Sr2+/Ca2+ and 44Ca/40Ca fractionation during inorganic calcite formation: III. Impact of salinity/ionic strength

In order to apply Sr/Ca and 44Ca/40Ca fractionation during calcium carbonate (CaCO3) formation as a proxy to reconstruct paleo-environments, it is essential to evaluate the impact of various environmental factors. In this study, a CO2 diffusion technique was used to crystallize inorganic calcite from aqueous solutions at different ionic strength/salinity by the addition of NaCl at 25 °C. Results show that the discrimination of Sr2+ versus Ca2+ during calcite formation is mainly controlled by precipitation rate (R in μmol/m2/h) and is weakly influenced by ionic strength/salinity. In analogy to Sr incorporation, 44Ca/40Ca fractionation during precipitation of calcite is weakly influenced by ionic strength/salinity too. At 25 °C the calcium isotope fractionation between calcite and aqueous calcium ions (Δ44/40Cacalcite-aq = δ44/40Cacalcite − δ44/40Caaq) correlates inversely to log R values for all experiments. In addition, an inverse relationship between Δ44/40Cacalcite-aq and log DSr, which is independent of temperature, precipitation rate, and aqueous (Sr/Ca)aq ratio, is not affected by ionic strength/salinity either. Considering the log DSr and Δ44/40Cacalcite-aq relationship, Sr/Ca and δ44/40Cacalcite values of precipitated calcite can be used as an excellent multi-proxy approach to reconstruct environmental conditions (e.g., temperature, precipitation rate) of calcite growth and diagenetic alteration

Towards a comprehensive analysis of agricultural land systems: What can we see with publicly available datasets in the EU and US?

Understanding agricultural land systems is paramount to preparing for future transitions under climate change. A first step in moving towards a systematic, multi-context comparison of agricultural land systems is an assessment of data availability and commensurability. We compare publicly available and publicly curated data describing agricultural land systems—those devoted to the production of food, fuel, and fiber—to map analytical potential for comparative research in the United States (US) and European Union (EU). We discuss how political priorities shape what we can(not) see in each region and articulate future data needs to support cross-context understanding of agricultural land systems dynamics. This comprehensive understanding of how and why agricultural land systems change is imperative to promoting sustainable, resilient, and just agriculture futures

Weichselzeitliche Kryocalcite als Hinweise für Eisseen in der Hüttenbläserschachthöhle (Iserlohn/NRW)

C/O-stable isotope composition (VPDB) of speleothems from the Makkaronihalle of the Hüttenbläserschacht Cave in Iserlohn shows a clear separation between glacial and interglacial calcites. In contrast to normal speleothems (stalagmites, excentriques, crystals in cave ponds, draperies; δ18O: –4.0 to –6.1 ‰, δ13C: –4.9 to –10.9 ‰), rhombohedral crystal sinter and spherulitic speleoparticles are characterised by lower δ18O (–8.9 to –17.9 ‰) and higher δ13C values (+0.7 to –6.1 ‰). This suggests that these speleogenetic particles were formed in slowly freezing waterpools on ice during the transition from a stadial to an interstadial phase. Precise 230Th/U-dating shows younger Weichselian ages of 28.6 to 33.0 ka for these speleogenetic particles from north-west Germany. These formation periods indicate freezing conditions overlain by 34 m of hostrock and provide the minimum depth of permafrost penetration for the younger Weichselian in the area of the northern Sauerland (north-west Germany).researc

Creating Conditions for Harnessing the Potential of Transitions to Agroecology in Europe and Requirements for Policy

Food systems require reorientation to take greater account of interactions with the environment, economy, health and society. Transitions to agroecological farming practices and systems can connect policy areas and realise environmental, economic and social aims. These transitions provide a lens for reviewing policy, practice and behaviours of actors in farming systems and value chains, identification of barriers to uptake, and policy areas to which they contribute or where there are gaps. Developing social and human capital, and governance structures that enable transitions to agroecology are key to their prospects of success. Education and life-long learning are key to developing the knowledge and skills of younger generations of land managers and other actors in value chains, throughout their careers. The outcome sought is for a shared understanding of the benefits of agroecological practices and systems, creating opportunities to rebalance policies towards delivering climate neutrality, reversing biodiversity loss, and enhancing rights of citizens. To realise those opportunities policies and strategies should be coherent across territorial and systems levels, and tailored to place, system, people, and stages of transitions. Overall, they should be designed to ensure all citizens are beneficiaries of transitions to agroecological farming systems, over the long term, and that no-one or place is disadvantaged by the processes of change or the outcome intended.</p

Creating Conditions for Harnessing the Potential of Transitions to Agroecology in Europe and Requirements for Policy

Food systems require reorientation to take greater account of interactions with the environment, economy, health and society. Transitions to agroecological farming practices and systems can connect policy areas and realise environmental, economic and social aims. These transitions provide a lens for reviewing policy, practice and behaviours of actors in farming systems and value chains, identification of barriers to uptake, and policy areas to which they contribute or where there are gaps. Developing social and human capital, and governance structures that enable transitions to agroecology are key to their prospects of success. Education and life-long learning are key to developing the knowledge and skills of younger generations of land managers and other actors in value chains, throughout their careers. The outcome sought is for a shared understanding of the benefits of agroecological practices and systems, creating opportunities to rebalance policies towards delivering climate neutrality, reversing biodiversity loss, and enhancing rights of citizens. To realise those opportunities policies and strategies should be coherent across territorial and systems levels, and tailored to place, system, people, and stages of transitions. Overall, they should be designed to ensure all citizens are beneficiaries of transitions to agroecological farming systems, over the long term, and that no-one or place is disadvantaged by the processes of change or the outcome intended

