Iron-Copper-Zinc Isotopic Compositions of Andesites from the Kueishantao Hydrothermal Field off Northeastern Taiwan

The studies of iron (Fe), copper (Cu), and zinc (Zn) isotopic compositions in seafloor andesites are helpful in understanding the metal stable isotope fractionation during magma evolution. Here, the Fe, Cu, and Zn isotopic compositions of andesites from the Kueishantao hydrothermal field (KHF) off northeastern Taiwan, west Pacific, have been studied. The majority of δ56Fe values (+0.02‰ to +0.11‰) in the KHF andesites are consistent with those of MORBs (mid-ocean ridge basalts). This suggests that the Fe in the KHF andesites is mainly from a MORB-type mantle. The Fe-Cu-Zn isotopic compositions (δ56Fe +0.22‰, δ65Cu +0.16‰ to +0.64‰, and δ66Zn +0.29‰ to +0.71‰) of the KHF andesites, which are significantly different from those of the MORBs and the continental crust (CC), have a relatively wide range of Cu and Zn isotopic compositions. This is most likely to be a result of the entrainment of the sedimentary carbonate-derived components into an andesitic magma. The recycled altered rocks (higher δ56Fe, lower δ66Zn) could preferentially incorporate isotopically light Fe and heavy Zn into the magma, resulting in relative enrichment of the lighter Fe and heavier Zn isotopes in the andesites. The majority of the δ56Fe values in the KHF andesites are higher than those of the sediments and the local CC and lower than those of the subducted altered rocks, while the reverse is true for δ66Zn, suggesting that the subseafloor sediments and CC materials (lower δ56Fe, higher δ66Zn) contaminating the rising andesitic magma could preferentially incorporate isotopically heavy Fe and light Zn into the magma, resulting in relative enrichment of the heavier Fe and lighter Zn isotopes in the andesites. Thus, the characteristics of the Fe and Zn isotopes in back-arc and island-arc volcanic rocks may also be influenced by the CC and plate subduction components.

Soil pollution indexes through the assessment of a compositional baseline - the Langreo case study, Spain

<p>When considering complex scenarios, such as in environmental characterization, where a multiset of attributes must be considered, a dimensional reduction of the problem is mandatory for a clear apprehension of the reality. Maps, broadly mentioned in the literature, are great for spatial pattern visualization of pollutant’s concentration distribution, or to assign areas of contamination enrichment, either if natural or triggered by anthropogenic activities. In the present study, a set of 15 Potentially Toxic Elements - PTEs - (As, Ba, Cd, Co, Cr, Cu, Hg, Mo, Ni, Pb, Sb, Se, Tl, V, and Zn) were analyzed in soils gathered in the Langreo area (80 Km2) —Asturias, Spain— and used (a) to analyze how high concentrations in PTEs are spatially distributed and (b) to explore dissemination trends and the definition of clusters of relative enrichment. To quantify soil pollution, it is important to understand what is meant by pollution-free soil. Often, this background, or pollution baseline, is undefined or only partially known. Given that the concentration of chemical elements is compositional, as the attributes vary together, our approach is based on compositional principles. Finding a balance of pollutant (numerator) over non-pollutant (denominator) elements, aiming sparsity and simplicity as properties, is the key issue for the construction of a Compositional Pollution Index, and two approaches have been explored: (1) taking into account the whole observed composition, and (2) taking into account only a subcomposition, based on expert knowledge, in which the reported elements are: Na, K, Ca, Al, Mg, Fe, Cu, Pb, Zn, As, Sb, Hg. In all tested cases, Sb, Pb, and Hg appear in the numerator of the balance, and K, Al, and Zn in the denominator. A conclusion could be that the overall pollution in the Langreo region is dominated by the content of Sb, Pb, and Hg, relative to the content of K, Al, and Zn. Finally, both indexes went through a stochastic sequential Gaussian simulation. The spatial characterization allowed a broad discussion about not only the concentrations’ spatial distribution and associated uncertainty, but also a better understanding of the possibility of trends of relative enrichment and insight in PTEs fate.</p>

Spatial Distribution and Relative Enrichment of Some Upper-Group Trace Elements in Rhizosphere of Highly Anthropized and Rapidly Developing Tropical Environment

