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A prime opportunity for cities and towns is the potential to utilize existing local urban landscape qualities as sources for the enhancement of landscape connections and places. The application of this opportunity is often a key fac¬tor in the preservation of livability and identity in their respective urban loca¬tions. The application of potential bottom-up enhancements is a prime focus for many communities interested in the role and use of existing inductive bot¬tom-up context qualities as priorities for enhanced livability and community identity. Bottom-up responses to urban context enhancements are a focus in this discussion, with references to the three themes of the text, including time, resources, and livability. The discussion recognizes the role that bottom-up strategies play in the enhancement of connections and places, emphasizing the opportunity for the use of bottom-up planning and design strategies in urban landscapes. However, the broader issue is the need for equitable access to urban landscape enhancements within underrepresented urban locations.
Within the past decade, bottom-up preferences and strategies have contin¬ued to evolve as resources in line with the need to provide equitable access to urban landscape qualities. Urban locations with historical significance, unique scale, materials, and efficient connection are examples of bottom-up opportunities for the preservation of identity and livability in urban contexts that are sustaining enhancements in response to current and future climate change. The significant difference concerns what communities have so far been able to produce in terms of livable and equitable landscape contexts and what communities may be able to accomplish in the future. Both rest on being able to endure current and future climate change and maintain via¬ble livability strategies.
Plastic chemicals are numerous and ubiquitous in modern life and pose significant risks to human health. Observational epidemiological studies have been instrumental in identifying consistent and statistically significant associations between exposure to certain chemicals and adverse health outcomes. However, these studies often fail to establish causality due to the complexity of real-world chemical mixtures, confounding factors, reverse causation, and study designs that lack measures reflecting underlying genetic and cellular mechanisms indicating causal pathways to harm. Addressing these limitations requires moving beyond traditional ‘black-box’ epidemiology, which mainly focuses on the strength of associations. We propose adopting hybrid epidemiological methodologies that incorporate genetic susceptibility and molecular mechanisms to uncover biological pathways, combined with machine learning and statistical analysis of chemical mixtures, to strengthen the causal evidence linking exposure to harm. By integrating observational multi-omics data with experimental and mechanistic models, hybrid epidemiology offers a transformative path to improve causal evidence and public health interventions. In addition, machine learning and statistical methods provide a more nuanced understanding of the health effects of exposures to plastic chemical mixtures, facilitating the identification of interactions within chemical mixtures and the influence of biological pathways. This paradigm shift is critical addressing the complex challenges of plastic exposure and protecting human health.
Iron oxide-apatite (IOA) deposits and the related iron oxide-copper-gold (IOCG) deposits, are major repositories of base metals (Fe, Cu). However, the genesis of IOA deposits remains a topic of debate, with both magmatic and hydrothermal models. Close parallels exist between IOA deposits and some skarns, which exhibit sodic alteration in silicic host rocks, but are unequivocally metasomatic in origin. In this study we compared the trace element composition of magnetite from IOA deposits in the Kiruna District, Sweden, with magnetite skarns from the Turgai district, Kazakhstan. Comparison with published discrimination diagrams for deposit types shows poor correspondence with defined fields. The two districts correspond closely in terms of Sn and Ga contents, with close correspondence to previous analyses of porphyry and skarn deposits. When estimates of temperature (T) from Mg in magnetite are considered Sn and Ga show little correlation with T, whereas Ni increases and Mn decreases with decreasing T. Rare earth element distribution patterns correspond to local igneous rocks, albeit at lower absolute concentration. Tin and Ga, as high valence ions in tetrahedral sites in magnetite are potentially more resistant to re-equilibration and preserve a high temperature magmatic-hydrothermal signature comparable to Fe skarns and the early magmatic stages of some IOA deposits in the Kiruna district. Overall, these data are consistent with an early high-temperature mineralisation stage, potentially resulting from hypersaline brines or salt melts interacting with volcanic rocks (Kiruna district) or limestone and volcanic rocks (Turgai district), followed by subsequent hydrothermal magnetite mineralisation to relative low T. The high-temperature stage is better represented in the Turgai skarns compared to the Kiruna district IOA deposits. Overprint of sulfide mineralisation on magnetite results in an increase in Ni content which may be an effective tracer for IOCG mineralisation related to IOA deposits, or sulfide mineralisation in skarns, whilst metamorphism may homogenise and reduce trace element concentrations.
