An anomalous warm weather event in the Antarctic McMurdo Dry Valleys on 18 March 2022 created an opportunity to characterize soil biota communities most sensitive to freeze-thaw stress. This event caused unseasonal melt within Taylor Valley, activating stream water and microbial mats around Canada Stream. Liquid water availability in this polar desert is a driver of soil biota distribution and activity. Because climate change impacts hydrological regimes, we aimed to determine the effect on soil communities. We sampled soils identified from this event that experienced thaw, nearby hyper-arid areas, and wetted areas that did not experience thaw to compare soil bacterial and invertebrate communities. Areas that exhibited evidence of freeze-thaw supported the highest live and dead nematode counts and were composed of soil taxa from hyper-arid landscapes and wetted areas. They received water inputs from snowpacks, hyporheic water, or glacial melt, contributing to community differences associated with organic matter and salinity gradients. Inundated soils had higher organic matter and lower conductivity (p < .02) and hosted the most diverse microbial and invertebrate communities on average. Our findings suggest that as liquid water becomes more available under predicted climate change, soil communities adapted to the hyper-arid landscape will shift toward diverse, wetted soil communities.

Intervertebral disc degeneration (IVDD) is a globally prevalent disease, yet achieving dual repair of tissue and function presents significant challenges. Considering reactive oxygen species (ROS) is a primary cause of IVDD, and given the decrease of nucleus pulposus cells (NPCs) and extensive degradation of extracellular matrix (ECM) during IVDD development, the present study, inspired by the seeds-and-soil strategy, has developed NPCsloaded TBA@Gel&Chs hydrogel microspheres. These microspheres serve as exogenous supplements of NPCs and ECM analogs, replenishing seeds and soil for nucleus pulposus repair, and incorporating polyphenol antioxidant components to interrupt the oxidative stress-IVDD cycle, thereby constructing a microsphere system where NPCs and ECM support each other. Experiments proved that TBA@Gel&Chs exhibited significant extra-cellular ROS-scavenging antioxidant capabilities while effectively upregulating intracellular antioxidant proteins expression (Sirt3 and Sod2). This dual-action antioxidant capability effectively protects the vitality and physiological functions of NPCs. The therapeutic effects of microspheres on IVDD were also confirmed in rat models, which was found significantly restore histological structure and mechanical properties of degenerated discs. Additionally, RNA-seq results have provided evidences of antioxidant mechanism by which TBA@Gel&Chs protected NPCs from oxidative stress. Therefore, the NPCs-loaded TBA@Gel&Chs microspheres developed in this study have achieved excellent therapeutic effects, offering a paradigm using antioxidant biomaterials combined with cellular therapy for IVDD treatment.

The frequent occurrence of earthquakes worldwide has rendered highway slope protection projects highly vulnerable to damage from seismic events and their secondary disasters. This severely hampers the smooth implementation of post-disaster rescue and recovery efforts. To address this challenge, this study proposes a comprehensive method for assessing seismic losses in slope protection projects, incorporating factors such as topography and elevation to enhance its universality. The method categorizes seismic losses into two main components: damage to protection structures and costs associated with landslide and rockfall clearance and transportation. This study estimates the cost range for common protection structures and clearance methods under general conditions based on widely recognized quota data in China. It establishes criteria for classifying the damage states of protection structures and provides loss ratio values based on real-world seismic examples and expert experience, constructing a model for assessing damage losses. Additionally, by summarizing the geometric characteristics of soil and rock accumulations on road surfaces, a method for estimating landslide volumes is proposed, considering the dynamic impact of slope gradients on clearance and transportation volumes, and a corresponding cost assessment model for clearance and transportation is developed. The feasibility and reliability of the proposed method are verified through two case studies. The results demonstrate that the method is easy to implement and provides a scientific basis for improving relevant standards and practices. It also offers an efficient and scientific tool for loss assessment to industry practitioners.