Most upper-group (Groups 13-17) trace elements are toxic including those already confirmed as micronutrients considering the very thin margin between their adequacy and toxicity in the biosphere. The concentrations, distribution and relative enrichment were studied of some of these elements in 0-50-cm soil layer at Ikwo in southeastern Nigeria representing largely disturbed and rapidly evolving ecosystems of the humid tropical region. Samples was from the north (N), south (S), east (E) and west (W) zones with pronounced mining and agricultural activities, including a reference zone at the centre (F). The samples were taken from fallow lands in the dry season. The concentrations of the trace elements were determined using Inductively Coupled Plasma Atomic Emission Spectroscopy. Enrichment factor was calculated as the ratio of each element to that of Fe (as a reference element) in the soil. The elements had their highest concentrations in F-zone and lowest in N-zone, with top-bottom ranges as 21.00-10.75, 1.83-0.93, 10.90-5.58, 4.05-2.05, 4.97-2.54, 2.20-1.12, 17.75-9.09, 26.74-13.69, 4.41-2.26, and 1.89-0.96 mg kg–1 for Se, As, B, Al, Si, S, Sn, Sb, I and Br, respectively. Thus mining and agricultural activities, rather than leading to the build-up of these elements, tend to contribute towards reducing their levels in the rhizosphere. Enrichment factors indicated moderate-to-insignificant levels of the majority of the elements in the soils. Generally, the elements showed similar distribution and enrichment patterns across the five zones. These results suggest that, at their current modes and intensities in the humid tropics, mining and agricultural activities apparently may not pose any ecological hazards due to these trace elements.

Conjugated enrichments in arsenic and antimony in marine deposits used as paleoenvironmental proxies: preliminary results

Two redox-sensitive metalloids, arsenic (As) and antimony (Sb), are examined here to determine what can be their help in the deciphering of past depositional conditions. The enrichment factors of the two elements are compared for a set of geological formations and marine deposits covering a relatively wide range of paleoenvironmental settings, from oxic to euxinic conditions. This work confirms that As and Sb are not robust paleoredox proxies but examining their relative enrichment may be useful. These preliminary results indicate that a co-enrichment of both elements with Sb being more enriched than As could be the mark of the so-called particulate shuttle effect. Notably, Sb would be more sensitive to Mn-shuttling than As. If confirmed, this trend could be used to further identify the cause of As-enrichment in marine sediments impacted by cold seepage fluids.

Differential Gene Set Enrichment Analysis: a statistical approach to quantify the relative enrichment of two gene sets

Motivation Gene Set Enrichment Analysis (GSEA) is an algorithm widely used to identify statistically enriched gene sets in transcriptomic data. However, GSEA cannot examine the enrichment of two gene sets or pathways relative to one another. Here we present Differential Gene Set Enrichment Analysis (DGSEA), an adaptation of GSEA that quantifies the relative enrichment of two gene sets. Results After validating the method using synthetic data, we demonstrate that DGSEA accurately captures the hypoxia-induced coordinated upregulation of glycolysis and downregulation of oxidative phosphorylation. We also show that DGSEA is more predictive than GSEA of the metabolic state of cancer cell lines, including lactate secretion and intracellular concentrations of lactate and AMP. Finally, we demonstrate the application of DGSEA to generate hypotheses about differential metabolic pathway activity in cellular senescence. Together, these data demonstrate that DGSEA is a novel tool to examine the relative enrichment of gene sets in transcriptomic data. Availability and implementation DGSEA software and tutorials are available at https://jamesjoly.github.io/DGSEA/. Supplementary information Supplementary data are available at Bioinformatics online.

Differential Gene Set Enrichment Analysis: A statistical approach to quantify the relative enrichment of two gene sets

Gene Set Enrichment Analysis (GSEA) is an algorithm widely used to identify statistically enriched gene sets in transcriptomic data. However, to our knowledge, there exists no method for examining the enrichment of two gene sets relative to one another. Here, we present Differential Gene Set Enrichment Analysis (DGSEA), an adaptation of GSEA that assesses the relative enrichment of two gene sets. Using the metabolic pathways glycolysis and oxidative phosphorylation as an example, we demonstrate that DGSEA accurately captures the hypoxia-induced shift towards glycolysis. We also show that DGSEA is more predictive than GSEA of the metabolic state of cancer cell lines, including lactate secretion and intracellular concentrations of lactate and AMP. Furthermore, we demonstrate that DGSEA identifies novel metabolic dependencies not found by GSEA in cancer cell lines. Together, these data demonstrate that DGSEA is a novel tool to examine the relative enrichment of two gene sets.

