Multiple sulfur isotopic reservoirs in the Moon and implications for the evolution of planetary interiors

2020 ◽  
Author(s):  
Samantha Faircloth ◽  
Mahesh Anand ◽  
Ian Franchi ◽  
Xuchao Zhao ◽  
Sara Russell
Keyword(s):  
Late Stage ◽  
Secondary Ion Mass Spectrometry ◽  
Silicate Melts ◽  
The Moon ◽  
Edge Structure ◽  
Lunar Interior ◽  
Novel Approach ◽  
Sulfur Isotope Fractionation ◽  
First Time

Abstract Very few in situ lunar sulfur studies exist, with the major focus being on bulk-rocks in which a relatively restricted sulfur isotope fractionation is observed, leading to suggestions that the source of sulfur in the lunar interior is homogeneous. Using a novel approach, we present for the first time two complementary datasets combining in situ secondary ion mass spectrometry and X-ray absorption near-edge structure spectroscopy of lunar apatite, to investigate the late-stage behaviour of sulfur in lunar basaltic melts. Our measurements reveal varied sulfur contents of ~20–2,800 ppm and δ34S values of -33.3 ± 3.8‰ to +36.4 ± 3.2‰ (2σ). The apatites have S6+/ΣStot ratios of >0, with average values as high as 0.55, providing evidence for the existence of relatively oxidized late-stage silicate melts on the Moon. We propose the existence of multiple, previously unrecognised, distinct sulfur isotopic reservoirs in the lunar interior and atypical oxidizing conditions in late-stage silicate melts. These findings are important for our understanding of lunar formation processes and the evolution of redox conditions during the formation of terrestrial bodies.

The Total Synthesis of Rhabdastrellic Acid A

2018 ◽  
Author(s):  
Yaroslav Boyko ◽  
Christopher Huck ◽  
David Sarlah
Keyword(s):  
Total Synthesis ◽  
Late Stage ◽  
Cross Coupling ◽  
Side Chains ◽  
General Strategy ◽  
Modular Approach ◽  
Linear Sequence ◽  
Generating Sequence ◽  
First Time

<div>The first total synthesis of rhabdastrellic acid A, a highly cytotoxic isomalabaricane triterpenoid, has been accomplished in a linear sequence of 14 steps from commercial geranylacetone. The prominently strained <i>trans-syn-trans</i>-perhydrobenz[<i>e</i>]indene core characteristic of the isomalabaricanes is efficiently accessed in a selective manner for the first time through a rapid, complexity-generating sequence incorporating a reductive radical polyene cyclization, an unprecedented oxidative Rautenstrauch cycloisomerization, and umpolung 𝛼-substitution of a <i>p</i>-toluenesulfonylhydrazone with in situ reductive transposition. A late-stage cross-coupling in concert with a modular approach to polyunsaturated side chains renders this a general strategy for the synthesis of numerous family members of these synthetically challenging and hitherto inaccessible marine triterpenoids.</div>

Direct visualization of a vast cortical calcium compartment in Paramecium by secondary ion mass spectrometry (SIMS) microscopy: possible involvement in exocytosis

1995 ◽  
Vol 108 (5) ◽  
pp. 1895-1909 ◽  
Author(s):  
N. Stelly ◽  
S. Halpern ◽  
G. Nicolas ◽  
P. Fragu ◽  
A. Adoutte
Keyword(s):  
Mass Spectrometry ◽  
Secondary Ion Mass Spectrometry ◽  
Membrane Vesicles ◽  
Cell Periphery ◽  
A Value ◽  
External Reference ◽  
Ion Mass Spectrometry ◽  
First Time ◽  
Secondary Ion

The plasma membrane of ciliates is underlaid by a vast continuous array of membrane vesicles known as cortical alveoli. Previous work had shown that a purified fraction of these vesicles actively pumps calcium, suggesting that alveoli may constitute a calcium-storage compartment. Here we provide direct confirmation of this hypothesis using in situ visualization of total cell calcium on sections of cryofixed and cryosubstituted cells analyzed by SIMS (secondary ion mass spectrometry) microscopy a method never previously applied to protists. A narrow, continuous, Ca-emitting zone located all along the cell periphery was observed on sections including the cortex. In contrast, Na and K were evenly distributed throughout the cell. Various controls confirmed that emission was from the alveoli, in particular, the emitting zone was still seen in mutants totally lacking trichocysts, the large exocytotic organelles docked at the cell surface, indicating that they make no major direct contribution to the emission. Calcium concentration within alveoli was quantified for the first time in SIMS microscopy using an external reference and was found to be in the range of 3 to 5 mM, a value similar to that for sarcoplasmic reticulum. After massive induction of trichocyst discharge, this concentration was found to decrease by about 50%, suggesting that the alveoli are the main source of the calcium involved in exocytosis.

