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A building stone assessment of the buff sandstone masonry of the Hawick Flood Protection Scheme, Scottish Borders
Full text linkThis report details the outcomes of an investigation undertaken by the British Geological Survey (BGS) with the aim of characterising the building stones – in terms of their geological properties and origin – that feature within the masonry associated with the Hawick Flood Protection Scheme (HFPS). BGS was commissioned by Historic Environment Scotland (HES), with the agreement of Scottish Borders Council, to perform this building stone assessment in order to independently characterise and establish the origins of the buff sandstone used in the construction of the flood defence walls, and also provide technical comment on the properties of the stone(s) employed relative to those set out in the specification. Any enquiries relating to this report should be directed to HES ([email protected]), as the commissioning body
Depositional environments and Tectonic Controls on Paleocene phosphorite-rich successions in the Marbat-Traibeel Basin, Western Desert of Iraq
No full textThis study explores the depositional environments of Paleocene phosphorite-rich carbonate and siliciclastic successions along an NNE-SSW cross-section of the Marbat-Traibeel Basin, Western Desert, Iraq. This study examines over 500 thin sections from six vertical stratigraphic sections, encompassing boreholes and outcrops along a transect from the Rutbah High to the Iraqi-Jordanian border. It investigates lithofacies distribution, depositional sequences, and basin architecture through an integrated analysis of tectonic, sedimentological, biostratigraphic, and sequence stratigraphic data, providing insights into the basin's depositional history. It aims to elucidate the geological evolution of the Paleocene Akashat Formation and the Traifawi Member/Jeed Formation within the Marbat-Traibeel Basin, located on the northern margin of the southern Tethys Ocean. This region is characterized by complex interactions between shallow marine carbonate, siliciclastic, siliceous, and phosphatic lithofacies influenced by a submerged but tectonically active structural high (Rutbah High). The study identifies 26 lithofacies classified into seven associations based on lithological and sedimentological features, representing inner, middle, and outer ramp depositional environments. The phosphorite-rich carbonate succession, particularly the Upper Danian Hirri Member, indicates deposition on an open, distally steepened ramp and hosts substantial economic phosphate reserves. Syn-depositional tectonics influenced the ramp morphology and sedimentation of the phosphorite, which resulted in lateral variations in thickness and microfacies. Tectonic instability resulted in numerous depositional hiatuses (Cretaceous/Paleogene, Lower Danian - Upper Danian; Selandian – Thanetian, Upper Paleocene – Lower Eocene boundary) and eastward thinning of depositional sequences on the Rutbah High. Seven distinct Paleocene third-order depositional sequences are identified in the western part of the study area, near the Jordan-Iraq border, passing eastward to four third-order sequences, a pattern attributed to tectonic uplift on the Rutbah High. The depositional sequences are separated by boundaries characterized by vertical facies changes, including prominent Thalassinoides burrows/firmgrounds on transgressive surfaces with significant hiatuses that correlate with known eustatic sea-level falls associated with the Arabian Platform
The genome sequence of the gorse wanderer, Brachmia blandella (Fabricius, 1798) (Lepidoptera: Gelechiidae)
Full text linkWe present a genome assembly from an individual female Brachmia blandella (Gorse Wanderer, Gorse Crest; Arthropoda; Insecta; Lepidoptera; Gelechiidae). The genome sequence has a total length of 498.99 megabases. Most of the assembly (96.45%) is scaffolded into 31 chromosomal pseudomolecules, including the W and Z sex chromosomes. The mitochondrial genome has also been assembled, with a length of 15.62 kilobases. This assembly was generated as part of the Darwin Tree of Life project, which produces reference genomes for eukaryotic species found in Britain and Ireland
Local flow estimation at the top of the Earth’s core using Physics Informed Neural Networks
Full text linkThe Earth’s main geomagnetic field arises from the constant motion of the fluid outer core. By assuming that the field changes are advection-dominated, and that diffusion only plays a minor role, the fluid motion at the core surface can be related to the secular variation of the geomagnetic field, providing an observational approach to understanding the motions in the deep Earth. The majority of existing core flow models are global, showing features such as an eccentric planetary gyre, with some evidence of rapid regional changes. By construction, the flow defined at any location by such a model depends on all magnetic field variations across the entire core–mantle boundary: because of this nonlocal dependence of the flow on the magnetic field, it is very challenging to interpret local structures in the flow as due to specific local changes in magnetic field. Here we present an alternative strategy in which we construct regional flow models that rely only on local secular changes. We use a novel technique based on machine learning termed Physics-Informed Neural Networks (PINNs), in which