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A comprehensive study was conducted in the Cuatro Ciénegas Basin (CCB) in Coahuila, Mexico, which is known for its diversity of microorganisms and unique physicochemical properties. The study focused on the "Archaean Domes" (AD) site in the CCB, which is characterized by an abundance of hypersaline, nonlithifying microbial mats. In AD, we analyzed the small domes and circular structures using metagenome assembly genomes (MAGs) with the aim of expanding our understanding of the prokaryotic tree of life by uncovering previously unreported lineages, as well as analyzing the diversity of bacteria and archaea in the CCB. A total of 325 MAGs were identified, including 48 Archaea and 277 Bacteria. Remarkably, 22 archaea and 104 bacteria could not be classified even at the genus level, highlighting the remarkable novel diversity of the CCB. Besides, AD site exhibited significant diversity at the phylum level, with Proteobacteria being the most abundant, followed by Desulfobacteria, Spirochaetes, Bacteroidetes, Nanoarchaeota, Halobacteriota, Cyanobacteria, Planctomycetota, Verrucomicrobiota, Actinomycetes and Chloroflexi. In Archaea, the monophyletic groups of MAGs belonged to the Archaeoglobi, Aenigmarchaeota, Candidate Nanoarchaeota, and Halobacteriota. Among Bacteria, monophyletic groups were also identified, including Spirochaetes, Proteobacteria, Planctomycetes, Actinobacteria, Verrucomicrobia, Bacteroidetes, Candidate Bipolaricaulota, Desulfobacteria, and Cyanobacteria. These monophyletic groups were possibly influenced by geographic isolation, as well as the extreme and fluctuating environmental conditions in the pond AD, such as stoichiometric imbalance of C:N:P of 122:42:1, fluctuating pH (5-9.8) and high salinity (5.28% to saturation). [ABSTRACT FROM AUTHOR]

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The ordinary Portland cement (OPC) component of concrete is the highest contributor to concrete's cost and carbon footprint. Historically, code-writing organizations have required a high volume of paste in concrete mixtures by imposing minimum limits on the OPC content for a given application. However, high paste contents can result in dimensional instability, higher costs, higher carbon footprints, and lower durability. Minimizing the OPC content in concrete can provide economic, durability, and sustainability benefits. This study hypothesizes that the amount of OPC required to achieve some required fresh and hardened characteristics is highly dependent on the aggregate characteristics, supplementary cementing material (SCM) characteristics, and proportions of these. Given this, this research proposes using the amount of voids in the aggregate system (AV), or more specifically the paste volume-to-aggregate void ratio (PV/AV); SCM reactivity; and the SCM replacement level as key parameters to proportion concrete mixtures with minimum OPC contents to meet sustainability, economic, and resilience (SER) requirements. A new mixture proportioning procedure, referred to here as the SER proportioning method, is developed in this study based on assessing AV and identifying an optimal PV/AV that satisfies the required concrete characteristics. The results show that implementing the SER mixture proportioning method and including SCMs, or more specifically off-spec fly ashes (OFAs), can lead to significant reductions in the paste content and associated reductions in the cost and embodied carbon footprint of concrete. [ABSTRACT FROM AUTHOR]

A little over ten years ago, the anthropological academy of the global North baptized with the name "multispecies" a mode of study and writing that de-centers the human and that, in research, pays attention to the socio-cultural and affective force of multiple bodies and materialities. However, these kinds of multiple and diverse relationalities have been a constitutive part of many peoples in the global South, subalternized peoples whose historical, situated, and embodied experience account for epistemologies and ways of life obliterated by the modern-racist-colonial system. In other words, these peoples have been able to recognize and name our fragile and precarious condition, which requires more-than-human beings to become possible, in intimate affectation and interdependence, and in collaborative survival; so "multispecies" is just one more word, among others, to refer to the intricate space of relationships that give shape and content to what we call "society", "culture", and "nature". In the time of the Anthropocene, this era of life annihilation driven by rapacious capitalism-speciesism, it is necessary to acknowledge our vital connections with multiple human, animal, plant, mineral, and other kinds of bodies - and their particular ways of being named - in order to propose politics of collaboration and interdependence from which it might be possible to imagine other, more-thanhuman futures; futures that, in fact, might already be imagined and contested right now, from and in the South. So, the objective of this anthropological essay-manifesto is, drawing from Robin Wall Kimmerer, to think about "multispecies grammars of the animated" as an alternative to these times of ruin and necessary creativity to converse with other forms of life and non-life and to reorient ourselves from other epistemologies situated in the margins and embracing that other world that walks with us towards plural futures beyond the Anthropo-capitalocene. [ABSTRACT FROM AUTHOR]

The variability and drivers of carbon and water fluxes and their relationship to ecosystem water use efficiency (WUE) in natural ecosystems of southern South America are still poorly understood. For eight years (2015–2022), we measured water and carbon fluxes using eddy covariance towers in a temperate rainforest and a peatland in southern Chile. Different expressions for ecosystem WUE were derived from estimates of gross primary productivity (GPP) and evapotranspiration (ET), which was further partitioned into evaporation (E) and transpiration (T). We then used the correlation between detrended time series and structural equation modeling to identify the main environmental drivers of WUE, GPP, ET, E and T. The results showed that WUE is low in both ecosystems, and likely explained by the high annual precipitation in this region (∼2100 mm). Only expressions of WUE that included atmospheric water demand showed seasonal variation. Variations in WUE were related more to changes in ET than to changes in GPP, while T remained relatively stable accounting for around 47 % of ET for most of the study period. For both ecosystems, E increased with higher global radiation, higher surface conductance and when the water table was closer to the surface. Higher values for E were also found with increased wind speeds in the forest and higher air temperatures in the peatland. The absence of a close relationship between ET and GPP is likely related to the dominance of plant species that either do not have stomata (i.e., mosses in the peatland or epiphytes in the forest) or have poor stomatal control (i.e., anisohydric tree species in the forest). The observed increase in potential ET in the last two decades and the projected drought in this region suggests that WUE could increase in these ecosystems, particularly in the forest, where stomatal control may be more significant. [ABSTRACT FROM AUTHOR]

Fly ashes that do not meet the ASTM C618 specifications are considered "off-spec" and are not used as supplementary cementitious materials (SCMs). In this research, four off-spec fly ashes (OFAs) were sourced from different parts of the United States and the characteristics of these OFA concretes were measured to compare their performance with that of the mixtures containing 0% OFA. The first objective of this study is to assess the influence of OFA reactivity and replacement levels on concrete characteristics. The second objective is to assess the influence of constituent material characteristics such as shape and size of coarse aggregate, fineness modulus of fine aggregate, and cementitious content of the concrete mixture on the fresh and hardened characteristics of concretes containing OFAs. Results indicate that at sufficient degrees of reactivity and replacement levels, OFAs can provide characteristics comparable to that of conventional ordinary portland cement (OPC) concrete while improving the consistency of the concrete. Findings from sensitivity analysis reveal that the degree of reactivity (DoR) of the OFA has a high influence on the hardened characteristics of concrete. Finally, the life cycle assessment of concrete mixtures containing OFAs indicate that greenhouse gas emissions can be reduced up to 45% when compared to conventional mixtures. [ABSTRACT FROM AUTHOR]