scholarly journals The New Moon: Major Advances in Lunar Science Enabled by Compositional Remote Sensing from Recent Missions

Geosciences ◽  
2018 ◽  
Vol 8 (12) ◽  
pp. 498
Author(s):  
Deepak Dhingra
Keyword(s):  
Rapid Evolution ◽  
The Moon ◽  
New Paradigm ◽  
Lunar Science ◽  
Lunar Interior ◽  
New Findings ◽  
Lunar Samples ◽  
Resource Exploration ◽  
Globally Distributed

Volatile-bearing lunar surface and interior, giant magmatic-intrusion-laden near and far side, globally distributed layer of purest anorthosite (PAN) and discovery of Mg-Spinel anorthosite, a new rock type, represent just a sample of the brand new perspectives gained in lunar science in the last decade. An armada of missions sent by multiple nations and sophisticated analyses of the precious lunar samples have led to rapid evolution in the understanding of the Moon, leading to major new findings, including evidence for water in the lunar interior. Fundamental insights have been obtained about impact cratering, the crystallization of the lunar magma ocean and conditions during the origin of the Moon. The implications of this understanding go beyond the Moon and are therefore of key importance in solar system science. These new views of the Moon have challenged the previous understanding in multiple ways and are setting a new paradigm for lunar exploration in the coming decade both for science and resource exploration. Missions from India, China, Japan, South Korea, Russia and several private ventures promise continued exploration of the Moon in the coming years, which will further enrich the understanding of our closest neighbor. The Moon remains a key scientific destination, an active testbed for in-situ resource utilization (ISRU) activities, an outpost to study the universe and a future spaceport for supporting planetary missions.

scholarly journals Precise in situ etch depth control of multilayered III−V semiconductor samples with reflectance anisotropy spectroscopy (RAS) equipment

2016 ◽  
Vol 7 ◽  
pp. 1783-1793 ◽  
Author(s):  
Ann-Kathrin Kleinschmidt ◽  
Lars Barzen ◽  
Johannes Strassner ◽  
Christoph Doering ◽  
Henning Fouckhardt ◽  
...  
Keyword(s):  
Secondary Ion Mass Spectrometry ◽  
Semiconductor Device ◽  
Device Fabrication ◽  
Etch Depth ◽  
Reflectance Anisotropy ◽  
Depth Control ◽  
Dry Etch ◽  
First Time ◽  
Secondary Ion

Reflectance anisotropy spectroscopy (RAS) equipment is applied to monitor dry-etch processes (here specifically reactive ion etching (RIE)) of monocrystalline multilayered III–V semiconductors in situ. The related accuracy of etch depth control is better than 16 nm. Comparison with results of secondary ion mass spectrometry (SIMS) reveals a deviation of only about 4 nm in optimal cases. To illustrate the applicability of the reported method in every day settings for the first time the highly etch depth sensitive lithographic process to form a film lens on the waveguide ridge of a broad area laser (BAL) is presented. This example elucidates the benefits of the method in semiconductor device fabrication and also suggests how to fulfill design requirements for the sample in order to make RAS control possible.

The Total Synthesis of Rhabdastrellic Acid A

2018 ◽  
Author(s):  
Yaroslav Boyko ◽  
Christopher Huck ◽  
David Sarlah
Keyword(s):  
Total Synthesis ◽  
Late Stage ◽  
Cross Coupling ◽  
Side Chains ◽  
General Strategy ◽  
Modular Approach ◽  
Linear Sequence ◽  
Generating Sequence ◽  
First Time

<div>The first total synthesis of rhabdastrellic acid A, a highly cytotoxic isomalabaricane triterpenoid, has been accomplished in a linear sequence of 14 steps from commercial geranylacetone. The prominently strained <i>trans-syn-trans</i>-perhydrobenz[<i>e</i>]indene core characteristic of the isomalabaricanes is efficiently accessed in a selective manner for the first time through a rapid, complexity-generating sequence incorporating a reductive radical polyene cyclization, an unprecedented oxidative Rautenstrauch cycloisomerization, and umpolung 𝛼-substitution of a <i>p</i>-toluenesulfonylhydrazone with in situ reductive transposition. A late-stage cross-coupling in concert with a modular approach to polyunsaturated side chains renders this a general strategy for the synthesis of numerous family members of these synthetically challenging and hitherto inaccessible marine triterpenoids.</div>

scholarly journals Linking Microbial Phylogeny to Metabolic Activity at the Single-Cell Level by Using Enhanced Element Labeling-Catalyzed Reporter Deposition Fluorescence In Situ Hybridization (EL-FISH) and NanoSIMS

