Apparent Splitting of S Waves Propagating Through an Isotropic Lowermost Mantle

Observations of shear wave anisotropy are key for understanding the mineralogical structure and flow in the mantle. Several researchers have reported the presence of seismic anisotropy in the lowermost 150–250 km of the mantle (i.e., D urn:x-wiley:jgrb:media:jgrb52636:jgrb52636-math-0002 layer), based on differences in the arrival times of vertically (SV) and horizontally (SH) polarized shear waves. By computing waveforms at a period > 6 s for a wide range of 1‐D and 3‐D Earth structures, we illustrate that a time shift (i.e., apparent splitting) between SV and SH may appear in purely isotropic simulations. This may be misinterpreted as shear wave anisotropy. For near‐surface earthquakes, apparent shear wave splitting can result from the interference of S with the surface reflection sS. For deep earthquakes, apparent splitting can be due to the S wave triplication in D urn:x-wiley:jgrb:media:jgrb52636:jgrb52636-math-0003, reflections off discontinuities in the upper mantle, and 3‐D heterogeneity. The wave effects due to anomalous isotropic structure may not be easily distinguished from purely anisotropic effects if the analysis does not involve full waveform simulations

Chlorophylls extraction from spinach leaves using aqueous solutions of surface-active ionic liquids

Chlorophylls and their derivatives have been extensively studied due to their unique and valuable properties, including their anti-mutagenic and anti-carcinogenic features. Nevertheless, high-purity-level chlorophylls extracted from natural sources are quite expensive because the methods used for their extraction have low selectivity and result in low yields. This study aimed to develop a “greener” and cost-effective technology for the extraction of chlorophylls from biomass using aqueous solutions of ionic liquids (ILs). Several aqueous solutions of ILs, with hydrotropic and surface-active effects were evaluated, demonstrating that aqueous solutions of surface-active ILs are enhanced solvents for the extraction of chlorophylls from spinach leaves. Operating conditions, such as the IL concentration and solid–liquid ratio, were optimized by a response surface methodology. Outstanding extraction yields (0.104 and 0.022 wt.% for chlorophyll a and b, respectively, obtained simultaneously) and selectivity (chlorophyll a/b ratio of 4.79) were obtained with aqueous solutions of hexadecylpyridinium chloride ([C16py]Cl) at moderate conditions of temperature and time. These extraction yields are similar to those obtained with pure ethanol. However, the chlorophyll a/b ratio achieved with the IL aqueous solution is higher than with pure ethanol (3.92), reinforcing the higher selectivity afforded by IL aqueous solutions as viable replacements to volatile organic compounds and allowing the obtainment of more pure compounds. Finally, the recovery and reuse of the solvent were evaluated by using a back-extraction step of chlorophylls using ethyl acetate. The results disclosed here bring new perspectives into the design of new approaches for the selective extraction of chlorophylls from biomass using aqueous solutions of surface-active ILspublishe

Efficient extraction of the RuBisCO enzyme from spinach leaves using aqueous solutions of biocompatible ionic liquids

Ribulose-1,5-biphosphate carboxylase/oxygenase (RuBisCO) is the most abundant protein on the planet, being present in plants, algae and various species of bacteria, with application in the pharmaceutical, chemical, cosmetic and food industries. However, current extraction methods of RuBisCO do not allow high yields of extraction. Therefore, the development of an efficient and selective RuBisCOs’ extraction method is required. In this work, aqueous solutions of biocompatible ionic liquids (ILs), i.e., ILs derived from choline and analogues of glycine-betaine, were applied in the RuBisCO’s extraction from spinach leaves. Three commercial imidazolium-based ILs were also investigated for comparison purposes. To optimize RuBisCO’s extraction conditions, response surface methodology was applied. Under optimum extraction conditions, extraction yields of 10.92 and 10.57 mg of RuBisCO/g of biomass were obtained with the ILs cholinium acetate ([Ch][Ac]) and cholinium chloride ([Ch]Cl), respectively. Circular dichroism (CD) spectroscopy results show that the secondary structure of RuBisCO is better preserved in the IL solutions when compared to the commonly used extraction solvent. The obtained results indicate that cholinium-based ILs are a promising and viable alternative for the extraction of RuBisCO from vegetable biomass.publishe

