Finding of primary basalt from Sannome-gata volcano, northeastern Japan, and its compositional variation.

AbstractDiversity of the gut microbiome is associated with higher response rates for cancer patients receiving immunotherapy but has not been investigated in patients receiving radiation therapy. Additionally, current studies investigating the gut microbiome and outcomes in cancer patients may not have adjusted for established risk factors. Here, we sought to determine if diversity and composition of the gut microbiome was independently associated with survival in cervical cancer patients receiving chemoradiation. Our study demonstrates that the diversity of gut microbiota is associated with a favorable response to chemoradiation. Additionally, compositional variation among patients correlated with short term and long-term survival. Short term survivor fecal samples were significantly enriched in Porphyromonas, Porphyromonadaceae, and Dialister, whereas long term survivor samples were significantly enriched in Escherichia Shigella, Enterobacteriaceae, and Enterobacteriales. Moreover, analysis of immune cells from cervical tumor brush samples by flow cytometry revealed that patients with a high microbiome diversity had increased tumor infiltration of CD4+ lymphocytes as well as activated subsets of CD4 cells expressing ki67+ and CD69+ over the course of radiation therapy. Modulation of the gut microbiota before chemoradiation might provide an alternative way to enhance treatment efficacy and improve treatment outcomes in cervical cancer patients.

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The Evolution of Isochores: Evidence From SNP Frequency Distributions

Genetics ◽

10.1093/genetics/162.4.1805 ◽

2002 ◽

Vol 162 (4) ◽

pp. 1805-1810 ◽

Cited By ~ 1

Author(s):

Martin J Lercher ◽

Nick G C Smith ◽

Adam Eyre-Walker ◽

Laurence D Hurst

Keyword(s):

Population Genetics ◽

Large Scale ◽

Gc Content ◽

Nucleotide Composition ◽

Compositional Variation ◽

Mutation Bias ◽

Single Nucleotide ◽

Frequency Distributions ◽

Noncoding Regions ◽

Standard Population

AbstractThe large-scale systematic variation in nucleotide composition along mammalian and avian genomes has been a focus of the debate between neutralist and selectionist views of molecular evolution. Here we test whether the compositional variation is due to mutation bias using two new tests, which do not assume compositional equilibrium. In the first test we assume a standard population genetics model, but in the second we make no assumptions about the underlying population genetics. We apply the tests to single-nucleotide polymorphism data from noncoding regions of the human genome. Both models of neutral mutation bias fit the frequency distributions of SNPs segregating in low- and medium-GC-content regions of the genome adequately, although both suggest compositional nonequilibrium. However, neither model fits the frequency distribution of SNPs from the high-GC-content regions. In contrast, a simple population genetics model that incorporates selection or biased gene conversion cannot be rejected. The results suggest that mutation biases are not solely responsible for the compositional biases found in noncoding regions.

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Compositional flexibility in Li-N-H materials: implications for ammonia catalysis and hydrogen storage.

Physical Chemistry Chemical Physics ◽

10.1039/d1cp02440j ◽

2021 ◽

Author(s):

Joshua Makepeace ◽

Jake M Brittain ◽

Alisha Sukhwani Manghnani ◽

Claire Murray ◽

Thomas J Wood ◽

...

Keyword(s):

Energy Storage ◽

Hydrogen Storage ◽

Compositional Variation ◽

Lithium Amide ◽

Lithium Imide ◽

Energy Storage Applications

Li-N-H materials, particularly lithium amide and lithium imide, have been explored for use in a variety of energy storage applications in recent years. Compositional variation within the parent lithium imide,...

