet input demand, are met. The study also assessed the area potentially needed for an algae production plant able to supply large volumes of raw material to an existing commercial biorefinery. The findings confirm the potential of this feedstock to mitigate land abandonment on the coasts of the Mediterranean basin

    Warps and correlations with intrinsic parameters of galaxies in the visible and radio

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    From a comparison of the different parameters of warped galaxies in the radio, and especially in the visible, we find that: a) No large galaxy (large mass or radius) has been found to have high amplitude in the warp, and there is no correlation of size/mass with the degree of asymmetry of the warp. b) The disc density and the ratio of dark to luminous mass show an opposing trend: smaller values give more asymmetric warps in the inner radii (optical warps) but show no correlation with the amplitude of the warp; however, in the external radii neither is there any correlation with the asymmetry. c) A third anticorrelation arises from a comparison of the amplitude and degree of asymmetry in the warped galaxies. Hence, it seems that very massive dark matter haloes have nothing to do with the formation of warps but only with the degree of symmetry in the inner radii, and are unrelated to the warp shape for the outermost radii. Denser discs show up the same dependence.Comment: 13 pages, 2 figures, accepted to be published in A&

    Interleukin-1 receptor antagonist mediates toll-like receptor 3-induced inhibition of trophoblast adhesion to endometrial cells in vitro

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    STUDY QUESTION Is interleukin-1 receptor antagonist (IL-1RA) involved in the toll-like receptor 3 (TLR 3)-induced inhibition of trophoblast cells' adhesion to endometrial cells in vitro? SUMMARY ANSWER IL-1RA mediates the TLR 3-induced inhibition of trophoblast cells' adhesion to endometrial cells in vitro. WHAT IS KNOWN ALREADY It is well documented that endometrial TLR 3 activation leads to impairment of trophoblast binding to endometrial cells in vitro. IL-1RA is known as an anti-implantation factor, as its injection significantly reduced implantation rates in mice by an effect on endometrial receptivity. STUDY DESIGN, SIZE, DURATION Poly I:C was used as a TLR3 specific ligand and endometrial cells were either treated or not with Poly I:C (treated versus control) in vitro. IL-1RA was applied to block IL-1 signal transduction. IL-1RA was knocked down by Accell Human IL1RN siRNA. Flagellin was used to stimulate TLR 5. SP600125 (JNK) was applied to inhibit the mitogen-activated protein kinases (MAPK) pathway. BAY11 -7082 was used to inhibit the nuclear factor-κB (NF-κB) pathway. The experiments were performed in three replicates on three separate days. PARTICIPANTS/MATERIALS, SETTING, METHODS An in vitro assay was developed using RL95-2 (an endometrial cell line) and JAr (a trophoblast cell line) cells. Initially, the production of IL-1RA in RL95-2 cells in response to TLR 3 activation was measured. To determine whether the TLR 3-induced inhibition of trophoblast binding was mediated through IL-1RA: (i) we evaluated the effect of IL-1RA on the attachment of trophoblast cells to endometrial cells; (ii) we knocked down TLR3-induced IL-1RA gene expression by IL-1RA Small interfering RNA (siRNA) and evaluated trophoblast attachment to endometrial cells. Finally, to clarify through which pathway TLR 3-induced inhibition of trophoblast binding occurs: (i) activation of NF-κB and MAPK was detected by transfecting the cells with secreted placental alkaline phosphatase reporter plasmids bearing promoter sequences for each transcription factor; (ii) the inhibitors for NF-κB and MAPK were used to block signaling; (iii) it was then investigated whether addition of these inhibitors could restore the TLR 3-induced impairment of trophoblast attachment to the endometrial cells. MAIN RESULTS AND THE ROLE OF CHANCE Our results showed that addition of polyinosinic:polycytidylic acid (Poly I:C) to RL95-2 cells significantly increased the production of IL-1RA (P < 0.05). Addition of human recombinant IL-1RA to RL95-2 cells remarkably decreased the adhesion rate of trophoblast cells to endometrial cells (P < 0.05). In addition, suppression of TLR3-induced IL-1RA gene expression in RL95-2 cells significantly restored trophoblast cells attachment to endometrial cells in the presence of Poly I:C (P < 0.05). Only TLR3 and not TLR5 induced MAPK activation (P < 0.05). TLR3 ligation did not affect NF-κB activation. Of NF-kB and MAPK inhibitors, only MAPK's inhibitor could achieve restoration of spheroid adhesion to endometrial cells (P < 0.05). LIMITATIONS, REASONS FOR CAUTION This study has been only done in vitro. Future in vivo studies will confirm our data. WIDER IMPLICATIONS OF THE FINDINGS The findings of this study have a potential clinical application in introducing IL-1RA as one of the diagnostic infertility markers in the endometrium, which can affect the process of embryo adhesion at the time of implantation. Moreover, based on the novel data obtained in the current study, blocking and regulating the MAPK pathway by its inhibitors can be used as a new strategy to prevent and treat virus-induced infertility cases in ART techniques. STUDY FUNDING/COMPETING INTEREST This study was partially funded by a Marie Curie IIF-253948 grant to I.C. and was partially funded by the author's institutions. The authors have no conflict of interest to declare