An original phylogenetic approach identified mitochondrial haplogroup T1a1 as inversely associated with breast cancer risk in BRCA2 mutation carriers

Introduction: Individuals carrying pathogenic mutations in the BRCA1 and BRCA2 genes have a high lifetime risk of breast cancer. BRCA1 and BRCA2 are involved in DNA double-strand break repair, DNA alterations that can be caused by exposure to reactive oxygen species, a main source of which are mitochondria. Mitochondrial genome variations affect electron transport chain efficiency and reactive oxygen species production. Individuals with different mitochondrial haplogroups differ in their metabolism and sensitivity to oxidative stress. Variability in mitochondrial genetic background can alter reactive oxygen species production, leading to cancer risk. In the present study, we tested the hypothesis that mitochondrial haplogroups modify breast cancer risk in BRCA1/2 mutation carriers. Methods: We genotyped 22,214 (11,421 affected, 10,793 unaffected) mutation carriers belonging to the Consortium of Investigators of Modifiers of BRCA1/2 for 129 mitochondrial polymorphisms using the iCOGS array. Haplogroup inference and association detection were performed using a phylogenetic approach. ALTree was applied to explore the reference mitochondrial evolutionary tree and detect subclades enriched in affected or unaffected individuals. Results: We discovered that subclade T1a1 was depleted in affected BRCA2 mutation carriers compared with the rest of clade T (hazard ratio (HR) = 0.55; 95% confidence interval (CI), 0.34 to 0.88; P = 0.01). Compared with the most frequent haplogroup in the general population (that is, H and T clades), the T1a1 haplogroup has a HR of 0.62 (95% CI, 0.40 to 0.95; P = 0.03). We also identified three potential susceptibility loci, including G13708A/rs28359178, which has demonstrated an inverse association with familial breast cancer risk. Conclusions: This study illustrates how original approaches such as the phylogeny-based method we used can empower classical molecular epidemiological studies aimed at identifying association or risk modification effects.Peer reviewe

The Influence of Karst Aquifer Mineralogy and Geochemistry on Groundwater Characteristics: West Bank, Palestine

This work reports, for the first time, the mineralogical and geochemical characteristics of karst aquifers in the Central West Bank (CWB) catchment in Palestine. It provides an integrated study approach by correlating the geochemistry of the lithology and hydrochemical data of groundwater samples. Mineralogical analysis showed that all of the samples were dominantly composed of either calcite CaCO3 (5&#8315;100 wt. %) or dolomite CaMg(CO3)2 (4&#8315;100 wt. %), with minor amounts of quartz and feldspar, which is supported by the inorganic carbon content (9&#8315;13 wt. %) and hydrochemical composition of the spring water samples. The whole-rock geochemical data indicated that the samples have low contents of trace elements and transition metals. In contrast, the concentrations of alkaline earth elements (Mg, Ca, Sr, Ba) and Mn were high in the rock and groundwater samples. Generally, the trace elements of rock samples with concentrations &gt;10 ppm included Sr (17&#8315;330 ppm), Mn (17&#8315;367 ppm), Ba (2&#8315;32 ppm), W (5&#8315;37 ppm), Cr (3&#8315;23 ppm), Zn (1.7&#8315;28 ppm), V (4&#8315;23 ppm), and Zr (1&#8315;22 ppm), while the concentrations of all the other trace elements was below 10 ppm. Ionic ratios and hierarchical cluster analysis (HCA) suggested that the chemical evolution of groundwater was mainly related to the geogenic (rock&#8315;water) interaction in the study area. This is clear in the alkaline earth elements (Mg, Ca, Sr, Ba) ratios, especially regarding the Sr values. The calcite rock samples had higher Sr (mean 160 ppm, n = 11) than those of the dolomite rocks (mean 76 ppm, n = 9)

Determination of Methanogenic Pathways through Carbon Isotope (δ¹³C) Analysis for the Two-Stage Anaerobic Digestion of High-Solids Substrates

This study used carbon isotope (δ¹³C)-based calculations to quantify the specific methanogenic pathways in a two-stage experimental biogas plant composed of three thermophilic leach bed reactors (51–56 °C) followed by a mesophilic (36.5 °C) anaerobic filter. Despite the continuous dominance of the acetoclastic <i>Methanosaeta</i> in the anaerobic filter, the methane (CH₄) fraction derived from carbon dioxide reduction (CO₂), <i>f</i>_mc, varied significantly over the investigation period of 200 days. At organic loading rates (OLRs) below 6.0 gCOD L^–1d^–1, the average <i>f</i>_mc value was 33%, whereas at higher OLRs, with a maximum level of 17.0 gCOD L^–1d^–1, the <i>f</i>_mc values reached 47%. The experiments allowed for a clear differentiation of the isotope fractionation related to the formation and consumption of acetate in both stages of the plant. Our data indicate constant carbon isotope fractionation for acetate formation at different OLRs within the thermophilic leach bed reactors as well as a negligible contribution of homoacetogenesis. These results present the first quantification of methanogenic pathway (<i>f</i>_mc values) dynamics for a continually operated mesophilic bioreactor and highlight the enormous potential of δ¹³C analysis for a more comprehensive understanding of the anaerobic degradation processes in CH₄-producing biogas plants

Assessing farming systems in transition to agroecology

International audienc