Petrography and petrology of the Hawaii Scientific Drilling Project lavas: Inferences from olivine phenocryst abundances and compositions

The Mauna Loa (ML) and Mauna Kea (MK) lavas recovered by the Hawaii Scientific Drilling Project (HSDP) include aphyric to highly olivine-phyric basalts. The average olivine phenocryst abundance in the reference suite of ML flows is 14.5 vol % (vesicle-free and weighted by the flow thickness), while the average abundances of olivine in the reference suites of the MK alkalic and tholeiitic basalts are 1.1 and 14.0 vol %, respectively. Plagioclase and augite phenocrysts are rare in the ML and MK tholeiites, but the MK alkalic basalts can have up to 4 vol % plagioclase phenocrysts. Strained olivine grains, thought to represent disaggregated dunite xenoliths from the cumulate pile within the magma chamber(s), are ubiquitous in the drill core lavas. These deformed grains can comprise up to 50 % of the modal olivine in a given rock. Olivine core compositions in the lavas span forsterite contents of 80.4–90.7 (median 88.8, ML tholeiites), 75.8–86.6 (median 85.8, MK alkalic basalts), and 76.3–90.5 (median 88.0 mol %, MK tholeiites). Olivines with core compositions in the range Fo_(89–90.5) are present in tholeiitic lavas with a wide range of whole-rock MgO contents (9–30 wt %). Strained and unstrained olivines completely overlap in composition as do the compositions of spinels (100*Cr/(Cr+Al) ∼59–72; Mg# = 100*Mg/(Mg+Fe^(2+)) ∼40–66) present as inclusions in the olivine phenocrysts. The presence of Fo_(90.5) olivine in the HSDP lavas requires magmas with ∼16 wt % MgO in the ML and MK plumbing systems. Rare dunite xenoliths are also present in the drill core lavas. While compositionally homogeneous within a given xenolith, the six xenoliths contain olivines that span a wide range of forsterite contents (78.3–89.2 mol %). Spinels in these xenoliths are chrome-rich, have Mg# between 31 and 66, and define two populations on the basis of TiO_2 contents. Whole-rock compositions for the ML and MK tholeiites define olivine control lines on MgO-oxide diagrams, and the relationship between whole-rock MgO and olivine phenocryst abundance in these lavas suggests that the lavas with >12 wt % MgO have accumulated olivine. Comparing the weighted bulk composition of all of the MK tholeiites in the drill core with a calculated parental magma suggests that, on average, the MK tholeiites entrained most of the olivine phenocrysts that crystallized from their parental liquids. Although deformed olivines in Hawaiian lavas are widely thought to represent disaggregated dunite xenoliths, none of the majoror minor-element data on the strained or unstrained olivine phenocrysts suggest that the strained olivines in the HSDP lavas are exotic. We suggest that most of the olivine phenocrysts in a given flow, whether strained or unstrained, are closely related to the evolved liquid that now forms the groundmass. This is consistent with observed correlations between isotopic systems measured on olivine separates (e.g., O, He) and isotopic systems dominated by groundmass (e.g., Nd, Pb)

The nitrate transporter family protein LjNPF8.6 controls the N-fixing nodule activity

N-fixing nodules are new organs formed on legume roots as a result of the beneficial interaction with soil bacteria, rhizobia. The nodule functioning is still a poorly characterized step of the symbiotic interaction, as only a few of the genes induced in N-fixing nodules have been functionally characterized. We present here the characterization of a member of the Lotus japonicus nitrate transporter1/peptide transporter family, LjNPF8.6. The phenotypic characterization carried out in independent L. japonicus LORE1 insertion lines indicates a positive role of LjNPF8.6 on nodule functioning, as knockout mutants display N-fixation deficiency (25%) and increased nodular superoxide content. The partially compromised nodule functioning induces two striking phenotypes: anthocyanin accumulation already displayed 4 weeks after inoculation and shoot biomass deficiency, which is detected by long-term phenotyping. LjNPF8.6 achieves nitrate uptake in Xenopus laevis oocytes at both 0.5 and 30 mm external concentrations, and a possible role as a nitrate transporter in the control of N-fixing nodule activity is discussed

Adaptive response of neonatal sepsis-derived Group B Streptococcus to bilirubin

This work was funded by the Neonatal Unit Endowment Fund, Aberdeen Maternity Hospital. RH is funded by a career researcher fellowship from NHS Research Scotland. SG was funded by the MRC Flagship PhD programme. We are grateful for the support of Dr Phil Cash and Aberdeen Proteomics, at University of Aberdeen, in completing this project. Supplementary information accompanies this paper at https://doi.org/10.1038/s41598-018-24811-3.Peer reviewedPublisher PD

Entre a dimensão formal e informal do aprendizado: a escrita de si como dispositivo de formação no contexto universitário

O presente artigo apresenta os resultados de um trabalho de produção narrativa reflexiva, realizado com estudantes do segundo ano de graduação do curso de ciências da educação, de uma universidade pública parisiense. Este trabalho foi realizado entre os anos de 2016 a 2018, no escopo do curs