Characterizing the structure and composition of clay minerals on the surface of Mars is important for reconstructing past aqueous processes and environments. Data from the CheMin X-ray diffraction (XRD) instrument on the Mars Science Laboratory Curiosity rover demonstrate a ubiquitous presence of collapsed smectite (basal spacing of 10 Å) in ~3.6-billion-year-old lacustrine mudstone in Gale crater, except for expanded smectite (basal spacing of 13.5 Å) at the base of the stratigraphic section in a location called Yellowknife Bay. Hypotheses to explain expanded smectite include partial chloritization by Mg(OH)2 or solvation-shell H2O molecules associated with interlayer Mg2+. The objective of this work is to test these hypotheses by measuring partially chloritized and Mg-saturated smectite using laboratory instruments that are analogous to those on Mars rovers and orbiters. This work presents Mars-analog XRD, evolved gas analysis (EGA), and visible/shortwave-infrared (VSWIR) data from three smectite standards that were Mg-saturated and partially and fully chloritized with Mg(OH)2. Laboratory data are compared with XRD and EGA data collected from Yellowknife Bay by the Curiosity rover to examine whether the expanded smectite can be explained by partial chloritization and what this implies about the diagenetic history of Gale crater. Spectral signatures of partial chloritization by hydroxy-Mg are investigated that may allow the identification of partially chloritized smectite in Martian VSWIR reflectance spectra collected from orbit or in situ by the SuperCam instrument suite on the Mars 2020 Perseverance rover. Laboratory XRD and EGA data of partially chloritized saponite are consistent with data collected from Curiosity. The presence of partially chloritized (with Mg(OH)2) saponite in Gale crater suggests brief interactions between diagenetic alkaline Mg2+-bearing fluids and some of the mudstone exposed at Yellowknife Bay, but not in other parts of the stratigraphic section. The location of Yellowknife Bay at the base of the stratigraphic section may explain the presence of alkaline Mg2+-bearing fluids here but not in other areas of Gale crater investigated by Curiosity. Early diagenetic fluids may have had a sufficiently long residence time in a closed system to equilibrate with basaltic minerals, creating an elevated pH, whereas diagenetic environments higher in the section may have been in an open system, therefore preventing fluid pH from becoming alkaline.
The rare Pb silicate jagoite, known only from the Långban and Pajsberg Mn–Fe oxide deposits in Värmland, Sweden, is associated with a more diverse mineral assemblage than originally described: alamosite, barysilite, hyttsjöite, margarosanite, melanotekite, nasonite and yangite and other, not fully characterised Pb silicates. Primary melanotekite and barysilite, formed as skarn (together with hematite, quartz, clinopyroxene and andradite) during regional metamorphism, are prone to alteration, with Cl⁻, SiO₂, Ca2⁺ and H₂O acting as modifying agents. In the process, newly formed Pb silicates exhibit increasing Si content, reflecting a higher degree of SiO₄ polymerisation at high pH and decreasing temperatures.
A refinement of the crystal structure of jagoite from X-ray diffraction data, to R1 = 1.2% [space group P$\bar 6$2c, a = 8.53926(5) Å and c = 33.3399(2) Å], confirms previous work, and provides significantly improved structural parameters. New data were also obtained with Mössbauer spectroscopy, laser-Raman micro-spectroscopy, electron-microprobe and laser-ablation inductively coupled plasma mass spectrometry analyses. The results indicate that jagoite accommodates minor elements, notably Al at an octahedrally coordinated Fe-dominated site and Mn3⁺, Zn and Mg at four-coordinated mixed Fe–Si sites, and small amounts of Ca+Na replacing Pb. Jagoite is also enriched in Be, Sb, Bi and Br, but those elements have a limited role in its crystal chemistry. Mössbauer measurements show that Fe3⁺ is distributed over three different crystallographic sites, two 4-coordinated and one 6-coordinated, and that jagoite remains paramagnetic down to 77 K. The ideal chemical formula for jagoite should be written Pb11Fe5Si12O41Cl3 for Z = 2.