INTERPRETATION OF RADIOMETRIC RATIOS AND MAGNETIC ANOMALIES FROM MORRO FEIO ULTRAMAFIC COMPLEX, CENTRAL-WESTERN BRAZIL

ABSTRACTThis study was performed to identify magnetic structures in depth and radiometric responses within and around Morro Feio Ultramafic Complex (MFUC) from the airborne geophysical (gamma–ray spectrometry and magnetic) data. Using processing techniques and profiles analysis, we have found eight gamma–ray spectrometry signatures and twenty–seven magnetic anomalies. The radiometric signatures are basically characterized by a K and eU relative enrichment in detriment eTh, with two of these signatures also characterized by K relative enrichment in detriment eU. Based on published works, we have interpreted the radiometric responses may be from serpentinite and possible areas with hydrothermal alterations. Regarding the magnetic anomalies, we concluded that the shallowest may be the magnetic responses of dikes, contact zones and other structures, while the deepest have sources with more complex geometries and are concentrated in central–western of MFUC, where the participation of Pt is larger. In this aspect, our results reinforce the arguments favorable to existence of Pt, Cr and Ni primary sources in depth.Keywords: mineral research, airborne geophysical, serpentinites, hydrothermal alteration.RESUMOEste estudo foi realizado com o objetivo de identificar estruturas magnéticas em profundidade e respostas radiométricas dentro e no entorno do Complexo Ultramáfico de Morro Feio (CUMF) a partir de dados aerogeofísicos (gamaespectrometria e magnetometria aérea). Utilizando técnicas de processamento e análise de perfis, encontramos oito assinaturas gamaespectrométrica e vinte e sete anomalias magnéticas. As assinaturas radiométricas caracterizam–se basicamente por um enriquecimento relativo de K e eU em detrimento eTh, com duas dessas assinaturas também sendo caracterizadas pelo enriquecimento relativo de K em detrimento eU. Com base em trabalhos publicados, interpretamos que as respostas radiométricas podem ser em virtude do serpentinito e possíveis áreas com alterações hidrotermais. Com relação às anomalias magnéticas, concluímos que as mais rasas podem ser as respostas magnéticas de diques, zonas de contato e outras estruturas, enquanto que as mais profundas possuem fontes com geometrias mais complexas e se concentram no centro–oeste do CUMF, onde a participação de Pt é maior. Neste aspecto, nossos resultados reforçam os argumentos favoráveis a existência de fontes primárias de Pt, Cr e Ni em profundidade.Palavras-chave: pesquisa mineral, aerogeofísica, serpentinitos, alteração hidrotermal.

Volcanism and geochemistry of soil and vegetation cover of Kamchatka. Communication 1. Geochemical features of volcanic surface ashes

Common geochemical features of volcanic near-surface ashes of Kamchatka (ashes located under the surface organogenic soil horizons) are their depletion by most chemical elements in comparison with average indicators for volcanic rocks of corresponding composition and relative enrichment of a limited range of elements, mainly typomorphic for main rocks (P, Mg V, Cr, Cu, Zn, Zr, Sb). Against the background of small variations in the contents of chemical elements in the ashes of different areas of the peninsula, the range of their priority elements is determined by their petrochemical composition. The active activity of the Northern group of volcanoes of Kamchatka causes a relatively high content of mobile forms of elements in the near-surface ashes of the Northern province in comparison with the ashes of the southern part of the peninsula.

Volcanism and geochemistry of soil and vegetation cover of Kamchatka. Communication 1. Geochemical features of volcanic surface ashes

Common geochemical features of volcanic near-surface ashes of Kamchatka (ashes located under the surface organogenic soil horizons) are their depletion by most chemical elements in comparison with average indicators for volcanic rocks of corresponding composition and relative enrichment of a limited range of elements, mainly typomorphic for main rocks (P, Mg V, Cr, Cu, Zn, Zr, Sb). Against the background of small variations in the contents of chemical elements in the ashes of different areas of the peninsula, the range of their priority elements is determined by their petrochemical composition. The active activity of the Northern group of volcanoes of Kamchatka causes a relatively high content of mobile forms of elements in the near-surface ashes of the Northern province in comparison with the ashes of the southern part of the peninsula.