Swiss stained-glass panels: an analytical study

The history and iconography of Swiss stained glass dating between the 16th and 18th centuries are well studied. However, the chemical and morphological characteristics of the glass and glass paints, particularly the nature of the raw materials, the provenance of the glass, and the technology used to produce it are less well understood. In this paper, we studied two sets of samples from stained-glass panels attributed to Switzerland, which date from the 16th to 17th centuries: the first set comes from Pena National Palace collection, the second from Vitrocentre Romont. The aims were to identify the materials used in the production of the glass, to find out more about their production origin and to characterize the glass paints. Both glass and the glass paints were analysed by particle-induced X-ray emission; the paints were additionally analysed by scanning electron microscopy–electron-dispersive X-ray spectroscopy (SEM-EDS). The results show that the glass from both sets was probably produced in the same region and that wood ash was used as a fluxing agent. Different recipes have been used to make the blue enamels. However, the cobalt ore used as a coloring agent in all of the blue enamels came from the mining district in Schneeberg, Germany

Echogenicity enhancement by end-fluorinated polylactide perfluorohexane nanocapsules: Towards ultrasound-activable nanosystems

International audienc

Utilisation des programmes de calcul pour introduire l'algèbre au collège

Dans cet article, nous rendons compte d'une partie du travail que nous fai-sons dans le cadre d'une recherche collaborative intitulée SESAMES (Situations d'Enseignement Scientifique : Activités de Modélisation, d'Evaluation, de Simulation) qui a pour but la production collaborative (par des enseignants et des chercheurs, chacun apportant une expertise dans son domaine) de ressources pour les enseignants et les formateurs de mathématiques favorisant la mise en activité des élèves et leur prise de responsabilité vis- à-vis des savoirs enseignés. Notre thème est celui de l'enseignement de l'algèbre au collège. Ces documents produits sont disponibles sur le site http://pegame.ens-lyon.fr/ Nous avons également travaillé dans le cadre du projet européen S-TEAM (Science Teacher Education Advanced Methods) qui vise à étudier l'évolution des pratiques des enseignants vers la mise en place des séances qui permettent aux élèves d'être plus actifs dans leurs apprentissages notamment en utilisant les démarches d'investigation ou des dispositifs proches

iPSC-derived neurospheroids recapitulate development and pathological signatures of human brain microenvironment

Brain microenvironment plays an important role in neurodevelopment and pathology, where extracellular matrix (ECM) and soluble factors modulate multiple cellular processes. Neural cell culture typically relies on the use of heterologous matrices that poorly resemble the brain ECM or reflect its pathological features. We have previously demonstrated that perfusion stirred-tank bioreactor-based 3D differentiation of human neural stem cells (NSC) - pSTR-neurospheroids, sustains the concomitant differentiation of the three neural cell lineages (neurons, astrocytes and oligodendrocytes) and the establishment of physiologically relevant cell-cell interactions. Here, we hypothesized that if the pSTR-neurospheroid strategy would also allow the deposition of native neural ECM components and diffusion of secreted factors, it would be possible to: (i) mimic the cellular and microenvironment remodeling occurring during neural differentiation without the confounding effects of exogenous matrices; (ii) recapitulate the pathological phenotypes of diseases in which alteration of homotypic and heterotypic cell-cell interactions and ECM components are relevant. To demonstrate the first point, we analyzed pSTR-neurospheroid differentiation by quantitative transcriptome (NGS) and proteome (SWATH-MS). Data showed that neurogenic developmental pathways were recapitulated, with significant changes at cell membrane and ECM composition, diverging from the 2D differentiation profile. A significant enrichment in structural proteoglycans typical of brain ECM, along with downregulation of basement membrane constituents was observed. Moreover, higher expression of synaptic and ion transport machinery in pSTR-neurospheroids suggest higher neuronal maturation than in 2D. Having shown recapitulation of neural microenvironmental dynamics in pSTR-neurospheroids, we used Mucopolysaccharidosis VII (MPSVII) as a disease case study. MPS VII is a lysosomal storage disease caused by deficient β-glucuronidase (β-gluc) activity, which leads to accumulation of glycosaminoglycans (GAGs) in many tissues, including the brain. In pSTR-neurospheroids generated from hiPSC of a MPS VII patient, the main molecular disease hallmarks were recapitulated, namely accumulation of GAGs. Notably, MPS VII neurospheroids showed reduced neuronal activity and a disturbance in network functionality, with alterations both in connectivity and synchronization, not observed in 2D cultures. These data provide insight into the interplay between reduced β-gluc activity, GAG accumulation, alterations in the neural network, and its impact on MPS VII-associated cognitive defects. Overall we demonstrate that neural cellular and extracellular developmental and pathological features are recapitulated in healthy and diseased pSTR-neurospheroids, respectively. These can be valuable in vitro models to address molecular defects associated with neurological disorders that affect neural microenvironment homeostasis. Moreover, the 3D neuronal connectivity assay developed is a new tool with potential to assess other lysosomal storage diseases and neurodegenerative diseases that have variable phenotypes. Acknowledgements: SFRH/BD/78308/2011, SFRH/BD/52202/2013 and SFRH/BD/52473/2014 PhD fellowships from FCT, Portugal and iNOVA4Health-UID/Multi/04462/2013, supported by FCT/ MEC, through national funds and co-funded by FEDER under the PT2020 Partnership Agreement