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Compositional Variation of Eudialyte-Group Minerals from the Lovozero and Ilímaussaq Complexes and on the Origin of Peralkaline Systems

Minerals ◽

10.3390/min11060548 ◽

2021 ◽

Vol 11 (6) ◽

pp. 548

Author(s):

Lia N. Kogarko ◽

Troels F. D. Nielsen

Keyword(s):

Linear Trend ◽

Major And Trace Elements ◽

High Tech ◽

Compositional Variation ◽

Elemental Distribution ◽

Magma Chambers ◽

Eudialyte Group ◽

System A ◽

Distribution Of Elements ◽

World Class

The Lovozero complex, Kola peninsula, Russia and the Ilímaussaq complex in Southwest Greenland are the largest known layered peralkaline intrusive complexes. Both host world-class deposits rich in REE and other high-tech elements. Both complexes expose spectacular layering with horizons rich in eudialyte group minerals (EGM). We present a detailed study of the composition and cryptic variations in cumulus EGM from Lovozero and a comparison with EGM from Ilímaussaq to further our understanding of peralkaline magma chambers processes. The geochemical signatures of Lovozero and Ilímaussaq EGM are distinct. In Lovozero EGMs are clearly enriched in Na + K, Mn, Ti, Sr and poorer Fe compared to EGM from Ilímaussaq, whereas the contents of ΣREE + Y and Cl are comparable. Ilímaussaq EGMs are depleted in Sr and Eu, which points to plagioclase fractionation and an olivine basaltic parent. The absence of negative Sr and Eu anomalies suggest a melanephelinitic parent for Lovozero. In Lovozero the cumulus EGMs shows decrease in Fe/Mn, Ti, Nb, Sr, Ba and all HREE up the magmatic layering, while REE + Y and Cl contents increase. In Lovozero EGM spectra show only a weak enrichment in LREE relative to HREE. The data demonstrates a systematic stratigraphic variation in major and trace elements compositions of liquidus EGM in the Eudialyte Complex, the latest and uppermost part of Lovozero. The distribution of elements follows a broadly linear trend. Despite intersample variations, the absence of abrupt changes in the trends suggests continuous crystallization and accumulation in the magma chamber. The crystallization was controlled by elemental distribution between EGM and coexisting melt during gravitational accumulation of crystals and/or mushes in a closed system. A different pattern is noted in the Ilimaussaq Complex. The elemental trends have variable steepness up the magmatic succession especially in the uppermost zones of the Complex. The differences between the two complexes are suggested to be related dynamics of the crystallization and accumulation processes in the magma chambers, such as arrival of new liquidus phases and redistributions by mush melts.

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Effect of Compositional Variation on the Microstructural Evolution and the Castability of Al–Mg–Si Ternary Alloys

Metallurgical and Materials Transactions A ◽

10.1007/s11661-021-06306-5 ◽

2021 ◽

Author(s):

Abdul Wahid Shah ◽

Seong-Ho Ha ◽

Bong-Hwan Kim ◽

Young-Ok Yoon ◽

Hyun-Kyu Lim ◽

...

Keyword(s):

Microstructural Evolution ◽

Ternary Alloys ◽

Compositional Variation

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Geochemistry of Sphalerite from the Permian Volcanic-Hosted Massive Sulphide (VHMS) Deposits in the Tasik Chini Area, Peninsular Malaysia: Constraints for Ore Genesis

Minerals ◽

10.3390/min11070728 ◽

2021 ◽

Vol 11 (7) ◽

pp. 728

Author(s):

Mohd Basril Iswadi Basori ◽

Sarah E. Gilbert ◽

Khin Zaw ◽

Ross R. Large

Keyword(s):