    Resolving galaxies in time and space: II: Uncertainties in the spectral synthesis of datacubes

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    In a companion paper we have presented many products derived from the application of the spectral synthesis code STARLIGHT to datacubes from the CALIFA survey, including 2D maps of stellar population properties and 1D averages in the temporal and spatial dimensions. Here we evaluate the uncertainties in these products. Uncertainties due to noise and spectral shape calibration errors and to the synthesis method are investigated by means of a suite of simulations based on 1638 CALIFA spectra for NGC 2916, with perturbations amplitudes gauged in terms of the expected errors. A separate study was conducted to assess uncertainties related to the choice of evolutionary synthesis models. We compare results obtained with the Bruzual & Charlot models, a preliminary update of them, and a combination of spectra derived from the Granada and MILES models. About 100k CALIFA spectra are used in this comparison. Noise and shape-related errors at the level expected for CALIFA propagate to 0.10-0.15 dex uncertainties in stellar masses, mean ages and metallicities. Uncertainties in A_V increase from 0.06 mag in the case of random noise to 0.16 mag for shape errors. Higher order products such as SFHs are more uncertain, but still relatively stable. Due to the large number statistics of datacubes, spatial averaging reduces uncertainties while preserving information on the history and structure of stellar populations. Radial profiles of global properties, as well as SFHs averaged over different regions are much more stable than for individual spaxels. Uncertainties related to the choice of base models are larger than those associated with data and method. Differences in mean age, mass and metallicity are ~ 0.15 to 0.25 dex, and 0.1 mag in A_V. Spectral residuals are ~ 1% on average, but with systematic features of up to 4%. The origin of these features is discussed. (Abridged)Comment: A&A, accepte

    A study of central galaxy rotation with stellar mass and environment

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    © 2017. The American Astronomical Society. All rights reserved. We present a pilot analysis of the influence of galaxy stellar mass and cluster environment on the probability of slow rotation in 22 central galaxies at mean redshift z = 0.07. This includes new integral-field observations of five central galaxies selected from the Sloan Digital Sky Survey, observed with the SPIRAL integral-field spectrograph on the Anglo-Australian Telescope. The composite sample presented here spans a wide range of stellar masses, 10.9 < log(M∗/M⊙)lt; 12.0, and are embedded in halos ranging from groups to clusters, 12.9 < log(M 200 Ṁ) < 15.6. We find a mean probability of slow rotation in our sample of P(SR) = 54 ± 7%. Our results show an increasing probability of slow rotation in central galaxies with increasing stellar mass. However, when we examine the dependence of slow rotation on host cluster halo mass, we do not see a significant relationship. We also explore the influence of cluster dominance on slow rotation in central galaxies. Clusters with low dominance are associated with dynamically younger systems. We find that cluster dominance has no significant effect on the probability of slow rotation in central galaxies. These results conflict with a paradigm in which halo mass alone predetermines central galaxy properties