Ice crystal fabrics can exert significant rheological control on ice sheets and ice shelves, potentially softening or hardening anisotropic ice by several orders of magnitude compared to isotropic ice. We introduce an anisotropic extension of the Shallow Shelf Approximation (SSA), allowing for fabric-induced viscous anisotropy to affect the flow of ice shelves in coupled, transient simulations. We show that the viscous anisotropy of synthetic ice shelves can be parameterized using an isotropic flow enhancement factor, suggesting that existing SSA flow models could, with little effort, approximate the effect of fabric on flow. Next, we propose a new way to directly solve for SSA fabric fields using satellite-derived velocities, assuming velocities are approximately steady and that fabric evolution is dominated by lattice rotation with or without discontinuous dynamic recrystallization. We apply our method to the Ross and Pine Island ice shelves, Antarctica, suggesting that these regions might experience significant fabric-induced hardening and softening depending on the relative strength of lattice rotation and recrystallization. Our results emphasize the ice-dynamical relevance of needing to better constrain the strength of fabric processes. This calls for more widespread fabric and temperature measurements from the field, since measurements are currently too sparse for model validation.
Marine organisms account for more than half of the global biodiversity and have proven to be a rich source of pharmacologically active compounds. Turkey has an extensive coastline hosting a diverse marine ecosystem. This paper describes the phytochemical prospection based on chromatographic profiles of extracts, fractions, and sub-fractions from Turkish organisms. In addition, the samples were evaluated for their antioxidant, anticholinesterasic, and antibacterial activities. According to the chromatographic profiles, terpenes were identified in most samples, with the exception of Dictyonella incisa. Alkaloids were detected in Ascidiella aspersa, Eunicella cavolini, Halocynthia papillosa, Limaria hians, Microcosmus polymorphus, and D. incisa. The phenolic carboxylic acids were detected in all the samples, and the results for polyphenols were similar. The extract of P. clavata showed antioxidant activity in both models evaluated, whereas the remaining samples were positive only in the bioautographic assay. With regard to AChE inhibition, D. incisa fraction showed potent activity (%I ˃ 90%), while the sub- fractions were moderate (%I ˃ 45%). In the antibacterial assay, the same samples from D. incisa have shown activity against both Gram-negative and Gram-positive bacteria. On the other hand, the present study opens up avenues for future research on D. incisa by aligning alkaloids and neuroprotective effects, taking into account that inhibition of AChE is a therapeutic strategy in the treatment of Alzheimer’s disease.
The study explores the vertical stratification of microbial diversity and metabolic potential in Earth’s lower atmosphere. Using 16S rRNA sequencing data spanning the planetary boundary layer to the lower stratosphere, we conducted taxonomic profiling and metabolic pathways predictions. The aim was to elucidate microbial community dynamics and their ecological roles under diverse atmospheric conditions. Methods: 51 Publicly available datasets with 3584 samples were retrieved from repositories such as Sequencing Read Archive and European Nucleotide Archive, filtered for studies employing 16S rRNA sequencing. Quality control was performed using FastQC and Trimmomatic, followed by taxonomic classification with Qiime2 and the Silva132 database. Functional pathway predictions were derived using PICRUSt2, and statistical analyses included Kruskal-Wallis tests for diversity comparisons and Mann-Whitney U tests for pathway activity. Results: Microbial diversity decreased with altitude, with the Surface Layer exhibiting the highest Shannon diversity and the significantly decreased in Low Stratosphere. Taxonomic composition shifted along the elevation gradient, with Actinobacteria and Alphaproteobacteria predominant at lower altitudes. In contrast, Bacilli and Gammaproteobacteria became more dominant at higher elevations, though they maintained a notable presence at lower sites as well. Functional analysis revealed altitude-specific adaptations, including significant upregulation of CO2 fixation pathways in the Free Troposphere Transition Layer and secondary metabolite biosynthesis in the lower stratosphere. Discussion: These findings reveal distinct microbial metabolic profiles across atmospheric layers with varying conditions such as oxygen levels, UV radiation, and nutrient availability. While these differences may represent adaptive strategies, they could also reflect source environment characteristics or selective transport processes. The conserved metabolic pathways across altitude layers suggest functional resilience despite taxonomic divergence. These results have implications for astrobiology, providing analogs for microbial life in extraterrestrial environments like Mars or Europa. In summary, this study advances our understanding of aerobiomes’ ecological roles and their potential as models for life detection in extreme environments, bridging atmospheric microbiology with astrobiological exploration.