Sparse Bayesian mass-mapping using trans-dimensional MCMC

Uncertainty quantification is a crucial step of cosmological mass-mapping that is often ignored. Suggested methods are typically only approximate or make strong assumptions of Gaussianity of the shear field. Probabilistic sampling methods, such as Markov chain Monte Carlo (MCMC), draw samples form a probability distribution, allowing for full and flexible uncertainty quantification, however these methods are notoriously slow and struggle in the high-dimensional parameter spaces of imaging problems. In this work we use, for the first time, a trans-dimensional MCMC sampler for mass-mapping, promoting sparsity in a wavelet basis. This sampler gradually grows the parameter space as required by the data, exploiting the extremely sparse nature of mass maps in wavelet space. The wavelet coefficients are arranged in a tree-like structure, which adds finer scale detail as the parameter space grows. We demonstrate the trans-dimensional sampler on galaxy cluster-scale images where the planar modelling approximation is valid. In high-resolution experiments, this method produces naturally parsimonious solutions, requiring less than 1% of the potential maximum number of wavelet coefficients and still producing a good fit to the observed data. In the presence of noisy data, trans-dimensional MCMC produces a better reconstruction of mass-maps than the standard smoothed Kaiser-Squires method, with the addition that uncertainties are fully quantified. This opens up the possibility for new mass maps and inferences about the nature of dark matter using the new high-resolution data from upcoming weak lensing surveys such as Euclid

Volatile composition and sensory properties of mead

Mead is a traditional beverage that results from the alcoholic fermentation of diluted honey performed by yeasts. Although the process of mead production has been optimized in recent years, studies focused on its sensory properties are still scarce. Therefore, the aim of this work was to analyse the sensory ttributes of mead produced with free or immobilized cells of the Saccharomyces cerevisiae strains QA23 and ICV D47, and to establish potential correlations with its olatile composition. In the volatile composition of mead, the effect of yeast condition was more important than the strain. In respect to sensory analysis, the most pleasant aroma descriptors were correlated with mead obtained with free yeast cells, independently of the strain. Both sensory analysis and volatile composition indicates that the most pleasant mead was produced by free yeast cells. Although this study has provided a significant contribution, further research on the sensory quality of mead is still needed.Portuguese Foundation for Science and Technology (FCT) through a PhD grant (SFRH/BD/45820/2008). This research was partially supported through the PTDC project (PTDC/AGR-ALI/68284/2006) awarded by the FCT. This study was supported by the Portuguese Foundation for Science and Technology (FCT) under the scope of the strategic funding of UID/BIO/04469/2013 unit and COMPETE 2020 (POCI-01-0145-FEDER-006684) and BioTecNorte operation (NORTE-01-0145-FEDER-000004) funded by European Regional Development Fund under the scope of Norte2020 – Programa Operacional Regional do Norteinfo:eu-repo/semantics/publishedVersio

Ubiquitous lower-mantle anisotropy beneath subduction zones

Seismic anisotropy provides key information to map the trajectories of mantle flow and understand the evolution of our planet. While the presence of anisotropy in the uppermost mantle is well established, the existence and nature of anisotropy in the transition zone and uppermost lower mantle are still debated. Here we use three-dimensional global seismic tomography images based on a large dataset that is sensitive to this region to show the ubiquitous presence of anisotropy in the lower mantle beneath subduction zones. Whereas above the 660 km seismic discontinuity slabs are associated with fast SV anomalies up to about 3%, in the lower mantle fast SH anomalies of about 2% persist near slabs down to about 1,000–1,200 km. These observations are consistent with 3D numerical models of deformation from subducting slabs and the associated lattice-preferred orientation of bridgmanite produced in the dislocation creep regime in areas subjected to high stresses. This study provides evidence that dislocation creep may be active in the Earth’s lower mantle, providing new constraints on the debated nature of deformation in this key, but inaccessible, component of the deep Earth

Sustainable liquids support as a media for biocatalytic reactions using aqueous biphasic systems

Over the last few years a significant interest in the application of biocatalyst in several industries as an alternative to the commonly used chemical biocatalyst has emerged, since enzymes, such as laccase, allow for an improved, sustainable and biodegradable catalytic process partially due to their high specificity to its substrates. Nevertheless, its application can still be considered a costly process thus to overcome this shortcoming emerges the need for the enzyme reutilization employed in the catalytic reaction 1. One of the alternatives is to implement aqueous biphasic systems (ABS), which are a biocompatible liquid-liquid extraction as a liquid support. Moreover, the introduction of ionic liquids (ILs) in ABS have shown promising results in the system overall performance and could potentially allow for an improved biocatalyst performance. Therefore, our goal was to form an ABS composed of cholinium-based ILs and polypropylene glycol (PPG 400) as novel liquid supports for enzymes, using laccase as models in order to evaluated the degradation of the textile dye Remazol Brilliant Blue R (RBBR) as well as the capacity to reutilized the biocatalyst for further applications.publishe

New fluorescent heterocyclic materials: Synthesis, solvatochromic and fluorescence properties