2008 ◽  
Vol 74 (10) ◽  
pp. 3143-3150 ◽  
Author(s):  
Sebastian Behrens ◽  
Tina Lösekann ◽  
Jennifer Pett-Ridge ◽  
Peter K. Weber ◽  
Wing-On Ng ◽  
...  
Keyword(s):  
In Situ Hybridization ◽  
Fluorescence In Situ Hybridization ◽  
Metabolic Activity ◽  
Secondary Ion Mass Spectrometry ◽  
Single Cells ◽  
Target Cells ◽  
Filamentous Cyanobacterium ◽  
Novel Approach ◽  
Catalyzed Reporter Deposition

ABSTRACT To examine phylogenetic identity and metabolic activity of individual cells in complex microbial communities, we developed a method which combines rRNA-based in situ hybridization with stable isotope imaging based on nanometer-scale secondary-ion mass spectrometry (NanoSIMS). Fluorine or bromine atoms were introduced into cells via 16S rRNA-targeted probes, which enabled phylogenetic identification of individual cells by NanoSIMS imaging. To overcome the natural fluorine and bromine backgrounds, we modified the current catalyzed reporter deposition fluorescence in situ hybridization (FISH) technique by using halogen-containing fluorescently labeled tyramides as substrates for the enzymatic tyramide deposition. Thereby, we obtained an enhanced element labeling of microbial cells by FISH (EL-FISH). The relative cellular abundance of fluorine or bromine after EL-FISH exceeded natural background concentrations by up to 180-fold and allowed us to distinguish target from non-target cells in NanoSIMS fluorine or bromine images. The method was optimized on single cells of axenic Escherichia coli and Vibrio cholerae cultures. EL-FISH/NanoSIMS was then applied to study interrelationships in a dual-species consortium consisting of a filamentous cyanobacterium and a heterotrophic alphaproteobacterium. We also evaluated the method on complex microbial aggregates obtained from human oral biofilms. In both samples, we found evidence for metabolic interactions by visualizing the fate of substrates labeled with 13C-carbon and 15N-nitrogen, while individual cells were identified simultaneously by halogen labeling via EL-FISH. Our novel approach will facilitate further studies of the ecophysiology of known and uncultured microorganisms in complex environments and communities.

In Situ Characterization of Superficial Organic Composition Changes of Thermoacidophilic Archaea Acidianus manzaensis YN-25 in Response to Energy Substrate

2017 ◽  
Vol 262 ◽  
pp. 417-420
Author(s):  
Li Zhu Liu ◽  
Xuan Pan ◽  
Xu Xia ◽  
Yu Hang Zhou ◽  
Zhen Yuan Nie ◽  
...  
Keyword(s):  
Extracellular Polymeric Substances ◽  
Iron Oxidation ◽  
Energy Substrates ◽  
Edge Structure ◽  
Organic Composition ◽  
Thermoacidophilic Archaea ◽  
Acidianus Manzaensis ◽  
First Time

The differences of superficial (about 10 nm) extracellular polymeric substances (EPS) composition of thermoacidophilic archaea Acidianus manzaensis YN-25 acclimated with different energy substrates (FeS2, CuFeS2, S0, FeSO4) were analyzed in situ for the first time by synchrotron radiation (SR) based carbon K-edge X-ray absorption near edge structure (XANES) spectroscopy. The results showed that there are clear associations between the energy substrates and the changes in organic composition in terms of typical function groups (-C=O, -C-O and -C-N). The archaea acclimated with chalcopyrite and pyrite contain higher proportion of proteins but less polysaccharides compared to cells acclimated with S0.The archaea acclimated with FeSO4 contains the highest proportion of protein which is positively associated with the iron oxidation process, while archaea acclimated with S0 contains more lipids and polysaccharides, which may be favorable to the hydrophobic S0 adsorption and utilization processes.

scholarly journals ElectroMagnetic Music: a new tool for attracting people interest in Geosciences, while sensitizing them to planet sustainability