we seek a regional flow model that simultaneously fits both the local magnetic field variation and dynamical conditions assumed satisfied by the flow. Although we present results using the Tangentially Geostrophic flow constraint, we set out a modelling framework for which the physics constraint can be easily changed by altering a single line of code. After validating the PINN-based method on synthetic flows, we apply our method to the CHAOS-8.1 geomagnetic field model, itself based on data from Swarm. Constructing a global mosaic of regional flows, we reproduce the planetary gyre, providing independent evidence that the strong secular changes at high latitude and in equatorial regions are part of the same global feature. Our models also corroborate regional changes in core flows over the last decade. In our models, we find that the azimuthal flow under South America has changed sign quasi-periodically, with a recent sign change in 2022. Furthermore, our models endorse the existence of a dynamic high latitude jet, which began accelerating around 2005 but has been weakening since 2017
Early warming over the Southern Ocean during the last deglaciation
Full text linkThe last deglaciation, ca. 17,000–11,000 years before present (yr BP), marks the most recent period of large-scale climate reorganization on Earth. However, the timing and spatial patterns of the initial warming preceding these changes remain uncertain. Here, we develop a new method using Gaussian Mixture Model clustering to objectively segregate a reanalysis and climate model simulations, respectively, into four distinct patterns of temperature change throughout the last deglaciation. Our findings indicate that the earliest warming signs appeared around 21,000 years BP in the Southern Hemisphere high latitudes. This early warming was accompanied by a cooling in the Northern Hemisphere high latitudes, resulting in a hemispherically asymmetric temperature pattern. Further analysis using single-forcing climate simulations suggests that the early warming and sea ice retreat were likely driven by a weakening in the Atlantic Meridional Overturning Circulation, linked to orbital forcing
The use of ATR-FTIR to track the degradation of single-use polystyrene cup lids during 24 months of temperate outdoor exposure
Full text linkA set of unused virgin polystyrene coffee cup lids were distributed in the environment (Sutton Bonington, UK) for a period of 24 months to compare monthly degradation rates across four treatments with variable degrees of exposure to natural UV irradiance (full or reduced exposure) and soil (surface or buried). Analysis of monthly samples (hole-punched discs) from three lids of each treatment via FTIR-ATR indicated that the lids in each treatment displayed varying levels of degradation, ranked as follows: exposure on the ground surface, no shading > exposure on the ground surface, shading> both buried treatments. Principal component analyses (PCAs) and the carbonyl index indicated that photooxidation via sunlight exposure was the primary degradation mechanism for polystyrene under these environmentally relevant conditions. Monthly variations in spectra for each treatment (particularly surface treatments) also indicated that degradation rate was not a continuous process, with a multiple regression establishing correlation between monthly carbonyl index for the first 12 months of the experiment, and both UV irradiance and temperature (p = 0.058). This demonstrated that environmental polystyrene degradation rate was closely related to seasonal cycles in the temperate environment
Soil microbial community responses to active and passive restoration of selectively logged Bornean tropical forest
Full text linkTropical rainforests support critical biogeochemical cycles regulated by complex plant-soil microbial interactions but are threatened by global change. Much of the uniquely biodiverse and carbon rich forest on Borneo has been lost through extensive conversion to monoculture plantation, and a significant proportion of the remaining forest has been heavily modified by selective logging. Ecological restoration of tropical forest aims to return forests to a near pristine state, but restoration initiatives are hindered by limited understanding of the underpinning plant-soil feedbacks, and impacts on soil microbial communities are unresolved. We characterized soil properties and soil bacterial and fungal communities using amplicon sequencing across adjacent old-growth and selectively logged lowland dipterocarp forest in Borneo undergoing either natural regeneration or restoration by enrichment planting. While many soil properties were similar across forest types, we found contrasting responses of different soil microbial groups to active and passive restoration. Bacterial and fungal community composition were generally distinct in old-growth forest and more similar in logged forest. Bacterial alpha diversity and rate of spatial turnover appeared to recover toward old-growth forest with active restoration, while fungal alpha diversity showed slower signs of recovery. The composition and rate of spatial turnover in mycorrhizal communities was most different between old-growth and actively restored forest, possibly resulting from mycorrhizal associations of tree species planted during restoration. Surprisingly, old-growth forest shared fewer microbial taxa with actively restored forest than with naturally regenerating forest, suggesting current restoration practices (removal of lianas and understorey vegetation) may be selecting for different microbial communities. Taken together, our findings show that certain attributes of key soil microbial groups remain distinct from old-growth forest almost two decades after logging disturbance, and some may diverge with active restoration. Changes in enrichment planting practices to promote rehabilitation of belowground communities may be required for successful biodiversity conservation and recovery of vital ecosystem functions