Debris flows are a type of natural disaster induced by vegetation-water-soil coupling under external dynamic conditions. Research on the mechanism by which underground plant roots affect the initiation of gulley debris flows is currently limited. To explore this mechanism, we designed 14 groups of controlled field-based simulation experiments. Through monitoring, analysis, calculation, and simulation of the changes in physical parameters, such as volumetric water content, pore-water pressure, and matric suction, during the debris flow initiation process, we revealed that underground plant roots change the pore structure of soil masses. This affects the response time of pore-water pressure to volumetric water content, as well as hydrological processes within soil masses before the initiation of gully debris flows. Underground plant roots increase the peak volumetric water content of rock and soil masses, reduce the rates of increase of volumetric water content and pore-water pressure, and increase the dissipation rate of pore-water pressure. Our results clarify the influence of underground roots on the initiation of gulley debris flows, and also provide support for the initiation warning of gully debris flow. When the peak value of stable volumetric water content is taken as the early warning value, the early warning time of soil with underground plant roots is delayed by 534 to 1253 s. When the stable peak value of pore-water pressure is taken as the early warning value, the early warning time of soil with underground plant roots is delayed by 193 to 1082 s. This study provides a basis for disaster prevention and early warning of gully debris flows in GLP, and also provides ideas and theoretical basis under different vegetation-cover conditions area similar to GLP.

Ciprofloxacin (CIP) is an antibiotic used in both human and veterinary medicine. Because it is only partially metabolized, it has been found in sewage sludge, manure, and agricultural soils. Therefore, due to the high persistence and low mobility of CIP in soil, we aimed to evaluate its long-term effect on Enchytraeus crypticus. Three multigenerational and one transgenerational test were performed according to OECD 220 guidelines (2016) on sandy clay soil. The concentrations tested were 0.1, 1.0, 10.0, 100.0, 1000.0 and 5000.0 mg kg- 1 dry soil. For F1, statistical analysis showed differences between the control and all concentrations tested, but no differences among the concentrations. For F2, there was a difference between control and 10 mg Kg -1 and for 10.0 mg Kg -1 compared to 0.1, 1.0 and 5000.0 mg Kg -1. For F3, no statistical difference was observed between any of the concentrations. When comparing the generations among themselves, there were significant differences between F1 and F2 and F1 and F3 for all concentrations. For the transgenerational test, there was no statistical difference between the control and the concentrations tested, nor among the concentrations. We verified a negative effect of CIP on the reproduction of E. crypticus for the first generation, which could be related to oxidative stress, DNA damage and clay content. We also verified that the organisms could develop a tolerance to CIP and that the effects of high clay content could outweigh the effects of CIP in long-term exposure. Due to the high persistence and low mobility of CIP on soil, it may affect other organisms and promote antibiotic resistant genes (ARGs) regardless of E. crypticus tolerance. Therefore, we strongly recommend further studies focusing on long-term effects on different organisms, with a molecular approach, and in different soil types.

It has not been known how immune responses in soil invertebrates occur against microplastics (MPs). This study aims to investigate the effects of MPs on endocytosis, including phagocytosis and pinocytosis, of immune cells of soil invertebrates in the soil ecosystem in the process of bacterial infection. We employed polystyrene micro- plastics (similar to 1 mu m PS MPs) to treat earthworm Eisenia andrei during the infection of Escherichia coli for in vitro (1, 5, 10, and 50 mg/L) and in vivo (1, 10, and 1000 mg/kg dry soil) assays. The results of in vitro migration assay revealed that MPs caused inhibitory effects on the phagocytosis, pinocytosis and oxidative stress in coelomocytes. Soil bioassay also confirmed that endocytosis of coelomocytes and mitochondrial damages in the intestinal epithelium were significantly altered in the polluted soil with MPs. Thus, MPs induced adverse effects to inhibit bacterial endocytosis, which may disturb the immune system of soil invertebrates. This study is the first report on the inhibition of phagocytosis in the soil invertebrates by MPs. These findings contribute to understanding the response of soil invertebrates, which play important roles in the soil food web with cellular level towards microplastic pollution in soil.

Debris flows are catastrophic mass movements with significant social and environmental consequences, particularly in the Western Himalayas. Understanding the rheological properties of debris flow material is crucial for accurately modeling their behavior and predicting their impacts. In this study, rheological parameters such as yield stress and viscosity were determined through extensive laboratory testing using a parallel plate setup in a rheometer. Reconstituted soil samples from the debris flow zone were prepared using an optimized sampling approach to vary the solid volume concentration and water content (w/c). Experimental results revealed non-Newtonian behavior for all tested compositions, which closely aligned with the Herschel-Bulkley rheological model. The Herschel-Bulkley parameters were subsequently used to calibrate a smooth particle hydrodynamics (SPH) model in the open-access DualSPHysics tool. The results showed that water content and silt concentration played a significant role in influencing the rheology, with finer particles exhibiting higher viscosity and shear stress compared to coarser particles. The SPH simulations effectively replicated the flow behavior observed during the Kotrupi debris flow event (2017), providing insights into flow dynamics, such as velocity and shear distribution. This integration of experimental rheology and numerical modeling advances our understanding of debris flow mechanics and highlights the importance of incorporating rheological calibration in predictive debris flow models.