Thienyl- and bithienyl-1,3-benzothiazoles 1 and 2 were synthesised by reacting various formyl thienyl and bithienyl derivatives with o-aminobenzenethiol in moderate to excellent yields. Evaluation of the solvatochromic and fluorescence properties of these compounds was carried out. Due to their strong fluorescence and also the strong push-pull character, benzothiazole derivatives 1 and 2 can be used as potential NLO materials or as fluorescent markers.Fundação para a Ciência e Tecnologia (FCT

A study of the antitumour potential of three Portuguese wild mushrooms

Natural matrixes such as mushrooms represent a rich source of biologically active compounds with recognized potential in drug discovery and development [1,2]. Indeed, many pre-clinical studies have been conducted in human tumour cell lines and in some cases, a number of compounds extracted from mushrooms have entered clinical trials [3]. Our previous results showed that extracts from Agaricus arvensis, Suillus collinitus and Clytocibe alexandri are promising sources of low molecular weight bioactive compounds [4]. The aim of the present work was to study the antitumour potential of the extracts and isolated compounds from three Portuguese wild mushrooms by verifying their effect on various human tumour cell lines in what concerns effect on cell growth, cell cycle profile and programmed cell death. Wild mushrooms were collected from the Northeast of Portugal and classified as Agaricus arvensis, Suillus collinitus and Clitocybe alexandri. Phenolic (methanolic and ethanolic) and polissacharidic extracts were prepared. The effect of the extracts on tumour cell growth inhibition was verified with the SRB assay and the GI50 of each extract was determined for each of the cell lines studied (NCI-H460, MCF-7, AGS and HCT-15). Our preliminary results revealed that all the extracts from Clitocybe alexandri are capable of causing cell growth inhibition and provided GI50 concentrations bellow 60µg/ml in all the cell lines tested [4]. Regarding the effect of the Agaricus arvensis extracts, they all caused an inhibition of cell growth in all cell lines, particularly the methanolic extract which revealed to be a very potent inhibitor of cell growth, especially in the MCF-7 cell line. The evaluation of the effect of the Suillus collinitus extracts will be carried out as well as cell cycle and apoptosis analyses, by flow cytometry. Finally, the isolation and characterization of compounds from these extracts will also be carried out, using HPLC-DAD or HPLC-RI. The structures of the compounds will be established by NMR spectral analysis (1H, 13C, DEPT, COSY, HSQC and HMBC).FCT and COMPETE/QREN/UE- project PTDC/AGR-ALI/110062/200

Heterogeneous seismic anisotropy beneath Madeira and Canary archipelagos revealed by local and teleseismic shear wave splitting

Mid-plate upward mantle flow is a key component of global mantle convection, but its patterns are poorly constrained. Seismic anisotropy is the most direct way to infer mantle flow as well as melt distribution, yet the convection patterns associated with plume-like mantle upwelling are understudied due to limited seismic data coverage. Here, we investigate seismic anisotropy beneath the Madeira and Canary hotspots using a dense set of shear wave splitting observations and combining teleseismic and local events recorded by three-component broad-band and short-period seismic stations. Using a total of 26 stations in the Madeira archipelago and 43 stations around the Canary Islands, we obtain 655 high-quality measurements that reveal heterogeneous flow patterns. Although local event results are sparse around most islands, we can observe a small average of S-wave splitting times of 0.16 ± 0.01 s, which significantly increase with source depth beneath El Hierro (>20 km) and Tenerife (>38 km) up to 0.58 ± 0.01 and 0.47 ± 0.05 s. This suggests an influence of melt pocket orientation in magma reservoirs developed at uppermost-mantle depths. Likewise, anisotropy increases significantly beneath the islands with shield stage volcanism (up to 9.81 ± 1.78 per cent at El Hierro, western Canaries, against values up to 1.76 ± 0.73 per cent at Lanzarote, eastern Canaries). On average, teleseismic SKS-wave splitting delay times are large (2.19 ± 0.05 s), indicating sublithospheric mantle flow as the primary source for anisotropy in the region. In the Canaries, the western islands show significantly smaller average SKS delay times (1.93 ± 0.07 s) than the eastern ones (2.25 ± 0.11 s), which could be explained by destructive interference above the mantle upwelling. Despite complex patterns of fast polarization directions throughout both regions, some azimuthal pattern across close stations can be observed and related to present- day mantle flow and anisotropy frozen in the lithosphere since before 60 Ma. Additionally, we infer that the current presence of a mantle plume beneath the archipelagos leads to the associated complex, small-scale heterogeneous anisotropy observations.info:eu-repo/semantics/publishedVersio