Personalised estimates of dosage within a population-based cohort suggest limited evidence that drinking water chemistry modulates health outcomes
Full text linkAccess to clean drinking water is crucial for human health, but there are concerns that consumption levels of particular solutes may be linked to negative health outcomes. Many studies use data aggregated to area-level to assess consumption-health associations, but these do not account for differences in behaviour between individuals. Therefore, we combined publicly reported tap water chemistry from compliance data with estimated drinking water consumption within the home calculated from a water habits survey for 1970 UK adults from the TwinsUK cohort. The resulting average daily dose (ADD) estimate of key solutes (including nitrate, hardness, chlorine, selenium), multiple solutes dimensionally reduced to k-means clusters, and ingestion rate (IngR) were used as predictors in nested regression analysis, including stratification for employment status (as a proxy for time spent and home) and adjustment for age. Health outcomes included cardiovascular disease (CVD), CVD risk factors, eczema, sarcopenia, frailty, gastrointestinal disease and cancer. We found estimation of ADD significantly changed the distribution of solutes (ks-tests p < 0.001). Overall, we identified few associations with health outcomes, with mixed or inconsistent signals across nested models. There were some exceptions, including increased odds of hardness predicting CVD risk factors in our employment strata (Hardness ADD OR:1.25, 1.09–1.48, p < 0.002; age-adjusted OR: 1.22, 1.05–1.4, p < 0.002) and eczema negatively associated with IngR in non-stratified models (IngR OR: 0.86, 0.77–0.96, p < 0.01). We found no evidence of difference in ADD in twins discordant for health outcome. The lack of significant findings in solute-health pairings could be inferred as a positive result that supports UK drinking water as a safe source of hydration and therefore our results represent a positive public health outcome. Our study demonstrates an effective approach to estimate personalised exposure to water solutes that can inform researchers designing similar studies
Synergistic pesticide effects on complex arthropod trophic interactions in arable systems
No full textArable systems have a high dependence on diverse natural biota to support pest control, soil bioturbation, and nutrient recycling. However, pesticide regulatory assessments fail to consider complex trophic interactions, underestimating real-world risks. This problem may be exasperated when mixtures of pesticides interact synergistically. Using model arable communities of pests (aphids and weevils), predators (e.g., beetles, spiders, and mites), and soil biota (including mites and earthworms), we assess the impacts of synergistic interactions between a pyrethroid insecticide (cypermethrin) and fungicides (Azoxystrobin and Prochloraz). The impacts of these mixtures on biological control, the biomass of major invertebrate trophic groups, and soil ecosystem processes were additive. However, the architecture of predatory arthropod trophic interactions was simplified in response to synergisms between the pyrethroid and fungicides. Synergisms may act through multiple potential mechanisms to impact food web structure. This may include not only toxicity but also detoxification of pyrethroids within the soil, as well as indirect effects mediated through the loss of critical fungal food resources for detritivores. These findings emphasize the need to consider complex community structure endpoints when assessing system risk to safeguarded agri-ecosystems
Role of soil moisture gradients in favoring mesoscale convective systems in east China
Full text linkMesoscale convective systems (MCSs) contribute significantly to summer precipitation in the tropics and midlatitude. Although soil moisture (SM) effects on convection are globally recognized, its specific role on mature MCSs in East China remains unclear. Using convection-permitting simulations spanning 22 summers, we find that convective cores within mature MCSs preferentially develop on the drier side of strong SM gradients (∼200 km). This is evidenced by a 2.5-fold increase in core occurrences downstream of the steepest 10% of SM gradients versus a near-uniform surface. SM gradients shape sensible heat flux gradients via evapotranspiration, while upstream pre-storm rain-producing clouds suppress surface available energy. These processes favor MCSs through enhancing near-surface temperature gradients which strengthen moisture convergence and zonal wind shear. Our results highlight the critical role of SM gradients in favoring MCS propagation in East China. As climate change intensifies SM heterogeneity, improved land-surface representation offers potential for advancing rainfall prediction and projection
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