Five specimens of the rare alpheid shrimp Betaeus levifrons Vinogradov, 1950 were collected from the burrows of the mud-shrimp Upogebia major (De Haan, 1841) in Akkeshi and Usu Bays, along the Pacific coast of Hokkaido, Japan. As B. levifrons has been previously only reported from the Russian coast of the Sea of Japan, the Hokkaido specimens represent the first record of this species from the western Pacific coast as well as a new to the Japanese fauna. Ovigerous females of B. levifrons were recorded for the first time based on specimens. This study provides additional data on this species, including its distribution, colour variation, and DNA sequences of the mitochondrial 16S rRNA and cytochrome c oxidase subunit I barcoding regions. Lastly, we revised the available data on the symbiotic fauna of U. major.
With cities and towns in the process of developing strategies in response to current and future urban environmental and cultural issues, the potential responses, at best, would provide outcomes for positive livability in the con¬text of climate change, including livability and equitable access in future urban contexts. This focus began with the first phase of current responses to climate change generally appearing after the Paris Climate Agreement in 2015. Cities and towns continued to produce key initiatives in response to climate change and the need for equitable access, with an emphasis on climate mitigation, urban greening, walkability, and access. The results are potential planning and design approaches needed to advance the prospects of climate mitigation and equity as influences for viable livability in future urban contexts, including connections and urban landscapes. A prime chal¬lenge is the need for communities to produce resources derived from public and private entities for the current and future community adaptation to cli¬mate change mitigation. Ultimately, the potential quality of urban livability relative to climate and equity management will depend on the availability of such resources as cities respond to current and future climate issues.
Urban livability can be influenced by a range of factors, including walk¬ability. Conditions that influence walkability include connection qualities in the hierarchy of connections and places along boulevards, avenues, and local streets. The hierarchy of the streets is a common feature in most urban and suburban contexts due to the efficiency required for optimal pedestrian and vehicular function. The use of the urban grid in cities has furnished a logi¬cal pattern of urban connections in urban contexts for many centuries. The hierarchical street function continues to contribute to pedestrian experience in urban landscape contexts, with positive effects on the livability of cities and towns.
Written for undergraduate students with little or no exposure to economics, this introductory textbook offers a new perspective on environmental economics for the 21st century. It explains how economics for a sustainable world requires a new approach: accepting that the economy is intrinsically dependent on nature. Drawing on up-to-date case studies from around the globe, the book examines how economic concepts and techniques can apply to a wide range of environmental challenges while ensuring that poor and vulnerable members of society are included in progress toward sustainable development. The book also addresses current environmental policy options and innovations at the local, regional, and international levels. Chapters cover key topics such as climate change, pollution, energy, minerals, forests, land use, oceans, biodiversity, and water scarcity. Included in the book are the following pedagogical features: learning objectives, boxed examples, discussion questions, lists of further resources, and a glossary.
Quantifying snow water equivalent (SWE) with ground-penetrating radar (GPR) in a warming climate is complicated by the incidence and variability of liquid water in snow. Snow surveys conducted during the melt season serve as a valuable analog to conditions under future warming. Here, we determine the variability of wet snowpack properties (relative permittivity and density) to quantify their impact on SWE estimates using GPR. We collected spatially continuous snowpack measurements with 400 MHz GPR in 2012 and 2021 across repeat transects (∼150 km each year) along with spring and summer snow depth and density measurements from snow pits and snow cores. Snow relative permittivity values ranged from 2.06 to 2.62 in 2012 and 2.11 to 5.11 in 2021, resulting in calculated volumetric liquid water content (LWC) between 1.7% and 5.7% in 2012 and 2.1% and 16% in 2021. This variability in snow relative permittivity results in SWE uncertainties of 8% —33%, with more extreme cases reaching 13%—45%. We attribute this uncertainty to spatial and temporal variability in LWC when using GPR to estimate SWE. As snowpacks become wetter with rising atmospheric temperatures, GPR surveys should include in situ relative permittivity measurements to reduce depth and SWE interpretation uncertainties.