    Pet ownership and cognitive decline in older people

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    Animals can have a positive influence on human health. However, it is not yet known whether pet ownership can prevent cognitive decline. Therefore, we aimed to investigate cross-sectional and prospective associations between pet ownership and cognitive function in a large, representative sample of older adults. Data were from the English Longitudinal Study of Ageing (ELSA) using data collected in wave 5 and six years later in wave 8. Pet ownership was categorized as no pet, dog, cat or other pet. Cognitive function was assessed using tests of verbal fluency (assessed by asking how many different animals the participants could name in 60 seconds) and memory (sum of immediate and delayed verbal recall). Multiple linear regression, adjusted for potential confounders, was used to test the associations between pet ownership and cognitive function. A total of 8291 people (mean age: 66.72 years) were included. In cross-sectional analyses, dog owners had better verbal fluency than individuals with no pet, but there was no significant difference between cat or other pet owners and those with no pet. In prospective analyses, dog owners had a significantly larger decline in recall than those with no pet, whilst cat owners had a significantly smaller decline in verbal fluency. These results provide some evidence to suggest that pet ownership may have positive effects on cognition in later life. However, benefits of pet ownership were not unilaterally observed across different types of pet and measures of cognitive function suggesting that further research is required

    Cutaneous Biology: In vivo blockade of pemphigus vulgaris acantholysis by inhibition of intracellular signal transduction cascades

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    Pemphigus vulgaris (PV) is an autoimmune disease characterized by mucocutaneous intraepithelial blisters and pathogenic autoantibodies against desmoglein 3. The mechanism of blister formation in pemphigus has not been defined; however, in vitro data suggest a role for activation of intracellular signalling cascades. OBJECTIVES: To investigate the contribution of these signalling pathways to the mechanism of PV IgG-induced acantholysis in vivo. METHODS: We used the passive transfer mouse model. Mice were injected with IgG fractions of sera from a patient with PV, with or without pretreatment with inhibitors of proteins that mediate intracellular signalling cascades. RESULTS: Inhibitors of tyrosine kinases, phospholipase C, calmodulin and the serine/threonine kinase protein kinase C prevented PV IgG-induced acantholysis in vivo. CONCLUSIONS: These observations strongly support the role of intracellular signalling cascades in the molecular mechanism of PV IgG-induced acantholysi

    Human Trophoblast Cells Modulate Endometrial Cells Nuclear Factor kappa B Response to Flagellin In Vitro

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    Background: Implantation is a complex process that requires a delicate cooperation between the immune and reproductive system. Any interference in the fine balance could result in embryo loss and infertility. We have recently shown that Toll-like receptor 5 activation results in a decrease of trophoblast cells binding to endometrial cells in an in vitro model of human implantation. However, little is known about the downstream signalling leading to the observed failure in implantation and the factors that modulate this immune response. Methods and Principal Findings: An in vitro model of embryo implantation was used to evaluate the effect of trophoblasts and flagellin on the activation of NF-kappa B in endometrial cells and whether TLR5-related in vitro implantation failure is signalled through NF-kappa B. We generated two different NF-kappa B reporting cell lines by transfecting either an immortalized endometrial epithelial cell line (hTERT-EECs) or a human endometrial carcinoma cell line (Ishikawa 3-H-12) with a plasmid containing the secreted alkaline phosphatase (SEAP) under the control of five NF-kappa B sites. The presence of trophoblast cells as well as flagellin increased NF-kappa B activity when compared to controls. The NF-kappa B activation induced by flagellin was further increased by the addition of trophoblast cells. Moreover, blocking NF-kappa B signalling with a specific inhibitor (BAY11-7082) was able to restore the binding ability of our trophoblast cell line to the endometrial monolayer. Conclusions: These are the first results showing a local effect of the trophoblasts on the innate immune response of the endometrial epithelium. Moreover, we show that implantation failure caused by intrauterine infections could be associated with abnormal levels of NF-kappa B activation. Further studies are needed to evaluate the target genes through which NF-kappa B activation after TLR5 stimulation lead to failure in implantation and the effect of the embryo on those genes. Understanding these pathways could help in the diagnosis and treatment of implantation failure cases
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