Variable Temperature ◽

Mineral Chemistry ◽

Peninsular Malaysia ◽

Massive Sulphide ◽

Compositional Variation ◽

Volcanic Origin ◽

Sedimentary Deposits ◽

Depositional Processes ◽

Tasik Chini ◽

Vhms Deposits

The Bukit Botol and Bukit Ketaya deposits are two examples of volcanic-hosted massive sulphide (VHMS) deposits that occur in the Tasik Chini area, Central Belt of Peninsular Malaysia. The mineralisation is divided into subzones distinguished by spatial, mineralogical, and textural characteristics. The primary sulphide minerals include pyrite, chalcopyrite, sphalerite, and galena, with lesser amounts of Sn- and Ag-bearing minerals, with Au. However, pyrrhotite is absent from both deposits. This study presents the results of sphalerite chemistry analysed by using an electron microprobe. Two types of sphalerite are recognised: sphalerite from the Bukit Botol deposit reveals a range of <DL to 24.0 mole% FeS, whereas sphalerite from the Bukit Ketaya deposit shows a range of <DL to 3 mole% FeS. Significant variations are shown in Zn, Cu, Cd, and Ag levels. Although the sphalerite has a wide variation in composition, a discernible decreasing Fe trend is exhibited from the stringer zone towards massive sulphide. This compositional variation in sphalerites may in part reflect variable temperature and activity of sulphur in the hydrothermal fluids during ore formation. Alternatively, the bimodal composition variations suggest that mineral chemistry relates to contrasting depositional processes. The Zn/Cd ratios for sphalerite from both these deposits are similar to those exhibited by volcano−sedimentary deposits with a volcanic origin. Therefore, the consistently low Cd concentrations and moderate to high Zn/Cd ratios suggest mixing of seawater and minor magmatic fluids controlling the chemistry of sphalerite at both deposits during their formation.

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Bacterial influence on the formation of hematite: implications for Martian dormant life

International Journal of Astrobiology ◽

10.1017/s1473550421000124 ◽

2021 ◽

pp. 1-15

Author(s):

Sudeera Wickramarathna ◽

Rohana Chandrajith ◽

Atula Senaratne ◽

Varun Paul ◽

Padmanava Dash ◽

...

Keyword(s):

Inductively Coupled Plasma ◽

Soil Layer ◽

Soil Samples ◽

Mineral Weathering ◽

Compositional Variation ◽

Rrna Gene ◽

Potential Candidate ◽

Metabolic Processes ◽

Extraterrestrial Life ◽

X Ray

Abstract Previous exploration missions have revealed Mars as a potential candidate for the existence of extraterrestrial life. If life could have existed beneath the Martian subsurface, biosignatures would have been preserved in iron-rich minerals. Prior investigations of terrestrial biosignatures and metabolic processes of geological analogues would be beneficial for identifying past metabolic processes on Mars, particularly morphological and chemical signatures indicative of past life, where biological components could potentially be denatured following continued exposure to extreme conditions. The objective of the research was to find potential implications for Martian subsurface life by characterizing morphological, mineralogical and microbial signatures of hematite deposits, both hematite rock and related soil samples, collected from Highland Complex of Sri Lanka. Rock samples examined through scanning electron microscopy-energy dispersive X-ray (SEM-EDX) spectroscopy. Analysis showed globular and spherical growth layers nucleated by bacteria. EDX results showed a higher iron to oxygen ratio in nuclei colonies compared to growth layers, which indicated a compositional variation due to microbial interaction. X-ray diffraction analysis of the hematite samples revealed variations in chemical composition along the vertical soil profile, with the top surface soil layer being particularly enriched with Fe2O3, suggesting internal dissolution of hematite through weathering. Furthermore, inductively coupled plasma-mass spectrometry analyses carried out on both rock and soil samples showed a possible indication of microbially induced mineral-weathering, particularly release of trapped trace metals in the parent rock. Microbial diversity analysis using 16S rRNA gene sequencing revealed that the rock sample was dominated by Actinobacteria and Proteobacteria, specifically, members of iron-metabolizing bacterial genera, including Mycobacterium, Arthrobacter, Amycolatopsis, Nocardia and Pedomicrobium. These results suggest that morphological and biogeochemical clues derived from studying the role of bacterial activity in hematite weathering and precipitation processes can be implemented as potential comparative tools to interpret similar processes that could have occurred on early Mars.

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