2020 ◽  
Author(s):  
Antonio Menghini ◽  
Stefano Pontani ◽  
Vincenzo Sapia ◽  
Tiziana Lanza
Keyword(s):  
Eddy Currents ◽  
Voltage Response ◽  
Positive Feedbacks ◽  
Transient Electromagnetic ◽  
Novel Approach ◽  
Evaluation Phase ◽  
The World ◽  
Em Field ◽  
First Time

Abstract. EMusic stands for ElectroMagnetic Music and it is a scientific-musical project born in Italy. The idea is to transform the voltage response collected by Transient ElectroMagnetic Method (TEM), a well-known geophysical tool for exploring the subsurface, into musical pitches. This novel approach enables to extract musical pieces, reflecting the effective geological setting, so that we can claim that any site can be represented by its own soundtrack (i.e. the soundscape, the audio component of a landscape). As a consequence, it is possible to compose musical tracks describing faithfully the risk and many other geological issues related to different environmental scenarios. Since the beginning, a band of musicians experimented the EMusic giving concerts all over the world covering different geological locations. The sound representing each scenario was recovered in situ with the above-mentioned methodology. Some excerpts of the concerts have been also reproduced in a couple of occasions during the EGU General Assembly. Other experiments involved EMusic as a soundscape for enhancement of archaeological (Ancient Roman Theater of Ferento) and geo-touristic sites (Viterbo Underground and Vesuvius Volcano). The events were the occasion for sensitizing people about Volcanism, Volcanic risk, Paleontology, Climatic changes, Earthquakes and so on. During the concerts geoscientists introduce every track, by preparing the audience about what they are going to listen. The audience can experience a journey into the Earth by riding the eddy currents produced by the EM field. Not only it is a travel in space, but also in time, as we explore through EMusic older and older geological formations. The various musical-scientific performances – based on the sonification of EM data collected in different parts of the World including Italy – obtained positive feedbacks from the audience that enjoyed the shows. We are also implementing a project, named Georisonanze, to bring the EMusic in secondary schools to introduce students to the investigation of Earth with modern techniques while sensitizing them to planet sustainability. For the first time, we preview to pass to an evaluation phase, to better understand its intrinsic potential, through targeted tools.

scholarly journals Large sulfur isotope fractionation in lunar volcanic glasses reveals the magmatic differentiation and degassing of the Moon

2021 ◽  
Vol 7 (9) ◽  
pp. eabe4641
Author(s):  
Alberto E. Saal ◽  
Erik H. Hauri
Keyword(s):  
Sulfur Isotope ◽  
Melt Inclusions ◽  
Isotope Composition ◽  
The Moon ◽  
Magmatic Differentiation ◽  
Sulfur Isotope Fractionation ◽  
Volcanic Glasses ◽  
Sulfur Isotope Composition ◽  
Lunar Core

Sulfur isotope variations in mantle-derived lavas provide important constraints on the evolution of planetary bodies. Here, we report the first in situ measurements of sulfur isotope ratios dissolved in primitive volcanic glasses and olivine-hosted melt inclusions recovered from the Moon by the Apollo 15 and 17 missions. The new data reveal large variations in 34S/32S ratios, which positively correlates with sulfur and titanium contents within and between the distinct compositional groups of volcanic glasses analyzed. Our results uncover several magmatic events that fractionated the primordial sulfur isotope composition of the Moon: the segregation of the lunar core and the crystallization of the lunar magma ocean, which led to the formation of the heterogeneous sources of the lunar magmatism, followed by magma degassing during generation, transport, and eruption of the lunar lavas. Whether the Earth’s and Moon’s interiors share a common 34S/32S ratio remains a matter of debate.

scholarly journals In situ X-ray absorption near edge structure studies and charge transfer kinetics of Na6[V10O28] electrodes

2017 ◽  
Vol 19 (4) ◽  
pp. 3358-3365 ◽  
Author(s):  
Han-Yi Chen ◽  
Jochen Friedl ◽  
Chun-Jern Pan ◽  
Ali Haider ◽  
Rami Al-Oweini ◽  
...  
Keyword(s):  
Electron Transfer ◽  
Charge Transfer ◽  
Absorption Spectroscopy ◽  
Edge Structure ◽  
X Ray ◽  
First Time ◽  
X Ray Absorption ◽  
Kinetics Of

The electron transfer of Na6[V10O28] was investigated byin situV K-edge X-ray absorption spectroscopy and chronoamperometric experiments for the first time.

Sign in / Sign up

Export Citation Format

Share Document