Collapse pits are highly susceptible to secondary hazards such as underground debris flows and slope instability under mining disturbances. These hazards significantly damage the ecological environment of the mining area. To reduce the geological hazards of collapse pits, grouting is used for management. The diffusion pattern and curing mode of slurry under different grouting pressures were investigated through indoor grouting simulation tests, and industrial tests were carried out to assess grouting effects. The results indicate that the slurry is dominated by penetration diffusion and supplemented by splitting diffusion in the moraine. The penetration distance and diffusion radius of the slurry increase linearly with grouting pressure, while the splitting uplift distance and cured volume increase exponentially with grouting pressure. Splitting diffusion consists of three stages: bulging compaction, splitting flow, and passive uplift. Horizontal splitting has a vertical uplift effect on the formation. The slurry primarily consolidates individual moraine particles into a cohesive mass by filling fractures, binding soil particles, and reinforcing interfaces with the rock mass. For different moraine layer structures, full-hole, segmented, and point-based grouting methods were applied. A composite grouting technique, layered grouting with ring solidification, was also introduced, achieving excellent grouting results. This study provides technical support for managing geological hazards in collapse pits caused by block caving mining disturbances and for green mining practices.

Rainfall-induced debris slides are a major geological hazard in the Himalayan region, where slopes often comprise heterogeneous debris-a complex mixture of rock and soil. The complex nature makes traditional soil or rock testing methods inadequate for assessing such debris's engineering behaviour and failure mechanisms. Alternatively, reduced-scale flume experiments may aid in understanding the failure process of debris slopes. Here, we present findings from reduced-scale laboratory flume experiments performed under varying slope angles (ranging from shallow to steep), initial volumetric water contents (ranging from dry to wet), and rainfall intensities (ranging from light to heavy) using debris materials with a median grain size (D50) 20.7 mm sampled from a rainfall-induced debris slide site in the Himalayas. Hydrological variables, including volumetric water content and matric suction, were monitored using sensors, while slope displacement was tracked indirectly, and rainfall was monitored using rain gauges. The entire failure process was captured via video recording, and index and shear strength tests were performed to characterize the debris material. Our results reveal that the failure of debris slopes is not driven by sudden increases in pore water pressure but by the loss of unsaturated shear strength due to reduced matric suction and a decreased frictional strength from reduced particle contact between grains during rainfall. We also find that the saturation of debris slope by rainfall was quick irrespective of the slope angles and initial moisture contents, revealing the proneness of debris slopes to rainfall-induced failures. These findings provide critical insights into the stability of debris materials and have important implications for improving risk assessment and mitigation strategies for rainfall-induced debris slides in the Himalayas and similar regions worldwide.

Different types of mass flow-like movements are often triggered by rainfall in the same mountain basin in different seasons of the year, ranging from debris flows to hyper-concentrated flows and flash floods. Despite some similarities, such as large runout and high velocity, these natural hazards are different in their propagation mechanisms. Landslide mass and materials eroded along the path may be deposited along the channel(s) and subsequently remobilised; in other cases, runoff and debris mix inside the channels or nearby the protective structures. Such combined processes are typical along the northern Italian Alps but also in steep catchments in Liguria, Campania and Calabria regions. In this work, a two-phase mathematical framework is adopted to simulate the propagation of solid and water mixtures along a 3D terrain model. The mass and momentum conservation equations are solved by including the rheological behaviour models of the materials involved: frictional for soil, Newtonian for water. Selected scenarios are presented for a case study in Southern Italy with a discussion provided on how solid concentration of flow-like mass movements evolves in a mountain catchment. Numerical results show that at first, the runoff water accumulated within the natural channels and then a debris flow propagated rapidly down the slope meanwhile the concentration of solid material decreased due to the addition of runoff water and a hyperconcentrated flow reached the foothill area, later even more diluted and capable to move several kilometres far until it almost reached a railway line.