We present analyses of bubble number-density (BND) data from the South Pole Ice Core (SPC14) showing warming of ∼7.5°C from the Late Glacial (∼19.5 ka), then relatively stable temperatures during the Holocene (<0.5°C warming), in close agreement with results of independent paleothermometers. The BND data span from ∼160 m just below pore close-off, to ∼1200 m, where bubble loss by clathrate formation is significant. Measurements were made with standard bubble ‘thick’-section techniques and a new application of three-dimensional micro-computed tomography (CT) imagery; the nearly identical results recommend the faster, nondestructive micro-CT. The very high BND at South Pole, typically 800 and 900 bubbles cm−3, reflects the joint effects of the relatively low mean-annual temperature (−49°C) and high accumulation rate (∼7.5 cm w.e. a−1). High BND is physically linked to small grain sizes at pore close-off, which in turn helps explain the near-absence of brittle-ice behavior at the site, contributing to the high quality of the recovered core with implications for siting of future ice cores. The accumulation history, derived from δ15N-N2 firn-column thickness estimates, correlates with the temperature history but varies somewhat more than saturation vapor pressure, suggesting dynamic controls including upstream slope variability.
To elucidate the attenuation mechanism of wall-bounded turbulence due to heavy small particles, we conduct direct numerical simulations (DNS) of turbulent channel flow laden with finite-size solid particles. When particles cannot follow the swirling motions of wall-attached vortices, vortex rings are created around the particles. These particle-induced vortices lead to additional energy dissipation, reducing the turbulent energy production from the mean flow. This mechanism results in the attenuation of turbulent kinetic energy, which is more significant when the Stokes number of particles is larger or particle size is smaller under the condition that the volume fraction of particles is fixed. Moreover, we propose a method to quantitatively predict the degree of turbulence attenuation without using DNS data by estimating the additional energy dissipation rate in terms of particle properties.
This letter to the editor explores the importance of a just transition for waste pickers in the context of the global plastics treaty. It sets out ideas for just transition at the level of production reduction, replacements and substitutes, systems change and waste management.
A key challenge in advancing slushflow management is the limited record of past incidents. Identifying their starting points and enhancing the quality of slushflow documentation are important in order to improve the regional early warning and develop slushflow numerical runout models and susceptibility maps. Here we investigate three major slushflow events at Kistrandfjellet, northern Norway and quantify the differences between registered slushflows in the national rapid mass movement database and the actual events. We use unique image datasets from the events in February 2021, January 2023 and January 2024, and identify slushflow starting points and flow paths. The curvature of the starting point locations is examined to assess how local topography influences slushflow release at the field site. Our mapping reveals 25 slushflows across the three events, whereas only five were registered in the database. For the 2021 event, we found six times as many slushflows as were officially registered. Comparison of our mapped slushflows to modeled drainage pathways and FKB-Vann (the official surface water dataset of Norway), yielded an average overlap of 35%. To improve slushflow management, we recommend establishing a standardized protocol for future data collection.
A clay from Weslatiya that is widely used in Tunisian ceramic production has abundant reserves but generates significant waste, posing environmental concerns if not handled appropriately. This study explores the valorization of this local clay by incorporating ceramic waste (chamotte) and quartz sand to produce eco-friendly materials, in line with sustainability and circular economy principles. X-ray diffraction and scanning electron microscopy analyses reveal that incorporating chamotte at levels exceeding 15% by weight improves the material’s properties. The Young’s modulus of the composite increases to 80 GPa, more than 2.5 times that of the basic clay. Chamotte can replace up to 30% of quartz sand without significantly affecting densification or porosity while preserving structural integrity. This approach offers flexibility in terms of material composition, enhancing performance and promoting sustainability by reusing waste materials for high-performance ceramics in industrial applications.